Production method of dimethyl maleate

Abstract

The invention provides a production method of dimethyl maleate, and in particular relates to a method used for producing the dimethyl maleate by enabling mixed liquid, which is obtained by using dimethyl maleate as a solvent to absorb maleic anhydride in maleic anhydride-containing mixed gas and is taken as a raw material, and methanol to be subjected to an esterification reaction. The production method comprises the following steps: enabling the maleic anhydride-containing mixed gas to be subjected to heat exchange and preliminary cooling, and then enabling the maleic anhydride-containing mixed gas to enter the bottom of an absorption tower and be in counter-current contact with the dimethyl maleate sprayed from the top of the tower so as to obtain absorption liquid; filling an esterification tower with solid acid esterification catalyst filler, pumping the absorption liquid from the top of the esterification tower, and enabling the pumped absorption liquid and the methanol at the bottom of the esterification tower to be subjected to a contact type reaction; obtaining a dimethyl maleate crude product at the bottom of the tower, distilling to obtain the dimethyl maleate product, and returning part of the dimethyl maleate product for absorbing the maleic anhydride in a spraying way; carrying out distillation and separation on water-containing methanol steam on the top of the tower to obtain methanol and water, and returning the methanol for the esterification reaction.

Description

technical field [0001] The invention provides a kind of production method of dimethyl maleate, specifically a kind of mixed liquid that takes dimethyl maleate as a solvent and absorbs the maleic anhydride in the mixed gas containing maleic anhydride to obtain as raw material, and The method that methyl alcohol carries out esterification reaction produces dimethyl maleate. Background technique [0002] Dimethyl maleate is commonly known as dimethyl maleate (DMM), a colorless viscous liquid with a molecular formula of C 6 h 8 o 4 , boiling point (101.3kPa) 200.4°C, melting point -19.0°C, relative density 1.146. Dimethyl maleate is an important organic chemical raw material, used as a plasticizer, a preservative for fatty oils and a raw material for organic synthesis. Dimethyl maleate is used to produce 1,4-butanediol, tetrahydrofuran, γ-butyrolactone, dimethyl succinate, etc. through different catalytic hydrogenation processes, 1,4-butanediol and succinate di Methyl ester...

AI Technical Summary

Problems solved by technology

The traditional production method is to use maleic anhydride as raw material, and carry out esterification reaction with methanol under the catalysis of sulfuric acid. Although this production process has high catalytic activity and low price of catalyst sulfuric acid, there are many side reactions and many products are easily isomerized into fuma Disadvantages such as dimethyl ester, severe equipment corrosion, and complicated follow-up treatment

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