ETHYL ALCOHOL FROM WOOD WASTE. 
59 
The reason for these marked differences between the evergreens 
and the deciduous trees must reside in their chemical composition 
rather than in any physical or structural differences and, no doubt, 
may be ascribed primarily to differences in cellulose content. As a 
class, the deciduous trees contain less cellulose and more lignin and 
wood gums than the coniferous species. The gums, such as xylan 
and araban, are in part converted into the respective pentose sugars. 
This accounts for the comparatively high total sugar yields and also 
for the comparatively small portion of the sugar that is fermentable. 
Those constituents, lignin and gums, which make the hardwoods as a 
class, and especially beech, birch, and maple, desirable in destructive 
distillation, bring about a different result in alcohol production, and 
it is questionable whether commercial recovery would be possible 
from any of those species alone that are mentioned in the above table. 
If mixed in small amounts with coniferous waste, the broad-leaved 
species will not interfere with the production of sugar and alcohol 
from the coniferous waste, in spite of the large amounts of acetic and 
formic acids produced. In fact, it is when the recovery of these acids 
is considered in conjunction with the alcohol process that hardwood 
waste utilization appears possible if the waste is available in sufficient 
quantity. 
Ordinary destructive distillation practice recovers 180 pounds of 
crude acetate of lime per cord of wood. Under good conditions this 
may be brought up to 200 or 220 pounds per cord. 
The following table shows the amounts of acetic and formic acid 
produced from beech, birch, and maple, the three species commonly 
distilled : 
Cook No. 
Species. 
Acetic acid 
(per cent 
of original 
dry wood). 
Formic 
acid (per 
cent of 
original 
dry wood). 
Total vola- 
tile acid 
(per cent 
of original 
dry wood). 
7G 
Beech 
4.800 
4.700 
3.770 
0.445 
.706 
.512 
5.245 
62 
Birch 
5 406 
73 
Hard maple 
4.282 
The amounts of acetic acid produced, as shown in the above table, 
are equal to or greater than the amounts produced by the destructive- 
distillation process; and, aside from the technical value of the facts 
disclosed, additional light is thrown on the difference in chemical 
composition of those woods and woods of the coniferous species. 
SOURCE OF FERMENTABLE SUGAR. 
As previously outlined, the source of the fermentable sugar ob- 
tained from the hydrolysis of wood has long been a mooted question. 
Cellulose and materials higher in cellulose than wood, however, have 
