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Full text of "Nonwood Plant Fiber Paper Production"

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Lyrasis IVIembers and Sloan Foundation 



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Nonwood Plant Fiber Paper Production 



Gregory W. Koehlert 
June, 1996 



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This study of non-wood plant fiber paper production was conducted through the 
pubhshed papers of the world's plant liber paper experts. These were collected and 
published by the TAPPI press, and have been regarded since 1970 'I'his industry is one 
which is in a continual state of development, so the majority of the resources used in the 
paper are current. Nevertheless, I read most all of the older papers to gain perspective on 
the growth and development of plant fibered paper production over it's modern history. 

The results of the work show that when not quantifying environmental damage, 
cost for this paper is higher, albeit not incredibly higher, and that all grades of paper can 
be produced using varieties of plant fibers, residual and specialty. The importance of this 
paper to the person not involved in the paper industry is it clears the myths surrounding 
plant fibered paper and demonstrates it's capabilities. As far as 1 am concerned, the paper 
represents a part of my work- the assessment and compilation of material modern and 
relevant to this paper's aim in describing an aspect of the plant fiber paper industry. The 
work and study unseen in this paper is equally extensive, as there are voluminous amounts 
of published literature on this topic, collected by paper industry groups and world paper 
industry professionals. 



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Nonwood Plant Fiber Paper Production 

Introduction 

Demand for paper in developed and developing countries is increasing steadily, and much of 
this is met by North America and it's forests. Currently the United States exports, as raw material or 
finished products, 32% of the wood cut each year (Springer, p.51 ). The other great supplier of vk'ood 
products is South America, where large tracts of incredibly valuable biologically diverse forests have 
been logged for wood fiber, and are being replanted with single species most suitable for paper and 
lumber production. 

With demand for paper growing and the biologically diverse forest base shrinking, we are in 
an ecological dilemma which has a three part solution. The first part is to decrease paper 
consumption by reducing the amount paper we use, and the second part is to recycle what were once 
considered disposable paper products. These measures would decrease the consumption of paper in 
the United States, where per capita we consume 320 kg. per year. For comparison- the next greatest 
consumer of paper is Japan, using 225 kg. per person per year, followed by Canada where 2 1 5 kg. 
per person are consumed, and Great Britain where only 175 kg. per person are consumed Mexicans 
are only averaging 40 kg per person and the Chinese 20 kg.. Compared to the developed countries, 
our level of consumption seems excessive, especially when the cost of our consumption is our 
landscape and forest environment. 

The third means to meet the demand for paper, while reducing the burden we put on the forest, is 
to replace the wood fiber currently used with any of the multiple fibrous plants which are suitable for 
growth throughout the continental United States. These plants can be used to produce all grades of 
paper. 



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In my research I examined the published technical h'terature concerning the developing use 
of fibrous plants for papcrmaking; the information comes from papermaking scholars living 
throughout the world, and particularly often living in developing countries. This paper describes the 
most important of these plants in respect to American papermaking. Amongst the individual rep(jrts 
concerning each plant is information on the plant itself, it's United States and world availability, 
information on the fiber characteristics, information on the collection and storage of the raw plant 
material, and whenever possible, cost comparative infonnation for each of the plant fibers discussed. 



Nonwood Plant Fibers 

Nonwood plant fibers provide a raw material alternative to the use of both wood fiber ^id 
recycled paper fiber and are potentially available in great quantities. In America the potential supply 
I of raw material for nonwood plant fiber paper production is enomious but it is underutilized by the 

American paper industry. Currently, 0.3% of the pulp in America is nonwood pulp. 

From the three fibrous plants examined in this paper, bagasse and wheat straw have a 
potential availability of 80,400,000 bone dry metric tons (BDMT) (Atchison, p. 127). The 
availability of kenaf, the other important nonwood plant fiber, is only limited by how much we 
choose to grow, and is clearly viable. This conclusion is supported by the USDA, who have chosen 
kenaf as the most important agricultural crop for paper production. The USDA has also consistently 
fimded research on paper production and other uses of kenaf The availability of just these three 
nonwood plant fibers far exceeds the 0.3% which is currently utilized. In the face of deforestation, 
shrinking fiber supply, and increasing demand for wood products, these need to be developed and 
used by US manufacturers. There are other nonwoods which are in considerable quantity in America 
but have little available research on suitable methods of emplo\ang them. They are not a subject of 



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this paper, but their availability further supports the position ofnon-wcxKl plant llbcr industrial 
development. 

