| 摘要 |
PURPOSE:To purify tar acids at a high speed, by adding an alkali metal compd. to tar acids, bringing the mixture into contact with an oxygen-contg. gas to oxidize sulfur compds. contained therein and then carrying out vacuum distillation. CONSTITUTION:In a method for purifying tar acids comprising bringing a tar acid such as phenol, o-, m- or p-cresol or xylenol or a mixture thereof obtd. by distilling coal-tar tar acids, into contact with an oxygen-contg. gas such as air to oxidize sulfur compds. contained therein and carrying out vacuum distillation, an alkali metal salt, an alkali metal hydroxide or an alkali metal alkoxide is added to the tar acid or the mixture prior to bring the tar acids into contact with the oxygen-contg. gas, whereby the rate of oxidation of the sulfur compds. can be greatly increased and the contact time thereof with the oxygen-contg. gas can be geately shortened.
|
