ETHYL ALCOHOL FROM WOOD WASTE. 
35 
the instantaneous cooks no great difference in total sugars will be 
noted. Figure 3, series Ilia, shows a gradual decrease in the 1.4 
per cent acid series, and a slight increase followed by a decrease in 
the 2.5 per cent acid series in total sugar yields; whereas figure 4, 
preliminary series III, shows practically no difference in a 0, 15, or 
30 minute period. As shown in figure 3, however, decided increases 
were attained in the portion of total sugars which is fermentable, 
with increased alcohol yields (fig. 5), especially in the 2.5 per cent 
acid series. In this series the maximum yield was 8.54 per cent of 
alcohol, after which the yield dropped, although the yield of ferment- 
able sugars kept on increasing. The total sugar yield, however, 
40 
30 
20 
XVII 
XV 
y 
X 
■1 
XVI 
2 10 
2 4 6 8 10 12 14 16 18 20 22 24 
YIELD IN % OF TOTAL SUGAR IN DRY WEIGHT OF WOOD 
Fig. 4.— Preliminary series III, showing the variations in yield of total sugars with varying periods of 
cooking. Cooking pressure, 7.5 atmospheres. 
decreased at a greater rate than the above increase, and gave lower 
alcohol yields. 
Here again the data would permit of only doubtful interpretation 
or would lead to erroneous conclusions if only the total sugars were 
taken into account. The explanation of these results will be taken 
up later. 
RATIO OF WATER TO WOOD. 
All of the preliminary cooks were made with 400 per cent of water — 
that is, four times the dry weight of wood. This was the water 
ratio used by Simonsen, although that given in United States Patent 
No. 938308 by Ewen and Tomlinson was somewhat less than 4 to 1. 
From an operating standpoint the reduction of the amount of 
water used is greatly to be desired. The reasons for this are: First, 
