Full text of "The utilization of wood waste by distillation; a general consideration of the industry of wood distilling, including a description of the apparatus used and the principles involved, also methods of chemical control and disposal of the products"

LIBRARY

OF THK

UNIVERSITY OF CALIFORNIA.

Class

A GENERAL CONSIDERATION

... OF THE . . .

Utilization of Wood Waste

by Distillation

A General Consideration of the Industry of
Wood Distilling, including a description of the
apparatus used and the principles involved

...ALSO...

METHODS OF CHEMICAL CONTROL
AND DISPOSAL OF THE PRODUCTS

...BY...

WALTER B. HARPER, M. S.

First Edition
Illustrated by Seventy-four Engravings

1 IRA. j|>^

OF THE

UNIVERSITY |

OF /

ST. LOUIS, MO..
JOURNAL OF COMMERCE COMPANY

PUBLISHERS
ST. LOUIS LUMBERMAN

BY
JOURNAL OF COMMERCE CO.

ST. LOUIS, MO.

CONTENTS

CHAPTER I. Page

Introduction 17

CHAPTER II.

Historical Connection 18-19

CHAPTER III.
Principles of Distillation 20-25

CHAPTER IV.

Apparatus Necessary for Destructive Distillation 26-40

Swedish Oven / .-...' 27

Vertical Retort 30

Charcoal Coolers 31

Condensers 33

Box Condenser 34

Worm 34-35

Counter Current Pipe Cooler 36

Tubular Condenser 37

Receivers and Storage Tanks 40

CHAPTER V.

Refining Methods 41-49

Turpentine Stills 41

Tar Stills 44

Wood Oil Stills 45

Still Heads 45

Alcohol Stills and Acetate Pans 47

Condensers 47

Storage Tanks 48

Condensing Water 48.

Shipping and Packages 49

CHAPTER VI.

Special Combinations of Apparatus as Used in Modern Plants 50-101

Steam Processes 51

Steam and Destructive Distillation and Destructive Distillation Plants. 57

Horizontal Retorts 58

Vertical Retorts 69

Special Retorts and Processes . . 83

Rotary Processes 84

Movable Retorts 93

Conveyor Processes 96

Pierce Process -. 100

Patents 100-101

CHAPTER VII.

The Execution of the Processes of Wood Distillation 102-109

The Steam Process 102

Steam and Destructive Distillation 104

Special Process 107

Wood Gas Making 107

CHAPTER VIII.

Refining Processes . . . '. 110-112

Mallonee's Apparatus 110

Gilmer's Refining Process Ill

Heber's Process . 112

CONTENTS

CHAPTER IX. Page

General Consideration for the Establishment of a Plant 113-119

Market Conditions 117

Steam Plant 118

CHAPTER X.

Composition of Wood and Products of Distillation 120-133

Gases 121

Wood Oil, and Tar 121

Wood Vinegar and Wood Alcohol 122

Residue 122

Turpentine 123

Pinene 124

Dipentene 125

Sylvestrene 125

Pine Oil 126

Resin Oil 126

Rosin 127

Rosin Spirit 127

Rosin Oil 128

Tar 129

Pitch 130

Pyroligneous Acid 130

Acetone 131

Calcium Acetate 132

Charcoal 132

CHAPTER XI.

Yields and Disposals of Products 134-138

CHAPTER XII.

Chemical Tests and Combinations 139-147

Combinations or derivatives 140

Wood Residues 143

CHAPTER XIII.

Chemical Control of Plant for the Distillation of Wood 148-156

Measurements 148

Sampling 149

Standardizing Apparatus 149

Analysis 150

Acetates 153

Wood 153

Moisture 153

Creosote 155

Acetone 156

Bibliography 157

ILLUSTRATIONS

Page

Fig. 1, Water Still 20

Fig. 2, Retort and Worm 21

Fig. 3, Italian Charcoal Kiln 21

Fig. 4, Horizontal Charcoal Kiln 22

Fig. 5, Tar Kilns 23

Fig. 6, Bee Hive Oven 24

Fig. 7, Rectangular Brick Kiln 25

Fig. 8, Swedish Oven 27

Fig. 9, Horizontal Retort 29

Fig. 10, Vertical Retort 30

Fig. 11, Connections 31

Fig. 12-A, Separator 32

Fig. 12-B, Separator 32

Fig. 12-C, Separator 33

Fig. 13, Box Condenser 35

Fig. 14, Double Pipe Counter Current Condenser 36

Fig. 15, Connection of Counter Current Pipe Cooler 37

Fig. 1C, Tubular Condenser 38

Fig. 17, 750 Gallon Steam Heated Turpentine Refining Still 41

Fig. 18, Still Heads 45

Fig. 19, Hege's Patent Head 46

Fig. 20, Shipping Turpentine and Tar at a Steam and Destructive Dis-
tillation Plant 49

Fig. 21, Krug's Patent (Plan) 52

Fig. 22, Hoskins Patent 53

Fig. 23, Mallonee's Process 54

Fig. 24, Hirsch's Process 55

Fig. 25, Gardner's Process 56

Fig. 26, James' Process 56

Fig. 27, McMillan's Process 57

Fig. 28, Wheeler's Process 58

Fig. 29, Messau's Process 59

Fig. 30, Hansen & Smith Process 60

Fig. 31, Koch's Process 61

Fig. 32, Badgley's Process 61

Fig. 33, Inderleid's Process 62

Fig. 34, Chapman's Process 62

Fig. 35, Gilmer's Process 63

Fig. 36, Broughton's Process 64

Fig. 37, Mallonee's Process (Fig. 1) 65

Mallonee's Process (Fig. 2 66

Mallonee's Process (Fig. 3) 67

Mallonee's Process (Fig. 4) 67

Fig. 38, Palmer's Process 68

Fig. 39, Hessel's Process 69

Fig. 40, Roake's Process 69

Fig. 41, Bilfinger's Process 70-71

Fig. 42, Palmer's Process 72

Fig. 43, Douglas's Process 73

Fig. 44, Clark & Harris Process 74

Fig. 45, Sibbitt & McLean 75

Fig. 46, Friis Process 76

Fig. 47, Ross & Edwards Process 77

Fig. 48, Mathieu's Process 77

Fig. 49, Jewett Process 78

Fig. 50, Fiveash Process 78

Fig. 51, Williams's Process 79

Fig. 52, Snyder's Process 79

Fig. 53, Copilovich Process 80

Fig. 54, Denny's Process 81

ILLUSTRATIONS

Page

Fig. 55-A, The Krug Steam Process Showing Retorts 82

Fig. 55-B, The Krug Steam Process, Showing Condensers 82

Fig. 56, Steam and Destructive Process, Using Coolers and Cars 83

Fig. 57, Berry's Process 84

Fig. 58, Spurrier's Process 85

Fig. 59, Larsen's Process 86

Fig. 60, Halliday's Apparatus 87

Fig. 61, Viola Process 88

Fig. 62, Harper's Process 89

Fig. 63, Fleming's Process 90

Fig. 64, Jackson's Process 91

Fig. 65, Handford's Process y2

Fig. 66, Smith's Process (Fig. 3 and Fig. 5) 93

Fig. 67, Davis' Process 94

Fig. 68, Weed's Process 95

Fig. 69, Hale & Kursteiner Process 96

Fig. 70, Dobson's Process < 97

Fig. 71, Kerr's Process 98

Fig. 72, German Destructive Distillation Plant 105

Fig. 73, Mallonee's Refining Process 110

Fig. 74, Gilmer's Refining Process Ill

OF THE

UNIVERSITY

PREFACE

The lack of literature on the subject of wood distillation, particu-
larly that which relates to the treatment of resinous woods, led the au-
thor to believe that a description of the various processes that have been
used or suggested to accomplish this purpose might be interesting and
acceptable to many.

In the pine wood industry so much money has been wasted trying to
carry out successfully the plans of over-enthusiastic promoters that it is
well to direct along sane lines of investment any further capital that may
be advanced for distillation processes. Great and wonderful results have
been promised by promoters and in most cases the processes tried did not
even yield a small profit. This bad result has been caused chiefly by the
fact that those who have experimented with the various processes on the
small scale have made erroneous deductions from the results obtained.
Usually some feature that is essential to success has been overlooked and
when the process is started on a large scale this feature is brought out so
prominently that it cannot be successfully overcome and the plant fails.
The greatest mistake is usually the estimation of the cost and quantity
of the particular grade of wood with which the experiment was made.
It usually develops that a sufficient quantity of wood of the right qual-
ity cannot be obtained. Many of these essential conditions for success
are pointed out in the text.

The lumbermen should be the most interested as they control the
forests. The great inducement to lumbermen to enter the business is to

PREFACE

dispose of the vast quantity of refuse incident to the milling operations.
The advisability of treating refuse will depend upon the quantity and
its use for fuel. With the use of band mills and lath mills, the amount
of refuse is getting to be so small that it is hardly sufficient to supply

enough fuel to furnish the power for the mill. All distilling processes

/
take considerable fuel, consequently it is only at those mills where the

refuse has no value as fuel that it would pay to install a distilling appa-
ll

ratus. The discussion of these features is brought out in the book.

In the forest no successful method has been discovered to utilize pine
or fir wood, taking the wood as it comes without selection and only such
a process could be called a success economically. It is to be hoped that
rotary processes may achieve that end, but the outlook is not promising.

It has been the author's intention to write this book in such a man-
ner that the different phases of the subject might be touched upon and
easily comprehended by an unscientific person. With the information
herein obtained it might be possible for him, if suitably located, to estab-
lish a distilling plant on a sound basis. On the other hand, this infor-
mation may save some parties from a loss in a contemplated investment.
Furthermore the book ought to act as a stimulus to those who are al-
ready engaged in the industry.

Most of the credit for the success of the book is due to Mr. W. E.
Barns on account of his interest in the matter and the expense incurred.

A great deal of information on the subject has been taken from the
articles contained in the columns of the periodicals given in the append-

PREFACE

ed list. The purpose of the author has been to give the opinions of others
prominence, when in accord with facts. More explicit information relat-
ing to these articles would probably be acceptable, but in many cases
the author had only clippings without date.

The author expresses his thanks to Dr. C. E. Coates of the Louisiana
State University, for the use of his library, from which a great deal of
the chemical information herein contained has been derived.

The arrangement of the contents might have been improved by com-
bining all the information concerning a certain product under one
head. However, the information required can in most cases be easily
found by consulting the index and table of contents.

WALTER B. HARPER.
Laboratory of the La. State University.

BATON ROUGE, April, 1907.

OF THE

UNIVERSITY

THE UTILIZATION OF WOOD WASTE
BY DISTILLATION.

CHAPTER I.

INTRODUCTION.

In the discussion of this subject the chief wood
that will be considered is the long leaf yellow pine
or Georgia pine, although some reference will b"
made to other kinds of wood.

The pine contains so much more gum and resin
that it offers more opportunity for successful dis-
tillation than those kinds of woods which contain
few of these substances. On account of the abund-
ance of raw material any successful method of
using the vast quantity of waste pine would be of
great importance as an aid to the material welfare
of the nation, and particularly to the South. The
importance of this problem has now been partly
realized by a large number of individuals. Some
lumber companies in the South have already made
investigation of the problem, but as yet none have
decided fully what is the best method of utilization.

Distillation of the wood in closed vessels, al-
though of very ancient origin, has been brought
forward as a new means of practically disposing

of this waste product. The increasing demand and
consequently increasing price of spirits of tur-
pentine have led manufacturers to seek some sub-
stitute. As an oil closely resembling turpentine can
be obtained from pine wood, and even fallen and
dead pine by distillation by heating with steam
or direct heat, this method has the double advantage
to the country of supplying a substitute for a com-
modity, the supply of which is evidently failing and
at the same time utilizing a material that has been
almost worthless heretofore. We give a description
then of some of the attempts that have been made
to produce a successful process of distillation. A
great deal has been done, but there are many points
to be worked up before a complete utilization can
be obtained by this means. It is almost impos-
sible to calculate the amount of raw material ob-
tainable for this purpose, but in the South there
are fully 1,000,000 cords that are annually going
to waste either as saw dust or as fallen timber.

CHAPTER II.

HISTORICAL CONNECTION.

Probably the ancients noticed the fact that is
so apparent to all who have made wood fires that
wood chars on heating to a black coal. There then
was noticed that a slow fire left more coal when it
went out; after this in attempts to smother fires
with dirt larger quantities of charcoal were pro-
duced, thus leading to the method that is even
now prevalent of making charcoal by smothering
lighted piles of wood with earth. We have charcoal
produced in the South today by stacking wood
and covering it with earth and igniting the wood
at the bottom of the pile. This method of treating
wood sufficed to attain the object intended that
of producing charcoal. That the vapors and gases
produced were of any particular value, except per-
liaps to smoke meat, was not known until a
much later date. Glauber in Miraculum Mundi,
1658, noticed the presence of pyroligneous acid in
the cooled vapors, and Thenard in 1802 showed that
this acetic acid, or pyroligneous acid, was the same
.as that made from alcohol ; but it was not until the
\discovery of the presence of methyl alcohol by
Taylor, 1812, that much attention was given to the
recovery of the vapors. We find, though, that M.
Philip Lebon in 1799 made use of the gas. and ir.
1801 he lighted his house with gas from wood. The
gas was of low candle power as then produced, but
Pettenkofer in 1849 showed that by rapid heating of
the wood a much more luminous gas was formed,
and this gas was used for a time in some of the
old German cities.

A great many researches on the destructive dis-
tillation of wood have been made by Violette, Vin-
cent, Stolze and others. As a result of these ir.
vestigations it has been generally observed that
lor the production of gas and charcoal chiefly the
distillation should be performed quickly in small
apparatus as this affords means of quickly heat-
ing the wood; but for the production of oils and
acetic acid large retorts heated slowly are better.

That the method of firing influenced the quantity
and nature of the distillate is shown by the fol-
lowing table:

Wood
100 Parts.

J.UV JTcLL U3.

5 a

2 -a i
till

|||

o
cti >>

S <n

QJ
03

Hornbeam

Slow

52.40

4.75

47.68

6.43

25.37

22.23

Fast

48.52

5.55

42.97

5.23

20.47

31.01

Birch-

Slow

51.05

5.46

45.59

5.63

29.64

19.71

Fast

42.98

3.24

39.74

4.43

21.46

35.56

Beech

Slow

51.65

5.85

45.80

5.21

26.69

21.66

Fast

44.35

4.90

39.45

3.86

21.90

33.75

Oak-

Slow

48.15

3.70

44.45

4.08

34.68

17.17

Fast

.45.24

3.20

42.04

3.44

27.73

27.03

Larch

Slow,

.51.61

9.30

42.31

2.69

26.74

21.65

Fast

43.77

5.58

38.19

2.06

24.06

32.17

Spruce

Slow

.46.92

5.93

40.99

2.30

34.30

18.7S

Fast

.46.35

6.20

40.15

1.78

24.24

29.41

The above is from the tables given by Prof.
Fisher in his Chemical Technology. The slow dis-
tillation represents starting with wood in a cold
retort and heating slowly for six hours, and the
fast distillation represents results obtained by plac-
ing the wood in glowing retorts and maintaining
the temperature for three hours. This table will
be of some service to a distiller wishing to know
how he has been firing, as it is only necessary to
compare the results obtained to get a working
idea.

Sftolze's table shows the following results ob-
tained by careful carbonization:

100 Lbs.

Birch 44.9

Beech 44

Hornbeam 42.5

Oak 43

Fir . ...42.3

5 o c o

8.9

. 8.6

24.4

9.8

8.6

9.5

24.6

It7.8

7.6

11.1

23.9

7.7

9.1

26.1

4.2

11.9

26.6

12.5

THE UTILIZATION OF WOOD WASTE BY DISTILLATION,

And Assmus on a manufacturing scale shows as
follows:

a,;

100 L

Birch
Birch

<_ IB
bs. ^J -j

Is" -

t> d
!> be

; o i'

- "^^c

2g3(S

5.2

^ Acetic
hydride

d
8

co Charco
& Pounds

m
W"

1.2

93 f
C

4.5

bark

1st

extract. 22

0.6

0.4

18.5

21.6

Birch

bark

2nd
Oak
Fir ,
Pine

extract. 20
42

0.7
6.0
3.2
3.0

0.5
4.5
2.4
2.3

20
8.8
10.5
9.5

22
27.5
22
22.6

12
0.8
1.3
0.6

4.7
3.3
5.7
3.5

. 44.5

A noticeable feature is the small percentage of
acetic anhydride in the wood vinegar yielded by
the pine and fir; also in Stolze's table the large
amount of gas yielded by fir. These features of the
distillation of these woods explain why distillers
of yellow pine do not try to save the pyroligneous
acid or wood vinegar.

These are some of the results obtained in Euro--
~pean experiments and practice. We are inter-
ested to know of early American attempts to utilize
wood so that we may obtain the benefit of Ameri-
can experience. The manufacture of pyroligneous
acid was begun in the United States by James
Ward in 1830 at North Adams, Mass. The man-
ufacture of acetate of lime and methyl alcohol was
started in the United States by James A. Emmons
snd A. S. Saxon in Crawford county, Pa., and in
"1374 George C. Edwards established the Burcey

Chemical Works at Binghamton, New York, to re-
fine the crude wood spirit produced by the various
acetate manufacturers. In 1876 Dr. H. M. Pierce
obtained a series of United States patents for in-
ventions which he was to apply to the recovery
of the smoke from charcoal kilns in Michigan.
According to the census of 1900 in the Digest of
Patents Relating to Chemical Industries, the name
of M. A. LeBrun Virloy is found as having ob-
tained a patent in 1863 for a special furnace for
carbonizing organic matter. The next one, granted
to A. H. Emory in 1865, shows that turpentine had
been extracted from pine wood before this time.
Several other patents after this mention the dis-
tillation of wood. In 1872 a patent was granted to
J. D. Stanley, which is of especial interest, as he
established a plant at Wilmington, N. C., which,
although it proved a failure, owing to lack of suf-
ficient financial backing and probably other causes,
was transferred in 1878 to the Spiritine Chemical
Co., who have continued it with more or less suc-
cess until the present time. Since then numerous
processes have been promoted, mostly copied from
German or French methods, and each year adds
new patents to the already large list. A descrip-
tion of some of these will be given later as a great
many have some one little point either overlooked
or not mentioned by the others: but first we must
take up the general consideration of distillation in
order to understand more fully the principles upon
which they are based.

CHAPTER III.

PRINCIPLES OF DISTILLATION.

Distillation comprises that process which consists
in heating substances in closed vessels with the in-
tention of converting the substance into vapors and
of condensing these vapors. Sometimes an in-
destructible substance is left as a residue which
is not further acted upon by the degree of heat
used. Sometimes the vapors are composed of dif-
ferent substances than the original, and at other
times when the original substance is composed of
a mixture of materials, the vapors of each separate
^material have a tendency to come off by them-
selves or with other bodies of similar physical
properties.

In all cases of distillation we find that the vapora
formed occupy a great deal more space than when
the substance is in the solid or liquid state. This
is well exemplified in the case of water that is
turned into steam or water vapor; the space being
nearly seventeen hundred times as great when not
compressed. Generally vapors are compared with
the solid or liquids in the ratio of 1,00 J to 1. In de-
signing distilling apparatus this point must be
taken into consideration.

The object of distillation is to separate one sub-
stance from another; consequently it is a method
of purification. Generally in the case of liquids the
substances distill without decomposition, although
not. always so. Sometimes to prevent decomposi-
tion it is necessary to distill under a vacuum. When-
ever the material distilling is overheated decompo-
sition generally ensues. In the case of solid sub-
stances great difficulty is experienced in distilling
them without decomposition. It is only those sub-
stances that are easily melted, or are of an ele-
mentary or mineral nature that can be so distilled.
With organic substances decomposition generally oc-
curs to a more or less extent.

Whenever this decomposition takes place it is
usually called destructive distillation. The result-
ing condensed vapors are called products. When the

resulting condensed vapor exists in the same form
in the original substance it is called an educt. When
a substance is easily converted into a vapor it is
spoken of as being volatile. Some substances can-
not be volatilized, such a substance is wood. This
would be called non-volatile. Heat usually causes
a substance to change to vapor and some substances
become vapors at lower temperatures than others.
Thus in a mixture containing two or more sub-
stances of widely different boiling points one would
expect that the one with the lowest boiling point

FIG 1 WATER STILL.
A Heard.
B Arm.

C Tank and worm.
D Receiver.

would vaporize or distill first. However, with sub-
stances whose boiling points are near together one
may give off a heavy vapor which will retard its
distillation. Owing to this a general rule is given
by Wanklyn that "the quantity of each ingredient
which distills will be found by multiplying its
tension at the boiling point of the mixture by its
vapor density."

To carry out the process of distillation the ap-
paratus consists primarily of five principal parts:
the retort or still; the still head, sometimes very

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

complicated in construction in fractionating stills;
the condenser, comprising tank containing cooling
liquid, if not air-cooled, and the worm, pipe or
other device through which the vapors pass to be
cooled; the receiver, comprising any form of recep-
tacle for catching the products of condensation*
and the connections which are generally pipes con-
necting the various parts.

In Fig. 1 the various parts of a common water
still are shown. This could be used for distilling
other substances as well as water, as it has all the

FIG 2 RETORT AND WORM.

A Retort.

B Arm .

C Tank and Worm.

i) .ueceiver.

necessary parts. All that is necessary is to put the
water in the still, place a fire of some kind under
it, and add the cooling water. Generally there
should be an overflow pipe in the tank so that the
water as it gets hot can be forced over with cold
water admitted at the bottom to take its place.

For destructive distillation a distilling apparatus
would be more of the form shown in Fig. 2. This
form usually has no still-head.

Our object being to distill wood, it is necessary
to proceed by destructive distillation. In the early
treatment of wood no apparatus was used to collect
the vapors, but they were allowed to escape into the
air; the residue left after all the volatile matter .
formed had been distilled was the only valuable
part saved. The earliest arrangement was to cover
over the wood with earth and set fire to it near
the middle of the pile and allow only a limited sup-
ply of air to reach it. In this way the heat from

that part of the wood which is burned distills the
other part, leaving charcoal, as not enough air is
admitted to allow this to burn.

As this method of utilizing the wood may be the
best in some localities, a view of a kiln is herein
presented as illustrated in Wagner's Chemical
Technology. This is called an Italian kiln, as this
form is much used in Italy. It consists of three or
more poles stuck in the ground and separated from
each other by wedges, N Fig. 3. The wood is
stacked on end, as shown, the upper part being
filled in with pieces lying horizontally. The whole
mass is then covered with earth and ignited.

Another form of kiln is the Slavonian, similar to
the Italian kiln, but instead of several poles at the
axis there is usually but one. Also a passage way
is made from the outer edge of the kiln at the bot-
tom to the middle of the pile, thus making it easy
to light the pile in the middle.

A form used in Norway called the Schwarten kiln
is suitable for making charcoal from slabs. For an
axis several planks are tied together and driven

FIG 3 ITALIAN CHARCOAL KILN.
N Wedge.

into the ground; around the axis blocks are built
up to form a cone-shaped mound. Upon this mound
the planks or slabs are placed, leaning on the edges
instead of lying flat, thus enabling the heat to pen-
etrate better into the mass. A kindling passage is
left at the bottom and the whole covered with
earth and ignited.

Considerable experience is necessary to burn a
kiln so as to obtain the most charcoal and to ob-

THE

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

tain it free from brands or not thoroughly charred
pieces. The first thing to do is to drive off the
water with as little heat as possible. Considerable
air must be let in at first in order to give the fire
a good start and cause it to spread rapidly. The
escape of steam and wood vapors make considerable
noise as they escape through the earth covering and
cause the earth to crack and sometimes explode,
making the heap fall in. All exposed places are
quickly covered over. The nature of the vapors
emitted from the cracks determines the progress
of the distillation, so as soon as the watery vapor

and on account of their mound shape, meilers. In
a horizontal kiln, where the wood is simply corded,
we find attempts made to support it by outside
means. A kiln of this type is shown in Fig. 4.
Here the wood is stacked up and a frame made of
posts surrounding it. The posts are connected with
slabs, shingles, boards or even logs, thus forming
an enclosure for the wood. A space is left between
the stacked wood and support and this space filled
with earth, the top also being covered with earth.
One end is usually higher than the other, as is
shown in the illustration. To ignite the heap a

PIG 4 HORIZONTAL, CHARCOAL, KILN.

and the heavy smoke of the next stage changes to a
lighter color there is not much decomposable matter
left. To remove this without burning the charcoal
the air supply is diminished and the heat made as
far as possible to travel from the top to the bot
torn, and from the middle to the circumference.
When the smoke becomes pale and blue no tarry
matter is left except near the edp-es of the kiln, the
blue smoke seen coming from the combustion of
the charcoal itself. To stop this all the airholes
are closed as tightly as possible, and the kiln allowed
to cool off. When sufficiently cooled the earth is
taken off and any glowing charcoal quenched with
water. A kiln requires continuous attention night
and day until finished. The time varies with the *
size of the kilns, some taking as much as two weeks.
On account of the wood in the bottom layers being
stood on end these kilns are called standing kilns

door is left in the smaller end, as shown at C. The
fire once started requires only the attention needed
to stop cracks and to fire evenly. As part of the
wood becomes charred it is taken out through the
small end. This form of kiln is much used in Cen-
tral Europe.

In this country charcoal making in kilns is not
a very remunerative occupation as now carried on.
In the South it is carried on mostly by negroes who
succeed in making enough to keep them from starv-
ing. A kiln, though, such as the Italian form, is
so easily constructed and can be built so near the
raw material that this form has continued to be
popular through the ages. There is no outlay of
capital for apparatus and the covering material is
always at hand. The drawbacks are that a large
amount of wood is burned, the dirt gets into the
charcoal, a great many brands are left and the

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

charcoal being quenched with water easily breaks
up.

A further form of kiln is used in Russia and the
Carolinas for making pine tar. In this kiln the fat
or rich wood is split into small pieces and stacked
in layers. As the mass heats the tar runs to the
bottom and is led by a trough into a barrel or pit
in the ground. This is still a definite industry in
the South and the tar thus produced has a ready
sale. It is a great deal cheaper than it should be be-
cause of its being produced largely by turpentine
hands during the idle season.

Fig. 5 shows two views of such a kiln. A mound
of earth is made and the bottom made V shaped,
forming a sort of trough which inclines toward the
outlet pipe. The bottom is covered with clay and
sometimes shingles, so the tar may be as free as
possible from dirt. The fire progresses from the
outside to the middle, being lighted at the bottom

struction in the earthen kilns, the supported kilns
are to be found in many localities. Instead of mak-
ing a supported wall of boards and earth, as in Fig.
4, brick is used without the addition of earth as a
covering. One of the earliest forms was hemis-
perical, like a brick kiln with the brick left out here
and there near the top for air holes. The wood was
put in at the top and through a door at the bottom
where the pile was ignited. The charge was fired
in the usual way and when finished the charcoal
was allowed to cool and then was taken out through
the door at the bottom.

A form of kiln now in use is the bee hive or cone-
shaped kiln, Fig. 6. These kilns are made of brick,
usually 24 feet in diameter and 24 feet high, hold-
ing about forty cords of wood. The bricks are laid
in a circle two courses thick, one of fire brick and
one of red brick until about half way up when the
remainder is finished with one course of red brick.

FIG 5 TAR KILN.

and the vapors escaping at the top. Most of the
charcoal is consumed, as the chief object is to obtain
the tar. The tar collects at the bottom of the kiln
and is taken out at regular intervals, generally
every morning. It is generally several days before
it commences to run and it is usually hot. To keep
it from igniting it is led at least three feet from any
flame. This tar was usually put in barrels contain-
ing about 320 pounds and made on the spot; now
the tendency is to sell in old oil barrels containing
fifty gallons and quotations are now largely made
on that basis. Notwithstanding the ease of con-

To strengthen the walls bands of iron are placed
at intervals and tightened with a bolt, as shown at
B. It is claimed by some that brick kilns are not
as good as the earth-covered mound or meiler, but
experiments and practice show a yield of 45 bushels
of charcoal against 35 bushels from the meiler, and
at some iron furnaces the charcoal is said to work
better. The difference in the yield is sufficient
to pay for the extra expense for the brick.

In this kiln the two doors shown are of iron and
on hinges. The upper one serves for putting in
wood and the lower one for putting in wood and

THE UTILIZATION 01' WOOD WASTE BY DISTILLATION.

FIG 6 BEE HIVE OVEN.
A Draft holes.
B Tightening bolts.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

taking out the charcoal. At the bottom, spaces are
left for the admission of air; these can be stopped
up with loose brick when necessary.

Another form of brick kiln is shown in Pig. 7.
This is square in front with an arched top. It is
usually built 16 feet wide by 16 feet high and runs
back about 40 feet, outside measure. This will hold
about 80 cords. This size is usually built a brick
and a half thick and supported with 10x10 frame
work timber. The cost of such a kiln in any locality
can be readily calculated. The working of the kiln
is similar to the bee hive, the doors being for
charging and discharging and the holes at the bot-
tom being for the admission of air.

In .all these kilns no attempt was made until re-
cently to save the vapors. In Michigan connecting
pipes have been added for some time, but the prac-
tice did not become universal. It is not difficult to
save the vapors from the brick kilns, all that is
necessary being to lead the vapors through a con-
denser by means of a suitable pipe. Different meth-
ods of distilling with the object of saving the vapors
will be taken up in the next chapter.

. I . il I . I . I . I , I , I

rn ' i ' i ' i i I . i i

FIG 7 RECTANGULAR BRICK KILN.

CHAPTER IV.

APPARATUS NECESSARY FOR DESTRUCTIVE DISTILLATION.

As has been previously stated, the necessary ap-
paratus for destructive distillation consists of a
retort, arm or connecting pipe, condenser and re-
ceiver. The earliest forms of retorts were prob-
ably the brick kiln. This form is to be distin-
guished from the iron retort in that air has limited
access to it, whereas an iron retort is usually a
closed vessel, being as air-tight as possible.

In Sweden the brick kiln was modified from
those previously described, when the advisability
of saving the vapors became of sufficient impor-
tance. The connecting pipe made a definite outlet
for the products of combustion and a means was
soon devised to regulate the supply of air. The
Swedish oven, so-called, which was thus evolved,
took the form as shown in Fig. 8. This is a hemis-
pherical shaped kiln or oven with an opening at
the top A with cover B by means of which the wood
can be dropped in. At C is a door serving the
double purpose of allowing the wood to pass in
and as an opening for drawing out the char-
coal. At D is another door controlling the air
supply which passes along the passageway E to
the grate F upon which the wood is placed. The
heat' for charring is supplied by the combustion
of a part of the wood in the oven, the vapors and
gases from the combustion passing through the
pipe G to the condenser. The size of the grate
can be varied to suit circumstances. As shown,
this oven takes a great many bricks, but it can
be made of less thickness; the extended doorway
at C can be omitted and the door placed directly
in the wall.

In this country in the Pierce process ovens the
shape of a brick kiln are employed. The uncon-
densable gases formed are led under the kiln and
burned with just enough air for combustion and
the heated gas is passed directly through . the
spaces between the wood in the kiln. This proc-
ess will be described later.

An attempt was made by Hahnemann to heat
the wood from the top of a brick kiln with a cylin-
drical shaft in the middle with openings at the
bottom so that the gases of combustion could pass
down through the wood, and by following the shaft
escape at the top into the air. A pipe at the bottom
v/as supposed to carry off the vapors. It can be
readily seen that the light vapors from the distilla-
tion would also escape at the top.

A modification of the bee-hive form was also
constructed. This had an inner cone for the wood
and the space between the two walls was used as
a furnace to heat the inner wall. The products of
the distillation passed out at the bottom. The
idea was a good one, but the furnace is not of the
best form to get satisfactory results from the fuel.

To heat the wood in a retort, and at the same
time not have the flame from the fire to touch it,
Reichenbach devised an oven consisting of a rect-
angular brick chamber made as air-tight as pos-
sible, and mounted with suitable doors for the ad-
mission of the wood. The furnace gases were then
passed through the chamber by means of large
closed pipes. These pipes becoming red hot, the
heat was communicated to the wood and the con-
tents of the oven distilled. The vapors and tar
formed were taken off at the bottom.

It is evident that ovens have many disadvan-
tages as a means of carbonizing wood for the re-
covery of the liquid products of distillation. As
the desirability of excluding the furnace gases be-
came apparent, apparatus was devised that would
more readily transmit heat. Cast-iron was resort-
ed to, then clay, and then wrought iron and steel.
At the present time most retorts are made of
boiler plate, although some use cast-iron and a few
clay. A clay retort does not readily burn through,
but it is difficult to keep them tight, as they are
so apt to crack, thus causing them to leak when
under pressure. Cast-iron retorts are made thick

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

in order to have strength and have an advan-
tage over wrought-iron in that they do not readily
burn through. They are also liable to crack, and
when the crack is large a disastrous explosion will
ensue; also they cannot be repaired easily.

A boiler plate retort offers many advantages in
that being thinner, the heat is more readily trans-
mitted, and although they may sometimes crack
from unequal expansion and contraction, and are
sure to burn through sooner or later, still they
can be easily repaired by patching either with a
bolt patch with gasket or preferably by riveting.

Clay retorts are generally of one form, the
Q shape of the coal gas retort, and are used
in a similar manner. Cast-iron retorts are usually
simple in shape and are like some forms of ver-
tical and horizontal steel retorts. Wrought iron or

steel retorts assume various shapes; some are
rectangular boxes, some are boiler shaped cylin-
ders and some are of irregular shapes.

Ovens or boxes are not used in the pine wood
distillation, but could be. These ovens are set
in pairs in brickwork and are provided with large
doors at one end and three or more delivery pipes
at the side of each oven. They are usually 27
feet long, 6 feet wide and 7 feet high inside, and
rails are laid upon the floor of the oven by which
steel cars loaded with cord wood can be run in.
These cars hold 2% cords of wood, and an oven
of this size will hold two cars. Some ovens are .
48 to 50 feet long and capable of receiving four
cars at one charge. These ovens are much used
in localities where there is natural gas for fuel.

The pine wood distiller has had more experience

FIG 8 SWEDISH OVBN.
A Air opening.
H Cover.
O Door.

D Air supply door.
E Passage way.
F Grate .
(J Pipe to condenser.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

with cylindrical iron retorts. These are made of
all shapes and sizes, varying more to obtain patent
than for practical utility.

The size of retort for turpentine distillation
seems to be an unsettled controversy. Some claim
small retorts are more efficient and some claim
that large ones are better. In reality much de-
pends upon the method of working and the prod-
ucts sought. One thing is certain, and that is
that a large retort cannot be heated in the middle
as easily as a small one when the heat is applied
by external firing. Wood is a non-conductor of
heat, and if the retort is well filled, as it should
be to save space, the wood near the shell of the
retort is bound to be burned before that in the
middle has been thoroughly charred. This was
one reason why Reichenbach put pipes in his kiln
as mentioned before, so that the heat could be
more evenly distributed. To offset this apparent
disadvantage, users of large retorts try to make
use of the radiating power of heated brick. This
is exemplified by the working of a baker's oven,
in making bread, the radiated heat from the vault-
ed arch concentrating at a common center makes
the heat in the middle greater than it otherwise
would be, thus the inner part of the loaf is cooked
without burning the outside.

With ordinary firing of a retort only portions of
a shell are heated to the same degree, but with
radiated heat the temperature is kept more even.
Although a large retort sems to be a disadvantage
when fired by a direct heat, such cannot be the
case in the steam process for extracting turpentine
where steam alone is used. Here the steam can
come in direct contact with all of the wood alike;
in fact, it can be placed in the middle if need be.
In this process, then, the only limit to the size of
the retort need be the mechanical drawback inci-
dent to the rapidly filling and discharging when in-
termittent processes are used.

In early practice with retorts they were made of
such a size as to allow the contents to be thor-
oughly charred in twelve hours with the necessary
conditions for yielding the nr?3t products. Thus
we find retorts 5% to Gy 2 fee: long with a diam-

eter of 2}4 to 3^ feet for ho.-izontal retorts and
for vertical ones a diameter of 4 to 5 feet and a
height of 7i/ 2 feet.

Gradually the size has been increased until now
we have them of such a size that they can b&
charred and emptied in 24 hours.

Retorts used in the hardwood industry, and now
used with some success with pine, are made about
9 feet long and about 50 inches in diameter and
are provided with tightly fitting doors and an out-
let pipe of about 15 inches for the vapors They
are sometimes set in pairs, sometimes single and
sometimes not protected from the direct flame,
but should be, as they will not burn out so readily
nor buckle so easily. These retorts hold less than
a cord, so in the pine wood distillation it is better
to increase the diameter about 6 inches so that
they will hold a full cord. Cars are seldom used
on retorts of this size, as they cut down the space.
The thickness of the retort varies with the size,
a one cord retort being % to y 2 inches thick. Ver-
tical retorts ate built about this same size.

Other sizes are to be found, though, in the pine
wood distilleries, varying from 3 to 9 feet in di-
ameter and 5 to 30 feet long.

In designing a retort there are certain things
to be taken into consideration when external heat
is applied. There is no perfect retort for wood
distillation, nor can there be, for such a retort
would require that every part of the wood should
be heated to the same degree of heat at the same
! time and for the same length of time. If such
a one were constructed it would not be possible
to charge it. One would think that a large cylin-
drical retort of very small diameter would be the
best. Such would be the best as far as heating
the middle is concerned, but we find, unfortunate-
ly, that the vapors evolved are themselves decom-
posed when kept in contact with the hot sides of
a retort, as they would be in passing from one
end to the other. This might be obviated by hav-
ing several openings for vapors to escape, but this
would necessarily increase the cost of construc-
tion. To get the .capacity and at the same time
to avoid having the length too long and the di-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

ameter too great, we find that the compromise
is effected by having the retorts of such a length
that but little decomposition takes place and of
such diameter as to enable the charge to be fin-
ished in a given time.

A horizontal retort is shown in Fig. 9. This
shows a larger size fitted with rails for a car of
wood. Retorts of this class when the wood is to
be destructively distilled, should be made of as
good steel as possible, with a high tensile strength
and with as few sections as possible. The size should
be arranged so as to allow of' its being made of

one end of the retort which fit with corresponding
rings in the doors. By the use of bolts or wedges
the doors can thus be tightly fastened. If the
doors are small they are hung on hinges, but if
large it is necessary to have a wheel on the bot-
tom to support the weight when the door is
opened. Sometimes the doors are counterbalanced
by weights similar to a dry kiln door, and some-
times hoisted by suitable hoisting machinery, such
as engine, winch, crane or crab.

To support a retort in a furnace it is preferable
to keep all the weight away from the brickwork.

OOOOOOOOOOOOOOOOOOOOOOOOOOOOO

FIG. 9.

A Exit pipe to condenser.

B Car stop.

C Ca^t iron ring.

D Supporting rod.

E Lug.

F Steam pipe.

G Track.

commercial sizes of steel. The various sections
cannot be rivetted too carefully, as a defective
rivet is very troublesome, particularly if in a po-
sition that is difficult to get at. If possible, the
various pipes should be so connected that the re-
tort might be turned when it begins to burn. Out-
let pipes should be as large as possible, so as to
allow of the rapid escape of the vapors. Arrange-
ments should be made to allow the placing of a
pyrometer and any necessary gauges. To make the
heads tight cast-iron rings are usually placed in

This can be done conveniently either by hanging
by means of rods from I beams or by using lugs
similar to those found on boilers, and placing iron
pipes or posts under the lugs, in all cases allow-
ing for the expansion of the retort. Whatever
means of support used, any part of the support ex-
posed to the direct action of the fire should- be
made of cast-iron or some material not easily
burned.

A retort furnace should be made of brick and
well lined with fire brick. A furnace suffers great-

THE UTILIZATION OF WOOD WASTE I*Y DISTILLATION.

ly from the continual heating and cooling incident
to distilling. Only the best work of the masons
is suitable for the purpose. The joints should be
made thin and the fire brick should be laid with
a coating only of the best fireclay, that kind from
which brick was made being preferable.

To support the furnace walls a boiler front is
very satisfactory and adds greatly to the appear-
ance. The brickwork in horizontal retort furnaces
that is just above the retort has a tendency to
crack, so the boiler front should extend around
the top of the retort. The walls through and
through should be suitably tied with long rods, an-
chor rods not being as good. A buckstay
placed horizontally above the rear end of the re-
tort and connected with the boiler front with a
long bolt will help the back wall. Furnaces made
with these precautions are found to give but little
trouble. Arrangements can be made, and one
form is the subject of a patent by means of which
small rollers can be placed in the cooler parts of
the brickwork.

The retort can be lowered on these rollers and
turned, thus exposing a new surface to the hottest
part of the fire when one part is burned.

A vertical retort and setting is shown in Fig. 10.
The same rule applies with these as with horizontal
retorts. As the vapors rise they are apt to be de-
composed at the top, as the heat of the furnace
naturally rises. By keeping the bottom cool they
fierve as a ready means of extracting tar, although
a great deal of retort capacity is lost, as the wood
ought not to be placed where the heat cannot thor-
oughly char it. These vertical retorts are much
used in France and have the advantage that they
can be lifted out of the furnace by means of a
crane and a new retort filled with wood placed in
while the other is cooling. Modifications of this
idea are found in the South and West. One plant
at Georgetown, S. C., uses a brick retort and runs
in a basket. On the Pacific coast an iron retort
is used instead of the brick. It is fitted with an
open work basket and this is lowered into the re-
tort, filled with wood, the retort cover bolted on
and the wood distilled and the charcoal immedi-

FIG. 10 VERTICAL RETORT.
A Retort.

B Combustion chamber.
C Ash pit.

aiely lifted into an iron cooler. This saves the
wear and tear on the retort and furnace. The dis-
tilled products go out at the bottom. In some ver-
tical retorts they are made slanting to let the
charcoal slide out at the bottom.

There are several kinds of special retorts, but
most of them deal with sawdust or hogged wood.
There are but three that claim to be continuous in
operation, the remainder being intermittent. One

THE UTILIZATION OP WOOD WASTE BY DISTILLATION.

form, the Bowles patent, is said to be in successful
operation with hardwood sawdust. The object of
a?l seems to be to stir up the wood so that the
steam can play more readily upon the surfaces of
the pieces and also to prevent the formation of
channels. These forms will be described under
PROCESSES.

Charcoal Coolers. These consist of sheet iron
Voxes made for use with those retorts where the
charcoal is taken out hot. They have a form cor-
responding to the use to which they are to be put.
Where cars are used they are pulled out hot and
run into a box of a suitable shape. Where baskets
are used they are drawn into cylinders of similar
size and shaped to the retort. In another form
sheet iron cars are run up to the door of the re-
tort, the door opened and the charcoal quickly
raked out into the car, a cover put on and the
edges luted with clay and the whole wheeled away
to cool.

Connections. The connecting pipes between re-
tort and condenser should be as short as possible
vhere direct connection is made between each re-
tort and a condenser. In some plants several re-
torts are connected 'With one condenser. In these

cases a long main pipe is necessary and some way
must be devised to keep the vapors from one re-
tort getting to the other. This can be done by
means of valves or by a hydraulic seal, such as is
used in the hydraulic main of gas works. The lat-
ter method is much to be preferred, as valves stick
and if large and made out of iron are gradually
eaten by the acetic acid vapors and are not tight.
On account of the destructive action of these va-
pors upon iron it is advisable to use copper which
is little attacked. C^st iron is better than wrought
iron, which should not be used at all. These pipes
should all be large and so arranged as to be easily
cleaned; it is better to get cooling water on them
in some way, as this will prevent the formation of
a deposit of tarry matters that would otherwise
adhere strongly to the pipe. This cooling is very
important when working with wood rich in resin
and tar. The size of these pipes can be determined
by calculating the amount of vapors evolved (see
yields) from the wood in a given time, the vapors
occupying at least 1,000 times more space than the
liquid products. To be safe make it 1,700 times,
which, with the cooling effect of the air or water
on the connecting pipes, will leave room for the

FIG. 11.

A Pipes from retorts.
B Hydraulic seal.
C Hydraulic main.
j> Overflow pipe to receiver.
E Main pipe to condenser.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

rapid exit of the gases. There should not be over
one pound pressure. The pressure being small,
the thickness is only great enough to make the
pipe of sufficient rigidity to stand outside strains.
Of course, in steam pressure turpentine retorts the
thickness must be large enough to stand the strain
from the inside. See Fig. 11 for illustration hy-
draulic main. In addition to the connections be-
tween retorts and condensers it is necessary to
pipe the gas either to a holder or to the furnace.
The gas is separated from the condensed prod-
ucts in the condenser by means of several devices,
the most simple of which is shown in Fig. 12 A.
This consists of nothing but a brass T, the liquid

A Gas to air.

falling and the gas rising being kept from follow-
itg the liquid by means of the goose neck, as
shown. If the pressure became too high the liquor
in the bend might blow out and the gas escape.
Gas valves are sometimes carelessly left closed,
and this blowing out would at once give warning.
Ihe pipe carrying the gas should be made of cop-
per, but as most of the acid is taken out of the
gas other materials are often used, as copper is
very expensive. A wooden pipe would be a very
suitable pipe. By giving the pipe a backward slope
liquid products that might be mechanically carried
along with the gas would fall back. By placing a
box with lime in connection with the pipe the acid

would be caught and the pipe would be free. This
box would have to be cleaned and fresh lime added
from time to time, the acetic acid being saved
where acetate was made regularly. Another form
of separator is shown at B, Fig. 12, and another at
C, Fig. 12. The one at B is used at several places in
the South. In this form the gas escapes from the

A Gas to air.

B Gas to furnace.

C From condenser.

top of the cone-shaped head and the liquor is drawn
off by means of the cocks, through the funnels
shown, connected with pipes leading to tanks
raade to receive the several products of distilla-
t:on, such as turpentine, tar-oil and tar. In the
one at C, used at Lake Charles, La., the end of
the condenser is led under the liquid, thus form-
ing a hydraulic seal to prevent the gases from re-

'THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

turning to the retort, if for any reason the gas
should explode or the retort cool off suddenly.
This causes only a slight back pressure, as the
end of the condenser only dips under the liquid
about three-fourths of an inch. This contrivance
aiso causes a steady flow of condensed products
from the goose-neck outlet.