Types of Nonwoods 

There are two types of nonwood plant fibers- agricultural residues and agricultural fibers. 
Agricultural residues are by-products of crops already in production, and have land which is 
allocated to that task. Bagasse from sugar cane and straw from the wheat plant are the two most 
viable of the residual fibers available for the production of paper in the United States. The 
agricultural fibers, on the other hand, are specifically raised for their fiber value. For their production 
land must be diverted from it's present use. In the United States kenaf is the most important of these. 



Rational for Development 

The incentive for the United States to develop the nonwood paper industry is much different 
from the situations under which other nations have developed their nonwood based paper industries. 
Nonwoods have traditionally been the native fiber source of countries which have either been 
deforested, or have never held large forests. The world's production leaders in nonwood plant fiber 
are China and India. China supports 86.9% of ifs paper demand by producing 15,246,000 metric 
tons of nonwood paper yearly. India supports 55.5% of its paper demand with 1,307,000 metnc tons 
of nonwood paper per year. Thailand and Pakistan are using 100% nonwood plant fiber for paper 
production and Greece 85.7%, but consume considerably smaller quantities of paper than China and 
India, so it is conceivable that they can rely so heavily on plant fibers (Atchison, p. 128). 



Most countries currently using nonwood plant fibers are poorer than the United States, and 
have lacked the technical ability to increase production or the capital to purchase new technology. 
\ Therefore nonwood paper production has not been developed and refined as quickly and to the 



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degree to which paper production from wood liber has in the developed and forest rich world Too 
often nonwood plant fiber paper producers attempted to use traditional wood pulpmg techniques and 
their results were unsuccessful. For this reason forest rich countries like the United States abandoned 
early efforts to utilize these fibers. 

More recently, and especially in the last 10 to 20 years, monumental gains in plant fiber 
paper production have been made. Processes and equipment have been specialized for the 
production of paper from nonwood plant fibers and process efficiency has increased dramatically. 
Nonwood plant fibers are now suitable for commercial production in the United States. 

Fortunately for the US, nonwood pulping research and technology has benefitted from the 
investment of the less forest rich and less developed world. The impediments which made this type 
of paper production technically and economically non-viable in the U.S. economy are being 
overcome by these new processes. With new technology and information, and the greatest 
availability of agricultural fiber in the world, the United States is in an enviable position to take 
advantage of the benefits nonwood plant fibers offer to the ecology of this nation. 

Bagasse 

Bagasse, the fiber relieved from the sugar stalk, has received the most attention of the nonwood 
fibers primarily because it is harvested and collected for use by the sugar industry, but also because it 
is a very good paper fiber. Procuring the raw material for paper production is simplified in 
comparison to other nonwood plant fibers where collection is not yet organized. For this reason 
bagasse usage has increased more since 1959 than any other fibrous raw material, and the amount of 
pulp produced irom bagasse in the last ten years has nearly doubled (Atchison, PR#18, p. 1 1). 



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Availability 

Worldwide, there are 102 million bone dry metric tons (fiDMT) of bagasse available; 
4,400,000 BDMT of which are produced in the United States (Atchison). From the 4,400,000 
BDMT, 50 - 65% converts to pulp aller the poor quality fiber is removed, so that the United States 
has a usable fiber supply of 2,200,000 to 2,860,000 bone dry metric tons which are available in 
Texas, Florida, and Louisiana and are convertible to paper if a supplementary fuel source is available 
to the sugar mills who produce and ovsti the bagasse. 

Bagasse as a fiber and a fuel 

As before mentioned, bagasse is not an unused agricultural residue. A well developed 
collection system is in place to gather bagasse for the sugar industry which uses the fiber to power 
steam boilers and generate power for the mills. The sugar mills are most often entirely self powered 
by the bagasse and in some cases have surplus power or fiber. 

The independence from external power suppliers, enjoyed by the sugar industry, is not 
quickly relinquished. The acquisition of bagasse from the sugar mill is therefore complicated by 
replacement of the fiber fuel with a traditional fuel. The cost of the bagasse will likewise be 
equivalent to the price of the replacement fiael equivalent, plus the preparation costs. 

If fuel oil is the chosen replacement, as it will be in most cases, it can be expected that a mill 
in the United States would pay $1 8 per barrel for the oil. The replacement of the fiber would then 
cost $36 per bone dry ton (BDT), as two tons of *depithed dry bagasse provides the fiiel equivalent 
of one barrel of oil (The prices used for this comparison are ft^om the article from which this scenario 
was acquired). With the moist depithing cost of the bagasse added, as moist depithing of the bagasse 
is required to remove useless paper fibers and conserve fuel material, the total price of the fiber 
comes to no more than $45 per BDT- the cost to a bagasse paper manufacturer (Atchison, Pulp and 



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Paper Magazine', p. 128), 

* Moist depitliing bagasse is the process of removing fibers which are not useful for paper making. 
This can amount to a left over fiber weight of 35% to 50% of the original mass, this depending on 
the quality of fiber needed by the paper mill. The bagasse pith is a perfectly suitable fuel and is 
consumed by the sugar mill. 



