U. S. Department of Agriculture, Forest Service
In cooperation with the University of Wisconsin
FOREST PRODUCTS IN THE CHEMICAL INDUSTRIES

FOREST PRODUCTS CHEMICAL
INDUST41ES,
L. P. awle:
Many people do not realize the importance o f the forests to chemical industry nor see the necessity fo r chemists in the Forest Service . To an audience of .chef: ical engineers many connections between chemistry and forestry will occur, but it may be of interest as an introduction to give some of the more i mportant connections in e~ tail and sim p ly to mention others of less importance .
The largest chemical industry using wood as a raw material is the pulp and paper industry . In 1922 abou t
7,000,000 cords of pulpwood were consumed in the Unite d
States and Canada, of which
65 per cent was used by the chemical processes . This industry is also very particula r about the s pecies of wood it uses .
Pulpwood consists chiefly of two or three species ; spruce, balsam, hemlock, and aspen make up 80 per cent of the total .
There are several important chemicals which ar e produced largely from wood by the wood distillation process acetic acid, acetone, methanol, and formaldehyde .
Recentl y
'In_ Charge, Section of Derived Products, Forest Product s
Laboratory, Madison, Wis.
Read at meeting of Arne i e r Inet ? tut of Chemical Engineers ,
Washington, D .C ., Dec .
1923 .
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274

the first two have been made from t,h :'
~7"_TTc
Y is still the cniy cope s - _ :i sV.{.r
r : aldehyde .
Over 1,0O'),l'O0 cords r hws hat wc ; ri u c for distillation-,
The tanning ndu eery depend e largely on the for .
eats for tanning agents . Chestnut wood and 1?et 7,s , c1'e e `nut oak, and tan oak barks are the native forest products , most used for tanning ; but others are imported, such a s quebracho, mangrove, and myroholans ; and still others e lesser importance are collected in this country, such a s sumach and osage orange .
Turpentine and rosin are : forest products of grea t importance in the chemical industry . This country produce s about three- fourths and ' consumes nearly one-half the worl d v s total of these products, Which are so important in the paint , varnish, soap, and paper industries .
There are also a large number of less importan t chemibal forest products : cedar wood oil s cedar leaf oil and other needle oils ; Canada balsam and Oregon balsam ; variou s medicinal barks, such as' cascara sagrada and slippery elm ; galactan, which has become a commerc a .i source of ,iucic acid ; and various sugars and Gums .
Our temperate zone forests ar e not so prolific in these miscellaneous chemical products a s are the tropical forests, but the list just given is impressive and other produ;.cts may be developed .
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Wood as a structural material is also of import icd in chemical industry, since is resistant to th e chemical action of weak acids and can be used in tanks , towers, and pipes in contact with chemicals which migh t corrode iron or steel .
Enough has been said to show the value o C h forests to the chemical industries and to account for Lh e interest which the chemical industries should take in forest conservation . It might be of interest do ., :°rM 7me of the methods employed by the Forest Service in promoting forest conservation .
I nstead of giving the silticultura l side of the program it is probably better . with an audienc e of chemical engineers, to show how therm -ai research is use d in forest conservation .
Some time ago it was decided that
efficiency in the utilization of forest products was a very timportant part of any forestry program, and the "Products " work of the Po:rest Service was the result .
The work o n better utilization of wood is divided into seven principa l fields, the purpose of each bein g
Research for Better Utilizatio n
1.
The use of less wood in constructio n work through more complete knowledge o f strength end grades srei
2. Reduction of waste or derede throug h better methods; of production, particular ly in dry ing
;.,
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3 Higher yields (or in general greate r efficiency) in chemical processes usir g wood as a raw material .
4.
Use of new and less costly species .
5 .
U se of waste wood instead of more valuable wood .
6. Waste wood utilization by new methods .
7. Prevention of decay in wood .
The first two of these fields are purely mechanical and physical, and no attempt will be made to elaborat e on the research which has been carried on to bring about these results although it has been important and successful . In all the other fields chemical research has bee n employed (in the last two of them chemical research exclusively), and some examples of the work and the results will b e given .
In order to bring about the utilization of new , cheap, and plentiful species as substitutes for the more ex pensive species a fairly complete study has been made of th e paper making qualities of nearly a hundred American woods .
The yields and quality of the pulp made by the soda, sulphate , and sulphite processes have been determined, and in several cases satisfactory substitutes have been found for the common pulpwood, spruce, in making both sulphite and sulphat e pulps.
Many hardwoods have been distilled to find th e yields of acetic acid, methanol, and charcoal ; and it ha s
1

