Chemicals from Wood 



641 



butt logs of western larch were ex- 

 tracted with water to remove the large 

 amount of water-soluble gum that they 

 contain. The gum was chemically con- 

 verted to mucic acid, which is used as 

 the gas-liberating acid in some brands 

 of baking powder. The process was not 

 a financial success because the large 

 amount of chip residue was unused. 



A number of small plants scattered 

 about the country extract essential oils, 

 medicinals, and flavoring materials 

 from needles, bark, roots, or wood of 

 various species. Those plants, like all 

 other extraction plants, could profit 

 by chemical refining of their residues. 



DESTRUCTIVE DISTILLATION is by far 

 the oldest wood-chemical-processing 

 industry. For years the charcoal resi- 

 due was the only product sought. Char- 

 coal is used as a domestic and picnic 

 fuel ; in smelting and reducing various 

 ores; in making such chemicals as car- 

 bon bisulfide, which, in turn, is used 

 in making viscose, rayon, and cello- 

 phane, and also sodium cyanide, a 

 powerful disinfectant. 



Now a number of valuable volatile 

 products are also obtained by con- 

 densing the vapors from destructive 

 distillation. In the case of hardwoods, 

 methyl alcohol (wood alcohol), ace- 

 tone, and acetic acid are obtained as a 

 water-soluble distillate, together with 

 the water-insoluble tars and pitches. 

 Methyl alcohol is used as an antifreeze 

 agent in the radiators of automobiles, 

 for denaturing grain alcohol, as a sol- 

 vent in many industries, and for mak- 

 ing formaldehyde, which, in turn, is 

 used as a disinfectant and in making 

 plastics. Acetone is used as a solvent in 

 the rayon and plastic industries, and 

 acetic acid in making white lead paint 

 and acetate rayon and films. Yields of 

 methyl alcohol, acetone, and acetic 

 acid are lower from softwoods than 

 from hardwoods. 



The pines, however, yield consider- 

 able turpentine and softwood tar. Soft- 

 wood tar is used in the compounding 

 of rubber, to some extent in manu- 

 facturing oakum for calking ships, in 



802062 49 42 



cordage, and also in medicinals. Both 

 softwood and hardwood tars find use 

 as flotation oils in mineral separation 

 and as gasoline gum inhibitors. The 

 heavier fractions are used as preserva- 

 tives, disinfectants, and stains. The 

 pitch finds use as a waterproofing and 

 insulating agent and as a binder for 

 briquets. 



Although the products obtained by 

 the two older wood-processing meth- 

 ods named are of considerable indus- 

 trial importance and could perhaps be 

 used in larger amounts than are now 

 produced, a large expansion in their 

 production does not now seem war- 

 ranted. Any real increase in the chem- 

 ical utilization of wood will thus have 

 to be by the processes which produce 

 products that are in greater demand. 



HYDROLYSIS of wood to sugars, 

 followed in some cases by their conver- 

 sion to other products, is a most prom- 

 ising chemical approach to large-scale 

 utilization of wood residues. 



At the Forest Products Laboratory 

 it was found that sugars can be pro- 

 duced to the extent of about half the 

 weight of the wood by a simple process 

 of heating wood chips or sawdust with 

 a dilute solution of acid in water un- 

 der moderate steam pressure. These 

 sugars, which are a mixture of glucose 

 and several different pentose sugars, 

 would be difficult to purify and crystal- 

 lize, but can be evaporated easily to a 

 molasses that contains 50 percent 

 sugar. 



Experiments now under way are us- 

 ing this molasses as an animal feed. 

 The tests have been sufficient to indi- 

 cate that it is palatable to cattle and 

 sheep. If its nutrient value proves 

 equal to that of cane molasses, which 

 it resembles closely, it could find ex- 

 tensive use as a livestock feed. Pilot- 

 plant studies indicate that about 180 

 gallons of molasses can be produced 

 from a ton of dry wood at a cost that 

 should not exceed 10 cents a gallon. 

 Cane molasses sold on quantity basis 

 at 25 to 40 cents a gallon in different 

 parts of the country in 1948. If its 