Bagasse's fiber characteristics 

The bagasse chemical and fiber composition is as follows (figures are taken from the dry 
cane stalk after the cane juice has been removed)- 

1) Pith: 30%, most of which is in the center, but does extend through the rind- O.mm fiber length. 
Pith pulping is chemically intensive and provides almost no usable pulp in chemical pulping 
operations. The pith has low drainage properties, low opacity, and low strength, making it unusable 
in mechanical pulping operations also. 

2) Inner Fiber: 15%, these bundles and vessels are of relatively short fiber length but are of better 
quality than the pith, and they can result in acceptable quality pulp. They do produce less pulp which 
is of poorer quality than the long rind fibers. In some cases it is recommended that these fibers are 
removed before pulping. 

3) Long Fiber: 50%, these strong fiber bundles come fi-om the external rind layer, and are superior 
to all other elements of the cane stalk- 1.4 mm fiber length. 

4)Epidemiis: 5%, this is dense and non-fibrous/non-usefiil. The total amount of fiber in the clean 
dry stalk is either 65%, or 50% strong fiber if the short fiber is counted with the pith (Upadhyaya, 
PR#20, p.55). 



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With all nonwood plant libers, Ihe decision ol' which fibers to use is a determinant in the 
quality of the paper and it's machine runability. Surprisingly, this information is relatively new. 
Many nonwood plant fiber mills of the past were unsuccessful because they pulped the entire plant, 
having lacked good information on fiber characteristics.. Additionally, plant fibers were pulped like 
wood fibers instead of being pulped with their own physical characteristics in mind, and before 
pulping the raw material was not protected from physical degradation which reduces yield and paper 
strength. There are numerous factors which contributed to the past failures by making the resultant 
product unsatisfactory compared to wood based paper, but these problems are no longer relevant 
with current infonnation and machinery. It has only been in recent years that the information on the 
pulping of pianttlbers has been developed to efficient levels. Now a resurgence of there use is 
warranted, and offers an opportunity to conserve our forests while meeting our paper needs 

Bagasse Deterioration 

Improper storage of bagasse has traditionally been of the leading causes of bagasse mill 
failures. Bagasse is harvested for 5-6 months per year. This harvest period is longer than that of 
most agricultural crops, but obviously does not support an operation's fiber needs for the entire year. 
For this reason long tenn bagasse storage methods have been developed. When improperly stored, 
yield is decreased and the fibers degrade, making pulping difficult and less efficient. The next 
leading cause of bagasse mill failure has been unsatisfactory depithing. The result of having pith in 
the paper fiber is a weakened paper with poor drainage qualities, because the small pith fibers 
impede the bonding of the good fibers. In addition, small fibers also retain water on a paper 
machine. Pulp starts it's conversion to paper at a very low solids level. As it runs over the machine, 
water is removed by dryers and the fibers bond together making the paper solid and strong. 

Micro-organisms, dissimilar tissue, residual sugars in the stalk, and the storage environment 
are the factors which have the greatest effect in the deterioration of bagasse. Rangamannar's paper in 



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the Nonwood i^lantliber Pulping I^rogress Report til I , p. 1 29, gives the authoritative analysis of 
bagasse deterioration. He says chemical degradation of bagasse is a result of bio-chemical reactions 
which are variant in intensity, subject to temperature, pH, nutrient availability, and the extent to 
which oxygen permeates the pile. 

Maintenance of low aerobicity is a factor which must be controlled to ensure success in 
bagasse storage. The compact, anaerobic storage of the bagasse pile inhibits the reactions caused by 
oxygen, and results in good quality bagasse. The fiber by-product of the sugar mill will have a 2.5 - 
3% sugar content when going into storage. Under aerobic conditions these sugars are oxidized to 
water and C02. This exothermic reaction generates approximately 1350 calories of heat per gram 
mole of sucrose, thus increasing the bagasse pile temperature. Above 22 degrees Celsius yeast 
activity decreases, and cellulose attacking organisms are generated. Cellulose is the main 
component of the fiber, hence the importance of maintaining the temperature of the storage facility, 
as the bagasse pile temperature will inevitably increase on its own and must be moderated. 

