Method for synthesizing methyl laurate by recycling cerium phosphotungstate catalyst

Abstract

The invention relates to a method for synthesizing methyl laurate by recycling a cerium phosphotungstate catalyst, which belongs to the technical field of chemical industry. The method comprises the following steps of: adding lauric acid and absolute methanol to a reaction kettle in proportion; adding cerium phosphotungstate accounting for 7%-7.5% of the weight of the lauric acid as the catalyst; decompressing and evaporating unreacted methanol after heating reflux reaction; carrying out centrifugal separation on the methyl laurate and the solid cerium phosphotungstate catalyst which are positioned in the reaction kettle to obtain the methyl laurate on an upper layer and the solid cerium phosphotungstate catalyst on a lower layer; dissolving the lower solid cerium phosphotungstate catalyst by using deionized water, and adding hydrochloric acid to blend the pH value of a solution (1, filtering to remove water-insoluble carbon deposits and obtain a cerium phosphotungstate water solution, and concentrating and crystallizing the cerium phosphotungstate water solution to obtain the solid cerium phosphotungstate used as the catalyst for next reaction). The method disclosed by the invention recycles the cerium phosphotungstate as the catalyst of the reaction of the lauric acid and the absolute methanol and achieves the transformation rate of the lauric acid more than 97% every time.

Description

technical field [0001] The invention relates to a method for synthesizing methyl laurate by recycling a cerium phosphotungstate catalyst, which belongs to the technical field of chemical industry. Background technique [0002] Methyl laurate is an oily liquid with aroma similar to wine and flowers, and is mainly used as gas chromatography stationary liquid, food additive and organic synthesis reagent. In the industrial production of methyl laurate, sulfuric acid, cationic resin, etc. are used to catalyze the reaction of lauric acid and methanol. Using concentrated sulfuric acid as a catalyst has many side reactions, discharges acidic waste water, pollutes the environment, and severely corrodes equipment; using cationic resin as a catalyst for esterification, the surface of the catalyst is covered with a layer of carbon deposits after the reaction, the catalyst is deactivated, and cannot be reused. Application, surface area carbon treatment technology is still in the researc...

AI Technical Summary

Problems solved by technology

Using concentrated sulfuric acid as a catalyst has many side reactions, discharges acidic waste water, pollutes the environment, and severely corrodes equipment; using cationic resin as a catalyst for esterification, the surface of the catalyst is covered with a layer of carbon deposits after the reaction, the catalyst is deactivated, and cannot be reused. Application, surface area carbon treatment technology is still in the research and development stage, and can only be treated as industrial waste

Studies have reported that whether solid superacids or heteropolyacids are used directly or after loading, there will be carbon deposition on the surface of the catalyst, which will reduce the catalytic activity, and the catalyst will fall off on the loaded catalyst, reducing the catalytic performance. reaction occurs