Transesterification of Waste Cooking Oil Utilizing Potassium Doped Empty Fruit Bunches Ash Heterogeneous Catalyst

Abstract

The growing demand for fossil fuels has prompted the exploration of alternative sustainable energy sources like biodiesel, renowned for its renewable nature and eco-friendliness. Empty fruit bunch ash (EFBA) has attracted significant interest due to its composition of various metal oxides, making it a promising option for creating high-performance heterogeneous catalysts. The synthesis of EFBA involves the co-precipitation method, where it is activated by KOH catalyst, denoted to as K/EFBA. This method enables the metal oxides in EFBA to bond with KOH, forming a catalyst with mixed metal oxides that enhances catalytic efficiency and prevents the loss of active sites. The K/EFBA catalyst exhibits a robust basicity of 2215.05 μmol/g, with more active sites resulting from the interaction of metal oxides, capable of converting waste cooking oil (WCO) into fatty acid methyl esters (FAME). Optimal conditions for transesterification of WCO, including a 7 wt% catalyst loading, 45 minutes reaction time, and a 12:1 methanol to oil ratio, yielded a biodiesel output of 70.51%. Gas chromatography-mass spectrometry (GCMS) analysis identified six peaks corresponding to different FAME groups, such as lauric acid methyl ester, myristic acid methyl ester, palmitic acid methyl ester, oleic acid methyl ester, and linoleic acid methyl ester. These results underscore the potential of the K/EFBA catalyst in converting WCO into biodiesel.