The physical effect deterioration has on bagasse is discoloration. It is a result of some of the 
same factors which cause chemical deterioration, and is likewise inhibited while protecting the pile 
from chemical deterioration. It is the actions of the aerobic environment, heat, and light which 
accelerate the physical degradation of bagasse. This is cleariy demonstrated by shading from the 
outer to the inner pile turning from dark to light,. This effects the color of the paper produced, the 
amount of bleaching necessary, and in the end the cost. 

A bagasse pile can be protected from deterioration through a chemical process Rangamaner 
describes as the promotion of growth of non-cellulolytic micro-organisms that may retard or prevent 
the proliferation of cellulose attacking micro-organisms. Apparently there are two methods available 
to promote the growth of non-cellulolytic micro-organisms. The first method involves the promotion 



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of acid producing bacteria, which uses the natural evolution of fermentation in a closed system in the 
presence of fermentable sugars and absence of air. The second method is by promoting the 
predominance of mesophilic (growing best at moderate temperatures between 25 and 40 degrees 
Celsius) micro-organisms, which involves controlling the flow of air through the pile to create a 
controlled temperature environment for the mesophilic bacteria and yeast to dominate. The growth 
of other cellulose attacking organisms are retarded by reducing the moisture content of the pile. 

The Bagatex-20 process is a new process for treating, baling, and storing bagasse. By this 
method of storage, bagasse can be securely stored for more than two years without fiber deterioration 
or serious brightness deterioration. This is the first process which has allowed bagasse to be stored in 
large bales, a great benefit to a bagasse papermaking operation. It was developed for bagasse storage 
for later use as an energy source in sugar mills. Testing has so far concluded that the process makes 
no change in cellulose, hemicellulose, or lignin after the treatment is applied and the bagasse remains 
suitable for paper production (Atchison, PR# 1 8, p. 1 1 ). 

The bagasse is dried rapidly in 600 to 900 kg bales fi^om a moisture content of 50% to 20% 
or less. This is accomplished by adding a bio-chemical catalyst which causes a controlled 
acceleration of micro-biological fermentation of residual sugars without the use of an external fuel. 
Moisture must below 20% where the micro-organisms which damage the bagasse cellulose can not 
live or are relatively inactive. The bagasse should be mechanically moist depithed at the sugar mill 
before it is treated and baled. Then the bagasse can be transported over long distances and a satelUte 
mill operation (explained in second proceeding section on India) is no longer necessary to develop a 
successful bagasse pulp and paper mill (Atchison, PR#18, p. 1 1). 

Bagasse Paper Industry Development in India 

India is setting a standard in developing progressive policies towards utilization of bagasse in 



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order to preserve their remaining national forests from conversion to plantation, and thereby 
protecting the biological diversity of their country. It is vital that they ease their import demands for 
paper fiber, and the government is working to mediate relationships between the sugar and paper 
industries. India's 1988 Forest Policy Act brought about changes to expand bagasse and alternative 
fiber papennaking in an eftbrt to preserve what is left of their forest and bio-diversity, reduce their 
dependence on fiber rich countries, and eventually to gain fiber independence. The Act has several 
provisions. As much as possible the forest industry should raise the raw material needed with a 
direct relationship between the people who can grow the trees and raw material, and with the factory 
giving credit, technical advice, and harvest and transportation services. There should be priority to 
employing local people and full involvement in raising trees and raw material. As they state in their 
purpose, "Natural Forests serve as a gene pool resource and help to maintain ecological balance", and 
those forests will not be made available to mdustries for undertaking plantation or for any other 
activities. Farmers, particularly small and marginal farmers, are encouraged to grow, on marginal 
and degraded lands available to them, wood species required for the industry (Rangan, PR#20, p. 1 5). 

To make the Forest Policy Act effective, and to help the sugar and paper industries create a 
mutually equitable relationship, the government of India added further recommendations and 
incentives to it's plan. The policy encourages clusters of sugar factories to set up paper and 
newsprint mills in close proximity. Furthermore, the government recommends that integrated 
sugar/paper complexes which share a central steam and power generation station be developed, 
adding energy savings, capital investment savings (one power station instead of two), and ensuring 
that all bagasse is transferred to the paper mill (Rangan, PR#20, p. 1 5). 

For the established paper mills, a plan to acquire bagasse and ensure the sugar mill's power 
supply is essential. It has been decided the paper mills are responsible for the installation of steam 
economy devices on existing coal fired boilers which are outdated and inefficient, and non-coal fired 



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boilers are to be converted to coal tired ones; iTnecessary, altogether new boilers will be purchased 
) for the sugar mills at the paper companies expense. The costs of coal storage and supply will be built 

into the cost of the bagasse supplied to the paper mill. The excise duty on printing and writing 
papers would then be exempted for papers made of 75% bagasse. Railways will give prionty of 
movement of coal to the sugar mills (Rangan, PR#20,p. 15). 

