A kind of continuous production process and device of amino acid methyl ester

Abstract

The invention discloses a continuous production process of amino acid methyl ester, comprising the following steps: (1) a mixed liquid of amino acid, sulfuric acid and methanol enters an esterification tower from the top to carry out esterification reaction, obtains an esterification reaction liquid from the bottom of the tower, and obtains an esterification reaction liquid from the bottom of the tower; The top of the tower obtains water-containing methanol vapor; (2) the mother liquor obtained after the product is extracted from the esterification reaction solution is concentrated in the concentration kettle to obtain a concentrated solution and methanol-containing water vapor; (3) the water-containing methanol vapor obtained in step (1) is obtained from The middle part enters the rectifying tower, and the methanol-containing steam obtained in step (2) enters the rectifying tower from the bottom, obtains anhydrous methanol vapor from the top of the rectifying tower, and obtains condensed water at the bottom of the tower; (4) from step ( 3) Part of the obtained anhydrous methanol vapor is returned to the top of the rectification tower for reflux, and part of it enters the bottom of the esterification tower to carry out esterification reaction. The continuous production process reduces a large number of heating and condensation processes, and greatly improves the utilization efficiency of energy.

Description

technical field [0001] The invention belongs to the field of chemical production, and specifically relates to a continuous production process of amino acid methyl ester and a device used therefor. Background technique [0002] Amino acid methyl ester is an important chemical raw material, which is often used in the synthesis of drugs or intermediates. Its preparation is generally obtained by the reaction of amino acid and methanol under the action of acid. There are two specific synthesis methods. [0003] The first method for synthesizing amino acid methyl esters is: the amino acid reacts with methanol in the presence of thionyl chloride, and the disadvantage is that hydrogen chloride and sulfur dioxide are released, and the equipment has high requirements for anticorrosion and is troublesome to handle. [0004] The second synthesis method is that amino acid and methyl alcohol react in the presence of sulfuric acid, for example: Chinese patent application with publication n...

AI Technical Summary

Problems solved by technology

This method has a high yield, but the disadvantage is that the amount of anhydrous methanol is relatively large and has high requirements for moisture. The methanol directly distilled from the reaction system has a high water content, and it needs to undergo strict rectification to fully remove the moisture before it can be applied mechanically; in addition, Because sulfuric acid used as a catalyst in the reaction process will react with methanol to generate monomethyl sulfate, the mother liquor after recycling amino acid methyl ester contains a large amount of monomethyl sulfate salt, and this part of the consumed methanol cannot be recovered by simple distillation, resulting in methanol The loss is large

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