Yields from the destructive distillation of certain hardwoods

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BULteTIN- Or THE

USDEPARINENT OFAGRCULTURE

No. 129

Contribution from the Forest Service, Henry S. Graves, Forester.

September 10, 1914.

(PROFESSIONAL PAPER.)

YIELDS FROM THE DESTRUCTIVE DISTILLATION
OF CERTAIN HARDWOODS.’

By L. F. Haw ey and R. C. Parmer, Chemists in Forest Products.
PURPOSE OF EXPERIMENTS.

The chief hardwoods used in this country for distillation are beech,
birch, and maple. Only mill and forest waste and trees unmerchant-
able for lumber are now ordinarily used, although some material suit-
able for lumber still finds its way to the distillation plants. Such
southern hardwocds as the oaks, red gum, tupelo, and hickory have
not been important in distillation, and no information has existed in
regard to the amount of the various products which could be obtained
from them. Nor has information been available on the relative value
of the commonly used species, or of the different forms of material,
such as body wood, limbs, and slabs. The investigation here de-
scribed was undertaken in order to supply this information and to
aid in this way the utilization of materials now wasted.

METHOD OF INVESTIGATION.

GENERAL PLAN.

Since conditions of distillation influence the yield of products,
results obtained in the laboratory could not be compared directly
with those obtained in commercial operations. In order to have a
direct comparison between the species commonly used and the ones
which are not, it was therefore necessary to include both classes in the
investigation. -

The various materials were distilled under similar conditions, and
their products analyzed by the same methods. In order to avoid
errors due to differences in yields from different trees of the same
species, in most cases an average sample of material from two or

NovtE.—Gives results of experiments in destructive distillation of hardwoods. Of interest to manufac-
turers of by-products. ~

1 The investigation the results of which are given in this bulletin were conducted at the Forest Prod-
ucts Laboratory, Madison, Wis., maintained in cooperation with the University of Wisconsin.

51595°—14—__1

2 BULLETIN 129, U. S. DEPARTMENT OF AGRICULTURE.

three trees was distilled. Further, the average yields from the heart-
- wood! of several trees were in a few instances compared with the
yields from lumber of the same species. Differences in yields may
also occur in trees of the same species grown in different localities,
and for this reason the results obtained are averaged separately when
more than one locality is represented. At least two distillations
were made of each kind or form of material tested. :

Different forms of wood—such as body wood (wood free from bark),
slabs, limbs, ete.—were distilled, but the proportion of each used in
commercial practice varies with different plants and localities, so that
it is not possible to assume a proportion representing average con-
ditions. For this reason the yields from different forms of wood of
the same species are presented separately. The corresponding yield
per given weight of wood, made up of any proportion of the various
forms, can readily be calculated. However, as a basis of comparison
between the species, the average yields from all heartwood runs (in-
cluding lumber) are taken arbitrarily as the species value. The mean
of the heartwood and slab-wood yields is also given wherever both
forms were distilled.

THE RETORT.

Figure 1 shows the construction of the retort in which the distilla-
tions were made. The retort proper A was surrounded by the oil
jacket B, which was filled with a high-flash-test cylinder oil. The
outlet pipe C connected the retort with an ordinary worm condenser
(not shown). The pyrometer tubes, 1, 2, 3,4, and 5, made it possible
to measure the temperature at various places within the retort. The
retort was mounted on an iron stand, was insulated on all sides, and
heated by a row of gas burners underneath. The flames from the
burners played chiefly up one side of the cylinder and induced a fairly
good circulation of the hot oil around the retort.

PREPARATION OF MATERIAL.

The forms of material used varied to some extent with different ~
species, but most of them consisted of round bolts. These were sawed
into slabs and heartwood in about the same proportion as would occur
in ordinary sawmill practice, and the percentage of bark on the slabs
was roughly determined. Sticks were prepared from 6 to 8 square
inches in cross section and a trifleless than 18 incheslong. Just before
each charge of wood was weighed, six 1-inch sections, each cut from
a different stick and in each case from a different part of the stick, |
were taken for moisture determinations. 5

In the comparative distillations on bark and sapwood the material
was taken from the same bolts. When limbs were used they weie

1 The term ‘‘ heartwood” as used in this paper appiies to the material left after the slabs have been removed
from a bolt or log. It was in all cases entirely free from bark, but small amounts of sapwood sometimes
remained. Lumber is considered as made from heartwood as thus-defined.

YIELDS FROM DISTILLATION OF CERTAIN HARDWOODS. 3

PETORT 'PROPER A
S
1

O/L BATH -&

s
:
Q
N
S

RETORT FROPEFR-A

Fig. 1.—Experimental retort.

4 BULLETIN 129, U. S. DEPARTMENT OF AGRICULTURE.

taken from the same trees as the body wood. In the case of factory
waste or lumber there was, of course, no record of the trees from which
the material came.

TEMPERATURES OF DISTILLATION.

Tt was found that the temperatures in pyromeier tubes 1, 2,3, and |
4, which are all near the surface of the retort, were always within
15° to 20° of each other, and usually within 10° during the last part
of the distillation. Tube 1 was the hottest and tube 5 the coolest.
Tt was, therefore, considered unnecessary to take temperature read-
ines in tubes 2, 3, and 4, and the records contain the readings from
tubes i and 5 only.

The maximum temperatures obtained in the various distillations
ranged from 327° C. to 415° C., and the maximum temperatures near
the surface and at the center of the retort often differed as much as
60° C. in the same distillation. These differences, however, did not
appreciably affect the yields of alcohol and acetic acid, since in some
instances higher temperatures gave higher yields, and in others lower.
Tt is also found that the charcoal from low-temperature distillations,
when redistilled in small samples at temperatures above 400° C.,
produced only small amounts of acetic acid (equivalent to an increase
of 2 per cent of the original yield of acid). It was considered, there-
fore, that the distillations were practically complete, as to alcohol
and acetic acid, provided all parts of the charge had been subjected
to a temperature of at least 320° C2

In most of the distillations, on account of the exothermic character
of the reaction, the temperature at the center of the retort finally
became higher than that at the surface. It was the heat developed
during the exothermic reaction which made it difficult to obtain the
same maximum temperatures in all distillations; after the reaction
was well started at the surface its progress toward the center was
spontaneous and the maximum temperature could not be fully
controlled.

