A method of producing dimethyl succinate

Abstract

A method of producing dimethyl succinate is disclosed. The method includes steps of adding a catalyst, succinic acid and methanol into an esterification kettle provided with an internal reflux condenser, performing a reflux esterification reaction under a pressure ranging from atmospheric pressure to 0.20 MPa until the temperature in the kettle is stable to obtain a crude ester, allowing the crude ester to stand, cooling the crude ester, subjecting the crude ester to suction filtration, transferring a suction filtration product to a rectification column, recovering a methanol-water solution under atmospheric pressure by adopting a rectification process, removing water through distillation in vacuum, and performing vacuum rectification to obtain the dimethyl succinate. The catalyst is potassium bisulfate monohydrate. The method effectively achieves reuse of the catalyst and raw materials. The total yield of a finished product is not less than 97%. Energy consumption and material consumption are low. The service cycle of the catalyst is prolonged.

Description

technical field [0001] The present invention relates to the production method of dimethyl succinate (dimethyl succinate). Background technique [0002] Dimethyl succinate is an important synthetic fragrance and organic solvent, and is also the main raw material for the synthesis of photosensitive polymers and advanced organic pigments. [0003] The process of large-scale industrial production of dimethyl succinate is to first catalyze esterification of maleic anhydride and methanol, and then catalytic hydrogenation to obtain a mixture of dimethyl succinate and succinic acid. [0004] The method of intermittent mass production of dimethyl succinate is to adopt the traditional esterification process: that is to use succinic acid and methanol as raw materials, catalytic synthesis under normal pressure under acidic conditions: [0005] HOOC (CH 2 ) 2 COOH+2CH 3 OH→CH 3 OOC (CH 2 ) 2 COOCH 3 +2H 2 O(I) [0006] HOOC (CH 2 ) 2 COOH+CH 3 OH→CH 3 OOC (CH 2 ) 2 COOH+H...

AI Technical Summary

Problems solved by technology

[0008] Sulfuric acid is highly corrosive and will generate highly toxic dimethyl sulfate; large-pore strong acid resin is expensive

These catalysts have the following disadvantages: 1. The service life is short, some only once, and soon become waste; 2. The esterified product often needs to be washed and washed to form process wastewater; 3. Methanol and water cannot form azeotrope, and ester The water generated in the chemical process is difficult to remove in time, and the content of monomethyl succinate generated by the reaction of the above formula (II) will be very high, and will become waste in the washing and washing process, resulting in a great waste of materials; 4. Since the boiling point of methanol is much lower than that of water, the vapor pressure of methanol is much higher than that of water. If the methanol cycle distillation is used to take away the water, the energy consumption will be greatly increased