Sometimes other contrivances are placed in the

FIG. 12-C.
A Gas outlet.
B From condenser.

connecting pipes, such as tar separators, vapor ab-
sorbers and milk of lime receptacles, but the best
practice seems to be to get the product out of the
wood as soon as possible and do the refining after-
wards in more suitably constructed refining ap-
paratus. When the condensed products are not
caught directly in the receivers, a pipe or trough
is used to convey them to the receivers. As a gen-

eral rule, whenever the vapor contains acid, all
pipes and vessels should be made of copper or
wood. We find wooden troughs very extensively
used for conveying the liquors.

Condensers. One of the most important parts
of a wood distilling plant is the condenser. There
are three general forms used, namely, the worm,
tubular and box condensers. In addition to these
fiere are modifications of the three. The efficiency
of a condenser depends upon the amount of cooling
element and the length of time each particle of the
vspors is allowed in contact with the cooling sur-
face. They should be made of copper where there
is acid.

Small tubes offer more surface in proportion to
their cubic contents than large ones, consequently
we find that tubular condensers are made with nu-
merous small tubes rather than with a few large
ones. However, they must not be too small in the
larger sizes of condensers. A worm condenser
raust be made large, in order to take the large vol-
ume of Vapor; as the vapor condenses the pipe can
be made smaller toward the end. These large
pipes increase the cooling surface in this form of
9. condenser, for they must be made just as long
as a small pipe having enough cooling surface, be-
cause the gases and vapors would pass through a
short condenser before the middle current in a
large pipe would have time to strike the cooling
walls and be condensed. It seems to be a rule with
gases and vapors that they cannot be heated or
cooled very rapidly unless they come in contact
with some solid substance, in the above case the
walls of the pipe. For this reason the box form of
a condenser is not very efficient, owing to the large
volume of vapor present in the chamber at one
time in comparison to the cooling surface. The
most efficient condenser costs the most, hence we
find that the other forms are used in preference
on account of original cost only.

The vapors from the distillation of wood are of
such a nature that it is absolutely necessary to
cool them thoroughly, otherwise some of the va-
I'ors will get into the gas pipe and not only tend
to destroy it, but will themselves be lost. Further-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

nwre, it is advisable to cool them quickly so as to
relieve any pressure that might form in the retort.
The more pressure in the retort the more tar. etc.,
will be decomposed, forming permanent gases. In
reality, some form of exhauster ought to be used
in destructive distillation plants, so as to remove
the products of distillation rapidly and thus pre-
vent the decomposition in the retorts. Many plants
are now introducing such apparatus. Any form
of rotary exhauster, such as are used in coal gas
works, would be especially adapted for this purpose.
A condenser for wood distilling comprises in ad-
dition to the worm, etc., a tank of some kind to
contain the condensing water. These tanks can be
made of wood or of tank steel and should be pro-
vided with an inlet pipe at the bottom for cold
water under pressure and with an outlet pipe at
the top to remove the hot water forced over by the
cold water coming from below. In this way the
nearly cooled vapors coming in contact with the
walls of the pipe cooled by this entering cold wa-
ter become completely cooled and at the same
time the hot water at the top being much cooler
than the incoming vapors, also has a cooling effect,
and thus the water is used very effectively. An
iron tank is better, as it is not so apt to leak.

On account of the desirability of cooling the va-
pors quickly those plants using a main line for all
the retorts should make provision for cooling this
pipe with water. The surface of the pipe would
in this way act very effectively in cooling off
the vapors. Furthermore, these main pipes get
very hot and sometimes the heat becomes so great
as to carbonize some of the vapors and a heavy
deposit is formed that is sometimes difficult to
remove and might at times block the pipe. With
water-cooled pipes this would not happen. The
heavy tar vapors would condense in this main
and flow out the overflow pipe shown ia Fig. 11,
and thus reach the receiver. The first part then
of the condensing apparatus should be the hydraul-
ic main when such is used.

In some plants making wood turpentine by th?
destructive distillation method in order to avoid
the bad odor that is so difficult to remove from

the turpentine produced, two sets of condensers
are used. In such cases the only way to direct
the vapors is by means of valves. The connecting
pipe must be cooled and the water surround the
valve or a great deal of trouble will be caused by
the valve sticking generally from the tar, etc., geN
ting on to the threads of the stem. Where the
turpentine is distilled (generally through a small
pipe) a valve is turned off and a larger one leading
to the other condenser is opened and the distilla-
tion is continued. Except for a very particular
grade of goods this method is not to be commend-
ed as it entails an extra expense for a second con-
denser and also for a very large valve which if
made out of brass, as it ought to be, would be
very expensive, and if made of cast iron the threads
of the seat would eventually be eaten out by the
vapor and the valve practically destroyed. If a
Reparation of the distilled products is to be made
it should be made at the end of the condenser sim-
ilar to the method pursued in distilling petroleum;
any small amount of tarry matter in the con-
denser remaining after the distillation could be re-
moved, either by washing or draining, or if mixed
with the first runnings of the next turpentine dis-
tillate it can be sufficiently removed by the refining
process used.

Box Condenser. This form of a condenser is sim-
ply a rectangular receptacle made of copper for
receiving the vapors. It has the necessary inlet
p;pe for the vapors and an outlet pipe for the con-
densed product. It is placed in a wooden or iron
tank containing the condensing water. In the Bil-
finger process this inner chamber is lined with
wood. A reversal of this system might be better
by putting the cooling water inside and the vapors
iu an outer chamber; it would have the advantage
of being cooled some by the outside air, and at
the same time have a little more cooling surface
on the water side. It might be a little more diffi-
cult to construct, but would need less material to
get the same effect if iron were used in its con-
struction. With copper the cost would be much
increased as there would be four extra walls.

Worm. The next simplest condenser is the worm.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

As before stated, one end must be very large in
order to receive the large volume of vapors, also
it occasions them to move more slowly, thus caus-
ing them to remain longer in contact with the
cooling surface. The worm condenser is shown
in Fig. 1 and Fig. 2. To receive wood distillates
all that is necessary is to attach some form of gas
trap or separator, such as shown in Fig. 12, so
as to separate the gas. The tank shown is for the
containing water and should have an inlet pipe at
the bottom for cold water and an overflow pipe
at the top for the hot water to escape. Several
forms of pipe coolers are used in the various indus-
tries. One form is seen in artificial ice factories
where several rows of pipes are connected with
return bends and a perforated pipe above all from
which a stream of water, the entire length of the
pipe, falls upon each pipe in its descent. This
v/ater is cold at the top layer of pipes, but as it
reaches the bottom it becomes quite warm, finally
falling to the floor or ground and running off. In
such an apparatus the liquid or vapors should pre-

ferably come in at the bottom and come out at
the top. Such an apparatus is not good for va-
pors, although suitable for cooling liquids. With
vapors the condensed matter would cause back
pressure unless the vapors came in at the top, in
v;hich latter case they would not be thoroughly
cooled unless a great amount of water was used.

In the gas works we find the pipes placed verti-
cally instead of horizontally and cooled only by
air. Provision is made for the collecting of the
condensed products by means of a partitioned box
at the bottom. In this way the condensed product
falls into the box and the gas passes on to the
next chamber following the pipe, and any other
further condensed product is separated in like
manner until the gas escapes from the condenser.

Another form similar to what was used at a wood
distilling plant at New Orleans was of the style
shown in Fig. 13. This is sometimes called a box
cooler because of its outward shape, but should
Le distinguished from the box condenser before
described. In the distillation of wood various tar-

FIG 13 BOX CONDENSER.
A From retort.
B Water overflow.
C Gas to furnace.
D Water inlet.
E Gas trap.
F Goose-neck discharge.

THE. UTILIZATION OP WOOD WASTE BY DISTILLATION.

ry matters form which sometimes adhere to the
pipe and cannot be washed out. One can easily
understand that an ordinary worm condenser
v.'ould be troublesome if it should have occasion
to block. To avoid this the arrangement shown
iu Fig. 13 is made. First, the pipe leading from
the retort is connected with a T instead of a
direct elbow and one end fitted with a cap or
flanged head that can be removed for cleaning
purposes. Then each return bend is on the out-
side of the box and being flanged to the ends of
the pipe protruding through the box they can
be readily taken off for cleaning purposes.
Of course, proper stuffing boxes should be made
for the ends of the pipe, so that the pipes can ex-
pand and at the same time no water escape where
the pipe goes through the box. As in the worm
condenser the pipes can be gradually made small-

er toward the discharge end. Sometimes the first
pipe is subdivided into two connecting pipes so
as to give the condenser more cooling surface
v.here the vapors first come in contact with it. At
the outlet the usual gas trap should be placed. In-
stead of having the pipes directly under one anoth-
er they can be placed with alternate pipes to one
side and only a little lower, thus making the box
wider and not so deep. It is best to give each
pipe a rather sharp decline so that the condensed
products will readily flow out.

Counter Current Pipe Cooler. Instead of the
pipes being placed in a box as in the above form,
each pipe may be surrounded with a larger size
pipe containing the cooling water. These water
pipes are connected with one anotner at alternate
ends. The return ends are not covered, but remain
exposed as in the box cooler so that they can be

FIG. 14 DOUBLB PIPE COUNTBR CURRENT CONDENSER.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

readily taken off and the pipes cleaned. Where
ncid vapors are condensed the inner pipe should
be of copper, but the outer pipe containing, the
water is usually of iron. Such a cooler is shown.
In Fig. 14 and the connection in Fig. 15.

Tubular Condensers. It has been noticed that
small tubes are more efficient as cooling agents
than large ones in proportion to their carrying
capacity. This is due to the fact that the cooling
surface is actually greater, and also the rapidity
with which the vapors can be brought into con-
tact with the cool surface. A tubular condenser is
rcore complicated, has more chances to leak and
has the further disadvantage that as usually con-

FIG 15.

A Water.

B Condenser pipe.

siructed a large part of the cooling surface is not
brought in contact with the cooling water.

This latter condition is purposely made so that
the tops can be easily removed, but it is easy
enough to cover them with water if need be.

A tubular condenser as used in a steam process
plant is shown in Fig. 16. This form has been in
use in the hardwood distillation for some time.
Other forms are used, modified only to enable
them to be cleaned out better. Interested parties
should obtain the views of the makers.

In making this form of condenser the outer shell
should be made of tank steel and fitted with suit-
able inlet and outlet pipes. The inner part should
be of copper and should be well braced in the
tank and rest upon a small support in order to
allow the water to get under it and cool the bot-
tom chamber. The top is in the form of a dome
end is fitted with a head that can be removed
and tightened on by means of the yoke and wheel
shown. In larger sizes wing nuts could be placed
Rroimd the circumference and thus draw the edges
together. The tubes should be well beaded into a
bronze or brass plate on both ends, these ends
forming the top and bottom respectively of the
lower and upper chambers. The upper chamber
or dome should be fitted with a large opening for
the inlet of the vapors and the bottom chamber
fitted with an outlet for the condensed vapors and
a hand hole (not shown) for cleaning cut pur-
poses. These connections should pass through suit
able stuffing boxes to prevent the water from com-
ing out of the tank. A gas separator should fol-
low the condenser. The upper dome should be of
sufficient size to distribute the vapors as they come
In without causing back pressure and the tubes
should be of sufficient size and number for the
same reason. In fact, it would be better to have
them of greater capacity so that when the vapors
enter if they should be under pressure they would
naturally have a tendency to expand and thus re-
duce the pressure and help relieve the retort. Other
forms of condensers could be used and different
positions might be given those described, a hori-
2ontal tubular condenser being better for con-
densing engines, but usually to cool the vapors
ficm the wood it is better to have them enter at
the top and discharge at. the bottom as is the
case with vertical condensers.

In regard to the size of the various condensers
as a general rule 150 square feet of cooling sur-
face is sufficient for each cord with water at the
usual average temperature found in the South and
the present rate of distilling.

The following points are to be considered in
estimating the size: 1st, the volume of vapors

THE UTILIZATION OF ' WOOD WASTE BY DISTILLATION.

FIG 1C TUBULAR CONDENSER.

A Water inlet.
B To gas trap.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

tc be condensed in a given time. 2nd, the rate
ol speed at which they are flowing. 3rd, the tem-
perature of the cooling water and the kind of ma-
terial of which the cooling surface is made. The
volume of the vapors can be determined by multi-
plying the number of cubic feet of products expect-
ed in a given time by 1700. If 30 cubic feet of
material were distilled in 24 hours then 1 1-4 cubic
feet would be the average distilled in one hour;
this multiplied by 1700 equals 212,500 cubic feet ol
gases or vapors. In addition to this there would be
not over 20,000 cubic feet of gas at 212 Fah., if
the destructive process is used. With this latter
process the temperature reaches 900, consequent-
ly the gas which is produced at that temperature
is equal to over twice the volume at 212, so the
entire volume to be disposed of would be at least
232,000 multiplied by two, or 930,000 feet.

To cool this product no general rule can be made
that would be more than a rough approximate.
With the steam process it is simply a matter of
condensing so much steam at a given temperature
and pressure. The calculation is based on a math-
ematical basis and is estimated by the number of
heat units absorbed by copper surfaces under given
conditions. The temperature, specific heat, specific
gravity, volume, etc., of the vapors must be known,
the temperature of the cooling water at its en-
hance and exit are also necessary factors. 1
might be considered that it would follow the same
rules of cooling water with water, but such is not
the case.

Kent gives it that "whilst 400 to 600 units of heat
are transmitted from water to water through iron
plates per degree of difference of temperature per
hour, air or other dry gas transmits only about 2 to
o units according as the surrounding air is at rest
or in movement. In a locomotive boiler where
radiant heat was brought into play 17 units of
heat were transmitted through the plates of the
fire box per degree of difference of temperature
per square foot per hour.

A more detailed discussion of the heating and
croling of vapors and liquids will be given under

the description of the heating of steam stills and
the cooling of vapors.

The rate of speed of the vapors in reality regu-
lates the volume of the vapors impinging upon a
given surface per hour, so might mean the same as
the first item mentioned. However, as it is neces
sary for the vapors to touch the surface before
being condensed it can be conceived how in ;
large cooling pipe a large amount of vapor could
be in the middle of the pipe without being cooled
and any short sudden pressure would force this
cut uncondensed. For this reason it might be ad-
visable to make them just a little longer than oth-
erwise.

Tiie temperature and amount of cooling water
used also affects the size of the condenser needed.
Where the water is "old tne condenser wouid be
smaller, and where plenty of water is to be had
(heaply it could be used to help a small condenser
by rapid circulation. Where there is such a vast
difference between the vapors and the cooling wa-
ter, water at 212 acts as a cooling agent at the
top of the condenser. It is better to have the
condenser of such a length that at the required
rate of distillation the water will overflow at about
200 Fah. It is cheaper to have a large condenser
than to have to pump water.

The thickness and nature of the metal influences
the efficiency of the condenser. M. Peclet found
that with perfectly clean metal the quantity of heat
transmitted is inversely proportional to the thick-
ness. Many say that it makes no difference what
the thickness is as far as the transmitting of heat
i^ concerned, but that it is only necessary to make
tbe coils or tubes thick enough for strength and
ligidity. Copper pipe 1-16 inch thick is much used
for the purpose in pipes and tubes, but for the large
condensers greater thickness is required and for
tube plates 3-8 inch or more.

In tubular condensers the tubes are about 1^
inches to 2 inches in diameter, and 6 to 10 feet
in length, and from 3-32 to 5-32 thick. In arrang-
ing them in the plates it is necessary to have them
far enough apart so as not to weaken the plate
itself and also to facilitate construction.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

Receivers and Storage Tanks. In the destruc-
tive distillation and in the other processes for ob
taining turpentine and tar from wood some method
must be used to separate the oily matter from the
watery portion. The condensers discharge their
products either directly into a tank of some de-
scription, or into a pipe leading to such a recep-
tacle. When the first distillate from pine wood
comes over the product consists of water and oil
when steam is used and slightly acid water and
oil when destructively distilled. Upon standing
this mass separates in two layers, the oily matter
en top and the water below. All that is necessary
to separate them is to draw off the water from
below or to let the oil overflow. The same rule
applies to the tarry products also, only we find the
acid water often on top. This liquor usually has
to stand a long time before it can be completely
separated so it is desirable to have several tanks
for receiving, allowing the others to settle while
one is filling up.

In the South wooden tanks are not of much ser-
vice for collecting turpentine in any form. As the
oil from the retort contains water it would soften
any glue that might be ired to keep them from
leaking. An iron or eartherware tank is the only

suitable receptacle for the crude turpentine.

For tar and acid iron is not good and wood will
leak, but as the acid products are of comparatively
15ttle value wooden vessels can be used, provided
ihey are furnished with suitable bolts for tighten-
ing the bands on the tank. For discharge cocks
large wooden beer taps are very suitable. Some-
times large pits are made in the ground and the
sides boarded up and pitched. These are all called
settling vats or pits.

All that is necessary in these receptacles is
to have suitable pipes and valves t& draw off the
separated liquors or to pump or blow them out into
the refining apparatus.

It is advisable to have collecting tanks for each
crude product for at least a week's run. This is
especially true with regard to the tarry liquors,
as the longer they are allowed to settle the better
the separation. In this case seven tanks sufficient
to hold a day's run should be used, or better, seven
tanks each twice the capacity of the tar still would
be suitable. By this means the liquor in the first
tank would have settled for seven distilling pe-
riods and the water and acid (both together equal
to about one-half) could be drawn off and the re-
mainder put into the still.

CHAPTER V.

REFINING METHODS.

The crude materials or distillates having been
collected in the receptacles just described, it is nec-
essary to treat them in some manner in order to
make them merchantable.

The crude turpentine consists largely of turpen-
tine oil, resin oil, resin and more or less of the
gummy and extractive matters to be found in wood.
As generally produced, one or two distillations will
sufficiently refine the turpentine and leave it white
and pleasant smelling. However, in some cases
it is better to treat with some kind of alkali, which
will remove the gums before distilling. Some oper-
ators put caustic soda solution directly into the
still, but this is not to be recommended, as a re-

sinate of the alkali is found when resin oil is pres-
ent, and the steam used in refining will decompose
it toward the latter stages of the distillation and
distill it 1 over into the refined oil, and thus make it
gummy and slow drying. If the distillation is
stopped at this point all the turpentine is not dis-
tilled and the yield is less. Lime, when used,
should be put into the still, as it forms a compound
not easily separated from the oil. Although lime
will take out resin and is cheap, it is not very
suitable as a refining agent. It takes a long time
to act and when put in the still direct it causes a
coating on the walls and steam pipes, which is
not only difficult to remove, but makes it necessary

Of-

FIG. 17750 GALLON STEAM HEATED TURPENTINE REFINING STILL.
A Charging bung. B Steam jet.

C Detail of jet. D Vacuum valve.

E Discharge valve. F Exhaust from coil.

G Boiler connection between head and still.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

to use more steam in the closed coil, as the heat
does not penetrate well through the coating. Caus-
tic soda seems to be the best chemical for purify-
ing. A weak solution answers the purpose and
should be thoroughly mixed with the crude oil.
This is best done by stirring with cold compressed
air or by means of any mechanical stirrer used in
the arts. This mixture should be allowed to settle
and the lye drawn off at the bottom as closely as
possible, then water added and the lye washed out
by mixing and settling with the water. The resi-
dual oil should then be pumped into a copper or
iron still and distilled by means of steam. Such a
steam still is shown in Fig. 17. This still is so
arranged that the crude oil can enter at A. A
steam scroll composed of a closed copper pipe is
shown on the bottom; close to it at B is a perforated
cross made of copper pipe and shown in detail
at C. This allows sufficient live steam to enter
to thoroughly stir the contents of the still. Water
is admitted through A at the same opening as the
crude oil. A vacuum valve is placed at D to pre-
vent any collapse by a sudden cooling. At the bot-
tom are two outlets, the one at B for the residue of
the distillation to be discharged, and the one at F
to allow the condensed steam to escape by connec-
tion to a steam trap, or otherwise. To make the
cap or head tight it is bolted onto the still as
shown at G. This is connected with an ordinary
worm condenser or tubular condenser, or the other
forms mentioned. The still is an ordinary 750-
gallon steam still.

In designing a still it can be readily seen that
the greater the diameter the more evaporating sur-
face, consequently we find that some makers of
stills make them of very large diameter and not
very high. On the other hand, with steam stills
some prefer to have the body of the still of the
same height as the diameter. The thickness varies
with the maker; the McMillan Bros. Co., of Mobile,
Ala., make the top of a 2,000-gallon still of No.
12 Stubb's gauge copper, the bottom of No. 10 and
the sides of No. 13. A still of this size furnished
with 100 lineal feet of 2-inch tubing, No. 13 gauge,
with the brass cross shown in Fig. 17, and all the

necessary connections will be supplied for $800 to
$900, according to the number of attachments and
extra work.

When heating stills by steam coils to get the
best effect, the coil must be drained. This is done
by means of a steam trap, an apparatus which holds
the steam back and at the same time allows the
water to escape. As condensed water is forming
along the entire length of the coil the diameter of
the coil should be rather large, so as to be able to
carry the water to the steam trap without letting
the water fill up part of the coil, thus preventing
the full action of the steam. Be sure to have a
steam trap large enough to carry off the water. In
working with a steam trap the water condensed in
the coil under pressure when it escapes, will boil
and cause steam when exposed to the atmospheric
pressure, thus causing one to think that the trap
is leaking steam. The only thing necessary with a
good steam trap is to have it large enough.

The size of the coil and trap "can be determined
beforehand by considering the contents of the still
to be nothing but water. This we can do because
the temperature of a mixture of water and turpen-
tine, such as is usually distilled, does not have a
higher boiling point than does water. Also, the
specific heat of turpentine of a density of .872 sp.
gr. is .472, water being 1, so being less than water,
one would be on the safe side to consider it as
water.

We will not go into the scientific details of the
causes and principles of heating and cooling, but
confine ourselves to a brief consideration of the sub-
ject. The effectiveness of heating liquids by means
of steam in a closed coil depends upon many con-
ditions. The coil should be drained as well as
possible so as to get the full effect of the steam
at the temperature and pressure used. The circu-
lation of the liquid, the thickness of the coil and the
presence or absence of a deposit on the coil affect
the efficiency. The difference in temperature be-
tween steam in the coil and the liquid to be heated
ako affects the time of transmission to a large
extent, the greater the difference the more heat

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

units per degree difference of temperature being
transmitted.

The element of time enters into the considera-
tion of the subject, for no matter how hot the
steam may be it will take some time to heat the
liquid. The time required depends upon the sup-
ply of steam and the rate of transmission is usually
expressed by the number of British thermal units
(B. T. U.) transmitted from the hot side to the
cool side per degree Fahrenheit of temperature
difference per square foot per hour. A B. T. unit
is the heat required to raise one pound of water
1 degree Fah., the standard being the degree from
39.1 degree Fah. to 40.1 degrees Fah.

Experimental work indicates that copper coils are
more effective than those of other metals in com-
mon use, and for these certain experimenters found
250 B. T. units were transmitted per degree Fah.
difference in temperature per square foot per hour
when heating cold water, and M. Peclet found that
tc evaporate at 212 degrees Fah. as many as 935
B. T. units were transmitted per degree of differ-
ence, due probably to the more rapid circulation of
the water. Other experimenters find different'
amounts, one testing steam feed water heaters ob-
serving that 3G8 B. T. U. were transmitted up to
212 degrees Fah., and 6GO B. T. U. at 212 degrees
Fah., probably with a steel coil, although not stated.
Our problem in a still is confined to heating water
(water and oil) by means of steam, hot gases act-
ing differently. If we take a high rate of transmis-
sion our coils would be made small and steam trap
large, and when we came to condensers the worm or
tubes would be small and our water supply large.
If for any reason the coil did not work perfectly
there would be a bad condition of affairs, as one
could not change the coils readily. By taking a low
rate of transmission and one was disappointed in
the results of transmission and it was higher, then
all that would be necessary to do would be to in-
crease the size of the steam trap and to increase
the supply of cooling water to the condensers,
something which can be readily done.

The above experiments on the transmission of
heat were made with clean coils. Those who are

obliged tc use foul coils, as in the case wnen dis-
tilling resinous oils, find that about one-third of the
rate of transmission given above is the proper
working rate. In evaporating sugar solutions
the water from which would be more diffi-
cult to distill than in the case under consideration,
from 265 to 376 B. T. U. are transmitted.

One would be safe in averaging 300 B. T. units
per degree Fah. difference in temperature per
square foot per hour, both for heating the liquor to
the boiling point and distilling. In addition to heat-
ing the water to be distilled the cooling effect of
the air on the surface of the still itself must be
overcome by the heat of the coil in order to force
the vapors high enough in the pipe to where it
bends to the condenser. The influence of the air is
equal to about 1.7327 B. T. units per degree of differ-
ence in temperature (Fah.) between the contents of
the still and the outside air, (the extremes being
taken for each square foot surface per hour when
the still is of copper, and about 1.438 B. T. units for
iron). This includes all the surface of the still and
vapor pipe to the point at which the pipe turns to
the condenser.

On an average one gallon of water per square
foot per hour should be evaporated by an iron coil
and about three gallons by a copper coil, and often
more.

The size of the steam trap is calculated in a re-
verse manner, the cooling effect of the water evap-
orated causes a certain amount of steam to be con-
densed, this being based on the B. T. units. The
steam trap should be more than large enough to
carry away this water.

A concrete example of this calculation can be
made with the 750-gallon still illustrated. Sup-
pose one wishes to distill 500 gallons in ten hours,
what would be the size of the coil and steam trap,
the steam being supplied at 300 degrees Fah. tem-
perature and 53 pounds pressure? Take the weight
of a gallon of water at 8. 34 @ 62 degrees, or better,
perhaps, 8 1-3 pounds. We then have about 4,167
pounds of water to distill. If it takes 1 B. T. U.
to raise one pound of water 1 degree Fah., it would
take 4,167 B. T. units to raise the 4,167 pounds 1

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

degree. If the water was at 60 degrees to bring it
to 212 degrees Fah., or the boiling point, there
would be 152 degrees to raise the 4,167 pounds of
water with 4,167 B. T. units for each degree. This
would equal 4167x152, or 633,384 B. T. units ex-
pended to bring the water to the boiling point. Con-
sidering no pressure (although there may be a lit-
tle), it is necessary to heat further only sufficiently
to evaporate the water. When we evaporate water
the latent heat must be considered and instead of
1 B., T. U. for each pound to raise it one degree
it will be found that each pound of water absorbs
about 966 B. T. units and the temperature doesn't
change. Then to evaporate the water we must
supply in addition to the heat necessary to bring
it to the boiling point 4167x966, or 4,025,322 B. T.
units, which, - together with the 633,384 used in
heating the water makes a total of 4,658,706 B. T.
units to be supplied in ten hours, or 465,871 B. T.
units per hour. (Plus allowance for air cooling.)

The temperature in the coil is 300 degrees Fah.
and the water 60 degrees, the average water 136 de-
grees, a difference of 164 degrees. For each de-
gree, according to previous decision, 300 B. i\ units
are transmitted per square foot per hour, or 164x
300, or 49,200 B. T. units per square foot per hour
under the given conditions. The total to be sup-
plied in one hour, not counting the cooling effect
of the air, is 465,871 B. T. units, so 465,871 divided
ly 49,200 equals about 9.48 or 9} feet, nearly. To
find the size of steam trap it will be found thai
only the latent heat of the steam is used in heating
with a coil using a trap. The latent heat of steam
at 53 pounds or 300 degrees Fah. is about 904 B. T.
units, and to lose 465,871 B. T. units in one hour
it would take 465,871-^904, or about 515 pounds, of
condensed steam per hour. The weight of a gallon
of water at that temperature is about 7.7 pounds,
so the steam trap should have a carrying capacity
of about 67 gallons per hour. It will be noticed that
this amount is almost seven times the number o\
square feet in the coil. The heat in the condensed
water passing through the steam trap should be
utilized, but it never is. To use this heat in the still
the coil would have to be large enough to condense

all the steam to 212 degrees Fah., and not use the
steam trap, a practice that would not succeed well.
It is better to make the trap a size larger. An im-
portant point to consider is the size of the steam
pipe. This should be large enough to supply suffi-
cient steam to heat the coil sufficiently. There
is no use in having plenty of heating surface and
not enough steam.

Further discussion of this matter can not be
given here. It is a question of steam practice
familiar to engineers. Other vapors than steam act
differently, generally the rate of transmission being
much less. Fire gases act slowly, but their action
is also quite well known.

Tar Stills. At this place will be considered
only the stills necessary for removing the light oils
present in the tar without distilling the tar itself.

The crude liquors containing acids and tannin
matters are very injurious to iron, so copper ought
to be used. Some remove the organic compounds
present, which become dark when acted upon by
iron, by treatment before distilling.

Another distinction is made as to whether they
are to be heated by direct fire or not. In the former
case they are made of two shapes, one like a coal
tar or paraffine still, with a diameter about as
great as the height and the bottom concave ex-
tending toward the middle about one-sixth to one-
third of its height, so that the fire will have more
surface; a man-hole is usually provided at the top
and it is also supplied with suitable mountings
for steam pipe and thermometer. The other form is
similar to a horizontal boiler. In both forms the
vapor is carried off at the top similar to the vapors
from a turpentine still and condensed in a similar
manner.

The steam still is the better as it provides a
surer way of controlling the temperature and pre-
vents the tar from being burnt. This should be
made in all particulars like the turpentine still al-
ready described, and if made of copper will prove
tc be very efficient. The size, of course, must be
proportioned to the product, as there is much more
tar formed than turpentine. The heating coil is
only used for heating the water and driving off the

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

oil, the tar not being distilled. These stills should
be placed in such a position that the tar can be
readily drawn off into a tank. A continuous still
for removing the oils from the tar has not been
used, but a simple one could be very easily devised
for use at a plant where there was sufficient crude
material produced.

Wood Oil Still. The oil from the tar still
:an be redistilled in a regular turpentine still. By
making it of iron with a copper head and worm
this oil can be treated with caustic soda or other
chemical, the caustic solution drawn off and the
oil redistilled, making it of a very bright color.
When all the turpentine has not already been re-
moved from the tar products the first distillate of
the redistillation of this oil will be practically white.
Real wood oil should not contain turp, but should be
a mixture of ordinary wood, red oil and various dis-
tillates of rosin or resin found in the wood.

Still Heads. Several attempts have been
made to rectify spirits of turpentine produced from
wood. As ordinarily produced wood turpentine
contains some light oils that it is desirable to re-
move to prevent its drying too rapidly; also a
heavy oil is to be found which is often carried over
with the steam when the distillation is too rapidly
conducted. To insure steady working of the stills
several devices are in use. Two of these are shown
in Fig. 18. In A, instead of a still head like the
one shown in Fig. 17, a small pipe is carried up to
a considerable height before turning to the con-
denser. This pipe offers considerable cooling sur-
face to the air, consequently quite a little fraction-
ating can be done with it. The lighter vapors can
be condensed first; then the turpentine. In B the
long pipe is branched and pipes placed on each,
the lighter vapors passing through the upper one,
and when they are all distilled the valve is closed

FIG. 18 STILI. HEADS.

OF THE

~ i-r-W

THE UTILIZATION OF WOOD WASTE, BY DISTILLATION.

and the vapors pass through the branch to the
other condenser. At C is practically the same thing
as at B, except water is placed around the pipe to
insure its being sufficiently cooled. These methods
are all crude.

In Fig. 19 is a more elaborate head designed to
be placed on a retort condenser; the proper place
for it, however, would be on a still.

It consists of a tank A filled with water by means
of pipe K overflowing through pipe R. The water
is allowed to enter between the plates C. B. on both

sides, H being merely a support. Each section is
cone-shaped and T is a band running around the
sides of each section so as to enclose the top and
bottom of the vessel and forms a chamber for the
vapors, thus enabling them to come in contact with
the cool walls, B and C. Between the walls B and C
is a plate D, held at one side by the support shown,
and this prevents the vapors from rushing directly
out through P, thus acting as a baffle plate to the
vapors.

The operation is as follows: The vapors enter

FIG. 19 HEGE'S PATENT HEAD.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

at U, pass up P, strike the baffle D and roll back
under the edges of D, which are open, and then
continue above D until they hit the next P, and
so on. C being on an incline any vapors con-
densed on surfaces C, D and B, cannot fall back
through pipe P, into the still, but follow down
N. As originally designed "no valve was shown
at N, but there should be one there and it should
remain closed until that portion of the apparatus
reaches the proper temperature. In this way any
light oils condensed when still is first started in-
stead of running out at S in first section to tank
intended for heavy oils, the increasing heat would
again vaporize this condensed matter and event-
ually put it into the section wherein it belongs.

To determine the proper temperatures a ther-
mometer should be placed before the valve N in
each section. Any vapors that do not condense are
carried away at M. This apparatus has one very
bad feature in that the cold water comes in at
the top and the hot water is forced out at the bot-
tom. It might be better to invert the condenser
and have U connected with the still just the same
and have a Q on the connecting pipe.

A form similar to the above described condenser
is used, which permits the condensed vapors to
fall back into the still. No water is used and tem-
perature regulated so that only the light oils pass
through the head and are condensed. After the
light oils pass over a valve leading to this still
tiead is closed, another valve opened leading to a
worm condenser and the distillation carried on in
the usual manner.

If, by the use of a still head, the bad odor in the
turpentine when it is mixed with tar can be re-
moved, as it is done to a large extent by one com-
pany, then the regular hardwood method of dis-
tillation is the best way of handling the distilla-
tion of wood. However, even the best refiners us-
ing that process leave a trace of disagreeable odor
and a light cast to the oil.

Alcohol Stills and Acetate Pans. The wood al-
cohol from pine wood is seldom recovered, as the
yield is too small. The yield of acetic acid in the
condensed liquor is also much less than with hard-

wood. In Germany alcohol is made. Generally
three stills are required to make the refined alco-
hol. The first one separates the alcohol and the
wood vinegar, the second for the treatment
with lime, and the third for rectifying. As
carried on in the wood alcohol plants in the
North this is as far as the distillation goes, the
further rectification being done at refining plants
in special column stills.

The acetate pans are usually flat sheet iron pans,
like salt pans, and heated with the waste gases
and by steam. The mixture is stirred to keep
from burning the acetate and thus decomposing
it into the carbonate. A more detailed descrip-
tion of this process will be given in describing a
German process.

Condensers. Under this head there is nothing
different to describe than from those connected to
the retort. In refining it is not so necessary to
make arrangements for cleaning as the oil has a
tendency to act as a cleansing agent itself, and as
no tar should be allowed in the condenser, it is an
easy matter to keep it clean.

But the sizes of condensers has been left for
consideration at this place. With surface condens-
ers on condensing engines one square foot of
heating surface is allowed for every 10.6 Ibs. of
steam condensed. This leaves the water at about
120 Fah., the temperature of the hot well. In dis-
tilling turpentine it is necessary to bring the con-
densed material to as low a temperature as pos-
sible, in the summer time to at least 100 Fah.
Then in the case of the engine condenser the ex-
hausts enter under some pressure, whereas in dis-
tilling very little pressure is developed. Again, it
is known that hot gases, such as come from a
retort, do not transmit heat to water as readily as
does steam, so a suitable formula must be found
to suit the case. In the condenser the cooling sur-
face should be as great, or greater, than the sur-
face of the coil in the still and should be able to
condense all the vapors that the still distills. No
allowance can be made for the coating on the coil
in the still, as a coating also forms in time on
the condenser surface.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

It can be considered then that the copper sur-
face of the condenser can transmit the same num-
ber of B. T. units as the coil in the still per square
foot. This was taken at 300 for each degree Fah.
difference in temperature per hour.

Continuing the example given unaer stills, how
many square feet of condenser surface will be nec-
essary to condense 500 gallons of water in ten
hours with the cooling water at 60? The differ-
ence in temperature between the vapors and the
mean of the water is 212-130 or 82 and the num-
ber of units transmitted per degree 300, and for
82 degrees 24,600 per square foot per hour. The
number of pounds of vapor in ten hours was 4,167.
To' cool it the latent heat would be 966 B. T. units,
and the cooling from 212 to 60 equals 152 B. T.
units, or a total of 1,118 B. T. units per Ib. and for
the whole amount 4,167x1,118=4,658,706 B. T. U.
to be cooled in ten hours or 465,871 B. T. U. in one
hour, as we found under the first case with stills.
We have then 465,871 B. T. U. per hour and an
absorption of 24,600 per square foot per hour by
the cooling surface so to absorb it all it would take
465,871 divided by 24,600, or about 19 square feet.
This is about twice the heating surface of the
coil in the still, but this ratio varies with the
initial pressure and temperature of the steam, the
higher the temperature the greater the ratio be-
tween the heating surface and the cooling sur-
face.

The whole problem shows that it depends upon
the amount of heat transmitted by the copper in
a given time. In a water heater this rate was only
68 B. T. U., using steel tubes, and in condensing
benzol vapors only 10 B. T. U. were transmitted
per hour per degree difference in temperature
for each square foot of cooling surface. With a tar
still giving final vapors at 637 Fah. only 812 B. T.
U. per hour per square foot of surface were trans-
mitted not for each degree, but altogether.

In a retort condenser where there is such a
large amount of gases other than steam an allow-
ance should be made of a total transmission of only
1,000 B. T. U. per square foot per hour.

Condensing Water. Knowing the square feet of

condenser surface required, multiply by the num-
ber of heat units transmitted per square foot per
hour and this will be the total number of heat
units to be carried away by the water. The num-
ber of heat units has been calculated all along
on the mean temperature of the water and as the
experiments on transmission were made that way
it is advisable to use the mean temperature of the
water in calculating the results on the con-
densers. With the cooling water it is different.
If the water comes in at 60 and goes out at 200
it is evident that 140 B. T. U. are carried out with
each pound of water, irrespective of the time it
takes to get hot. The total heat represented in
B. T. units per hour divided by this difference in
temperature equals the number of pounds of cool-
ing water required per hour. In the above case
there were 465,871-^-140, or 3,328 Ibs. per hour, and
,at 8 1-3 Ibs. per gallon equals about 399 gallons
per hour.

Storage Tanks. By making the first receivers of
condensed retort vapors of considerable size they
help out the storage capacity of a plant. These
receiving tanks have been spoken of before. In ad-
dition to these tanks others are needed for the re-
fined product. In some plants arrangements are
made to have the condensers on one floor of a
building and the storage tanks beneath so that no
pumping is necessary. A pump, though, particu-
larly if brass-lined, is usually cheaper than the ad-
ditional floor. A common iron tank is not suitable
for turpentine, but a good galvanized tank or an
enameled tank are very suitable and hold well. An
enamel made of white lead is sometimes used with
success, but the best is a glass enamel baked on.

Galvanized tanks are made upright with a convex
bottom they are to be preferred. Glass enamel
steel tanks are made in horizontal and vertical
positions, the former are better to save height, and
the latter easier to measure. They are usually
made in sections composed of flanged rings and
these flanged rings bolted together form the tank.
Tanks for tar can be made of ordinary iron. The
first tar tank is one- of about the capacity or twice
the capacity of the tar still. This is used for re-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION,

ceiving and cooling the hot tar from the still.
When cool the tar can be pumped to a large stor-
age tank. This large storage tank should be set
on piers high enough to permit barreling of the
tar. There should be plenty of storage capacity,
as the product is likely to be slow moving.

Shipping and Packages. For turpentine eight-
hooped white oak barrels, holding 52 gallons, are
of the right kind. Some use six hooped oil bar-
rels, but they are more difficult to keep tight.
The hoops should be well driven and the barrels
glued on the inside. This is done by putting about
four or five gallons of hot glue in the bung hole,
inserting a plug and rolling the barrel so that the
glue will touch all the inner surfaces. The plug
is then taken out and the barrel set on a run to
drain. Sometimes it is necessary to glue two or
three times, using about a pound or so of glue per

barrel. If no water is put in with the turp the
barrel will remain tight for some time if not ex-
posed to the sun.

A tank car is better for shipping purposes, as
it will not usually lean, Dut it is not always as
clean. By coating the cleaned surface with shellac
it keeps the oil in good condition. For tar second
hand oil barrels are much used. These should be
thoroughly repaired and coopered and preferably
soaked before putting in the tar. A tar barrel mus
be kept out of the sun or it will surely leak m
summer weather. A picture is here shown (Fig.
20) of a steam and destructive distillation plant,
showing tar barrels ready for shipment and also
tank car. Tar could be shipped in tank cars to
great advantage. Freight on wood distillates is
extremely high in proportion to their value to the
regular naval stores.

FIG. 20 SHIPPING TURPENTINE AND TAR AT A STEAM AND DESTRUCTIVE DISTILLATION PLANT.

CHAPTER VI.

SPECIAL COMBINATIONS OF APPARATUS AS USED IN MODERN PLANTS.

The different pieces of apparatus just described
are used in various combinations according to the
process used in distilling.

These processes may be divided under several
heads, but the best division seems to be into Steam
Processes, Steam and Destructive Distillation and
Destructive Distillation. A fourth division of Spe-
cial Processes might be used to designate those
processes used in destructively distilling saw dust
and those using rotating retorts, also those retorts
which are to be moved from place to place and
those comprised of conveying machinery suitably
enclosed.

No attempt will be made to assign any relative
value to the patents. It has been the custom for
one man to advance an idea and for another to
patent it, so the patent itself will be discussed
only.

In considering these patents, it is advisable to
understand something of the composition of pine
wood and the products of distillation. These will
be found in detail in a special chapter under that
head. Briefly stated, however, the main object of
the steam process is to extract tne turpentine,
while the object of the other processes is to ob-
tain all the products possible so that the wood
may be completely utilized.

Fat wood contains the woody fibre and resins
with other substances. The resin content is more
stable at a high temperature than the woody fibre,
so it is necessary to consider only the temperature
that first attacks the wood itself. Cellulose is af-
fected at 320 Fah., but the temperature could be
raised slightly above that without doing any seri-
ous harm to the products of decomposition and
distillation.' To remove the resin and leave the
woody fibre intact, three or four methods could be
employed. The rosin could be dissolved out by
suitable solvents and the solvent evaporated. This
might possibly be a good way now that denatured

alcohol is promised to be cheap, but requires con-
siderable capital locked up in the solvent. An-
other way would be to melt it out by dry heat,
another by steam heat, another by heating and
squeezing. Extraction and steaming would proba-
bly be the methods that produce the greater yields,
as a residue would be left in the other cases that
could not be removed by the method employed.

In the steam process for removing the oils, the
first plants worked with large pieces of wood which
were afterwards destructively distilled. The steam-
ing process thus employed was re-discovered (?)
in this century and extraction by this means con-
tinued. However, a more important discovery
which influenced the industry more than any pro-
cess of extraction was a means of cheaply com-
minuting the wood. This machine is known as the
"hog." The advent of this machine in the busi-
ness has made possible the extraction of turpen-
tine from chipped wood in only a small portion
of the time previously required.

At first high pressure with steam was used, but
the tendency has been to gradually diminish the
pressure until now ten or fifteen pounds is consid-
ered the proper amount. The author believes a
vacuum is better, accompanied with sufficient
steam heat to start the oils from the wood. Under
atmospheric pressure the oil contained in the resin
will distill in presence of steam at 212 Fah. It
seems to be more a question of volume of steam
rather than pressure. Sufficient volume of steam
should be admitted to rapidly carry over the oil.

An experiment to determine the proper temper-
ature of steam admitted for distillation when the
operation is carried on at 40 Ibs. pressure was
made at the Massachusetts Institute of Technology
by Messrs. Wiggins, Smith and Walker, with the
result "that the optimum conditions for both tur-
pentine and rosin -are an initial temperature of
175 C, followed by steam superheated to 400

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

C." By this method there is a larger amount of
both resin and turpentine produced. "Below 170
C the oil comes over slowly and will ultimately
cease to distill unless the temperature be raised.
If the temperature is run above 200 the yield
is not improved; the turpentine is discolored and
has a burnt odor. The yield of resin appears to
be decreased with the higher heat, due to the fact
that it decomposes and distills over with the
turpentine."

The above applies, of course, when working at
40 Ibs. pressure. It shows, though, that a certain
amount of heat is better than either a higher or
lower temperature, and this amount of heat should
be determined for different pressures. The loss
of resin at high temperatures may be due to
decomposition or to actual distillation. Resin un-
der atmospheric pressure can be distilled with but
little decomposition when in vacuo or by means
of superheated steam. By using steam alone on
the chipped wood turpentine generally distills and
the resin remains in the retort except that which
is carried over with the steam.

When the destructive process is used with or
without steam a process should be selected that
readily removes the turpentine from the wood
without decomposing the fibre, or some process
that has a special method of refining mixed dis-
tillates in a suitable manner. With those drawing
out the turpentine first, the apparatus used should
be one that easily removes the turpentine and
then decomposes the remaining wood at the least
expense for fuel and at the same time with the
least damage to the retort. When the turpentine
is removed the wood is of the same bulk and us-
ually dry and in good condition for destructive
distillation. As the distillation progresses the bulk
of the residue becomes gradually smaller, so those
processes that heat from the top only are at a dis-
advantage, for when the heat snould be greatest
the material distilling is falling away from the heat
instead of towards it as it should. In most cases
this disadvantage could be overcome by having
flues with suitable dampers for directing the fire
gases.

It takes more fuel where the retorts are protect-
ed, also where cars are used. More damage is
caused without protection also with cars as the
shells must be made hotter in the latter case. A
small retort takes more labor than a large one,
but has proportionately more heating surface. The
use of steam is recommended with these processes
under the same conditions as with chipped wood,
only for a longer time.

