Method for preparing DL-methionine

Abstract

Disclose is a device for preparing DL-methionine, comprising a reaction unit and a crystallization separation unit. The reaction unit is a horizontal reactor. A liquid outlet of the horizontal reactor is in communication with an inlet of a circulating pump, and an outlet of the circulating pump is separately in communication with a liquid inlet of the horizontal reactor and a liquid inlet of the crystallization separation unit. After being in communication, the circulating pump and the horizontal reactor form a circulating system whose total volume is equal to 3-5 times the feed volume. Also disclosed is a method for preparing DL-methionine by using the foregoing device, comprising: continuously feeding an aqueous solution of DL-methionine salt and concentrated sulfuric acid into the horizontal reactor for neutral reaction; dividing the liquid discharged from the liquid outlet of the horizontal reactor into two parts through the circulating pump; and returning one part of the liquid to the horizontal reactor to be forcedly circulated in the volume equal to 3-5 times the feed volume, and introducing the other part of the liquid to the crystallization separation unit to precipitate DL-methionine crystals to obtain DL-methionine. By using the device and method, a great deal of heat released through the neutral reaction is evenly dissipated, and the reaction retention time is prolonged, which is beneficial to complete reaction; large-scale continuous industrial production is realized, and byproducts are reduced as much as possible.

Description

technical field [0001] The invention belongs to the field of chemical industry and relates to an improved preparation device and method of chemical products. Background technique [0002] Methionine, also known as methionine, is one of the basic units of protein. It is the only amino acid containing sulfur among the essential amino acids. In addition to participating in the transfer of methyl groups in animals, the metabolism of phosphorus and the synthesis of adrenaline, choline, and creatine In addition, it is also a raw material for the synthesis of protein and cystine. Methionine is widely used in the fields of medicine, food, feed and cosmetics, among which the largest amount is used as a feed additive. However, at present, almost all methionine in my country depends on imports, and the domestic production is very low, which is far from meeting the demand. [0003] One of the preparation methods of DL-methionine is the hydantoin method, which is to react 3-methylthiopr...

AI Technical Summary

Problems solved by technology

Many foreign methionine manufacturers have conducted a lot of research on the specific process and equipment of the above-mentioned preparation route and applied for many patents. Considering production and other aspects, the above processes and equipment still need to be improved

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