Method of using methionine mother liquid containing potassium carbonate or potassium hydrogen carbonate to prepare zinc methionine zinc chelate

Abstract

The invention discloses a method of using methionine mother liquid containing potassium carbonate or potassium hydrogen carbonate to prepare methionine zinc chelate. The method includes following steps: concentrating methionine crystallization mother liquid to increase content of total methionine (containing methionine dipeptide) of a system to 8-15wt%, and promoting potassium hydrogen carbonate to be converted into potassium carbonate; transferring concentrated mother liquid for bipolar film electrodialysis for further acidifying and recycling potassium ions, desalting until a molar ratio ofmethionine to potassium ions in acid chamber mother liquid is 1:0.8-1.1, adding zinc salt of 0.5 molar total methionine equivalent weight, allowing reaction at 70-90 DEG C for 70-90min, cooling, crystallizing, separating, and drying to the methionine zinc chelate. The method is simple, practical and high in methionine and potassium ion recycling rate; physical property that the methionine zinc chelate is insoluble in water is utilized to realize separation of methionine from water-soluble impurities in the mother liquid, and the methionine zinc chelate which is a feed-grade trace element nutritional agent having high economic value.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a method for preparing zinc methionine chelate from methionine mother liquor containing potassium carbonate or potassium bicarbonate. Background technique [0002] D, L-methionine, also known as methionine, is an important biological nutrient and pharmaceutical and chemical raw material. As an essential amino acid for the human body and the first limiting amino acid for animals, it cannot be synthesized by the organism itself and must be ingested from food. [0003] The industrial production of D,L-methionine is still dominated by chemical synthesis. The chemical synthesis method uses cyanide, methyl mercaptan, acrolein, carbon dioxide, ammonia and other raw materials to synthesize 5-(2-methylthioethyl)hydantoin (referred to as hydantoin) through a series of reactions. Under the action of alkaline substances such as potassium hydroxide and potassium carbonate, it is h...

AI Technical Summary

Problems solved by technology

[0010] (1) Direct extraction of part of the methionine crystallization mother liquor causes waste of resources and pressure on environmental protection;

[0011] (2) The recovery of methionine and potassium salts is limited by secondary crystallization of the extracted mother liquor directly or by introducing lower alcohols;

[0012] (3) Through the combination of microporous membrane, cationic resin, electrodialysis and other technologies, the components in the mother liquor are gradually separated to realize separate recovery and treatment. The process is complicated and the cost is high. The recovered potassium sulfate cannot be reused in the system and produces a large amount of waste water