Study of the Process Parameters of the Canola Oil Epoxidation

Abstract

Canola oil was epoxidized in situ with peracetic acid in the presence of an ion exchange resin catalyst. A two-level fractional factorial design was used to determine the effect of five parameters on the conversion of double bonds to epoxy groups: (A) molar ratio of acetic acid to double bonds, (B) molar ratio of hydrogen peroxide to double bonds, (C) concentration of hydrogen peroxide, (D) concentration of catalyst, and (E) temperature. The yield of epoxidized oil in the presence of toluene was evaluated in a separate experiment. Iodine value and oxirane oxygen content, which express the presence of double bonds and epoxy groups respectively, were evaluated and characterized by FTIR spectroscopy. The analysis of variance (ANOVA) for oxirane content identified the parameters A, C, E and the interactions AC, AE, and CE statistically significant at p<0.05 with a coefficient of determination of 0.82. The analytical determinations were confirmed by FTIR spectroscopy showing that samples with lower iodine values had higher oxirane oxygen content. The highest conversion of double bonds to epoxy groups (6.5 %) was achieved at acetic acid: hydrogen peroxide (50%): double bonds molar ratio of 0.5:2:1, catalyst concentration of 25% at 60°C. The presence of toluene did not affect the conversion of double bonds to epoxy groups, but increased the yield from 80% to 90% (90g epoxidized canola oil/100 g canola oil).