Enzymatic Epoxidation of Soybean Oil Using Ionic Liquid as Reaction Media

Abstract

An ionic liquid (IL) system for the enzymatic epoxidation of soybean oil was studied. The effects of active oxygen carriers (different fatty acids) and ILs ([Bmim]PF₆ and [Bmim]BF₄) on the enzymatic epoxidation were investigated. Response surface methodology (RSM) was used to study and optimize the effects of variables (reaction time, reaction temperature, molar ratio of H₂O₂/C=C-bonds, and molar ratio of fatty acid/C=C-bonds) on the epoxy oxygen group content (EOC) of epoxidized soybean oil (ESO). Results showed that the enzymatic epoxidation of soybean oil can be enhanced using tetradecanoic acid (C₁₃H₂₇COOH) as active oxygen carrier and [Bmim]PF₆ as reaction medium. The optimum EOC of ESO was 5.9 ± 0.3% under the following conditions: reaction temperature 46°C, reaction time 11 h, enzyme load 3% (w/w, relative to the weight of soybean oil), molar ratio of H₂O₂/C=C-bonds 1.8:1, and molar ratio of C₁₃H₂₇COOH/C=C-bonds 0.5:1.