Biodiesel production from Hevea brasiliensis oil using SO3H-MCM-41 catalyst

Abstract The use of Hevea brasiliensis oil (para rubber seed oil) as a biodiesel feedstock was achieved under high pressure in an autoclave reactor using a methyl propyl sulfonic acid-functionalised MCM-41 catalyst (SO 3 H-MCM-41). Four experimental parameters, namely catalyst loading, reaction time, reaction temperature, and the molar composition of 3-mercaptopropyl(methyl)dimethoxysiloxane, were investigated using the Box–Behnken design. The optimisation model showed good statistical reliability, with a linear correlation coefficient close to 1. Under the optimum reaction conditions (5.06 wt% catalyst loading, 120 min, 153 °C, and 0.266 of MPMDS molar composition), the highest predicted and experimental fatty acid methyl ester yields were 96.6% and 95.5%, respectively. The catalyst was benchmarked against a commercial homogeneous catalyst (H 2 SO 4 ) and proven to be more effective. Moreover, the catalyst could be reused up to four cycles under the optimum reaction conditions without significant loss of product yield.