Steam Processes. Under this head will be com-
prised those processes using steam with or without
pressure for extracting the turpentine. In this
process nothing is obtained but the turpentine, al-
though some utilization of the residue is attempted.
The steam process has several distinct advantages
over the others. Some of them are that the wood
being in a fine state of division the process does
not take but from one to six hours against 24 to
48 by the destructive method. The turpentine pro-
duced is of a more uniform quality, the apparatus
is not destroyed and the residue left after distill-
ing is sufficient for the fuel necessary to furnish
the steam and cooling water. On the other hand,
it has the distinct disadvantage in localities where
charcoal is in demand of not being able to utilize
a poor ouality of wood except where such wood
has but little value, such as sawdust. Where wood
is relatively expensive the steam process will not
draw out enough turpentine to pay for the wood
itself. This must be taken into consideration in
deciding about building a plant.

la reviewing some of the patents on the subject
one finds that the use of steam, superheated and
saturated, with and without pressure, has been pat-
ented since 1865 by Hall and Emery, and the same
was probably in use before that time. Since then
numerous patents have been obtained for practical-
ly the same principle, but with the retort slightly
modified in some particular. As all these steam
methods were followed with destructive distilla-
tion they will be found under that head. Of those
processes which stopped the distillation when the
turpentine was distilled, the one that first attract-
ed much attention was Krug's patent, exploited by
the Standard Turpentine Company, wno located

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

their first plant at Waycross, Ga. An ordinary
hardwood distillation plant was erected with re-
torts having a bumped head to stand the pressure.
Each retort was mounted with a steam gauge and
two valves, one valve leading to a condenser for
turpentine, and the other leading to a condenser
for tar products. The turpentine valve was sim-
ply a relief valve opening at a definite pressure.

FIG. 21. KRUG'S PATENT (PLAN).

The object of the process seemed to be to steam
off the oil and then to destructively distill the
residue if required. Upon trial the troubles of the
earlier investigators were encountered, one great
difficulty arose in the inability of steam even under
pressure to remove all the oil from a block of wood
in the time of distillation. To obviate this the

wood was ground up in a hog and then distilled.
Under these conditions much success was claimed
in extracting the turpentine. Of course, owing to
the fine conditions of the wood, destructive distill-
ation was not to be thought of. Another trouble
with the plant was the difficulty in charging and
discharging the retort with the fine wood. The re-
torts being horizontally placed, it was necessary
to throw the material in by hand. At another
plant constructed by the main company the re-
torts were set vertically, thus enabling them to be
charged by means of a conveyor. This process
was interesting and great credit is due to the pro-
moters. The idea has been copied in many forms,
some using pressure and some not, the most im-
provement being made in the mechanical handling
of the raw material. As to the validity of any of
these patents there must be some doubt.

Fig. 21 shows the retort used in this process
and the mountings. A is the retort with bumped
heads; a is an inlet for steam which, however,
is not usually used, the steam being taken in from
the top at the front end and a perforated coil
placed in the retort. The retort being set in a
brick furnace external heat can be applied with
the steam if necessary. The turpentine valve B3
is an ordinary valve which can be closed when
necessary, while at B2 is the automatic valve to
regulate the pressure. At D the tar vapors can
arise and pass through D2 to the condenser E and
discharge at C3. The valve D2 probably wouldn't
work but once without choking with pitch or coke.
The turpentine vapors after passing B2 pass to the
turpentine condenser C where they would be con-
densed and discharged. Two retorts are connect-
ed with one condenser, as shown. The illustra-
tion represents a plan, the Upper parts of the ap-
paratus being shown.

Another patent along the same lines as the
foregoing is that of Hoskins, shown in Fig. 22.
One of the methods suggested of utilizing hogged
pine wood and saw dust has been to make it into
paper. This patent endeavors to show a method
by means of which the turpentine can be distilled
and the hogged wood remaining in the retort

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

cr digester can be treated with caustic soda to
form wood pulp. In the illustration A represents
the digester made very strong in order to with-
stand heavy pressure. The digester is surrounded
with a steam jacket (a) provided with an inlet
pipe (al) and outlet pipe (a2), a steam tight
charging door (b) near its upper end and a steam
tight discharging or clean-out door (c) at the low-
er end. In the digester chamber is an outer steam
coil (d), having a valved inlet pipe (dl) and outlet

with a valved cold-water-inlet pipe (k) and a water-
outlet pipe (kl).

The turpentine is steamed off and condensed in
the condenser shown. During the operation the
resin collects on the bottom and can be drawn off
at f. Care is taken not to get the wood too hot
and spoil the pulp. After the turpentine has been
extracted, caustic soda of about 1.20 sp. gr. is put
into the digester and the whole heated and the
pressure raised to 75 or 90 Ibs. for six to twelve

FIG. 22. HOSKINS PATENT.

pipe (d2) and an inner perforated steam coil (e)
having a valved inlet pipe (el). Extending through
the cover (c) at the lower end of the digester is
an outlet pipe (f) provided with a valve (fl) and
extending from the top of the digester is an outlet
pipe (g) provided with a valve (gl). Interposed
in the pipe (g) is a pressure gauge (h); the pipe
(g) leads to the upper end of the coil (i) of the
condenser (B). In the outlet pipe (il) of the coil
(i) is a valve (i2) and the condenser is provided

hours, according to the quality and quantity of
the wood treated. The alkaline liquor is drawn
off and treated as in paper mills or destructively
distilled. The wood pulp is blown out and is ready
for further treatment in the paper mill. The qual-
ity of paper made by pine will be spoken of later.
In this process one operation could be made
to do the work of two if the turpentine was taken
off when the wood was being treated with caustic
soda instead of before.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

The next steam process to be considered is that
of Mallonee, different in one important respect
from Krug's, in that it provides a means of stirring
the chipped wood. The process is evidently sim-
ply a modification of Krug's. From the illustration
in Fig. 23 the essential parts are readily to be
seen. The retort is at 1 Fig 1, and is fitted with
a mechanical stirrer operated by means of gear
wheels. At 17 is a manhole for the entrance of
the chipped wood and for cleaning out purposes.
Live steam is introduced through the perforated
shaft of the stirrer and for heating the resin a
closed coil is placed on the bottom. At 16 is a
pipe and valve for drawing off the hot resin and
at 14 a pipe for leading the turpentine to the con-

ued by means of the closed coil for a short while
until the resin settles, when this is drawn off. The
pulp is then run into the still 19 and heated under
pressure of 60 to 100 Ibs. by means of steam or
otherwise, a weak solution of caustic soda being
added to extract the resin. The relief valve opens
with an excess of pressure, allowing the turpen-
tine to escape to the condenser. After the oil has
ceased flowing the pressure is gradually removed
and the contents discharged.

As shown in the illustration, this process does
not present many merits. The stirrer would be
very inefficient if the retort wre nearly full of
wood and at one plant where a similar stirrer was
used they were found to be liable to be destroyed

FIG. 23 MALLONEE'S PROCESS.

denser. The second still shown in Fig. 2 is used
to extract the remaining turpentine and resin from
the wood. This latter is simply a retort with
bumped head furnished with relief valve and
gauge and draw-off pipe similar in nearly all re-
spects to the Krug retort before described.

To use the apparatus the wood mixed with wat-
er is charged into the retort or still through the
manhead shown in Fig. 1; at the same time the
stirrer is put in motion. When sufficiently full
the contents are heated by means of the closed
coil until the water begins to distill (known by the
pipe 14 becoming warm), then live steam is turned
on under low pressure, and the turpentine carried
over and condensed. When the oil ceases to distill
the live steam is shut off and the heating contin-

by the arms being broken off. Using water in
charging the arms can work more freely, but un-
less there was a lot of water in the retort (in
which case much more heat would be required),
channels would form where the arms turned and
the stirring would not be very effective. Also, the
necessity of charging and discharging two retorts
or stills in the manner shown would prove a
great drawback. As is the case with the previous
process, the necessity of the first part of the oper-
ation does not seem apparent.

Another process for the removal of the turpen-
tine vapors from ground wood is that of Hirsch,
shown in Fig. 24. In this process the difficulty of
discharging the horizontal retorts in the Krug and
Mallonee process is done away with. Here the

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

retort or still is set vertical, the wood entering
the door 14, fills the interior and is ready for dis-
tillation. Steam is turned on by means of a per-
forated pipe and the pressure allowed to rise to
60 Ibs., which is indicated by the relief valve 28,
and gauge 29. When the pressure reaches 60 Ibs.,
the large valve 32, is opened and the turpentine
sent to the condenser. When the distillate con-
tains but a small amount of turpentine, the steam
is shut off and the refuse wood drawn out through
the bottom doors. The valve 32, might be a relief
valve the same as in the Krug and Mallonee proc-

difficulty is removed in this process. Unless some
form of rotating retort is discovered which will
give sufficiently greater yields in a given time to
pay for its extra initial cost, this process, or the
various modifications of it, will prove to be the
best for all-round work. Mallonee in his process
claims as one reason for stirring the material that
the yield is greatly increased and the time of opera-
tion lessened. This can be done better with a
stirrer with vertical shaft than with a horizontal
one, but none are entirely satisfactory, as saw
dust is not easily stirred.

FIG. 24-^HIRSCH'S PROCESS.

esses. The advantages and disadvantages of the
apparatus are apparent from the illustration.

There are a great many companies offering ap-
paratus for sale under patents all described simi-
lar to the process which we will now consider.

In the Gardner process we find the best arrange-
ment of any steam process. The whole success of
the steam processes depends upon the mechanical
arrangements for handling the wood. In the above
processes, it has been noticed that the cost of
operating with saw dust or other material giving
light yields, would be too great on account of the
disadvantageous methods of handling the raw ma-
terial. We will see from the illustration how this

Gardner's process is illustrated in Fig. 25. In
practice only one retort is used, the upper one
being found unnecessary. Often a simple bin is
used in its stead.

To operate the conveyor 6, brings the hogged
wood and saw dust and deposits it into the bin,
from whence it falls into the retort 2. All the
openings are then closed and fastened, except the
vapor pipe 11. A false bottom 10, serves to keep
the saw dust from falling into the vapor pipe.
Steam is turned in by means of pipes 14 and 15,
the distilled turpentine passing out at the bottom.
The stirrers 12, are turned to keep the saw dust
from packing. After the oil is extracted the hot-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

torn is dropped, as shown, and the material falls
out in bulk. The residue dries quickly and can
be used for fuel.

The next steam process to be considered is that
of W. W. and T. L. James. The illustration, Fig.
26, shows a rectangular box retort standing on
edge, supplied with steam coils and also perforat-
ed pipes for live steam. The turpentine is ex-

FIG. 25 GARDNER'S PROCESS.

tracted by means of steam under pressure, the
pressure being controlled by relief valve 32.

This form has a bad shape for pressure, and at-
tempts are made to keep the sides from bulging by
means of bolts. It has nearly every conceivable
disadvantage as compared with other steam proc-
esses, and but one slight advantage in that it takes
less cooling water, the condensing being done by

mixing the combined vapors with water by uniting
water pipe 13, with vapor pipe 33. Even then,
an ordinary jet condenser would be a better ar-
rangement.

The McMillan process was devised to supply a
means of rapidly discharging the retort after the
ground wood has been distilled. The arrangement
consists of an iron retort set vertically with an
inner device J, Fig. 27, composed of several sec-
tions, each one of which is separate from the others
and capable of being forced together or opened
by means of the bolts L.

The wood enters through the large valve D, and

FIG. 26 JAMES' PROCESS.

drops into the device J, where it is distilled by
means of steam entering at A, the vapors passing
out at E. At F is a safety valve and at R is a dis-
charge pipe for rosin, tar, etc. After the turpen-
tine has been extracted, the valves are all closed
and the sections of the inner device J, loosened
by means of the bolts L, thus allowing the distilled
residue to fall to the bottom ot the retort. The
discharged gate B is then opened and steam or air
added through A Al, and the residue blown out.
It can be readily seen that as wood swells when
steamed and is difficult to remove from the retort
on that account, such a device would overcome this

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

FIG. 27 MCMILLAN'S PROCESS.

difficulty nicely. However, stirrers should be used
in order to obtain the best results, and with these
the material ought to be so loosened as to easily
fall out of an ordinary retort such as Gardner's.
On this account, such a device is too expensive
for the result's obtained.

STEAM AND DESTRUCTIVE DISTILLATION

AND DESTRUCTIVE DISTILLATION

PLANTS.

There are two methods of destructively distilling
wood, one using steam to take off the turpentine
and the other not using any. Plants designed for
the latter method can be easily changed to the
first form by simply adding a steam pipe, so in
considering these plants they will be classed to-
gether. The use of steam is considered by some
to be injurious to the oil produced and also to in-
crease the time of distilling. However, most
plants get better oil and better results with the use
of steam.

The use of steam followed by destructive distil-
lation, would form an ideal process if it were not
for the great drawback that steam will not take
out all the turpentine from a block or wood with-
out decomposing the woody fiber, except by pro-
longed heating. That it will do so if heated long
enough, has been satisfactorily proven, particularly
in the case of short pieces, such as sawed knots.
If the wood were hogged then steam would take
out the oil readily, as is observed in the steam
process, but this spoils it for charcoal, without
which product the destructive process cannot hope
to pay. Furthermore, saw dust has been found
very difficult to distill destructively until recently.
The fine wood chars near the shell of the retort,
but the heat cannot penetrate to the middle very
easily, even in retorts of small diameter. Special
retorts to be described later overcome the diffi-
culty of distilling,' but the fine charcoal must be
disposed of at a good price in order to make the
process pay. Briquetting may help if the right
kind of bond can be found.

Unless such a process as above described can
be discovered, those plant's now to be considered
must be located near a supply of rich wood and
have a ready market for their charcoal. Bad loca-
tion has been the cause of many a failure. When
well located, though, these processes are much
more valuable than the steam process alone, be-
cause all the valuable products are obtained from

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

wood and only cheap refuse is used for fuel. A
process that can utilize the wood without having
to use part of the prepared material to fire the
furnaces of the plant itself, is the process that
would be the most acceptable. Whether such a
process will ever be discovered it is difficult to
determine. In the steam process the utilization of
the pulp for the manufacture of alcohol, oxalic
acid or possibly cellulose might prove a satisfac-
tory solution of the problem.

As before stated, wood distilling plants operating
on pine wood were in use before 1865. The patent
records mention the devices of Hull and Emery

present position from the middle of the top of the
retort. The retort is shown at A, supplied with
steam through valve e. The turpentine vapors
pass through pipe I, through tank O, containing
hot milk of lime, and cooled in the condenser Y.
The creosote vapors go through K and condense in
R; any heavy tar condensed in pipe K, flowing
down pipe V. When I and K are closed, the un-
condensed gas and heavy vapors formed coming
from pipe H, can pass up this pipe to the worm r,
where the vapors will be condensed while the gas
passes through S, to separator T, to gas main P.
For about three or four hours the retort is heat-

FIG. 28 WHEELER'S PROCESS.

about that time. They distilled without steam,
and with steam at ordinary pressure and heavy
pressure.

A division of the later processes will be made
into those using horizontal retorts and those using
vertical retorts.

Horizontal Retorts.

Wheeler's Process. A process for the extraction
of oils from pine wood was patented in 1870 by
Wheeler, and improvements added, as shown in
Fig. 28.

In this process, the valves i, k and h, were added
to his original idea and the pipe I, changed to its

ed at a very low temperature by means of a low
fire and live steam and the turpentine taken off
through pipe I. The valve i, and the steam valve
are then closed and the retort heated to 230 degrees
Fahrenheit, for about two hours, the vapors now
passing through valve k, and the gas separating
from the condensed liquors at T, going to the
holder P. The receiver being changed, the vapors
formed at 300 degrees to 400 degrees Fah., pass
through the same exit K, and this heating contin-
ues for six hours. The valve h, being opened
and the valve k, closed, the tar and gas flow out
through pipe H, for about an hour or so. As the
retort holds but a cord, this severe heating does

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

not affect it so much as it would if it were larger.
This separation of the vapors will be noticed in
later patents.

Several other patents followed Emery's before
Wheeler's, but they are not of sufficient importance
to describe. Mention has been made of Stanley's
patent. This process was patented later than
Wheeler's and comprised an ordinary distilling ap-
paratus consisting of retort and condenser, with
necessary arrangements for heating. This ap-
paratus was sold to the Spiritine Chemical Com-
pany, who found it convenient to improve accord-

others; the turpentine being taken off at a low tem-
perature, the tar oil next and the tar running out
the back pipe. A modification of this process con-
sists in substituting a bee-hive brick retort in place
of an iron one.

The next process is that of Hansen & Smith.
The retort is known in the hardwood industry as a
double ender, on account of there being a fireplace
at each end. The retort B, Fig. 30, is made about
25 or 26 feet long and holds about six cords of
wood. The wood is run in on cars, as at F, Fig. 1.

To distill the wood a fire is started at both ends

FIG. 29 MESSAU'S PROCESS.

ing to Hansen's patent, which will be described
later.

Messau process, illustrated in Fig. 29, is of in-
terest, as two features are brought in that may
affect later conditions; first a method of super-
heating is shown, then a method of adding air to
the charge.

In the illustration, A is the retort and S the su-
perheater. The retort is of boiler iron and inclined
so that the liquid products can escape at the bot-
tom pipe on the right. The fire does not touch the
bottom; the heat passing by means of suitable flues
so as to heat the contents. To assist the heating,
air is admitted at G. The operation is similar to

of the retort, the flame passing to the partition A,
through the opening g, then winding around the re-
tort, being guided by the partitions bl and b2, and
finally escaping by means of the stack b3, to the
air. The bottom of the retort is protected from
the direct flame by means of the arch al. The
vapors pass out through pipe f, to a suitable con-
denser. After the wood is charred the fires are
put out and the furnace cooled by means of a ven-
tilating fan, shown at H, connected with h of the
furnace, Fig. 1. This apparatus was intended to
produce wood creosote, which was then used for
creosoting lumber.

There are several Koch processes that are in

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

use, plants being built similar to each one. These
plants have nearly all proveu failures for some rea-
son or other. The principal reason seems to be
small yields from the wood used and a poor mar-
ket.

They have two bad features, one is a brick arch
for protecting the retort and the other is the use
of a closed car. Both of these features mean u.
increased cost for fuel. Too much of the heat g\*s
up the chimney during the latter part of the
operation. The arch does protect the retort and is

Fig. 31. The retort A, can be made of any size
and rails laid hear the bottom. The car K, is
filled with wood and rolled into the retort, the door
of which is then closed. A fire is started in the
furnace at D and the flame follows the flue d. until
it reaches the baffle at the end of the retort then
returns by means of arched brick flues E, El, Fig.
8, to the front of the furnace, then instead of unit-
ing under the retort and burning a hole therein,
the flames enter the side walls at g and then rush
back along the sides of the retort to the back flue

FIG. 30 HANSEN & SMITH PROCESS.

of value where large retorts are used and fuel iS
cheap. The car is a rapid way of withdrawing the
charcoal, but those plants using these cars find
that the wood is not evenly heated, the wood in
one part being charred before the turpentine is
extracted from the wood in another part. It may
be that the furnace flues could be proportioned
better and the cars be made of openwork structure,
so that they can be more readily heated. In this
case, a cooler should be used into which the char-
coal could be drawn.

Parts of some of these processes are shown in

h and then down to i, which communicates with
the stack. This furnace seems to answer the pur-
pose very well when properly constructed, but with
oil fuel, the back wall at E has a bad habit of
dropping when the furnace gets hot. This trouble
is not experienced with wood.

As the heating continues, superheated steam is
let in from pipe b, until the turpentine is distilled,
when the steam is shut off and the distilling fin-
ished by the heat of the fire. The vapors leave
the retort at r and follow the pipe to w. This valve
is closed when making turpentine and the valve V

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

open and the oily vapors thus escape through pipe
P, to a condenser. After the turpentine is taken
off, the valve w, is opened and valve V, closed,
the heavy vapors going to p, where part of them
are condensed and the remainder and uncondensable
gases pass through u to a condenser and gas sep-
arator. To prevent a deposit of tarry matter in
the pipe r, it is surrounded by water contained in
the trough W.

Instead of using the pipe as herein shown, the

much trouble. As before stated, it takes consider-
able fuel as now carried on. The use of cars was
practiced in the hardwood industry before this
process was patented, and their use will be noticed
in Hansen's & Smith's process, previously de-
scribed. The subject will be brought up again
later.

It has been stated that in the hardwood indus-
try small retorts are used very successfully for
carbonizing wood. By connecting these retorts
with suitable condensers, they can be used for dis-
tilling pine. One of the most successful de-

FIG. 31 KOCH'S PROCESS.

pipe in practice is lowered to Z, the cross R being
left out. The water jacket is then brought into
connection with the back end of the retort. By
this arrangement the pipe r, is found to remain
free from a heavy deposit of carbon. Often a tar
pipe is placed at the bottom of the front end of
the retort, by means of which the hot tar can be
removed without vaporizing it.

Under proper conditions, with well proportioned
furnaces, this process ought to distil wood without

FIG. 32 BADGLEY'S PROCESS.

structive distillation plants in the South is com-
prised of a series of such retort's.

To protect the brickwork, when two of such re-
torts are set in one furnace, Badgley devised the
apparatus shown in Fig. 32. It consists of a i
shaped bar placed between the retorts and held
in position by bolts m, n, etc., passing through
the furnace to the rear wall. Rollers are placed
at q, q, upon which the retort can be turned if
necessary. Arrangements are also made so that
the swollen retort can be easily withdrawn when
burned through*. The other features of the proc-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

ess are not of particular interest to the pine wood
distiller.

Another arrangement for turning the retorts is
shown in Inderlied's patent, Fig. 33. The rollers
at a and the balls at b b facilitate the turning of
the retort. An arrangement is also made to con-

FIG. 33 INDERLIED'S PROCESS.

trol the fire gases so that they will not accu-
mulate at one place on the retort. No brick pro-
tection is shown, the fire gases arising envelop-
ing the retort and pass out through the ports e e e,
etc., into the flue f and thence to the chimney.
Each of these port holes can be closed by means
of a damper if necessary.

The flange on the vapor pipe is arranged so
that the retort can be given a sixth of a turn

or more at a time. Instead of putting two retorts
in a furnace, as in Badgley's, this method only
allows but one. However, although the furnace
construction costs more with only one retort in a
setting, it is so much more easy to control the
operation when one is used that perhaps tbis ar-
rangement might be best with pine wood.

If large retorts are to be used in pine wood
distillation, the oven form having given satisfac-
tion in the hardwood industry ought to be satis-
factory when distilling pine. Usually these are
heated by natural gas or oil, but Chapman has
designed a furnace shown in Fig. 34 that is in-
tended for saw dust and wood firing. Whether
such are in use or not the author does not know.

The oven is at A set in a double-ended fur-
nace. The bottom is protected by means of the
tile arch E, in which are port holes to allow some
of the fire gases to pass through, the remainder
turning back under the overhanging arch F and
thus enter the space beneath the retort. In this
manner th heat is to be uniformly distributed.
It is more than likely that in practice the flames
coming through e, striking the bottom of the oven,
will burn a hole therein.

The firebox is so constructed that air can be

FIG. 34 CHAPMAN'S PROCESS.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

supplied through c, so as to burn the saw dust
fuel from the top and also to act as a feed hole.

These retorts can be made 50 feet long and
should be supplied with rails upon tbe bottom on
which cars carrying the wood can be rolled. For
pine wood distillation, suitable steam pipes could
be added and the charge distilled in the usual
way. The vapors would pass out through vapor
pipe Al to a suitable condenser. Arrangements
should be made so that the charcoal can be drawn
out hot.

The next process is the device of one who bas
had experience in both hardwood and pine wood
distillation. A plant is now in operation com-

The retort is at A and inclined so that the
products of distillation may pass out at B at the
bottom. This pipe B is set in brickwork and
thus protected from the direct contact of the
flame, but at the same time is kept warm enough-
so that the tar can flow. The furnace construc-
tion differs from the Koch process in that the
flame on its return from the back at El is turned
up at E2 instead of into the wall, as shown
in Fig. 31g. The object sought is to heat
the top of the retort more than the bottom
so that the distillation might begin at the top
and the products of distillation pass out at the
bottom. The idea of taking off the products of

FIG. 35 GILMER'S PROCESS.

prising twenty of such retorts in batteries of five
with a boiler in between. Ten retorts are in line
on one side and ten on the other with the charg-
ing ends on the outside of the square formed.
The vapor pipes are thus between the two series
of retorts. One condenser is used for a series of
retorts for the various grades of oil distilled, the
vapors from each retort being controlled by a
series of valves.

We have in Fig. 35 the illustration of the set-
ting of one of these retorts. This apparatus was
devised after several years' use of the Koch proc-
esses, so a resemblance to them in many respects
may be expected.

distillation at the bottom is a good one and is
practiced largely with vertical retorts, particu-
larly on the Pacific coast. One would think,
though-, that the vapors of turpentine being so
light, they would be better taken off at the top.
Such might be the case, but the proportion of other
products is so much greater and the vapors so
much heavier that it would be easier to take
them all off at the bottom. Furthermore, it would
be necessary to vaporize the tar to drive it through
a high pipe, whereas with a pipe at the bottom it
can be drawn off as a liquid, thus saving fuel.
When the object is to separate the vapors into
fractions as shown, it is not advisable to heat

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

any portion of the retort too strongly, as other-
wise the wood in one part of the retort would be
yielding tar before the wood in another part had
lost all of its turpentine and thus the turpentine
be contaminated with tarry vapors. Other dis-
advantages of heating a retort at the top would
be that it is more difficult to heat the top than
the bottom; a fact well known; and also that in
the later stages, when the most heat is required,
the wood as it decomposes settles to the bottom,
thus getting further and further away from the

pipe from the other retorts of the same series.
In a similar manner when the proper tempera-
ture is reached, valve i is opened and valve h
is closed, and the vapors pass through I to an-
other main pipe. Toward the latter end of the
distillation, the tar flows through valve g. In all
cases, the uncondensable gas is separated at the
end of the condenser. '

The collected crude products are sent to a re-
fining house, where they are specially treated '"afc-^
cording to the kind of product. For this purpose

FIG. 36 BROUGHTON'S PROCESS.

direct heat, and at the last stage, when the most
heat is required, the wood is nearly half the
diameter of the retort, away from the top. It
would seem that a definite uniform heat, pro-
gressing slowly greater in intensity until the
wood is charred, is better than to heat either the
top or the bottom to a different degree; then by
taking off the products of distillation at the bot-
tom the best conditions would be fulfilled with
little decomposition of the resin or vapors.

As the products come over, the light oils pass
up the vapor pipe H and connect with a main

copper stills are used, having about the same
height and diameter and furnished with suitable
steam coils, vapor connections, etc., for distilla-
tion. The turpentine is generally once distilled,
then treated with lime and aerated, then redis-
tilled very slowly so as not to carry over any
coloring matter. The vapor pipes are small and
carried to a considerable height to a condenser,
under which is set a galvanized tank to receive
the distillate. The water is drawn off from time
to time, leaving the oil, which is placed in barrels
for shipping.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

In Broughton's process, Fig. 36, steam is used,
followed by destructive distillation. Here an at-
tempt is made to fractionate the oils direct from
the retort. In many respects it resembles Bil-
finger's process, except th-at a horizontal retort is
used instead of a vertical one. In the illustra-
tion the process looks rather complicated, but in
reality it is very similar to others and can be op-
erated as readily. The refining apparatus is also
shown.

The retort A is set at an incline to the front.

liquor to the heating tank Q, from whence it goes
to the still S through the worm V to receiver W.
To operate, the wood is charged at a, the door
fastened and steam turned on at about 300 de-
grees Fah. to carry off the major portion of tur-
pentine. This continues about six hours, when a
fire is started and the retort heated to a tempera-
ture of 450 to 500 degrees Fah., this part of the
operation also taking about six hours. The steam
is then shut off and the retort gradually heated
to about 800 degrees Fah., or until the wood is

FIG. 37 MALLONEE'S PROCESS Fig. 1.

At a is the charging door. The grates are in the
rear of the furnace, B, one each side at bl Fig. 2.
By the arrangement of the furnace, the direct
flame from the fire cannot affect the retort. But
it is a very poor device for heating, the arrange-
ment shown in Koch's process, Fig. 31, being far
better. The vapor pipe for the light oils, E, con-
nects with F, a contrivance similar to the barrel
shown in Fig. 41 at 25 and serves the same pur-
pose, that of separating, partially, light oils from
heavy oils. J is the condensing tank, K the gas
pipe, L the receiver. O is a pump for pumping the

thoroughly carbonized. The turpentine which
comes over during the first six hours goes through
E. F. H and J, to the receiver L, the heavier oils
going down Fl to G, where they are drawn off.
The turpentine and some creosote that comes off
during the next six hours follow the same course,
the tar oils and some creosote dropping down
Fl to G and the turpentine and some creosote
going to L. The tar formed flows out of the bot-
tom pipe c into the trough C. This comprises the
regular operation for obtaining the crude mate-
rials. Only the turpentine is refined. The oil is

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

separated from the water in the receiver L and
then forced by the pump O to the heater Q, which
acts as a sort of reservoir for the still S. The
oil in Q is heated by a steam coil to about the
boiling point of turpentine and when sufficient
collects in the heater it is drawn through Rl into
the still S, which is heated by a closed coil, T, at
the bottom. The shape of the still as shown is
not of an approved pattern. As the temperature
is raised the turpentine distills, aided by a jet of
steam, through U to the condenser VI to the
receiver W, where it is ready for shipment.

Mallonee's process sometimes uses steam to ex-
tract the turpentine and sometimes not, according
to the operator. There are several processes sug-
gested by the same inventor, the steam process
being already described. The illustration Fig. 37
shows part of two arrangements. Fig. 1 shows a
double-ended retort set in a special furnace so ar-
ranged that the bottom of the retort is not heated
to a high degree.

Starting at 12, Fig. 2, the flame goes back un-
der the arch 12-1 to the connecting flue 17 by
means of which it passes to 16. Following 16 to

FIG. 37 MALLONEE'S PROCESS Fig. 2.

This process offers nothing specially new, but it
brings back the idea of refining in a current of
steam something which is being neglected at
plants of this kind. If by this method of pro-
cedure all the turpentine in the wood can be re-
covered without color or odor, a great advance
has been made over the older processes. It is
doubtful, though, if turpentine containing creosote
can be refined in the manner described and creo-
sote not be found in the distillate.

Fig. 1 it passes upwards through 19, then rear-
wardly through 18, then upwards through 20 into
chamber 21. Here it passes along the sides of the
retort and going through 24 enters the chamber
8 above the retort, from which it passes through
8-1 into the stack 39. The vapors and the tar fall
to the bottom and flow out the pipe 45, while the
gases pass out at 50.

A previous patent is shown in Fig. 3 of the same
illustration. The patent claims state "tbat here-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

tofore the method commonly used consisted in re-
ducing the wood by means of fire acting on the
closed retort containing the wood and then catch-
ing and condensing all the distillate in one bulk
and running it into one receptacle. The contents
of the receptacle were then refined by the use of
an ordinary still." As the Bilfinger process using
vertical retorts was being exploited before this
patent was applied for, it is surprising that it was
not known that the distillates were divided into
several parts by other parties. Koch and Wheeler
did the same thing sixteen years before.

However, the method as used in this process is
worth considering, for a distinct method is de-
scribed which is more definite than some others;

and steam turned into the retort to help carry
the vapors to the condenser. The distillate in-
creases in gravity as the heating progresses and
the condensed matter is allowed to flow through
the cocks, down pipe 5d (Fig. 3), to a receiver
until the sp. gr. reaches 0.92. This cock is
turned off and the distillate allowed to flow
through cock 5-2 down 5c until the sp. gr. reaches-
0.96, then the cock 5-3 is opened and the remainder
of the distillate allowed to flow through 5-3 down
pipe 5b until the wood is thoroughly charred.

FIG. 37 MALLONEE'S PROCESS Fig. 3.

FIG. 37 MALLONEE'S PROCESS Fig. 4.

the refining operations being much more distinc-
tive.

In the illustration 1 represents the retort set in
the furnace 2, steam when used enters at 3a. The
vapors pass through la to the condenser 5 and
thence through the gas trap to the liquor separator
5a. The refining apparatus is shown in Fig. 4 of
the same illustration. The still 6 is of ordinary
construction furnished with steam closed coils 7
and steam jet 9. The light oils pass through valve
19 up pipe 13 about twenty to twenty-five feet,
then turn to the condenser. The turpentine which
distills later is allowed to pass through valve 20,
the condenser valve 19 being closed.

To operate, the wood being in the retort and
the head tightened, fire is started in the furnace

The second part of the operation is briefly de-
scribed. The first two fractions are treated sep-
arately in stills of the construction shown. The
idea is to fractionate the oils. To do this the first
portion of the distillate is allowed to go up pipe
13 (Fig. 4), where the pipe is cooled by water
spray near the top at 21, the excess water being
caught in pan at 23. This has a tendency
to condense the heavy oils and allow only
the light naphtha-like oils to pass over. After
these are taken off caustic soda of about 1.20,
amounting to 5 or 10 per cent of the charge, is
allowed to gradually enter the still. This causes
frothing and when it subsides more naphtha-like
oil is distilled over, then as the turpentine starts
to distill it is turned directly into the condenser

THE UTILIZATION OF WOOD WASTB BY DISTILLATION.

through pipe 18, the valve 19 being closed. More
details will be given under refining methods.

The third fraction is treated similarly to the
otters, except that caustic soda is not added. When
the light oils from this third fraction cease
coming from pipe 19, part of the residue
in the still will pass through pipe 18 to
the condenser when valve 19 is closed. After
this oil ceases to distill, instead of heating with
fire heat to thicken the tar, the residue is dis-
tilled in a current of steam which takes over the
remaining light oils, leaving the tar in the still in
good condition for the market.

In Palmer's process the object Is to obtain tur-
pentine only from short pieces of wood by means
of steam under pressure. Here resort is again had

of car for use for both purposes, a description of
it may as well be given here.

In the illustration, Fig. 38, Fig. 2 represents a
retort, A, fitted with a three rail track upon which
rests two cars. A steam pipe, E, sends steam
through the middle of each car. This pipe is re-
newed by means of the revolvable joint, n, when
the cars are to be taken out. Any excess pressure
of steam escapes through the lever safety valve, b,
taking with it the turpentine vapor as described
in Krug's steam process. By setting the retort in
a proper furnace the wood can be destructively dis-
tilled and the charcoal be drawn out in the cars
and rolled into a suitable air tight cooler, the vola-
tile product escaping in the usual manner.

The special construction of the car is shown in

FIG. 38 PALMER'S PROCESS.

to the use of cars to transport the wood with fa-
cility. Three rail or two rail tracks are used in
the retort upon which the specially constructed
cars are run in. The patent relates particularly to
the use and construction of the cars. Money could
have been saved by investigating other processes
.in use at the time application was made for the
patent. The same idea, better in some respects,
had been in use several years before this patent
was issued. An illustration of such a plant using
cars of this kind for extracting the turpentine by
passing steam through a perforated pipe, extend-
ing through the middle of a perforated car will be
found elsewhere. At this plant the steam treat-
ment was followed by destructive distillation.
As the perforated car is perhaps the best form

detail at Fig. 4. At E is the perforated pipe fitted
at one end with a funnel shaped arrangement, El,
and the other end without the same. By this ar-
rangement when two or more cara are placed in one
retort the end E2 fits in the funnel shaped end of
El of the other car, thus making a loosely con-
nected pipe extending through all the cars. The
framework of the car is made of slats of iron and
the whole covered with wire netting.

It has been found in practice at the steam and
destructive plant, before spoken of, where similar
cars were first 1 used that there are certain features
of construction necessary to make the cars satis-
factory.

They must be made sufficiently rigid tbat the
wheels will not get out of line, two rails are better

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

than three, the perforations in the steam pipe and
in the netting must be very large to keep from
filling up with tar and gum, and in making tar
should be fitted with a device for scraping the bot-
tom of the retort.

In Adams' process an oven with a V-shaped bot-
tom is surrounded on the sides and top with an
iron shell. At one end of the shell is a fireplace
and on the other a brick flue. The space between
the oven and outer shell is for the fire gases to cir-
culate, and by means of partitions these gases are
led rearwardly in a zig-zag manner to the flue with-
out touching the bottom of the oven. The oven is
set horizontally and from various points in the
bottom are tar pipes. At the top of the oven are
several vapor pipes leading to a condenser, and

height ought to make better tar than a horizontal
retort, for the reason that it is not so necessary
to keep the bottom hot in order to completely char
the wood. When tar is vaporized it usually breaks
up into thinner products and leaves a deposit of
coke. By keeping the bottom of the retort cool
this vaporizing of the tar can be prevented to a
large extent. In vertical retorts of small diameter
only a comparatively small surface comprises the
bottom, so for this reason, in spite of the difficulty
of heating, a vertical retort is of value.

Several forms of vertical retorts have been in

FIG. 39 HESSDL'S PROCESS.

one safety pipe connected with the flue for the
escape of gas when there is much pressure in the
oven.

Like all retort's where the heat is not applied to
the bottom, it is difficult to thoroughly char the
wood, so when the distillation is about finished
air is admitted through suitable openings in the
oven, which burns the remaining tar left in the
wood, the products of combustion being carried
through the safety pipe to the flue. The only merit
it possesses is that it is easy to get at the tar
pipes.

Vertical Retorts. Although a horizontally placed
retort is more easily heated, there are many proc-
esses patented which require a vertical retort. A
vertical retort with a diameter much less than its

PIG. 40 ROAKE'S PROCESS.

use in the hardwood industry in Europe for some
time. All these forms seem to have given way
to the. form shown in Fig. 39, known as Hessel's
Thermo-Boiler, or Swedish Thermo-Boiler. This il-
lustration is taken from the Consular reports of
1901, given by Consul-General Mason at Berlin.

A close resemblance to this apparatus will be
seen in American processes patented since that
time. As this form can be readily used for dis-
tilling pine wood, a description will be here given.

The wood is dropped in at Y into the retort A
and the cover placed on. Tp make turpentine a

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

fire is started at a and superheated steam turned
in from pipe e. The turpentine and light oils
pass over through to B, where the creosote falls
to Bl, the light oil following f to the condenser C,
and thence into separate receivers; the gas escap-
ing through E into the air or led to the furnace.
The tar formed falls to the bottom of the retort
and flows out at c into Bl, which acts as a tar pipe
for a series of retorts. The charcoal formed is
drawn out at y or drawn out at a door near the
bottom, b.

The first American process for distilling pine
or other wood by means of vertical retorts that

The next process, that of Bilfinger's. Fig. 41, is
perhaps the most exploited of any of those using
vertical retorts.

The illustration shows the general construction,
3 being the retort, 22 a box condenser, 31 a goose-
neck trap for the gases which escape above the
"roof through pipe 34. The products of condensa-
tion are divided into three grades and each grade
carried into a separate pipe to a storage tank. The
draw-off valves from the condensers leading to
these pipes are shown at 32. The barrel 25 serves
the purpose of Roake's device just described, that
of separating some of the heavier vapors from

FIG. 41 BILFINGER'S PROCESS.

will be considered is that of Roake, Fig. 40. The
process has to do entirely with the removal of the
heavy vapors from the lighter ones by condensa-
tion in a special vessel, B, corresponding to B,
Fig. 39. This vessel is made very large, so that
the vapors entering at the bottom from pfpe Al
move very slowly, thus giving more time for the
heavy vapors to condense and flow down D into
D3, while the light vapors pass through A2 to the
condenser c. The trays n nl are added so as to
present more cooling surface to the vapors. It
can be readily understood that this apparatus
could be used with horizontal retorts.

the lighter ones. In practice a pipe was placed
at the middle of the shell of the retort connect-
ing with the tar pipe, 16, thus making another
separation of the vapors in the retort itself.

The furnace construction and retort with heat-
ing coil are shown also. The retort instead of
being round is oval, and two are set in one fur-
nace, with the fire door between. No grates are
used, as the fires can be better regulated without
them. At the bottom of each retort at 7 is a
man-hole for withdrawing the charred wood. At
Id is a screen to hold back the chips and brok-
en wood, while the tar flows on through pipe 15

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

to the trough 17. In practice conveyors carried
sawed wood to the top of the furnace, from whence
it is put into the retort through manhole 6. After
cnarging the retort the manhead is replaced and
tightened and a fire started in the furnace. In
some plants steam is not used. The temperature
lo kept quite low and very clear, white oil dis-
tills over and it is allowed to flow into its proper
receiver. As the temperature rises a more and
more yellowish product is obtained and in the lat-
ter stages a bad odor and considerable gas, the

A plant of this kind generally consists of ten
or more retorts set in a row and hold about one
cord each. A distillation usually takes 36 hours,
thus allowing each retort to be charged and dis-
tilled four times per week, starting Sunday night
at 12 M. N., and ending Saturday night at 12 M. N.
The different grades of oil thus produced are re-
distilled and are then ready for the market.

Of the many plants erected to use this process
all, or nearly all, have failed. Although like all
other processes, the different by-products can be

FIG. 41 BILFINGER'S PROCBSS.

latter escaping into the air. By closing and open-
ing the proper valves at 32 the different grades of
oil go to their respective receivers. In the mean-
time, most of the resin and tar is discharged at 16
and flows from the trough into a well. The wood
is not thoroughly charred, but the process is
stopped with the making of red wood, or terrified
charcoal. The tar formed by this process is of
very good quality, as it is not contaminated with
the black tar formed during the later stages when
wood is completely charred.

obtained from the wood and of very good quality,
it is not to be expected that a plant making only
turpentine and tar and taking 36 hours to com-
plete the operation, would be as successful as a
steam process which takes only from one to six
hours. As with all destructive distillation proc-
esses, the retorts are damaged to a great extent
by the heat and are found to leak. Furthermore,
a destructive distillation process that does not
make salable charcoal cannot succeed in competi-
tion with a steam process, as the tar produced by

THE UTILIZATION OP WOOD WASTE BY DISTILLATION.

this method is not of sufficient value to warrant
the expense of obtaining it. With charcoal at a
high price, a destructive plant might pay where
a steam plant would not. This would be particu-
larly true in those cases where wood costs more
than the value of the turpentine produced from it.
The failure of the different Bilfinger processes
has had a very depressing influence upon the wood
turpentine business generally, which never has
been very encouraging, anyway, notwithstanding

the steam process, which has proven satisfactory
to him.

There are two Palmer processes using vertical
retorts, the latest one being shown in Fig. 42.
The working of the apparatus can be easily un-
derstood. Starting with the wood in the retort
and the vapor pipe 5d or 5c at the end of the con-
denser open, a medium fire is started and steam
turned in from pipe 12. The vapors of oil and water
rise and pass out through pipe 3, where the tar

FIG. 42 PALMER'S PROCESS.

the booming it has always received each time a
new patent is granted. The owners of the plants
have themselves to blame, for in most cases they
had their choice of better and longer tried proc-
esses.

Processes taking 24 hours or less are now de-
manded, and those processes that cannot fulfill the
conditions should not be considered. One party
who used the Bilfinger process has now a preju-
dice against all destructive processes, considering
them to be total failures. He is an adherent of

oils are supposed to condense at 3a and flow down
pipe 10 and the creosote to condense at 3b and
flow down pipe 11 and the remaining vapor passes
through condenser 4, where part of it is convert-
ed into liquid form and runs down 5c or 5d to the
receivers, 1 or 8, the uncondensed gases escaping
through 5e. One of the receivers, 1 or 8, is used
for the light turpentine oil, which comes over first,
and the other for the heavier oil during the later
stage. Each receiver is supplied with a filter, 7a
and 8a, and also with connections for a supply of

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

warm water. This warm water is used as a re-
fining agent to remove some of the impurities. The
tar flows out at the bottom after the steam has
been cut off and the heat raised, and finds its way
to a sealed trough, 2a. The charcoal is taken out
at la.

This process, although similar to the Bilfinger,
is not as good. The bottom not being well pro-
tected, the tar is overheated, and what is worse,
the tar pipe, 2a, will choke up and burn off if set
as shown. The same drawbacks of the Bilfinger
process relative to the time of distilling apply
equally as well here.

Another process, evidently a modification of Bil-
finger's, is that of Douglas, shown in Fig. 43. Two

lowed to flow through pipe 25 to where it joins
pipes 33, 26 and 27. Any condensed matter can
thus flow down either pipe 33 or 26 into the bar-
rel, while the uncondensed vapors follow pipe 27
to condenser 28, where they are partially con-
densed and flow into a receiver, any uncondensed
gases going up through pipe 31. Pipe 32 carries
out any light tar oil direct to the barrel, any light
vapor and uncondensed gas going up pipe 33
through 27 to the condenser 28, where they are
separated and condensed in the usual manner.
The tar flows out 35 into the trough 36. This proc-
ess also has the drawbacks of the Bilfinger proc-
ess, as previously mentioned.
A more elaborate process for the refining of

FIG. 43 DOUGLAS' PROCESS.

retorts are set in one furnace and connected
with the same series of condensers. In-
stead of passing all the vapors through
one condenser and separating them into
three portions at the tail pipe, a separate con-
denser is used for each light product. In operat-
ing the wood is placed in the retort and a fire
started in the grate. No steam is used, the va-
pors rise on account of the heat and the light
vapors pass out near the top, down pipe 18, over
barrel 25-1, which receives any condensed creosote
flowing down pipe 24. The light vapors pass on
through the condensing coil 19, where they are
condensed. As the heat progresses the heavier
vapors formed do not rise as high, but are al-

the vapors coming from the retort is that of
Clark & Harris. Chemicals are used to fix the im-
purities.

The object of the patent seems to be to protect
the inventors in a process for the extraction of
pine oil. The claims state that pine wood yields
up a small quantity of turpentine as an educt,
whereas the bulk of the light oil is a product of
decomposition coming over when the temperature
reached 240 degrees to 300 degrees Fah. Further-
more, the claims state that the pine oils will not
distil over with a low temperature steam. If this
were true, the modern steam plant using steam at
5 to 10 Ibs. pressure would yield only a small
quantity of turpentine when used with fat pine.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

However, actual practice shows 15 to 16 gallons
of oil to the cord under these conditions, which
is as good a yield as when the temperature is
higher. The discussion of what the products and
educts from pine wood are will be left for another
chapter.

