YIELDS FROM DISTILLATION OF CERTAIN HARDWOODS. 



yields of alcohol. 1 The total tar yields follow almost the same order 

 as the alcohol yields. The yields of charcoal, on the other hand, tend 

 to follow the reverse order, but with more exceptions. The lowest 

 yield of charcoal and the highest yields of alcohol and of tar are 

 obtained from one species hickory; while the highest yield of charcoal 

 and the lowest yields of alcohol and of tar are also obtained from one 

 species chestnut. 



TABLE 3. Average yields of alcohol, total tar, and charcoal from, the heartwood of various 

 xj)t'<-ies, in percentages of dry weight cf material distilled. 



YIELDS PER CORD. 



ALCOHOL AND ACETATE. 



COMPARISON OP YIELDS. 



Table 4 shows the same results as Table 2, but expressed in different 

 units the raw material in terms of gallons of 82 per cent wood alcohol 

 and pounds of 80 per cent acetate of lime. 



The yields from the various species on a cord basis are quite different 

 from the yields on a unit weight basis ; the heavier woods, such as 

 hickory and oak, are advanced in relative position, and the lighter 

 woods, such as chestnut and red gum, are reduced. 



The average yield of alcohol from Indiana beech and Wisconsin 

 birch and maple is 10.9 gallons per cord; the yield from these species 

 from Pennsylvania is 11.51 gallons per cord. These figures represent 

 the average yields obtained at commercial plants in these localities. 2 

 The average yield of acetate of lime from these two groups of woods, 

 319 pounds and 315 pounds per cord, respectively, is about 50 per 

 cent higher than the average commercial yields. The yield from 

 white oak from Arkansas of 9.2 gallons alcohol is very close to that 

 being obtained in one commercial plant, and the acetate yield of 262 

 pounds per cord is, as in the case of the standard species, about 50 

 per cent higher than the commercial yield. The only ways in which 

 the experimental distillations differed from commercial conditions 

 were the low maximum temperatures and the short distance from the 

 center of the charge to the heated surface of the retort. It is possible 

 that these two conditions, resulting in a slow and well-controlled 

 distillation, are sufficient to account for the higher yields. 



1 These averages do not include the yields from "lumber," since this material was usually very dry 

 resulting in maximum temperatures much higher than the normal, giving yields of tar and charcoal not 

 comparable with the rest of the runs. 



2 A corresponding difference between the Lake States and the Eastern States is also obtained commer- 

 cially in the acetate yields, but this difference is not shown in the laboratory yields. It must be remem- 

 bered, however, that these figures represent the average from equal proportions of the three standard species, 

 while in actual practice one species may predominate. 



