Method for preparing dimethyl succinate

Abstract

The invention discloses a method for preparing dimethyl succinate. The method comprises two reaction processes of esterification and hydrogenation and the reaction processes are as follows: (1) after pre-esterification reaction, maleic anhydride-methanol solution enters a catalytic distillation tower from the upper rectifying section of the tower, methanol enters the tower from the lower stripping section of the catalytic distillation tower, the reaction section is filled with solid acid catalyst, the two material flows perform countercurrent contact on the surface of the catalyst to perform esterification reaction and synthetize dimethyl maleate; and (2) dimethyl maleate and hydrogen are placed in a fixed bed reactor to perform hydrogenation reaction and generate the dimethyl succinate product in the presence of hydrogenation catalyst under a certain reaction condition. The method of the invention has the advantages of high raw material conversion rate and good product selectivity; and the process flow is simple, the energy consumption is low, no pollution can be caused and the scale production of dimethyl succinate can be realized.

Description

technical field [0001] The invention relates to a method for preparing dimethyl succinate, in particular to a method for preparing dimethyl succinate from maleic anhydride through esterification and hydrogenation. Background technique [0002] Dimethyl succinate (also known as dimethyl succinate), is a colorless or light yellow liquid (at room temperature), widely used as an environmentally friendly high boiling point solvent. Dimethyl succinate is also an important chemical intermediate, which is widely used in food, fragrance, medicine, paint, rubber, plastic and other industries to synthesize light stabilizers, high-grade paints, fungicides, and pharmaceutical intermediates. [0003] The traditional dimethyl succinate process technology is succinic acid and methanol batch catalyzed esterification synthesis, and the catalyst is commonly used concentrated sulfuric acid. Because concentrated sulfuric acid corrodes equipment, it has the disadvantages of oxidation, many side...

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Problems solved by technology

However, the method uses liquid acid in the esterification process to easily cause equipment corrosion, and the catalyst and the product need to be separated repeatedly and the product loss is large, which not only consumes high energy, but also pollutes the environment; in addition, the dimethyl maleate electrolytic reduction method The current efficiency and conversion rate of raw materials in the synthesis of dimethyl succinate are not high, the energy consumption and material consumption of the whole process are relatively large, and the large floor area is not conducive to large-scale production