This process is illustrated in Fig. 44. To carry .
out the operation the retort a is filled with pine
or fir wood and heated gradually in any suitable
manner. During the distillation tar is formed and
is best drawn off from the bottom of the retort
as fast as it is formed, the tar pipe, a2, being al-
ways open.

within the condenser d, whereby the temperature
therein can be regulated to prevent condensation
of the pine oil vapors. The open steam pipe el,
also serves to help along the vapors and to clean
out the apparatus when necessary. The condensate
in the condenser d will in actual operation pref-
erably be kept at such level that the live steam
from pipe el will play over its surface. From the
condenser d the vapors pass through the pipe to
condenser fl, where more condensation of heavy
vapors take place. These flow back to d, while
the lighter vapors pass down f2 through the per-
forated pipe f3 into the box g containing milk

FIG. 44 CLARK & HARRIS PROCESS.

The vaporized products of the distillation pass
into the air condenser d, into the bottom of which
the heavy oils, acetic acid, water, etc., precipitate
and from here they can be drawn off through pas-
sage d3. It is advisable, however, to let them
stay a short time in the bottom of the condenser,
in order that the heat of the vapors may evaporate
any pine oils contained therein, which would other-
wise be carried off with the heavy products in case
they were withdrawn immediately. However, the
best way to guard against possible loss of pine oil
through condensation at this point consists in
providing open and closed steam pipes el and d2,

of lime or other forms of alkali, which absorbs the
acetic acid, etc. Any carbonates formed would,
of course, be decomposed by any excess of acetic
acid to form acetates. The unabsorbed vapors
then pass to a similar box or tank i, containing
a solution of caustic soda of preferably 1.21 sp. gr.
This alkali absorbs the heavy oils, forming a solu-
ble disinfectant. The vapors pass up p into the
air condenser r, where the pine oils are con-
densed, while the light, bad-smelling oils pass to
the condenser rl and are liquified. A condenser
pi, is used to further condense any pipe oil vapor
not going beyond r. The gases are tapped by the

THH UTILIZATION OF WOOD WASTE BY DISTILLATION.

U, r3 and q2, and the pump S draws the gases
away from the apparatus by means of pipes, ul
and t2. The charcoal is drawn out at the door XI.
There is not much doubt that this process cUn
produce a clear, white oil during part of the dis-
tilling process, but it would seem that the process
would require a great deal of care in order to make
all parts of the apparatus work together, and also
it appears that it would be necessary to distil
slowly. The industry requires retorts that will
extract the oils rapidly like the steam process
does, so that there will be but little expense for
plant equipment. One retort with the steam proc-

The operation of the device is as follows: The
wood is placed in the retort and heat applied.
The vapors pass through i into the creosote cham-
ber j, where the creosote separates. The light va-
pors pass to the condenser C, and the oil and
water formed collect in D. The oil rises to the
top of the water and overflows into the refining
still, E. Here the usual refining process takes place
by distilling with steam coming from the boiler, G.
The steam and oil vapor liquify in the condenser,
F, and are collected and separated in the usual
manner.

The creosote that separated in j is allowed to

FIG. 45 SIBBITT & McLEAN.

ess will do as much in one hour as with this
process in twelve. It is more economical to have
refining stills, which are very small in comparison
to the amount of oil treated, than to have refin-
ing retorts.

Another process using vertical retorts is that of
Sibbitt & McLean. In addition to distilling the
wood, an apparatus is added to distil the tar.

In the illustration, Fig. 45, A is a retort in which
the wood is distilled. The furnace construction is
of the usual type. At the bottom of the retort
are water pipes, h, for cooling the tar, and a
strainer b4, to keep the dirt and chips out of the
tar pipe.

flow down pipe v into the creosote refining still,
K. Here the creosote is distilled by means of
fire heat and condensed in the usual manner, the
heavy tarry products remaining in the still and
being drawn into w when necessary.

The tar flows down pipe t to a series of con-
densing tanks, I and J, from which the tar can
be run into the tar still, H. Here the light oils are
driven off. Any water remaining in the tar can
be separated and tar sent to the still, M, for fur-
ther treatment. Here the tar itself is distilled,
light oil of tar vaporizing while the pitch and
heavy oil remain in the still from whence they
can be withdrawn.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

The operation of the process can be understood
from the description of the more simple ones al-
ready given. This treatment of the tar would be
found to be very unsatisfactory.

One hears so much about European methods of
distilling resinous woods, that the following Rus-
sian method is described to show that American
processes are as good as European.

The illustration, Fig. 46, shows Friis's process.
The retort is made of iron, with a V-shaped bottom,
surrounded with a brick chamber which contains
the flue gases. The grates are at c at both ends
and the fire gases -are made to travel around the

In Ross & Edwards' process is found a combina-
tion of the old principles of the Swedish oven pre-
viously illustrated, Fig. 8, and the more modern
ideas of fractional condensation of the vapors to
remove the creosote.

In the illustration, Fig. 47, the retort is repre-
sented at 1. The wood is set on the grate, 4, and
ignited and the carbonization carried on by inter-
nal combustion the same as with an ordinary
charcoal kiln. The vapors escape through pipe
6 Fig. 2, down pipe 7 Fig. 3, where they enter the
hydraulic main, 5. This main is sprinkled with
water by means of perforated pipe, 8a. This cool-
ing causes the heavy oils to separate while the
light vapors pass up pipe 9 through 10 Fig. 2, to
chamber 11, where they strike the baffle plate, 13,
and pass under and up the condenser pipe, 15.
The chamber 11 is used to further purify the va-
pors. The gas formed passes out of pipe 19. The

FIG. 46 FRIIS PROCESS.

top and sides by means of partitions. To help heat
the interior of the retort, flues d pass through the
retort at several places.

The tar and resin formed flow through pipes at
the bottom, while the light oils pass through pipe
6 to a series of box condensers, f, fl, etc., surround-
ed by water, the very light vapors being condensed
by the worm condenser 1. The liquid collected in
the various box condensers is drawn into suitable
tanks for storage. The charcoal is drawn out
through suitable openings at the bottom of the re-
tort. The operation of this process is readily un-
derstood by pine wood distillers.

tar is drawn off at 25 and the charcoal removed at
3. With a kiln this latter would probably be of
poor quality.

The writer would suggest that if anyone wishes
to use a kiln heated internally that instead of us-
ing fat wood for fuel, which is actually done in
the above process, it would be better to place a
similar kiln to one side of the one holding the fat
wood. By placing cheap, low yielding wood in this
kiln and connecting it with the one containing the
fat wood the hot gases formed by burning the
wood in the first kiln could be led through- the
wood in the second kiln, thus causing this wood

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

to distill without much loss of valuable products.
Of course, this increases the cost of a plant, but
the saving in yield of products would warrant it.
One great objection to the kiln form is that both
the fire gases and vapors from the wood must pass
through the condenser, wh-ich must necessarily be
made larger and require more cooling water. When
heated from the outside the fire gases go up the
stack.

As a refining method this process can be com-
pared easily with the others previously consid-
ered. The general principles are the same and are
carried out in a similar manner. None of these
retort refining processes, except that of Clark and

FIG. 47 ROSS & EDWARDS PROCESS.

Harris, seem to take into consideration that when
the oil first begins to distill the creosote sepa-
rators being cold, condense considerable turpentine
which usually finds its way to the creosote tank.

Probably the best of the vertical retort processes
is that of Mathieu, Fig. 48. It was devised by a
man of considerable experience in the industry in
this country and in France. A resemblance is noted
to the French process shown at Fig. 10, Chapter IV.

In this method a process is used of quickly
withdrawing the charcoal without waiting for the
furnaces to cool down. At AA, Fig. 48, is repre-
sented a series of retorts made of fire clay or iron.
Covering the top of the retort is the head, B.

The operation is simple. The basket D is filled
with wood and carried over the retort in the man-
ner shown and lowered into the retort. The cover
being placed on, the distillation is proceeded with
in the ordinary manner, the light oils passing out
at b and the tar flowing out at b2.

The illustration shows how, after the wood is
charred, the basket containing the charcoal is
drawn up into the cooler, J, where the air is ex-

FI&.l.

/*">

FIG. 4i MATHIEU'S PROCESS.

eluded. This operation with one cord retorts oc-
cupies less than five minutes. The cooler and its
contents are then placed to one side after the bot-
tom cover has been put on to exclude the air, and
a spray of water from pipe P allowed to flow over
the surface of the cooler, escaping at the overflow
pipe m at the bottom.

This process is readily understood and is compar-
able with those processes using cars in a hori-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

zontal retort. Both processes offer equal advan-
tages. The vertical retort ought to make better
tar, while the horizontal retort ought to be more
easily heated. A horizontal retort has the advan-
tage that its sections are not entirely dependent
upon the rivets to hold them in position, whereas
in a vertical retort when hot there is a tendency
to sheer off the rivets, owing to the weight of the
superimposed sections.
A process used on the Pacific coast to a limited

the center of the pan, through which they fall to
the bottom of the retort. Through this circular
space, which extends through the middle of the
basket, a water pipe is led branching below each
section as at 30-30. These branches are perforated
and serve as a means of quenching the charcoal

FIG. 49 JEWETT PROCESS.

FIG. 50 FIVEASH PROCESS.

extent is that of Jewett, Fig. 49. The principle
is very similar to Matbieu's, but is more compli-
cated. It consists of a vertical retort, 16, pro-
tected at the bottom with fire brick, 9, and a metal-
lic shield, 13, surrounding the upper portions. A
basket is used as in Mathieu's process, but it is
a complicated affair arranged in sections so as
to stand the wood on end. Under each section is
a solid sheet iron pan, 28, to receive the products
of the distillation, and to direct them to a hole in

after the distillation is finished. All the products
of the distillation go out at the bottom and are led
to condensers and tanks as required.

This process, although patented a couple of years
after Mathieu's, is not as good. It is bad practice
to wet charcoal, as it causes it to powder easily.
In practice it will probably be found that the metal-
lic shield will warp and burn out and probably
change the retort so much as to prevent the en-
trance of the basket. Then the basket itself is not

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

as good as the simple one used in Mathieu's proc-
ess. This latter form answers all the requirements
necessary, and with the cooler forms a very satis-
factory combination. The process offers an advan-
tage in that it takes off all the products of distilla-

It is a self-contained form made out of steel.
The retort is at 4 and is heated by burning fuel
placed on the grates, 12. The products of com-
bustion pass upward through the flues, 18. To cool
the bottom, the chamber, 15, is filled with water,
the steam formed passing through 17 into the re-
tort. At the top of the retort is a charging door,
19, for the wood and a discharging door, 20, for
the charcoal. The volatile matters pass out through

FIG. 51 WILLIAMS PROCESS.

FIG. 52 SNYDER'S PROCESS.

tion from the bottom, thus preventing in a measure
any possible overheating.

In the Fiveash process, Fig. 50, an attempt is
again made of heating the contents of the retort by
means of flues. The writer does not believe that
this apparatus is in use, but it may be.

26 to the condenser, the tar flows out at the bot-
tom at 21, while the gas escapes through 22 and 31.
Apparatus of this kind has been tried since Reich-
enbach's time, but for some reason does not give
the satisfaction that it seems it ought. The ac-
tion of dry heat on flues might be compared to the

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

heating of boiler flues when there is no water in
the boiler. In this process one end is protected
to some extent by the water at the lower joints, but
not at the top. It is difficult, also, to draw the
charcoal and fill with wood. If it were not for the
bad effect of the heat on the flues this idea of
heating the middle of the retort would be a good
one.

Another Pacific coast process is that of Will-
iams, Fig. 51. Steam under pressure is used to
carry off the light oils, and the residue distilled
by fire heat.

In the illustration 1 is a steel retort set vertically
in a furnace. The bottom is protected by a shield,

and tar oil vapors pass through, while the tar is
drawn off into a receptacle, 13a, at the bottom.
To regulate the temperature means are provided
for admitting cooling water through pipe 26, the
hot water returning through pipe 25. By opening
the door the charcoal is 'allowed to fall into cooler,
23, which is covered over to exclude the air.

This process seems to have been well devised,
although the necessity of so many perforated steam
and vapor pipes is not so apparent. The arrange-
ment for getting at the bottom of the retort is
especially to be commended, as the tar often
blocks the pipes. The wood, though, must not be
allowed to get down too far or it will not thor-

FIG. 53 COPILOVICH.

18. At the bottom of the retort is a door for re-
moving the charcoal.

The operation of the process is simple. The
wood in short lengths is dropped through open-
ings 2, 2, at the top, and the openings covered.
Steam is turned in through pipe 28 until the de-
sired pressure is reached and the excess steam al-
lowed to escape through valve 32 at the top. The
steam carrying with it the oil vapors passes
through the perforations at 6 before it reaches the
exit valve. After passing the valve the vapors
follow pipe 4 and are condensed in the usual man-
ner. Any resin formed is drawn off from time to
time through the bottom valve. 13. After the light
oils are distilled the steam is turned off and the
wood heated by means of the fire in the furnace.
The vapor valve 30 is opened wide and the creosote

oughly char. In taking the charcoal out from a
large retort it makes it necessary to place the re-
tort and furnaces rather high in order to allow
room for the cooler underneath.

Another process using vertical retorts supplying
means for withdrawing the tar without heating
the bottom is that of Snyder, Fig. 52.

The wood is put in a container, D, enclosed in a
brick furnace. This furnace is heated by electric-
ity or other means, no heat being applied to the
bottom of the retort. The container, or retort, D,
has a perforated bottom so that when the bottom
of the furnace, a, is closed the vapors can pass
through pipe, g, to a condenser. The charcoal is
removed by lowering D on to a suitable car with-
out waiting for the furnace to cool down.

This method doesn't show any advantages over

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

Williams' process, as in the latter all the vapors
can escape at the bottom if desired. The method
of raising and lowering seems to be much more
awkward than putting it in at the top. As to the
effectiveness of electric heaters definite statements
will not be made here. They are rather expensive
in other lines of industry, and it is to be expected
that such would be the case here. However, as with
all the different pine distilling processes, great
claims are made. The statement is made that a
current of a thousand amperes having a potential
of two hundred volts gives satisfactory results for
a retort holding one-half a cord of wood. Of
course, with larger retorts heated from the out-
side, it would take relatively more.

Another process devised to allow the tar to es-
cape without undue heating is that of Copilovich,
exploited for use with Norway pine in Minnesota,
Fig. 53.

The retort 6 is set in a brick furnace. The wood
is put in at the top and a fire started in the furnace.
The light vapors pass through 10 to a creosote
condenser, 11, and the uncondensed vapors pass
to the condenser 13 and thence to the receiver, 15.
The tar and heavy vapors pass out at the bottom,
the tar going to the tank, 16, and the vapors and
gases to condenser, 18. No arrangement seems to
be made for the separation of the gas, so this
would come out with the vapors and enter tanks,
15 and 19, and would be apt to explode if brought
in contact with a flame. The charcoal is with-
drawn through a door at the bottom on the side.

A Swedish process using such a form of retort
was experimented with for a time in Mississippi,
but for some reason a larger plant was not built.

Denny's process provides a vertical retort pro-
tected on the sides with sheet asbestos and on
the bottom with a double bottom containing sand.

In the illustration, Fig. 54, A represents the re-
tort fitted with the usual exits for vapors. The
wood enters through the top door, 5, and the light
vapors pass out through pipe 21 to a suitable con-
denser and the heavy vapors and tar flow out
through the pipe, 20.

The furnace is heated with wood or other fuel

and the flames strike against the asbestos lagging,
5-1, which protects the retort from blistering. The
flues are so arranged that the flames are deflected
from a straight course by means of a baffle, 11,
thus causing the retort to be heated more effective-
ly. To protect the bottom sand is placed in the
space, 14, between plates 12 and 13. The charcoal
produced is drawn out at 18.

There are doubtless many patents now being
applied for that will be issued shortly. Probably
all of them will resemble more or less closely some
of those herein described, hence readily under-
stood.

It will be seen that some of the essential require-

FIG. 54 DENNY'S PROCESS.

ments of processes of these kinds must be, first, a
good furnace constructed to obtain the greatesf
heat from the smallest amount of fuel; second,
proper distribution of the flame so as not to burn
the retort at one place; third, proper position of
the retort so that all the wood contained therein
can be thoroughly charged; fourth, accessibility of
parts for repairs; fifth, good arrangements for
drawing off the tar without choking the pipe or
burning the tar; sixth, rapid removal of the char-
coal produced so as to save the heat of the fur-
nace; seventh, rapid charging of the retort and
quick distilling methods for obtaining good prod-
ucts, and, above all, eighth an absolutely essen-

82 THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

FIG. 55A THE KRUG STEAM PROCESS SHOWING RETORTS.

FIG. 55B THE KRUG STEAM PROCESS, SHOWING CONDENSERS

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

tial condition the production of salable products.

An illustration of a steam process In actual opera-
tion is shown at Fig. 55. The retorts are enclosed
in brickwork so that the residue could be distilled
if required. At Fig. 56 is shown a steam and de-
structive distillation plant, using cars in large re-
torts.

Any form of retort, if it be nothing but a piece
of water or gas pipe closed at both ends with an
exit for vapors, will make oil from resinous woods,
when heated in the proper manner. This is the
reason that there are so many processes. Some
form of retort is designed and erected and dis-
tilled products are obtained in quantity, and the
problem is supposed to be solved. But some of

these processes must be more economical in opera-
tion than others, and an attempt is expected to be
made by the Forest Service of the relative value
of each, and also which if any are sufficiently eco-
nomical. When proper tests are applied a great
many of the processes now being exploited will
disappear, and the sooner the better for interested
parties who might wish to invest.

Special Retorts and Processes.

Some of the processes which are to be described
under the above heading might have been de-
scribed under steam or destructive distillation
processes, but certain features connected with
them make it advisable to consider them separate-

FIG. 56 STEAM AND DESTRUCTIVE PROCESS, USING COOLERS AND CARS.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

ly. This is especially true of rotary and portable
apparatus.

Rotary Processes. As has been stated, wood,
being a non-conductor of heat, it is difficult to heat
the middle of an ordinary retort to the same de-
gree of temperature as the shell. This feature
is more apparent when the wood is in a finely
divided state such as saw dust. Consequently
when the turpentine is extracted in the steam
process, the residue cannot be destructively dis-
tilled in an ordinary retort, as it seems to be ex-
tremely difficult to heat the saw dust sufficiently
to distill it, except at the edges of the retort.

With hardwood saw dust, attempts were made
to distill it with superheated steam, but it took
so much steam to carbonize that the condensed
water diluted the distillate of pyroligneous acid
and wood alcohol so much that the extra evapora-
tion necessary to make acetate, made the process
unprofitable. Steam has the advantage over direct
heat as applied to a large closed retort, in that
it can be applied to the inside while direct heat
is usually limited to the outside, except in a few
cases. The feature of diluting the pyroligneous
acid, which is noticed with the distillation of
hardwood, with steam is not objectionable when
distilling pine wood, as this portion of the distil-
late is usually not saved anyway, and most of
the oils and the tar are nearly insoluble in water
and can thus be separated by gravity. Large
quantities of steam, though, are costly.

A stationary retort ought to cost less than a
rotary one and when working for turpentine alone,
unless the difference in yield in a given time would
pay for the difference in the initial cost, the ro-
tary retort will find no practical use. In the case
of steaming pine wood for turpentine, it is claimed
by those interested that as much as 25 per cent
more turpentine can be obtained in a given time,
and if such proves to be the case, rotary retorts
will probably supersede the stationary ones. At
the present time stationary ones have the field,
although one or two rotary retorts are in opera-
tion and giving, as is claimed, better satisfaction.

In destructive distillation, the rotary retort is

one of the most feasible ways of distilling saw
dust, either hardwood or pine, if such' be neces-
sary. With the latter not much would be gained,
as pine saw dust makes very poor tar and char-
coal.

By using rotary retorts in a proper manner, the
author believes a better utilization of waste wood
can be made, particularly of medium fat knots

W////////////////////////M

FIG. 57 BERRYS' PROCESS.

such as cannot be used in the ordinary steam
process on account of the cost of gathering being
more than the amount received for the turpentine
produced. This is one case where a destructive
process may be better than steam.

As grinding the wood caused such- a great sav-
ing of time in the steam process, so it may be
expected that a great saving of time will be oc-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

casioned when ground wood is destructively dis-
tilled, provided the heat for this purpose can be
as effectively applied as it is by using steam in
the steam process. This is the result expected
with the special saw dust distilling apparatus
herein described, especially the rotary retorts.
All manner of forms of rotary retorts have been
designed so as to cover all possible modifications,
so that although many patents will be applied for
when the success of this form of apparatus is

retort with an arrangement at K for leading off
the vapors to pipe L, the tar formed dropping to
N and the light oils passing up M to the con-
denser Q. A trap at g holds back the gas which
escapes through S to the furnace. The retort is
beated in the ordinary manner as shown. In Fig.
3 is shown a cross section. Here the retort 13
represented at B; and at one end it is connected
with a shaft leading to the pulley D. The other
end is supported by the head G from which a

27 Feed screw.
11 Flue.

FIG. 58 SPURRIER'S PROCESS.

O Exit for vapors.
P E~xit for charcoal.

demonstrated, only a few of them can possibly be
valid.

The rotary retort is supposed to be the product
of the past few years, but it will be noticed by
what follows that several attempts have been
made in this country as well as in Europe to use
such in distilling hardwood aw dust.

The first patent noticed by the author is that of
Berry, Figure 57. This contrivance was devised
to utilize shells of cocoanuts and seeds, etc., and
for wood. The exact arrangement needs descrip-
tion, as the illustration is not so easily understood.
Observing Fig. 1, we have apparently an ordinary

tubular shaft extends into the retort. Turning
on the end of this shaft is the spider frame F
connected with the retort. The head G being
stationary, it is advisable to make a good joint
between the retort and head, otherwise air might
enter or gas escape according to the pressure.
An exhaust is usually used, consequently any gas
drawn in would probably be fire gases, containing
little oxygen, so little damage would be done if
the head is not absolutely tight. A stationary per-
forated pipe H is added in order to quench with
steam or water the charcoal formed.

It will be noticed that K is removable and is

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

placed over a and that e is also removable and
is placed over the opening b. The opening a is
for filling the retort and b for withdrawing char-
coal. The regular operation is the same as for
a stationary retort, except that the retort is slow-
ly turned, thus causing each particle to be evenly
heated.

A more elaborate retort is used in Spurrier's
process, Fig. 58, for distilling hardwood sawdust*.
This consists of two helices, one working inside
of the other so as to send the sawdust in opposite
directions. The retort is heated by fire gases
led by suitable flues around the retort with a
large flue leading through the middle of the re-
tort. Although such a retort might be suitable in
distilling turpentine from pine saw dust, it is

much too expensive in comparison with other
processes. Another process using rotary retorts
is that of Larsen, also used on saw dust. Owing
to the ease with which a slight modification may
be made on an invention and a patent obtained,
the inventor of this process shows six different
modifications of the same principle. Considerable
ingenuity is shown in each modification and a
complete understanding of the conditions of dis-
tilling are implied. Two different forms are indi-
cated; one in which the retorts is encased in brick
work and the other a self-contained form. Only
the two types will be described. Fig. 1 in Fig. 59
represents the retort set in masonry. The retort
is at A and rotates on a a.

The fire gases starting from the grate pass to

///^/////////^^^

FIG 59 LARSEN'S PROCESS.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

the chamber L, thence follow the course of the
arrows through B, then back through K to the
chimney. The distilled vapors escape through R,
which is turned up so as to be above the material
in the retort. The material is dropped through
the brick work above into manhole g (shown at
the bottom) and when charred is drawn out at
the bottom through the manhole g by the action
of the right and left hand screw conveyer S, oper-
ated from the outside at e. The vanes b rotate
with the retort and help spread the material.

The other form shown at Fig. 3, 4 and 5, Fig.
59, is self-contained. The one above could be made

These devices are well designed to overcome
the difficulty of heating the retort; As arranged,
the whole retort revolves, flues and all.

One feature of machine design is the ac-
cessibility of parts for repairs. Unless the above
retorts are very large, one who is acquainted with
the destructive action of heat when wood is dis-
tilled can readily understand that great trouble
might arise from the use of such retorts. Another
difficulty would probably be the warping and
bending of the flues under the effect of the heat.
A further disadvantage is that in destructive distil-
lation, every rivet used is apt to give trouble. In-

FIG. 60 HAKLIDAY'S APPARATUS.

so also by leaving out the surrounding brick. The
action of this is similar in most respects to the
other. The fire gases instead of being in two pipes,
one surrounding the other, are in numerous pipes.
The flame as it arises from the grate is prevented
from entering K, so it goes through the flues C to
a central chamber at the back, from which it is
drawn through pipe K to the chimney. The va-
pors pass through screens set in the back plate
(shown in detail at Fig. 4) and thence through
pipe R. To keep the screens clean a wire brush
e Fig. 4 is used and worked from the outside when
necessary.

stead of there being fewer in this apparatus,
there se'ems to be need of many. If, in the work-
ing of the apparatus, these difficulties do not mani-
fest themselves, we have in these processes, per-
haps, one of the best for the destructive distilla-
tion of saw dust and the like.

An apparatus much used in England and Europe
for distilling hardwood saw dust is the device con-
structed by Halliday.

According to the description of it given by
Hubbard in his "Distillation of Waste Wood," this
process is a continuous one, and consists of a
cylinder with feeding screw; according to the speed

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

with which the screw is driven, the wood can be
exposed for a longer or shorter time to the action
of the heat, and thus a larger yield of acetic acid
is obtained than is possible from the charcoal
mounds. The fact is, however, not to be ascribed
to an especially favorable construction of the ap-
paratus, but exclusively to the form of the raw
material. From small fragments of wood, the dis-
tillate is much more rapidly evolved than from
large billets, and the distillate undergoes much
less decomposition in th-e apparatus. The saw
dust is thrown in the hopper B (Fig. 60).

In this hopper a revolving screw C delivers the
material at an appropriate rate into a horizontal
cylinder. The latter is heated by the furnace A.
A second screw D keeps the material in the retort
in constant motion, and at the same time conveys

it gradually to the other end of the cylinder. The
wood becomes carbonized as it traverses the cylin-
der so that by the time it reaches the further end
it has parted with its volatile products. Two
tubes are connected with this end of the cylinder.
One of these, F, descends into an air-tight closed
cast-iron receiver, or else into a cistern, G, filled
with water; the other, E, carries off the products
of distillation to the condenser, which consists of
tubes surrounded with water. It can be readily
seen that this apparatus with a perforated shaft
for steam could be easily used for distilling pine.
This apparatus has been in use for a long time.

In Viola's apparatus an arrangement is made
to rotate the outer shell of the retort in addition
to the use of a screw conveyor.

In the illustration Fig. 61 is shown one form

FIG. 61 VIOLA PROCESS.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

of this apparatus. Its method of operation is read-
ily understood on account of its similarity to the
Halliday apparatus just described. The raw ma-
terial enters at A, which portion of apparatus is
provided with a stirrer to keep the material from
packing. As the wood drops to chamber D it is
moved along by the screw conveyor to the bottom
end, by which time it should be distilled. The re-
tort shell of this part is rotated in order to help
stir the material. The vapors pass out through
B to a suitable condenser, while the charcoal is
drawn out from time to time by opening the cover
C. This apparatus is continuous.

Another form is used intermittently. The feed
end is omitted and also the screw conveyor. One

fications can be made, such as inclining the re-
tort, extending the heads, changing the location
of the rotating parts, etc., all of which have been
considered in connection with the process as car-
ried out. The illustration shows the form which
is operated under slight pressure, no pressure or
vacuum, according to the nature of the substances
to be distilled. It can be readily seen that such
an apparatus would be of service in other lines of
chemical industry, where distillation, roasting or
drying processes are used.

In the distillation of wood, it could be surround-
ed by a brick furnace and saw dust and hogged
wood distilled by its means. Steam can be admit-
ted to the conveyor shaft as well as at the place

FIG. 62. HARPER'S PROCESS.

end is furnished with a door for the admission of
the wood, which is held in position by a frame,
while it is being distilled. The vapors escape
through B, as is shown. Charcoal is pulled by
means of the frames to C. This opening is ar-
ranged to dip under water like in the Halliday
apparatus. This process seems to be very com-
plicated and does not appear to be as efficient
as the Halliday apparatus, which is far more sim-
ple.

A steam process continuous in action connected
with the saw mill would be very convenient if it
worked automatically and at the same rate as the
saw dust, etc., was supplied. This suggested in
the year 1900 the Harper process, one modification
of which is shown in. Fig. 62. Many other modi-

shown. In distilling rich wood an arrangement is
added which takes off the resin formed. In dis-
tilling under pressure the screw conveyors are
so arranged that no steam can blow through while
feeding and the rotating part properly packed.

The retort as used in accordance with illustra-
tion is filled partly full .by the feed screw A and
the steam either saturated or superheated turned
in. The material moves along the bottom of the
retort on account of the settling action of the
mass. The steam being under low pressure can-
not escape through the conveyor on account of
the mass of material in the feed box and conveyor
trough. A ready outlet for the vapors is furnished
at B, preferably screened to prevent saw dust
from blowing through the pipe.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

The heads of the retort are stationary and only
the shell and the lifting vanes C rotate. A steel
tire is provided for the retort at both ends so that
it will stand the wear of rotating. No weight is
allowed on the driving machinery, the entire load
being carried by the rolls.

By the time the material reaches the rear end,
all the volatile matter is distilled and tbe vanes
catching the material lift it and deposit it upon
the trough of the screw conveyor B, and thus it is

The form of screw conveyor shown in these
forms of apparatus is not very suitable for moving
saw dust, but other forms can be used which are
suitable. With very fat wood the above apparatus
is supplied with a special chain for scraping the
bottom.

For destructive distillation in such a retort in-
stead of heating the shell, a self-contained form
can be used by putting in flues similar to those
used in the Larsen process or the wood can be

FIG. 63 FLEMING'S PROCESS.

carried out and dropped on to a conveyor leading
to the furnaces.

At those plants where turpentine and tar are
mixed and then separated one of these retorts
would answer the purpose. For those who prefer
to distill the turpentine separate from the tar,
two would be necessary, one for the turpentine
and one to destructively distill for the tar. As
used above, the apparatus would be used for saw
dust, which would not pay to distill destructively,
so only the turpentine would be taken off. In this
case the shell should be covered with suitable lag-
ging.

charred in the retort, as illustrated, by means of
superheated steam, thus requiring no brick fur-
nace.

If required, this apparatus can be used station-
ary or intermittently. In the latter case, after the
retort was charged all that would be necessary
would be to stop the feed and discharge screws
until the distillation was ended.

By using hot gases containing no oxygen the oils
can be extracted and the gases passed through a
reheater and used over again. Gas takes up heat
and loses heat rather slowly. Hardwood saw dust
can be distilled with this apparatus.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

All rotary and continuous processes are more
expensive to construct, cannot be worked well on
variable material, and are difficult to make tight
under heavy pressure. However, much pressure
is not now used. They have the advantage of
being made in any length when supported prop-
erly and can thus be made to hold 100 tons or
more, the size being determined by the rate of
distillation.

The next is Fleming's process, shown in Fig. 63.
Not much need be said concerning this process,
as it is so simple in construction that it is ap-
parent from the illustration.

It consists of a rotary retort working intermit-
tently, the ground wood being fed in the manhole
10 at the top and discharged at the bottom through
the same orifice, when the retort is turned.

To operate, steam is turned on through the per-
forated pipe shown and the steam and turpentine
vapors pass through the funnel-shaped mouth of
the pipe 8 to the condenser* the retort being slowly
turned during the operation.

Another form of retort constructed on exactly
the same principles as that above is that of Coe.
It consists of a large steel ball, instead of being
elongated as in Fleming's process. The supports,
manhead, steam and vapor pipes, etc., are adjust-
ed in a similar manner to Fleming's.

A sphere will stand pressure better than a cylin-
der and would be more rigid, but the elongated
form would be heated to better advantage.

One feature noticeable about the process is
that Coe claims a yield of 25 per cent more by
his process than by the stationary steam process,
and attributes it to the stirring of the material
in the retort and tbe breaking up of the ground
wood as it rubs together while rotating.

It can be seen that either of those forms would
not cost much more than a stationary 'one and a
25 per cent extra yield would more than pay the
initial cost. They must be made thicker than the
others in order to stand the strain of suspension
and the weight of tbe wood.

A later process than Fleming's is that of Jack-
son, Fig. 64. As can be readily seen the differ-

ence lies chiefly in turning the retort around so
that it rotates from the sides instead of the ends.
This makes it necessary to change the arrange-
ment of the steam pipes so as to make them
longer.

To operate, the wood is dropped in at B, the
head bolted on and steam turned in. The steam
supply enters the shaft at G, then leaves again at

FIG. 64 JACKSON'S PROCESS.

C and follows a pipe outside the retort and then
enters the retort at J 1. The vapors follow a simi-
lar course, leaving the retort at a point opposite
to J 1 and coming back again to the shaft at D
and passing to a condenser. This arrangement
of steam pipes and vapor pipes is entirely un-
necessary. There is no reason why the steam
could not* continue in the shaft until it entered

THE UTILIZATION OF WOOD WASTE, BY DISTILLATION.

the retort, as in Fleming's process, and tben pipe
to J 1, if necessary.

A patent should have been granted to but one
of these three parties, as the principle of the one
is the same as that of the others.

A great many patents have suggested the ad-
visability of using pine wood pulp for paper-making
after the turpentine is extracted.

The only one ever tried is that of Handford's,
Fig. 65. A plant using this process was built near
a paper mill using yellow pine for making pulp

Al, where the chips are torn into shreds by a
machine called a fiberizer. The material thus
treated falls upon the conveyor H by means of
which it is taken to the top of the rotary digester
B and drops therein through the manhole K. A
stirrer with paddles is on the inside of the digester
which takes the material from the entering end
K to the opposite end, where underneath in a sim-
ilar position to K is another manhole which al-
lows the material to be dropped out of the diges-
ter. The steam enters and the vapors leave the

FIG. 65. HANDFORD'S PROCESS.

by the soda process. It proved unsuccessful for
two reasons chiefly; first, because in using the
lean wood the operation of extracting the turpen-
tine did not pay for itself, and second, the residue
after treatment made a very poor quality of pa-
per.

As will be found later, under Chapter XI, proc-
esses for the preliminary extracting of the tur-
pentine from pine wood when making paper pulp
are not necessary.

Fig. 65 represents a plan of the process. At A
is hog through which the chunks of wood pass to

digester in the same manner as in Fleming's proc-
ess; the steam going in through the shaft from
pipe L at one end and going to the condenser
through pipe E at the other end. A closed con-
veyor is under the digester B and it takes the
discharged material above DD and it is permitted
to fall and pass through heavy steam heated rolls,
which press out the liquid material in the resi-
due; any vapors rising and entering pipe El and
thence going to the condenser. The material that
is discharged from the rolls is then used for paper
making.

THH UTILIZATION OF WOOD WASTE BY DISTILLATION.

On account of the non-success in making paper
from the residue an attempt is now being made
to manufacture straw board from the pulp. There
is no use making turpentine, though, if the ap-
paratus does not extract it cheaply enough; it
would be better to make straw board or pulp di-
rect.

Movable Retorts. Under this head come those
retorts that are so made that they can be easily
taken down and transported from place to place,
thus bringing the retort to the wood rather than
the wood to the retort.

The first process to be mentioned is that of
Dromart, used in France. Here retorts' holding 14

sote in creosoting lumber, and had a bearing more
on the production of creosoting oil than on tur-
pentine, although pine wood was used.

The illustration shows the process sufficiently
to set forth the idea. In Fig. 3, Fig. 66. is repre-
sented a retort set in a furnace for heating. It
is divided into three sections, as shown at e e, the
vapors escape by a, Fig. 5, to a condenser. The
wood is taken in on trucks, as shown, and the
distillation proceeded with in the ordinary man-
ner. One retort is used for distilling and the
other for creosoting.

FIG. 66. SMITH'S PROCESS Fig. 3.

cords are made in sections each section weighing
about 110 pounds. This was used way back in
1830. The iron sections were made to fit each
other so as to make a dome shaped kiln and the
joints luted with clay. There was a chimney at
the top with arrangements for regulating the
draft. The beat was supplied by the carbonizing
of the wood inside, as in an ordinary brick kiln.

The only other process of the kind to be dis-
cussed is that of Smith. Its object was to pro-
vide a suitable portable apparatus for distilling
wood and at the same time be used for creosoting
lumber. This was devised at the time that wood
creosote was used in preference to coal tar creo-

FIG. 66. SMITH'S PROCESS Fig. 5.

A later process combining wood distilling and
creosoting is that of Davis, Fig. 67.

To operate, wood is placed on trucks on track
3 and the whole rolled into retort B F. The re-
torts are made of brick or iron surrounded with
an envelope of brick or other suitable material,
tbe space between being filled with sand so as
to stop up any leaks that might occur in the re-
torts. Hot rosin or other preserving agent is
pumped from the heating vat 6 into the retort, this
fluid not being hot enough to decompose the woody
fibre, but at the same time being sufficiently hot
to distill the turpentine. Instead of applying heat

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

to the retort, the rosin when it becomes cool is
pumped through the heater 24 and is reheated, a
continuous circulatory system being kept up by
means of pump 20.

These retorts are preferably arranged in pairs,
as shown and provided with connections so ar-
ranged that one retort may be cleaned and re-
charged while the other is being operated, thus

FIG. 67. DAVIS' PROCESS.

effecting a great saving in time and obviating the
reed of repumping to and from the main source
of supply of the distilling and preserving fluid.

The vapors from the distillation pass out the
openings 32, 33, to the condenser 36, where they
are condensed and collected.

There are two processes devised by Weed, using
a bath of rosin, one for distilling terpenes only

and the other for distilling terpenes and also the
wood itself. The latest process only is illustrat-
ed. Fig. 68 represents the arrangement of the
apparatus.

To operate, wood is placed in the retort a on
the netting g, situated above the perforated steam
pipe d. Rosin is melted in the boiler p and
pumped out by pump o directly into the retort.
As it cools it is drawn through pipe i to the
branch s, then again to the pump o. This time
it passes through coil 1, which is heated by fur-
nace m and then into the retort through per-
forated pipe j. As it issues from these perfora-
tions, it comes in contact with the steam coming
from pipe d carrying with it the vapors of tur-
pentine whicb pass out through c to a condenser.

When the distillation is finished, the hot rosin
is allowed to flow back through valve z to the
boiler p, where it is kept hot for the next charge.
Of course, it could be pumped into another retort
if desired. The wood is then withdrawn.

In the other form only the retort is used. The
rosin and wood are put into the retort and a fire
started under the bottom and the heat raised to
the required point, the volatilized products pass-
ing to a condenser.

Neither form is as good as Davis', although they
have been used. '

In the Craighill and Kerr process, the wood is
treated with a dilute solution of caustic soda in
order to hold back the resins and acids, and tben
steamed in the usual way at a temperature of 110
degrees C. The vapors can be passed through a
bone-black filter if desired, before condensing. To
remove the rosin, etc., water is added to submerge
the wood, steam is applied and the wood is di-
gested at a temperature equal to the boiling point
of the alkaline solution with which the mass was
saturated and the digestion continued until the
rosin has completely entered into combination by
saponification with the alkaline solution. There-
upon the solution is drawn off and the wood well
drained.

To make fibre, the wood is digested under pres-
sure with caustic soda solution of 1.075 to 1.10 sp.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

gr. As this solution attacks the fibre if the heat-
ing is prolonged, only a portion of the coloring
matter is taken out and the solution withdrawn.
A solution of sodium carbonate is then added and
the heating continued with or without pressure
until more of the coloring matter is extracted, leav-
ing the fibre about the color of light manilla wrap-
ping paper. The fibre is then bleached by chlori-
nated soda.

This process will need close watching with vari-
ous kinds of wood on account of the different de-
grees of fatness. The rosin can be recovered only
with difficulty.

Hale & Kursteiner don't use any caustic soda

thinate has been so removed may be subjected to
destructive distillation in the ordinary way and
for ordinary purposes." It is claimed all of the
gums, etc., are eliminated from the wood.

The operation of the process is simple. The
wood in blocks enters at A3. Water heated to 130
degrees Fah. by means of steam coil B2 is added,
and the temperature raised by means of the gas
burner C to about 210 degrees or 211 degrees Fah.
As the gums exude and float, they overflow
through pipe F into the still G, passing through a
glass observation bulb F2 on the way. By this
contrivance it can be seen whether any gum is
coming over with the water. As it is necessary

FIG. 68. WEED'S PROCESS.

or steam in their process, shown in Fig. 69. This
invention is based upon the discovery "that when
wood is subjected to the action of a bath of water
maintained at a temperature just below the boil-
ing point or approximately 212 degrees Fah., the
terebinthinate or gum will separate from the wood
and retaining its turpentine or its volatile or
more buoyant constituents will rise to the surface
of the bath, whence it may be removed or caused
to flow over to a suitable still in which it may
be subjected to a distilling operation for separa-
tion into its constituent parts, turpentine, rosin-
oil and rosin. The wood from which the terebin-

to let water overflow with the gum, this water is
drawn off through cocks 1, 2, 3, 4, 5, wherever a
layer of it is found. Some water is left in the
still with the gum and when the still is sufficiently
full it is heated by vapor burner Gl to about 215
degrees Fah., when the turpentine distills over
clear and white. After the turpentine and water
are distilled, the rosin remaining can be distilled
for rosin-oil or drawn off as rosin.

Claims are made that from 128 pounds of rich
long-leaf straw pine wood during a period of from
three to five hours, one gallon of high-grade tur-
pentine and about twenty-five pounds of rosin of

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

fine quality are obtained. This is about the same
yield as from other processes.

Unfortunately, others who have tried the same
process several years ago, using very rich pine
coming from a yellow pine saw mill, do not seem
to be able to get any satisfactory results. This
shows that the process requires too much skill in
order that the ordinary operator might succeed.

It is possible that in some cases that an extrac-
tive process might prove of service under some
conditions, particularly when working with very
fat wood. To supply this possible want the author
has devised an apparatus which consists in chip-
ping the wood to the size required for paper stock
or the like and then bringing it into a chamber
in a continuous manner, where it is acted upon
by a suitable solvent, such as ether, carbon bi-
sulphide, carbon tetra chloride, alcohol, etc., this

solvent being continually reused and kept in circu-
lation in a suitable manner; the extracted matter
being removed from time to time and the solvent
evaporated and condensed. The fibre left is white
and soft. The residue left after evaporating the
solvent is distilled with steam, which removes the
turpentine, the rosin remaining in the still from
whence it can be withdrawn hot. The color of
the rosin depends upon the color and age of the
wood, dead wood giving a light red, which can
be bleached, if necessary.

Conveyor Processes. Under this head will be
described those processes which use conveyors of
some kind to make the wood pass through a heated
zone. The first of these was probably Kalliday's,
which has been mentioned under rotary retorts.
Another retort said to be better than Halliday's
is that of Bowers. In this process a long rectangu-

FIG. 69. HALE & KURSTEINER PROCESS.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

lar box, not over a foot or two high, is divided
into parallel segments by means of partitions. At
the end of each partition is set a pulley or sprock-
et wheel on a vertical axis. A continuous chain
conveyor works in and out of each partition. Ar-
rangements are made for tightening the chain,
when necessary, while the distillation is in prog-
ress. To make a bend in the conveyor, the flights
of the chain are hung from the side of the chain
and thus pass under the sprocket wheel while the
sprockets engage the chain above the flights.

The sawdust enters at one end of the apparatus
and as it winds back and forth in advance of the
conveyor flights it is completely distilled. The

same apparatus, when gently heated, is used as a
dryer. It is said that much success is encountered
using these retorts for distilling hardwood chips,
a brick furnace being used for heating purposes.
Generally two are used; one for drying and the
other for distilling. Such a system might be of
service in distilling fat pine; the first retort tak-
ing off the turp and the second one the tar.

The next patent, that of Dobson, agitated the
lumber trade for a while. It is a very slight mod-
ification of a Russian process, which never ma-
terialized. The type is so distinctly different from
the others that were exploited at the time that it
is interesting to know wherein its usefulness lies.

FIG. 70. DOBSON'S PROCESS.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

It is a definite project to advance ground-up wood
by means of suitable conveyors, directly through
a brick furnace, and while passing through the
cooler parts of the furnace, the wood is to be
pressed and steamed, thus expressing the tar and
distilling the turpentine; the residual wood to be
used for paper making.

In the illustration, Fig. 70, a brick furnace is
shown at Fig. 3 with grates on both sides, 4. The
conveyor space is shown at 3 and is arranged so
that the furnace gases are excluded.

The operation of the process would be simple
enough if it would work at all, but the inventor
fails to make any arrangement for the collection
of the turpentine vapors. The material passes

In the Kerr process is a device which ought to
work well, provided the form of screw conveyor
shown is suitable for moving chipped wood. The
illustration, Fig. 71, shows the arrangement very
clearly.

The ground wood enters the hopper 5 and falls
upon the screw conveyor 4. Steam enters through
the shaft by means of port holes 6, the vapors
from the wood passing through 9, 9, 9, etc., to a
condenser. With high pressure, the steam would
also blow out through the hopper, so only light
pressure steam should be used.

When the wood gets to the end of this conveyor,
it drops down 13 to another conveyor, which* does
not fit the trough so closely as the first. Here

^^,/spiryipi .rjCffl-

\T/zi^lW7it/iYyifTyif\y/iv7[i i

FIG. 71. KERR'S PROCESS.

through the furnace on the conveyor, where it is
heated sufficiently to draw the resin, steam being
added to facilitate the operation (turpentine would
escape and an outlet to a condenser should bave
been made). When the material reaches the rear
end of the furnace it is passed through a series
of squeezing rolls, 9, 10, 11, Fig. 1, and thence out
at the rear end. Such an operation could never
work with sawdust, as was intended, as there is
scarcely any resin in it, and only under careful
operating with fat pine. By heating the hogged
wood without using live steam, it might be pos-
sible to sufficiently melt the rosin so that most of
it could be squeezed out. It would seem, though,
that some turpentine must be lost unless some
provision were made for collecting it.

the wood is treated with the alkaline solution
mentioned in Craighill and Kerr's process, the
level being kept by means of the overflow pipe 16.
Steam is admitted to the trough in a similar man-
ner as it is in the first one, but for the purpose
only of keeping the alkaline solution hot.

