Binary metal oxides supported on gamma-Al2O3 for application in transesterification of low-grade cooking oil

Abstract

Recently, the production of biodiesel has increased greatly due to the less harmful effects of this fuel towards the environment which is sourced from renewable materials compared to a conventional diesel. The series of solid base catalysts, binary metal oxide (Cu/Zn) were synthesized by the modified wet impregnation method supported on γ-Al2O3.The investigation of Cu/Zn/γ-Al2O3 catalyst on the calcination temperature, copper loading and number of alumina coatings had significantly affected the catalytic performance. The optimum conditions from experimental data were achieved with 10 wt.% of Cu loading of Cu/Zn/γ-Al2O3 catalyst calcined at 800°C with 3 times number of alumina coatings exhibited the highest fatty acid methyl ester (FAME) yields, 87.07% at mild reaction conditions (65°C, atmospheric pressure, 1:20 methanol-to-oil molar ratio, 10 wt.% of catalyst loading and 2 hours of reaction time). The physicochemical properties studied by BET surface area of Cu/Zn(10:90)/γ-Al2O3 catalyst calcined at 800°C which gave high surface area, 149.32 m2/g. FESEM-EDX analysis of Cu/Zn(10:90)/γ-Al2O3 catalyst indicated the amorphous in structure with undefined shapes and mixture of larger and smaller particles sizes. The production of biodiesel and the percentage conversion of FAME was analyzed by using GC-FID in the presence of methyl palmitate, cis-9-oleic acid methyl ester and methyl linoleate.