A clean production process for amino acids such as iminodiacetic acid

Abstract

The invention relates to a clean production method for amino acids such as iminodiacetic acid. The method comprises the steps: carrying out alkaline hydrolysis on amino-nitrile by adopting cheap lime cream, and carrying out deamination, so as to obtain an iminodiacetic acid calcium salt crude product; suspending the obtained iminodiacetic acid calcium salt crude product into water or mother liquor, adding sulfuric acid or other inorganic acid into the water or mother liquor for acidification, and filtering out an inorganic calcium salt filter cake with low water solubility; and subjecting the filter liquor to cooling and crystallization, carrying out separation so as to obtain iminodiacetic acid solids, and applying the crystallization mother liquor to an acidification reaction of next batch mechanically. During the acidification by the sulfuric acid, gypsum can be converted into calcium carbonate and ammonium sulfate by further using a byproduct, i.e., ammonia water of an alkaline hydrolysis process and carbon dioxide in flue gas, so as to directly generate compound fertilizers; the calcium carbonate can also be separated, and ammonium sulfate crystals can also be concentrated; and the calcium carbonate can be sold as a byproduct or be subjected to heated decomposition so as to obtain a quicklime raw material which can be applied mechanically. According to the novel process, the complete utilization of resources can be realized, the reaction selectivity is higher, the production of colored byproducts is reduced, and a concentrating process for removing waste salts such as sodium sulfate and sodium chloride and a wastewater treatment link are avoided; and due to concentration, the use level of a decolorant can be greatly lowered, the energy saving and consumption lowering effects are remarkable, and the production cost is reduced remarkably.

Description

technical field [0001] The invention relates to a clean production process for amino acids such as iminodiacetic acid, and belongs to the technical fields of pesticides, fertilizers and fine chemicals. Background technique [0002] Iminodiacetic acid, CAS No. 142-73-4, alias iminodiacetic acid, N-(carboxymethyl) glycine, aminodiacetic acid, referred to as IDA. Iminodiacetic acid is mainly used as an intermediate in the synthesis of glyphosate and other pesticides, and can also be used as a phosphorus-releasing organic double-effect fertilizer, a raw material for ion exchange resins, rubber, electroplating, and food additives. [0003] Iminodiacetic acid has the following synthetic routes: [0004] 1. Chloroacetic acid method Chloroacetic acid reacts with ammonia water or sodium hydroxide to produce sodium chloroacetate, then reacts with hydrazine hydrate to form hydrazinodiacetic acid, and then acidifies with hydrochloric acid under the action of sodium nitrite to form imin...

AI Technical Summary

Problems solved by technology

This method has the problems of loss of alkali hydrolysis yield and easy production of colored substances. The yield of diacid is only about 90%. A large amount of diacid wastewater containing salt is concentrated and desalinated, and the method of regeneration of evaporative condensate is used. The energy consumption is high, and the salt Poor quality, difficult to use

Although the method for the synthesis of iminodiacetic acid by the acid hydrolysis of iminodiacetonitrile that we developed has reduced the use of by-products and sodium hydroxide, avoided production waste water, and obtained valuable ammonium chloride, there are complicated refining processes and solid The disadvantages of many times of liquid separation and large investment

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