This form of continuous process is very effective
for the removal of turpentine. One trouble would
be that the chips would blow through pipe 9 into
the condenser pipe. This could be prevented by
using screens. Another trouble is the expense of
the construction. A screw conveyor 4 inches in
diameter will deliver 100 bushels (equal to 118
cubic feet approximately) in one hour. The usual
time of distillation with sawdust, as ordinarily
practiced, is one hour for each particle of wood.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

With a 4-inch- conveyor with a distilling period
of one hour the trough should be large enough to
hold a cord of wood in order that all the wood
passing through might be acted upon for one hour.
This would require a trough over 1,500 feet long.
With a screw 3 feet in diameter, the trough would
have to be nearly 20 feet in length*. It would be
better to use a rotary retort with a small con-
veyor at each end. But with a distilling period
of only 15 minutes or less, then the trough would
be made much smaller and this apparatus would
be very efficient.

An apparatus working on the same principle has
been in use in another industry for some time.
Instead of using one long conveyor several are
placed one under the other and the whole encased
with a suitable covering.

There are several patents based on this same
principle, each with a screw conveyor in a closed
trough, some using steam and some hot gases. It
is difficult to distinguish any material difference
in most of them.

The Heidenstam process is a device by means
of which an attempt is made to briquette sawdust
and then distill the briquettes to make charcoal

and by-products from the wood contained therein.

Very elaborate plants have been designed for
carrying out this process, but it is doubtful if any
of them will pay, and it is certain that they will
not in this country, where charcoal, the only prod-
uct now of much value that is produced by this
method, can be cheaply obtained. Formerly the
production of wood alcohol by this method might
have made the process useful in the hardwood re-
gion, but now that the tax has been removed from
grain alcohol, this feature is lost. The process is
very ingenious and has one point that is very im-
portant, and that is the pressing of the briquettes
while distilling.

. The great objection to the process is the diffi-
culty in compressing sawdust. Many attempts have
been made to do this by engineers so as to make
a more compact fuel, but they have all signally
failed unless a very expensive and uneconomical
binding agent is used. By the above method a

very poor briquette is formed, and it is only by
the action of a poor compressing apparatus in the
retort that any hard charcoal briquettes are formed
at all, and these only few in number as compared
with the total carbonized.

For pine wood this process is scarcely suitable,
for it is easier to take the turpentine out before
briquetting and thus the only good briquetting
would do would be to make the sawdust or ground-
wood suitable for charcoal when sawdust is used,
or charcoal and tar when fat wood is used. Char-
coal and tar can be made from fat wood, if nec-
essary, without first hogging it, and to treat saw-
dust in this manner simply for charcoal could not
possibly pay. The by-products from pine wood,
such as wood alcohol and acetic acid, are not of
sufficient importance to count on, and at most
works, when incidentally produced, are not saved.

If it should be advisable to make charcoal from
sawdust or hogged wood, which might possibly
be the case when located near a blast furnace, it
would be better to carbonize in a rotary retort,
such as one of those described, which could be
done in one-fourth the time needed when the wood
is in solid form, and tnen briquette the charcoal,
using the tar formed as a binding agent. With
sawdust the tar formed would be of such poor
quality that this would be a good way of utiliz-
ing it.

A method of distilling by superheated steam has
lately come into use in Sweden. Although the use
of superheated steam for charring wood has long
been known, hardwood distillers did not use it
much, because it diluted the acid liquors too much.
It has the further disadvantage of requiring large
condensers and stronger retorts.

A series of retorts are used, each holding 200
to 1,000 cu. ft. The hottest steam is introduced
into the one most nearly charred and the coolest
steam into the one just charged. Ten retorts are
used in a series and carbonization is completed in
12 to 20 hours and drawing and charging in four
to five hours, so that each retort can be worked
off in 24 hours. The greater part of the heat is
required for evaporating the moisture contained

100

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

in the wood, but cooler steam can be used for this
purpose and hotter steam for charring. The steam
together with the gases evolved from the wood
pass from one retort to the next, and so on. When
carbonization is completed in one retort saturated
steam is passed in for one hour and this becomes
superheated to some extent and after passing
through the superheater is used for completing
the charring of the next retort. After the steam,
water is introduced into the retort in small quan-
tities and afterwards for one hour a fine spray of
water is showered upon the charcoal, which- is
then ready to be drawn.

The heavy oils are condensed and fall into a
covered tank containing boiling water. The steam
and gases from the finished retort are led through
this tank and serve to heat the water where the
heavy oils are condensed. These oils have a boil-
ing point of 200 to 250 degrees C., and by using
superheated steam the yield is said to be increased
17 per cent and the oil to be of much better qual-
ity. In the further description of this process,
the wonderful statement is found that only 15 per
cent of the weight of the charcoal produced is
needed for fuel.

To avoid diluting the distillate with water when
superheated steam is used for carbonizing, Was-
bein used hot gases direct from a gas producer to
distill the wood. The charcoal produced is used
in the gas producer. This requires careful ma-
nipulation and large condensers, as not only the
distilled products from the wood, but also the hot
gases must be cooled. Processes of this kind are
used in Germany.

Pierce Process. In this process as described by
Landreth Proc. A. A. A. S'., 1888, the charring of
the wood is effected in circular, flat-top, brick kilns
holding 50 cords each. The wood is charred by
heat produced by gas burned in a brick furnace
under the kiln, and into and through which the
products of combustion pass. The gaseous prod-
ucts of the dry distillation of the wood pass from
the kiln to the condensers, where the tarry and
liquid products are condensed and the gas sent
back to the kiln. Thus, none of the charcoal pro-

duced is burned to carbonize other wood, as in the
common pits or ovens. The gas which elsewhere
is wasted is here not only sufficient to effect the
carbonization of the wood, but furnishes fuel for
the boilers required about the works.

In another description of the process it is stat-
ed that there is a large amount of gas left over.
The gas burned under the furnace passes through
the red-hot charcoal in the kiln, thus causing the
carbon dioxide to be reduced to the monoxide at
the expense of the charcoal.

Such a process, although largely used in dis-
tilling hardwood, cannot be very well applied to
pine wood. The gas produced by pine wood dis-
tillation is not sufficient to effect carbonization,
besides pine wood should never be heated to such
a. degree that carbon dioxide would be reduced
to carbon monoxide.

Although all these processes that have been de-
scribed relate chiefly to pine wood, yet all the de-
structive distillation processes could be applied to
hardwood by simply omitting the part that re-
lates to the turpentine. Instead of working up
the oils, the pyroligneous acid is saved and wood
alcohol and acetates made in customary manner.
A description of a German process for carbonizing
pine will be given later, wbich utilizes the
acid in this way. All the pyroligneous acid that
is made by distilling pine by the foregoing proc-
esses can be treated in this manner. The yield
is so small, however, that it hardly pays.

The patents herein described are given below
in the order of their application.

Wheeler, 7-5-1870 Krugr. 10-1-1903

Messau, 7-3-1872 Matthieu, 10-12-1903

Stanley, 1872 Palmer, 12-9-1903
Hansen & Smith, 10-10-1885 Dobson, 12-23-1903

Berry, 12-15-1885 Mallonee, 12-23-1903

Wheeler, 8-26-1886 Hoskins, 2-1-1904

E. Koch, 3-1-1887 Broughton, 6-13-1904

Smith, 12-13-1887 Fiveash, 6-24-1904

A. Koch, 8-13-1889 Davis, 7-16-1904
Koch & Danner, 8-26-1889 Harper, 7-22-1904

Badgley, 4-8-1890 Fleming, 7-28-1904

Inderleid, 7-1-1892 Hirsch, 8-1-1904

Spurrier, 9-10-1898 Palmer, 8-20-1904

Spurrier, 10-11-1898 Ross & Edwards, 11-11-1904

THE UTILIZATION OF WOOD WASTE BY DISTILLATION. 101

Larsen, 10-7-1899 Handford, 12-27-1904 Viola, 1-28-1903 Kerr, 9-28-1905

Weed, 1-6-1900 Copilovich, 1-12-1905 Palmer, 5-11-1903 Craighill & Kerr, 10-3-1905

Weed, 2-15-1901 Williams, 1-16-1905 Bilfinger & Halleck, Jackson, 10-11-1905

Roake, 6-21-1901 Gardner, 3-11-1905 4-25-1903 Davis, 10-23-1905

Gilmer, 6-25-1901 Sibbett & McLean, 6-20-1905 Clark & Harris, 6-10-1903 Snyder, 12-1-1905

Adams, 12-27-1901 Jewett, 6-29-1905 Bilflnger, 7-11-1903 McMillan, 3-24-1906

Chapman, 3-17-1902 James & James, 7-6-1905 Mallonee, 7-18-1903 Craighill & Kerr, 4-17-1906

Viola, 1-15-1903 F^iis, 9-28-1905 Douglas, 9-1-1903 Hale & Kursteiner, 8-14-1906

CHAPTER VII.

THE EXECUTION OF THE PROCESSES OF WOOD DISTILLATION.

A description of each individual process cannot
be given in detail here, but one of each general
kind can be given as a type. In distilling it is .
absolutely necessary to work for certain definite
products so as to obtain large yields of tbese.
"When working for large quantities of turpentine
more time needs to be taken and the heat kept
low so as not to draw out tar. In the same way
when working for large quantities of tar the dis-
tillation must take place slowly or large quantities
of gas will be found at the expense of the tar
and charcoal.

The Steam Process. In this process it will be
considered that a series of vertical retorts are to
be used set in a row. Above each retort should be
a bin, unless each retort is worked alternately. Un-
derneath the retorts should be troughs of sufficient
size to hold the residue dropped from the retorts.
In this trough should run a conveyor to the boil-
ers, or elsewhere. Above the bins and retorts
should be a conveyor from which the ground wood
from the hog drops by means of suitable chutes
to the bin or retort.

To start the plant the first retort should be
filled with wood and steam turned in until the
pressure reaches not over 5 or 10 pounds, or
such pressure as is determined upon. At first it
is advisable to allow the steam to rush in rather
rapidly in order to quickly heat the retort. The
stirrers should be started and the distillation con-
tinued until all the oil has been distilled over, or
rather until only such a small quantity is pres-
ent in the distillate as to no longer pay to con-
tinue. The steam as it warms the retort soon
finds its way to the condenser, and there with the
oil is condensed and flows out to the receiver.
The proportion of oil and water varies with the
richness of the wood, most of the oil coming
over in the first part of the operation.

This oil is not pure, but consists of oil and resin-
ous matters, with a small proportion of ethers,
aldehydes and ketones, which gives it a decided
odor. Oil is only slightly soluble in water, and
it is only necessary to allow the mixture coming
from the condenser to settle when the water goes
to the bottom. By using two or three tanks the
oil from the first one, containing water in sus-
pension, overflows into the second one, where more
water separates, and from thence to the third, by
which time enough water is taken out to furnish an
oil suitable for simple redistilling in order to
make it ready for the market.

It is claimed by some that in distilling saw-
dust only the gum turpentine found in the sap is
distilled by the steam, but such is not the case,
for not only is the gum oil distilled, but also that
contained in the heart wood. In addition to this,
resin comes over mechanically, thus coloring the
crude product, but not giving it the bad odor that
would come if the tar was started.

In the' meantime, the other retorts are filled
and started, and the material still coming in the
conveyor is allowed to fall into the first bin. In
the case of sawdust the first retort would prob-
ably be distilled by the time the other retorts
were filled, and the bin would not be necessary.
However, if the first retort is not finished, the
material should be collected in the bin and the
bin fitted with a large opening at the bottom to
allow the material to drop out quickly into the
retort when required. The charge being worked
off, the steam valve is closed, the bolts taken off
the door at the bottom is opened, and the residual
material allowed to drop out. The door is again
fastened on and a new charge dropped in from the
bin above. The residue is conveyed to the boiler.

A modified working of the process is to use sim-
ply two retorts, or steamers, and have them of a

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

103

size sufficient to handle all the raw material. By
filling one while the other is distilling the use of
bins is not necessary. It can be seen, though,
that this means two retorts against a bin and a
retort, and, as a bin ought to be the cheaper, this
modification means greater initial cost for retort.
In addition, with two retorts each would have to
have special valves and connecting pipes, which
further increases the initial cost. The gain would
be in the saving of time in dropping the distilled
material out and filling the retort from the bin,
a process which ought not to take much time.
Even if stirrers could be used satisfactorily, it will
be found that the sawdust will pack and scaffold,
or arch, thus making sawdust expensive to distill
and to discharge.

It will be seen that the execution of the steam
process is not a very difficult matter, and all that
it needs in the way of labor is a man of sufficient
intelligence to take care of a boiler when a hog
is not used and an ordinary stationary engineer
when a hog and engine are used. Of course, on
a large scale where considerable product is made,
good superintendence is necessary in order to ob-
tain the most economical workings.

Steam and Destructive Distillation. In this proc-
ess we have a more difficult proposition than in
the plain steam process. Neither this process nor
the one to follow have any especial advantage, un-
less charcoal is to be made, consequently the proc-
ess should be made to yield as much turpentine in
the first stages and as much tar and charcoal in
the later stages as possible, and but little gas.
Although the gas formed has a high heating value,
it takes more fuel to make it and at the same time
the yield of the more valuable by-products of the
wood is less, particularly of charcoal.

This is the process the writer would recommend
when the three primary products, turpentine, tar
and charcoal, are wanted, but for turpentine and
tar without charcoal a special process, to be de-
scribed later, seems to be the more suitable.

In the preparation of the wood a general idea
must be obtained from experiment as to the yield
in turpentine from a cord of four-foot wood, two-

foot wood and one-foot wood in fifteen hours' heat-
ing. From this data can be obtained the in-
creased value, if any, that is occasioned by saw-
ing the wood into short pieces. The wood pre-
pared in the proper manner is then charged into
the retort, either by means of cars or by hand,
and the doors fastened, gauges, etc., adjusted, a
fire started in the furnace, and the heat raised as
quickly as possible to 212 degrees Fah., without
injuring the brickwork and retort seams. This
takes from one to three hours, according to the
size of the retort, then superheated steam is al-
lowed to enter the retort in considerable quantity
until the contents thereof are brought to approxi-
mately 325 degrees Fah., when the supply of
steam should be cut down so that a considerable
portion of the condensed matter is oil, say not less
than one-twenty-fourth. The heat is maintained at
325 degrees Fah., not because the oil will not dis-
till at a temperature less than this, but because
it is necessary for the heat to penetrate to the
inside of the block of wood and thus draw out all
the oil and resin. Care must be taken not to go
above this temperature or the wood would begin
to decompose and empyreumatic vapors come over.
Cellulose begins to decompose at 320 degrees Fah.,
but only slightly. Wood is a poor conductor of
heat, and it is not definitely known how large a
block may be, and at the same time be small
enough to allow the heat to draw the resin from
the middle of the block when the outside tem-
perature is 325 degrees Fah., nor is it, definitely
known how long it would take for the heat to
penetrate to the middle when the temperature
outside is held at that degree. There is no rea-
son why this cannot be determined, and it prob-
ably will be soon.

The amount of distillate which comes over by
this treatment need not be large, but should be
a very decided quantity. It is better, though, to
use furnace heat as much as possible, so as to
have the furnace hot, ready for the second part
of the operation, so only enough steam should be
used to carry over the vapors. This saves con-
densing water, also. When the condenser hasn't

104

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

been used for some time, a green colored oil is
obtained at first, due to the dissolving by the oil
of the copper acetate left in the pipe from a pre-
vious distillation. Often the oil is water-white at
first, quickly changing to yellow, and then to am-
ber as more and more resin is distilled. When
the amount of oil falls off and the temperature
in the retort still remains the same, it is an indi-
cation that most of the light oils have been dis-
tilled, and that to obtain heavier oil with a higher
boiling point the heat must be increased. The
appearance of gas about the fifteenth hour after
starting when the retort has been gradually heat-
ed indicates a changing point. The oils coming
over can be tested with a hydrometer, if desired,
but with proper firing the receiver should be
changed and any gas apparatus coupled up if not
already in position. Steam can now be left on or
closed off, according to the notion of the operator.
The author prefers to use steam throughout the en-
tire operation, even when an exhauster is used, as
a certain effect is produced that might not be other-
wise. As no acetic acid is usually recovered, the
excess of water in the distillate is not much to be
feared, unless the proportion is such that the tar
and acid will not properly separate.

From now on the progress of the distillation
can be determined in various ways by experienced
men. The heating should not be great enough to
cause back pressure from the gas, and at the
same time a steady stream should flow from the
end of the condenser with weak force. The gases
formed are at first blue when ignited, from the
combustion of the carbon monoxide, and as the
distillation proceeds this flame becomes gradual-
ly yellow, and toward the end of the distillation
the heavy white yellow flame of the heavy hydro-
carbons makes its appearance and continues un-
til the distillation is finished.

Of course, the distillation can still be carried
on by means of an ordinary thermometer until the
last stages are reached, when it is necessary to
use a pyrometer of some kind, or a special 1000
degree Fah. mercurial thermometer. When the
temperature reaches 500 and in some cases 600

degrees Fah., some operators change the receiver
again and then continue the distillation to obtain
the thicker tar. Others collect the entire tarry
distillate in one vessel and then redistill. Ordi-
nary distillation would be finished when the tem-
perature reached a few degrees over 800 degrees
Fah., but in some cases, owing to the formation
of paraffins of high boiling points it is better to
run to about 900 degrees Fah. The author has
sometimes been obliged to go even higher than
that. With separate condensers for each retort
the end point is readily ascertained by the slack-
ing off in the quantity of the distillate. When this
point is reached the fires can be withdrawn and
the gas turned into another fireplace. The heat
of the furnace walls will be found to be sufficient
to complete the distillation. By having the fur-
naces hot at the time the wood is ready to decom-
pose the destructive distillation itself requires but
eight hours in a three-cord retort. If lined with
brick the retort will not be specially injured.
When the distillation is ended the retort will be
found to be red hot on the bottom. It is allowed
to cool until the iron becomes black, when the
charcoal is drawn. The residual gas remaining in
the retort should be touched off like when making
coal gas, and the admittance of gas from other
retorts prevented. The heads are then removed
and the charcoal immediately withdrawn. Using
cars, the products can be easily pulled into cool-
ers without much loss from burning. Others sim-
ply draw the charcoal into a pit and wet it with
water or cover it with wet charcoal dust. Some
drop the charcoal into cars and lute on a sheet-
iron cover.

Destructive Distillation. This process is carried
on exactly the same as the foregoing in the latter
part of the operation and very similarly in the
first part, except no steam is used, consequently
the first distillates are smaller and darker. The
first portion is usually caught in separate re-
ceivers, but this is not always the case.

A rather complete plant for the utilization of
pine wood as carried out in Germany is shown in

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

105

Fig. 72. This is a plan of a plant for distilling
ten cords of pine wood in twenty-four hours.

The wood is brought in on cars on the track A
fitted with suitable turntables, B, B, B, B. To use
the labor employed properly the retorts are charged
one after the other, instead of all at once. The
retorts (c, c, etc.) on the left would be charged
first, and those on the right last. The distilla-
tion proceeds in the usual manner, the vapor be-
ing condensed in the condensers D, D, etc., two
pipes being in one cooling box. The distillates
from all the retorts go down pipe E to the tank
F, F, F, where the oil and acid separate. The
oil goes to the tank G, and the acid containing
the wood alcohol is either sent to one of the stills
J, J, or to the tank H to be first neutralized with
lime. In making brown acetate the lime is added
to the liquor in H and the excess of lime and
sediment removed by the filter press I. The liquor
is then transferred to an iron still J and the alco-
hol distilled. To make grey acetate several meth-
ods are employed. In one the acid and alcohol are
distilled in the copper still J, leaving the tar as
a residue. This tar is forced in a spray under
the boilers and used for fuel unless the market
price warrants its sale. The alcohol and acid are

then brought to the neutralizing tank H, where
the liquor is exactly neutralized with lime and
filter-pressed. The alcohol is then removed by
distillation in the iron still J and collected at K.
Another method is to distill the crude pyroligenous
acid and collect the alcohol until the sp. gr. of
the distillates is 1 and then to change the re-
ceiver and collect acetic acid separately. This
acid is then neutralized and evaporated. Another
method is to distill the pyroligneous acid in a cop-
per still and to make the vapors pass through

A
i

r *"-)

-^*-

-*k_

JJ-

! c

i
c

-J-

B A

FIG. 72 GERMAN DESTRUCTIVE DISTILLATION PLANT.

106

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

milk of lime, which absorbs the acetic acid and
permits the alcohol to pass on to the condenser.
This latter method would take less fuel, as the
acetate liquor would be hot. It would be difficult
to regulate the supply of lime for neutralizing.

In the North a method is used whereby the
lime is added directly into the iron still from a
lime box situated above it. The still is furnished
with a stirrer to thoroughly mix 4h Hqtrhi, other-
wise the pyroligneous acid is treated by the first
method both for grey and brown acetate of lime.

The acetate or neutralized liquor thus produced
is evaporated to a thick paste in the steam-jack-
eted pans, L, L, furnished with stirrers. This
paste is then spread out on the acetate pans, M,
to dry, care, being taken not to char. At some
plants the drying takes place in rooms heated
with waste furnace or retort gases. (See Calcium
Acetate, Chapter X.) With this particular process
the acetate pans are located in the boiler room,
where the water pump N is also situated.

The alcohol coming from the still J is collected
until the gravity is about 1. This weak alcohol
is then sent to the still O and distilled. In this
still alcohol of .965 sp. gr. is converted into por-
tions, some as light as .816 sp. gr., containing 95
per cent alcohol. The general average of this still
is considered to be 82 per cent. Care must be
taken not to let the wood oil mix with the high
proof alcohol or it will render it non-miscible with
water. This is usually avoided by collecting the
different portions separately and returning some
of the liquor to be redistilled. With the German
method the first runnings consisting of more or
less colored liquor is caught separately until the
middle fraction begins to distill over. After the
middle portion distills, products with a higher
boiling point come over, their presence being first
noticeable by the turbidity of the distillate pro-
duced when water is added to it. Subsequently
the distillate itself is rendered turbid and eventual-
ly it comes over in two layers, oil and water.
Finally only water comes over, impregnated with
empyreumatic substances. The alcohol rendered
turbid by water can be treated in two ways; it

can be added to the turbid distillate and the mix-
ture added to the next charge of crude in the
same still, or it can be diluted until it shows a
specific gravity of 0.934 and allowed to rest for a
few days, when the greater portion of the hydro-
carbons separate as an oily layer on the top, and
can be drawn off. The alcoholic fluid left is re-
distilled over time and makes strong alcohol that
does not become turbid upon the addition of
water. The oily fractions are mixed together and
redistilled separately, when a further quantity of
middle fraction is obtained. The wood oil ob-
tained is known as red oil, and is usually burnt.
By distilling the strong alcohol obtained from the
above still after adding a little sulphuric acid in
the still P a very strong highly refined alcohol
is produced.

At some plants the crude wood alcohol is passed
through towers containing wood charcoal, which
serves to remove some of the ketones, aldehydes
and tarry matters.

None of these processes serve to remove ace-
tone. To do this several methods are used; one
is to form a compound of wood alcohol and cal-
cium chloride, which is stable at 100 degrees C.
By gently heating the acetone is driven off, and
then by adding water and raising the temperature
to 100 degrees C. the calcium chloride compound
decomposes and the methyl alcohol distills. Oth-
ers add caustic potash and iodine until the yellow
color disappears, then distill. (Regnault & Ville-
jean.) The watery alcohol is repeatedly rectified
over lime, and finally over sodium or phosphoric
anhydride to remove the last traces of water.

The crude turpentine oil containing the tar, re-
sin, etc., is taken to the tank G, from whence it
enters still R, where the light oils are removed
and are collected in tank S. From S the oil goes
to the washer T, where it is washed with alkali
water, acid, and again with water, and then recti-
fied in the fractionating still U, and is then settled
ready for shipment. The tar is removed from the
still R and is immediately ready for shipment.
The residues from the other stills are mixed with
crude oil and again distilled until they begin to

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

107

accumulate, when they are otherwise disposed of.
The charcoal left in the retort is taken out by
means of a chain fastened to a scraper, placed in
the rear of the retort, and dropped into an iron
bogie running on the small track. The bogie is
covered with sheet iron and the edges luted with
' clay to exclude air and the whole rolled away to
cool in a storehouse. It is . necessary to have one
car for each retort, and about three for bringing
in the wood.

Special Process. The use of a rotary retort
should be described here, as the author believes
that this method will eventually be the one used
to utilize all kinds of waste wood, particularly the
average dead pine found in the woods. Wherever
such pine can be found yielding four gallons of
turpentine to the cord and not costing over $1.50
per cord, delivered, this process can be success-
fully employed. Under such disadvantageous con-
ditions the closest economy in working is neces-
sary.

The combination of apparatus suggested would
be two rotary retorts, a boiler, a superheater, a
blower, an exhauster, two condensers, two stills
and condensers, one water pump and a hog. Those
who prefer mixing the distillates need have but
one retort and condenser and extra still. A con-
veyor from the hog to the retort would be needed
and one from the end of the retort to the boiler.
The wood should be hogged in the usual manner
and brought to the retort for distillation. In the
first retort the turpentine should be worked off
and condensed and the chips discharged into the
second retort, where they are thoroughly charred
by means of superheated steam, hot inert gases,
or by means of fire gases passing through special
flues or through the wood itself.

With fat wood each operation should be per-
formed in six hours and the charred wood used
for fuel in addition to whatever other fuel is
needed. The tar carried over by the steam is
condensed in the usual manner, and then redis-
tilled to recover any light oils, and by passing a
current of superheated steam through the mass
while hot sufficient of the heavier oils can be

carried over and the tar left of the proper con-
sistency. By this method of operating the tar
obtained would be of sufficient value to pay for
tire fuel and wood, and the turpentine to pay for
the .labor and leave a small profit in addition.
Charcoal is of no value In ^ost communities ex-
cept in small quantities, so this method -would
probably be the best that could be devised to
treat the average wood found in any locality. It
offers further attractiveness in that when the sup-
ply of wood is exhausted the entire outfit could
be easily removed to another .place. For those
who prefer to use but one retort it is best to
have it long so that the end farthest from the
feed can be heated to the charring point, and the
hot gases led out through a pipe at the feed end,
the heat from these gases thus being utilized to
partially distill the incoming wood with which
they come in contact on the passage through the
retort. The products can then be refined. In all
cases it is better to coat the shells of the retort
with asbestos, or other covering, so as to pre-
vent radiation as much as possible. ,

In those cases where very poor wood is used
it might be that the tar made became too dark,
owing to the lack of resin. This might be mixed
with the fine charcoal and briquetted and sent to
an iron furnace, or again distilled to form spe-
cial charcoal bricks such as are used in foot-warm-
ers. It can be readily understood that in these
cases only a small plant could pay, as the de-
mand for charcoal in the latter form would be
limited, indeed. With blast furnaces the results
would be more encouraging and a large plant
would be needed. This would be an easy way of
solving the problem in such districts. It is claimed
by manufacturers of briquette machinery that bri-
quetting can be done for 50 cents per ton. By the
ordinary method of distilling large wood it takes
from twelve to twenty-four hours to char, whereas
by this method only six hours is necessary, so this
difference in time would more than pay for the
cost of briquetting.

Wood Gas Making. So far it has only been in-
timated that wood gas is yielded in the destructive

108

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

distillation of wood in sufficient quantities to pay
for working for gas alone. However, the yield of
gas ranges from 20 to 50 per cent of the weight
of the wood. By ordinary distillation 20 to 30
per cent is the usual yield, but by rapid heating
the yield is greatly increased. The weight of 1,000
cubic feet of wood gas is about 50 pounds at 62
degrees Fah., so a ton of sawdust might, under
certain conditions, be made to yield 1,000 pounds
of gas, or about 20,000 cubic feet, whereas one ton
of the best gas coal from Grahamite, W. Va., gives
but 15,000 cubic feet of coal gas and most coals
only about 10,000 to 12,000. Wood gas must be
purified with lime to remove the carbon dioxide,
and then it has an illuminating value, according
to Liebig, of 6 to 5 compared with coal gas. (See
analysis of wood gas under Chapter XII.)

To carry out the process of making gas, several
methods are used. One consists in heating the
wood in ordinary retorts and then passing the va-
pors through a superheater, which decomposes
them and forms uncondensable gases. One meth-
od is to throw the wood as quickly as possible
into a glowing retort and to collect the gases in
the ordinary manner. Another utilizes the princi-
ples of a water gas apparatus, and treats the wood
in a similar manner. Another method is to col-
lect the gas separately, then by using the char-
coal in a water gas system the charcoal can be
glowed by the air blast and the wood gas passed
through it to decompose as far as possible the
carbon dioxide contained therein, then steam added
until the temperature became too low for decom-
position. If the charcoal was too expensive, coal
or coke could be used. Then the distilling method
with hot gases, or preferably producer-gas, could
be used.

An attempt will not be made to enter into the
details of operation of these various methods, as
wood gas manufacture is not apt to be a nourish-
ing industry, owing to the fact that the proper
place to make wood gas economically would be
in the woods, because wood is too bulky, as com-
pared with coal, for transport; and it is not to
be expected that it would pay to transport the

gas even by pipe line, except in those cases where
the gas could be made near the city.

The author would suggest the possibility, how-
ever, of utilizing sawdust for gas making in those
States where lumber mills are located in com-
paratively large cities. To do this it would be
necessary to use those forms of apparatus spoken
of for distilling sawdust destructively. Of these,
Larsen's and Harper's rotary retorts, Halliday's
screw retort, and Bower's chain retorts might be
used. The last two are usually enclosed in brick
so no further modification would be necessary.
With pine or fir distillation the turpentine could
be taken off in a previous operation and the resi-
due destructively distilled for gas. Larger vapor
pipes and condensers would be necessary, owing
to the sudden formation of gas when the wood is
brought in contact with the hot retort. In all
cases it is presupposed that the wood has been
dried. To use the gas under a pressure of 1-12 to
% inch of water, bat wing tips having a width of
about 0.0394 incb give the best results. A "Wels-
bach mantle is also very serviceable.

A method used in France endeavors to utilize
wood in generators that are designed to supply
gas for motors. The consumption of ordinary
wood for such purpose is about five pounds per
horsepower hour. The heating is done from top
to bottom. The wood that first enters is charred
and falls to the bottom as red-hot charcoal. The
air blast having been heated by the pipe through
which the gas is escaping, enters the top of the
generator and, coming in contact with fresh wood,
partially distills it, and the products of distilla-
tion pass through the red-hot charcoal at the bot-
tom, thus decomposing the tar to form more gas
and the combined vapors and gases pass out at
a pipe at the bottom through a filter and then to
a separator. It can be seen that unless carefully
regulated the supply of oxygen in the air would
be exhausted before reaching the charcoal at the
bottom of the generator and the charcoal remain
unburned. Arrangement is made for drawing this
residual charcoal into water, where the ashes will
sink and the charcoal float. This charcoal could

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

109

be dried and returned to the top of the apparatus.

Wood gas has some advantages over coal gas
when used in gas engines. For this reason at-
tempts may be made to utilize wood waste by
converting it into gas.

Any of the processes herein described that are
based on destructive distillation are suitable for
making gas. Those that arrange to protect the
retort from the effects of severe heating and those
that treat small pieces of wood effectively are to
be preferred.

Two forms of gas generators can be formed from
these classes of apparatus; one using closed re-
torts and the other being open for the admission
of air similar to a gas producer. As a gas pro-
ducer the apparatus would necessarily be of the
suction type, although in a few instances the type
using a blast could be employed.

Those familiar with coal gas generators can
readily add the necessary modification to wood dis-
tilling apparatus to bring satisfactory results.

CHAPTER VIII.

REFINING PROCESSES.

General methods of refining have already been
given and some special methods of refining have
been given under the different processes. The pat-
ents now to be described are considered chiefly be-
cause they show a definite method of carrying out
principles already in use or known, rather than
because they relate to any new methods or prin-
ciples.

Crude turpentine as it comes from the retort
is invariably more or less colored at some stage
of the operation, no matter what the process is
that may be used, consequently refining is neces-
sary to remove objectionable impurities. This
latter is especially true where all the products
of distillation are mixed together and then re-
fined.

In all methods of refining the same general

object is to be attained. The crude turpentine
may contain light and heavy oils and tar. The
object of refining then is to separate the turpen-
tine from these other ingredients when they are
present. Light oils in most processes are pro-
duced from the rosin by local action, while in
some destructive distillation processes the pres-
ence of light oils is always to be expected. In the
steam process, the objectionable impurity is a
heavy oil and is easily separated by ordinary dis-
tillation, the light oil coming first and the heavy oil
remaining in the still or collected separately.

Chemicals are often used, such as lime and
caustic soda and even acid; the use of mineral
acid is not to be commended as it bas a tendency
to change pinene into dipentene. All these chem-
icals have been in use for a long time, coupled
with steam distillation.

By noticing the methods described under the
following patents, a general idea can be obtained
of the methods used in refining the crude turpen-
tine.

Mallonee's Apparatus The method is shown in
Fig. 73. It consists of a series of similar units,
working separately in a similar manner. The

j "-^g

FIG. 73 MALLONEE'S PROCESS.

THE, UTILIZATION OP WOOD WASTE BY DISTILLATION.

Ill

operation of the stills shown, have been described
in part under Mallonee's process, Fig. 37. The
distillate from the retort is caught in three sep-
arate fractions according to the specific gravity;
the first fraction being caught from 0.855 sp. gr.
to 0.920; the second fraction from 0.92 to 0.96
sp. gr., and the third fraction from 0.96 sp. gr. to
the end of the distillation. The refining apparatus
shown in Fig. 73 deals entirely with the first two
fractions and the operation is carried on in a sim-
ilar manner with both fractions, the only differ-
ence being in the proportion of the different prod-
ucts which distill over.

The crude oil is placed in still 1 and heated in
the ordinary manner by means of steam (see Fig.
17, Steam Still). The light oil vapors pass up
pipe 8, which is about twenty feet in length, and
are condensed in the tubular condenser 9 and pass
into the receiver 23. To prevent the turpentine
vapors passing to the condenser with the light
oil, a spray of water is applied at 10 to cool the
vapor pipe, the water passing down the pipe to
the pan 12, from whence it is carried away. A
gas trap is shown at 22 and an oil and water sep-
arator and receiver at 23.

After distilling the light oils, the remaining oil
in the still is allowed to flow into still 2 through
pipe 27. In this still the turpentine is distilled

in the usual manner by means of steam. The
distilled turpentine is separated from the water
at 33 and allowed to flow into still 4, where it is
redistilled in order to make it clear. The residue
in stills 2 and 4 is permitted to flow into still 3
by means of pipes 40 and 37, respectively. From
this still heavy oils are recovered by distilla-
tion with- steam, as before, and collected in two
fractions in the separator 46. This separator is
divided into two compartments and the first frac-
tion of the distillate, comprising oils lighter than
water, passes from the pipe 44 into the compart-
ment 49, and the second fraction, consisting of
oils heavier than water, is collected in compart-
ment 50. The water is separated by gravity from
the oils and the oils sent to storage tanks or bar-
relled.

Gilmer's Refining Process The crude material
used in this apparatus is the oil obtained by dis-
tilling pine wood at a low temperature, and is only
impregnated to a slight extent with creosote or
tar vapors.

A combination of the apparatus used is shown in
Fig. 74. At 1 is a receiving tank for the crude
oil and acid water coming from the retort. The
acid water being drawn off, the crude oil is al-
lowed to flow into still 5, where it is mixed with
about 50 per cent of pure water. The mixture is

FIG. 74 GILMER'S REFINING PROCESS.

112

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

heated by means of the steam coil 7, which is
kept under the water so as not to be in contact
with the oil. The distilled oil and water are
condensed in the tubular condenser 13 and are
collected in the tank 20. The residue in the still
5 is thick tar and is sold as such. The mixture
in tank 15 settles by gravity and the water is
drawn off. The oil is then treated with lime water
of about 3 or 4 degrees Baume, in the proportion
of one part of lime water to two of turpentine.
The mixture is then subjected to a thorough
agitation and aeration by blowing air there-
through for about one hour. The mixture is again
allowed to settle and decanted to separate the
lime water. The turpentine is then again distilled
in still 19 in a similar manner as before. To
avoid injuring the product the distillation is per-
formed slowly, about four barrels being distilled
in eight hours. The steam in the close coil
should be at a temperature of about 335 degrees
Fah. The vapors from the second distillation are
condensed by means of the tubular condenser 25
and are collected in a storage tank 28.

Heber's Process The two processes just given
require a specially prepared crude product. In
the Heber process the idea is to purify the bad-
smelling oils produced by destructive distillation
processes by a chemical treatment consisting of
treatment with oxidizing compounds. The process
requires considerable care, as turpentine is also
affected by the chemicals used, and an excess must
therefore be avoided. Before starting the process
the oil should first be removed from the bulk of
the tar by ordinary distillation with steam. This
crude oil containing tarry impurities is then dis-
tilled over lime to remove the remainder of the
tar. A mixture of one to two per cent of lime

\vitb water is used and the distillation carried on
by means of steam. The oil still contains some
coloring and odoriferous matter. To the oil is
added a sufficient quantity of a ten per cent soap
solution to thoroughly dissolve or emulsify the
oil, the whole being mixed in a still provided with
a suitable agitator. When emulsified, a five per
cent solution of permanganate solution holding
from three to five pounds of potassium perman-
ganate and four to six pounds of sulphuric acid of
66 degrees Baume in solution is slowly added,
the mixture being constantly agitated or stirred.
This agitation is continued until the permanganate
solution introduced into the still has completely
lost its color, after whicb by the addition of cal-
cium chloride or zinc sulphate, the soap solution
is precipitated as insoluble calcium or zinc soap.
The turpentine is then distilled in the usual man-
ner by the use of steam.

The oxidizing of the soap emulsion can be ac-
complished by using chromic acid and sulphuric
acid in the same strength and proportions as are
used with the permanganate solution. When -salts
of chromium are used, about six to nine pounds of
potassium bichromate (or an equivalent quantity of
sodium bichromate) should be used for each one
hundred pounds of oil which has been treated with
soap solution. These six to nine pounds of
bichromate are converted into a five per cent
aqueous solution and four to seven pounds of
concentrated sulphuric acid of 66 degrees Baume
slowly added to the same. The treatment is car-
ried on further as with permanganate.

It can be easily understood that if the quantity
of impurities present varied much, there would
be danger of losing turpentine in considerable
quantity.

CHAPTER IX.

GENERAL CONSIDERATIONS FOR THE ESTABLISHMENT OF A PLANT.

To those contemplating the erection of a plant
for wood distillation the several" conditions and
requirements herein contained are essential to suc-
cess, and in special cases other considerations
would be necessary.

The first essential is a supply of raw material
of the proper quality. There must not be any
guess-work about this, but the amount and the
quality of the material should be definitely known
in order to regulate the size of the apparatus.
It is best to own the necessary raw material, but
if not owned it is not best to buy a lot of wood
until the success of the plant is assured. On the
other hand, owners of raw material will be found
to quickly raise the price unless some provision is
made in advance for a sufficient supply. For this
reason, it is better in such cases to obtain an op-
tion at a definite price for a certain period.

To estimate the quantity of material to be found
a simple riding over the land will not suffice.
The wood should be gathered from a certain tract,
cut up and separated into the various qualities,
and these separate portions tested for the amount
of oil. Having determined this, further calcula-
tions can be made as to the expected success of
the venture. Manufacturers of machines claim
anything from a yield of five gallons for sawdust
to fifty gallons for fat wood. Generally these
tests, if made at all, are made upon one stick, or
one lot of wood, and are not safe estimates.

After having satisfactorily determined tb^
amount of raw material, the next point to be
considered is its location. Some of the best wood
for distillation is located in such inaccessible
places that it is not to be considered at all, while,
on the other hand, inferior wood can be obtained
so much more cheaply that it would pay better
to use it. If possible, it is best to have the supply
where it can be reached by both rail and water.
The water route would be cheaper, both for trans-

porting and loading, but it has the disadvantage
in that the wood near the bank has generally
been culled for steamboat purposes and is conse-
quently inferior. With railroad transportation, the
loading is more expensive, although somewhat
compensated for in the unloading. With tram
roads the wood is also apt to be culled. One ad-
vantage in this previous gathering of the wood
is the fact that laborers can be more readily ob-
tained who^ are used to that sort of work, and
probably have teams ready and can haul by con-
tract, thus saving one of the greatest troubles in
the business. A difference of 50 cents per cord
in the cost of raw material will often ruin the
prospects of a plant.

Another important feature is the location of the
plant itself. A steam plant requiring but few re-
pairs and not occupying much space, nor employ-
ing much labor, might be placed directly in the
woods itself, other conditions not being consid-
ered. With a destructive distillation plant, where
the retorts are often out of order, close proximity
to a repair shop would seem advisable. However,
the difficulty of obtaining a few laborers to live
in the woods and stay would seem to indicate that
the proper location of a plant should be sufficient-
ly near a town of some size so that in an emer-
gency laborers could be obtained more easily. An-
other point to be considered in point of location
is the disposition of the product. In this industry,
wagon-hauling won't do like the custom in many
instances practiced in making gum spirits; the
plant must be located on a railroad, and, if pos-
sible, connected with some water route. This is
particularly true with those plants making tar
and charcoal, both of which are bulky articles as
compared with their intrinsic value. Of course, a
junction of two opposing railroads, coupled with
water communication, would be an ideal combina-
tion seldom realized. Furthermore, in making

114

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

charcoal a market for the same must be found
near at hand.

After deciding upon the location, the treatment
of the wood before distillation should be consid-
ered. Wood for this industry should be bought by
weigbt, dry, and the diameter limited to 6 inches.
This is especially true when using knots, as one
cannot tell what the yield will be by the cord, as
wood is of different lengths and sizes and is gen-
erally very crooked; also, the fatter the wood
the heavier it is, and thus more inducement is of-
fered to gatherers to supply the rich wood in pref-
erence. After the wood is delivered, further treat-
ment is generally necessary. In the case of steam
distillation yielding turpentine only, the finer the
material is hogged the better will be the results.
The exact degree of fineness that would be the
most economical can be determined by experience,
and would be dependent upon the difference in
yield in a given time as compared to the cost of
labor and time expended to comminute it.

With the destructive process it is an open ques-
tion whether it is better to use the wood long or
to saw it into short lengths.

The loss in sawdust must be considered, as well
as the labor cost of sawing. The comparison
would have to be made between the yields in a
given time, and the cost of preparation. It is
generally supposed that the resins and products
of distillation exude from the ends of the piece,
so the more pieces there are, there will be twice
as many ends. This is, to a large extent, true,
and it would be supposed that to hog it would
make it infinitely better for distillation. While
this is true as regards the removal of the turpen-
tine, yet when destructive distillation sets in, the
process not only does not work smoothly, but the
material next to the shell of the retort can be thor-
oughly charred and the interior not charred at all.
However, the author finds that, although more
products of decomposition come out at the ends,
yet a considerable portion comes out over the en-
.tire surface. It would be necessary, probably,
to make a definite test at each plant to ascertain
the best conditions.

It may be doubtful sometimes what to use for
fuel, some recommending using the charcoal pro-
duced when a destructive distillation process is
used; others crude oil; some sawdust, and some
wood. Not that which is the cheapest, but that
which is of the least value to the plant should
be used. For instance, charcoal might be made
for $5 per ton, and be cheaper than coal at $8
per ton, but if charcoal could be sold for $10 per
ton it would be of more value to the plant to
sell it than to burn it in preference to coal. In
the same way,. it might cost ?1 per ton to make
the residue from the steam process, and this
would be cheaper than wood as fuel at $2 per ton;
but if the residue could be sold for $3 per ton
for making oxalic acid, then the residue would
be of more value to the plant if sold than if burnt
for fuel. This method of calculation is, of course,
very familiar.

The quantity of fuel used by the different proc-
esses per cord of wood varies with the dryness
and the amount of pitch. Information concerning
this is not easily ascertained. In the hardwood
industry certain facts are definitely known rela-
tive to the fuel used per cord, and for pine wood
it is considerably more. The fuel proposition at
most wood plants is a serious one unless favor-
ably located.

In the steam process distilling sawdust with a
yield of one to three gallons per ton with a dis-
tillation period of one hour, it is claimed by those
making such distillations, that it requires only
about one-quarter of the residue for fuel. This
looks rather low. Using fat wood yielding fifteen
to eighteen gallons per cord, with a distilling
period of three hours, it takes about all the resi-
due as fuel to furnish steam for the operation.

In the steam and distilling process it is claimed
that only one cord of wood is required as fuel for
each cord of wood distilled. One plant, however,
using arches to protect the retort, distilling wood
yielding ten gallons of turpentine to the cord,
with a distilling period of twenty-four hours, took
21/2 cords of slabs to use as fuel to distill the
wood, pump the condensing water and furnish

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

115

lights, etc., and when oil was submitted as fuel
it required 6.4 barrels per cord to furnish the nec-
essary heat for the above purposes. This plant
used cars for drawing out the charcoal.

In the hardwood industry small retorts use
about 500 pounds of soft coal, plus the tar pro-
duced per cord of wood distilled, the coal equal
to about one-half a cord of wood. The large ovens
require from 5,000 to 8,000 cubic feet of natural
gas, 30,000 cubic feet of this being equal, approxi-
mately, to a ton of coal.

From this, it seems that results are apt to vary,
and only a general rule can be given. For the
steam process about one quarter to three-quarters
of a cord of fuel per cord of wood distilled, and for
the destructive process on pine wood from one to
two cords of wood, or its equivalent, according to
the construction of the furnace and the process
used.

The next consideration is the kind and quantity
of apparatus needed, and this is determined by the
process used and the yield per cord; fat wood
taking longer to distill, thus requiring more ap-
paratus for a given caoacity.

