Cellulose Industries
of the West
A pulp
mill of Crown
Willamette
Paper
Co. at Port Angeles,
Wash.
J. ELTON LODEWICK, Forest Products Analyst, Bonneville Power Administration, Portland, Ore. T h e forests of t h e West, w i t h proper m a n a g e m e n t , c a n yield i n perp e t u i t y t w o raw materials o f interest t o t h e c h e m i s t a n d c h e m i c a l engineer—cellulose a n d l i g n i n . . . W i t h t h e c h e m i c a l s required t o p r o c e s s t h e m , t h e y will p r o v i d e c o u n t l e s s a n d v a r i e d p r o d u c t s
J. HE western United States is a region of contrasts—wide open spaces thinly populated; areas of dense magnificent forest; mineral resources without stint; areas of concentrated industrial a n d agricultural activity; areas deficient in rainfall; and areas where rivers fed by bounteous rainfall a n d perpetual snows roll majestically to the sea, halting occasionally at man's command to irrigate arid but fertile soils or to generate electric power with which to process the varied resources of t h e region. Perhaps the natural resource of widest interest t o the chemist a n d chemical engineer is the forest. Under proper management, which is fast approaching a reality, it can yield in perpetuity two important basic raw materials—cellulose and lignin. These, together with the chemicals required to process them, provide employment for laborers, technicians, a n d 7 executives and yield countless products used throughout the world. Approximately one fourth of t h e commercial forest land and t w o thirds of that bearing trees of sawtimber size in the U. S. lies in t h e states west of the Great Plains. Latest estimates indicate a total wood volume in all trees on this land of 239 2696
billion cubic feet. C u r r e n t annual growth is at the rate of 2.31 billion cubic feet; this volume would be available for harvesting each year only if there were no losses from fire, insects, and decay. W h a t does this mean in t e r m s of chemical raw materials? Assuming a n average weight for dry wood of 25 lb. p e r cubic foot and a composition of roughly 6 0 % cellulose and 30% lignin, some 17 million tons of cellulose and 9 million tons of lignin are being grown each year. Under present utilization practices 3 0 % or less of the current growth finds its way into useful products. Vast acreages of virgin forest in which there is no net growth have not yet been opened up by roads because of their inaccessibility. Economic conditions have m a d e it impossible to salvage the small trees shaded out by their more vigorous companions in young densely stocked s t a n d s . The heavy equipment required for large timber makes t h e harvesting of small a n d broken trees during regular logging operations too costly. Avoidable waste in t h e sawmilling and other processing industries has been excessive—merely a n o t h e r example of the prodigal use of a natural resource commonly believed to b e inexhaustible. CHEMICAL
There is a growing realization on t h e part of t h e managers of private a n d public forest lands t h a t the forests are exhaustible but t h a t under scientific management they can be made to yield' continued crops, not equal to demand at present although, as increasing acreages are brought under management, eventually sufficient to support an industry as large as t h a t now existent. Thinking along this line was accelerated by the dearth of accessible timber during the war. The increasingly high costs of timber during this period made more complete utilization mandatory if the wood-using industries were to survive. A t the same time, inflated timber values and higher prices for the products made closer utilization economically feasible. Conservation
of Wood
Supply
It is evident that, during the interim before t h e time t h a t the managed forest becomes an actuality, the wood-using industries must go on short rations. I n order to maintain output and employment at near present levels, more complete utilization is being practiced—the same volume of timber or logs is made t o yield a greater return. T h e first step, chronologically, in this program is more complete removal of usable material from each acre of timberland harvested. This is being done mostly through relogging wherein the harvesting of t h e large timber is folloAved by logging the remaining small trees, down timber, and broken logs with AND
ENGINEERING
NEWS
lighter specialized equipment. The second step is redaction of avoidable waste during processing. 0 ; *e example will suffice, though others co-jld b e cited. A number of the larger pulp companies have installed hydraulic log barkers— machines which remove the bark by means of water jets rather than by knives or b y abrasion. Used in conjunction with wholelog chippers capable of handling logs up t o 48 inches in diameter and 40 feet long, they, effect a wood saving of 10 to 12%. T h e third step is t l i e bettor utilization of the unavoidable waste developed during processing. Slab a n d edgings and other solid pieces are reworked into small dimension stock, small material is chipped for pulp, and sawdust and hogged fuel are sold for wallboard i n s t e a d of being burned under the boilers. Integration of t h e wood-using industries so that each obtains the type and size of log most efficiently utilizable by it and so t h a t unavoidable w a s t e will be diverted to its most efficient end use also will do much to assure t h e forest industries a continued and adequate supply of their basic raw m a terial. Pulp and Paper