The maximum temperature was usually kept below 260° C. until
the water was nearly all expelled from the wood and the temperature
at the center had risen to about 190° C., when it was allowed to rise
more rapidly. Only in this way could the temperatures at different
points in the retort be kept near one another. By this means also
the possible effect of variation in moisture content was minimized,
since the slow preliminary heating resulted in a partial drying of the
wood, and the different charges had therefore nearly the same mois-
ture content at the time the destructive distillation began. |

1 See Klason, von Heidenstam and Norlin, Arkiv for Kemi Min. och Geol. 1908, III, 9.

7

YIELDS FROM DISTILLATION OF CERTAIN HARDWOODS. 5)

-

TABLE 1.—Sample data sheet.

Shipment No. 197. Project No. 152.
Sample Nos. 21 and 22. Run No. 97.
January 14, 1913. Birch slab wood.
Actual weight of charge 69.86 pounds. 10 per cent to 14 per cent bark.
Dry weight of charge 63.10 pounds.
Temperature.
Total |
Time. ! distil- | Remarks.
Tube Tube laces) |
No. 1. No. 5. |
4 2 | '
January 13. oC. oC. | ASees |
LSI) Osage CESARE A Se eee el ted bia a ee 20M eae Seema | Retort charged; gas on one-half.
January 14. |
SWAY Alp Mile cc og oscocansacecencacsarscas 234 180 3,200 | Gas on full.
HU Os ite Gate So ae See C aes Sere see 280 220 4,2
ODO Awa eee s esse ona se eee ene 303 246 5, 700
HROG AMIN Shee ee cee ee oe Sl So Sos 312 263 6, 700
TTL TB ETT es agra ae See eaecean 317 278 7, 700
ROOT O RUINS es Seca 2aiSs arose Soh se 322 291 8, 700
WED aa Ween Ne Se eee Sarda she ce 329 305 9, 700
TUL SHB) Cele Se eek met le es rete rE Cl my 336 318 10,700 | Gas off.
oA Oeste ee eee BS See nS 342 325 11, 700
THE ear OS es ret Oe ee ee eee 342 351 12, 700
IMA TO S56 aad tedeboe siesta aeee eae 344 370 13, 200
A DOGIA INCE wae ae eon fee a Sais 2 a5 te a 341 378 13, 500
TIGRE CAS A O0 ae e ees eeeae eeee 339 a lara} ieee Maximum temperature.
TIQD TUBS oT ) 2 Seean a e ee aoep 337 BY |b sGseteaee
SOL Ae Mess es SE SS Ses sees oe Soe 282 284 14, 000
January 15.
UG YS TOTES tree eres eee eae nen eet eee Sees 50 14, 200

Total distillate=32.83 pounds.
COLLECTION AND ANALYSIS OF PRODUCTS.

A typical data sheet is shown in Table 1. The time and tempera-
tures were read as every liter or half liter of distillate was collected.
In a few distillations separate titrations for acetic acid were made
on the first several fractions of one-half liter or one liter each, but in
general all the distillate was mixed for analysis.1. The distillate was
allowed to settle for at least 24 hours. At the end of that time the tar
and pyroligneous acid were separated by decantation, and the vol-
ume and weight of each determined. The charcoal was allowed to
cool in the retort over night, and was weighed after separation from
the ‘‘tar coke.” Tar coke refers to the material occurring in the
retort that was clearly a residue from the distillation of tar. This
was weighed separately. The gas was computed by difference, and
no determination of its composition was made.

PYROLIGNEOUS ACID.

The pyroligneous acid was analyzed by the methods described by
Klar? for the determination of acetic acid, wood alcohol, and dis-

1 The acetic acid in that part of the distillate (consisting usually of water) which came over before true
destructive distillation began amounted to from 8 to 10 per cent of the total acetic acid; the alcohol in the
same part amounted to about 1 per cent of the total alcohol. The volatile acids obtained at temperatures
below the point at which the wood begins to distill destructively, say 280° C., must have an origin differ-
ent from that of the acid obtained during the destructive distillation. It is probably formed by action of
the water on the wood fiber at high temperatures similarly to the acid obtained by hydrolysis as reported
by Cross (Dissertation, GOttingen, 1910).

2 Technologie der Holzverkohlung, p. 337.

6 BULLETIN 129, U. S. DEPARTMENT OF AGRICULTURE.

solved tar. For the acetic-acid and dissolved-tar determinations
100 c. c. of pyroligneous acid were distilled at a maximum tempera-
ture of 140° C. until practically no further distillate appeared, when
50 c. c. of water were added and distilled off as before. The residue
in the flask was weighed and computed as dissolved tar, while for the
acetic-acid determination an aliquot part of the distillate was ti-
trated with normal scdium hydroxide solution, with phenolphtalein
as indicator.

The wood alcohol was determined by distilling 60 per cent from a
1-liter sample of the pyroligneous acid and adding an excess of sodium
hydroxide to the distillate, again distillmg 60 per cent, and after
again adding sodium hydroxide, making a third distillation of 60 per
cent. The final distillate was accurately weighed, and the specific
gravity determined by means of a Westphal balance at room tempera-
ture and corrected to 15° C. by using the tables of Dittmar and
Fawsitt.!. In correcting the specific gravity for temperature it is
necessary to consider both the concentration of alcohol and the range

of temperature.
TAR.

The amount of acetic acid in the settled tar was determined, after
Klar, by distilling 100 grams of the tar at 130° to 140° until the
watery distillate ceased, then passing steam through the residue until
no more acid was found in the distillate, the latter being then titrated,
as in the pyroligneous-acid analysis, and added to that found in the -
pyroligneous acid.

COMPUTATION OF RESULTS.

All the yields of products were first computed to a percentage of
the dry weight of the material distilled, since only on this basis are
the results directly comparable, the effect of varying percentages of
moisture in air-dry wood and of differences due to weight per unit
volume being eliminated. But because the unit of measurement for
wood is the cord, and the capacity of a plant is naturally expressed in
this unit, a comparison between the various species is made also on
the cord basis. A cord was assumed to contain 90 cubic feet of actual
wood, and its weight was derived from the average weight per cubic
foot of air-dry wood of different species as given by Snow.’

