AUGUST, 1940
INDUSTRIAL AND ENGINEERING CHEMISTRY
Literature Cited Chapin, J. H., Univ. Illinois, Ph.D. thesis, 1939. Clark, A. M. (to Imperial Chem. Ind.), U. S. Patents 2,086,379 (July 6, 1937),2,128,027 (Oct. 23, 1938). Edwardes, V. P., P u l p Paper Mag. Can., Aug. 5, 1920. Foerste?, F., and Kubel, K., Z . anorg. allgem. C h . ,139, 261 (1924). Hasche, R. L., Pacific P u l p &- Paper I n d . , 1930,33. Hewson, G. W., Pearce, S. L., Pollitt, A., and Rees, R. L., SOC. Chem. Ind., Proc. Chem. Eng. Group, 15, 67 (1933). Kild, K., Mitt.Kaiser-Wilhelm I n s t . Eisenforsch., 16, 59 (1932). Howard, H., and Stantial, F. G., U. S. Patent 1,271,899 (July 9, 1918). .Jakob, AI., “Der Chemie Ingenieur”, VoI. 11, p. 301. Leipzig, Akademische Verlagsgesellschaft, 1933. ,Johnstone, H . F., Combustion, 5 , 19 (1933). .Johnstone, H. F. (to Commonwealth Edison Co.), U. S. Patent 2,082,006 (June 1, 1937). Johnstone, H . F., and Kleinschrnidt, R. V., Tram. Am. Inst. Chem. Engrs., 34, 181 (1938). Johnstone, H. F., Read, H. J., and Blankmeyer, H. W., IND. ESG. CHEM.,30, 101 (1938). .Johnstone, H. F., and Singh, A. D., Ibid., 29, 286 (1937).
1049
Johnstone, H. F., and Singh, A. D., Univ. Illinois, Eng. Ezpt. Stu. Bull. 324 (1940). Johnstone, H . F., and Singh, A. D. (to Commonwealth Edison Co.), U.S. Patent 2,161,056 (June 6, 1939). Johnstone, H. F., and Williams, G. C., IND. ENQ.CHEM., 31, 993 (1939). Lessing, R., J. SOC.Chem. I n d . , 57, 374 (193s). McAdams, W. H., “Heat Transmission”, p. 254, New York, McGraw-Hill Book Co., 1933. Martin, Geoffrey, T r a n s . Inst. Chem. Engrs. (London), 4, 164 (1926). Nusselt, W., 2. V e r . deut. I n g . , 70, 273 (1926). Pearson, J. L., Nonhebel, C., and Ulander, P. H. N., J. Inst. Fuel, 8, 119 (1935). St. Jacques, E. C., IND. ENG.CHEW,News Ed., 15, 29 (1937). Sherviood, T. K., “Absorption and Extraction”, p. 182, New k‘ork, McGraw-Hill Book Co., 1937. Singh, A. D. (to Commonwealth Edison Co.) U. 5. Patent 2,141,228 (Dec. 27, 1938). Snow, R. D., and Frey, F. E., IND. ENG.CHEM.,30, 176 (1938). Tooley, F. V., Univ. Illinois, Ph.D. thesis, 1939. PRESENTED before the Division of Industrial and Engineering Chemistry a t the 99th Meeting of the American Chemical Society, Cincinnati, Ohio.
Utilization of Waste Lignin Current Chemical Research ELWIN E. HARRIS Forest Products Laboratory, Madison, Wis.
T
HE utilization of lignin in Chemical research on the fundamental A REVIEW of some of the aspects of lignin from waste products is characteristics of lignin gives us the wastes incurred in the a picture, somewhat incomplete logging, milling, and conaiding in the solution of this problem. A in places, but nevertheless helpversion of the forest crop has been a problem for many years. knowledge of the various external groupsful in the solution of the problem hydroxyl, methoxyl, and unsaturatedof what to do with lignin. Sulfite liquors have not only aids in foretelling the reactions of lignin. For isolating lignin, wood or been a waste but a nuisance in Hydrogenation of lignin suggests a way of other plant material is subthe national waterways. Pulping liquors alone are capable jected to a hydrolytic reaction converting lignin wastes into valuable prodaided by the use of any one of of supplying annually 1,500,000 the following agents: sulfuric tons of lienin. Forest and sawucts* acid (13); hydrochloric acid mill was& constitute an addi(25); other mineral acids ( 2 2 ) ; organic acids, either those tional lignin source of several million tons annually. present in the wood (15) or added (6) pulping chemicals; Such conditions have stimulated extensive research directed bases ( 1 8 ) ; fungi ( 1 ) or hydrolytic enzymes present in wood toward finding methods of utilizing lignin. A few sulfite pulp mills have in recent years worked out means for the disposal ( 2 ) . There is no example known where lignin has been isolated without the application of hydrolytic reactions. or recovery of this waste; the sulfate and soda pulp mills dis“Native lignin” (12), the alcohol-soluble lignin obtained pose of lignin waste by evaporating and burning. Current from wood without the use of added acid, has been thought by recovery or disposal methods a t pulp mills entail the installasome investigators to exist as such in wood. Table I contains tion of equipment a t considerable expense to precipitate the the results of experimental work to determine the amount of lignin or to evaporate the pulping liquor preparatory for connative lignin that can be obtained from wood treated to preversion into other products or for burning. vent the action of hydrolytic enzymes, as compared with the More than 100 years have passed since lignin was first recamount obtained from air-dried wood or wood attacked by ognized as a constituent of plant material, but its structure is blue stain, both of which promote hydrolysis. One sample still unknown. This is because lignin does not readily split up into identifiable building units, as is the case n.ith its assowas placed in 95 per cent alcohol and extracted immediately after cutting, the other was allowed to air-dry and then was ciate cellulose. Because of the lack of adequate means of identifying lignin, a great deal of time was consumed in seekextracted. Blue stain developed in one sample that was being ing a satisfactory method for the isolation of unchanged ligstored under normal conditions before extraction. Fats and oils were removed from the dried extract by ether and carbon nin. Within the last decade lignin investigators have suctetrachloride. The residue was triturated with 70 per cent ceeded in finding the number and types of reactive groups and sulfuric acid a t 15” C. for 4 hours and otherwise treated as in certain cleavage products. This knowledge has made it posthe lignin determination. The dried residue was considered sible to correlate many of the cqnflicting ideas about lignin the lignin yield. It is recognized that compounds other than and to carry out a more definite program of research for its lignin may be present which would make these values higher utilization.
INDUSTRIAL A N D ENGINEERING CHEMIS'I'RL
1050
than the actual lignin yield. Green a.ood contsined only a small amount of native lignin. Storage or t,he action of fungi increased tlie aniount. This increase may be attrihuted to hydrolysis. TABLE 1.
~ ~ I X T R A C T I Oor N
GHEENAND AIB-I)NIEI) Wcwo ETHANOL 'rotniI : ~ L .
>laterial
t.iliI~~~~
,~'
0,n
0.Wli 2.2
131.2
0 058 1.8
4.1
(iicen mapie
8 0
Air-dried maple
18 ,I
;\spen lawduet attacked by t h o stain a
(/"a
r.8