been found that several ,pec1e' :- g ,' e ea good jie ds as the , beech, birch, and maple which had been used al .:aost exclusively since the foundation of the industry , this country .
The development of the use of waste wood it plac e of wood prepared especially for a certain process is mor e a process of education and persuasion than one of research .
For instance, the use of spruce slabs by pulp mill in plac e of the round or split pulpwood is difficult . to develop, al though from the chemical standpoint the slabs are certainly as good. It has been shown by experimental work that th e slabs (including bark) of certain species of hardwood give at least as much alcohol and acid as the heartwood . Such information ought to lead to the utilization of more mil l waste .
Certain finely d i' ided :- c'rios of vas to q such a s sawdust, can not be used the same as cordwood for chemical purposes even though they have the same chemical composition. For instance, sawdust can not be destructively distilled in the same kind of apparatus that will handle cordwood and a chemical pulp made from sawdust is not suitabl e for paper making on account of the shortness of the fibers .
These examples show the need of investigation to adapt waste materials to other uses .
The production of higher elds :ti' any chemical process using wood c t'aw ?"ia ;,er.
ial i s cL dire° ,
; g ib
•r?' in
2 i4 5-

od Qpnsumpt ion, and Trmany of our ntiTest a t ~
, have bee n
t.owar•+d' this enr~ . .
:ln the harciwo od (list illat io n indtAa try, a G
Yffodif Gati o :i of fix
±114 procedure has teen intro -
result of our experiments, which g ices 5 to 1 0
,
4 p yi ] s of the chemical producto .
More recent word ha& s.o
m the pos; bi,l`5:ty m•
;t l reasing the ale-ohol yl„e.lds by at le .a'st 50 per dent :
,bp ._t ea;ti .
the
• wood with as littl e as 0 .5 per . cent s idi z l e ar? o.*ae
This has not yet been . tried 0)2 A, commercial
;s•ea .e, but arrangements have been made
in ,t ae a ;t r l near: future .' c
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No
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Mary refine nts ' in• Cookirg procedur e st d.ied to increase the yield d of fdeieric y phite and sulphate pulp manufacture, It has that ixr., l the chemical pree •s:ses
.'fo-r making pulp the rate r_+of ;t ha:s' :a, great ami"l ence on the yiel d if.
w i `
-of pulp, whiQh can. ,ire inoTta,S .d
fi'ren., 10 to 20 per cent b y r:; ,r allow cent
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.
edits 1 lave
At* 4f chemicals, t =-Ta cae o
' con-
1
~. : r"?
X1+ sib , laws ned int:or . . 3if .Ole
,e
.'= rte ions, proceed-
1 d
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'I ' q'SerAt ion, tray e. rri;r 'i
1a, opera n 'r* a ~~ru df thum1" t-o pr •se chemical basis .
h'. ~manifold uses fff'-t,esed ptlp con : z ; r •9:Ve t.e a ► ob-

