Bipolar membrane electrodialysis cyclization method for ortho-dihalogenated carboxylic acid

Abstract

The invention relates to a bipolar membrane electrodialysis cyclization method for ortho-dihalogenated carboxylic acid, belonging to the field of industrial sewage treatment. The bipolar membrane electrodialysis cyclization method for ortho-dihalogenated carboxylic acid comprises the following steps: continuously increasing a pH value in virtue of dissociated hydroxide ions in an alkali liquor chamber of a first bipolar membrane device (a two-chamber bipolar membrane device) so as to allow an ortho-dihalogenated carboxylic acid solution to undergo a cyclization reaction in the alkali liquor chamber with a pH value of 10-13 and to remove halogen, thereby obtaining cyclized carboxylate; and allowing the cyclized carboxylate to pass through a cation exchange membrane in a second bipolar membrane device (a two-chamber bipolar membrane device) so as to obtain sodium hydroxide and to obtain cyclized carboxylic acid when a pH value in an acid chamber decreases to 0.5 or less. Therefore, thebipolar membrane electrodialysis cyclization method for ortho-dihalogenated carboxylic acid in the invention effectively eliminates the addition of acid and alkali, reduces cost and pollution, and cansignificantly improve economic benefits.

Description

technical field [0001] The invention belongs to the field of industrial sewage treatment, and relates to a bipolar membrane electrodialysis cyclization method of ortho-dihalogenated carboxylic acid. Background technique [0002] Bipolar membrane electrodialysis, as an electric-driven composite membrane separation technology, has outstanding performance in the fields of acid-base preparation and recovery, food processing and processing, and separation of chemical materials. Due to the characteristics of bipolar membranes, a variety of different processes can be designed by cleverly combining with ion exchange membranes. [0003] At present, the investment cost of the micro-waste treatment process in the pharmaceutical industry is too high, the process is cumbersome, and the phenomenon of secondary pollution is relatively serious. The main method is still to use the traditional addition of sodium hydroxide and hydrogen chloride as strong alkali and strong acid for waste treat...

AI Technical Summary

Problems solved by technology

The treatment process requires a large amount of acid-base solution, which greatly increases the difficulty of process cost control and the degree of pollution

[0004] In addition, in terms of cyclization of ortho-dihalocarboxylic acids, the existing bipolar membrane electrodialysis technology does not have relevant experimental results and research content to show that bipolar membrane electrodialysis can successfully cyclize such compounds and produce

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