Industry
The sawmill industry still takes the major portion of the t i m b e r harvested in t h e West, but the pulp and paper industry, which is second i n importance from the standpoint of demand on the forest, has the greatest chemical interest. This industry has shown phenomenal growth, centering around t h e use of western hemlock rather than t h e spruce which is t h e mainstay of northeastern a n d lake s t a t e mills, or t h e pine which is used in t h e
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South. The industry is concentrated along the western coast between the Cascade M o u n t a i n s and the Pacific Ocean, w i t h 21 plants in Washington, 8 in Oregon and 5 in California. Only one plant, in northeastern Washington, is found east of the Cascade. Mountains and Sierra N e v a d a s because water supplies are scanty in t h a t area, though at least one pulp and paper mill in M o n t a n a and one in f daho are being promoted. Of t h e mills, 11 produce pulp exclusively and 3 of these specialize in dissolving pulps for rayon, one produces insulating board, a n d 3 produce paper a n d / o r fiber board. T h e remainder manufacture both pulp a n d paper. T h e pulp plants range in capacity from 50 to 450 tons per day; paper plants, from 25 to 400 tons. Total daily capacity is slightly over 5,000 tons of pulp and 3,385 tons of paper a n d board. Major recent changes in the pulp indust r y in t h e West have centered around the sulfite pulping process, inspired in large degree b y the necessity for reducing pollution. For every ton of cellulose produced over a ton of other organic material is dissolved from t h e wood, and the pollutional effect is equivalent to the daily domestic sewage from 1,500 persons. Evaporation a n d burning of calcium sulfite waste liquor have n o t been successful because of the deposition of insoluble calcium salts in the evaporators. T w o general approaches to a solution of the problem are being tried. T h e first centers around partial evaporation and chemical conversion of the waste liquor into a commercially valuable product. T h e second involves the use of a m monium or magnesium sulfite, instead of calcium sulfite, either of which eliminates the scaling problem. Under the first heading comes the production of ethyl alcohol, now being done b y one company; another is producing a road binder by evaporating the waste sulfite liquor to approximately 5 0 % solids. So far, no plant in the West has gone into the production of vanillin, t a n n i n g materials, plastics, fertilizers, or emulsifying agents for sprays, all of which are possible and all of which utilize t h e lignins in the waste liquors, but which have limited markets compared to the volumes of liquor produced each day. One comp a n y is fully converted to the a m m o n i u m base and one will be on a magnesium base by the end of the .year. T h e magnesium base has an added advantage. The liquor is evaporated to approximately 5 0 % solids and then burned; chemical recovery is almost
SEPTEMBER
2 2,
1947
100% and the energy present in the o r ganic material generates sufficient heat to generate all the process steam and power required for the pulping process, giving^ a. slight positive energy balance. Plywood Industry The plywood industry is vitally depende n t upon chemicals for its continued existence. It consists of 33 plants with 3 more under construction and 2 others proposed. T h e annual o u t p u t of this industry is equivalent t o 1.5 billion square feet of Vs-inch softwood plywood, 9 5 % of the U. S. production. Prior to t h e last war, approximately 1 0 % of the product was of t h e exterior t y p e requiring thermosetting phenolic resin glues. T h e remaining 9 0 % was interior t y p e using casein a n d vegetable protein glues, principally soybean. At present one third of western plywood production is of the exterior type, and industry leaders predict t h a t within five years little, if any, protein glue will be used in plywood. Annual glue requirements are 20,000 tons, requiring 2,000 tons of caustic a n d smaller quantities of other chemicals in their production. Expected annual plywood production when the new plants are completed will approach 2 billion square feet, with an attendant increase in chemical use. So important has gluing become t h a t phenolic resin and casein glue producers are establishing plants in t h e Pacific Northwest in order to capture t h i s a n d other wood adhesive business. The new cold-setting resin glues, mostly derived from coal distillation, are being adopted by the wood-using industry. I n dications a r e t h a t they will supplant hide a n d casein glues with increasing rapidity in the furniture a n d other we^d fabricating industries. Radiofrequeiicy curing of losin glues received a big impetus during the war. I t is now being used in the edge gluing of veneers, in t h e production of thick plywood, and in the fabrication of piano sounding boards and other built-up items. Modification of t h e resin glues to reduce arcing of the high-frequency current through the glue line will contribute to a wider use of these glues. A recently announced plastic facing for plywood is made from finely ground wood waste and a resin glue. It is substituted for the high-grade veneer now in use; if widely adopted, i t will conserve the supply of high-grade logs, open new fields of plywood use, and create a market for additional phenolic resins. Rayon and Cellophane In spite of t h e fact t h a t the Pacific Northwest supplies approximately two thirds of t h e wood pulp used in rayon and cellophane, no plants to produce these items have been established in the West. One plant to manufacture cellophane has been reported and m a y soon be established in the vicinity of Springfield, Ore. Op2697
