JP2985003B

PROBLEM TO BE SOLVED: To efficiently collect and separate high purity bamboo vinegar suitable for vinegar and other constituents from material including bamboo pyrolysis material. SOLUTION: The pH of the bamboo pyrolysis liquid 1 is previously adjusted to 9-11 before manufacturing bamboo vinegar from the pyrolysis liquid by distillation. The hydrophobic tar is removed by aerating with carbon dioxide gas until the liquid reaches to neutral pH 6.5-7. The stock solution is evaporated and concentrated until the half of the stock solution in the first distillation process to remove low boiling point organic compounds, the liquid is evaporated to dryness in the second distillation process after adjusting the pH of the distilling solution to acidic of pH 2.5-3. In this way the bamboo vinegar fraction mainly comprising acetic acid and the distillation residue are separated and collected. The solvent soluble parts of the distillation residue are obtained from the residue by adding an organic solvent, extracting the solvent soluble part and collecting.