14 WOOD TURPENTINE. 



constituents of rosin spirits, and the fractions boiling at from 250 

 to 400 C. consist of rosin oils contaminated with decomposition prod- 

 ucts from the wood substance. 



The alkali solution after separation from the crude oils contains 

 the wood creosote, tar, and other alkali-soluble bodies. The wood 

 creosote and tar acids may be separated by adding sulphuric acid in 

 excess, washing the separated material several times with water, 

 arid further refining, if desired, by distillation. (See Table 2, p. 60, 

 for analyses of pine oils and still residues.) 



EQUIPMENT FOB THE MANUFACTURE OF WOOD TURPENTINE. 



The equipment of a plant for the destructive distillation of resinous 

 woods would, of course, vary with its capacity, size and shape of 

 retort, and arrangement of the plant. Small retorts of about 1 

 cord capacity are most commonly used, and an approximate idea of 

 the kind and quantity of apparatus required for a plant distilling 

 12 cords per 24 hours is given by the following list: 



12 retorts, 1 cord each. 

 12 condensers. 



100 100-pound charcoal cans. 

 2 tar stills. 



1 turpentine refining still. 



2 or 3 settling vats for crude turpentine, crude pyroligneous acid, and free tar. 

 1 100-horsepower boiler. 



1 20-horsepower engine. 



Pumps for supplying water to condenser and handling turpentine, etc. 



Storage tanks for crude and refined products. 



Conveyers and copper piping. 



Suitable buildings for housing equipment. 



The yield of wood alcohol and acetic acid is less than half of that 

 obtained from hard woods, or about 4 gallons of alcohol and from 

 50 to 90 pounds of acetate of lime, and practically no effort is made 

 to recover either of these products. In case these are recovered, addi- 

 tional stills, tanks, and steam pans are required. 



The cost of such a plant varies greatly in accordance with the 

 quality and completeness of the equipment and with local labor and 

 other conditions. Reliable builders of such plants quote from $1,000 

 to $2,000 per day cord on the basis of a 10-cord plant, with propor- 

 tionately higher prices for smaller plants and lower prices for larger 

 plants. For the steam distillation of wood where only turpentine 

 and pine oils are recovered, a less elaborate equipment is required. 

 For a plant of 10 units, the following list gives an idea of the equip- 

 ment needed: 



10 retorts, 1 cord each. 

 10 condensers. 



2 150-horsepower boilers. 

 1 100-horsepower engine. 