Using the steam process for sawdust and slabs,
a plant independent of a saw mill would need
boilers of sufficient capacity to furnish steam for
distilling, pumping water and running the engines
for the conveyors and bog, as well as any stirring
apparatus used in the retort. The size of this
apparatus is determined by the quantity of raw
material to be utilized per day.

With some processes it is best to build in the
form of units, having the units as large as pos-
sible to make economical working. Take, for ex-
ample, a vertical steam retort with an opening at
the top for charging and a door at the bottom for
discharging; it can be readily seen that if all the
work was to be done in one of these, that cases
might arise in which it would take special ma-
chinery to raise and lower the doors, whereas if
made in smaller units they could be easily oper-
ated by hand, or by means of simple contrivances.
Under certain conditions in using a very large re-
tort, by letting in only a small amount of steam,

the whole might condense without doing any work.
Except in those cases where the labor cannot be
used to advantage, it would seem advisable to use
as large retorts and condensers as possible, con-
sistent with continuous working. Where the work
can be performed better in alternate retorts, then
half the size would be better, two units being used.
The steam process, taking from only one to six
hours, has the advantage over the others, in that
a night crew is not necessary.

All steam processes ought to extract the oil
equally well with the same conditions of steaming.
The difference would be in the time of steaming,
and it is to be expected that those processes which
stir the wood would give the quickest and best
yield. For this reason, rotary retorts are in use,
and if the saving in time or increase in yield war-
rants the additional initial cost, they wfii be much
used. But the essential difference in the steam
process must be in the method of handling the
raw material, and an examination of the plans of
the proposed process will enable one to judge of
its merits in this direction. In making estimates
on all plants, plenty of margin should be allowed
for unforeseen contingencies, particularly as to
the yield, the amount of fuel used and the condi-
tion of the market.

If it has been decided tbat charcoal should be
made, then choice should be made of a steam and
destructive process or a destructive process with-
out steam. Perhaps the most important thing to
consider in connection with these processes would
be the method of handling the charcoal produced.
Those processes that arrange for the removal of
the charcoal while the retort is hot are to be pre-
ferred. There is a great saving in fuel, and also
in time.

Ordinary destructive distillation in one cord re-
torts ought to take from twenty-one to twenty-two
hours, thus enabling the contents of each retort
to be distilled once in twenty-four hours. Some
attempt to complete the distillation in less time
than that, but the damage to the retort is very
severe. The use of cars is practiced in ovens and
large retorts, but in order to make them of suf-

116

TEH UTILIZATION OF WOOD WASTE, BY DISTILLATION.

ficient rigidity, it is necessary to make them of
such a thickness that they affect the heating value
of the retort. This can be readily observed In
those cars open at the top and less open at the
bottom. In this case the wood is often found to
be charred at the top of the car and only partially
so at the bottom, and this when the heat is ap-
plied to the bottom.

But when the wood is placed directly in contact
with the walls of the retort, the quality of the tur-
pentine is impaired, so some means should be
devised to keep the wood from coming in contact
with the walls of the retort and at the same time
serve to remove the charcoal. Perhaps more open-
work cars provided with a means of scraping the
trash and fine charcoal from the bottom of the re-
tort upon their exit, may prove satisfactory. On
account of the deposit of coke on the bottom of
the retort, which is the residue from the distilled
tar which drops from the bottom of these open-
work cars, a long retort is difficult to clean out
while hot, and as they must be cleaned to pre-
vent burning of the bottom, the process used must
provide a means for the removal of this material.
The use of large or small retorts is a question at
issue with pine wood distillers. If small retorts
were used cars would not be advisable, as they
occupy relatively too much space, and full advan-
tage of the capacity of the retort cannot be ob-
tained. However, other things being equal, the
author, although preferring small retorts in most
instances, sees no reason why a large retort con-
structed upon the same principles as the long
ovens used in the hardwood industry, and fired by
crude oil or natural gas, would not give as good
satisfaction with pine wood as with hardwood.
Exactly the same principles would govern the fir-
ing, and it would be only necessary to use a cor-
respondingly large quantity of superheated steam
during the first part of the operation to carry off
the turpentine vapors. It would take about 8,000
cubic feet of natural gas per cord to distil the
charge in such an oven. In these cases cars
could be used as found in the hardwood industry.
The use of an oven brings forth the question

of furnace construction and the cost of fuel. There
is no doubt that the cost Of charring in cars is
greater than without their use, but the question
of using an arch to protect the retorts from the
injurious action of the fire gases is much agitated.
II has been found at a steam and destructive dis-
tillation plant using retorts seventeen feet long,
set in a furnace with return flues, that if prop-
erly made the furnace arches stood very well, but
if they became out of order for any reason they
would fall in at the most critical periods of the
distillation and allow the flame to severely injure
the retort. Furthermore, the fuel used was over
twice as much as is usually used when no arch
is present. Firing with crude oil over six barrels
was necessary to distill one cord of medium rich
wood, when without an arch one cord of wood
would be sufficient. It would seem that with short
retorts the use of the arches below the retort
causes the heat to go up the chimney, whereas in
a long oven the heat of the fuel would be better
absorbed by the brickwork, owing to the longer
time of contact. It is on this account, probably,
that arches are found under some of the 50-foot
ovens used in the hardwood industry, and none
under the 9-foot cylindrical retorts. It would
seem that in the latter case the retorts would
rapidly burn through, but this seems to depend
upon the firing, as a Florida company has used
some for three years and a Northern hardwood
company used some continuously for five years,
and only one out of seven had needed to be even
turned in that time. On the other hand, at the
game place a whole set had been burned out in
less than a year. As an oven is so difficult to
replace, it is advisable to protect them to some
extent. An arch as long as it stands and is not
in direct contact with the iron of a retort will
undoubtedly protect the retort, and in those -cases
where the fuel is cheap enough to allow it, the
arch could be advantageously used.

The next feature to consider in judging the
process for the production of turpentine, tar and
charcoal is the quality of the turpentine pro-
duced. Although the refining of the crude prod-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

117

net is perhaps the most essential thing, connected
with the quality of the oil produced, nevertheless
those processes that do not take off the turpen-
tine before destructive distillation begins and col-
lects it in a separate receiver, are obviously at a
disadvantage as far as quality is concerned. When
rosin in distilled rosin spirit is produced, and
this is usually found in the turpentine produced
when the receiver is not changed, consequently
this turpentine is not as good as it would be if it
did not contain this substance. If th-is kind of oil
can be sold at the same price as better qualities,
and it has been so far, then, of course, it is not
desirable to separate the rosin spirit; but the
time is coming when only the pure terpene can be
sold at a high price, while the mixtures must be
sold for less.

At the present time it is necessary to have a
colorless, agreeable smelling oil, and this should
bo sought for.

Special processes can be judged by their claims,
and these are given in connection with the process.

Extraction processes might be made to pay after
the market is established, but their final success
will depend largely upon the demand for the rosin
and rosin oil.

Market Conditions. The most important prob-
lem connected with the distillation of pine and fir
wood is the disposal of the products. If interested
parties would spend their money advertising wood
turpentine, instead of augmenting the patent of-
fice receipts by obtaining useless patents, much
more could be done toward solving the problem at
hand. There are plenty of good processes, and
they will yield a product of the finest quality if
handled right.

A great deal has been written about the ignor-
ance of the men who produce wood turpentine,
but far more could be written of the ignorance of
consumers and buyers. A sample of nearly chem-
ically pure pinene was sent to a buyer of a lead-
ing varnish company, and the sample returned as
not satisfactory. Instead of testing the oil, the
cork was removed and judgment passed on the

odor. This oil could not be duplicated at less than
twice the price of ordinary turpentine.

Complaints are made concerning the variation
in quality, but there is also a variation in the qual-
ity of gum spirits. By having storage tanks of
sufficient size, a. standard grade from each plant
can be readily obtained. But what is the use of
making a very good quality of turpentine when it
does not command any better price than an in-
ferior quality? Thousands of gallons of slightly
yellow oil have been sold which would have been
refined if the price had warranted it. Only so
much could be obtained for it, good or bad. With
a standard grade made by some of the methods
herein given, the large varnish and paint houses
can be easily convinced of the merits of this tur-
pentine. The painter is the most difficult to per-
suade; the least variation in the odor at once
makes him suspicious. One painter using wood
turpentine painted a house with white lead and
added a Japan dryer containing some sulphuric acid
so that the paint would dry quickly. The dirty
looking house produced was laid to the turpentine,
instead of the wrong kind of dryer.

The consideration of the market for turpentine
needs no further illustrating than the fact that
Chicago paint manufacturers are using thousands
of gallons of it, and claim that it works better.
However, there is ho indication of their being
willing to pay the market price for it. On the
other hand, varnish makers have not found a
wood turpentine but what it varies too much to
suit their requirements.

What applies to the turpentine market also ap-
plies to the tar market. Here tkwre is more ex-
cuse for complaint, for the retort tar is not al-
ways as good as it might be. With a little care,
so that the resinous and oily products will be left
in the tar, this product could be made of a qual-
ity satisfactory to cordage manufacturers. It
should be sold more by viscosity than it is, as
some tar of the required specific gravity is really
too thin.

The market for tar is limited, but with the
prominence now being given to steam processes,

118

THE UTILIZATION OF WOOD WASTE BY DISTILLATION,

the supply is apt to be lessened, thus causing
a prospect of a better price.

With charcoal the market is entirely local, al-
though some sell to blast furnaces at a distance.
The price of charcoal is easily ascertained, but the
consumption cannot be easily determined.

A comparison of the cost of operating by the
various processes will be given below. Different
values can be substituted to suit the special con-
ditions, the ones given below being only approxi-
mate. In the steam process using sawdust a value
must be placed on the residue used for fuel, as
in many cases this could be sold. A steam plant
uses so much more wood in a given time that a
given supply would be much sooner exhausted than
with a destructive distillation plant. It is not nec-
essary to operate a steam plant at night, as a dis-
tillation can be completed in three hours, but it
is necessary to operate at night with a destructive
distillation process, as it takes about twenty-two
hours. In twenty-four hours a steam plant ought
to distill eight times as much wood.
Steam Plant.

Plant and equipment $25,000

Depreciation on retorts only 10% $1,200

Interest at 6% 1,500

Operating expense

Depreciation and interest, per month.. $ 233

2080 cords wood at $3 6,240

Labor and superintendence, $1 per cord 2,080

Total expense per month $8.553

Expense per cord. $4.112.

Twelve Hour Basis.

Operating expense

Depreciation and interest, per month.. $ 233

1040 cords wood at $3 3,120

Labor and superintendence at $1... 1.040

Total per month $4,393

Expenses per cord, $4.224.

Destructive Process.

Plant and equipment $25,000

Depreciation on retorts 20% $2,400

Interest at 6% 1.500

Operating expense

Depreciation and interest, per month $ 325

260 cords wood at $3 780

Labor, etc 450

260 cords fuel at $2 520 . .

Yields per Cord.

RICH WOOD. LEAN WOOD.

15 gal. turpentine at 5 gal. turpentine at

50c $7.50 50c $2.50

10 gal. wood oil at 20c 2.00 3 gal. wood oil at 20c .60

90 gal. tar at 6c 5.40 50 gal. tar at 6c 3.fiO

46 bu. charcoal at lOc 4.60 46 bu. charcoal at lOc 4.60

$19.50
Expense destructive.. 7.98

$10.70
7.98

Profit per cord $11.52 2.72

The steam process obtains turpentine only, so
the figures would be:

Rich Wood.

Yield $7.50

Expense 24 hours 4.112

Lean Wood.
$2.50
4.112

$2.075

Expense per cord, $7.98.

Profit per cord $3.388 Loss ner cord $1.612

On a yearly basis of 250 days.

Steam Process 24 Hours.

Fat Wood, Profit. Lean Wood. Loss.

20.000 cords at $3. 388. $67, 760 20,000 cords at $1.612. $32, 240

Profit on $25,000 271% Loss on $25,000 128.96%

12 Hours.

10.000 cords at $3. 276. $32. 760 10,000 cords at $1.50. .$15.000
Profit on $25,000 131% Loss on $25,000 60%

There would be considerable difficulty in ob-
taining 20,000 cords of wood at $3 per cord.

Destructive Process.

Fat Wood. Profit. Lean Wood, Profit.
2500 cords at $11. 52. $28, 800 2500 cords at $2.72. . .$6,800
Profit on $25.000 114.2% Profit on $25,000 27.2%

Figures for a rotary retort will not be put down
here, as they have not been even aproximated with
this apparatus.

From the above, it can be seen that the steam
process gives greater returns on fat wood than
the destructive process in the same length of
time. With lean wood the reverse is apparently
true, and an actual loss might be expected in
some cases. The apparently wonderful returns
from the destructive process is due to setting the
market value on products of a similar nature.
However, although prospectuses relative to these
plants put down these values, unfortunately, the
market conditions are such that often these prod-
ucts cannot be disposed of at any price. This
has been particularly true of wood oil until re-
cently, when it has been disposed of to some ex-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

119

tent in creosote paints. The charcoal is often not
sold at all, or for only half the values assigned to
it. At one plant, however, the prices above given
have been obtained in limited quantities.

It can be seen that this problem of wood dis-
tillation is not so simple as it appears at first
sight. This accounts probably for the number of
patent processes that apparently solve the prob-
lem. Upon further investigation and the expendi-
ture of considerable money, these processes, which
start out so fairly, prove, in most cases, to be dis-
mal failures. Instead of building plants on a com-
mercial basis at the start, more experimenting
should be done on a small scale until all the par-
ticular points in a given locality have been con-
sidered, then a plant should be built in units,
making one unit pay before building the next, and
so on until the limit is reached.

It has been found that the profits of this indus-
try, as shown on paper before the plant is built,
are far greater than the actual working results, and
in many cases the loss is greater than the figured
profit was expected to be.

Owing to the wide difference in proportion be-
tween the percentages of resinous products in dif-
ferent trees and in different localities
many instances will be found where it is not pos-
sible to operate plants of this kind successfully.
The variations in the yields from a cord of dif-
ferent pines and firs will be found in the next
chapter.

Of the two processes, steam and destructive dis-
tillation, the former is probably better for fat wood
and for cheap wood, such as sawdust. With wood
yielding small amounts of turpentine, the steam
process would not yield enough product to pay for
the gathering of the wood, unless some use is
found for the residue. Using the destructive proc-
ess, with a good demand for tar and charcoal, it
might be possible to use such a class of wood suc-
cessfully. The greatest advantage of a success-
ful destructive distillation process would be that
it takes so much less wood to obtain products of
the same value. With the steam process a given
supply of wood is too soon exhausted.

CHAPTER X.

COMPOSITION OF WOOD AND PRODUCTS OF DISTILLATION.

Pine wood has a structure very similar to other
kinds of wood, but substances peculiar to the pine
family are also to be found.

Generally considered, pine wood consists of cel-
lulose or woody tissue, containing gums, resins,
salts, sap, etc., and the outer bark. When wood is
spoken of, it immediately suggests lumber or fuel,
but the uses of wood in other lines will be found
to be very many.

The woody fibre consists primarily of two sub-
stances, cellulose and lignin, the first having the
formula n (Ce Hio Os) ; 100 parts containing 44.45
parts carbon, C.17 parts of hydrogen and 49.38 of
oxygen. There is also in wood recently cut a .
large percentage of water, amounting in some
cases to as much as 45 per cent. Air-dried wood
generally has about 20 per cent moisture. All this
can be evaporated from the wood by heating it at
105 degrees to 110 degrees C. for a sufficient length
of time, but it will reabsorb practically the same
amount when again exposed to the air. Very fat
pine contains less than 10 per cent moisture.

Pine wood has a specific gravity of from 0.55 to
about 1.15, being in the latter case very fat or
pitchy. Usually the fat wood is harder than the
other and does not decay so rapidly.

The composition of nearly all kinds of wood is
relatively the same, provided they be dry and con-
tain no large amount of resins and gums. This
average is 49.70 per cent carbon, 6.06 per cent hy-
drogen, 41.30 per cent oxygen, 1.05 per cent nitro-
gen and 1.80 per cent ash. This, of course, would
not apply to fat pine. By extracting the resin, the
fibre left would be nearer to the above composition
than the original wood.

The most important part of pine wood to a dis-
tiller is the resin. This contains the turpentine
and the more resin, the more oil and tar. In the
pines the resin fills in the space between the cells.

In other woods water is found in the porous part,
but in the pine the resin takes the place of this
water to a large extent. It is difficult to deter-
mine the amount of water in fat pine on account
of the turpentine evaporating with the water when
the wood is heated.

The resin seems to be of two kinds, that con-
tained in the heart wood and that contained in the
sap. Although the exact physiology of the forma-
tion of resin in a tree is not known, it is gener-
ally supposed to be due to the infiltration of the
sap resin into the heart wood of the tree. This
resin loses its fluidity and is not drawn out by tap-
ping the tree. The difference in the odor of the
turpentine produced from the tapped tree and that
produced by distilling the wood itself is probably
due to the odors of the different impurities in these
oils, .coming from the different resins. Special
investigations by the Forest Service have shown
that the distribution of resin throughout the tree
from top to bottom follows no law, the larger
amounts being found as often in the top or middle
portions as in the butt-logs. Nevertheless the im-
pression prevails that there is more resin in the
stump and this impression seems to have sufficient
basis to be a fact.

The cause of the formation of resin in the pine
is not easy to explain; resin passages arise from
the shrinking away from each other of the walls
of neighboring rows of cells, an intercellular space
being thus formed and gradually filling up with
products of decomposition and secretion which is
called resin. These resin passages are found even
during germination and continue to form until the
tree dies. It is claimed that this formation con-
tinues after the death of the tree, an example be-
ing given of the change of old stumps into light
wood. It may be that after the tree is cut down,
the sap rises each year and remains in the wood

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

121

and finally when the roots die, this resinification
ceases. It takes so long for a stump to decay that
the evidence of the presence of additional resin
after death could not be well proven unless the
stump was specially marked at the time the tree
was cut.

According to the evidence of Prof. Tschirch, of
Switzerland, who has made recent investigations
of the causes of resin secretion, the seat of resin
secretion is in a mucilaginous layer lining the in-
ner walls of the resin ducts. These ducts are
present in the untapped tree, but many more of
a secondary nature are formed when the tree is
tapped. The latter effect seems to be an effort
of nature to heal the wound. This evidently shows
that the production of resin during the life of the
tree is not a product of resolution.

If the resin is formed by the decomposition of
the cellulose and starch while the tree is growing,
the production of hydrocarbons from carbohydrates
by a change in cell growth is demonstrated, as
well as the production of the compounds found in
the tar, 'by means of the destructive action of heat.

On the application of a moderate heat to the
wood, this resin exudes. Considerable heat is nec-
essary to draw all the resin on account of the
capillary attraction of the woody fibre. If the
heat is sufficiently increased or steam added, the
turpentine will distill from the resin, and if the
heat be further increased, the resin itself will dis-
till. When not very hot, the resin will hold the
turpentine, which can be removed by a subsequent
distillation with steam or direct heat.

This resin contains turpentine, some pine oil,
resin oil and rosin. It is soluble in ether, alcohol,
carbon bisulphide, etc. Alkalies unite with it to
form partially soluble compounds. Strong acids
decompose it. Upon destructive distillation the
turpentine and other oils distill and the rosin is
decomposed into rosin spirit, rosin oil, gas and
pitch. The specific gravity varies from .8 to 1.15.

After the resin is removed from wood, w^iat is
left is mostly woody fibre, consisting chiefly of
cellulose.

To obtain cellulose pure from the woody fibre,

it is necessary to treat the wood with various solv-
ents such as ether, alcohol, dilute acid and alkali
and finally wash with water. Cellulose is a carbo-
hydrate and thus in this respect is similar to starch
and sugar and although it cannot be converted into
starch it may be changed into sugar. This feature
is interesting as it is possible to make ethyl alco-
hol from the sugar produced.

Acids and alkalies affect cellulose; hydrochloric
acid forms hydro-cellulose and wood sugar, nitric
acid produces nitro-cellulose and other products of
oxidation according to the strength of the acid
used. Strong solutions of alkalies affect it; caus-
tic soda being used to mercerize cotton, while
melted caustic alkalies change it into oxalic acid,
this being another important reaction of particu-
lar value in treating sawdust. A mixture of cup-
ric oxide and ammonia known as Schweitzer's re-
agent, dissolves cellulose, and the addition of acid
to this solution causes a flaky precipitate.

Viscose is a compound of cellulose formed by
treating calico (cotton) with strong soda or pot-
ash and washing with alcohol. These compounds
treated with carbon bisulphide C 82 form thio-
carbonates which are soluble in water. The vis-
cous solution of these thiocarbonates is called vis-
cose.

To the distiller, the most interesting feature con-
nected with the treatment of wood is its decompo-
sition by means of heat. The main products pro-
duced are pyroligneous acid, gas and resinous prod-
ucts, wood alcohol, wood oil or red oil, tar, and
charcoal.

Below is given a list of the various substances
that may be expected from destructive distillation
of pine wood containing resin. This list will ex-
plain why refining some of the products might be
expected to be difficult. Charcoal is the residue.

Gases.

Carbondioxide, carbon monoxide, .hydrogen, me-
thane, acetylene, ethylene, propylene, butylene, pen-
tine, benzol.

Wood Oil and Tar.

Benzol, toluol, xylol, styrolene, naphthalene, re-

122

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

tene, paraffine, dimethyl ethers of pyrogallic acid,
methyl pyrogallic acid and propylpyrogallic acid,
phenol, the three creosols, the xylenols (1, 3, 4 and
1, 3, 5) phloral, pyrocatechin, orthoethyl phenol,
guaiacol, pyrogenous resins, pinene, sylvestrene,
dipentene, amylene, hexylene, pentane, toluene hex-
ahydride, toluene tetrahydride, xylene hexahydride,
xylene tetrahydride, xylene, cumene hexahydride,
cumene tetrahydride, cumene, terebenthene, cy-
mene hexahydride, metiso-cymene, metapropyl-
ethyl benzene, dioctene, diterebentyl, diterebenty-
lene, didecene,, propionic aldehyde, furfural and
methyl, furfural, methylfurfural, dimethylfurfurane,
trimethyl furfurane, pyroxanthine.

Wood Vinegar and Wood Alcohol.

Furfural, formic acid, acetic acid, propionic acid,
butyric, valerianic, capronic, crotonic, angelicic and
caproic acids, valerolactone, pyrocatechol, methyl
alcohol, methyl acetate, acetone, methyl formate,
methylethylketone, allyl alcohol, dimethyl ace-
tate, acetic aldehyde, methylamine, ethyl alcohol,
hydrocoerulignon, allyl alcohol, isobutyl alcohol,
isoamyl alcohol, methylpropylketone, ketopenta-
methylene or cyclopentanone or odipic ketone, ke-
tohexamethylene or pimelic ketone. Alpha-
methyl-Beta-ketopentamethenylene, pyridine, methyl
pyridine, valeraldehyde, allyl alcohol and water.

Residue.

Charcoal, containing carbon, hydrogen and oxy-
gen and mineral matter.

When wood is first heated in a retort, only water
and a little furfural are driven off until the tem-
perature reaches 150 degrees C. With fat pine,
some oil also comes over. As the temperature ap-
proaches 160 degrees C. decomposition sets in, the
entire loss in weight of the wood from 150 degrees
to ICO degrees being only about 2 per cent, most of
which is water. This latter temperature corre-
sponds to about 320 degrees Fah.

The following table shows, according to Violette's
tests, the relative percentage loss at the different
temperatures:

Temp. C 150 150-160 160-170 170-180

Loss per cent, water only 2 5.5 11.4

150-280 280-350 150-430 430-1500
63.8 6.5 81. 1.7

At first only a small amount of acetic acid comes
over, but the percentage increases gradually until
the temperature reaches about 280 degrees C.,
when the proportion of acetic acid diminishes. At
a temperature of about 325 degrees C. (617 degrees
Fah.) a sudden formation of gas takes place and
the temperature increases rapidly to 375 degrees
C. (707 degrees Fah.), the extra heat being caused
by the decomposition of the wood.

When the temperature reaches about 430 degrees
C (806 degrees Fah.) most of the volatile matter is
distilled and only charcoal remains in the retort.
With some woods containing large amounts of par-
affines, they are not distilled under 535 degrees C.
(998 degrees Fah.).

Why cellulose breaks into so many different
products when distilled, it is difficult to state. The
molecule is very complex, and it is probably on
account of the large number of atoms.

An explanation of the process is given by Mills,
in his use of the term cumulative resolution. In-
stances of this are very common in inorganic chem-
istry, one example of which he gives in the case
of manganese dioxide splitting up when heated into
trimanganic tetroxide and oxygen according to the
following:

3 Mn O 2 = Mn 3 O* + O 2 .

With woody fibre, water instead of oxygen is
lost, and new products formed. As the temperature
increases more water leaves. The following is
Mill's illustration:

Cellulose Alcoholoids.

Ca Hio Os
Ca Hs C>4

Ce Ha O s

Ca H* O.

C H 2 O

Extreme Accumulation.
Ce H 8 O*
C H 8 O 3

Ca H t O 2

C. H 2 O
C.

It will be noticed that each product is formed by

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

123

the loss of one molecule of water, H= O, from the
compound above it.

Although this may be the mode of decomposition,
the final results would be better expressed approx-
imately as occurring as follows:
C H,o Os = 3C + 4 H 2 O + Cs H 2 O
Wood Carbon Water Gas and Tar

100 22.2 44.5 33.3

From the gas formed something can be deter-
mined in regard to the progress of the distilla-
tion. When large proportions of oxygen are pres-
ent, as in the early stages, an abundance of car-
bon dioxide C O is found in the gas; later, car-
bon monoxide C O is found, and finally the heavier
hydrocarbons and hydrogen. The presence of
hydrogen is probably due to the degrading of the
hydrocarbons while hot.

Methane, C H4 loses hydrogen and becomes by
equation

2 C H = C 2 H 2 + H.
and when very greatly heated

C H* = C + H 4

In a similar manner the formation of some of
the other hydrocarbons found in the gaseous prod-
ucts may have been produced according to the
following reactions:

3 Cfe H* = 2 Ct H. + 2 C H
Ethylene Acetylene Methane

4 CL H< = 2 C 2 H 2 + 3 C H* + C
Ethylene Acetylene Methane Carbon
2 C H 4 + CO = C 3 H 8 + H 2 Q
Ethylene Carbon Oxide Propylene Water

10 CH* = Cio H 8 + H 32
Methane Naphthalin Hydrogen
The presence of acetic acid in the distillate is
supposed to be due chiefly, and the methyl alcohol
wholly, to the decomposition of the vascular matter,
and not of the cellulose. The properties of the
many products of distillation cannot be given here,
as only a few are of sufficient importance. A de-
scription of only the most valuable will be given.

Turpentine.

Oil of turpentine obtained from the gum of live
trees and spoken of as gum turpentine or orchard

turpentine, has a general formula of Cio H t . It is
comprised of a mixture of two or more terpenes,
all having the same empirical formula, but varying
In their constitutional or graphic formula, accord-
ing to the method of bonding between the carbon
atoms.

This oil should be a water white, light refracting
liquid of 0.8620 to 0.8720 sp. gr. and distilling be-
tween 156 degrees and 170 degrees C. It is very
soluble in ether, absolute alcohol, carbon bisulphide,
essential oils, fatty oils, benzine, acetic acid, gaso-
line, chloroform, etc. It is only slightly soluble in
water and glycerine. It oxidizes very readily to
form a thick oil and becomes "fat" and has an acid
reaction.

Some grades upon vaporizing increase in volume
193 times, absorbing as latent heat 74 cal. per gram.
The vapor density air=l is 5.0130. Flash point
8994 degrees F. Sp. heat .472 boiling point 155
160 degrees C.

The uses of turpentine are quite well known. In
addition to its use in medicine, it is used in paints,
varnish, sealing wax, shoe blacking, etc. The three
kinds of turpentine usually considered are Ameri-
can, French and Russian, the French oil being levo
rotary and the other two dextrorotary.

Terpenes are classified according to their power
of absorbing bromine. Some absorb two and some
four atoms of bromine. Some do not combine with
bromine at all. This variation is supposed to be
due to the different ethylenic Unkings. There are
not as many different terpenes as was formerly
supposed, but there are a large number of hemi-
terpenes, sesquiterpenes and polyterpenes.

In the oil from the gum the chief constituent
seems to be pinene. There are three modifications
of this, varying according to their action on polar-
ized light. In American and English turpentine
these rays are deflected to the right and the oil
is said to be dextrorotary. In the French oil it
is laevorotary. An inactive form is also found.
American oil of turpentine contains both, the dex-
tro-rotary being in excess.

This specific rotary power is determined by
means of an instrument called a polariscope, the

124

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

action of which can be learned by referring to treat-
ises on chemistry and light.

Another feature of the terpenes is their power
to refract light. An example of refraction is giv-
en when one end of a stick is inserted in water.
The apparent bending of the stick is due to the
different degrees to which the light from the stick
is affected by water and air. The refraction is
measured by the trigonometrical relationship of
the refracting angles. This is done by means of
some form of refractometer. It is spoken of as
the refractive index. The working of this instru-
ment (the refractometer) can be found described
in works on oils and fats and on light.

The specific rotatory power of orchard turpentine
is given as being anywhere from [a] D = 3
to + 20, and the index of refraction N D = 1.4682
to 1.4737 at 20 degrees C.

Pinene.

On account of the difficulty of separating the
different kinds of pinene, some of the constants
given are uncertain.

The boiling point is 155 degrees to 156 degrees C.
and the sp. gr. at 20 degrees C. 0.858 to 0.860.
Kannonikow gives as the specific rotatory power of
pinene as to] D = + 32 degrees for the dextro
and 43.4 degrees for the laevo at 21 degrees C.
Rolfe gives [c] D + 45.04 and 44.95. The in-
dex of refraction at 21 degrees is N D 1.46553.

And Bredt the following:

Wallach considers that pinene has an intercalary
linking and ascribes to it the formula below, which
equals Cio Hi.

c -c

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

125

Dipentene.

When pinene is heated to 250 degrees to 270 de-
grees C., it is converted into dipentene. This sub-
stance is inactive to polarized light. Its boiling
point is 175 8 degrees C. The sp. gr. at 20 degrees
C. is 0.845 and the refractive index N D = 1.47308.
One form prepared from caoutchouc boils at 175
degrees to 176 degrees C., and sp. gr. 0.844, and.
the refractive index N D = 1.47194 at 20 degrees.
This is a very common form of terpene and is
found in many oils.

Sylvestrene.

This is found in Russian turpentine oil. It has
a very agreeable odor similar to lemons and also
to the oil of bergamot. It boils at 175 degrees to
17G degrees C., has the sp, gr. of 0.8480 at 20 de-
grees C., and the refractive index N D = 1.47573,
with a specific rotatory power [] D = ~U 66.32.

The characteristic reaction of sylvestrene is
shown by adding one drop of concentrated sulphuric
acid to a drop of sylvestrene in acetic anhydride,
when a' blue color is produced. Another terpene,
carvestrene, shows the same reaction. This may

The question is, what oil is obtained when pine
wood is distilled with steam or direct heat? There
seems to be but little doubt that it is a terpene of
the formula do Hi. The oil produced by steaming
and by destructive distillation is different in some
respects, and is due to the fact that the latter con-
tains oils coming from the decomposition of the
rosin. When wood is destructively distilled and
the products of decomposition are all collected
in the same receiver this rosin spirit and also wood
oil are to be found in the distillate and cannot be
satisfactorily separated.

The oil produced without decomposition of the
v/ood gives the tests for pinene, forming a solid
hydrochloride with dry hydrochloric acid gas, and
having similar constants. In many cases, samples
of wood turpentine show more pinene than orchard
turpentine. On the other hand, bad smelling colored
wood turpentine shows tests for other oils.

Tests of fir terpene produced by distillation of
the Douglas fir by means of steam and direct heat
are as follows, determined at the University of
Minnesota:

be inactive sylvestrene. Temp - 20 d
Specific Gravi
The other terpenes of importance will be found

Boiling- point

in the following table. The temperatures given index of refrt
are in degrees Celsius: Spec. Rot. P<

degrees C. Steam.

ty 8621

Destructive.
.8662
6 . 157-160
1.47246
29.4

(degrees) C 153.5-15'
iction 1.47299

jwer 47.2

Terpene.

Solid
or Modifica-
Liquid. , tions.
3

Boiling
Point.
155-156
160-161
155-156
175-176
175-176
175-176
178
185-190
170
179-181
170-172
173
175-178
161-165
153
149-150
162-170

Specific
Gravity.
0.858-0.860
0.842-0.850
0.867
0.846
0.844
0.848

Temp.
20
54-48
20
20
20
20

22
18

Specific Rotatory
Power [<J]D Temp.
+45.08 and 44.95 21
and SO. 61 54
and 6.46 20
+106.8 and 105.0 20
Inactive
+66.32
Inactive
Inactive
+60.33 and -17.64 19

Index
of Re-
fraction.
1.46553
1.45140
1.46900
1.47459
1.47194
1.47573

1.48800
1.48458
1.47145
1.46010
1.47439

1.46600

Tom p.
21
54

20
20
20
20

19
20
28
18
20

. S 3

... 1

Sylvestrene

Carvestrene

Terpinolene . . . -.

Phellandrene ... .

0.847
0.847
0.836
0.823
0.842

Terpinene

Thujene

, 2

Svnthetical Terpene..

Fenchelene

Euterpene

Tricyclene

. S 1

Bornylene

,. S 1

Sabinene .

0.840

126

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

Another terpene from the Norway pine investi-
gated at the same university gave

Temp. 20 degrees C. Steam. Destructive.

Specific Gravity S636 . 8666

Boiling point (degrees) C... 153-154 158-160

Index of refraction 1.47127 1.47160

Specific Rot. Power +17.39 +7.56

Wood terpene from different samples of oil from
yellow pine :

1 2345

Specific Gravity... 0.865-0. 867 0.862 0.862 0.863 0.864
Boiling point C... 155-157 159 156 158 156

The author made the following tests on samples
of oil. One marked white oil is a wood turp, the
two off-color oils were later distillates from the
same charge from which the white oil was ob-
tained. The other two were made from sawdust
and fat wood. These two oils were very clear and
white and apparently well refined, and had
a strong odor of sawdust.

For fuller description of the terpenes see some
special work under that head.

Pine Oil.

This name is applied to wood turpentine and
also to a compound to which is given the formula
C-M Hio. This latter is supposed to be formed when
pine wood is distilled at about 400 degrees C. (Pat.
L. Pradon, May 1, 1883). Another so-called pine,
oil is produced, as stated in Clark's patent, previ-
ously described, at 240 degrees to 300 degrees Fah.,
and is a product of the destructive distillation of
the wood. The term pine oil is also applied to all
the oily products of the pine collectively. Rosin
spirit is sometimes called pine oil.

Resin Oil.

It has been stated that the resin contains tur-
pentine, pine oil (?) resin oil and rosin. After
the turpentine is removed from the resinous crude

>ff-Color.

-Sawdust-

Temperature.
Specific Gravity 20/20

White Oil.
0.8654

Orchard Turp.
0.8668

0.871

0.888

0.8762 21/21

2
0.890

Boiling point (degrees^ C..
Index of refraction

156.5

1.4721

158.25
1.4732

159
1.4715

157
1.4748

160
1.4748

167
1.47820

Spec. Rot. Power

+17.91

+17.53

+17.77

17.15

+16.83

+8.99

Flash Point C

Distilling under 165V& . ..

88 50

91 00

85.00

32.78

Although the tests here given do not prove that
this oil is pinene, the production of a solid hydro-
chloride of the formula Cio His H Cl may be con-
sidered to be a partial proof, and this has been
done. Also terpin hydrate has been made from
this oil.

The preparation of pinennitroso chloride and
pinennitrol piperidin from this oil, as well as oth-
er compounds, ought to be as confirmatory a test
as would apply to pinene from gum spirits.

As has. been noticed in many instances, the oil
from destructive distillation varies greatly from
that of the steam process, and is probably due to
the presence of rosin spirit and wood oil.

turpentine obtained by distilling the wood, a thick,
slightly yellow oil comes over. Although the oil
is well known, no distinctive name is given to it,
nor is its chemical composition known. It may be
the intermediate compound between turpentine and
rosin and consequently be found to contain oxygen.
It might be supposed that this compound would be
pinole hydrate, mixed with oily matter, this pinole

H
hydrate being the same as sobrerol Cio Hi 8 O

produced by exposing oil of turpentine to the
action of moist oxygen in the sunlight.

However, an investigation made at the Massa-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

127

chusetts Institute of Technology seemed to indi-
cate that it was more of the nature of turpineol.
Turpineol seems to be an alcohol Cio H ]7 OH, and
several different compounds go by that name. One
form boils at 215 degrees to 218 degrees C., and
if it contained a small amount of turpentine it
might be expected to boil at a lower temperature.
In the investigation above mentioned, the yellow
.cil was submitted to a fractional distillation. Al-
most the entire amount boiled between 200 214
degrees C. The fraction 209 211 constituted fully
GO per cent of the whole, and was apparently a
homogeneous substance. When the oil was diluted
with alcohol, saturated with dry HC1 gas, and
cooled, it solidified to a mass of 'white crystals,
melting at 50 degrees C. The indications are that
ii, is terpineol.

Rosin.

The substance left after distilling the turpentine
oil from crude gum turpentine is called rosin or
colophony. This substance is also produced by
carefully boiling down the resin drawn from heart- '
wood by heat. This latter is not as good as the
gum rosin, as it is colored too deeply.

Rosin is very brittle, melts at 100 degrees to 140
degrees C., and has a specific gravity of about 1.075.
Alkalies convert it into a deliquescent and soluble
soap called "rosin soap." It consists of abietic
anhydride and abietic acid. Some consider it a
mixture of hydric pinate and sylvate and consider
that rosin may be an oxidation product of turpen-
tine, as follows:

4Cio H + SO.. = 2Cso Hso D + 2H 2 O

Whether the oil is formed from the rosin or
the rosin from the oil is not definitely known.

The oleo-resin from which ordinary rosin is pro-
duced is considered by Tschirch & Koritzschoner
to consist of the following ingredients:

Palabienic acid C 13 HZO O 2
Palabietic acid CM H 30 O 2
A and B Palabietiolic acid Ci 8
Spirits of turpentine
Paloresene

, . 6%
2 .............. 56%

20%
10%
Impurities, bitter principles and water ........... 3%

Upon distillation only the oils pass over, and
it would be expected the other products would re-
main behind practically unchanged. It doesn't
seem advisable to give any definite composition to
pine products as now produced, for not even the
turpentine itself is of stable composition.

The distillation of the gum turpentine is per-
formed in copper stills heated by a direct fire, hot
water being added to the still from time to time
in small quantities. Steam would probably be bet-
ter. The temperature of the distillation is much
reduced, but does not follow exactly the laws gov-
erning the distillation of two immiscible liquids.
The temperature of distillation of oil of turpentine
with steam when both vapors are saturated is less
than 100 degrees C. After the oil is removed, the
cap is taken off the still and the excess water
boiled off and hot rosin run off through a cotton
filter into a trough, from which it is dipped into
barrels.

Rosin is stable at 150 degrees C., distillation tak-
ing place at a higher temperature (250-300 degrees).
Rosin spirit or pinoline, rosin oil, gas and coke or
pitch are the products of decomposition. When
distilled in a vacuo or by means of superheated
steam, very little decomposition takes place. Ros-
in can be separated from mineral oils by treating
with acetone; the rosin being soluble and the min-
eral oils not.

Rosin Spirit.

As this substance is to be found in oil of tur-
pentine produced by destructive distillation, some
of its properties will be described here.

Rosin spirit is a very complex body produced by
the destructive distillation of rosin. It boils be-
low 250 degrees C. (78 to 250 degrees), and resem-
bles oil of turpentine, for which it is sometimes
substituted. It is now often called naphtha and
amounts to about 3 per cent of the rosin charge.
The spirit is found to contain a mixture of hydro-
carbons and oxygenated bodies.

Professor Mills has made an examination of rosin
spirit. He states that "a fraction from the spirit
boiling pretty constantly at 154-156 degrees had

128

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

^flP^ic

^P rec

^ Dill

the sp. gr. .852 at 14.4 degrees C., and almost ex-
actly the composition of turpinol (Cio H)2 EL O.
The turpinol of Wiggers and List is said to have
the sp, gr. .852 and boil at 168 degrees C. Their
product gives a crystalline hydrochloride CioHi 8 2HCl,
but rosin turpinol does not appear to do so, and is
certainly not identical with ordinary turpinol. When
rosin turpinol is treated with strong oil of vitriol,
it yields a liquid having the odor of terebene.
When treated with bromide, it furnishes an oily
product, containing from 31 to 43 per cent of the
reagent; chlorine is similarly taken up to the ex-
tent of 50 per cent; hydric chloride to the extent
of 18 to 19 per cent. Another fraction, boiling at
188 degrees to 193 degrees and dried over sodium,
agreed in composition very closely with turpentine,
but it could not be made to yield a solid hydro-
chloride."

Renard gives a list of light hydrocarbons' with
low boiling point that are to be found in rosin spirit
and rosin oil. Rosin spirit is water-white in color,
smelling of terpene. It is generally heavier than
turpentine. The sp. gr. may vary from 0.852 to
0.883 and the flash point from 96 degrees to 102
degrees F. in closed tester. It has no rotary
power, one sample showing only [a] v ' = + 0.2;
the refractive index of same sample being 1.4780.
It should not contain rosin oil. The bromide test
is 184 to 213.

Rosin spirit is said to contain pentine C H 8
(b. pt. 50 degrees), isobutylaldehyde, isobutyric, ca-
proic and other fatty acids, methyl alcohol (50 gr.
from 150 kilos.), a hydrocarbon C Hi 2 (b. pt. about
160 degrees C.), a homolog of benzene, ordinary
cymene and a new cymene (metapropyltoluene),
metaisobutyltoluene (186-188 degrees), parabutyl
toluene, dipentehe, a large portion of a heptine
C; Hi2 (103 to 104 degrees), probably methyl propyl
ene CH 3 . CH: C: CH. Ca H 3 . This liquid is char-
cterized by giving a succession of colors (yellow,
red, green, deep blue) when agitated with strong
sulphuric or hydrochloric acid. In presence of air
and water, it forms a gylcol C? Hw (OH) 2 , which
crystallizes with one molecule of water in long,
slender prisms, seen in old samples of resin spirit.

Rosin Oil.

This oil is produced by the destructive distilla-
tion of rosin and comprises the bulk of the distil-
late. The specific gravity of rosin oils ranges be-
tween 0.975 and 0.995. That ordinarily used is be-
tween 0.982 and 0.988. The iodine value averages
112 to 115. B. pt., 300 to 400 degrees C.

As much as 4 to 10 per cent unaltered rosin often
distills over, and this gives an acid reaction to the
oil of from .05 per cent to 5 per cent.

Rosin oils are soluble in ethyl alcohol and also
in a mixture of phenol and glycerine; also in
phenol alone, but. not in glycerol. Alcohol with
phenol dissolves it, as do carbon bisulphide and
turpentine. A mixture of equal parts of phenol,
alcohol and rosin oils forms a good mixture.

The action of nitric acid on rosin oil varies;
some grades it attacks readily, while other
grades are not affected unless heated.

Rosin oil is not truly saponified by alkalies, but
unites with them to form greasy bodies. A mixture
with lime solidifies soon; one with caustic soda in
a few days, and with caustic potash in a longer
period. A formula of 13Cio Hie Ca (OH)2 is ascribed
to the commercial "Rosin grease."

Renard considers that about 80 per cent of rosin
oil consists of diterebentyl Cao Hso (b. pt. 343-346
degrees C.), 10 per cent of diterebentylene 20 Has
and 10 per cent of didecene C*) Hsa (b. pt. 332 de-
grees C.).

Some consider that rosin consists of a mixture
of abietic acid CM HM 65 (m. pt. 165 degrees C) and
small quantities of phenols, with a mixture of hy-
drocarbons (Cio Hio) n (b. pt. above 360 degrees
C.). Rosin oil is used as an adulterant for olive
and boiled linseed oils and other oils and a*, w
lubricant on iron bearings.

Wood Oil.

This term is applied to the first oil distilled from
tar and also the oil dissolved in the pyroligneous
acid.

Refined wood oil is the oil distilled from this
crude oil by means of steam. There are a
great many different substances found in the crude

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

129

oil, a list of which has been already given. The
wood oil from hardwood has been investigated by
G. S. Fraps and described in the American Chemi-
cal Journal, Vol. 25, No. 1. The light oil from fir
wood, which would resemble pine wood oil, has
been investigated by the chemists at the University
of Washington at Seattle. This can be found in
Journal American Chem. Society, Vol. 25, Part II.,
p. 7G4.

The wood oil will vary according to the method
of production, but it can be expected to contain
tbe light rosin oils and light tar oils. The inter-
esting feature to the distiller is that an oil can be
produced that is very light and equal in quantity
to about two-thirds the amount of the turpentine
produced. This oil is generally yellow and turns
darker upon exposure to the air, due probably to
the presence of a tar product. The oil when first
distilled from the tar, contains a large amount of
creosol and some carbolic acid, both of which can
be removed with soda. This oil, when oxidized suf-
ficiently to destroy the coloring matter and then
redistilled, can be made almost water white in color.

The refined oil has a distinctive odor, is a pow-
erful solvent, a quick dryer, and can be used for
outside painting. It is often used as a creosote
paint when mixed with suitable pigments. In this
case it is better not to remove the creosols and
phenols.'

It has a different composition from oil of tar
produced by destructive distillation of the tar, but
it contains some oil of tar, that is formed by the
decomposition of the tar in the retort while the
v/ood is distilling.

Tar.

Tar obtained by destructive distillation of pine
wood in closed vessels seems to be somewhat dif-
ferent from the pine tar coming from a tar kiln.
There are several reasons to be ascribed for this;
one is that the turpentine is removed, another that
the tar itself is decomposed into lighter oils and
depositing coke, and another reason is that the tan-
nin in the wood acts on the iron of the retorts and
stills and causes a dark color.