?tions have been taken on a site with cons t r u c t i o n delayed until materials and costs 'decrease. N o d a t a are available on west*ern cellophane markets, but under the ass u m p t i o n t h a t a major p a r t would be used i n the frozen fruit and vegetable pack, over "half t h e U. S. requirements would be in the W e s t . Such a plant might be the incentive t o establish a rayon yarn mill to provide t h e needs of the textile industries in the West. Studies b y Bonneville Power Administration indicate that on a per capita basis t h e 1945 western rayon requirement for automobile tires would have been 78.8 million lb.; for textiles the requirement would have been 72.2 million lb. Just across the border in C a n a d a a 250to 400-ton-a-day development of pulp for acetate rayon is under way. Alcohol
and Wood
Preserving
T h e newest wood chemical industry in the West produces ethyl alcohol from wood a t Springfield, Ore. T h e first carload of alcohol was shipped during M a y . T h e $ 3 million plant was s t a r t e d in ] 0 i i with D P C funds a n d completed with R F C funds. A modi lied Schoeller process, known as t h e Madison wood sugar process, is used. When in full operation 225 to 250 tons of d r y wood chips, now obtained as waste from nearby sawmills, will be processed each day t o yield between 5.5 a n d 6.0 million gal. of ethyl alcohol per year. The daily by-products will a m o u n t to 100 tons of lignin, 33 tons of calcium sulfate dehydrate, 5,000 lb. of methanol, 6,000 lb. of furfural, and nearly 12 t o n s of nonfermen table sugars dissolved in about 1,800 tons of water. R e a d y markets are available for the methanol a n d furfural; lignin will be used as boiler fuel until markets a r e developed. Experiments on the use of nonfermentable sugars in t h e growing of fodder yeast a r e under way. E s t i m a t e d costs of t h e ethyl alcohol, n o t including amortization a n d ignoring by-product values, a r e 22 and 30 cents per gal. T h e P u g e t Sound P u l p and P a p e r Co. a t Bellingham, Wash., began t h e production of ethyl alcohol from waste sulfite liquor during the war and is still in full production. R a t e d capacity is l.S million gal. Mills
2698
of the Pacific
annually. T h e waste sulfite liquor is cooled in a flash cooler, y e a s t is added a n d fermentation permitted, after which t h e yeast is r e c o v e r e d b y eentrifuging a n d t h e alcohol is distilled off. The 34 p l a n t s treating piling, poles, ties, cross arms, a n d other wobd products in t h e West require large volumes of chemicals annually. A b o u t half of the p l a n t s h a v e pressure t a n k s ; t h e remainder use a steeping process. Practically every type of preservative is used including coal-tar creosote, p e t r o l e u m creosote, chlorinated phenols, zinc c h l o r i d e , Wolman salts, a n d others. T r e a t m e n t for resistance to decay and fire m a y be expected t o increase a s lumber b e c o m e s scarcer a n d more expensive, p r o m i s i n g an e x p a n d i n g future for t h e wood p r e s e r v i n g industries in t h e P a cific N o r t h w e s t . Charcoal Charcoal, a n essential source of carbon for some of t h e chemical and metallurgical industries, i s n o t in production in a p p r e ciable q u a n t i t i e s in the West. One p l a n t using b e e h i v e kilns with no by-product r e covery o p e r a t e s sporadically in western W a s h i n g t o n , using second growth Douglas fir wood. S m a l l q u a n t i t i e s of oak charcoal are i m p o r t e d from Mexico. The major portion of p r e s e n t supplies is consumed in domestic charcoal burners, not industrially. P r e s e n t industrial a n d domestic d e m a n d is insufficient t o support a minimum-sized c a r b o n i z a t i o n unit. If a sufficient d e m a n d were created b y an electrochemical o r electrometallurgical i n d u s t r y , there w o u l d b e a n a b u n d a n c e of r a w m a terial a v a i l a b l e from logging and sawmill waste a n d t h e lignin from t h e wood sugar process. Wood c r e o s o t e h a s n o t received full e n dorsement a s a wood preservative, t h o u g h laboratory t e s t s indicate t h a t its toxicity is c o m p a r a b l e to t h a t of coal-tar creosote. Control of t h e t e m p e r a t u r e of the carbonization p r o c e s s might, t h r o u g h less cracking, modify t h e properties of the t a r s a n d other f r a c t i o n s t o such a n extent t h a t t h e by-product creosotes a n d t a r s might find new uses a n d assist materially in the est a b l i s h m e n t of a charcoal industry. Lumber
Co. at Scotiii,
Calif.
