PURPOSE: To separate and recover 3,5-xylenol from an azeotropic mixture in high purity and good efficiency by adding a tar base having boiling point being in a specific range as an azeotropic solvent to xylenol oil consisting essentially of xylenol isomers and distilling the-mixture under reduced pressure.
CONSTITUTION: A tar base selected from quinolines or isoquinolines having 235-270 C boiling point range or tar base oil containing tar base having the above-mentioned boiling point range is added to xylenol oil which is tar acid mixture consisting essentially of xylenol isomer separated from tar oil obtained by distillation of coal based oil, by operation of distillation, alkali extraction, etc., and the mixture is distilled under reduced pressure. The resulted high- boiling point azeotropic mixture is subjected to extraction treatment by an alkali water solution or distillation at ordinary pressure of about 760-600Torr to recover highpurity 3,5-xylenol.
YOSHINAGA SHOZO
MURAKAMI KOYO