India's policy to develop the nonwood paper industry provides an example of the possibilities 
and dynamics involved in the procurement of bagasse for paper mills. In comparison though, one 
could expect the effort in America to be considerably simpler, based on the assumption that 
American sugar mills are using efficient boiler systems capable of burning coal or at least systems 
more easily converted to bum coal than the older ones described in the article on India. With the 
availability of bagasse and the ready supply of energy in America, coupled with the highly developed 
transportation systems available which can guarantee reliable fuel delivery, bagasse paper can be 
\ considered as an environmental alternative to wood paper in the United States. 1 have not found any 

infomiation concerning the pollution equivalents of burnt or incinerated bagasse to coal, so this 
ecological variable cannot be considered at this time. 



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Wheat Straw 

The largest nonwood fiber supply in the world comes from the cereal straws- wheat straw, 
rice straw, barley straw, oat straw, rye straw, grass seed straw, and flax. Wheat straw is the most 
important of these, with 100 million tons per year available in the United States. The next most 
prolific cereal straw has one-tenth of the availability of wheat straw (Wong, PR#21, p. 193). 

Ecologically there is much to be gained by developing the wheat straw paper industry-. After 
wheat is harvested, the straw stalk is burned in the field. The burning releases a considerable amount 



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of pollution into the atmosphere, including large amounts ofcarbon dioxide. By increasing straw 
I papermaking capacity, the current disposal and pollution problems created by wheat production 

could be reduced in North America. 

If wheat straw is used on a large scale, fiber supply will increase exponentially and the wheat 
fanner's income could be increased. The growing worldwide demand for p>aper products could be 
met through continued US export without an increase in virgin wood harvest, and potentially, virgin 
wood harvest could be reduced. 

Capital investment to utilize large amounts of wheat straw is intensive and market entry 
could be difficult at first. It would be interesting to see how much wood harvest would have to be 
restricted to push wood cost to a level where wheat straw could compete evenly. In this situation, it 
seems the fiber supply afforded by wheat straw could increase many fold over the fiber supply 
>! reduced by the restriction of wood supply, and over time after the straw industry had developed and 

reduced it's debt, price could reduce itself to all-time lows by the enormous supply increase. 
America has a massive supply of un-utilized wheat straw which is suitable for qualit> paper making 
if it is reinforced with other nonwood or wood pulps. The consumer interest in alternatives to wood 
fiber could support a developing niche market, optimally making it unnecessary to expand forest 
plantations (Wong, PR#21, p. 193). 

Straw Fiber's Characteristics 

Straw is composed of five parts- intemodes, nodes, leaves, ears, and rachis. It is important to 
eliminate as much of the least useful non-intemodal sections as possible because the nodes can take 
twice the chemicals to cook into pulp as the intemodes (Jeyasingam, PR#2L p. 75). A large part of 
the deleterious silica content comes fi"om the leaves and ears, so it is also critical these are removed. 



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Proportionally by weight, straw is 54.1% intemode, 16.9% leaves, 14.4% ears, 10.7%j rachis, 
and 4.2% nodes. The fibers are principally derived from bast cells and are fairly long, averaging 1 .2 
mm, but vary greatly over the range of wheat straw parts (Eroglu, PRW 1 7, p. ! 33). 

Consideration of Mill Size 

Large straw operations of 250,000 tons per year (example taken fi-om Wong) are not feasible 
by cost, or by raw material supply. For this reason "small scale satellite operations, and mixed fiber 
processing would have to be employed" in a straw paper operation (Wong, PR#2 1 , p. 1 93). 

The capital intensivity of constructing a paper mill leads constructors to utilize economies of 
scale, meaning the mill production capacity will be quite large. Analysis of a 250,000 tpy mill in 
Canada and Europe says the new mill would cost 500 - 700 million dollars. The raw material supply 
investment was massive and the after tax internal rate of return was less than 2% making this sized 
mill unviable (Wong, PR#21, p. 193) Paper mills principally based on straw fiber supply will have to 
be smaller and cheaper, using simple technology. Potentially they will also need to be attached to a 
paper mill, as producing market pulp is not as efficient as an integrated pulp and paper operation, if 
wheat straw mills are to be affordable. (Chaudhuri, PR#2 1 , p. 1 1 5). 