C H E M I C A L
Waste Utilisation and Hydrogenatiort
of
Wood
E v e n t h e b a r k a n d chips from t h e lumbering o p e r a t i o n s a r e now b e i n g utilized. T h e Weyerhaeuser T i m b e r C o . a t Longview, Wash., now produces cork flakes, s h o r t fibers, tissue powder, a n d combinations of these t h r e e on a c o m m e r c i a l scale. B a r k represents a p p r o x i m a t e l y 1 2 % of t h e volume of a fir log b u t u n t i l recently was used only as fuel. T h e p r o d u c t s it n o w yields a r e used as e x t e n d e r s i n resin glues a n d plastics, in insecticides, a n d as soil conditioners. Extensive work h a s been d o n e on the extraction of t a n n i n from w e s t e r n hemlock bark. T h e yield of t a n n i n is high enough to m a k e t h e process economically feasible a n d the p r o d u c t is satisfactory for t h e tanning of sole leather. Unfortunately, m o s t of t h e b a r k readily a v a i l a b l e comes from logs which h a v e been floating in salt water for a considerable p e r i o d a n d t h e elimination of t h e residual salt i s expensive a n d reduces t h e yield of t a n n i n . However, when this a n d other processing difficulties h a v e been eliminated t h e way will be opened for a new Pacific cellulose industry. In the California redwood forests t h e Pacific L u m b e r C o . of San F r a n c i s c o h a s done o u t s t a n d i n g work in t h e utilization of lumbering w a s t e materials. T h e chemical characteristics which h a v e resulted in t h e exceptional life span of t h e American redwoods m a k e t h e exploitation of r e d wood waste particularly a t t r a c t i v e . F i b ers obtained from redwood chips a r e used commercially in roofing felt a n d in oil well drilling m u d , a n d are further r e d u c e d to a powder in which both t h e resin a n d t h e fibrous e x t e n d e r material a r e inherently present. A n o t h e r material d e r i v e d from redwood chip, sodium p a l c o n i t e , is expected t o find use in controlling t h e viscosity of drilling muds. Redwood b a r k which s o m e t i m e s attains a thickness of 18 inches h a s also produced valuable b y - p r o d u c t s . W o o d - t y p e building insulation a n d a textile fiber which can be mixed with wood or c o t t o n a r e m a d e from t h e b a r k fiber and t h e r e m a i n i n g fines a r e used as a soil conditioner a n d a s a r a w material from which t a n n i n - d e r i v e d a n t i oxidants a r e produced for u s e in lubricating oils. T h e s e a n t i o x i d a n t s a r e t h e same substances t h a t m a k e r e d w o o d virtually i m m u n e to weathering. T h o u g h " no commercial applications h a v e been m a d e , the h y d r o g e n a t i o n of wood p r e s e n t s a n i n t e r e s t i n g field for experimentation. In t h e presence of a n a l k a l i t h e lignin a n d some of t h e c a r b o h y d r a t e s are converted into liquid or soluble products as y e t unanalyzed. At 250°, u s i n g nickel as a catalyst, lignin s u s p e n d e d in water is converted i n t o propylcyclohexanol, methanol, a n d glycol derivatives. A t higher t e m p e r a t u r e s , phenolic c o m p o u n d s a r e produced, t o g e t h e r with cyclic alcohols a n d hydrocarbons. AND
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