The actual volume of a cord differs, of course, for different forms
of material, due to variation in diameter and shape among the indi-
vidual pieces. Also, differences in density exist between wood from
different parts of the tree and between wood and bark; hence between
forms of material containing different proportions of wood and bark.
For these reasons it was impossible to estimate closely the weight
per cord of the several forms as compared with each other, and the

1 Trans. Roy. Soc. Edin., vol. 33. Quoted in Smithsonian Physical Tables.
2The Principal Species of Wood, by C. H. Snow.

YIELDS FROM DISTILLATION OF CERTAIN HARDWOODS. 7

weight is therefore assumed to be the same for all forms, and the
yields per cord computed on this basis.

For comparison with commercial conditions it is better also to
express the yields per cord in terms of commercial products, and so
they are computed as 82 per cent crude wood alcohol and 80 per cent
eray acetate of lime.

YIELDS ON PERCENTAGE WEIGHT BASIS.

ALCOHOL AND ACETIC ACID.
VARIATION AMONG SPECIES.

The average yields of total acetic acid and wood alcohol, expressed
in percentages of the oven-dry weight of the material distilled, are
shown in Table 2.

TABLE 2.— Yields of alcohol and acetic acid in percentages of oven-dry weight of material
distilled.

YIELD OF WOOD ALCOHOL (100 PER CENT).

| | | |
| | Mean | Ave |
| heart- | y0o-
Species. | Locality. | Heats eb eae moe ber Other forms.
| | slab | jeart-
| wood. | wood
| peach penser Pach el Duct. |e ck bei P.ct.
F r - > (Barkias 1. 25
IS OGG Heese so oe ern | $nidianass 32. == 1.95 iy 2.04 1. 87 1.99 |\Sapwood... 1.87
NO ek BE Se Pennsylvania...) 2.23 GA 1M ee cee ied iN Gee
Barehene eee Py | Wisconsin.....-.| 1.45] 1.55| 1.67| 1.50 1.54
Pieces Pennsylvania...| 1.62] 1.59 |..-.-... Tig oe
LU Oe ee eee ee | Wisconsin,:.....| 1.94 1.91 1.59 1.93 F/G) | eB ark 1.88
Pi eres 8 Ss | Pennsylvania.<.| 1.94 | 1.78). .-4..2: ites eee
ed fil os - se | Missouri. .....-- Kh. 1.76 PE ies, Boo Rese Ciel Gy aes
Ghesinutass2 5-22 Ss. 232 | New Jersey..... - 90 Sh |e Cad Jo ieee eee Limbs....- 96
HERO 528 4 25s 822: pelnplianary 232 37ap 5 2. Pee esas 2508" |5 os. 2. 08
Whe Ok 2s See ee eS Besos doe ee: 1.34 1.33 P5L 1.33 1.43
Cae Arkansas....-.-- |} 1.33 Pe AGUE S23 158!) a (eee
Mmupelge sees Sor ese Missouri.......- Peek 56 S60 ee noe bOT to they ee Limbs....1 1.64
YIELD OF ACETIC ACID (100 PER CENT)
! | | Bark 2.98
| rer | ~ » ro y GE Ke 2 5 '5= ~ Ke
Beech se tbe fe ene See eto Indiana........-| oO 56 6. 18 | oO 78 5. 87 5 6 ese 6. 67
Ge eee, ee | Pennsylvania...} 5.77 G220 ees Eig! ha) (ER eae at
Sot See eee | Wisconsin,......| 6.71] 6.88| 6.62| 6.80 | 6.68 |
19 Ye Ee SE ere cena | Pennsylvania...| 6.19 Oa esseses 6.157,|3-See |
Maples. 9 eo. eS | Wisconsin....... 5. 42 5.11 5. 58 5. 24 5.49 | Bark......- 3.15
Le a a a | Pennsylvania...; 5.66] 5.44 |..--.... DoD Anne a
TES gu a | Missouri.......- Dad Uys} ieee 5sAG ee Soe
GSE UNS a Se ee | New Jersey....- 250 Sh Pai ee ee Poa theca sel Limbs 6.42
Ebickonyae 5 esos - inGianae: ws ieee ee Eee ee Her AODs paeeee 5.05 |
LEGS Gor 3 Se al ae eae Gorey sors 3 | 4.97 4.77 | 4.84 4.87 4.78 |
La ee ae Arkansas. _-...- pe a asa Peres rhe ian fe Nees
Ju j,i Teo ee eee See PMEISSOGTS.55[ * 42407 eee ees ay Ce eR ee | Limbs 15.64

1 Heartwood not included in average, since only one distillation was made on this material.

The yields of alcohol and acetic acid vary a great deal among the
different species, more so for alcohol than for acetic acid. A given
species may rank high in its yield of alcohol but low in its yield of
acid. Thus chestnut, which gives the lowest yield of alcohol, is
among the highest in yield of acid; and hickory, which is among
the highest in alcohol yield, is among the lowest in acid yield.

8 BULLETIN 129, U. S. DEPARTMENT OF AGRICULTURE.

The average yield fromthe beech, birch, and maple wood from

Wisconsin and Indiana is somewhat higher for acid and considerably |

lower for alcohol than for the same species in Pennsylvania. ‘This
difference, when figured to commercial products—namely, 82 per
cent alcohol and 80 per cent acetate of lime—amounts to about 10
per cent of the alcohol and 14 per cent of the acetate of lime (ee
Table 4). The greatest differences are in the alcohol yield from

beech and in the acid yield from birch. In the case of maple, the

yields of both acid and aicohol are siightly higher from the Pennsyl-
vania than from the Wisconsin wood. In contrast to:thgse variances
in absolute yield, the relative yield of the three ces in either
product does not change with the locahty. The: order of yield for
alcohol is beech, maple, birch; for acid, birch, beech, maple. In the
case of oak, the largest difference lies in the acid yield, the material
from the more southern locahty giving the lower yield. The yield
of alcohol from wood cut in different States is very nearly the same,
but if the runs on lumber are included the average is shghtly higher
for material from the northern localities.

