Recovery of Wood Preservatives from Wood Pyrolysis Tar by Solvent Extraction

Abstract

Wood pyrolysis tar, which was discharged as a waste by-product in the production of charcoal from larch, was separated into several fractions by solvent extraction using tetrahydrofuran, benzene, and aqueous alkali. The fractions obtained were physicochemically characterized and examined for wood preservative effectiveness. This separation method compared favorably with fractional distillation in the effectiveness and safety of wood preserving components recovered, as well as the operational economy. Such a selective, safe, and inexpensive recovery of wood preservatives will be thus a promising utilization route of waste wood tar.