Light oils Turpentine Heavy oil Tar Charcoal 



6 gallons 6 gallons 16 gallons 48 gallons 35 bushels 



Various processes in which the retort temperature 

 is controlled, as in the bath process and the processes 

 of Gautier, Pritchard, and others, have been proposed 

 and several put in operation for a time on either the 

 commercial or large experimental scale. They offer 

 advantages in the way of better yields and quality 

 of turpentine, but these gains are so nearly offset by 

 higher fuel costs and higher maintenance charges 

 that the commercial superiority of these more com- 

 plicated processes has yet to be demonstrated. 



Ten years ago recovery of turpentine from com- 

 minuted waste by steam distillation was practiced in 

 many plants, the steam being blown through the mass 

 of chips either upward or downward and carrying the 

 volatile oils with it to the condenser. The decline in 

 the price of turpentine in 1907 and 1908 proved so 

 severe a blow to the industry that it is to-day prac- 

 tically wiped out. 



The well known Yaryan process added to the steam 

 distillation method the subsequent step of extracting 

 the chips with a volatile solvent from which the dis- 

 solved rosin could later be recovered. Several plants 

 of large capacity were operated successfully until in 

 1913 the failure of the American Naval Stores Co. 

 caused a heavy drop in the price of rosin which was 

 followed by the failure of the company operating the 

 Yaryan process. A contributory cause may well 

 have been the large losses of solvent incident to the 

 process. 



Several methods have been proposed for the re- 

 covery of turpentine, pine oil and rosin from yellow 

 pine wastes by the action of water solutions of alkali 

 but none are thought to be operating commercially. 

 They depend upon the fact that the wood is only 

 slightly attacked by the dilute alkali in which the 

 rosin is readily soluble. Nevertheless, some wood 

 is dissolved and the difficulty of separating this so- 

 called "humus" from the rosin has prevented the 

 introduction of processes of this type. The difficulty 

 has been overcome in a simple and ingenious way 

 by Whitaker and Bates, who salt out the rosin soap 

 by increasing, after the initial treatment of the wood, 

 the concentration of the alkaline solution to 3.5 

 per cent free alkali. The treated chips are then avail- 

 able as a raw material for papermaking. 



When the real work of wood waste utilization has 

 (8) 



