A device and process for washing crude glycine by alcohol phase method

Abstract

The patent of the invention relates to the device and process for washing crude glycine by alcohol phase method. The glycine centrifuge is connected with the dilute methanol washing tank, and the dilute methanol washing tank is connected with the glycine extraction kettle through the dilute methanol pump; the glycine extraction kettle is connected with the extraction glycine centrifuge. ; The extraction glycine centrifuge is connected to the methanol rectification tower through the extract liquid transfer pump, and the methanol rectification tower is connected to the red ammonium concentration system. In the process, alcohol is used as a solvent, chloroacetic acid is used as an initial raw material, and crude glycine is produced by using mixed solvents or organic amines or new halogen-type formula reagents (the main content of glycine is 93% to 96%, and the content of chloride radicals is 2% to 4%, other impurities less than 1%), after the systematic industrial washing process, a glycine product that meets the glyphosate synthesis and national standards (main content ≥ 98.5%, chloride ≤ 0.4%) can be obtained without affecting The yield of glycine synthesis is high, and the waste water is completely reused in the system to achieve clean production.

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

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