Device and process for washing glycine crude product through alcohol phase method

Abstract

The invention relates to a device and a process for washing a glycine crude product through an alcohol phase method. A glycine centrifuge is connected with a diluted methanol washing tank which is connected with a glycine extraction kettle through a diluted methanol pump, the glycine extraction kettle is connected with an extracted glycine centrifuge which is connected with a methanol rectifying tower through an extract transfer pump, and the methanol rectifying system is connected to a red ammonium concentration system. Alcohol and chloroacetic acid are taken as a solvent and an initial raw material respectively in the process, a glycine product meeting glyphosate synthesis requirements and reaching national standards (main content being greater than or equal to 98.5% and chlorine root being less than or equal to 0.4%) is obtained by treating the glycine crude product (glycine main content being 93-96%, chlorine root being 2-4% and other impurities being lower than 1%) produced by newprocesses like a mixed solvent or organic amine or novel halogen formula reagent method through a systematic industrial washing process, and glycine synthesis yield is unaffected; wastewater is completely recycled into a system, so that clean production is realized.

Description

technical field [0001] The invention discloses a device and process for producing glycine by an alcohol phase method, which belongs to the technical field of chemical production, and in particular relates to a new method for washing materials produced by an alcohol phase method for glycine and waste water reuse. Background technique [0002] Glycine is aminoacetic acid, as an important fine chemical intermediate and chemical raw material, it is widely used in the fields of pesticide glyphosate, medicine, food and feed additives, etc. At present, the domestic industrialized production process of glycine still adopts the traditional ammonolysis method of chloroacetic acid using water as a solvent. This method has the following problems: (1) High production cost. The hexamethamine catalyst cannot be recycled; 1 ton of glycine needs to consume about 6-7 tons of steam; the recovery of low-value-added ammonium chloride requires high equipment and pipelines, high maintenance freque...

AI Technical Summary

Problems solved by technology

At present, the domestic industrial production process of glycine still adopts the traditional ammonolysis method of chloroacetic acid with water as the solvent. This method has the following problems: (1) High production cost

The urotropine catalyst cannot be recovered; 1 ton of glycine needs to consume about 6-7 tons of steam; the recovery of low-value-added ammonium chloride requires high equipment and pipelines, high maintenance frequency, and high equipment operation and maintenance costs

(2) Low yield, difficult to break through 85%

The system in the aqueous phase is highly alkaline, and the conversion rate of chloroacetic acid into glycine is low, and about 15% of chloroacetic acid is hydrolyzed to produce glycolic acid; when high temperature ammonia is insufficient, it is easy to produce iminodiacetic acid [NH(CH 2 COOH) 2 ] and aminotriacetic acid [N(CH 2 COOH) 3 ] and other by-products

(3) Environmental risks cannot be completely eliminated

However, it is difficult to control the amount of ammonia, the end point of the reaction, and the complete recovery of triethylamine, and it is easy to cause the content of ammonium chloride in glycine to be too high, which cannot meet the requirements of the national standard (the main content is ≥ 98.5%, and the content of chloride radicals is less than or equal to 0.4%). Glycine products suitable for glyphosate production

Images