Facile technique towards clean fuel production by upgrading waste cooking oil in the presence of a heterogeneous catalyst

Herein, we utilized waste triglycerides “cooking oil” as an abundant source for biodiesel (methyl esters) production via transesterification over a novel synthesized heterogeneous catalyst (Zn-MgO-ZrO₂). The catalyst was prepared by the co-precipitation technique and analyzed by using X-ray diffraction, Scanning Electron Microscope, temperature desorption analysis and surface analysis to better understand the surface chemistry of the catalyst. Moreover, the biodiesel production process through transesterification by using Zn-MgO-ZrO₂ was optimized. The optimal biodiesel yield was 92.3 wt% when the optimal set of process variables were at a temperature of 80 °C, molar ratio 12 (methanol and oil), time 4 h and catalyst amount was 4 wt%. The synthesized heterogeneous catalyst is reusable with almost equal efficiency as for the fresh catalyst. Different techniques also examined the quality of produced biodiesel according to the standard procedures defined by the American Society for Testing and Materials (ASTM) and European Union (EU) Standards.