Collection of Straw 

Collection of straw poses little difficulty when the process of secondary mowing is 
employed. To begin, a wheat harvester removes the grain with a combine harx'ester/thresher and 
separator, and leaves the stalk containing the fiber behind in the field This is already done in the 
collection of grain. The blades are set high to avoid the rocks and dirt, and to cut through the 
narrowest part of the stem, protecting the blades edges; this leaves behind the stalk needed for paper 
production. Secondly then, a mower can come through after the harvester to cut and collect the 



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wheat straw with httic difllcuhy (Jeyasingam, PR#21, p. 75). 

Straw yield jx;r hectare can be as high 2500 kg/hectare with secondary mowing, as opposed 
to the the much lesser amount of 1000 kg/hectare average acquired from combine harvest of straw 
with the grain. By a straw yield increase, bale operation costs per hectare decrease and 
transportation costs decrease, as larger amounts of straw are collected from smaller sights 
(Jeyasingam, PR#21, p. 75). 

It takes straw roughly 100 days to mature, and then the collection period for gathering the 
straw and removing it from the fields lasts from 30 to 45 days more. It should be made into 
rectangular bales for transport, handling, and storage. Cylindrical rolls, often favored by farmers, are 
more difficult to handle, don't stack as well in transport, and are more likely to suffer to degradation 
from snow and rain than the rectangular bales. Densifying the bales is the other essential factor in 
transporting the bales efficiently, and in protecting them from the elements while they are stored. 
Covered storage is too expensive, even in the traditional side-less "Dutch bams", but extremely 
dense, interlocked rectangular bales with minimal inner space can provide suitable protection for 
straw. Optimally, stacks should be 150 meters long, 20 meters wide, and 12 meters high with loose 
straw on top, and angled for drainage (Jeyasingam, PR#2 1, p. 75). 

The impediment posed by silica 

Of the greatest drawbacks to using almost all of the nonwood plant fibers for paper 
production, and particularly the straws, is problems of silica introduced into the pulping process. 
Silica has negative effects on *black liquor recovery, and high production costs can be attributed to 
inefficient recovery of chemicals and heat. Also added are intensive maintenance costs for the 
upkeep of equipment in the paper making process, each piece of which is damaged by silica. Silica 
also degrades paper quality by affecting the finish and smoothness. The silica content in wfieat straw 



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is 4% -7%, compared to only traces Ibund in wood, so removing as much of the silica carrymg agents 

as possible is vital to the operation (Jeyasingam, PR#16, p.9). 

* Black liquor is most simply, a pulping chemical used in the paper making process. 

It has recently been found that improved washing and cleaning of wheat straw has decreased 
silica content and the resulting complications with machinery and chemical recovery. Much of the 
silica which damages manufacturing systems comes fi'om extraneous contaminating elements such 
as sand, and non-fibrous parts of the straw such as leaves; with their removal, smaller traces of silica 
have been evident (Jeyasingam, PR#2 1 , p. 163). 

Availability of wheat straw related to the land base 

Of the 100 million tons of wheat straw available annually, 50% of the straw is useful, 
converting into 50 millions tons of pulp. For comparison, the 1995 FAO forecast for wood pulp 
production capacity in 1995 is 90 million tons. 

The land base necessary to provide wheat straw fiber is of the same area as for wood fiber 
cut on a forty year rotation. In the Pacific Northwest, if the gross merchantable volume at rotation is 
300 m3/ hectare, the equivalent forest area that must be harvested to provide 500,000 tones of raw 
fiber would be 3,700 hectares/ year. The regeneration of this harvested area would be at least 40 
years. In order to provide 20 million tons of raw fibers over the 40 year rotation cycle, a forest land 
base would need to be 148,000 hectares. The typical mean increment of conifers in the North West 
is about 7.5 m3/ hectare/ year. The land base which provides wheat, and thus can provide straw for 
paper, has been allocated to this purpose and it's effects are accepted by the public. From our 
currently dedicated wheat lands, half of our production capacity could be met from wheat straw 
without any increase in the land base needed to produce that fiber supply. This is not a perfect 
scenario. The straw has to be converted to paper locally, and it is not practical for mills to have 






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straw shipped as a lumish. The fact does remain though- straw fiber equahng half'ol'our production 
J capacity is readily available and can be converted into many commercial paper products (Wong, 

PR#21,p.l93). 



Kenaf 

Kenaf is an annual plant native to central Africa and well suited for production in America's 
southern states. It also has the potential for production in the northern states if it's yield can be 
increased for the shorter northern growing season. The greatest promise for this comes through 
either genetic manipulation or fertilization. In a suitable climate kenaf grows 12 to 1 8 feet in a 1 50 
day growing season, and within it are two types of fiber- bark, and core. 

