A kind of catalyst for preparing chloroacetic acid by catalyzing acetic acid and its preparation and application

Abstract

The invention relates to a catalyst for preparing chloroacetic acid from acetic acid and its preparation and application. The preparation method of the catalyst is as follows: (1) Mix phenol and formaldehyde aqueous solution, add metal powder and metal oxide, disperse and then heat the reaction (2) continue to add paraformaldehyde solid and / or hexamethylenetetramine in the reaction gained solution, stir and mix evenly, obtain the viscous liquid mixture, discharge while hot, granulate, obtain bar-shaped particle: ( 3) Dry the obtained strip-shaped particles, heat up and solidify, and then continue to heat up under the protection of an inert gas to obtain carbonized / graphitized particles; (4) finally elute the obtained carbonized / graphitized particles with aqueous nitric acid solution to obtain the target product. Compared with the prior art, the present invention effectively solves the problems of separation of the catalyst and the reaction solution, greatly improves the selectivity of the main product chloroacetic acid, and greatly reduces the production cost and labor intensity.

Description

technical field [0001] The invention belongs to the technical field of catalyst preparation, and relates to a catalyst for catalyzing acetic acid to prepare chloroacetic acid, as well as its preparation and application. Background technique [0002] Chloroacetic acid (that is, monochloroacetic acid) is an important fine chemical intermediate, known as industrial vitamins, and there are hundreds of downstream products using chloroacetic acid as raw materials. It is widely used in food, materials, electronic appliances and other fields, and occupies an important position in the chemical industry. [0003] The output of chloroacetic acid is increasing year by year. The output of chloroacetic acid in my country accounts for 50% of the world's total output. It is the main producer of chloroacetic acid products. Over the years, the production capacity has increased rapidly, but the production technology has developed very slowly. Most manufacturers The technology of the former Sov...

AI Technical Summary

Problems solved by technology

[0004] The sulfur catalytic chlorination method mainly has the following problems: (1) the sulfur catalyst is powdery in the reaction system, and it is difficult to separate it from the product and unreacted raw materials after the reaction. The product chloroacetic acid contains a small amount of sulfur. In the case of increasingly high quality requirements, even chloroacetic acid containing a very small amount of sulfur cannot meet the requirements of pharmaceutical fields, food fields, electrical appliances, etc.

(2) The composition of the mother liquor obtained after separating chloroacetic acid is complex, and direct reuse leads to a reduction in reaction performance and a further decline in product quality

(3) A small amount of chloroacetic acid will be deeply chlorinated to generate dichloroacetic acid in the reaction process, and the separation of dichloroacetic acid and chloroacetic acid is extremely difficult. Usually, the method of selective catalytic dechlorination is used to convert dichloroacetic acid into chloroacetic acid, but the product A small amount of sulfur can seriously poison the catalytic dechlorination catalyst, and the catalyst will be deactivated quickly, which will increase the cost of the catalyst in production

(4) It is difficult to dispose of the generated solid waste containing sulfur, and it is also difficult to dispose of the generated liquid waste

(5) Intermittent operation is adopted, the batch quality is unstable, the production capacity of a single set is small, the production labor intensity is high, and the cost is high

Even with continuous operation, there is still the problem of separation of catalyst acetic anhydride