Modified ion exchange resin catalyst and its application

Abstract

The present invention relates to modified ion exchange resin catalyst, and is especially one kind of tin dichloride modified cation exchange resin catalyst and its application as ammonium lactate esterifying catalyst. The tin dichloride modified cation exchange resin catalyst is prepared through the following steps: 1. drying hydrogen type strong acid cation exchange resin to constant weight; 2. reaction of the dried hydrogen type strong acid cation exchange resin and tin dichloride inside alcohol solution; and 3. washing the modified resin with anhydrous ethanol for several times, drying in a vacuum drier to eliminate ethanol and obtain the modified cation exchange resin catalyst. The catalyst has high esterification yield and no corrosion to the production apparatus.

Description

technical field [0001] The invention relates to a cationic exchange resin catalyst modified by tin dichloride and the application of the catalyst as an ammonium lactate esterification catalyst. Background technique [0002] Lactate is a class of lactic acid derivatives with excellent biodegradability, and has been widely used in food, medicine, coatings, electronics and other departments. Lactic acid is used as raw material in the traditional lactic acid ester synthesis process, which is generally produced by fermentation, and the process of extracting lactic acid from the fermentation broth must be carried out before esterification, but this process has cumbersome processes, many by-products, and raw materials Corrosion and other deficiencies in the reaction device limit the reduction of the cost of lactic acid esterification to a certain extent. [0003] In the lactic acid fermentation process, ammonia water is used as a neutralizing agent to obtain the fermentation produ...

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Problems solved by technology

[0004] Chinese patents CN1369490A and CN1104254 disclose the use of concentrated sulfuric acid as a catalyst to catalyze the esterification of ammonium lactate and alcohol. Although the ideal esterification rate can be obtained with concentrated sulfuric acid as a catalyst, the esterification is accompanied by side reactions such as oxidation and vulcanization, and After the reaction, in order to remove excess sulfuric acid, neutralization and water treatment are required, which makes the production process complicated

Journal of Hebei University of Technology VOL.31.N 06, 7-10, 2002. reported the use of AlCl 3 (Lewis acid) is used as a catalyst to esterify ammonium lactate to generate ethyl lactate, which solves the shortcomings of severe equipment corrosion, many by-products and complicated post-treatment processes, but the esterification efficiency is very low, only 22.45%.