PROCESS FOR PREPARING CARBOXYLIC ESTERS BY REACTIVE DISTILLATION

摘要

In a process for preparing carboxylic esters by transesterification, a first feed stream comprising a first carboxylic ester, e.g. methyl formate, is introduced at the side into a reaction column at a first inlet located between the top and the bottom of the reaction column and a second feed stream comprising a first alcohol, e.g. ethanol, is introduced at the side into the reaction column at a second inlet located above the first inlet and the feed streams are reacted in a reaction zone of the reaction column to form a second carboxylic ester and a second alcohol. The first alcohol has a higher molecular weight than the second alcohol. A product fraction comprising the second carboxylic ester and unreacted first carboxylic ester is taken off at an offtake located above the second inlet. A bottom fraction comprising the second alcohol and unreacted first alcohol is taken off at the bottom of the reaction column. The product fraction is separated by distillation at a pressure which is different from the pressure in the reaction column into second carboxylic ester and a fraction containing unreacted first carboxylic ester and the fraction containing unreacted first carboxylic ester is at least partly recirculated to the reaction zone.