Method for Synthesizing Glyoxylic Acid by Ozonation of Maleic Anhydride Mixed Solvent

Abstract

The invention relates to a method for synthesizing glyoxylic acid by means of ozonizing maleic anhydride and mixed solvents, and belongs to the field of technologies for preparing glyoxylic acid. The method for synthesizing the glyoxylic acid by means of ozonizing the maleic anhydride and the mixed solvents is low in cost. The method includes steps of carrying out hydrolysis, ozone oxidation, reduction, reduced-pressure distillation, crystallization and the like on the inexpensive maleic anhydride in the mixed solvents to ultimately obtain glyoxylic acid solid. The method has the advantages that the glyoxylic acid solid with high purity can be directly obtained by the aid of the method, and products are high in quality and wide in application; the method is easy to implement and high in glyoxylic acid yield, the maleic anhydride can be converted into the glyoxylic acid at a low price, the method can be used for industrial large-scale production, and certain contribution can be made for solving the problem of situation of excessive maleic anhydride; optimization of the traditional processes for producing the glyoxylic acid and elimination of backward processes can be stimulated, environment-friendly oxidizing agents are adopted, and accordingly huge contribution can be made for environmental protection.

Description

technical field [0001] The invention relates to a method for synthesizing glyoxylic acid by ozonation of a mixed solvent of maleic anhydride, and belongs to the technical field of glyoxylic acid preparation. Background technique [0002] Glyoxylic acid is an important organic chemical intermediate raw material. In recent years, its downstream products have been continuously developed, and glyoxylic acid has a good market prospect. Glyoxylic acid can synthesize vanillin, 2-hydroxyquinoline, 2-hydroxyphosphoacetic acid, D-hydroxyphenylglycine, allantoin, etc. In recent years, with the rapid development and development of glyoxylic acid downstream products, the market Demand continues to expand. In particular, the demand for high-purity solid glyoxylic acid will increase, and the application range will be wider. [0003] At present, the production methods of glyoxylic acid mainly include oxalic acid electrolytic reduction method, glyoxal oxidation method, glycolic acid select...

AI Technical Summary

Problems solved by technology

The oxalic acid electrolytic reduction method and the glyoxal oxidation method have both realized industrial production, however, the oxalic acid electrolytic reduction method mainly has the disadvantages that the yield of the equipment is low when the space is empty, and the product contains a large amount of oxalic acid that is difficult to separate.

The glyoxal oxidation method is the most widely used, but its disadvantages are large solvent loss, easy corrosion of equipment, low yield of raw materials, poor product quality, and serious environmental pollution

The disadvantage of selective oxidation of glycolic acid is that the cost of synthesis is relatively high, and the key is to obtain a highly selective catalyst

Dibromoacetic acid hydrolysis reaction conditions are mild, but the separation of reaction products is difficult, and the price of raw materials used is high, and the product yield and quality are not very satisfactory.

Adopting this method requires higher requirements for ozone generators, higher equipment investment, greater energy consumption, and the production rate is highly dependent on hydrogenation catalysts, requiring expensive hydrogenation catalysts, resulting in higher production costs.