Sustainable Biodiesel Production from Sawdust Oil Using Snail Shell-Derived Bio-Catalyst

This study investigated the production of biodiesel from sawdust oil using a snail shell-derived calcium oxide (CaO) catalyst. The objectives were to extract and characterize oil from sawdust, synthesize and analyze a bio-based catalyst, and evaluate the properties of the biodiesel produced. Oil extraction was carried out with n-hexane, yielding 32%, which was higher than some conventional oilseeds. The extracted oil showed a pH of 6.6, density of 0.83 g/cm³, viscosity of 4.30 mm²/s, and a flash point of 133°C, indicating its suitability as a biodiesel feedstock. Snail shells were calcined at 900°C and characterized by X-ray diffraction, confirming CaO as the dominant phase. Transesterification of the oil with ethanol in the presence of the catalyst produced biodiesel that was analyzed for physicochemical properties and fatty acid composition. The biodiesel exhibited a viscosity of 2.43 mm²/s, acid value of 0.29 mg KOH/g, cetane number of 51, and flash point of 14700B0C, all within ASTM standards. GC–MS analysis revealed 17.8% saturated and 79.8% unsaturated fatty acids, providing a balance of oxidative stability and cold-flow performance. Overall, the study demonstrates that sawdust oil and snail shell-derived CaO are viable, low-cost, and sustainable materials for biodiesel production. It is recommended that further optimization of catalyst loading and reaction parameters be carried out to enhance fuel properties and promote large-scale application.