COW BONE

This study focuses on the production of biodiesel from waste cooking oil (WCO) using calcined cow bone as a heterogeneous catalyst through the transesterification process. The research aimed to promote sustainable energy production by converting waste oils into biodiesel while utilizing animal bone waste as a low-cost, environmentally friendly catalyst. The WCO was pretreated and characterized to determine its physiochemical properties, which included an acid value of 1.4025 mg KOH/g, free fatty acid (FFA) content of 0.7012%, peroxide value of 16 meq/kg, iodine value of 44.1 g I₂/100 g, viscosity at 40 °C of 53.5 cP, saponification value of 362.667 mg KOH/g, moisture content of 2.678%, and density of 0.9176 g/cm³. These results confirmed that the feedstock required pretreatment before transesterification to minimize soap formation and enhance biodiesel yield. Characterization of the catalyst was performed using analytical techniques such as X-ray fluorescence (XRF), Brunauer–Emmett–Teller (BET) surface area analysis, and Fourier transform infrared spectroscopy (FTIR) to confirm the presence of CaO and evaluate its surface properties.The transesterification reaction was carried out using methanol and cow bone-derived catalyst under optimized conditions. The resulting biodiesel was washed, purified, and analyzed for key physiochemical properties. The biodiesel exhibited an acid value of 0.561 mg KOH/g, density of 0.901 g/cm³, viscosity at 40 °C of 8.86 cP, and a flash point of 115 °C. These results were within acceptable limits prescribed by ASTM D6751 and EN 14214 standards, indicating that the produced biodiesel possesses good fuel properties suitable for use in diesel engines. The study concludes that waste cooking oil can serve as an efficient feedstock for biodiesel production, and cow bone ash is a promising, sustainable, and economical catalyst. This dual utilization of waste materials not only reduces environmental pollution but also supports circular economy practices and sustainable energy development.