Wells: Destructive Distillation 



115 



tion, which began between 265° and 275° C. During this period 

 the current was shut off until the reaction subsided in violence 

 and was then immediately applied. The current was shut off 

 to prevent a loss by overtaxing the condensing system. 



In the slow, or controlled, distillation the current was so ap- 

 plied that the apparent moisture was first driven off. The 

 moisture was considered driven off when a temperature was 

 reached at which there was a decided pause in the distillation. 

 This pause occurred at different temperatures for different classes 

 of wood and varied between the temperatures 121° and 180° C. 

 at the center of the retort. Later the passage of more current 

 was allowed so as to afford the minimum temperature for dis- 

 tillation. At the beginning of the exothermic distillation the 

 main circuit was broken, and no current was allowed through 

 until the rise in temperature ceased and distillation lessened. 

 The rise in temperature during this period seldom exceeded 

 20° C. After passing this period of exothermic reaction, the 

 distillation dropped off rapidly and the application of current was 

 gradually increased up to a temperature of about 330° C. and 

 was increased rapidly to 550° C. In collecting the distillate, 

 graduated cylinders were used. 



Samples of pyroligneous distillate from each distillation were 

 analyzed for percentages of wood alcohol and acetic acid. Such 

 analyses taken on fast runs were compared with analyses of 

 products from controlled runs, and the results were tabulated 

 in averages. 



Table II. — Showing the average percentages of wood alcohol and acetic 

 acid obtained from a fast and from a slow distillation. 



Wood. 



Slow distillation. 



Fast distillation. 



Methyl 

 alcohol. 



Acetic 

 acid. 



Methyl 

 alcohol. 



Acetic 

 acid. 





0.91 



1.20 

 1.55 



0.74 

 1.61 

 1.36 

 0.82 

 2.12 

 1.71 

 1.84 

 1.01 



3.80 

 2.92 

 2.90 

 4.70 

 4.61 

 3.83 

 4.40 

 4.37 

 2.12 

 5.16 

 4.66 



6.31 



0.72 

 1.10 

 1.11 

 1.31 

 0.92 

 0.62 

 1.41 

 1.24 



1.56 

 1.42 

 1.17 

 1.00 



3.91 

 2.85 



5.18 

 4.25 

 3.62 

 4.42 

 4.77 

 2.51 

 4.84 

 4.27 

 4.50 

 6.16 









Yacal - 





Ipil 

















