Process for preparing carboxylic esters by reactive distillation

Abstract

In a process for preparing carboxylic esters by transesterification, a first feed stream comprising a first carboxylic ester, e.g. methyl formate, is introduced laterally into a reaction column at least one first feed point located between top and bottom of the reaction column and a second feed stream comprising a first alcohol, e.g. ethanol, is introduced laterally into the reaction column at a second feed point located above the first feed point and 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 point located above the second feed point. At the bottom of the reaction column, a bottom fraction comprising the second alcohol and unreacted first alcohol is taken off. 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 comprising unreacted first carboxylic ester and the fraction comprising unreacted first carboxylic ester is at least partly recirculated to the reaction zone.

Dependencies are inferred from the claim text.