Method for recycling distillate water at top of alkali mother liquor rectifying tower in glyphosate production process

Abstract

The invention relates to a technology for producing glyphosate by a glycine method, and relates to a method for recycling distillate water at the top of an alkali mother liquor rectifying tower in a glyphosate production process. The method sequentially comprises the following steps: a) adding alkali to neutralize the acid mother liquor in the glyphosate process, and replacing triethylamine in a layering manner; b) rectifying the treated alkali mother liquor; condensing the fractions to recover methanol, triethylamine and water as recovery liquid; emptying ammonia to a tail gas absorption tower to obtain ammonia water; c) adding the recovery liquid into a hydrolysis kettle in the glyphosate production process by a glycine method to serve as industrial water; in the heating process of the hydrolysis procedure, methanol is distilled and recycled; and d) forming an acid mother liquor after the subsequent glyphosate production crystallization and solid-liquid separation processes of the remaining triethylamine hydrochloride along with the mother liquor are completed, and returning to the step a). The method has the advantages that the process steps are simplified, the equipment cost and the operation cost are reduced, and the adverse effect of fraction accumulation on glyphosate production is effectively avoided.

Description

Technical field [0001] The present invention relates to a technique for producing glyphosate in glycine method. Specifically, glycine method produces a glyphosate production process of glyphosate production in the process of recovery of mother liquors during glyphosate to produce a petridate rejection and utilization method. [0002] technical background [0003] The conventional process of glyphosate production of glycine method is: [0004] In the synthesis process, the synthesis liquid is prepared by glycine, phosphite dimethyl, polymethylene formaldehyde, methanol is a solvent, and triethylamine is a catalyst; the synthesis liquid is added to the synthesis of the acid to hydrolyze and moisture and remove the by-product; The product slurry after the crystallization process is added to the alkaline, and the product is stirred down; the product is solidiry separation and drying to obtain a herbidephine phosphine product, and the mother liquor after solid-liquid is glyphosate Sour...

AI Technical Summary

Problems solved by technology

During this process, the main components of the distillate water drawn from the top of the triethylamine distillation tower include water, methanol, triethylamine, and free ammonia. Among them, the methanol comes from the desolvation residue of the hydrolysis tank, and the free ammonia comes from the raw material glycine. In the early production and operation, The content of methanol and free ammonia is low, but as the production time continues, a large amount of methanol and free ammonia accumulate in the distillate water, which does not meet the discharge conditions, which seriously affects the energy efficiency of the entire glyphosate production system

The main problem is that the presence of methanol solvent reduces the yield of glyphosate; repeated rectification of distillate water causes a large amount of steam consumption in the repeated rectification process, which makes the steam consumption of the triethylamine rectification tower high; ammonia volatilization affects the rectification process. Distillation column pressure stability, etc.

Images