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 H2O ; 7.5 atmospheres. 



Cook No. 



Catalyst. 



Total 

 sugars. 



Per cent of 

 total sugars 

 ferment- 

 able. 



Alcohol yield. 



Per cent of Gallons 

 dry wood. per ton. 



54 



1.8 per cent of H 2 S0 4 



21.96 

 } 21.40 



59.29 

 63.23 



6.805 

 6.927 



20. 58 





/I. 8 per cent of H2SO4 





104 



\0.1 per cent of FeSO* 



20. 9 i 













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 



108 





17.93 

 19.25 



60.13 

 59.18 



5.583 

 5.077 



16.89 



0.5 niter cake, 0.5 H2SO4 



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. 



