ETHYL ALCOHOL FROM WOOD WASTE. 63 
volatile-acid production from some of the broad-leaved woods is as 
great as that from the same species by the destructive-distillation 
process. 
10. Sulphuric acid and possibly some sulphates are the best 
catalysts if cost, technical conditions, and yields are all considered. 
11. Chlorides prohibit fermentation, but tannin in the concentra- 
tions as ordinarily obtained does not. 
PLANT EQUIPMENT AND OPERATION. 
The essential parts of a plant equipped to produce ethyl alcohol 
from wood, considered in the order of their use, are as follows: 
1. Adequate sawdust storage. 
2. Disintegrating equipment — hogs, screens, and shredders. 
3. Sawdust storage above digesters, and acid storage. 
4. Digesters. 
5. Diffusion battery. 
6. Neutralizing and settling tanks. 
7. Coolers. 
8. Fermenters and yeast equipment. 49 
9. Beer still. 49 
10. Rectifying still. 49 
11. Bonded warehouse. 49 
12. Boilers and engines. 
13. Laboratory and office. 
14. Charcoal rectifiers (desirable, but not absolutely necessary). 
SAWDUST STORAGE. 
What constitutes adequate sawdust storage will depend upon the 
location and the continuity of operation of the sawmill and upon 
the character of the logging operation. The operation of the alcohol 
plant and distillery must be continuous. The storage, therefore, 
must be adequate to make it possible for the plant to comply with 
the regulations of the Bureau of Internal Revenue governing the 
operation of distilleries. These alcohol plants are surveyed as to 
their output and must produce daily the amount required in the 
survey; if they do not produce that amount, they are penalized 
with the tax on such a quantity of alcohol as is necessary to make 
up the amount required by the survey. In general, therefore, the 
alcohol plant should have at least 15 days' supply of wood on hand; 
and, if the logging operations require frequent shutdowns, the 
alcohol plant should always have sufficient material in storage to 
last twice as long as the average shutdown. The waste may be 
best stored and handled in the condition in which it is ready for use, 
that is, hogged and shredded. Protection from the rain is all that 
is needed, and any type of open-walled, covered building would be 
suitable. Belt conveyors may be used to handle the material, and 
* 9 These items must be approved and supervised by the U. S. Bureau of Internal Revenue. 
