Improved pmida energy-saving synthesis method

Abstract

The invention relates to an improved pmida energy-saving synthesis method. The method comprises the steps of placing a sodium hydroxide solution into iminodiacetonitrile suspension, carrying out the hydrolysis to obtain a mixed solution of iminodiacetic acid disodium salt and ammonia, carrying out the deamination for the mixed solution to obtain a disodium iminodiacetate solution, placing acid into the disodium iminodiacetate solution, carrying out the acidification, then placing the phosphorous acid into the solution to reduce the solubility of the inorganic acid sodium salt, carrying out the thermal filtering to remove the sodium salt, and carrying out the condensation reaction for an obtained acidolysis solution and formaldehyde to obtain the pmida. The method is simple and easy, the use amount of water for alkaline hydrolysis can be reduced, the step for crystallizing the iminodiacetic acid is omitted, the loss of the iminodiacetic acid is reduced, the energy consumption is reduced, the pmida yield is increased, and the industrial production is facilitated.

Description

technical field [0001] The invention relates to an improved energy-saving synthesis method of diglyphosate, which belongs to the technical field of chemical industry. Background technique [0002] Glyphosate has the advantages of broad spectrum, high efficiency, and low toxicity. With the promotion of glyphosate-resistant transgenic crops, its usage is increasing, and it has become the world's largest herbicide in sales, with a very broad domestic and international market. Diglyphosate is an important intermediate for the synthesis of glyphosate. Diglyphosate can be obtained by condensation of iminodiacetic acid, phosphorous acid and formaldehyde under acidic conditions; A method for synthesizing phosphine, comprising: adding a suspension of iminodiacetic acid dropwise to a mixed solution of phosphorous acid, formaldehyde and hydrochloric acid, and incubating at a set temperature until the end of the reaction to obtain a suspension of diglyphosate; suspending diglyphosate A...

AI Technical Summary

Problems solved by technology

(1) Chloroacetic acid synthesis route has low yield, large amount of waste water, long process cycle, difficult operation, harsh conditions, high requirements for equipment materials and safety protection measures, and product yield is too sensitive to reaction conditions. High energy consumption, weak competitiveness, not suitable for mass industrial production

(2) Hydrocyanic acid process also has high production energy consumption and weak competitiveness. The by-products of the reaction not only bring a burden to the equipment, but also bring great inconvenience to the production process, reducing the yield of diglyphosate

(3) Diethanolamine method: The dehydrogenation reaction of this method is usually carried out at a higher temperature, and the reaction conditions are harsh. From an economic point of view, it is not suitable for industrial production

(4) Nitrilotriacetic acid method: This method is to use nitrilotriacetic acid as a raw material, and metal palladium catalyzes the reaction. my country's precious metal resources are in short supply, and it is used in industrial production, which increases production costs.

Although the process is simple, the reaction conditions are harsh and need to be carried out under high temperature and high pressure, the requirements for equipment materials are high, and the reaction produces a large number of by-products, the yield is very low, and it is not suitable for industrial production.