c
ie the only cheap and ;.)l-nt Mfr
:L' raw . . ;_ which can be used for parer aJ i t
The previou9ly meati eed weeearch oaw e b e -el in connection with industi lee a~ reaC 7 i J 0 om e eiL .i
c crest iC :i .
In order to Inca ea se the utilization of c` rt
1 n n e c f waste, such as softwood sawdust, it has been ne-;e,„i-%?,:y t o develop new methods or further to investi gate su ;= es ed methods which had not been sufficiently aaccessful e se large quantities cf waste ., Much new information her, been gained on the processes of making cattle foed and. etli alcohol from softwoods by hydrolysis with dilute acids, an d
it is hoped that the work now under way may result in th e successful commercial manufacture of both of these product s from wood waste .
Some of our experimental work has resulted in th e utilization of waste wocd from western la_eeh through th e extraction of the galactan found in this Toed and the manufacture from it of galactose and mucic acid . In a simila r manner our studies of the color : matter i n the wood of usage orange have led to the successful commercial manufacture of a dyeing and tanning extract from waste wood o f that species. Although waste utilization methods have been found for certain species like these, it has been becaus e extractives of unusual character were fund in the wood . We have not yet developed any -che : i cal. me tree of waste utiliza tion suitable for all forms and species .
7_

By far the greatest preventable de strut t ac f 3 wood products is decay: The -prove : tion of decay Le there fore potentially the most Lepertan f a c oxia_ J_e se o i the drain on the forests The pr a servat o i 1 :L aga l.n
3 t decay has been a commercial process for many year,, . bi z there is still much to learn about the process . mach wood is still used without preservative treatment in situation s favorable to decay .
Tests of preservatives and methods of injecting them into wood have been tud ied . Some species are comparatively easy to impregnate, while others resist the penetration of preservatives and it has been necessary to ,develop treating methods for each species which will give the penetration and absorption of preservatives necessary to pro vide adequate protection.
Railway
posts, poles and piling, dock and other structural timbers are corairg more and more to b e treated with preservatives to prevent decay . Marine structures are also being treated to prevent borer attack . Service test records on installations of both treated and untreated timbers are kept . Periodic inspections add to th e bulk of authentic information, making it of great value
estimating the probable durability of structures and in spec ifyirg the preservative or method of application best suited
a given construction .
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0
Coal-tar cieosote and zinc chloride are th e most widely u's ed a preservative,3 , bu o there have been i'on n that are good for special uses:
These brief statements give a general vie: o f the importance and the varied character of the chemical wor k of the Forest Service . One other point not touched upo n should be emphasized . Although our research work is industrial research and industrial application is always the en d in view yet, like other large industrial research org :nisations, we have nct hesitated to devote a considerable pro portion of our effort to fundamental scientific research .
We have felt that the more information we have on the general subject of the chemical composition of wood, the mor e rapid and successful will be our specific investigations on chemical methods for utilizing wood . We have therefore kep t in progress projects on the chemical composition of wood, an d especially one on the analysis of species, both heartwoo d and sapwood, and we now have a compilation of data on thi s
Subject far in advance of that available elsewhere . These data have not only been of much indirect and more or less:, intangible assistance to our more practical research project s or to industrial operations, but have directly reculted i n commercial application in the cases of western larch and osag e orange woods, as already mentioned .
274 9-

In connection with the general study of woo s preservatives we have also earned on consielrable funda mental dcientific work on such s eemii
;riv La_i en d practical subjects as wT,h:T and how does a woo :1 ,ire s e g-vative preserve?" and "What is the relation b:e r Teen shemi. :al composition, physical characteristics, and preseIv .Ll e value?" Here again the -information obtained has
on3.-; been of indirect assistance to the industry, but lately , when a new preservative for very special use was required , it was possible from theoretical considerations alone t o recommend a new, cheap, and satisfactory mixture .
It is understood that this meeting was held i n
Washington largely for the purpose of studying the chemica l work of the government departments and that these paper s are mainly preparation for later inspection of the laborat c ries . Unfortunately, you will not be able to do this in th e case of the work just described since our chemical researc h is carried on at the Forest Products Laboratory ; Madison,
Wisconsin .
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