Application of organic phosphonic acid as esterification reaction catalyst

Abstract

The invention discloses application of organic phosphonic acid as a catalyst of an esterification reaction, which is to use synthesized organic phosphonic acid as the catalyst of esterification reaction of carboxylic acid and alcohol. The catalyst has the advantages that: (1) compared with the prior inorganic acid catalyst, the organic phosphonic acid has larger modification space in structure, so that the catalyst and raw materials (the carboxylic acid and the alcohol) have better intersolubility, and catalysis effect of the catalyst is improved; (2) the organic phosphonic acid is solid and can realize separation of the catalyst and a product in a distillation mode with simple post-treatment; (3) a carbon-phosphorus bond in the organic phosphonic acid is stable, and cannot be easily hydrolyzed in the esterifying process, thereby contributing to recycle of the catalyst; (4) the organic phosphonic acid as the catalyst of the esterification reaction has less corrosion to metal equipment; and (5) the organic phosphonic acid as the catalyst cannot generate side reactions, such as oxidation, dehydration in an alcohol molecule or among molecules and the like; and the reaction can be controlled easily, and yield of the product is high.

Description

technical field [0001] The invention relates to a catalyst used in the esterification reaction of carboxylic acid and alcohol, in particular to the application of an organic phosphonic acid as a catalyst for the esterification reaction. Background technique [0002] For a long time, the esterification reaction of carboxylic acid and alcohol has mainly used concentrated sulfuric acid as a catalyst, and there are some disadvantages in the use of concentrated sulfuric acid for catalysis: (1) under the esterification conditions, while the concentrated sulfuric acid catalyzes the esterification reaction, there are also oxidation and Dehydration has led to a series of side reactions, reducing the yield of the esterification reaction; (2) due to the strong corrosiveness of concentrated sulfuric acid, the enamel reaction kettle and high-grade stainless steel pipes need to be regularly updated; (3) after Disposal is troublesome, and a large amount of acidic waste liquid is produced, ...

AI Technical Summary

Problems solved by technology

[0002] For a long time, the esterification reaction of carboxylic acid and alcohol has mainly used concentrated sulfuric acid as a catalyst, and there are some disadvantages in the use of concentrated sulfuric acid for catalysis: (1) under the esterification conditions, while the concentrated sulfuric acid catalyzes the esterification reaction, there are also oxidation and Dehydration has led to a series of side reactions, reducing the yield of the esterification reaction; (2) due to the strong corrosiveness of concentrated sulfuric acid, the enamel reaction kettle and high-grade stainless steel pipes need to be regularly updated; (3) after Disposal is troublesome and produces a large amount of acidic waste liquid, which pollutes the environment

Although solid catalysts such as solid superacids and Lewis acids can be recycled, the catalysts must be treated after recovery to maintain high catalytic activity, which greatly increases the cost of catalysts.

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