Epoxidation of crambe seed oil with peracetic acid formed in situ

Abstract

AbstractThis study investigated the epoxidation of crambe seed oil (CSO) using peracetic acid formed in situ during the reaction process. First, a preliminary study of the main operational variables was carried out. Then, the kinetic behavior of the reaction was verified, evaluating the effect of the molar ratio of hydrogen peroxide to ethylenic unsaturation, catalyst percentage and temperature. The results indicate that the smallest amount of hydrogen peroxide (1.1 mol mol−1) favors the relative conversion to oxygen oxirane (RCO) and that an increase in the catalyst percentage up to 2.4 wt% intensifies the reaction, maintaining the stability of the process. In addition, the reaction carried out at high temperatures results in greater conversions in short time, however, it is necessary that the reaction is stopped at the exact time, avoiding exceeding the formation of epoxy resulting in the obtaining of by‐products. Some unsaturated fatty acids are partially consumed while others (linolenic and gondoic acid) are completely consumed during the entire reaction. The epoxidized oils showed higher viscosities in relation to the CSO. The FTIR spectra indicated the appearance of the epoxide group and the analysis by gas chromatography coupled to a mass spectrometer indicated the formation of two epoxidized compounds, 3‐octyl oxirane octanoic acid and 10‐oxo‐octadecanoic acid methyl ester. The highest efficiency for the formation of CSO epoxides, within the ranges of the variables evaluated, was observed at 80°C, 8 h reaction, using a H2O2 to CC molar ratio of 1.1 mol mol−1 and 2.4 wt% H2SO4.