The present work mainly focuses on the development of heterogeneous catalysts from fishbone, loaded with sodium hydroxide for transesterification of biodiesel. The catalyst was developed using a two-step process involving the calcination of fishbone at 900 °C, followed by a hydrothermal process with a sodium hydroxide-loaded (NaOH) solution. The synthesized heterogeneous catalyst was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and BET surface area analysis. The transesterification of waste cooking palm oil (WCO) with BC-NaOH shows a maximum yield of up to 98% for 2.5 wt.% catalyst loading, 1:9 oil:methanol molar ratio at a temperature of 65 °C for a reaction time of 1.5 h. The enhanced catalytic activity is due to the high base active site density of hydroxyl groups from hydroxyapatite, β- tricalcium phosphate, and sodium hydroxide. A gas chromatography-mass spectroscopy (GC-MS) was performed to determine the conversion of oil to biodiesel. The reusability of the catalyst was confirmed from the consistency in the biodiesel yield obtained in up to 7 cycles.
Keywords: Biodiesel; Heterogeneous catalyst; Hydroxyapatite; Transesterification; Waste cooking oil; Yield; β- tricalcium phosphate.