Method for preparating ethyl linoleate by catalysis of composite solid ultra-strong acid

Abstract

The present invention is a method of preparing the linoleic acid ethyl ester with the composite solid superacid catalyst. The production method the of linoleic acid ethyl ester in the existing industrialized production is the esterification reaction between the linoleic acid and the anhydrous ethanol ester with the concentrated sulfuric acid as the catalyst. The method has the problems of the large discharge of the acidic wastewater, the serious corrosion of the production equipment and so on. Therefore, the industrialized production urgently needs an environment-friendly solid acid catalyst. The method of preparing the linoleic acid ethyl ester with the composite solid superacid catalyst of the present invention is that the linoleic acid and the anhydrous ethanol with the molar ratio of 1 to between 1 and 10 are added into the reactor in order; the mixed solution is added with the SO42- / TiO2-SiO2, the composite solid superacid catalyst, whose weight is 1 to 10 percent of the weight of the linoleic acid; the mixed solution is stirred and heated with the protection of the nitrogen; the reaction is done for 2 to 10 hours at the return temperature of 40 DEG C; the solution is delaminated statically after the reaction; the products on the upper layer are decompressed and distilled under the pressure of minus 98.8 to minus 99.3 kPa; the distilled ingredients are collected at the temperature between 162 and 172 DEG C; then the refined inoleic acid ethyl ester can be got. The method of the present invention is suitable for the preparation of the linoleic acid ethyl ester in the industry.

Description

Technical field: [0001] The invention relates to a method for preparing ethyl linoleate, in particular to a method for preparing ethyl linoleate through esterification of linoleate catalyzed by a composite solid superacid. Background technique: [0002] Ethyl linoleate (9,12-octadecadienoic acid ethyl ester) is the main drug raw material for the prevention and treatment of heart and brain thrombosis, arteriosclerosis and other diseases. In the cosmetics industry, this product is used as a nutritional aid to accelerate the renewal of skin cells , whitening skin, and also has moisturizing, anti-allergic, conditioning and other functions, and has been widely used in the pharmaceutical industry, cosmetics industry, and health food industry. [0003] However, the present industrialized method for producing ethyl linoleate is prepared by the esterification reaction of linoleic acid and absolute ethanol under the catalysis of concentrated sulfuric acid. This method has problems suc...

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Problems solved by technology

[0003] However, the present industrialized method for producing ethyl linoleate is prepared by the esterification reaction of linoleic acid and absolute ethanol under the catalysis of concentrated sulfuric acid. This method has problems such as a large amount of acid waste water discharge and serious corrosion of production equipment. Moreover, due to the strong oxidizing properties of concentrated sulfuric acid, the unsaturated bonds in the linoleic acid molecule will be destroyed during the esterification reaction, resulting in a decrease in the iodine value of the product, a decrease in product quality, and SO 4 2- / TiO 2 Solid superacid catalysts are used as catalysts for the esterification of linoleic acid, and good results have been achieved. However, solid superacids have high cost and short service life, making it difficult to realize industrialization, and their application is limited.