Process for preparing unsaturated carboxylic acid esters and apparatus

Abstract

The present invention relates to a process for continuously preparing unsaturated carboxylic acid esters by esterifying an (aliphatic) alcohol having 1 to 8 carbon atoms with an unsaturated carboxylic acid in the presence of a cation exchange resin catalyst, characterized in that the process is conducted by continuously circulating said reactants in contact with said catalyst from the top to the bottom through a reactor which is composed in the form of a fixed bed divided into 1 to 10 steps wherein each step comprises a catalyst bed, a filter and a air inlet, and has a thermal insulating outer wall, supplying a vaporizing heat for extraction of water, which is produced during the reaction, through a heat exchanger outside the reactor, circulating the reactants between the reactor and the heat exchanger by means of a circulating pump, contacting an azeotropic mixture of water vaporized by the heat exchanger and an alcohol with an alcohol circulating in a column tower or a raw alcohol supplied from an alcohol inlet located on the top of the column tower to recycle the high boiling component into the reactor and, at the same time, to transfer the light component to the upper part of the column in which the light component is condensed, separating the condensate into an organic layer and water in a decanter, and then recycling the organic layer into the reactor and removing the water produced during the reaction, and a novel apparatus for carrying out this process.