Method for synthesizing and preparing glyphosate with glycine method

Abstract

The invention relates to a method for synthesizing and preparing glyphosate with a glycine method. Paraformaldehyde, glycine and dimethyl phosphite are used as raw materials for reaction, methanol is used as a solvent, and alcohol amine is used as a catalyst to carry out glyphosate condensation synthesis reaction; after the processes of the condensation reaction are finished, hydrochloric acid orhydrogen chloride (HCl) gas is introduced in a condensation solution to form ethanolamine hydrochloride; after the ethanolamine hydrochloride is filtrated and separated, the hydrochloric acid is continuously added in the condensation solution for hydrolysis to obtain the glyphosate; after dealcoholization, alkali is added to adjust pH, the glyphosate is precipitated from cooling crystals, and washed and dried to obtain finished products. Mother liquid is condensed to prepare a glyphosate aqueous solution. The alcohol amine can be triethanolamine, diethanol amine, monoethanolamine, carbinolamine, dimethylaminoethanol and the like, and in particular to the triethanolamine. The mole ratio of hydrogen chloride gas introducing amount to the added related alcohol amine is 1:(1-1.5). In the invention, triethanolamine Hydrochloride can be recovered through ordinary filtration and separation, the yield of the triethanolamine Hydrochloride can reach 95%, and the content of the triethanolamine Hydrochloride can reach more than 99%; and the recovered triethanolamine Hydrochloride can be neutralized with NaOH to transform into the triethanolamine as raw materials for production in repeated use, and can be used as products for sale.

Description

technical field [0001] The invention relates to a glyphosate synthesis preparation method by a glycine method, in particular to a preparation method using novel catalyst technology in the glyphosate synthesis process. technical background [0002] Glyphosate is a high-efficiency and destructive chemical herbicide, and it is the most widely used chemical herbicide in the world. The current annual use in the world is about 800,000 tons, and the annual growth rate is more than 20%. [0003] At present, there are two kinds of glyphosate production routes for industrialization in China. One is the alkyl ester method with glycine as the main raw material; the other is the IDA method with diethanolamine and iminodiacetonitrile as the main raw materials. Domestic glyphosate production Mainly based on the alkyl ester method. [0004] The alkyl ester method has the advantages of mature and stable production process, less reaction process, short cycle, relatively low investment cost, ...

AI Technical Summary

Problems solved by technology

At present, all alkyl ester methods use triethylamine as a synthesis catalyst, put glycine, paraformaldehyde, triethylamine and methanol into the reactor for depolymerization, then add dimethyl phosphite for synthesis, and add hydrochloric acid after the polycondensation is completed Carry out hydrolysis to obtain glyphosate, add alkali to adjust pH, make glyphosate precipitate, catalyst triethylamine is converted into triethylamine hydrochloride, need to continue to add a large amount of liquid caustic soda to glyphosate acid mother liquor to neutralize triethylamine Hydrochloride, generate triethylamine and sodium salt and produce a large amount of glyphosate mother liquor (alkali mother liquor), separate triethylamine and reuse in glyphosate production, glyphosate mother liquor is concentrated, produces a large amount of industrial salt, these Salt has limited use due to various phosphorus-containing impurities

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