Method for recovering triethylamine hydrochloride from glyphosate reaction liquid produced by glycine process

Abstract

The invention discloses a method for recovering triethylamine hydrochloride from glyphosate reaction liquid produced by a glycine process. The method comprises the following steps: S1, removing waterand hydrochloric acid from the glyphosate reaction liquid to obtain a solid mixture; S2, adding a solvent into the solid mixture, conducting heating, and carrying out phase transfer to obtain a solvent phase, wherein a solid phase is also obtained in the step and is used for synthesizing glyphosate; S3, cooling the solvent phase to obtain a crude triethylamine hydrochloride product; and S4, centrifuging the obtained crude triethylamine hydrochloride product, and carrying out spray drying to obtain a finished triethylamine hydrochloride product. According to the invention, on the premise of ensuring the content of triethylamine hydrochloride in the finished triethylamine hydrochloride product, the yield of triethylamine hydrochloride is increased.

Description

technical field [0001] The invention relates to a method for recovering triethylamine hydrochloride from the glyphosate reaction solution of the glycine method. Background technique [0002] At present, glyphosate is the herbicide with the largest production and sales volume, and China's production capacity has reached more than 700,000 tons per year. The main synthesis route of glyphosate in China is the glycine method. During the production process, a large amount of mother liquor is produced. The main components of the mother liquor are glyphosate, phosphorous acid, sodium chloride, glyphosate, glycine and other organic substances. Every ton of glyphosate produces 5 tons of high-salt, high-phosphorus, high-organic-content wastewater. There are various treatment methods for the above-mentioned wastewater at home and abroad, such as membrane recovery, incineration, catalytic wet oxidation, precipitation, extraction and adsorption, or a combination of the above methods. Ho...

AI Technical Summary

Problems solved by technology

Moreover, because the reaction water in the synthesis reaction process will hydrolyze dimethyl phosphite to generate phosphorous acid, it will also cause the yield of dimethyl phosphite to decline.

[0005] As a catalyst, triethylamine can react with hydrochloric acid to generate triethylamine hydrochloride. Due to the existence of triethylamine hydrochloride, the solute content in the glyphosate reaction solution is increased, the specific gravity of the reaction solution increases, and the viscosity increases, making grass The crystallization environment of glyphosate becomes worse, which affects the yield of glyphosate

The recovery of triethylamine in the later stage of the original method and the addition of excessive sodium hydroxide will cause part of the glyphosate to form glyphosate sodium salt, which is also not conducive to the recovery of triethylamine hydrochloride.