In making kiln tar only extremely fat wood is
used, while in retorts a poorer quality is often
used. Lean woods give dark tars, sawdust tar
being nearly black.

The following comparison between fir tar from
a retort and Stockholm and pine tar is given be-
low:

Fir Tar. Stockholm. Pine Tar.

Color. Black almost. Brownish black. Brown.

Smoky but

Odor. Characteristic. Smoky. Resinous.

Consistency. Syrupy. Syrupy. Syrupy.

Specific gravity 1.10 1.09 1.11

Per cent. Per cent. Per cent.

Light oil 3 3 3

Creosote oil 34 30 40

Pyroligneous acid.. 45 2

Pitch 59 62 53

Hardness

of Pitch. Brittle. Less Brittle. Soft.

Color of Pitch. Black. Black. Brown.

Light oil sp. gr. 0.945.
Color. Amber.

Norwegian tar, according to Knut Strom, has
the following characteristics: Strongly acid, sol-
uble in alcohol, acetic acid, ether chloroform, and
benzene. Sp. gr. at 15 degrees C., 1.068. Compo-
sition 4.78 per cent volatile acids (as acetic acids),
11 per cent phenols and 61 per cent hydrocarbons.
Volatile acids (85 to 90 per cent) formic and ace-
'tic; proprionic acid, normal butyric acid, normal
valeric acid, (the normal valeric acid discovered
by Renard in pine resin M. pt. 175.5 degrees C.),
methyl propylacetic acid, normal caproic acid,
oenanthylic acid and normal caprylic acid. No un-
saturated acids discovered. Of the phenols, were
found phenol, guaiacol, cresol, creosol, ethylguaia-
col and two phenols Cu Hw Oa Ci 2 Hu Oa, respec-
tively. Of the hydrocarbons about 14 per cent
solid (containing retene Cis His), and 86 per cent
liquids. J. So. Chem. Ind., 1900.

The specifications required for good pine tar

are given below:

Deg. C. Per ct.

Distilling under 150 9.70

Distilling between 150 350 42.61

Distilling between 350-363 26.62

Coke . 21.07

130

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

Some of the products of distillation of different
tars will be found in Chapter XII.

Pitch.

There are several kinds of pitch coming from
different sources, such as coal tar, wood tar and
rosin pitch.

Stockholm pitch is made from pine wood tar
either by boiling it down or by destructively dis-
tilling it. This pitch is brilliant black, having a
conchoidal fracture, but brittle, crumbling between
the fingers. Its specific gravity is 1.105 and melt-
ing point 82 degrees C. It is slightly adhesive,
and becomes sticky on warming; at 40 degrees C.
it twists easily. When heated, 88 to 88% per cent
volatilizes, leaving a soft, friable coke containing
.7 to .84 per cent ash. The odor when boiling down
is very distinctive.

Benzol dissolves it, and also pyridine bases. Pe-
troleum spirit dissolves only 91 to 92 per cent.
Sulphur present, only .01 per cent. The solution
in petroleum shows no bloom or fluorescence, the
spectroscope cuts out only the violet spectrum, no
bands visible, nor is there any indication of chry-
sene said to exist in this particular tar or pitch.

This pitch dissolves almost completely in alco-
holic potash. This neutralized and boiled yields
volatile fatty acids. (Thorpe's Diet, of Applied
Chem.).

Pyroligneous Acid.

This acid comprises chiefly acetic acid, wood
alcohol, acetone and dissolved oils. Other prod-
ucts are found and are contained in the list pre-
viously given. The amount of acetic acid from
pine wood is equal to about 2.5 to 5.5 per cent of
the weight of the pyroligneous acid.

Acetic Acid C 2 H 4 Os = C H 3 C O 2 H.

This acid is produced chiefly from table vine-
gar made from alcohol and from wood vinegar or
pyroligneous acid. It is also a product of the
decomposition of cellulose by alkalies and acids.

The strongest acetic acid is known as "glacial
acetic" acid, from its crystallizing in icy leaflets
at about 40 degrees F. Above CO- degrees the

crystals fuse to a thin, colorless liquid of an ex-
ceedingly pungent and well-known odor.

The gravity of pure acetic acid is given as 1.055
to LOGO at 59 degrees F. The sp. gr. of a solution
of acetic acid in water is no indication of the
amount of acid. Common acetic acid of commerce
is a slightly colored liquid of about 1.04 sp. gr.,
and containing appromixately 30 per cent anhyd-
rous acid.

The boiling point of pure acetic is 118 degrees
C. It gives off a vapor which burns with a flame
like alcohol.

The action of heat is interesting, as it is some-
times affected in a hot retort. When its vapor
is passed through a red-hot tube, it yields several
products, among which marsh gas and acetone are
conspicuous. This action is much more marked
in the presence of glowing carbon. Acetic acid is
very corroding. It strongly attacks iron; wrought
iron is eaten out very quickly and cast iron be-
comes so soft that it can be whittled with a knife.
It has been found that real hot vapors affect
wrought iron less than colder ones, hence we find
that the hottest parts of a retort are made of
wrought iron, while the connecting pipes and cooler
parts of the retort, such as the head, are made
of cast iron. Acetic acid attacks copper slowly
to form acetate or verdigris.

Acetic acid is the strongest organic acid and is
not easily oxidized. With alkalies and metallic
bases it forms acetates which will not be de-
scribed, except calcium acetate.

Commercial acetic acid is prepared from gray
or brown acetate of lime by distilling with con-
centrated hydrochloric acid in copper stills, care
being taken to have an excess of lime salt in the
still. The acid formed is colored and contains
about 50 per cent anhydrous acid. With dilute
acid in the still, the acid is purer and contains
only 30 per cent anhydrous acid. Often the acid
is distilled in Marx vessels and filtered in towers
through freshly burned charcoal.

Wood Alcohol C H, O = C H 3 O H.

This substance in a pure state is a colorless,
mobile liquid, known as Columbian and Colonial

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

131

spirits. It boils at 149 degrees Fah. It is very in-
flammable, burning with a pale flame. The pure
alcohol is difficult to distinguish from grain or
ethyl alcohol, as the odor and color are alike.
Methyl and ethyl alcohol can be distinguished from
each other by distilling them with dilute sulphuric
acid and potassium dichromate, when the former
yields formic acid and the latter acetic acid. The
formic acid produced may be distinguished from
the acetic acid by its property of reducing silver
ammonio-nitrate to the metallic state when
warmed with it.

Methyl alcohol forms a crystalline compound
with calcium chloride (C'a C1 2 ) the formula being
Ca Cb (C Hi O>4. This compound is stable at
100 degrees C., so by heating to 100 degrees C.
the acetone and methyl acetate distill over from
crude wood spirit, leaving this compound. By
adding an equal weight of hot water this compound
is decomposed, and by continuing the distillation,
pure methyl alcohol distills over, accompanied by
some water, which can be removed by contact with
quicklime and distillation. It can also be obtained
pure from wood spirit by heating with anhydrous
oxalic acid in a flask connected with an inverted
condenser, until the methyl alcohol is converted
into methyl oxalate (C O. O C H 3 ) 2) which sep-
arates in crystals on cooling. The crystals are col-
lected, washed with water and distilled with potash.

Commercial methyl alcohol is often slightly yel-
lowish in color and has a disagreeable odor. It
is largely used as a solvent in varnish making, the
acetone contained therein being an advantage.
The turbidity noticed when crude wood spirit is
mixed with water is due to the separation of hy-
drocarbons, which were contained in the alcohol.

Wood alcohol is used for the preparation of
methylated spirit or, as it is called, "denatured" al-
cohol, which is a mixture of grain alcohol with a
small percentage of wood alcohol or other denatur-
izing agent.

Its production in the United States will prob-
ably be somewhat curtailed on account of the lack
of demand, due to the use of "denatured" alcohol
in its stead.

Acetone.

Acetone is found in wood spirit. It boils at
56.3 degrees C., and hence cannot well be removed
from the alcohol by distillation over lime. To re-
move it, the alcohol is fixed by the calcium chlor-
ide, as described under wood alcohol, and the
mixture distilled under 100 degrees C. until the
acetone is driven out.

Regnault and Villejean dissolve in the wood
spirit, previously purified as much as possible, 10
per cent of its weight of iodine, add concentrated
solution of potassium hydroxide in small portions
until decoloration is complete, and distill the mix-
ture at a very moderate heat. The iodine and
caustic unite with the acetone to form iodoform.
Sometimes the alcohol is treated with chlorine and
chlor-acetones are formed showing high boiling
points and from which the alcohol is separated
by distillation.

On a commercial scale, acetone is .made by the
dry distillation of gray acetate of lime at 290 de-
grees C. in retorts which are connected with a
cooling apparatus. In Chute's process the pulveru-
lent material is continuously conveyed in a thin
film or layer over a heated surface maintained at
the proper temperature, and the acetone is re-
moved by a current of oxygen-free gas moving in
an opposite direction, under a partial vacuum, the
gas being reheated and reused.

A commercial method for the production of ace-
tone devised by Dr. E. R. Squib consists of pass-
ing acetic acid vapor through a rotating iron cylin-
der, heated to about 500-600 degrees C., and con-
taining pumice stone with precipitated barium
carbonate. On leaving the still the vapors pass
through a fractional condensation apparatus, to
remove water and acetic acid; the dilute acetone
condenses in a second condenser. The barium car-
bonate acts merely as a contact body, since the
temperature is always above that at which barium
acetate decomposes.

Acetone produced from acetate of lime by distil-
lation is impure and needs refining. Sodium bisul-
phite is added to form a double salt with the
acetone, which is readily purified by crystallization

132

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

from aqueous solution. By heating this salt with
sodium carbonate solution, acetone is set free and
may be distilled off in a pure state. The water is
removed by fused calcium chloride.

This action of sodium bisulphite can be utilized
to remove acetone or other ketones from wood
oils. When acetone loses the elements of water
by the action of dehydrating agents such as
Hr S O 4 HC1 and Ca O, condensation products are
formed, such as mesityl oxide, a liquid smelling of
peppermint and boiling at 130 degrees C. (2(CH 3 )2
CO H 2 O), phorone and mesitylene, all of which
are found in the products of distillation of pine
wood.

The sp. gr. of acetone is 0.80. It is inflammable,
burning with a luminous flame. It mixes with
water, alcohol and ether. When oxidized it yields
acetic acid and carbon dioxide.

Acetone can be separated from a comparatively
strong aqueous solution by adding concentrated
calcium chloride. The acetone will rise to the
top.

Calcium Acetate.

This substance is found in trade as the gray and
brown acetate of lime. There is also, of course, a
chemically pure salt.

The difference lies in the amount of tarry mat-
ter contained therein. Generally the yield of
brown acetate of lime is one-third greater than
that of the gray, but, of course, it means more im-
purities rather than more acetic acid.

To make acetate all the waste heat is utilized
as far as possible, some plants even putting their
acetate pans on top of the retorts.

It is cheaper to make brown acetate of lime, as
it takes less fuel. This form of acetate is made
by directly neutralizing the pyroligneous acid with
lime and then distilling off the alcohol. The resi-
dual liquor is then evaporated to dryness and par-
tially charred to destroy tarry matters. The gray
acetate is made by distilling the pyroligneous acid
to remove both the acetic acid and alcohol. The
acetic acid vapor is passed through lime before

it reaches the condenser, thus fixing it, while the
alcohol vapor passes on and is condensed.

Brown acetate is made at some plants from the
pyroligneous acid obtained from pine wood by sim-
ply evaporating without the recovery of the alco-
hol. This product does not give as much satis-
faction as the hardwood variety.

As stated under destructive distillation methods,
acetate is made by neutralizing the settled pyrolig-
neous acid exactly with lime or limestone and
filter-pressing to remove tarry products and im-
purities in the lime, etc. The fluid is then acidu-
lated with crude hydrochloric acid and allowed to
rest, whereby a deposit is formed. The clear
liquor is drawn off and evaporated in copper pans
heated by steam and provided with a set of stir-
rtrs to prevent the acetate from burning to the
bottom. The tarry matter rising to the surface is
removed through a sliding door. When the sp. gr.
(measured hot) reaches 1.116, the separation of
acetate begins, and gradually the mass forms a
thick paste which is removed and spread on flat
iron pans to be dried. During this last operation,
the material should be constantly stirred with iron
shovels. Some finish the drying in rooms heated
with waste furnace or retort gas.

Sometimes gray acetate is made by distilling the
alcohol and then after changing the receiver the
acetic acid is distilled over and afterwards neu-
tralized with lime and evaporated in the usual
manner.

In the North, the acetic acid and alcohol are re-
moved by distillation, the tar remaining in the
still. The distillate goes to another still, where
lime is added and the alcohol distilled off. The
acetate in the still is removed and evaporated in
the usual manner, forming gray acetate.

Charcoal.

The residue in the retort left after distilling
wood is charcoal, and it is very important that
it contains but little tar, as this will cause it to
smoke.

The amount of carbon in charcoal produced at
various temperatures is shown as follows:

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

133

Temperature of carbonization.

Cent. Fahr.

150 302

200 392

250 482

300 592

350 662

432 810

1023 1873

Carbon per cent
47.51
51.82
65.59
73.24
76.64
81.64
81.97

It will be noticed that there is little to be gained
by heating above 810 degrees Fan.

Charcoal exposed to the air absorbs moisture in
variable quantity, according to the temperature at
which it was burned. Thus, at 150 degrees it ab-
sorbs 21 per cent of its weight; at 250 degrees, 7
per cent; at 350 degrees, 6 per cent; at 450 de-
grees, 4 per cent, and at about 1500 degrees C.,
about 2 per cent.

The kindling temperature in the open air is
higher where the heat has been greater. Thus
coals burned at 260 degrees to 280 degrees take
fire at 340 degrees to 360 dgrees C.; those burned
at 290 degrees to 350 degrees take fire at 360 de-
grees to 370 degrees; those at 400 degrees kindle
at 400 degrees, and those at 1000 to 1500 degrees,
at 600 degrees to 800 degrees, and these latter
burn with difficulty.

Charcoal has great powers of absorption. It will
absorb coloring matter from liquids and also ab-
sorb large quantities of gases, those gases that are
most soluble in water being the most absorbed.
This property is much more marked when recently
charred and the air excluded.

In a box or case containing one cubic foot of
charcoal may be stored a little over nine cubic
feet of oxygen, representing a mechanical pressure
of 126 pounds to the square inch. From the store
thus preserved, the oxygen can be drawn by a
small hand pump.

The composition of charcoal made at the same
temperature varies with the different woods. One
species of wood burned at various temperatures
gave the following:

Temperature

of charring.

Carbon.

Hydrogen.

Oxygen.

Ash.

270 Deg. C.

71.0

4.60

23.00

1.40

363

80.1

3.71

14.55

1.64

476

85.8

3.13

9.47

1.60

519

86.2

3.11

9.11

1.58

The specific heat of charcoal at different temper-
atures is given below:

0-23 Deg. C.
.1653

0-90 Deg.
.1935

0-223 Deg.
.2385

CHAPTER XL

YIELDS AND DISPOSALS OF PRODUCTS.

The question arises, what is the yield of differ- From dry distillation of the wood:

ent products per cord of wood when distilled?' It G rey acetate of lime 46.2 ibs.

is quite apparent that the amount of different prod- Light oil 18.4 gals. 2.34

ucts will vary greatly, according to the different Charcoal 1050 ibs. 17.50

conditions. The unit is generally .the cord, al- Gas 3750 cu. ft. (?) 2.00

Wood tar 1217 Ibs. 20.23

though the amounts and percentages are some-
times given by weight. From distillation of rosin:

A cord of wood means 128 cu. ft.., feut it never Rosin spirit 2.5 gals. 0.3

amounts to that much; knots, crooked sticks, short Rosin oil 10.9 gals. 1.5

ends, etc., 'all cause the actual quantity to be less. Blue o11 7 - 25 sals. i.o

Green oil 5.6 gals. 0.8

The amounts should be determined by weights,

Pitch 12 Ibs. 0.2

and even then differences occur on account of the

varying content of water. From distillation of wood tar:

The actual per cent of wood as given by Marcus

Creosote oil (lo per cent) ... 306 Ibs. 5.1

Bull, is 56 per cent solid wood and 44 per cent wood pitch 516 ibs. 8.6

interstitial spaces.

From creosote oil:
The official determination in Prussia, according

to B. E. Fernow, is: Creosote 45.9 Ibs. 0.76

Specific gravity of the woo'd, 1.075.

Firewood cords. Billet cords.

A test on 600 Ibs. of dry light wood gave the
Timber cords, (over 6" diam.) (over 3" diam.)

Cu. ft 80 75 60 following:

Pounds.

Brushwoods Spirits of turpentine 21%

(less than 3" diam.) Roots. Pyroligneous acid 95

Cu. ft 23.70 47.36 Heavy oils and tar 150

Charcoal 127

The amount of turpentine in the pine may be Water and gas 206%

stated to vary from 0.27 to 3.50 per cent of the Total

weight of the wood.

A complete test of light wood estimated at 6,000 This is su PP s ed to equal a yield by the cord of

Ibs. to the cord was made at the Massachusetts 24 gallons s P irits of turpentine, 88 gallons of

Institute of Technology, with the following results. Pyroligneous acid, 120 gallons tarry and heavier

The turpentine was taken off with steam at 40 oily P roducts and 56 bushels of charcoal.

Ibs. pressure, and the residue destructively dis- One of the earlier plants gives the following from

tilled: a cord: Spirits of turpentine 5 to 18 gallons, of

From steam distillation: heavier oils and tarry products known as dead oil

or creosote from 60 to 100 gallons, and of stronger

acid (of a specific gravity 1.02) 60 gallons, or of
Product. Amount. per cent.

Turpentine 24.9 gals. 3.00 W6aker aCid 12 gall nS '

Yellow oil 4.4 gals. 0.56 ^ n ana ly s is given by Prof. Cox is as follows:

Rosin 318 Ibs. 5.30 First quality, turpentine, 16 gallons; second qual-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

135

ity, turpentine, 10 gallons; alcohol, 6 gallons; ace-
tate of lime, ICO Ibs.; tar, 1 barrel.

Another from a card weighing 5,000 pounds, 8%
tc 9 gallons turpentine, a barrel to a barrel and a
quarter of tar, about a gallon and a half of al-
cohol and atout 170 gallons pyroligneous acid.

Another more detaileu, the results of investiga-
tions made by Mr. J. D. Lacey, of New Orleans:

Turpentine 22 gals.

Pine Tar 75 gals.

Wood alcohol 2 gals.

Lime acetate 40 Ibs.

Charcoal 48 bu.

Another:

Russian turpentine 16 gals.

Rosin oil 42 gals., kidney.

Rosin oil 8 gals., heavy.

Creosote 10 gals.

Wood alcohol 4 gals.

Acetate of lime 100 Ibs.

Charcoal 500 Ibs.

No one has experimented with wood of varying
fatness, using large quantities.

The author made a test on some long leaf yellow
pine cut into short lengths. These short lengths,
after cording carefully, measured 2.36 cords and
weighed 8.G14 Ibs., or about 3,647 Ibs. per cord.

The yield per cord, air dry, was as follows:

Weight, Ibs. %

Clear white turpentine.. 18.64 gals. 134.20 3.679

Wood oil 11.09 gals. 86.50 2.371

Tar 96. gals. 846.72 23.216

Acid 95.9 gals. 830.49 22.771

Coke 14.74 .404

Charcoal 796.00 21.826

Yellow oil and pitch 6.78 gals. 57.02 1.563

Gas and loss... 881.33 24.16G

Total 3647.00 99.996

The turpentine, after distilling, was a clear
white oil, testing as follows: Sp. gr. at 20 degrees
C., 0.8654-B. Pt. 156.5 degrees C. Index of refrac-
tion, 1.47210, sp. rot. power plus 17.91 at 20 de-
grees C., flash point 32 degrees C. (closed tester).

The turpentine was taken off by means of super-
heated steam under a pressure of only a few
ounces, then redistilled, yielding the above

quantity of oil. The residue was then destructive-
ly distilled and the wood oil steamed from the
tar. The wood oil contained no turpentine, but
did contain large quantities of rosin oil and creo-
sote oil.

In Minnesota, with Norway pines, the yields are
said to be:

Turpentine 16 gals.

Tar 30 gals.

Charcoal 30 bu.

On the Pacific coast, with fir, the yields are
about the same as in Minnesota on the same class
of wood.

With sawdust the yield varies with the amount
of rosin in the wood, from y 2 gallon to 5 gallons
per ton, air dry. With fat slabs the yield would
be about 24 gallons, or less, according to rich-
ness.

The yield depends entirely upon the resin, as
nearly all processes will extract the oils if given
t!me and heat enough. In destructive distillation
processes it can be readily understood that too
rapid heating causes more gas at the expense of
the other products.

In the hardwood industry one plant using 70
per cent, maple averaged per cord as follows dur-
ing the year 1906, from wood four foot long:

Wood alcohol 11.32 gals., 82%

Acetate of lime 172.56 Ibs.

Charcoal 54.18 bu.

In the United States, by weight, for hardwood,
the following are given as the average results
in per cent:

Wood alcohol 1.434

Acetate of lime 6.250 82%

Charcoal -31.2

In Germany the results from a cord of pine are
as; follows:

Turpentine 12.25 gals.

Brown acetate 88.82 Ibs.

Tar ' 40.4 gals.

Wood alcohol 8.!% 4.1 gals.

Charcoal 808.0 Ibs.

The following table of yields is given by the
Bureau of Chemistry and gives an idea of the
variableness of the yields from different woods.

136

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

AMOUNT OF PRODUCTS YIELDED PER
Alcohol
(crude)

CORD OF WOOD.

containing Acetate

Turpen-

Classes of woods.

Charcoal.

acetone.

of lime.

Tar.

Wood oils.

tine.

Gas.

Bushels.

Gallons,

Pounds.

Gallons.

40 to 50

8 to 12

150 to 200

8 to 20

Resinous woo'ds

25 to 40

2 to 4

50 to 300

30 to 60

o!2 to 25

b2 to 10

Sawdust (hardwood) .

. . 25 to 35

2 to 4

45 to 75

a Lightwood.

b Sawdust.

With pine, the yield in turpentine by steam dis-
tillation is, with ordinary pine 2 to 5 gallons per
cord, while good light wood yields from 10 to 20
gallons and averages about 15 gallons per cord,
and very rich light wood from 20 to 30 gallons per
cord.

Unfortunately, the greater amount of the available
pine is of the low yielding variety and the supply
of good light wood at most plants is soon ex-
hausted, thus causing failure.

RESULTS FROM DIFFERENT METHODS
CHARCOAL MAKING.

* <

',* ft

-0
I* <D <D

P 1^
oj 31 -2 )
h 'O O o

28 > ^
* 2 c
u > M a

In weight
per cent.

Bushels of <
coal per cor

Weight in 11
bushel of cl

periments: birch

35.9

rt
O
U

Odelstjerna's ex
dried at 230 F

Mathieu's retorts, fuel excluded,
(air dried, average good yel-
low pine, weighing about 28 Ibs.
per cu. ft.) 77 28.3 63.4 15.7

Mathieu's retorts, fuel included,
(air dried, average good yel-
low pine, weighing about 28 Ibs.
per cu. ft.) 65.8 24.2 54.2 15.7

Swedish ovens, average results,

(good 'dry fir and pine mixed). .81.0 27.7 66.7 13.3

Swedish ovens, average results,
(poor wood mixed fir and pine).. 70.0 25.8 62 13.3

Swedish meilers, exceptional (fir
and white pine wood mixed,
average 25 Ibs. per cu. ft.) 72.2 24.7 59.5 13.3

Swedish meilers, average results. 52. 5 18.3 43.9 13.3

American kilns, average results,
(average good yellow pine
weighing about 25 Ibs. per cu.
ft.) 54.7 22.0 45 17.5

American meilers, average re-
sults, (average good yellow
pine, weighing about 25 Ibs.
per cu. ft.) 42.9 17.1 35 17.5

DISPOSAL OF THE PRODUCTS.

With the demand for turpentine increasing at a
rapid rate, it would seem an easy proposition to
dispose of some of the products of distillation.
However, the prejudice against wood turpentine and
retort tar is still very great.

Turpentine. Turpentine ought to be sold as
such upon its merits. It is necessary to make a
refined article of stable quality in order to com-
mand a ready sale, even at a less price than the
market price of orchard turpentine.

Any surplus might be disposed of by converting
into turpentine derivatives, such as terpine
hydrate, terpineol (used for making lilac perfume),
camphor, artificial camphor and similar com-
pounds.

Yellow Oil. This compound, if it proves to be
terpineol, may be changed into numerous bodies.
In the present state of knowledge regarding this
product it may be used in combination with caus-
tic as a disinfectant, for stack paint or for mix-
ing with the residue for kindling.

Wood Oil. The refined wood oil can be mixed
with suitable colors to form shingle stains. The
crude wood oil can be used for dark colored shin-
gie stains and for creosote paints.

The pyroligneous acid is sometimes used as a
sheep dip, disinfectant, spray on trees, etc. It
can be converted into acetate of lime and black
liquor (iron acetate), which latter is used as a
mordant for dyeing, and can also be used for a
black stain on wood.

Tar oil, the name applied to the crude tar and
oil coming from the retort, is used in various
ways, as for soap, etc., also for creosoting lumber.

THE UTILIZATION OP WOOD WASTE BY DISTILLATION.

137

Tar. This is generally sold as such, but may
be regularly distilled to produce oil of tar, creo-
sote oil and pitch. Black tar and pitch might be
used in road-making and for making products
where coal tar is now used.

Rosin and Resin. These are best sold as such,
or mixed with the tar. A separate plant might
be added to destructively distill to obtain rosin
spirit, rosin oil and pitch. The rosin itself might
be sold to ship chandlers, sealing wax manufact-
urers, etc., or when the residue from the steam
process is used for making gas, this can be added
to the wood to make rosin gas.

Charcoal. The two chief methods of disposing
of this are domestic use and for blast
furnace consumption. In the latter case
the advisability of encouraging the use
of brands or half-charred pieces is to be com-
mended. In this way destructive processes do not
take so long, the tar is better and the weight of
the brands is greater than that of the charcoal.

The coke on the bottom of the retort contains
considerable ash. Probably the best use of this
is for fuel, although at many plants it is thought
that this material won't burn. It has been sug-
gested to grind up this material and use it for
similar purposes as gas carbon.

The production of this coke should be avoided
as far as possible by careful operation.

Residue from the Steam Process. The proper
disposal of this residue at satisfactory prices will
help solve the problem of the utilization of waste
pine wood. The following are suggestions: Side-
walks in small towns (used as such in Germany) ;
fuel, wall-plaster, kindling (by mixing with rosin
or yellow oil) ; destructive distillation in special
retorts for tar products and gas-making; oxalic
acid, ethyl alcohol and cellulose products.

Many attempts are being made to find a process
that will enable the residue to be converted into
paper. So far everything designed is the reverse
of what it should be. The paper industry is more
important than the pine wood distillation industry
can ever hope to be. Instead of devising a process
for making the residue from a turpentine process

into paper, a process for making paper which
will incidentally extract the turpentine is the
process that is required.

In making paper the resin, which is of impor-
tance to the distiller, is a detriment to the paper-
maker. In making turpentine from pine wood only
fat wood is used, except in a few instances. The
bulk of the waste wood is not fat, consequently
only in those cases where the waste is cheap,
such as sawdust, can any distillation process ex-
tract enough turpentine to pay for gathering the
wood. Unless then, the extraction of the turpen-
tine pays for itself, there is nothing to be gained
in this manner, for the paper manufacturer can ob-
tain his stock as cheaply without the turpentine
being extracted.

To utilize waste wood by converting it into pa-
per, the proper place to extract the turpentine
would be at the digester of the paper mill, instead
of at the digester or retort of a turpentine ap-
paratus.

The author visited a paper mill using yellow
pine and found that all that was necessary to re-
cover the turpentine was the placing of a con-
denser and a valved connecting pipe at the top of
the digester. Using the soda process of paper-
making, the reaction in the digester is carried out
at a pressure of 90 to 110 Ibs., the heating being
done by means of steam. This action thoroughly
extracts the turpentine, more so than many of
the processes herein described, as the heat is con-
tiued longer. The action of the caustic is not nec-
essarily detrimental, as it combines with any tarry
matters.

With a digester fitted with a condenser, all that
is necessary is to open the valve leading to the
condenser, and the oil, mingled with water, will
flow out from the end of the condenser. The oil
is found to be slightly yellow, the same as ordinary
crude oil produced from steam pressure processes.
By a simple redistillation this can be made white.

If all classes of waste pine wood could be made
into a quality of paper that it would pay to make,
then the above method of extracting the turpen-
tine while making paper solves the problem of

138

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

the utilization of the waste wood from pine and
fir wood. The question is up to the paper manu-
facturer, and not to the wood distiller.

An exception may be made to the above method
in the case of resinous wood, but only a small
quantity of the waste is fat. However, fat wood
could pass through the above process and be as
good as it would be if it passed through any of
the regular distilling processes, except those that
extract the resin by other means than caustic.
With fat wood more caustic would be needed in
the digester in order to remove the excess of

resin, and this alkali could be recovered in the
usual way, or with very fat wood, might be neu-
tralized and the resin recovered. The turpentine
would come off as usual. The quality of the paper
would be the same, whether the oil was recovered
in a regular distilling apparatus or in the diges-
ter of the paper mill. It can be readily under-
stood that the pressure in the digester can be low
while the turpentine is being taken off, if desired.
Attempts are being made in New York State to
recover turpentine from spruce, and the above
method, if tried, will be found the most suitable.

CHAPTER XII.

CHEMICAL TESTS AND COMBINATIONS.

In this chapter will be recorded some of the tests
and analyses of the different products as made by
various investigators. Some have already been
given, and they will not be repeated. In addition
will be given methods of combining the different
products. in order to produce some of the various
derivatives.

Turpentine. The results of the test applied to
the turpentine produced at the Massachusetts In-
stitute of Technology by distilling fat wood with
steam are given "below:

Specific gravity 0.865 0.867

Color some samples Water white

Spec. rot. power + 28.7

Aci'd value's 0077 to .0079%

Esters as bormyl acetate 7%

Distilling below 163 degrees C 80%

Distilling below 175 degrees C 90%

Residue upon evaporation 0.71 to 1.02%

(For others see Chapter X.)

Tar. Several statements have already been
made relative to the tests that have been made on
tar. The following are distillation tests on various
tars:

PARTS.

Ga's

Light Heavy and

Acid Oil Oil Pitch loss
Meiler tar from So. Austrian

Black fir sp. gr. 1.075 10 10 15 50 5

Specific gravity (.966) (1.014)

Meiler tar from Bohemian pine

sp. gr. 1.116 10 5 15 65 5

Specific gravity (.977) (1.021)

Retort tar from Salzburg sp.

gr. 1.18 10 10 15 55 10

Specific gravity (1.012) (1.022)

Tar from distillation process by

superheated steam 5 20 25 30 5

Specific gravity (.920) (.978)

Hardwoods give on an average a tar which by
distillation yields according to Vincent:

Watery distillate (wood spirit, acetic acid) ... .10 to 20%
Oleaginous light distillate sp. gr. 0.966 to 0.977.. 10 to 15%
Oleaginous heavy distillate sp. gr. 1.014 to 1.021.10 to 15%
Pitch 50 to 65%

ANALYSIS OF CHARCOAL.

Heat Hydro- Oxygen

Product. C. Carbo"h, gen. & Loss Ash

Dry wood 150 45.71 6.12 46.29 .08

Charred wood 260 67.85 -5.04 26.49 .56

Red charcoal 280 72.64 4.70 22.10 .57

Brown charcoal 320 73.57 4.83 21.09 .52

Dull black 340 75.20 4.41 19.96 .48

Lustre black 432 81.64 1.96 15.25 1.16

Extreme white heat. 1500 96.52 0.62 0.94 1.95

GAS.
Analyses of wood gas made by Pettenkofer show:

Heavy

Carbonic Carbonic Hydro-

Add Oxide Methane Hydrogen carbons
Per cent.. 18 to 25 40 to 50 8 to 12 14 to 17 6 to 7

Some gas purified gave:

Heavy

Carbonic . Hydro-

Oxide Hydrogen Marsh gas carbons
Percent 25 to 40 29 to 49 24 to 35 7 to 9

An analysis of the gas from distilling fir made
at the University of Washington, Seattle, Wash.,
gave the following results:

Car- Light Nit-
Carbon bon Hydro- hydro- ro-
Dioxide Monoxide gen Methane carbon gen
Per cent 12.3 28.8 80.6 7.3 6.3 14.7

From analyses of gas generator gases:

Carbonic acid 10.00 10.70 15.20

Carbonic oxide 18.50 17.90 15.40

Methane 0.70 3.10 7.20

Hydrogen 17.40 17.60 12.60

Nitrogen 53.40 50.70 49.60

The gas from yellow pine contains all the above
ingredients and also some that are characteristic
of rosin gas. A gas made from Virginia pine by

140

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

Pettenkofer's process, which consists in charring
the wood and then pushing the charcoal formed to
the back of the retort and letting the water from
fresh wood pass through it while hot. analyzed as
follows: Hydrogen, 44 per cent; marsh gas, 5.4
per cent; carbon monoxide, 33.7 per cent; carbon
dioxide, 10.5 per cent; nitrogen, 6 per cent; oxygen,
0.25 per cent. A ton of wood (2,240 Ibs.) is said
to produce 36,500 cu. ft. of such gas.

Ordinary hardwood gas has tested 26 per cent
C O 2 40 per cent C O and 11 per cent marsh gas,
the remainder being hydrogen and hydrocarbons.
A purified gas showed as follows: 25 per cent
marsh gas, 30 per cent hydrogen, 30 per cent car-
bon monoxide, 8 per cent hydrocarbons and 7 per
cent carbon dioxide and air. It is difficult to puri-
fy over lime.

Tests of Pyroligneous Acid, Rosin, Oils, Etc.
The composition of these compounds has been stat-
ed under the description of the same, and it is not
necessary to repeat them at this place. It is well
to again call attention to the fact that those woods
which are hard containing relatively large amounts
of lignin and incrusting substances give larger
yields of acetic acid and methyl alcohol than those
woods containing but small amounts of this harder
material and consequently called soft wood.

Combinations or Derivatives.

Turpentine Derivatives.

Camphor do H O.

The most important derivative of turpentine is
camphor. To prepare two general methods are
pursued: one is to treat the turpentine direct with
suitable reagents, and the other is to first change
the pinene into pinene hydrochloride from which
camphor can be made.

The first method was tried unsuccessfully in this
country, but it is of interest nevertheless. The
process used was that of Thurlow, which consists
in heating the turpentine with anhydrous oxalic
acid at a temperature below 120 degrees C.

According to Collins, the process is carried out
on a small scale, as follows : In a steam-jacketed
reaction tank, oil of turpentine and anhydrous

oxalic acid are placed, the results of the reaction
being pinyl oxalate and pinyl formate. The liquid
mass formed is pumped into a set of stills for treat-
ment. Here it is distilled with live steam in the
presence of an alkali, the resultant formation oc-
curring as ordinary camphor and borneol camphor
dissolved in the oily products of the reaction.
These oils are fractionally distilled to extract the
camphor and borneol further. After the pleasant
smelling oils have passed over, the camphor and
borneol distill in the steam and are precipitated in
the condenser in a white mass somewhat resem-
bling boiled rice. The crude product is then forced
by compressed air through a filter press and thor-
oughly washed to free it from all traces of oil,
when it is dropped into an oxidizing tank, where
the borneol oxidizes into the ordinary camphor.

The mass is transferred to a rapidly revolving
centrifugal machine, where the oxidizing liquors
are thrown out and the camphor, being heavier, re-
mains behind comparatively pure, but stained from
the oxidizing compound, so that it resembles light
brown sugar. After removal from the separator
it is placed in a large steam jacketed sublimer. In
this vessel a slow heat frees it from any water
it may contain, and the temperature is then raised
to the boiling point of camphor and a rapid current
of air projected over the surface of the pan, blow-
ing the camphor into a condensing chamber, where
it settles in the form of snowflake-like crystals.

The yield of camphor by this process is from 25
to 30 per cent of the weight of the turpentine used.
In addition to camphor, there are a number of light
oils produced in the process, which are also found
in nature, namely, dipentene, oil of lemon, oil of
lime and a number of other natural terpenes and
essential oils. This process of synthetically pro-
ducing camphor takes about fifteen hours.

In most of the other processes pinene hydrochlo-
ride is formed by passing dry hydrochloric acid gas
into dry turpentine oil, both being well cooled. If
a rise in temperature is prevented during the reac-
tion the oil solidifies almost completely after sat-
uration with the gas to a camphorlike mass. Some
pass the gas into a mixture of turpentine and chlo-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

141

reform and distill off the chloroform and then the
hydrochloride.

This product is called artificial camphor Cio Hie.
H Cl. It melts at 125 degrees C. and boils at 208
degrees, suffering almost no decomposition.

The conversion of this product into camphor is
based on the fact that when the hydrochloric acid
Is removed by a feeble alkali, such as aniline, or
by means of sodium acetate and acetic acid, the
compound formed is not pinene, as would be ex-
pected, but camphene, a terpene closely allied to
camphor, which, by oxidation, can be converted into
camphor.

A process patented in this country uses lime to
remove the chlorine and then oxidizes the cam-
phene with nitric acid. It is doubtful if much cam-
phor would be produced when lime is used.

A general method for the production of cam-
phene is to heat pinene hydrobromide or hydro-
chloride with sodium acetate and glacial acetic
acid at 200 degrees C.

The oxidation of the camphene to camphor may
be performed in the following manner, using isobor-
neol as an intermediary:

Two hundred and fifty parts by weight of glacial
acetic acid and ten parts by weight of 50 per cent
sulphuric acid are mixed with 100 parts by weight
of camphene and the whole heated to 50 degrees
to 60 degrees C. for a few hours and the mixture
frequently agitated. Two layers are formed at first,
but after a short time a perfectly clear slightly col-
ored or colorless solution results. The reaction is
complete in two or three hours and the product is
diluted with water, the resultant isoborneol acetate
separating as an oil. This is washed a few times
to remove the free acid, and without further puri-
fication it is boiled for a short time with a solu-
tion of 50 parts by weight of potassium hydroxide
in 250 parts by weight of ethyl alcohol in a still
connected with a reversed condenser. The greater
part of the alcohol is then distilled off and the
residue poured into a large quantity of water; iso-
borneol is precipitated as a solid mass, which can
be separated pure by filtering and recrystallizing
from petroleum ether. The isoborneol is then oxi-

dized with just enough nitric acid, or with a solu-
tion of chromic anhydride in glacial acetic acid,
the resulting product being camphor.

Instead of using isoborneol itself, a German pro-
cess starts with isoborneol acetate or benzoate.
The oxidation may be performed, for instance, by
means of chromic acid, nitric add, permanganate,
manganese and sulphuric acid, Caro's acid, etc.,
working either in solution or in suspension. The
following formulas are given:

Ex. 1. One hundred and twenty-seven parts by
weight of isoborneol acetate are dissolved in 2,000
parts by weight of glacial acetic acid or other suit-
able acid, which is not affected by the oxidizing
agent, and then oxidized with 78 parts by weight
of chromic acid. The reaction being completed,
the excess of solvent is distilled off, the residue
washed out with water and purified in the usual
manner.

Ex. 2. One hundred and twentyseven parts by
weight of isobornyl acetate are well mixed with
78 parts by weight of chromic acid in 2,000 parts
by weight of water, at about 90 degrees C., until
no more free chromic acid is present. After cool-
ing the raw camphor crystallizes out and is then
purified in the usual way.

Ex. 3. One hundred and seventy parts by weight
of isobornyl benzoate are well mixed with 78 parts
by weight of chromic acid in. 2,000 parts by weight
of water at a temperature of about 90 degrees
centigrade for so long as no more free chromic acid
can be identified. After cooling, the former raw
camphor is separated from the adhering benzoic
acid by boiling with alkalies, and is further purified
in the usual way.

There are a great many patented processes us-
ing the hydrochloride as a basis. One decomposes
the hydrochloride with phenols, etc., and oxidizes
the camphene in the usual manner.

Another dries the turpentine with calcium carbid
and then treats slowly with dry H Cl gas at 30 de-
grees C. The compound thus formed is heated to
180 degrees C. with a metal and oxidizing agent,
such as zinc and barium peroxide and sodium anJ

142

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

peroxide. It is stated that when manganese diox-
ide is used alone no metal is necessary.

Also from camphene when treated with chromic
acid mixture at 180 degrees, ozonide (do Hie Os)
is formed, and this treated with water loses oxygen
to form a lactone, camphenolide, and by heating
this compound in presence of water, camphor is
formed.

Terpine Hydrate do His (OH) 2 + H 2 O The
following is Hempel's method of production: A
mixture of eight parts of turpentine oil, two parts
of alcohol and two parts of nitric acid of sp. gr.
1.255 is well mixed and placed in flat basins. After
standing for a few days the mother liquor is poured
off from the crystals of terpine hydrate, and neu-
tralized with an alkali, after which a second crop
of crystals separate. Terpine hydrate can be found
in any pharmacy.

Cineole do His O. This is found in the oil of
eucalyptus and other oils. In making the above
compound (terpine hydrate) the mother liquor is
found to contain this product. Its formation is
probably due to the action of the dilute acid, on
terpine hydrate and terpineol. By distilling the
mother liquor from the manufacture of terpine hy-
drate with steam and cooling to a low tempera-
ture the oil found in the distillate, the cineole will
separate, or by treating the distilled oil with con-
centrated phosphoric acid and neutralizing the re-
sulting compound with an alkali cineole will be
produced. Cineole is a liquid with an odor resemb-
ling camphor. It has a specific gravity 0.930 at 15
degrees C. and a refractive index, N D = 1.45961 at
17 degrees.

Terpineol do HIT O H. It has been mentioned
that the yellow oil left after distilling the turpen-
tine from the crude oil from the steam distillation
of pine wood may be a terpineol. There are three
of these compounds recognized and one form is
solid. Terpineol is produced from terpine hydrate
by the action of dilute acids. It may also be pro-
duced by the action of formic acid on geraniol at
a temperature of 15 degrees to 20 degrees. The

terpinyl formate formed is changed to terpineol by
hydrolysis. Terpineol is found in many oils.

A more extended description of these derivatives
cannot be given here. They are given to illustrate
the possibilities of utilizing the turpentine if the
market prejudice continues to exist.

Rosin Derivatives. It has been stated that the
rosin can be employed in many ways, one of which
is by distilling it for other products. The action
of heat on rosin should be known by a pine wood
distiller, so the following methods are given:

A still or retort may be a vertically placed
wrought iron cylinder, or the cylinder may be
placed horizontally. Some use a regular still shaped
like a coal tar still. Whatever shape is used is
connected with a suitable copper condenser and
heated by means of a direct fire. The size of the
still varies, but usually is large enough to contain
fifty to seventy barrels of rosin.

The flow commences in about one to one and a
half hours after firing, and continues until there
only remains in the still a charry mass resembling
coal. The distillation period covers a space of about
twenty-four hours.

The best oil is obtained between the fifth and
twenty-second hours running, and is of a pale yel-
lowish brown color. It then begins to darken, and
after an hour or an hour and a half the result is a

very black gumming oil. The firing is generally

v
stopped before this time on account of the difficulty

in removing the residuum from the bottom of the
still.

According to Renard, that portion of the distil-
late boiling under 360 degrees C. is called rosin
spirit and that which boils above 360 degrees C. is
called rosin oil. This point is also marked by the
falling off in the quantity of the distillate and by
the specific gravity of the distillate showing about
.951. The residuum when not completely charred is
called pitch and the last product coke. The gas
produced is very heavy and a powerful anaesthetic,
containing carbonic oxides, ethylene, butylene and
pentine.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

143

The products from a seventy-barrel still are given
below:

Name of product. Amounts Yield %

Rosin spirit 60-70 gals. 3.1

Rosin oil 1600 gal's. 85.1

Coke 600-700 gals. 3.9

Acid and water 40-50 gals. 2.5

Gas and loss 5.4

The yield from an actual run made at a plant
in Pennsylvania were as follows:

Amount of rosin 5650 Ibs. Per ct.

Naphtha or spirit about 100 Ibs. approx. 1.75

Raw oil or rosin oil about 4960 Ibs. approx. 87.50

Water about 47 Ibs. approx. 0.80

Pitch about 210 Ibs. approx. 3.76

Gase's, loss, etc about 350 Ibs. approx. 6.20

Apparently, this run shows more oil and less
spirit than the seventy-barrel charge, but the raw
oil upon boiling gave off a^out 6.2 per cent of wa-
ter and naphtha.

In Russian plants about l l / 2 Per cent of lime is
added to the rosin in the still.

The pi-ne oil or rosin spirit is refined in a man-
ner very similar to turpentine, by simple washing
with water and redistilling once or twice. Some-
times caustic soda, or other alkali is added before
distilling, in order to remove rosin oils and acid.
Most of the rosin oil on the market is obtained by
one distillation. It is improved by redistilling in
the same manner as it was obtained. Sometimes
the oil is distilled three times after coming from
the first still, each grade being known as first (from
the rosin), second, third and fourth run.

Formerly gas of high quality was made from the
rosin, 100 Ibs. furnishing 1,300 cu. ft. Rosin spirit
is used as a substitute for the oil of turpentine
and is known as pinolene and pine oil.

Rosin oil is about one-fourth soluble in soda so-
lution, the other three-quarters being comprised
largely of hydrocarbons (above 360 degrees C.).

To make rosin grease, a smooth cream of slacked
lime and water is first prepared and a small por-
tion of the oil is mixed with this in the proportion
of about four parts of oil to three parts of slacked
lime. Oil is then added to the greasy semi-solid

mass until of the required consistency. The fin-
ished grease is often composed of about 1 part of
lime to 20 to 25 of oil. Various terms are applieJ
to crude oil, such as blue, green, red, kidney and
heavy, according to the characteristics thereof.

