A method of producing dimethyl succinate

A technology of dimethyl succinate and its production method, which is applied in the preparation of carboxylic acid esters, chemical instruments and methods, and the preparation of organic compounds, and can solve the problems of highly toxic dimethyl sulfate, waste of materials, and difficulty in removing water in time and other problems, to achieve the effect of simplified process, short process, simple equipment, small quantity, and stable product quality

Inactive Publication Date: 2017-06-06
上海唯稳实业有限公司 +5
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Add 110Kg of potassium hydrogensulfate monohydrate, 366Kg of succinic acid, and 412Kg of methanol into an esterification kettle with an internal reflux condenser, and perform an esterification reaction under normal pressure internal reflux for 5 hours, and the internal temperature of the kettle is stabilized at 82°C to stop the reaction. Obtain crude ester, after cooling and standing still, suction filter to rectifying still;

[0032] Recover methanol under normal pressure, distill water under slight negative pressure; vacuum rectify to obtain the finished product dimethyl succinate;

[0033] Monomethyl succinate and a small amount of entrained potassium bisulfate stay in the rectifying still and send back to the esterification still; reclaim the methanol in the methanol aqueous solution and recycle;

[0034] When the obtained crude ester content≤80%, use denatured methanol to activate the catalyst; the activation method includes the following steps:

[0035] Add denat...

Embodiment 2

[0039] Add 110Kg of potassium hydrogensulfate monohydrate, 366Kg of succinic acid, and 412Kg of methanol into an esterification kettle with an internal reflux condenser, and react for 3.5 hours under a pressure of 0.20Mpa. The temperature in the kettle is stabilized at 99.7°C, and the reaction is stopped to obtain Crude ester, after cooling and standing still, suction filter to rectifying still;

[0040] Methanol is recovered under normal pressure, water is distilled out under slight negative pressure; the finished product dimethyl succinate is obtained through vacuum rectification.

[0041] Monomethyl succinate and a small amount of entrained potassium bisulfate remain in the rectifying still and are sent back to the esterification still;

[0042] Recover the methanol in the methanol aqueous solution and recycle it;

[0043] When the obtained crude ester content≤80%, use denatured methanol to activate the catalyst; the activation method includes the following steps:

[0044...

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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...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/08C07C69/40
CPCC07C67/08
Inventor 高云鹤孙松良董绍天孙猛王俊俊
Owner 上海唯稳实业有限公司
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