VARIATION DUE TO FORM OF MATERIAL.

Although slabs with much bark are usually considered very poor
material for distillation, the yields of alcohol and acetic acid from
slabs having as high as 13 to 25 per cent bark by volume are in most
cases only shghtly lower, and in some cases even higher, than from
heartwood. Distillation of beech bark showed that the higher yields
of acid from beech slabs were not due to the bark, but to the very
high yields of the sapwood (slabs without bark). These offset the
low bark yields sufficiently to account for the fact that slabs with
13 per cent bark yielded more acid than the heartwood without bark.
The same or higher yield of acid from the slabs of birch and tupelo
and from the limbs of chestnut and tupelo 1s probably due to the same
cause. The yields of alcohol from the sapwood of beech were prac-
tically the same as from the heartwood, and since the bark yields

considerably less alcohol, the slabs with 13 per cent bark yielded less"

than the heartwood. Maple bark yielded very nearly as much alcohol
as the heartwood, which accounts for the relatively high yields from
the slabs.

CHARCOAL, TAR, AND GAS.

The yields of charcoal, tar, and gas are not included in Table 2,
since they are influenced very much by the maximum temperatures of
distillation and therefore are not comparable to the same extent as
the alcohol and acetic-acid yields. Besides, these products are of
indefinite composition, which further prevents comparison. There
are some points of interest, however, in the relations between the yields
of these products, and in Table 3 the average yields of alcohol, tar,
and charcoal are shown, the species being arranged in order of the

YIELD£ FROM DISTILLATION OF CERTAIN HARDWOODS. 9

yields of alcohol.! The total tar yields follow almost the same order
as the alcohol yields. The yields of charcoal, on the other hand, tend
to follow the reverse order, but with more exceptions. The lowest
yield of charcoal and the highest yields of alcohol and of tar are
obtained from one species—hickory; while the highest yield of charcoal
and the lowest yields of alcohol and of tar are also obtained from one
species—chestnut.

TABLE 3.—Average yields of alcohol, total tar, and charcoal from the heartwood of various
species, in percentages of dry weight cf material distilled.
%

Species. Alcohol. Total tar.| Charcoal. || Species. Alcohol. | Total tar.| Charcoal.

- Per'cent, | Per cent. | Per cent. Per cent. | Per cent. | Per cent.
HUCKOKY ees seen 2.08 13.0 Bed My abibjoelOe oo Soodasooee 1.56 10.6 | 44.1
Dpecliqeee ste) 3 2.08 | 9.4 A190} EBireheeesel alee 1.53 12.0 | 40.6
Ma ploeaen se jm see 1..94 | 12.8 40263" @ alkenes prcree eas 1,34 7.8 ADT.
IRvedvoumiese 4. 25585 1.76 sll, 7 382 On|] Chest tees a . 90 4.6 47.6

YIELDS PER CORD.
ALCOHOL AND ACETATE.

COMPARISON OF YIELDS.

Table 4 shows the same results as Table 2, but expressed in different
units—the raw material in terms of gallons of 82 per cent wood alcohol
and pounds of 80 per cent acetate of lime.

The yields from the various species on a cord basis are quite different
from the yields on a unit weight basis; the heavier woods, such as
hickory and oak, are advanced in relative position, and the lghter
woods, such as chestnut and red gum, are reduced.

The average yield of alcohol from Indiana beech and Wisconsin
birch and maple is 10.9 gallons per cord; the yield from these species
from Pennsylvania is 11.51 gallons per cord. These figures represent
the average yields obtained at commercial plants in these localities.
The average yield of acetate of lime from these two groups of woods,
319 pounds and 315 pounds per cord, respectively, is about 50 per
cent higher than the average commercial yields. The yield from
white oak from Arkansas of 9.2 gallons alcohol is very close to that
being obtained in one commercial plant, and the acetate yield of 262
pounds per cord is, as in the case of the standard species, about 50
per cent higher than the commercial yield. The only ways in which
the experimental distillations differed from commercial! conditions
were the low maximum temperatures and the short distance from the
center of the charge to the heated surface of the retort. It is possible
that these two conditions, resulting in a slow and well-controlled
distillation, are sufficient to account for the higher yields.

1 These averages do not include the yields from ‘‘lumber,’’ since this material was usually very dry
resulting in maximum temperatures much higher than the normal, giving yields of tar and charcoal not
comparable with the rest of the runs.

2 A corresponding difference between the Lake States and the Eastern States is also obtained commer-
cially in the acetate yields, but this difference is not shown in the laboratory yields. It must be remem-
bered, however, that these figures represent the average from equal proportions of the three standard species,
while in actual practice one species may predominate.

10 BULLETIN 129, U. S. DEPARTMENT OF AGRICULTURE.

In Table 5 are given the relative yields from the different forms
and species, taking the average of the heartwood and lumber runs

io

a a

VLA BEECH-IND = 94.0YWiYYYYYVLLLLLLL
WHS:

WLLLOKK - - IND.— 96.6 LAL LLL

[ea a
LLL BELA PENNSS2 WLLL LLL

ee Ss
| oe Oe a

WALLA BIRCH - PENN:100.0 YYW MMU

| Bars e
lc LLL

VL BIRCH= WS = 108.5 LLY MMMM

PPT tr

VZZZZCHESTNUT~ — 59.6 WYLIZLLLLA, |

ETIBSAN RTS WV.) ©) 0 ee ee eee

ae ee

WL RED. GUM = —_ 77. 6§ YY 3

LMA AUPELO =~ = 816 YYU“U&#//, com LEE,

|

[oes
VILL MAPLE-WiS ~ 85.1 WW LALLELLELEEEEEEELEEEELELLEEE.
WWE EU

aeucseueceueseessan

VL SIRO PERN= SES ae
SIE |

eR

VELL EEECR-PENN=IOS1 WLLL LLL
Bs A a te

AZZ BIRCH-WIS— | 3UYVLLL

CLAZCHESINU ~~ 72 BYLLY LVL
YUM ae YY

“LIMBS>

O lO 205 30-40% 30 60. 76> 86> * 90-4100" HOS 128
: PERCENTAGE

Fig. 2.—Relative yields of acetate oflime per cord. (Average yield from heartwood
and lumber of beech, birch, and maple from Wisconsin=100 per cent.)

on beech, birch, and maple from Wisconsin as the standard (100 per
cent). The same values are shown graphically in figures 2 and 3 for
acetate and alcohol, respectively.

