Optimization of the Chemoenzymatic Epoxidation of Soybean Oil

The lipase Candida antarctica (Novozyme 435) immobilized on acrylic resin Was used as an unconventional catalyst for in situ epoxidation of soybean oil. The reactions were carried out in toluene. The peracid used for converting TG double bonds to oxirane groups was formed by reaction of FFA and hydrogen peroxide. The reaction conditions were optimized by varying the lipase concentration, solvent concentration, molar ratio of hydrogen peroxide to double bond, oleic acid concentration, and reaction temperature. The kinetic study showed that 100% conversion of double bonds to epoxides can be obtained after 4 h. The addition of free acids was not required for the reaction to proceed to conversions exceeding 801%, presumably owing to generation of FFA by hydrolysis of soybean oil. The enzyme catalyst was found to deteriorate after repeated runs.