Production of carboxylic acid esters by stripping with alcohol vapor

摘要

The invention relates to a method for producing carboxylic acid esters by reacting a reaction mixture, comprising a carboxylic acid and/or a carboxylic acid anhydride, and an alcohol in a reaction system having one or more reactors, wherein reaction water is distilled off as an alcohol/water azeotrope with the exhaust vapor. In addition, the reaction mixture is treated with superheated alcohol vapor. The method allows the production of esters having a low acid number.

主权项

1. A process for preparing carboxylic esters by reaction of a reaction mixture comprising a carboxylic acid and/or a carboxylic anhydride and an alcohol in the presence of an esterification catalyst selected from group consisting of alkoxides, carboxylates and chelate compounds of titanium, zirconium, tin, aluminum and zinc, in a reaction system comprising one or more stirred tank reactors, with water of reaction being distilled off as alcohol-water azeotrope with the vapor, where the vapor from at least one reactor is at least partly condensed, the condensate is separated into an aqueous phase and an alcohol phase and the alcohol phase is at least partly recirculated to the reaction system, wherein the reaction mixture is treated with superheated alcohol vapor, wherein the alcohol vapor is introduced below the surface of the liquid reaction mixture and the alcohol vapor bubbles through the reaction mixture, and wherein the temperature of the superheated alcohol vapor is at least 20° C. higher than the dew point.