YIELDS FROM DISTILLATION OF CERTAIN HARDWOODS. ial

= oar ie ee
canna EEE

ae aa a ue 2 ZIMA TATA ara

panne} = se LILA

ZZOAK— ARK— 64.5UW//7/7 ee

Z2OAK — IND. = 84.5 (WILLA LLL

ZA RED GUM —— 86 2V/YYULLA LLL ALLL LLL mt

HEARTWOOD

UA BEECH -IN D108 20/{0W/W LLL ZH TALUTLTAT WY,
WZAMAPLE-WIS -108 20//{W/WY YALL ALLL ») eee LLL
Mee ne Ws Meme
Tor ——— Eee -—— WUUMMUMIU“[“§LUA{WMU_“4£t#d zs

CAE OE ence eect erat

WatY.

ee ey, es Bees
CZARED GUM—- 84.8 (W/V
meee OO AOA Ws

VA BEECH-PENNA'5. OLY ITI VET MEET meen ,

aa eae
pene CT
mom | | tT |

10 20 50° ~=2—660 ai 120 130 140
PERC ae GE

<LIMBS>

Fig. 3.—Relative yields of wood alcohol per cord of wood. (Average yield from heartwood and lum-
ber of beech, birch, and maplefrom Wisconsin=100 per cent.)

12

BULLETIN 129, U. S. DEPARTMENT OF AGRICULTURE.

TABLE 4.— Yields of commercial alcohol and acetate from various species per cord of wood.
YIELD OF WOOD ALCOHOL (82 PER CENT).

l + | l
| | Mean | Aver- |
| heart- | age |
Species. Locality. | Heart ash us | ood eee Other forms.
| slab | heart-
| | wood. | wood. |
! |
| '
| Gals. | Gals. | Gals. | Gais. | Gals. Gals.
IB CEG Dae ae aes ne See indianaase aes 11.8 10.9 12.2 11.4 12.05 | Sapwood..- 11.9
Ose AR A ee Pennsylvania 1355 12264 eo eee 13 55a eee |
ITCHY ete ae ee eee Wisconsin.....-- leetsas 8.9 9.6 8.6 | 8.9
Repoee, See eee Vale Regs Oe Pennsylvania...| 9.3 CV a 9:2: 18) Sam |
(Maple seene eee se eee Wisconsin.......| 11.8 11.6 9. 87 11.7 10.9 |
Onn ee ee ee Pennsylvania...) 11.85 Sel esueses= abet Ie aoa eae oes |
Red cums 4s See ee IMASSOQUTIS=e == == 9.4 OR 2 AP eae sm Yee See eaae
Ghestnut+ see lee. New Jersey..-... 3.7 SaOdlee wees Babes een ieee Limbs: 2-5 3.9
LICK OnYisst eee ee imndiannee ss | Sa eas eee ace 1553 ou | eae eee lzseae ee
Wilt GrOniksesw peste e eee ate aes 8 isaeee te Gos 9.2 9.2) 10.4 9.2 9.9
1D) ee ee ee Che Se Arkamnsas.-....... } 9.2 i) ol Dm ome 95G55) See
Wupelos 22645. = oss 2228 eIVETSS OUI oan 18.75 ORAS eee 9.1 [cece iimbssseee 9.2
|
1 Single unchecked determination.
YIELD OF ACETATE OF LIME (80 PER CENT).
|
| | Mean | Aver- | Weight
| = Pieossliee heart- | age | per cord
; Ar eart-; Sla um- | wood | lumber} 5
Species. Locality. wood. ; wood.| ber. | and | and Other forms. | per cent
| slab | heart- moist-
| wood. | wood. | ure).
| | | | |
| Lbs. | Lbs. | Lbs. | Lbs. | Lbs. | Lbs. | Lbs.
Bescha ak S254: Indiana=.s.- 301 | 339 313 318 307 | Sapwood... 361 3, 783
Oe ee Pennsylvania. ..| 313 | BEY lide eC 325 ae eal ee eee 3, 785
Birchee.*: See Wisconsin.......) 346 355 341 350 S48) | ~ 5 J 2 ae 3, 600
Gunga ae Pennsylvania. -.| 319 S14 316 jess ae 2 eee ee 3,600
Maple sa. 2.825: Wisconsin....__.} 301 284 310 293 BOD N Reee se ee 3, 875
Os ee Pennsylvania. -.| 314 | 3023 eases 308: | Se See |S Se A aires 3, 875
Red gum.......| Missouri.......- 269 DAT Gree 258-2. Be Alea oa eee 3, 300
Chestnut.......| New Jersey..--.- 198 190 3|b eee 104% | eee ee Limbs..... 232 2,520
MACKOGY222- soe a ligVo b trots pee peepee |S el |e ee BBY) ute ier 5 P| able OO per 8 4,590
White oak..... ese do tyes ink 2 | 308 295 300 301 3053) .6:5 5) eee 4,320
ID Xo) ee Se Arkansas.......- 262 269 is| etme 265.) 522s sla a ee eee 4,320
Tupelo: 2h k ie Missouri |e 26 260 a osa se Fee a Se oe Limbs. ...- 283 3,510

1 The weights per cord are derived as explained on p. 6.

TaBLE 5.—Relative yields of commercial alcohol and acetate per cord of wood of various
species. :

[Average yields 2? from heartwood and lumber of beech, birch, and maple from Wisconsin equals 100 per
cent.] ;

