Potency of papaya leaf as green catalyst in biodiesel synthesis for transesterification of coconut oil

Abstract

Abstract Papaya leaf is a promising biomass to be developed into a green catalyst for biodiesel synthesis. This study aimed to evaluate the potential of papaya leaves by calcination at 700°C for 3 hours, and to assess the created papaya leaf ash as a catalyst in biodiesel transesterification. Characterization of papaya leaf ash was carried out using SEM-EDX and FTIR. The results confirmed that papaya leaf ash contains metal oxides such as K2O, MgO and CaO which function as active components that catalyse the reaction. Transesterification of coconut oil was carried out at fixed molar ratio of oil to methanol (OTM) of 1:12, reaction temperature of 55-65°C, and catalyst load of 2-4wt.%. The highest yield of biodiesel was 97.36% with a purity of 99.39%. It was obtained at reaction temperature of 60°C, 3% catalyst load, and 150 min reaction time. The quality of biodiesel obtained was correspondent to European standards (EU 14214). The results confirm that papaya leaf ash may be used as a heterogeneous catalyst in the manufacture of biodiesel.