PURPOSE: To hydrolyze methyl ester of a carboxylic acid into a carboxylic acid and methanol, and recirculate and use the carboxylic acid for the acid exchange reaction, by subjecting methyl acetate and a carboxylic acid having a specific number of carbon atoms to the acid exchange to obtain the methyl ester of the carboxylic acid and acetic acid.
CONSTITUTION: Methyl acetate is subjected to the acid exchange with a ≥4C carboxylic acid in the presence of an acidic catalyst, preferably a strongly acidic type ion exchange resin. In the process, butyric acid is used as the above-mentioned carboxylic acid, and the acid exchange reaction is first carried out in the first reactor 6 to introduce the resultant effluent into the first distillation column 7. An azeotropic mixture of the methyl acetate with water, etc. is circulated from the top of the first distillation column 7 through the first reactor 6, and methyl butyrate, etc. is introduced from the bottom of the column 7 into the second distrillation column 8. An azeotropic mixture of the methyl butyrate with water is introduced from the top of the second distillation column 8 into the second reactor 10 and passed through the bottom to the third distillation column 9 to give the acetic acid from the top of the third distillation column 9. The hydrolysis reaction is carried out in the second reactor 10 to give methanol from the top of the fourth distillation column 11, and an organic layer from a decanter 12 is distilled in the fifth distillation column 13 to circulate the resultant butyric acid from the bottom of the fifth distillation column 13.
FUCHIGAMI YOSHIO
KIKUCHI KOUICHI
