Preparation method of glycine

Abstract

The invention relates to a preparation method of glycine, which belongs to the technical field of chemical production and comprises the following five steps: preparing an ammonium chloroacetate solution, preparing a product glycine solution, preparing a glycine finished product, recovering to obtain an organic amine hydrochloride crystal solid and a filtrate containing urotropine, recovering an organic amine solution and preparing an ammonium chloride solid. The preparation method disclosed by the invention is simple and environment-friendly, the prepared glycine product is high in purity, and meanwhile, an industrial-grade ammonia chloride product can be obtained through co-production; the organic amine, the methanol and the catalyst urotropine used in the preparation process can be recycled, so that the production cost is saved, and the purpose of zero emission is achieved.

Description

technical field [0001] The invention relates to a preparation method of glycine, which belongs to the technical field of chemical production. Background technique [0002] Glycine, also known as aminoacetic acid, is a non-essential amino acid. As an important fine chemical product, amino acid has important uses in food, medicine, agriculture, industry, etc. In terms of food, glycine can be used as a nutritional supplement, as a flavoring agent, and can also play a seasoning role. At the same time, it has a certain inhibitory effect on the reproduction of Bacillus subtilis and Escherichia coli; Combination with aspirin can reduce the irritation to the stomach, and can also treat hyperprolinemia in children; in agriculture, glycine is an intermediate of synthetic pyrethroid insecticides, glycine ethyl ester hydrochloride, synthetic pyrethroids It is an important raw material for the fungicide iprodione and the herbicide solid glyphosate, and can also be used as an additive an...

AI Technical Summary

Problems solved by technology

However, this method has many disadvantages. The yield of glycine is only about 85%. The production of one ton of glycine requires rectification of about 13 cubic meters of methanol solution, which requires high energy and equipment consumption. At the same time, the production of one ton of glycine requires 150 kilograms of urethane Tropin cannot be recycled, and ammonium chloride needs to be obtained by evaporating and concentrating solvent water, which consumes a lot of energy, and the final red wastewater needs to be further treated, otherwise it will cause great pollution to the environment

[0004] Patent CN1080632A proposes an improved synthesis method of glycine, using chloroacetic acid and ammonia as raw materials, using organic amines such as triethylamine, tripropylamine and tributylamine as acid-binding agents to obtain glycine with higher purity, but catalysts and organic amines have no be effectively reused

[0005] In patent CN102030669A, in the presence of a catalyst, chloroacetic acid and ammonia are used as raw materials, and organic amines are used as acidic agents to separate glycine and ammonium chloride. However, ammonia is passed through the mother liquor after separating glycine to obtain ammonium chloride. Difficult to control, unable to fully recover triethylamine, and easy to obtain mixed crystals of glycine and ammonium chloride, need further treatment

What reclaimed is the methanol mother liquor of triethylamine, if the reactant is chloroacetic acid during recycling, triethylamine and chloroacetic acid react to generate by-products, yield and purity decline; if the reactant is ammonium chloroacetate, it needs to be processed to obtain Ammonium chloroacetate or buy, add cost