Esterification of unsaturated fatty acids by the fusel oil alcohols

Abstract

The aim of the research was to determine the regularities for esterification process of an unsaturated fatty acids by the fusel oil alcohols, including by individual 2-methylpropan-1-ol and 3-methylbutan-1-ol. As catalysts for esterification process the cation exchange resin KU-2-8 and the p-toluenesulfonic acid were used. It was established that during the esterification process of an unsaturated fatty acids by 3-methylbutan-1-ol in the presence of p-toluenesulfonic acid the acids conversion in 40 minutes of the reaction reaches 95.1 %, while in the presence of cation exchange resin it reaches 92.6 % for 300 minutes. Under these same conditions an unsaturated fatty acids conversion for esterification reaction with 2-methylpropan-1-ol in the presence of cation exchange resin KU-2-8 reaches only 78.9 % in 300 min. The use of benzene which forms a triple benzene-alcohol-water azeotropic mixture has a different effect on the achieved equilibrium conversion of acids when they interact with 2-methylpropane-1-ol and fusel oil. The maximum effect of the use of benzene is achieved in the esterification process of an unsaturated fatty acids by fusel oil in the presence of cation exchange resin KU-2-8: maximum conversion of unsaturated fatty acids is 83.2 %. In the absence of benzene it reaches only 22.6 %. Extreme dependence of an unsaturated fatty acids conversion on the reagents ratio was found. It is explained by the fact that in the presence of a high fusel oil excess the quotient of water-soluble alcohols increases. It worsens the drainage of water from the reactor and results in a low an unsaturated fatty acids conversion. The low value of the acids conversion by a small surplus of fusel oil is due to a decrease in the proportion of C2–C3 alcohols, which are also involved in the esterification process of an unsaturated fatty acids and are more reactive than higher alcohols. The accomplished studies show the expedience of using as a raw material for the production of esters of higher fatty acids of such substances as an unsaturated fatty acids (sunflover oil waste products) and fusel oil (waste of ethyl alcohol production) or of individual C4–C5 alcohols.