Transesterification of Soybean Oil through Different Homogeneous Catalysts: Kinetic Study

The search for alternatives to fossil fuels has been widely covered, especially in the past two decades. Thus, the role of biodiesel has been important, and its implementation in biorefineries seems feasible due to the sustainability of the process. This way, the knowledge of kinetics is vital to design industrial facilities and to compare the efficiency of catalysts (both typical and innovative ones) during transesterification or other similar processes taking place in a biorefinery, such as biolubricant production through transesterification with superior alcohols. In this work, a thorough kinetic study of homogeneous catalysts (base catalysts, such as KOH, NaOH or CH3OK, and acid catalysts (H2SO4, H3PO4 and p-toluenesulfonic acid, CH3C6H4SO3H)) applied to the transesterification of soybean oil was carried out to provide extensive kinetic data about this process. As a conclusion, a pseudo-first-order reaction mechanism was applied in all cases, with activation energies of 65.5–66 and 92.3 kJ·mol−1 for KOH and CH3C6H4SO3H, respectively, proving the higher activation energy for acid catalysis compared to base catalysis.