METHOD FOR SEPARATING DIMETHYLAMIDE COMPOUND AND CARBOXYLIC ACID BY DISTILLATION AND APPARATUS THEREFOR

摘要

PROBLEM TO BE SOLVED: To solve problems that water is produced and mixed in purified dimethylamide, and to provide the high-purity dimethylamide containing slight impurities when quinolines are added to a maximum azeotropic composition of a mixture liquid of a carboxylic acid and the dimethylamide to separate the carboxylic acid and dimethylamide by distillation. SOLUTION: The purified dimethylamide is taken out from a position at the intermediate height of a dimethylamide purifying distillation column in the distillation column. Thereby, the water produced in the distillation column as a minor impurity can be enriched to an overhead distillate and separated. As a result, the high-purity dimethylamide containing the slight impurities is obtained. COPYRIGHT: (C)2004,JPO