Process for producing glycolic acid from monochloroacetic acid

Abstract

The invention discloses a process for producing glycollic acid by using monochloro acetic acid. The process comprises a rough maching process of carrying out hydrolysis, concentration, cooling and throwing on monochloro acetic acid and sodium carbonate so as to obtain a crude solid glycollic acid product, The process is characterized in that a fine machining process is further carried out on the basis of the rough machining process, wherein the fine machining process comprises the following steps of: a, mixing the crude solid glycollic acid product with methanol according to a weight ratio of 1:(3-5); b, sufficiently dissolving the mixture at 50-55 DEG C, and holding for 0.3-1 hour; and c, cooling to 1-3 DEG C, throwing the material so as to obtain two substances, namely a solid substance and a liquid substance, wherein the liquid substance is a crude methyl glycolate product and the solid substance is a fine glycollic acid product. The process has the beneficial effects that the chlorine content of the fine glycollic acid product prepared by using the process is 10PPM, so that the limit of raw materials is overcome, the problem of chlorine content is well solved, and meanwhile methyl glycolate with good quality can be produced, so that recycling of energy is facilitated, and remarkable economic and social effects are achieved.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and relates to a production process of glycolic acid, in particular to a production process of glycolic acid whose chlorine content can reach 10PPM. Background technique [0002] Glycolic acid, also known as glycolic acid, is the simplest hydroxy acid, which is low in nature and difficult to separate and purify. Industrial production uses synthetic methods. Glycolic acid is a colorless, odorless, translucent solid with a melting point of 80 degrees Celsius, decomposes at the boiling point, and is soluble in water, methanol, ethanol, acetic acid, and acid, but almost insoluble in hydrocarbon solvents. Used in water treatment, detergent, cosmetic industry: mainly used in emulsifier, penetrating agent, softener, lubricant, hair conditioner. With the development of science and technology, the requirements for the content of chloride ions in its aqueous solution are getting higher and hig...

AI Technical Summary

Problems solved by technology

In the glycolic acid obtained by this production process, the chloride ion exceeds the standard seriously, which affects the user's use and restricts the production of the product. The chloride ion content reaches 200PPM

[0005] 2) Use hydroxyacetonitrile as a raw material for acidolysis, then esterification and purification, then hydrolyze the ester to obtain crude glycolic acid, and refine it to obtain glycolic acid liquid with a chlorine content of 10PPM. certain danger

[0006] Other methods are also subject to limitations due to yield and operational reasons