Kenaf s fiber characteristics 

The kenaf bark is 30% - 40% of the plant by weight. It consists of mainly baste fibers which 
are 3 - 4 mm. long, and slender. The core fibers make the other 60% - 65% of the plants weight, 
and are .5 to .7 mm. in length. (Rangan, PR#20, p. 1 1 3). The bark, core, and the whole stem can be 
used to produce a wide variety of papers, but for the best results the bark and core fibers should be 
separated before pulping. In the past separation was not possible, but in recent years mechanical 
fiber separation equipment and processes have been developed to make this and the subsequent 
evolution of high production mills possible. The properties of kenaf paper chemically produced 
fi-om bark fibers have matched softwood pulp at a comparable tensile strength, have tested better in 
tear strength, and have a high bulk. Opacity, porosity, and surface smoothness have been tested and 
prove to be very similar. The short fibered core pulp's properties compare to the properties of 
hardwood. The kenaf has a low tear strength compared to hardwood, but a high tensile, and a high 
burst strength (Rangan, PR#20, p. 1 13). 



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Kenat farming 

The amount of fiber produced per hectare is an important factor in raw material production 
and procurement. The average yield of a kenaf field is 1 5 tons/hectare/year. To support a 50,000 
tones of pulp per year mill at least 7,250 hectares of land are necessary for commitment to kenaf fthis 
figure considers a crop rotation period of 3 to 4 years). From this land base 1 09,000 tpy of kenaf at 
10% moisture are necessary to produce the 50,000 tpy, as a 46% pulp yield can be expected from the 
kenaf plant( Wong, PR#20, p.203). In comparison to many American paper mills this is quite small. 
I worked in an integrated pulp and paper mill which produced 1 ,300 tons of paper per day, and this 
level of output is not uncommon in American mills. 

Production of agricultural fiber, even for industrial purposes, is complicated. Kenaf is 
classified as an agricultural crop, and is therefore subject to government agricultural policy. These 
policies possibly make kenaf cost prohibitive to grow. Additionally, government policy can distort 
market economics and may make kenaf cost prohibitive for the pulp mill to use as a fiber source. 
Additionally, without an open market supply of kenaf to furnish a mill, governmental policy change 
or harvest trouble can leave the mill without fiber. These are serious concerns for any investor in a 
kenaf mill, so for kenaf to become the sole furnish of a paper mill, these supply concerns must be 
resolved (Wong, PR#20, p.203). 

Storage of Kenaf 

As with all nonwood plant fibers, the importance of a good storage procedure is a 
determining factor in the success of a paper mill using kenaf furnish. Over time, kenaf fibers, if they 
are not protected, are subject to deterioration fi-om moisture exposure. 



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Kenaf s bulk is a storage impediment which must be accounted for in planning a kenaf mill. 
The most effective way to store kenaf is in a densitled bale. When the bale is compressed to 500 
kg/m3, the storage area, in volume, for a one year supply of kenaf stem is 21 7,000 cubic meters. 
This will supply a 50,000 tons pulp/year chemical pulp mill whose supporting agricultural land base 
was postulated above. The optimal stacking height of a kenaf bale is 3 x 3 meters, and stacks should 
be spaced 3 meters apart. Consistent with the example mill, the estimated storage yard is 1 50 
hectares, or about 373 acres, for a one year supply of kenaf A mill carries 18 to 24 months of supply 
for security, and the supply must be protected from the elements. Rain deterioration will decrease 
the density and stability of the bale and make handling difficult (Wong, PR#20, p.203). 



Economic comparison of kenaf to wood 

Kenaf is more expensive to raise than traditional wood. The 1990 price comparison is as 
follows- Southern USA pine chips are $47/ dry ton, and hardwood is $36/ dry ton. Kenaf over other 
crops or fallow is $50 to $100/ bone dry ton, covering the cost of machinery operation such as 
planting, pest control, harvesting, seed, fertilizer, weedicides and possibly irrigation. Additionally, a 
kenaf operation is unfamiliar in the United States, and therefore it can be expected that other 
problems in the production of paper from kenaf vsdll arise, adding fiirther increases in operation and 
production costs. 

When considering the demand for ecological and exotic products, kenaf may be viable in the 
market if produced on a relatively small scale. In the present though, it clearly can not compete with 
wood on a large scale production basis as a replacement for wood paper. A possibility,' would be the 
government subsidizing it's production as an agricultural crop. This should not be considered to be 
altogether unlikely. The USDA chose kenaf over thousands of other crops for ha\ing the greatest 



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potential as a fiber crop which would not compete with agricultural crops which are now in surplus. 
^J They are spending about I million dollars annually on the research and development of kenaf for 

paper. 

