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

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 K 2 O, 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.