Purification method for glufosinate-ammonium

Abstract

The invention relates to a purification method for glufosinate-ammonium. The method comprises the following steps that a glufosinate-ammonium hydrochloride crude product is dissolved into a solvent, then, alkaline is added to be subjected to a reaction, the pH value is adjusted to be 7-10, reduced pressure distillation is performed to remove some solvent, then filtering is performed to remove ammonium chloride and other undissolved substances; acid is added into the reaction solution to be subjected to a reaction, the pH value is adjusted to be 1-4.5, and then filtering and drying are performed to obtain glufosinate-ammonium acid; the glufosinate-ammonium acid is dissolved into the solvent, then, ammonia gas is introduced to be subjected to a salt forming reaction, glufosinate-ammonium solid is separated out, and filtering and drying are performed to obtain high-purity glufosinate-ammonium. According to the purification technology, fatty amine hard to remove and high-risk ethylene oxide and epoxypropane are prevented from being used, the steps are simple, the obtained glufosinate-ammonium is low in inorganic salt content and high in purity, yield and safety, water or alcohol is used as the solvent in the technological process, ammonium hydroxide and inorganic base are used for being subjected to a neutral reaction, the glufosinate-ammonium conforms to the environment-friendly and economical principle, and the good industrial prospect is achieved.

Description

technical field [0001] The invention belongs to a purification method of chemicals, in particular to a purification method of glufosinate-ammonium. Background technique [0002] Glufosinate-ammonium is a biocidal contact herbicide with the characteristics of high efficiency, low toxicity, low residue and safety. Its quick-acting property is between paraquat and glyphosate. It is widely used in agricultural production. The structural formula of glufosinate-ammonium is as follows : [0003] . [0004] The crude product of glufosinate-ammonium hydrochloride contains a large amount of inorganic salt by-products such as ammonium chloride and produces viscous organic impurities. There are also relevant reports on the research of glufosinate-ammonium hydrochloride purification process in China. For example, patent CN103819503 mentioned that glufosinate-ammonium hydrochloride was first Phosphine hydrochloride is ammoniated into a salt, and then combined with carbon dioxide to ...

AI Technical Summary

Problems solved by technology

[0004] The crude product of glufosinate-ammonium hydrochloride contains a large amount of inorganic salt by-products such as ammonium chloride and produces viscous organic impurities. There are also relevant reports on the purification process of glufosinate-ammonium hydrochloride in China. For example, patent CN103819503 mentions that glufosinate-ammonium Phosphine hydrochloride is ammonified into salt, and then mixed with carbon dioxide to obtain glufosinate-ammonium acid. This process introduces ammonium bicarbonate during the reaction process, which needs to be removed by thermal decomposition in the final product, which will easily lead to a decline in product quality, and a large amount of carbon dioxide is used , low utilization

In patent CN201110160129, glufosinate-ammonium hydrochloride is sequentially subjected to esterification reaction, hydrolysis reaction and neutralization reaction with ethylene oxide to obtain glufosinate-ammonium acid, and finally ammonia gas is passed to obtain glufosinate-ammonium ammonium salt. The process route is long and consumes Large, low yield, ethylene oxide is used in the neutralization reaction, the operation risk factor is large, and the cost is high