Treatment method of mother liquor produced by preparing chloroacetic acid through hydrogenation method

Abstract

The invention belongs to the technical field of chloroacetic acid production, and particularly relates to a treatment method of mother liquor produced by preparing chloroacetic acid through a hydrogenation method, and the method comprises the following steps: (1) neutralization: neutralizing the mother liquor with an alkaline substance until the pH value is equal to 7-7.5; (2) condensation: dropwise adding ethylenediamine and sodium hydroxide; (3) hydrolysis: continuously dropwise adding sodium hydroxide until the pH value is greater than 13, heating to 75-80 DEG C, keeping the temperature for2-2.5 hours, adding activated carbon for decolorization, and filtering; (4) acidification: neutralizing the filtrate with sulfuric acid or hydrochloric acid, separating out EDTA, filtering, and drying EDTA to obtain an EDTA product; (5) desalting: dehydrating the acidified and filtered filtrate, centrifugally desalting to obtain a hydroxyethyl acid crude product, and refining to obtain a hydroxyethyl acid product. According to the treatment method provided by the invention, the mother liquor is treated, the treatment cost is low, the pollution is little, two fine chemicals can be obtained, waste is turned into wealth, resources are recycled, and a big problem in the industry is solved.

Description

technical field [0001] The invention belongs to the technical field of chloroacetic acid production, and in particular relates to a treatment method for the mother liquor produced by the hydrogenation method to prepare chloroacetic acid. Background technique [0002] Chloroacetic acid is a colorless or white crystalline organic carboxylic acid, an important fine chemical intermediate, mainly used in the production of pesticides, medicines, food additives, feed additives, adhesives, water treatment agents and other fine organic chemical products , has a wide range of uses. The production methods of chloroacetic acid include trichlorethylene hydrolysis method, chloroacetyl chloride method and acetic acid catalytic chlorination method. Can be applied to industrial production is mainly acetic acid catalytic chlorination. [0003] At home and abroad, the acetic acid catalytic chlorination method is generally used for the production of chloroacetic acid. The catalyst used in thi...

AI Technical Summary

Problems solved by technology

The mother liquor treatment method that crystallization method is prepared chloroacetic acid produces has multiple: CN1129210A discloses a kind of method of producing dichloroacetic acid, wherein adopts chloroacetic acid mother liquor to produce dichloroacetic acid; CN106008200A discloses a kind of recovery process of chloroacetic acid mother liquor, is The technology that adopts chloroacetic acid mother liquor to produce sodium oxalate and glycolic acid; CN211502815U discloses a kind of chloroacetic acid mother liquor combustion device; "Research" article; "Tianjin Chemical Industry" published the article "Preparation of Trichloroacetic Acid from Chloroacetic Acid Mother Liquor" by Guan Wenguang and Tian Jinli in the first issue of 1997; "Research on the Production of Methyl Dichloroacetate and Thioglycolic Acid"; "Journal of Taiyuan University of Technology" published the article "Research on the Preparation of 2-Hydroxyquinoxaline Using Chloroacetic Acid Mother Liquor" by Lu Zhiping in November 2003; "Chemical Industry In February 2013, "Journal of Chinese Academy of Sciences" published the article "Separation of Monochloroacetic Acid and Dichloroacetic Acid by Trioctylamine Complex Extraction" by Chen Yingying. It is a treatment method for the mother liquor produced by the crystallization method to prepare chloroacetic acid. Since the composition of the mother liquor produced by the hydrogenation method is different from that produced by the crystallization method, the above treatment methods cannot be used to deal with the hydrogenation method. The mother liquor that chloroacetic acid produces; And for CN211502815U " a kind of chloroacetic acid mother liquor combustion device " disclosed a kind of method and device of incinerating chloroacetic acid mother liquor, also may be able to handle hydrogenation method and prepare the mother liquor that chloroacetic acid produces, but this method will The materials are all destroyed, the cost is high, and the materials contain chlorine elements. The incineration process will produce hydrogen chloride gas, which will seriously corrode the equipment and the post-processing is also troublesome.