2 BULLETIN 983, U. S. DEPARTMENT OE AGRICULTURE. 
season and from year to year, before the war the average cost of the 
materials for making grain alcohol, fuel excluded, was about 27J 
cents a 188-proof gallon. Manufacturing costs, including coal, 
interest, repairs, depreciation, taxes, labor, etc., range from 10 to 17 
cents a gallon of 188-proof alcohol, depending upon the location and 
efficiency of the plant. 
One gallon of molasses yields from 0.45 to 0.48 of a gallon of 188- 
proof spirit. The price of molasses before the war averaged from 
5 to 7.5 cents a gallon, and, therefore, the approximate cost of raw 
material in a gallon of molasses spirit was from 10 to 15 cents. The 
cost of production of molasses spirit is slightly less than that of 
grain spirit, but in either case the cost of raw material is compara- 
tively high. 
One ton of dry sawdust or other wood waste (or its equivalent on 
an air-dry or green basis) will yield from 12 to 20 gallons of 188-proof 
spirit. The disposal of this waste in the vicinity of a sawmill or 
other large woodworking plant is specifically an item of loss, because 
most sawmills produce waste in excess of their own power require- 
ments. Sometimes the waste is not worth more than 30 to 50 cents 
a ton, and this makes the cost of raw material in a gallon of ethyl 
alcohol from sawdust about 2 cents. This includes also the fuel 
charge, for the residue after conversion and extraction is available 
for fuel, whereas in grain distilleries about 7 tons of coal and in 
molasses distilleries about 4 tons are required in producing 1,000 
gallons of 188-proof spirit. 
If the manufacturing cost of producing ethyl alcohol from wood 
can be reduced to the same figure or nearly the same as that for 
making it from grain or molasses, there will be a large margin in 
favor of producing the alcohol from wood waste. Of course, with 
a yield of 12 to 20 gallons from a ton of wood and 80 gallons from a 
ton of corn, the amount of material handled in certain parts of the 
plant producing alcohol from wood will be four or five times as great as 
in a grain distillery of equal producing capacity, and this will require 
a larger-sized plant and an increased operating cost. 
In recent years the production of ethyl alcohol from sawdust has 
received a great deal of attention, and a large amount of money has 
been spent in the technical development of the process. A number of 
plants have been built in this country, but only two have been con- 
sidered commercial successes. 
Because of the importance to the lumber industry of the problem 
of waste disposal, and because this process is practically the only one 
applicable to the disposal of wood waste, the Forest Service has inves- 
tigated the different processes and, so far as possible, the plants that 
have been built, in order to learn the causes of former failures and 
to aid in the commercial development and success of the processes. 
