ETHYL ALCOHOL FROM WOOD WASTE. 



39 



would probably have reduced these variations, but they were not 

 deemed necessary to establish the principle involved. 



Although 100 per cent of water gave results practically as good as 

 did larger amounts, the operating conditions chosen for future work 

 was 125 per cent of water. This was done for two reasons: First, 

 to insure a better mixture of the acid in the wood, which, of course, 

 is easier to accomplish with larger amounts of water, and, second, 

 to use the maximum amount of water possible and still obtain a 

 digested sawdust that has no drip. The advantages from the use 

 of 125 per cent of water were felt to outweigh the small increase in 

 steam consumption and to justify its adoption for future work. 

 From calculations that have been made to determine the steam 

 load on a commercial digester it was found that it takes 1,816,000 

 B. t. u. to a cook for heating the wood and acid solution, and 1,183,000 

 B. t. u. to heat the digester— a total of 2,999,000 B. t. u. to a cook. 

 Decreasing the ratio of water to wood from 125 per cent to 100 per 

 cent would decrease the total steam load to 2,709,000 B. t. u., a 

 difference of 290,000, or about 10 per cent. The digester load, 

 however, is only 25 to 30 per cent of the total steam load of the 

 plant; consequently, the above would make a difference of only 

 2 or 2.5 per cent of the total steam load of the plant. 



RATIO OF ACID TO WOOD. 



The above ratio of water to wood (125 per cent) and a 0-minute 



cooking period were the constants used in the next series, in which 



the ratio of acid to wood was the variable. Sulphuric acid was used 



as the catalytic agent and in amounts varying from 0.5 per cent to 



4 per cent of the dry weight of the wood. The results are given in 



the following table: 



Series V. 



125 per cent of H2O; 7.5 atmospheres; minute. 









Per cent 

 H2SO4. 



Per cent of 

 total sugars. 



Per cent of 

 total sugars 

 ferment- 

 able. 



Alcohol yields. 



Cook No. 



Per cent of 

 dry wood. 



Gallons 

 absolute 

 per ton. 



38 



0.5 

 .75 

 1.00 

 1.40 

 1.40 

 1.40 



17.42 

 21.83 

 21.68 

 23.17 

 23.74 

 22.37 



43.13 

 56.03 

 56.43 

 54.20 

 53.67 

 53.92 



4.172 

 6.085 

 6.506 

 6.972 

 6.319 

 6.214 



12.62 



37 , 



18.41 



35 



19.68 



33 



21.09 



40 , 



19.11 



391 



18.80 









1.40 



23. 455 



53. 935 



6. 6455 



20.10 







34 



1.80 

 1.80 

 2.50 

 2.50 



21.96 

 21.09 

 21.45 



22.77 



59.29 

 60.68 

 63.66 

 62.65 



6.805 

 6.440 

 6.859 

 6.994 



20.58 



30 2 , 



19.48 



31 



19.75 



45 



21.15 









2.50 



22.11 



63. 155 



6. 9265 



20.95 







36 



4.00 



21.10 



66.63 



7.000 



21.17 







1 Blow-off open, not averaged. 



2 30 to 100 per cent H2O, not averaged. 



