In this study soybean FAME was employed to analyze in detail the epoxidation reaction network when performic acid (PFA) is used as oxygen carrier. The epoxidation reaction and the parallel, deleterious reactions linked to the oxirane ring-opening. The influence of several process variables (viz., degree of mixing, temperature, mol ratio of FAME double bonds/hydrogen peroxide/formic acid and solvent addition) on the system was studied, seeking reaction conditions capable of achieving high epoxide yields. Concentrated H2O2 (60 wt%) was used throughout the study. Also, the relevant kinetic rate constants pertaining to this reacting system were found.
The reaction temperature has a high impact in the yield and selectivity of the system, but employing 40 ºC it is possible to achieve high conversions and high yield as well. The epoxide yield is a strong function of the available amount of FA in the system. Formic acid is indeed crucial for producing enough PFA in the aqueous phase –which then passes to the organic phase to deliver an oxygen atom to the double bonds- but, also, is the main responsible for the opening of the oxirane rings. Also the H2O2-to-double bonds molar ratio was found to decrease the oxirane selectivity by ring-opening as said molar ratio was increased.