Deferment of sewage sludge from waste stream to kenaf fields 

Waste water treatment facilities treat sewage aerobically and anaerobicaliy, the result of 
these treatments is digested solid sewage sludge. The waste product, cellular protoplasm, and 
aerobic microorganisms of aerobically digested sewage carry a high percentage of organic matter. 
When the aerobically digested sludge is added to agricultural land, the tilth is increased by 
improvement in aggregation and water holding capacity. The sludge's organic matter is rich with 
nutrients, and can supplement or replace the need for inorganic fertilizer. It is not safe to use sewage 
sludge on food crop land because contaminants such as heavy metals are left in the soil by the sludge 
and absorbed into food, but on nonfood crop lands, sludged soil is an excellent fertilizer. 

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In the test area used by the authors of the paper on this topic, the sludge was applied throu^ 

a flood irrigation system designed to disperse the sludge on land set adjacent to the facilit>' which is 

usually used for the cultivation of landscape shrubs. Fertilizer added to the sludged kenaf field added 

little or no additional growth when compared to kenaf treated only with sludge. With sludge 

fertilization, the stalk yields substantially increased while the diameter of the stalk decreased The 

spreading of sludge damages small kenaf plants, so they should be planted in raised beds so that the 

application of the sludge will not harm the immature plants. Overall, it was found that aerobically 

treated sewage sludge is feasible as a kenaf fertilizer, and inorganic commercial fertilizer is 

unnecessary when sewage sludge is available (Webber, PR#21, p. 19). 

Conclusion: Fiber supply outlook and production future 



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The fiber supply outlook for the Uniled States is good. We currently export thirty-two 
percent of the fiber we harvest from our forests; clearly the demands of the American consumers, 
even continuing to be considerably higher than the demands of all other nations consumers, will be 
met in the future. This though, is not the case throughout the rest of the world. Demand for paper 
products is increasing steadily throughout the world at a considerably greater rate than it is m 
America. This is largely a result of the literacy rate increase and population increase, particularly in 
developing countries. Demand for fiber is changing the way in which fiber is produced, and putting 
the United States paper industry in a position where to be competitive we v/ill have to radically 
change the ways in which we acquire our fiber to remain competitive. 

Fiber plantation is the future technique designed to increase the yield and decrease the cost of 
acquiring fiber. South American fiber plantations are getting underway, and they are expected to 
become the world's leading fiber suppliers in the coming years. A fiber plantation is intensive 
control and growth of the forest environment. A homogeneous block of single species trees are 
planted in rows, with the undergrowth controlled to allow maximum survival and efficiency. A 
virtual corridor of trees is simple to imagine as the replacement for what we today consider forest. 
Many of these plantations will produce genetically developed trees which are harvested on a short 
rotation. Paper mills are often better suited to handle smaller logs, as opposed to the much larger 
trees used for lumber, for which these are perfect. 

Presently, the largest tree plantation establishments are found in Oceana, Afiica, and South 
America. Their current contribution to the global fiber supply amounts to 19% of the hardwoods, 
and 7% of the conifers- 1 1% overall. This does not appear to be substantial, but the lower cost of the 
fiber produced on these plantations, and their continued growth, has changed the production 
economics and the competitive structure of the wood market. These plantations are able to undercut 
traditional suppliers of wood fiber, whose resources are increasing in cost and decreasing in 



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substantive availability making the American forest products industry uncompetitive in the near 
future. These plantations are growing in number as more of the developing world is llnding 
economic opportunity in fiber production, and this is leading to a revolution in wood fiber supply 
methods and economics which will be realized throughout the next decade (Hagler, p. 1 19j. 

The current American forest base is 90% naturally regenerated forest, Naturally regenerated 
forest is defined as those areas harvested for forest products or agriculture which naturally reseed or 
regenerate from coppice. The coming fiber plantations will dramatically change the face of the 
forest environment, resulting in a substantially negative impact on wildlife, biological diversity, and 
the ecological environment as a whole. 

While many people are unaware, there is a great part of the American public and the 
scientific community who feel the cost of restructuring the industrial forests of North America, while 
unquantifiable in monetary figures, is too great. If America can compete only m such a manner, then 
the market should be protected and fiber products should be supplied to American's through 
environmentally sustainable forestry based upon ecological science. With an availability of raw 
material in-excess of 100,000,000 tons per year fi-om only two of the three nonwood plant fibers 
discussed in this paper, and a with growing desire by the public for environmentally oriented 
business practice, the United States should look to protect the forest environment by not following 
the path market economics dictates. We should develop the path of forest preservation by expanding 
the utilization of nonwood plant fibers for meeting the paper needs of the public. 



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