CHAPTER VIII 

 HARDWOOD DISTILLATION * 



HISTORY 



Introduction. 



The heating or carbonizing of wood for the purpose of manufacturing 

 charcoal has been in practice as long as history is recorded. It is believed 

 that it is as old as civilization itself. In the manufacture of charcoal by 

 the old process, the wood is heated to such temperatures that it is 

 carbonized while the gases that pass off in the form of dense, heavy, black 

 smoke have given rise to the modern processes of distilling wood. 



Altogether two distinct branches of the industry have been developed 

 in this country. The most important branch is devoted to the utilization 

 of the denser and heavier hardwoods and seeks the recovery of the follow- 

 ing commercial products wood alcohol, acetate of lime, and charcoal. 

 In addition the minor products are wood tar and wood gas, both of which 

 are at the present time usually utilized as fuel in the heating process. 

 Only those hardwoods that are comparatively free from an excessive 

 content of gums, tannins, resins, etc., are desirable. The so-called 

 Northern hardwoods, such as maple, birch and beech, are considered 

 the most desirable. Hickory and oak are also considered of almost equal 

 value. 



The other branch of the wood-distillation industry requires resinous 

 woods, and the objective products are, on the other hand, turpentine, tar, 

 wood oils, and charcoal. The southern longleaf pine is the best wood 

 for this kind of distillation and, up to the present time, has been prac- 

 tically the only one used for this purpose. 



Early Practices. 



The first record of the distillation of wood on a commercial scale in 

 this country was in 1830, when James Ward began the manufacture of 

 pyroligneous acid at North Adams, Mass. This is the raw liquor 



1 This chapter is largely taken from The Hardwood Distillation Industry in New York, by 

 the author, bulletin of the New York State College of Forestry, Syracuse, New York, 1916. 



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