Biodiesel production from crude palm oil under subcritical methanol conditions: Experimental investigation and kinetic model

Subcritical methanol approach is an environmentally benign method to produce biodiesel owing to no wastewater and soap formation during the process. However, biodiesel production from low-cost feedstock, i.e., crude palm oil (CPO) under subcritical methanol conditions, has not been evaluated well. Hence, this study aims to investigate a subcritical methanol technique for biodiesel production from CPO. Transesterification was performed using a batch reaction vessel under varied temperatures (160–200 °C), catalyst loadings (0.25–0.75 wt%), methanol-to-CPO molar ratios (5:1–30:1), and reaction times (10–60 min). The result showed that a biodiesel yield of 91.41 % was obtained at 180 °C within 50 min. The reaction kinetics of the transesterification process under subcritical methanol conditions was also deduced, and the reaction was observed to obey Arrhenius's behavior. The developed kinetic model was observed to fit the experimental data well.