ETHYL ALCOHOL FROM WOOD WASTE. 
33 
purposes, therefore, there is no advantage in exceeding 7.5 atmos- 
pheres (112 to 115 pounds per square inch gauge pressure), for above 
this point decomposition of sugar sets in. The decomposition of 
the fermentable sugars was apparently not so great as that of the 
nonfermentable sugars, and the final alcohol yield was, therefore, not 
greatly affected; but the increased amounts of volatile acids formed 
are undesirable because of the possibility of an inhibiting action 
during fermentation. 
LENGTH OF TIME OF COOKING. 
When the pressure of 7.5 atmospheres was used as a constant, and 
when the time of cooking was varied, the following results were 
were obtained: 
Preliminary Series III. 
Time variable; 1.8 to 1.S5 per cent of H2SO4; 400 per cent of H 2 0; 7.5 atmospheres. 
Time of 
cook, min- 
utes. 
Per cent of 
total 
sugars. 
Per cent of 
total 
sugars fer- 
mentable. 
Alcohol yields. 
Cook No. 
Per cent of 
dry wood. 
Gallons ab- 
solute per 
ton. 
15 . 



15 
30 
22.59 
22.70 
23.16 
22.85 
22.95 
1 54. 87 
6.096 
16 
21 1 
18 
17 
1 Cook 21 had 300 per cent water instead of 400 per cent. 
Series III. 
Time variable; 2.50 per cent of H 2 S0 4 ; 125 per cent of H2O2; 7.5 atmospheres. 
Time of 
cook, min- 
utes. 
Per cent of 
total 
sugars. 
Per cent of 
total 
sugars fer- 
mentable. 
Alcohol yields. 
Cook No. 
Per cent of 
dry wood. 
Gallons ab- 
solute per 
ton. 
31 


21.45 
22.77 
63.66 
62. 65 
6.859 
6. 994 
20.75 
45 
21.15 

22.11 
63.16 
6.927 
20.95 
32 
10 
10 
21. 32 
23 40 
69.79 
67.27 
7.339 
7.984 
22.20 
47 
24.15 
Average 
10 
22.36 
68. 53 
7.662 
23. 18 
46 
20 
23. 61 
21.56 
18.06 
71.44 
77.15 
81.40 
8.537 
8.295 
7.387 
25.82 
56 
45 
90 
25 09 
22.34 
54976°— 22— Bull. 083- 