The pitch formed by the destructive distillation
of rosin, as well as that made by boiling down tar.
is the ordinary pitch of commerce. Rosin pitch i&
different from tar pitch in color, properties and
composition, yet it is near enough like it for most
practical purposes. It is yellowish brown, brittle,
compact, easily crumbling between the fingers. Its
specific gravity is 1.09 and it melts at 68 degrees
C. It loses 82% per cent on heating, leaving a
spongy, soft coke. It has an odor of rosin when
heated. It is soluble in benzine and pyridin.

Wood Residues.

Oxalic Acid. The action of strong alkalies upon
wood is to convert the cellulose into oxalic acid,
which combines with the alkali to form an oxalate.
There are several methods of making oxalic acid
by this general process, varying in the proportion
and kind of alkali used and the method of convert-
ing the resulting oxalate into oxalic acid. A mix-
ture of caustic potash and caustic soda, 40 parts
K O H and 60 parts of Na O H, seems to be the
cheapest proportion of alkali. Soft woods give the
larger yield, thin layers are better than thick lay-
ers. It would seem to be better to use those pro-
portions of wood and alkali as would give the larg-
est percentage of oxalic acid as compared with the
amount of alkali used, but difficulties in the work-
ing of the process allow of not more than 50 parts
of sawdust to 100 of alkali. The oxalic acid is
formed chiefly from the cellulose of the wood and
not from the lignin.

A detailed description of the making of oxalic
acid can be found elsewhere. A general descrip-
tion of one process only will be given here.

Fine sawdust is gradually added to a strong so-
lution of iy 2 parts caustic potash and one part caus-
tic soda, contained in iron pans. The mixture is
then evaporated with constant stirring so as to
obtain a moist, powdery residue. At first only

144

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

water is removed but gradually the mass turns
darker and the wood begins to decompose and emit
a pungent odor. At a temperature of about 180
C. the mass becomes a greenish yellow. The tem-
perature should be gradually raised .to about 240
C. and held there until the wood is dissolved, the
total time being about six hours. The resulting
material consists of a mixture of sodium and potas-
sium oxalates and carbonates with some impurities
from the decomposition of the wood, which gives it
a distinct color.

To extract the oxalate the material is thrown
into iron filter boxes with wire gauge false bot-
toms, and the potassium washed out with water
drawn through the mass by means of a vacuum
pump. The residue consists of sodium oxalate,

from wood has long been attempted. When cellu-
lose is treated with dilute acid it is converted into
a fermentable sugar. Soft woods are the best, as
they contain relatively more cellulose. So far, a
great many difficulties have been encountered in
the practical manufacture of spirits which have not
been entirely overcome. The acid used may be
suitable for the production of the bugar, but when
the acid is neutralized with lime the resulting prod-
uct interferes with the fermenting; when sulphuric
acid is used it seems to prevent, in a measure, the
conversion of the cellulose into alcohol, although
the calcium sulphate formed does not interfere
with the fermentation. . The following conditions
seem to be necessary to obtain the best results
with ordinary mineral acids and soft woods:

Wood Cellulose (bisulphite)

Proportion of total liquiu 6 times \\ t. of cellulose

Concentration of acid 0.5 per cent H 2 SO*

Pressure 10 atmospheres

Duration of digestion 1% hours

Yield sugar (Fehling's test) 41 per cent

Fermentation Free

Yield of alcohol from sugar 70% of theoretical

Pine Wood.
5 times wt. of wood
0.5% H 2 SO 4
9 atmospheres
15 minutes
20% of wood
Variable
60% highest

which is decomposed by heating with milk of lime
in an iron pan supplied with a horizontal stirrer,.
calcium oxalate and caustic soda being formed. By
evaporating the soda lye it can be used again. The
calcium oxalate after it has been washed with wa-
ter is decomposed by sulphuric acid in wooden vats
lined with lead.

The potash salts washed out from the crude
oxalate in the first operation are also boiled with
lime to recover the caustic potash, which is also
used again. The oxalic acid formed by decompos-
ing the calcium oxalate with sulphuric acid is
evaporated and crystallized repeatedly in lead pans
until sufficiently free from sulphuric acid. The
mother liquor mixed with more sulphuric acid is
used to decompose more calcium oxalate.

Ethyl Alcohol. The preparation of grain alcohol

Under properly controlled conditions, one long
ton of wood should yield a little over 17 gallons
of absolute alcohol.

The variation in the fermentation of sugars is
due to the presence of pentoses, which are not fer-
mentable, the hexoses only being decomposed by
the yeast.

One experimenter using European pine sawdust
made only seven gallons of absolute alcohol from
a short ton.

Another, working on a large scale, succeeded in
obtaining about 19 gallons of absolute alcohol from
a long ton of sawdust containing 20 per cent
moisture, equal to nearly 24 gallons to the ton of
dry sawdust. The quality of the sawdust is said
to be most satisfactory, there being no turpentine
flavor or odor.

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

145

A process for making alcohol on this principle
proposes to use sulphurous acid instead of sul-
phuric acid, or other mineral acid previously used.
This process is known as Classen's process. Sul-
phurous acid (formed by passing sulphuric dioxide
into water) easily loses this sulphur dioxide when
heated, consequently when wood is treated with
this acid and sugar formed the acid can be decom-
posed by heat and the sugar solution left ready
for fermentation and containing nothing to seri-
ously interfere with the fermentation process. The
sulphur dioxide formed by the decomposition of
the sulphurous acid can be recovered by passing
it through water.

A company with a large capital is attempting to
utilize pine wood sawdust in this manner at Hat-
tiesburg, Miss. The author has not attempted to
obtain the details of the process as carried out by
this company, and has no information as to the
success of the venture.

The general principles of the Classen process are
known, and can be briefly stated.

The steps in the process are as follows:

1. The manufacture of the sulphurous acid,
which' is done by simply passing sulphur dioxide
gas into water. This gas can be made by burning
sulphur in suitable receptacles or from pyrites.

2. The treatment of the wood with the weak sul-
phurous acid, under pressure in a steam jacketed
rotary digester.

3. The blowing off of the gas and steam from
the digester to recover the acid.

4. The removal of the treated sawdust into
leaching or exhausting vats, where the sugar is
washed out with water.

5. The neutralizing of the sugar solution thus
produced by means of carbonate of lime or other
alkali.

6. The fermenting of the sugar solution.

7. The distilling of the alcohol as ordinarily
carried out in distilleries.

The conditions of working should be carried out
very closely. An acid solution of about one-third
the weight of sawdust is used in the digester. The
digester is slowly turned and the steam in the out-

side jacket heats the contents of the digester to
approximately 295 degrees Fah. The pressure rises
to 100 Ibs., or more, to the square inch, and is
maintained for about three hours. By the action
of the acid some of the cellulose is changed to
sugar. By blowing out the steam and acid into ab-
sorbing tanks 75 to 80 per cent of the acid is re-
covered.

To extract the sugar from the treated sawdust,
the material is removed from the digester and
put into a series of tanks similar to a diffusion
battery. Here fresh water enters the tank con-
taining residue with a small amount of sugar, and
then passes to another containing residue with
a larger proportion of sugar, and so on until the
tank containing the material fresh from the diges-
ter is reached, from whence it passes to the neu-
tralizing vats. In this manner the sugar is ex-
tracted from the treated sawdust with the use of
but little water, and makes a much stronger sugar
solution than if each tank was washed separately.
Generally, the contents of each tank is washed ten
times before removing the residue.

A yield of 450 to 500 Ibs. of sugar, about 70 to 90
per cent of which is fermentable, is claimed as the
yield from a long ton of dry sawdust. This sugar
is in a dilute acid solution, which must be nearly
neutralized so that the acid will not affect the
action of the yeast which is added to the solution,
to cause alcoholic fermentation. This neutralizing
and fermenting is done in suitable tanks and vats.
The fermenting must be done at the proper tem-
perature and when finished the "mash" is distilled
in column stills. The yield is claimed to be 25
gallons of absolute alcohol per long ton of dry
sawdust.

The residue, consisting chiefly of lignin and oth-
er matter not acted upon by the acid, and amount-
ing from two-thirds to three-quarters of the volume
of the original wood, can be used for fuel, or other-
wise treated. When sawdust is acted upon by
acids it loses its elasticity and consequently can
be easily moulded into briquettes, which can be
used for fuel or destructively distilled.
Whether the process will be successful or not

146

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

remains to be seen. It requires careful attention
to details to obtain the best results.

Tar and Derivatives. The chief derivatives from
tar would be the products of distillation. The
products of the destructive distillation of tar have
been mentioned, and in the first part of this chap-
ter a table is given showing the amount of the
various products obtained by distillation of various
kinds of tar.

The distilling operation is smilar in all cases,
the yield of the different products varying accord-
ing to the quality of the tar. In distilling pine
tar from retorts the light oils should first be re-
moved by steam and the tar remaining treated be-
fore distillation by washing with lime water to re-
move acid. Of course, this acid can be distilled
off if desired, thus making the use of lime unnec-
essary.

Starting with neutral and water free tar, the tar
is placed in a still made of wrought or cast iron,
the latter being preferred for small stills, as the
tar can be easily coked in them if required. These
stills are generally made a little over two-thirds
as high as the diameter and furnished with suit-
able inlet valves at the side near the top and an
outlet pipe at the bottom for withdrawing the hot
pitch. To keep the tar from boiling over, and to
help heat the mass more evenly, a stirrer is pro-
vided. Sometimes the bottom is made concave, so
that the fire can come nearer the middle of the
still. On the top of the still is a spherical head,
from which comes a pipe leading to the condenser.
Usually the still is entirely bricked in to prevent
radiation.

The still is heated very slowly for the first five
or six hours. The best tar contains some water,
and this causes a noise in the still. This water
distills first and is followed by light oil, or oil of
tar, as it is called at the pharmacies. This oil
quickly turns brown on exposure to the air. The
receiver is changed when the sp. gr. of the oil
reaches about 0.98. Following the light oils a
heavy oil comes over, having a sp. gr. of upwards
of 1.01 and a yellowish green color. The distilla-
tions can be continued until nothing but coke re-

mains in the still, but this is so difficult to remove
that it is best to stop with the production of pitch,
which can be drawn out hot from the still, if prop-
er care is taken to prevent it from igniting. This
pitch can be run out on iron plates and broken up
for fuel, or used for similar purposes as coal tar
pitch.

Some make the distillation according to tem-
perature, the oil collected under 150 degrees C. be-
ing called light oil, and that collected above 150
degrees C. is known as heavy oil. Some collect
the light oils up to 240 degrees C. and the heavy
oils between 240 degrees C. and 290 degrees C.,
this latter method not being common.

The oils are often washed with caustic soda and
redistilled, the light oils being used as a substitute
for turpentine. The heavy oil contains most of the
creosote, amounting to about 15-25 per cent in pine
tar oil and about 17 per cent in the creosote oil
of the fir, being in the latter case 5 per cent of
the tar. The usual method of obtaining creosote
is to treat the heavy oil with strong lye of about
1.20 sp. gr. Usually a small sample is treated
first, in order to determine about how much soda
is needed. This alkaline solution is drawn off from
the remaining oil. Often both oils are mixed after
neutralizing with the soda, and then rectified by
distillation. The receiver is changed as soon as
the temperature rises above 302 degrees F., and is
changed again when the temperature rises above
482 degrees F. Some take the fraction, between
150 degrees and 250 degrees.

The rectification and treatment with soda is re-
peated many times in some cases, but finally the
light oil is collected separately from /he heavier.
The light oils thus produced contain mostly xylol,
but also eupion and kapnomar; the heavy oil con-
tains the paraffin.

The alkaline liquors have absorbed the creosote.
These liquors are then boiled in an open pan to
expel hydrocarbons, and when cooled saturated
with sulphuric acid and allowed to repose. The
fluid separated thereby is creosote. This is some-
times again dissolved in alkali and reprecipitated
with sulphuric acid until entirely soluble in caus-

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

147

tic soda. In either case it should afterwards be
distilled and the middle portions, collected between
200 degrees and and 220 degrees C., are called
commercial wood creosote. To further purify it,
it is treated with % to l / 2 per cent of potassium
bichromate and y 2 to 1 per cent of sulphuric acid,
allowed to repose twenty-four hours and again dis-
tilled. The distillation is generally carried on in
glass vessels, the portions between 205 degrees
and 220 degrees C. being collected separately.

Wood creosote is a colorless, highly refracting
oil with a sp. gr. of 1.03 to 1.087, and a boiling
point from 205 degrees to 222 degrees C. Stock-
holm creosote from pine tar consists chiefly of

fOCHs
creosol C Hs (C Hs) \ OH Wood tar creosote

does not solidify with moderate cold; it is a pow-
erful disinfectant, but does not disintegrate like
phenol is apt to do. It is insoluble in water, but

readily so in ether, alcohol, glacial acetic acid,
chloroform, benzine and carbon bisulphide. Fif-
teen parts of wood creosote with ten of collodion
dissolve to a clear solution, whereas under the
same conditions coal tar creosote forms a gelatin-
ous mass. Crude wood creosote contains, in addi-
tion to creosol, jphloral, guaiacol, etc., eupion,
kapnomar, picamar, cedriret, pyrene, pittacal, etc.
and these can be recovered from wood tar. Such
are not commercially important.

The pitch formed in the still by distilling the
tar comprises a large bulk of the original tar.
There is still left about 88 per cent of volatile
matter, which can be removed by heating, leaving
12 per cent of soft friable coke.

This pitch is soluble to a large extent in alco-
hol, potash, benzine, etc. It contains some vola-
tile fatty acids and hydrocarbons. See Pitch,
Chapter X.

CHAPTER XIII.

CHEMICAL CONTROL OF A PLANT FOR THE DISTILLATION OF WOOD.

The destructive distillation of wood is as much
a chemical operation as the distillation of petro-
leum. Very few manufacturing industries using
destructive distillation processes employ chemists.
One of the best known of these industries is 'the
coal gas manufacture and it is only recently that
chemists have been used at these plants even
in large cities. One reason is that the field has
been occupied more by engineers rather than
chemists.

With the steam process for obtaining turpentine,
the services of a chemist are not so essential
unless derivatives are to be made, but with large
destructive distillation plants, one chemist or sev-
eral could be of great service in the operation of
the plant. At present very few chemists are ac-
quainted with the details of the operation of wood
distilling plants and this lack of familiarity on
their part has been pointed out to their disad-
vantage, by the men who have been in control of
these plants. But put an experienced chemist in
a position to learn the details of the business, and
his general knowledge will soon place him far in
advance of the men engaged in the business who
are now familiar with it. This superiority has been
shown markedly in other lines of chemical industry
and it is not to be wondered at, as this is what
chemists have been trained for. The pine wood
distilling business is not attractive to chemists as
it has not proved to be a very paying industry.

The following scheme of chemical control is not
considered to be anything but suggestive. If plants
of any size should get on a paying basis, and a
laboratory established, this plan could be modified
to suit conditions or another used in its place. The
arrangement naturally falls under the given head-
ings.

Measurements.

Wood. This should be weighed in the car or
wagon or, if desired, measured, but weighing is to

be preferred. When sawdust or ground wood is
used, it should be measured by the capacity of the
retorts and if weight is desired, the approximate
density can be taken by sample. The trash in a
load should be weighed once in a while to deter-
mine the per cent in this form, particularly when
long wood is used.

Crude Turpentine. This should be weighed also
to get accurate results, but for technical purposes
it can be measured in tanks of known capacity,
which are accurately gauged. When sent to the
still the temperature should be taken, the specific
gravity and a sample of eacu still. charge.

Water Separated from the orude Turpentine.
It is better to measure this through a meter, the
specific gravity and temperature being taken at
suitable intervals. A sample should be taken also
so as to be able to determine the amount of oil
that may escape.

Caustic Liquor. This should be kept in a special
air-tight tank of known capacity. The caustic
should be weighed and the water measured before
mixing. In using, the strength having been pre-
viously determined by testing a sample, the tem-
perature being known, the quantity of liquor used
should be noted by the gauge.

Refined Turps. As these come from the still, the
water settling out can be measured and the tem-
perature taken. A. regular sample should be taken
to determine any loss in oil. The oils can be
measured from each run in the separating tanks
when barreled or when pumped, the temperature
being taken.

Condensing Water. The water from each con-
denser can be measured when the exact working
of each one is to be ascertained. The entire con-
densing water used may be measured by the work
of the pumps or by sending through meters.

Tarry Products and Pyroligneous Acid. These
products from the retort can be determined by

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

149

volume, a large sample being taken and the tem-
perature noted. This should be done before any
great settling takes place. The workings of each
separate retort should be gauged as far as pos-
sible.

After settling, if acetate is to be made, the pyro-
ligneous acid can be measured and sampled, the
temperature taken and the acid sent to the neu-
tralized tank. If acetate is not made, the acid
should be sampled and sample kept to test the
tar content and the acid run off. The tar oil can
be treated similarly, being sure in all cases to
note the temperature.

Stills. Measure all liquors going into stills and
sample same and take temperature. The condensed
water and condensing water should be measured
as used.

Tar. Should be weighed when barreled or when
shipped in tank cars. At other times measure and
sample, noting the temperature.

Other Products. The same general rule applies
to them. Weigh the solids and measure the liq-
uids, in all cases sampling and noting the temper-
ature.

Sampling.

Wood. The sampling of wood is a very difficult
operation. For long wood, perhaps the best way
would be to take about three sticks of what ap-
peared to be average wood and pass them through
a hog and thoroughly mix the sample thus pro-
duced. It should be quickly covered and kept in
an air-tight vessel. Hogged wood or sawdust can
be sampled as it enters the retort.

Crude Turpentine. In bulk a sample can be ob-
tained by simply filling a suitable bottle and cork-
ing it. To sample a single retort which is not
supplied with a separate receiver, it can be ar-
ranged so that a small part of the distillate can
flow into a suitable bottle. A sample should be
taken or each charge entering the still.

Other Products. All the other liquid products
can be sampled like the crude turpentine.

Liquors in Settling Vats. When the liquors are
of such a nature that a marked separation will

not take place, a special device is necessary for
sampling. A good way is to get a long glass tube
about one inch or more in diameter and of suf-
ficient length to reach the bottom of the tank. One
end should be fitted with a piece of rubber. By
inserting this tube into the liquid at different
levels, a number of samples can be drawn out and
collected in one bottle and shaken together.

In very large tanks valves can be placed at in-
tervals on the tanks and the samples drawn from
each and mixed. In this case, it is necessary to
catch a large sample and return it to the tank
before a suitable sample can be obtained from
each valve.

Gas. Samples can be drawn as often as desired
by the regular methods. The flue gases should be
watched in starting new retorts so as to enable
the fireman to learn their peculiarities, if any.

Standardizing Apparatus.

Balances and Weights. Two balances should be
used, one sensitive to five milligrams and the other
very sensitive, turning when loaded with one or
two-tenths of a milligram.

Test the balance arms by balancing weights
against each other and then changing them to
the opposite pans, where they should again balance
each other. The weights, of course, should be stan~-
ard and have a correct relation between them and
the balance and between each other.

Polariscopes. A good polariscope should be used
showing left and right-handed scales. The zero
point should be set properly and all errors on the
scale noted. The scale can be checked by stand-
ard quartz plates, and these latter themselves
checked once in a while.

Refractometer. This instrument as well as the
polariscope should be standardized at 20 degrees
C. Probably for technical use one with a standard
at 30 degrees C. would be better on account of the
heat in summer. Generally a form similar to
Abbe's would be suitable. The basis used is dis-
tilled water with its reading at the standardizing
temperature.

Thermometers. These should be compared with

150

THE UTILIZATION OF WOOD WASTE, BY DISTILLATION.

a standard thermometer which has been officially
corrected.

Hydrometers or other form of spindles. These
can be checked by means of the pycnometer.

Flasks. These can be standardized to the polar-
iscope temperature. This temperature should be
used for everything. By marking a 100 c. c. pi-
pette so as it will deliver exactly 100 c. c. at the
given temperature, all the flasks can be standard-
ized by means of this. Otherwise, weigh with the
proper amount of water, using 1 gram in vacuo at
4 degrees C. equal to 1 c. c.

Water Meters. These should be standardized by
weighing a quantity of water passed through.

Tanks. The contents of these can be most ac-
curately determined by filling from a barrel placed
on a platform scale, weighing all water admitted
and making correction for temperature. Other-
wise, calculate the cubic contents from measure-
ments and allow for the temperature.

Burettes and other Volumetric Apparatus. The
same temperature should be used as for flasks and
contents accurately determined by weighing the
water delivered. When one piece is properly stand-
ardized it can be used to standardize the others.

ANALYSIS.
Turpentine.

For the analysis of turpentine the following
method is given by the Bureau of Supplies and
Accounts, Navy Department, May, 1903.

1. The turpentine must be properly prepared
distillate of the proper kinds of pitch or pitch pine,
unmixed with any other substances; it must be
pure, sweet, clear and water white.

2. A single drop allowed to fall on white paper
must completely evaporate at a temperature of 70
degrees Fah. without leaving a stain.

3. The specific gravity must not be less than
0.862 or greater than 0.872 at a temperature of 60
degrees Fah.

4. When subjected to distillation, not less than
95 per cent of the liquid should pass over between
the temperatures of 308 degrees Fah. and 330 de-

grees Fah., and the residue should show nothing
but the heavier ingredients of pure spirits of tur-
pentine.

5. A definite quantity of the turpentine is to
be put in an open dish to evaporate, and the tem-
perature of the dish maintained at 212 degrees
Fah.; if a residue greater than 2 per cent of
the quantity remains on the dish it will constitute a
cause for rejection.

6. Flash Tests. An open tester is to be filled
within one-fourth of an inch of its rim with the
turpentine, which may be drawn at will from any
one can of the lot offered under the proposal. The
tester thus filled will be floated on water con-
tained in a metal receptacle. The temperature ol
the water will be gradually and steadily raised from
its normal temperature of about 60 degrees Fah.
by applying a gas or spirit flame under the recep-
tacle; the temperature of the water is to be in-
creased at the uniform rate of 2 degrees Fah. per
minute. The taper should consist of a fine linen
or cotton twine (which burns with a steady flame)
unsaturated with any substance. When lighted it
is to be used at every increase of 1 degree tem-
perature, beginning at 100 degrees Fah. It is to
be drawn horizontally over the surface of the tur-
pentine and on a level with the rim of the tester.
The temperature will be determined by placing a
thermometer in the turpentine contained in the
tester so that the bulb will be wholly immersed in
the liquid. The turpentine must not flash below
105 degrees Fah.

7. Sulphuric Acid Test. Into a 30 cubic centi-
meter tube graduated to tenths, put 6 cubic cen-
timeters of the spirits of turpentine to be exam-
ined. Hold the tube under the spigot and then
slowly fill it nearly to the top of the graduation
with concentrated oil of vitriol. Allow the whole
mass to become cool and then cork the tube and
mix by shaking the tube well, cooling with water
during the operation, if necessary. Set the tube
vertical and allow it to stand at the ordinary tem-
perature of the room not less than half an hour.
The amount of clear layer above the mass shows
whether the material passes test or not. If more

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

151

than 6 per cent of the material remains undis-
solved in the acid this will constitute cause for
rejection.

A test of turpentine for petroleum oils formerly
used was to agitate the oil with sulphuric acid
(two parts to one of water) then distill in a cur-
rent of steam. Treat the distillate of oil with sul-
phuric acid (four parts acid and one of water) and
again distill; any oil coming over being petroleum.

The chief difference between wood turpentine
and gum turpentine, as now produced, is in the dis-
tillation test, but both oils vary much in their
properties. Whether it is advisable to adhere to
the standard set for orchard turpentine in testing
wood turpentine is doubtful. Perhaps it would be
advisable to make a new standard of requirements
for wood spirits of turpentine and make all manu-
fac'urers adhere to it.

The chief concern of dealers is that oil of tur-
pentine contains no cheap adulterations. The se-
ries of tests given above will locate any petroleum
admixtures.

Of the various special tests, only a brief outline
will be herein given. Utz observes the refractive
index and treats with iodine water and observes
the color as compared with a known sample sim-
ilarly treated. H'ersfeld treats with concentrated
sulphuric acid, then with fuming sulphuric acid,
only a small definite portion of oil remains; any
excess representing; adulteration. The determina-
tion of the refractive index is made on small frac-
tions of the distilled oil, before treatment with sul-
phuric acid. McCandless makes three successive
polymerizations with concentrated sulphuric acid
once and fuming acid twice, distilling after each
treatment in a current of steam and testing the
distilled oil in the refractometer. Worstall treats
with iodine under exact conditions. Hinsdale evap-
orates a weighed quantity of known turpentine in
one watch glass and the same amount of unknown
sample in another and places them in a water bath
at 170 degrees Fah. until the known sample evap-
orates, the residue remaining in the other being
adulterants. Hall treats with sulphuric acid under
exact conditions, and observes the rise in tempera-

ture, similarly to the Maumene test for vegetable
oils.

Hydrochloric acid is stated to turn wood turpen-
tine black, but such is not the case with well-
refined samples.

A test for rosin spirit in wood turpentine is given
by Valenta as follows: Mix one to two parts of
a six per cent solution of iodine in carbon bisul-
phide or carbon tetrachloride and heat on a water
bath. A green to olive green is produced by pino-
line or rosin spirit and none by wood spirit or tur-
pentine. For a mixture of oil of turpentine, wood
turpentine and rosin spirit take equal volumes of
the mixture and a one per cent solution of auric
chloride in a test tube and shake, heat one minute
in water bath and shake again. Pure oil of tur-
pentine shows separation of gold in oily layer only
but when the other substances are present the
aqueous solution is completely decolorized.

Wood Oil. No satisfactory tests are given for
this oil, as it is of such a varying composition as
now produced.

At those plants which wish to make a standard
certain tests might be applied. These would have
to be determined by the chemist in charge and a
standard set.

The following plan might be of service. Test for
specific gravity. Take the iodine value, the spe-
cific rotary power and refractive index (if too dark
dissolve in water white petroleum), take the flash
test and fire test, determine boiling point, try tests
given under turpentine, and for creosote oils, de-
termine the amount of creosote by any of the regu-
lar methods. From these data a definite grade
may be established at each plant.

A method of investigation to determine the con-
stitution of wood oil is to be found in the Ameri-
can Chemical Journal, Vol. 25, No. 1. This cannot
be given here, as it cannot very well be carried
out in a technical laboratory.

Tar Oil. The only test that is necessary to
make on this oil would be for the presence of
pyroligneous acid. It has been found that the
pyroligneous acid and tar do not always separate
distinctly into two layers. The sample of the mix-

152

THE UTILIZATION OP WOOD WASTE BY DISTILLATION.

ture is taken as it comes over, and if it does not
separate into distinct layers, two methods may be
used to give approximate results as to the amount
of oil and acid in the mixture.

The first would be to thoroughly mix the sample
and then take out a definite amount, say 25 c. c.,
put in a graduating cylinder and dilute to 500 c. c.
(or more, according to the rate of separation).
When thoroughly separated the amount of tar oil
can be read off and the pyroligneous acid consid-
ered to be the difference between the amount of
tar oil and the original amount. For greater ac-
curacy the bottom part of the graduated cylinder
could be made of small bore and mounted on a flat
base.

The second method consists in placing a sample
in a graduated flask of a centrifugal tester, and
reading the percentage of tar or acid from the
scale after revolving. In most cases a special flask
would need be used, as over 50 per cent of the
distillate is sometimes acid; the centrifugal tester,
though, would be the best device to use for the
separation.

In taking stock, it would be necessary to know
the amount of tar in the tar oil.

To do this a sample of the mixed liquor or the
tar oil itself after separating the acid, should be
placed in a distilling flask and the light wood oils
distilled by means of a current of steam. The
residual tar can then be weighed and the light
oils measured. The distillation should continue no
longer than the degree to which it would be car-
ried out at the plant. It might also be distilled
with water and the light oils measured and the
difference considered as tar or the tar dried and
weighed.

Measuring the oils is not a very safe way, as
they are soluble in water to a considerable extent.

Tar. When the tar contains water a quick tech-
nical way would be to separate it in a centrifugal
tester and read off the amount.

One test for tar proper has already been given
in part. It consists in fractionally distilling the
tar in a distilling flask with a short head. Care
should be used at first, as any water contained

therein causes severe bumping. The specifications
are:

Distilling under 150 degrees C., 9.70 per cent.

Distilling between 150-350 degrees, 42.61 per cent.

Distilling between 350-363 degrees, 26.62 per cent.

Coke, 21.07 per cent.

Tar varies so much that certain definite tests
like the above could be only approximated. The
chief methods for judging tar are in regard to the
color, weight and viscosity. The color can be de-
termined by placing a drop on a sheet of white
paper; the spot should be light brown. The spe-
cific gravity varies from 1.05 to 1.12. The thick-
ness or viscosity is generally judged by the eye.
No standard can be set for this property, but ar-
rangements could be made to sell tar within cer-
tain limits as determined by a viscosimeter. An-
other test, to distinguish between some grades
of retort tar is to pour a drop on the sur-
face of a piece of smooth white poplar or deal
wood and note the relative length of time it takes
for the sample to darken on exposure to the air,
as compared with a sample of known quality.

Acetates and Pyroligneous Acid.

To determine the acid, reckoned as acetic acid,
in pyroligneous acid, several methods are given.
One method is to take 25 c. c. and dilute with
1,000 c. c. or more of distilled water, titrate with
normal alkali, using phenolphthalein as an indi-
cator, and calculate the percentage. Often with
pine wood acid, the end point is too indistinct and
another method must be used.

C. Mohr gives the following method: Weigh off
10 grams of wood vinegar, heat in a beaker with
about 3 grams of pure barium carbonate (test the
carbonate) until effervescence ceases, and filter.
The solution of barium acetate is strongly colored,
but the carbonate remaining undissolved fvery
little. The residue after washing is dried and
weighed and the quantity of acetic acid present
calculated; each gram of dissolved carbonate cor-
responding to 0.809 gram of acetic acid or 10
grams of wood vinegar contains 6.09 per cent.

It is quicker to treat the undissolved carbonate

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

153

with an excess of normal nitric acid and titrate
back with normal soda, using litmus as an indica-
tor.

Instead of barium carbonate, Mohr also uses
precipitated moist calcium carbonate, the alkalin-
ity of which is determined. This is added to the
wood acid in excess and the mixture boiled to ex-
pel C Oz, then filtered and treated as before.

Acetates.

Acetate of lime, such as the brown and gray,
are tested for acetic acid in various ways. Two
methods will be given.

Stillwell and Cladding's method is as follows:

A 100 to 120 c. c. retort, the tubulure of which
carries a small funnel fitted in with a rubber stop-
per, and the neck of the funnel stopped tightly
with a glass rod shod with elastic tube, is sup-
ported upon a stand in such a way that its neck
(the retort neck) inclines upwards at about 45
degrees; the end of the neck is drawn out and
bent so as to fit into the condenser by help of an
elastic tube. The greater part of the retort neck
is coated with flannel, so as to prevent too much
condensation.

One gram of the sample being placed in the re-
tort, 10 c. c. of a 40 per cent solution of Pz Os
are added, together with as much water as will
make about 50 c. c. A small naked flame is used
and if carefully manipulated, the distillation may
be carried on to near dryness without endangering
the retort. After the first operation the retort
is allowed to cool somewhat, then 50 c. c. of hot
water added through the funnel, another distilla-
tion made as before, and the same repeated a third
time, which will suffice to carry over all the acetic
acid. The distillate is then titrated with alkali
and phenolphthalein.

The following is the method of Grimshaw, taken
from Allen's Organic Analysis, as given by Sutton:

Method of Procedure: 10 grams of the sample
are treated with water and an excess of sodium
bisulphate (Na H SO<) the mixture diluted to
definite volume, filtered and a measured portion
of the filtrate titrated with standard alkali; a sim-

ilar portion meanwhile is evaporated to dryness
with repeated moistenings with water, to drive off
all free acetic acid. The residue is dissolved and
titrated with standard alkali, when the difference
between the volume now required and that used
in the original solution will correspond to the
acetic acid in the sample. Litmus paper is the
proper indicator.

Wood.

The only tests necessary to be made on wood
are those which determine its content of water
and resin.

Sampling is the most difficult part. If possible,
a few average sticks from a cord lot should be
passed through a suitable disintegrating machine.
In the absence of this, each stick should be cut
into in several places, and rasped a little at each
place, with a wood rasp. In both cases the finely
divided product should be bottled, so as to pre-
vent the evaporation of moisture.

Moisture.

Determine this by heating a sample of two
grams or more in an air bath kept at 105-110 de-
grees C. Cool in a desiccator and weigh and the
loss in weight indicates thei moisture. This method
is not so very accurate, as the wood is ant to
oxidize slightly, and in fat woods a great deal
of turpentine would escape with the water.

The author knows of no method for testing this
class of wood, but would suggest the following:

Take 2 to 5 grs. of the finely divided wood and
place in a weighing bottle fitted with a tight
ground glass stopper. Make a hole in the stopper
and weld a piece of glass tubing around the open-
ing, then bend the tubing so as to form a U. In
the tube, put pieces of lime or soda lime. Weigh
the stopper and the tube containing the lime, also
weigh the bottle and its contents. Insert the
stopper in the weighing bottle and place the
whole apparatus in an oven heated to about 105-
110 degrees C. Heat for one hour, then with-
draw the apparatus and allow to cool either in a
desiccator or by closing the end of the U tube.

154

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

Weigh each part separately. Repeat until the loss
in weight of the weighing bottle is relatively con-
stant. Then heat the tube containing the lime
to about 200 degrees C. in an air bath or other-
wise; cool and weigh, repeating until the loss in
weight is constant.

The method is based on the following apparent
principles: The first heating drives the water
and any oil over into the tube. The lime fixes the
water. Any oil condensed is driven off by the sec-
ond heating. Slaked lime holds its water of com-
bination even when heated to 250 to 300 degrees C.

The loss in weight of the weighing bottle rep-
resents moisture plus volatile oil. The weight of
the lime tube after the second heating minus its
original weight represents the moisture. The moist-
ure found subtracted from the moisture and oil
lost from the weighing gives the amount of vola-
tile oil. If any volatile oil is found to have passed
over, it should be considered as turpentine and
added to the amount found by distilling the ether
extract.

A method used in determining moisture in ex-
plosives containing volatile oils might also be
used. It consists in treating the ground sample
with calcium carbide in a tube, taking precaution
not to mix the two until the tube is connected
with a gas measuring apparatus. The acetylene
gas formed is measured over salt water and cor-
rections made for temperature and pressure. An
allowance is also to be made for the amount of
moisture retained by the lime formed during the
reaction, as this moisture does not act on the cal-
cium carbide. On this account 1 c. c. acetylene
equals .001725 gr. moisture, instead of .00162 gr.

In making the test the reaction can be hastened
by heating in a water bath to 100 degrees C.

The wood residue from the moisture determina-
tion is placed in a filter cone of a Soxhlet fat ex-
traction apparatus and the cone inserted in the
tube. The tube should then be connected with
the flask. It will be found that in determining the
moisture of fat wood that some of the resin has
exuded from the wood on account of the heat and
flowed to the bottom of the crucible or other con-

tainer used in making the determination. After
removing the wood this resin can be dissolved in
ether and poured upon the cone in the tube. The
apparatus is used as in making an ordinary fat
analysis, the resin being extracted from the wood
and collected in a small flask. The ether is evap-
orated and the flask cooled and weighed. The dif-
ference between this weight and the weight of the
empty flask equals the weight of the extracted
matter. By connecting the flask with a suitable
condenser and carefuly heating it, the turpentine
will distill over. It is better, though, to make this
distillation by simply passing a current of steam
through the extracted resin, and the turpentine
will distil without danger of decomposition of the
resin.

The turpentine can be separated from the water
and weighed or measured. The flask containing
the resin should then be placed in an air bath
until the water is driven off, and then weighed.
The difference between this weight and the weight
of the flask equals the weight of resin. The weight
also serves as a check on the turpentine.

The woody fiber left, after extracting with ether
can be burned in a crucible and the residue
weighed as ash. If desired it can be distilled by
placing it in a glass retort. The retort should
be placed in an air bath, the tube of the retort ex-
tending through an opening in the side and con-
necting with a condenser. The condensed products
can then be collected and separated and each
weighed separately. The charcoal should also be
weighed. The gas can be collected and measured.

The acetic acid in the pyroligneous acid can be
determined by Mohr's method and the wood alco-
hol by the phosphorous diiodide method, given un-
der pyroligneous acid and wood alcohol, respec-
tively.

Determination of real methyl alcohol in wood
spirit (Allen's Org. Analysis, Vol. 1, p. 73).

A dry flask is furnished with a cork fitted with
a tapped funnel or pipette and connected with an
inverted condenser; 15 grams of phosphorous diio-
dide are placed in the flask and 5 c. c. qf the sam-
ple of wood spirit (measured at 15 degrees C.) add-

THH UTILIZATION OF WOOD WASTE BY DISTILLATION.

155

ed slowly, drop by drop, by means of a pipette; 5
c. c. measure hydriodic acid of 1.7 sp. gr. con-
taining in solution 8.5 grams of free iodine is next
added through the pipette. The flask is then
heated to 80 to 90 degrees C. by immersion in hot
water for a few minutes, after which the condenser
is placed in the ordinary position and the contents
of the flask are distilled and collected in a grad-
uated tube. The distillate is shaken wiLh water
and the volume of methyl iodide read off. Correc-
tions of 8 volumes per 1,000 must be made for
the solubility of the methyl iodide in water, and
for the loss due to the vapor which fills the ap-
paratus. This error, which is constant for the
same apparatus, is determined by distilling a
known measure of iodide of methyl, measuring the
distillate and thus ascertaining the loss. Krell
prefers to pass a current of air into the apparatus,
through the pipette, and thus drive out the vapor
of methyl iodide. Under these conditions, 5 c. c.
of pure anhydrous methyl alcohol yields 7.45 c. c.
of the iodide.

By the iodine process any methyl acetate pres-
ent in the sample is converted into iodide and
hence increases the apparent percentage of methyl
alcohol. For most purposes the error thus intro-
duced can be neglected. If desired the quantity
present can be previously determined approximate-
ly by heating a known quantity of the wood spirit
with standard soda and titrating the excess with
standard acid. Forty parts of Na O H neutralized
corresponds to 74 of methyl of acetate, or 32 of
methyl alcohol. The amount of methyl alcohol so
found should be subtracted from the total amount
corresponding to the iodide in order to ascertain
the real amount of methyl alcohol existing as such
in the sample.

When acetone is present it distills over with
the methyl iodide, and it is only by repeated wash-
ing that the distillate can be wholly freed from it.
Bardy and Bordet have constructed a table showing
the diminution in volume undergone by methyl
iodide containing various percentages of acetone by
washing with water. In the absence of the table,
the error caused by the presence of acetone might

be avoided by saponifying the washed distillate
with alcoholic potash evaporating to dryness, dis-
solving the residue in water, acidulating an aliquot
part of the solution with nitric acid, and then pre-
cipitating the iodide by silver nitrate. 235 parts
of iodide of silver represent 32 of methyl alcohol.

Dimethyl acetal also comes over, 5 c. c. of which
yield 5.3 c c.. of methyl iodide. The others are
either soluble in water or are converted into resin-
ous bodies.

For the preparation of the iodide of phosphorous,
15.5 grm. of phosphorous are dissolved in 350 c. c.
of carbon disulphide, and 127 grm. of iodine are
gradually added, the vessel being kept well cooled.
The diiodide separates in crystals, which are dried
in a slightly warm current of air and preserved
in a well-stoppered bottle. A qualitative test for
methyl alcohol given by Mulliken & Scudder con-
sists in plunging a. hot copper spiral into the liquid
to be examined and adding one drop of a solution
of one part resorcin in 200 parts of water, then
pour the solution carefully upon concentrated sul-
phuric acid so as not to mix. After three min-
utes with slight mixing methyl alcohol causes rose
red flocks.

Creosote. There are many substances that go by
the name of creosote. Coal tar creosote and wood
tar creosote are separated by Hagar's method. The
following is an abstract of Allen's description of
Hagar's method:

Three measures of absolute glycerol are mixed
with one measure of water, and the solution used
as a solvent. Treat one measure of the sample in
a Mohr burette with three measures of the diluted
glycerol, and allow the liquid to stand until sep-
aration has occurred. If the creosote be pure, the
volume will remain unchanged. If reduced the gly-
cerol layer is tapped off and the remaining creo-
sote again shaken with three times its measure
of diluted glycerol and the measure again observed,
This second treatment will always suffice for the
removal of the coal tar acids, unless their propor-
tion is very large, and hence the volume of the
residual layer will indicate the proportion of real
wood creosote in the quality of sample taken. The

156

THE UTILIZATION OF WOOD WASTE BY DISTILLATION.

nature of the residual creosote can be verified by
the collodion test (should form a clear solution)
while the coal tar acids can be recovered from the
glycerol solution by filtering it to remove suspend-
ed traces of wood creosote, diluting with water
and agitating with chloroform. On spontaneous
evaporation of the separated chloroform the coal
tar acids are obtained in a condition of sufficient
purity to allow of their positive recognition.

Acetone. The gravimetric determination of this
substance is by means of caustic and iodine. A
volumetric method that can be. used in presence
of ethyl alcohol is given by Sutton, as follows,
modified by Squibb and Kebler. The solutions re-
quired are as follows:

(1) A 6 per cent solution of hydrochloric acid.

(2) A decinomal solution of sodium thiosul-
phate.

(3) Alkaline potassium iodide solution prepared
by dissolving 250 gm. of potassium, 257 gm. of so-
dium hydroxide (by alcohol) in, water, likewise
made up to a litre. After allowing the latter to
stand, 800 c. c. of the clear solution are added to
the liter of potassium iodide.

(4) Sodium hypochlorite solution: 100 gm. of
bleaching powder, (35 per cent) are mixed with 400
c. c. of water; to this is added a hot solution of
120 gm. of crystalized sodium carbonate in 400 c. c.
of water. After cooling, the clear liquor is decant-
ed, the remainder filtered and the filtrate made up
to a litre; to each litre is added 26 c. c. of sodium
hydroxide solution (sp. gr. 1.29).

(5) An aqueous acetone solution containing 1 or
2 per cent of acetone as pure as may be had, say,
99.7 per cent.

(6) Starch solution, prepared by treating 0.125
gr. of starch with 5 c. c. of cold water, then adding
20 c. c. of boiling water, boiling a few minutes,
cooling and adding 2 gm. of sodium bicarbonate.
This starch solution will keep for some weeks.

To 20 c. c. of the potassium iodide solution are

added 10 c. c. of the diluted aqueous acetone, an
excess of the sodium hypochlorite solution is then
run in from a burette and well shaken for a minute.
The mixture is then acidified with the hydro-
chloric acid solution, and while agitated an excess
of sodium thiosulphate solution is run in the mix-
ture, being afterwards allowed to stand a few
minutes. The starch indicator is then added and
the excess of thiosulphate retitrated. The relation
of the sodium hypochlorite solution to the sodium
thiosulphate being known, the percentage of ace-
tone can be readily calculated.

In the above reaction 1 molecule of acetone re-
quires 3 mol. of iodine to four 1 mol. of iodoform.
One atom of available chlorine will liberate one
atom of iodine from the K I in the alkaline solu-
tion, or 1 c. c. will liberate just enough I to make
1 c. c. of the same normal strength as the hypo-
chlorite solution originally was; therefore, by read-
ing the number of c. c. of hypochlorite consumed
as so many c. c. of iodine solution of the same
normal strength, the calculation is reduced to the
basis of iodine. Expressing it as a proportion and
letting y equal the amount of combined I and x
that of acetone, we have (taking I as 126.5)

58
759:58: :y:x or x=y 759 or x=y 0.07641.

Example of calculation 10 c. c. of the acetone
solution containing 1 gm. of the liquid to be anal-
yzed required 14.57 c. c. of iodine solution of same
strength, or combining we have

14.57x0.806x0.1260x.Q7641

1 gm of solution of acetone" 11 ' 351 per cent

Many other methods of analysis of the various
products should be reviewed in order to get a sys-
tematic routine for a wood distilling plant. Of
the methods given, all are recognized as standards
for the particular conditions and products to which
they apply. It is beyond the scope of this work
to give more methods than are herein contained.

CORRECTIONS AND ADDENDA

Table of Contents, Page 118, instead of Steam Plant, It should be Estimates.

Illustrations, Fig. 45 should be Sibbet & McLean's Process and Fig. 53 Copilovich
Process, Page 80.

Page 81, first column, 15th line, shaped should be shape.

Page 32, first column, 2nd line, small should be light.

Page 33, first column. 2nd line, omit "or the retort cool off suddenly."

Page 33, second column, 3()th line, after "condensed," to be more accurate it
should have been stated that in a large pipe a 'slower
motion would take place, thus allowing more time for
the vapors to come in contact with the walls.

Page 39, first column, 29th line, I should be It.

Page 39, first column, 37th line, 3 should be 5.

Page 44, first column, 22nd line, sifter "and the" add entering.

Page 47, first column. 3rd line, P should be D.

Page 47, first , column, 22nd line, omit all to 25th line.

Page, 91, Credit should be given Jackson for the ready means of discharge in
his apparatus.

Page 03, first column, 1st line, c is the opening above grate.

Page 83, second column, 3rd line, "of" should be to find.

Page 105, second column, 5th line, pyroligenous should be pyroligneous.

Page 117, first column, 5th line, collects should be collect.

Page 122, first column, 13th line, methylfurfural should be methylfurfurane.

Page 128, second column, 30th line, after "rosin" put oil.

Page 143, first column, 6th line, in table should read coke 600 to 700 pounds,
not gallons.

Page 144, first column, 14th line, after "potassium" add salts.

Page 144, second column, 3rd line from bottom, the second sawdust should be alcohol.

Page 145, first column, 5th line, "sulphuric" should be sulphur.

Page 152, second column, 42nd line, omit "10 grains of wood vinegar contains 6.0!>
per cent.''

Page 156, first column, 17th line, "decinomal" should be decinormal.

Page 156, first column, 20th line, after "potassium" read in a litre of distilled
water.

Page 156, second column, 14th line, "four" should be form.

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