METHOD OF FIR BARK PROCESSING Russian patent published in 1999 - IPC

FIELD: wood chemical processing. SUBSTANCE: invention relates to processing fir bark to obtain for oil, fir balsam, tannic substances and carbon sorbents. Method involves milling, extraction with nonpolar solvent, evaporation of extract. Then extract is separated for fir oil and fir balsam by vacuum distillation and bark residue is activated at 200-260 C under pressure 3-5 MPa for 30-60 s and then bark is extracted with an aqueous-alcoholic mixture. Tannic extract is isolated and remained bark is converted to carbon sorbents by oxidative pyrolysis at 600-800 C for 25-35 min in the presence of open-hearth slag. Method provides the complete utilization of fir bark. EFFECT: broadened assortment of forest-chemical products obtained, improved method of processing. 3 tbl, 1 dwg, 1 ex