Sunlight-driven photocatalytic production of biodiesel from palm oil utilizing a solid catalyst composed of a blend of CaO and Zn

Biodiesel, a promising eco-friendly substitute for petro-diesel, can be efficiently derived from abundant vegetable oils. Among these, palm oil stands out as a prime choice. A transesterification reaction was conducted on palm oil triglycerides with methanol catalyzed by CaO/ZnO blend. CaO serves as strong basic sites which are necessity for activation of methanol as well as triglycerides, whereas ZnO, a type of semiconductor, can absorb sunlight to form electron-hole pairs, thus the photocatalytic efficiency is greatly improved. This effect may reduce the activation energy and hence speeding up the reaction rate.  While conventional methods utilize caustic alkalis as catalysts for oil trans-esterification, issues such as unwanted soap formation and reduced biodiesel yield arise with homogeneous alkaline catalysts. This study represents into an innovative approach using a heterogeneous catalyst mixture of CaO and ZnO activated under sunlight to produce biodiesel from waste palm oil and methanol. The study shows that 94% yield of FAME from waste palm oil used as cooking oil using various concentration of catalyst mixture which is sunlight driven.  The effect of light, temperature and molar ratio on yield of biodiesel has also been studied in this present study. According to the results of the study, the highest yield of Biodiesel was obtained at 0.5 % catalysts concentration under sunlight at a 1:5 molar ratio. The optimum temperature for obtaining highest yield that has observed is 60˚C. In addition to , it has also been observed that increased concentration of catalysts and lower molar ratio minimized the overall yield of the transesterification.