A kind of method of bisglyphosate mother liquor recycling

Abstract

The invention relates to a kind of using iminodiacetonitrile as the main raw material, through alkali hydrolysis or acid hydrolysis and alkali hydrolysis combined process, adding ammonium salt and heating deamination double decomposition reaction, recovering ammonia gas or / and regenerated diacid monosodium salt, through Diglyphosate mother liquor is directly hydrolyzed and hydrogen chloride is precipitated by the same ion effect to separate qualified sodium chloride by-products. The acid mother liquor can be recycled. The mother liquor, mother liquor that cannot be applied mechanically and washing water can be completely separated by adding calcium hydroxide. The aqueous alkali solution can regenerate raw materials and products, which can be used mechanically or separately to synthesize bisglyphosate, and the regenerated calcium hydroxide can be used repeatedly. The new process can realize the clean production of diglyphosate and the recycling and high value-added utilization of by-products.

Description

technical field [0001] The invention relates to a clean production process of a glyphosate intermediate diglyphosate, in particular to a method for recycling a diglyphosate mother liquor, and belongs to the technical field of pesticides and fine chemicals. Background technique [0002] Diglyphosate is an intermediate for the preparation of glyphosate, a broad-spectrum herbicide with the largest global consumption. The chemical name of glyphosate is N-phosphonomethylglycine. The control of deep-rooted malignant weeds is very effective. In recent years, the sales volume has gradually increased. It ranks first among the 50 largest pesticide varieties in the world. The market size exceeds 10 billion US dollars. It has been registered and widely used in more than 130 countries around the world. [0003] The industrial production of bisglyphosate is obtained by using iminodiacetic acid, phosphorous acid and formaldehyde under the catalysis of hydrochloric acid, heating to reflux c...

AI Technical Summary

Problems solved by technology

This method has too many times of solid-liquid separation, and the yield of diacid is only about 80%. A large amount of diacid waste water containing salt is concentrated and desalted, and the method of regeneration of evaporative condensate is used. The energy consumption is high, and the quality of salt is poor, so it is difficult to use.

[0007] At present, most enterprises adopt the method of desalting concentrated diglyphosate wastewater and regenerating evaporative condensate, but the existence of formaldehyde leads to biochemical difficulties, and there are problems such as high energy consumption, poor quality of waste salt, and difficulty in utilization.

There is no good method for the treatment of wastewater and mother liquor produced in the dinitrile process. Although there are membrane technologies for wastewater treatment and desalination processes, there are large initial investment, frequent clogging and damage of membranes, short service life, and high operating costs. The high problem has not yet been well resolved

This process saves the consumption of alkali and hydrochloric acid, but increases the consumption of ammonia and the refining of crude products. The process is longer and the investment is relatively large.

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