ETHYL ALCOHOL FROM WOOD WASTE. 
55 
sufficient interest and value to warrant further investigation. 
Reference should be made to all the data of cook No. 104, which 
was a standard cook using 1.8 per cent of sulphuric acid plus 0.1 per 
cent of ferrous sulphate. The results are given in the following 
table, along with data from cook No. 34, showing the results from 
the use of 1.8 per cent of acid without the addition of ferrous sul- 
phate. Although the differences between the two cooks are small, 
the slight increase in fermentable sugar when the ferrous sulphate 
was used is worthy of consideration. 
125 per cent of H 2 ; 7.5 atmospheres. 
Catalyst. 
Total 
sugars. 
Per cent of 
total sugars 
ferment- 
able. 
Alcohol yield. 
Cook No. 
Per cent of 
dry wood. 
Gallons 
per ton. 
34 
1 .8 per cent of H2SO4 
21.96 
\ 21.40 
59.29 
63.23 
6.805 
6.927 
20. 58 
/1.8 per cent of H2SO4 
104 
\0 1 per cent of FeS0 4 
20.97 
Two cooks were made with niter cake furnished through the cour- 
tesy of the E. I. du Pont de Nemours Co. In cook No. 107, niter cake 
only was used, and the amount of it was equivalent to 1.8 per cent of 
concentrated acid. In other words, 5.55 pounds of cake are equal to 
1 pound of 100 per cent acid. In cook No. 108 a mixture of 0.9 per 
cent of acid and niter cake equivalent to 0.9 per cent of acid, making 
a total of 1.8 per cent of acid, was used. The results follow: 
Catalyst. 
Total 
sugars. 
Per cent of 
total sugars 
ferment- 
able. 
Alcohol yields. 
Cook No. 
Per cent of 
dry wood. 
Gallons 
per ton. 
107 
17.93 
19.25 
60.13 
59.18 
5.583 
5.077 
16.80 
108 
0.5 niter cake. 0.5 H^SO,, 
15.38 
When these results are compared with those obtained from the 
use of acid alone, it is found that niter cake will produce, either alone 
or when mixed with as high as 50 per cent of the usual acid concentra- 
tion, 75 or 80 per cent of the yield obtained with sulphuric acid alone. 
These experiments suggest interesting possibilities, provided the 
niter cake can be obtained at an appreciable saving as compared 
with the cost of sulphuric acid. 
