Glyphosate continuous desolventizing production process

Abstract

The invention relates to a glyphosate continuous desolventizing production process comprising the following steps of: hydrolyzing glyphosate materiel; continuously adding obtained acidizing fluid to three desolventizing kettles connected in series; controlling the temperature of the first-stage desolventizing kettle at 70-90 DEG C to remove methylal in the material; controlling the temperature of the second-stage desolventizing kettle at 90-105 DEG C to remove methanol in the material; controlling the temperature of the third-stage desolventizing kettle at 105-118 DEG C to remove hydrogen chloride in the material; then collecting the desolventized material in a crystallization kettle to continue desolventizing until final temperature; and then obtaining glyphosate raw powder respectively by thermal-insulation crystallization, centrifugal separation and drying. Compared with the prior art, the production process adopts a continuous desolventizing mode, and therefore, the glyphosate yield is high; and collecting solvents step by step is adopted, thereby avoiding repeat operation and reducing equipment investment and energy consumption.

Description

technical field [0001] The invention relates to a production process, in particular to a continuous glyphosate precipitation production process. Background technique [0002] Glyphosate is currently used as a herbicide with superior performance. There are many preparation methods, and the alkyl ester method is one of the preparation methods. After heating and dissolving paraformaldehyde (or formaldehyde) in a methanol solution containing triethylamine, glycine and dimethyl phosphite (or trimethyl phosphite) are added for condensation reaction respectively, and then mixed to the reaction Add hydrochloric acid to the solution to acidify, then heat up to remove solvents such as methanol and methylal, and then obtain glyphosate acid crystals. The reaction process is as follows: [0003] [0004] [0005] [0006] At present, in industrial production, the triethylamine salt (II) of the precursor compound dimethyl glyphosate is hydrolyzed with hydrochloric acid in a reac...

AI Technical Summary

Problems solved by technology

At present, the desolvation methods used in industrial production are to inject the acidification solution into the reactor, and use the intermittent heating method to remove the solvent. Although the injected hydrolyzate is fed according to the specified load of the reactor, due to the reaction system The materials and solvents are volatile components. As the temperature rises and the hydrolysis reaction proceeds, the amount of materials in the kettle will gradually decrease, and the upper empty space in the reaction kettle will continue to increase, resulting in the ineffectiveness of the heating jacket for these empty spaces. The heating ratio also increases, causing the reaction kettle to be heated up and cooled down.

According to the current feeding method, this problem is common but cannot be solved

This is not only another factor that increases energy waste, but also reduces the utilization rate of the reactor, which affects production efficiency and output. On the other hand, the mixed solvent needs to be recovered through the rectification tower, so there is a situation of repeated recovery of methanol , resulting in a waste of energy

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