Fabrication of surface-modified dual waste-derived biochar for biodiesel production by microwave-assisted esterification of oleic acid: Optimization, kinetics, and mechanistic studies

The dual bamboo and coconut waste-derived catalyst was utilized to enhance the esterification reaction between two incompressible reactants, (oleic acid and methanol), to increase the mass transfer, which further decreased the reaction time and energy. The comparison study of the sulfonated dual waste biochar (DWBS) with single biomass-derived catalysts, sulfonated bamboo biochar (BBS), and sulfonated coconut husk biochar (CHBS) shows that the DWBS catalyst efficiently produces biodiesel by esterification reaction under optimum conditions. The catalyst significantly reduces activation energy to a greater extent, with a value of 32.32 kJ/mol as compared to BBS and CHBS catalysts. The reusability study reveals that the DWBS catalyst is effective for up to six cycles, demonstrating the catalyst's remarkable stability. The results indicate that the DWBS catalyst could be used for biodiesel production with low catalyst loading and a high reaction rate.