YIELDS FROM DISTILLATION OF CERTAIN HARDWOODS. 



Table 1. — Sample data sheet. 



Shipment No. 197. 



Sample Nos. 21 and 22. 



January 14, 1913. 



Actual weight of charge 69.86 pounds. 



Dry weight of charge 63.10 pounds. 



Project No. 152.- 



Run No. 97. 



Birch slab wood. 



10 per cent to 14 per cent bark. 





Time. 



Temperature. 



Total 

 distil- 

 late. 







Tube 

 No. 1. 



Tube 

 No. 5. 



Remarks. 





January IS. 



"C. 



°C. 



20 



180 

 220 

 246 

 263 

 278 

 291 

 305 

 318 

 325 

 351 

 370 

 378 

 379 

 376 

 284 



50 



c. c. 



Retort charged; gas on one-half. 





January 14- 



234 

 280 

 303 

 312 

 317 

 322 

 329 

 336 

 342 

 342 

 344 

 341 

 339 

 337 

 282 



3,200 

 4,200 

 5, 700 

 6,700 

 7,700 

 8,700 

 9,700 

 10, 700 

 11, 700 

 12, 700 

 13, 200 

 13, 500 



Gas on full. 





























Gas off. 





















Maximum temperature. 











14,000 

 14, 200 







January 15. 











Total distillate= 32.S3 pounds. 



COLLECTION AND ANALYSIS OF PRODUCTS. 



A typical data sheet is shown in Table 1. The time and tempera- 

 tures were read as every liter or half liter of distillate was collected. 

 In a few distillations separate titrations for acetic acid were made 

 on the first several fractions of one-half liter or one liter each, but in 

 general all the distillate was mixed for analysis. 1 The distillate was 

 allowed to settle for at least 24 hours. At the end of that time the tar 

 and pyroligneous acid were separated by decantation, and the vol- 

 ume and weight of each determined. The charcoal was allowed to 

 cool in the retort over night, and was weighed after separation from 

 the "tar coke." Tar coke refers to the material occurring in the 

 retort that was clearly a residue from the distillation of tar. This 

 was weighed separately. The gas was computed by difference, and 

 no determination of its composition was made. 



PYROLIGNEOUS ACID. 



The pyroligneous acid was analyzed by the methods described by 

 Klar 2 for the determination of acetic acid, wood alcohol, and dis- 



1 The acetic acid in that part of the distillate (consisting usually of water) which came over before true 

 destructive distillation began amounted to from 8 to 10 per cent of the total acetic acid; the alcohol in the 

 same part amounted to about 1 per cent of the total alcohol. The volatile acids obtained at temperatures 

 below the point at which the wood begins to distill destructively, say 280° C, must have an origin ! l 

 ent from that of the acid obtained during the destructive distillation. It is probably formed by ac ti 



the water on the wood fiber at high temperatures similarly to the acid obtained by hydrolysis as re; 

 by Cross (Dissertation, Gottingen, 1910). 



2 Technologie der Holzverkohlung, p. 337. 



