Production of waste vegetable oil biodiesel using calcined periwinkle shells as catalyst

As part of the efforts in overcoming global energy crisis, this research work focuses on the transesterification of waste vegetable oil, using calcined periwinkle shells and wet impregnated zinc oxide as catalysts. Periwinkle shells were calcined at 850 °C for 3 h, using carbolite furnace to obtain CaO catalyst and part of the catalyst was wet impregnated with ZnO. The quality of the calcined CaO obtained (81.6%) was established through XRF analysis. The three parameters considered during the transesterification of the treated waste oil were methanol/oil ratio (0.2–0.8 v/v), catalyst concentration (4–8 wt/wt%) and reaction time (1–2 h). At methanol/oil ratio of 0.34 v/v, catalyst concentration of 4.12 wt/wt% and reaction time of 2 h, the optimum biodiesel yield of 84.96% was obtained using calcined CaO catalyst and a yield of 81.33% using impregnated ZnO/CaO catalyst. Brake power of 4.47 kW was obtained for both the biodiesel produced and pure diesel standard. Other mechanical properties, physical properties, as well as the chemical composition of the biodiesel produced revealed high level of conformity of the biodiesel produced to ASTM standards.