Yield of acetate of lime

Yield of wood alcohol

(80 per cent). (82 per cent).
Species. Locality.
5 Heart-| Slab | Heart-| Slab
aaa | anEadL Other forms. Sal aa Other forms.
Gals. Gals. Gals. | Gals. | Gals. Gals.
Beecher sees indianas ees 94.6 | 105.0] Sapwood. 113.1 | i08.2} 100.0 | Sapwood 109.1
DOE Soe eiad Bennsylvania.2:| 98:2) |e 1050g eee ee ee ee | 124.0] 115.6
Birches ye Aenean Wisconsin.....- 108.5 SSL SA oes ey cape See emcee LOL2y | BaOLao
IDOLS ay Pennsylvania...| 100.0 62 Fea 6 es Sap et ne 85. 4 83. 5
Maples tane ae! Wisconsin....... 94.7 SOI | ee Tne ee a 108.2 | 106.5
DOE Pennsylvania...}| 98.5 Or aa Eons Sere Siena 108.8 98. 2
Red (gnnts See Missouri s (3-322. 84.4 IAD a| Beten ea Ae Sete 86. 2 84.5 ;
Chestitaseanen ss New Jersey... -- 62.1 59.6 | Limbs... 72.8 33.9 33.0 | Limbs.. 33.8
CkKOnyeee = eee Indiana eos. ae 0 Hs Bl Pere et oy des rea MONG ess- 0. Se
Wihliteloakaes nee eee (6 foyer 96. 6 92 balls Seer oe aa Fe 84.5 84.5
DOD aiame neh Arkansas.......- 82. 2 toy Ae We Ne Eat Cn ge 84.5 92.7 ;
upelossee as eee |Miissourr <= ee e=— | 70.9 | 81.6 | Limbs... 88.8 | 80.3 95.5 | Limbs.. 84.4
pee) ll ee A eT AL ce

1 The weights per cord are derived as explained on p. 6.
2 Acetate of lime, 80 per cent, 319 pounds; alcohol, 82 per cent, 10.9 gallons.

-

«ee

YIELDS FROM DISTILLATION OF CERTAIN HARDWOODS. 1133

~

COMPARISON OF VALUES.

The combined value of commercial alcohol and acetate of lime
from the various forms of material per cord of wood of the various
species is given in Table 6, which is computed from the yields given
in Table 4. These values are according to the prevailing prices for
LOtI—t3.

In judging the value of the different forms and species for dis-
tillation, the yields under commercial conditions must be -consid-
ered, and therefore the value of the acetate per cord of wood of
different species 1s computed on a basis of two-thirds of the yields
shown. The value of the alcohol is based on the experimental
yields, since these are at most only slightly higher than average
commercial yields. Tar and gas are not included in the computa-
tion of the value of products, because they are relatively unimpor-
tant and are commonly used as fuel at the plant. Charcoal is one
of the valuable commercial products, but is not included because
there are no definite data from which the values might be computed.
The charcoal produced by the experimental method has not been
subjected to temperatures as high as in commercial practice, and
therefore contains more volatile matter. Although the relation be-
tween the yields obtained from different species in the experiments
might be the same as between those obtained by commercial meth-
ods, there is no information on the quality of the charcoal from
different species. Also, charcoal is usually sold by volume, and since
no data are available on the weight per bushel for that produced
from different species, the yields can not be computed to commer-
cial units.

TaBLeE 6.— Values of commercial alcohol and acetate per cord of wood of various species."

Values of wood alcohol and acetate of lime during period 1911-13.?
Mean Aver- Ww sieht
Species. Locality. ze clean | Bee : ue Conane
| Heart-| Sla um- | woo umber y
wood. | wood. ber. | and Other forms. and (lo PF B
| | slab heart- | mois:
| wood wood ture)
| Pounds.
Beeches. 6 <: in cian ae | $8.08 $8. 41 $8. 38 $8. 26 | Sapwood, $9.10.-} $8. 23 3, (80
DOME Ss ses $32 Pennsylvania. .- 8. 72 Sr SORE Jaa ee SRS PERE hs se AR Eo Saye 3, 785
IS TEC Pape a ce Wisconsin.....-- 7.92 8. 22 8.17 oO Seana ee Byes ee 8. 04 3, 600
AD) OR ee pe Pennsylvania... 7.73 TDF es See os TEAK s| nes Pek ERR ER BAe Ce Os i a 3, 600
SIGH Oe eaeace epee Wisconsin.._.... 8. 08 7. 74 Wafe (eS) ae is Aer eee ee eee 7.90 3, 875
DOM Is Pennsylvania. .- 8. 31 13 80)\| teers: SS (OLS) Nata te CR a ope cae |S 3, 875
Red gum......-.- Missounls 2 522252 6. 92 GNo On eee (G7 hc enamine ces 3, 300
Chestnuts: .: 2.. =: New Jersey - --.. 4, 28 yaa BS oe Sete AD TO Mims, $4:892 5S. ae 2,520
PNCKOLY zen. oe ernie as py canes eee ee ha ORSIU lh sete oder ae Some ees Eee nee 9. 51 4,590
(0) Nes rcp Pol cae 2 COs eee 6 7.30 7.70 Ells | antes tes he OR 7. 61 4, 320
Dosee ose Arkansas.....-.. OS TOd GRO Sd eset ae - GSO DIS at MiMi 2 TEE eee 4,320
Mupelosss.2eeec: Missouri.........| 46.04 7803" |e aaae 6959), | Mui sys 70 secs| a sonee 3,510
|

1 The market price of cruae alcohol is fairly stable, but acetate of lime fluctuates considerably from
time to time. For this reason the relative value of the different species, from the standpoint of value of
products, may vary from the calculations indicated.

2 The weights per cord are derived as explained on p. —. :

3 At 26 cents per gallon for alcohol and $2.50 per hundredweight for acetate of ime. The acetate 1s com-
puted from two-thirds the yields given in Table 4.

4 One determination only.

14 BULLETIN 129, U. S. DEPARTMENT OF AGRICULTURE.

TABLE 7.—Relative values of commercial alcohol and acetate per cord of wood of various
species.

