BIODIESEL

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.

This study investigated the production of biodiesel from waste cooking oil using a catalyst derived from chicken manure impregnated with nickel sulfate. The catalyst was prepared by calcining chicken manure followed by a sol-gel process to incorporate nickel, and characterizedas a porous material with a surface area of 115 m²/g. Using Response Surface Methodology, the reaction conditions were optimized, identifying a methanol-to-oil ratio of 12:1, 3% catalyst loading, 55°C temperature, and 90 minutes reaction time as optimal, resulting in a biodiesel yield of 95.67%. The biodiesel met flash point safety standards but showed higher viscosity, density, and acid value than international fuel specifications, indicating the presence of residual free fatty acids that require pretreatment or purification. This work demonstrates that chicken manure can serve as a cost-effective catalyst precursor in converting waste cooking oil to biodiesel, promoting sustainable waste utilization and renewable energy production

This study explored the optimization of the microwave aided biodiesel production from neem oil with a bio-waste catalyst derived from cow bones and rice bran using central composite design, an experiment analysis on response surface model. The bio-waste catalyst was synthesized by the carbonization and sulphonation of rice bran to produce an acid precursor, while cow bones was calcined and treated with KOH to create the basic precursor. Both precursors were then impregnated using the wet-impregnation method. Also, a model was developed to simulate the process and examine the interactive effect of process input variables on neem oil biodiesel yield using the central composite approach. These inputs generated about 50 runs to be carried out with the catalyst using methanol under optimal conditions. In this study, we aimed to optimize biodiesel production from neem oil using a microwave- assisted process with a bifunctional heterogeneous catalyst synthesized from cow bones and rice bran. Oil characterization was carried out according to the ASTM standards, the catalyst failed to facilitate the transesterification reaction resulting in no biodiesel formation. Biodiesel production was carried out using sodium hydroxide which proved the viability of the oil and this outcome underscores the critical importance of proper catalyst synthesis and activation in biodiesel production. Additionally, the presence of impurities or moisture during catalyst preparation could have led to deactivation, further inhibiting the reaction. Fresh catalyst samples have been impregnated and are awaiting analysis results