[Average value of yields from heartwood and lumber of beech, birch, and maple from Wisconsin ($8.06)
equals 100 per cent. ]

Heart- we
“ F Heart- wood EEE
Species. Locality. Saal Slabs. Saal wood j|Sapwood.|} Limbs.
: lumber and
: slabs.
|
Per cent. | Per cent. | Per cent. | Per cent. | Per cent. | Per cent.
IBeCChS Sera Te ee Indignal sense 100.2 104.2 102.1 102.5 £130 bes ee
DON aan agen Wee Pennsylvania. ..-. 108.1 HOS 2d ee ee OQ 32) |. ce ee | ae eee
BITCHES Mee oe Res eae WASCONnSINe =a a= 98.4 102.0 97.7 LOO Leek eS ae| eee
WD Oeet eae ee Pennsylvania. ._... 96.0 Db e Oh se eecees 958) | keel ee
Maple ssc ect air Wisconsin..-.....- 100.2 96.0 95.8 98544) 5 Sy S585,57 | ees
TD XO aes ails oes nee Pennsylvania... .- 103.0 CBU eae sets LOS OMS se eae eee
IRGC ouiniees ee MSSOUTIS oa 86.0 SON alas 83.3) | 3) Sse | See ee
Chestnittaiee soe eee New Jersey...-..-- 53.2 SBOE ees Se See O22 ae eee 60.7
LH CKOnY AE ee eee HCG WEEN BY ih oe Set SE aos | ea ey 118500 5252-225. | ose ace ee eee eee
Wiltteoaks eee ee gee: 6 KO Ses ee 93.3 90.7 94.5 92.0: 3523 ee ee ee
1D) OMe eee el AT KANSAS sane ne 83.9 S80 essere ace 85. 941-5. doses | ae ee
Tupelowen tee Ae e =e Massouris=see ==. - 75.0 ST i2h| ssa SI. Soa see 88.1
|

1 The weights per cord are derived as explained on p. 6.

Assuming that the value of the charcoal and the cost of plant
operation per cord of wood is the same for all species, the differences
in the value of the alcohol and acetate produced by the various woods
represent the differences in the value of these woods for distillation
purposes. The average value of the alcohol and acetate yields
from Indiana beech and Wisconsin birch and maple heartwood is
$8.06 per cord. The values of these products from the heartwood
of chestnut, red gum, tupelo (slabs), and southern and northern oak,
are less than this amount by $3.78, $1.14, $1.03, $1.30, and $0.54,
respectively; from hickory (factory waste) the products are $1.55
greater in value. The average price paid is only about $3.50 per cord,
and consequently the use of chestnut for this purpose is out of the
question. Oak, tupelo, and red gum, under favorable conditions
of supply and cost, might be used profitably, while hickory should
command a very good price for this purpose. Since these deductions
are based on the value of the chemical products they apply less
strongly in case of plants making only a partial recovery of these
products. :

The value of alcohol and acetate from the different forms and
species as given in Table 6 are compared in Table 7 by means of a
standard value. This value is $8.06, being the average value of
beech (from Indiana), birch, and maple heartwood (from Wisconsin).
This standard is taken as 100 per cent and the other values are ranked
accordingly.

1 The assumption in regard to the cost of operation will undoubtedly hold so far as the destructive
distillation of the wood is concerned. However, the cost of the refining operations is approximately
proportionate to the amount of crude pyroligneous acid produced; although this is variable, it bears some
relation to the yield of refined products. The large amount of crude pyroligneous acid per cord of hickory
would tend to increase the refining cost per cord of wood; likewise the low yields of crude pyroligneous
acid from chestnut, tupelo, and red gum would tend to lower the cost of these woods. Therefore, the
assumption made is not entirely correct, but the differences are not great enough to affect seriously the
conclusions.

YIELDS FROM DISTILLATION OF CERTAIN HARDWOODS. 15

The value of the two products (alcohol and acetate) from hickory
is 18 per cent greater than the standard chosen for the comparison.
Of the other species, oak from Indiana is the only one which falls
above 90 per cent; with all the others, except chestnut, the average
yield from heartwood and slab wood is above 80 per cent.

Of equal interest to these relative values based upon species are
the relative values of the different forms of wood from the same
species. These relations are shown in Table 8, in which the value
of heartwood in each case is taken as 100 per cent. A number of
species show a higher value for slabs than for heartwood. The slabs
of Indiana beech, Wisconsin birch, Pennsylvania beech, and Arkansas
oak are from 2 to 5 per cent higher that the heartwood, while the
limbs of the two species tested, chestnut and tupelo, are about 15
per cent higher than heartwood. These results are based upon
equal weights of the several forms of material compared.

TABLE 8.—Relative values of commercial alcohol and acetate from equal weights of various
forms of material.

[Heartwood=100 per cent.]

Species. Locality. Heartwood.| Slab wood.| Sapwood. | Limbs.

i Per cent. Per cent. Per cent. | Per cent.

COC eee ae ete an Inovshehoe) a coshoudeeseoouae 1 104.0 DAD eS Ae es
ID) Opes ee sees cries Pennsylvania..........--- 100 O20 eee taser lar tar eae
IBSITG aan eet de ass WWASCOnSIM SS janet 100 OR eo i Mes end ais eo cl ot
ADYONSSS, Bes eee ees oe eed Pennsylvania...........-- 100 RD | ae ee eaae Ae age
Maples nisacmatee eet. Se WiASCcONSIN SoS seeeece ese 100 QB Gi |e sen coe eee tern eee
IDO socéesueecarauese ...-| Pennsylvania. ...........- 100 QS O Ih eee eae eae ap ee
Riedioum 2.2 ssi2 5255s ese IMUSSOUTIAS seen ma cee 100 Danie ecard ek tcealpe Waa aenepers
Chestmutie sree eae ee New Jersey.....---------- 100 OGS OR ese tae 114.2
HN CKOT V5 eos oan eins lunohieiags 3 tedoadescoeease TOO ieee is A axhlle Dis el Ne ee as nee
Wihtteoak- masts 256 ere oe Ss)es ae GOR eee eee eee 100 O)ife OAs \aubeereie ree ee altar os edd:
1D%0) She haere eee eae eee ATKANISASS Ales ye ney ees 100 LOAN STB Seo Sg Cun hea ene ete
iapelosecetee oes oo eee IMASSO UTI es eer 100 GIO eee ees 117.5

PYROLIGNEOUS ACID, TAR, AND CHARCOAL.

The average yields of pyroligneous acid, tar, and charcoal from
the various forms of material, expressed in pounds per cord for each
species, are givenin Table 9. Although the yields of these products,
especially of the last two, are directly affected by the maximum tem-
peratures of distillation, and are therefore not as accurate as the
alcohol and acetate yields, some conclusions of interest can be drawn
from them. The yields of pyroligneous acid are of interest mainly
in connection with the cost of refining the products from a cord of
wood. (See footnote on p. 14.)

The average commercial yield of charcoal from a cord of beech,
birch, and maple is about 50 bushels or (at 20 pounds, the usual
weight per bushel) 1,000 pounds; the average yield from the heart-
wood of the three species by the experimental method is 1,378 pounds
per cord. This large difference is probably due chiefly to the low
‘maximum temperatures of distillation, resulting in a charcoal with
a high amount of volatile matter. Charcoal of this composition
would probably be satisfactory as a fuel for domestic use, but where

16 BULLETIN 129, U. S. DEPARTMENT OF AGRICULTURE.

high carbon content or high crushing strength is required it might
not be suitable. | :

The yields of tar are also somewhat. higher than those usually
obtained in practice, and this can not be explained entirely by the
low maximum temperature of distillation, since further distillation
of the charcoal at higher temperatures gave increased production of
tar. (See p. 4.) It is probable, however, that under the experi-
mental conditions of distillation there was less tar decomposed into
gas and coke than under commercial conditions where part of the
tar would be subjected to considerably higher temperatures after
formation.

TABLE 9.—Average yields per cord c rolignecus acid, charcoal, and tar from various
By a 2 ?
species.

PYROLIGNEOUS ACID (MINUS MOISTURE).
Mean | Aver-
ares heart- : age
a aes eart- a um- | wood |lumber :
Species. Locality. ma | SGsE. nos na ene Other forms.
slab | heart-
wood. | wood.
Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. -
Recehees eee Endianae +22 cies 1,062} 1,165! 1,119] 1,113] 1,085 | Sapwood.. 1,149
IDO Sipe tane ae Pennsylvaniae <a) e080. eter osa leer nT), | eee
IBTCCI De = Sk eee ee Wisconsin.2---2=- | 1152 1,159 1, 220 1, 156 1, 167
DOP ern ton Me a Pennsylvania... -. VRE) es EBay eee 102A eee ee
Maples heen a ee Wisconsin......... 11205)" 1061 | 15207 1145 4 857
ND) ORs ES Seer Pennsylvania..... 1a Z a1) eke GA eee Se ole lA The vere
Evodeatinn e6: et sGx eta 6 MISSOURI See 2 5 4|g 11098 Cy dale el sae POOF. ete of
Chestntite eee ee | New Jersey. .-.---- 790 644 obese ses Cla eee Em pSs eee
ERICK ORY eae one ee | heYsh Ghia SNe Sx Seal ga ees ale ne Ty AQ5 ene el 2 be4S5
White Oana st Sawn e mites donseen 17230 | et 1701) 7s le eG
ID) OFS ieee eee eae IUAREHICES So secanaal UN VIIA ee sae (B13 ees ae
Rupelosen nee fo Missouri. (2... 22. POSE fon 12065) eee eee Te Til eremeeclee Limbs. ... 1,049
CHARCOAL. s
ISYEEG)S Se SeH ae eee ein Giana: yee ae 1,417 297 1,385 1 Bey: 1,403 | Sapwood.. 1,470
DOT e ee Sie 2 | Pennsylvania. ..-- sa0Ft wlesson lessees 13599)
ISTixdik. ee eee ea | Wisconsin.........| 1,315 | 1,284 | 1,286 | 1,300} 1,303
Doses ee ee se 7S | Pennsylvania..... 1 28") 00 pe ee 1*965 Loe
Map leriae iinet oe ee rs le WISCONSIN ee ISS4s LoL on eles 485 eels 4 4u eta O
DD) Oe ee hoe SEE AEN | Pennsylvania. .... TSW | IL AGS, leew cance EAST ae ee oe
Redeem ese ae | IMASSOUTIS: ee | pal OO Simla G0 n| seen ILA) el eee = See
Chesiiitpee= eee ee New Jersey. ...--- WAGE |) TWA enna ese E02 Sees Limbs..-- 1, 061
IE CK OR Vee a tae eee Fel boku Ghovs as Sea era rene eo (Pere oo MOO tee wees se 1, 500
Wihiteoalke 926: sehen ts. tans donee. va 1,858 | 1,892| 1,625| 1,875 | 1,715
Ope ae aegis 5 es TACO. TIGA Sel eee ts 1, 580 IO leseocaee TG 54s 2 aes ‘ :
IUIpelonaaek ve Seis a) | Miissotinitea 2 212s) S74 cou e405 <p eee £402 |p ee Limbs-..-. 1,320
TO ATE AGRS
b
Cache catn see eae arama eae 319 349 342 332 329 | Sapwood.. 250
WOss et osc Sees | Pennsylvania... 299 BO) || sae 329 jee
JEU TRela ie ee en ee REC | Wisconsin........- 325 285 338 307 | 330
DOs CORRE See | Pennsylvania. ...- 426 Sa 7 |). epee GSS et
Maple. face ae eee | Wisconsin,.......- 418 310 500 450 360
IDO ee hi eee ee | Pennsylvania... .. 422 AlGe|s225 a= se 48 )|2 fet eeee
vedere ein wea sae lSMNSSOUrIL ss. 25520 336 215 | eee D1G Ae ee a
Chestninteseee os fos ese | New Jersey. .-..-- 102 80) 552s Qi eee ren es Limbs. .2 2) 993
IEMCKORy ee ee ee indiana eee | ai Jay. pe Pan aoe SION Ee ee 519
Wihitteioalea2 2. a ates peasae COs ee eee: 237 173 331 203 285
1D) Oo ee See PAE RAN SAGs oe 349 SRF eee SBieleaeene ce
bubelosses ees eee | Massounies2 a bs f-2¢ 348 SHO |e caeev ek 3645 | Se Limbs.-.. 447
| I &

1 The weights per cord were derived as explained on Dp. 6.

WASHINGTON : GOVERNMENT PRINTING OFFICE: 1914