Heterogeneous calcium-based bimetallic oxide catalyzed transesterification of Elaeis guineensis derived triglycerides for biodiesel production

[Display omitted] •High grade biodiesel was synthesized from E. guineensis derived triglycerides.•Enhanced the catalytic activity by synergistic effects.•Catalyst with highly amount of basicity (750μmolg−1) was prepared.•The FAME yield of >99% was achieved at the best reaction conditions.•The catalysts had good recoverability and strong ability to reuse for 5 cycles. Calcium-based mixed metal oxides were synthesized via co-precipitation process and investigated as catalysts for biodiesel production. Calcium was added into bulk oxide system in order to increase their basicity and, consequently, improved its performance in the transesterification of Elaeis guineensis oil with methanol. The Ca:Mg ratio used in the preparation was varied in order to define the best concentration of calcium and magnesium leading to solids with ideal morphology (interaction of Ca–O–Mg binary system) and improved calcium loading. Synthesized catalysts were characterized by powder X-ray diffraction (XRD), thermogravimetric/derivative thermogravimetric analysis (TG/DTG), reflection-Fourier transform-infrared (FTIR), N2 physisorption, CO2 temperature-programmed desorption (CO2-TPD), scanning electron microscopy (SEM). Obtained results demonstrated that the optimal Ca:Mg ratio was 1:1. It was found that mixed solid bases oxides demonstrated high basicity and stability. Mixed CaO–MgO (CM-1.0) catalyst showed higher amount of medium and strong basic sites than other mixed and pure oxide (as areference) catalysts, respectively during the transesterification reaction. It was found that the catalytic activity of catalysts were arranged in the sequence of: CaO>CM-1.0>CM-0.5>CM-2.0>MgO. The highest conversion of Elaeis guineensis derived triglycerides to methyl esters was achieved at 99% with 4wt.% of CM-1.0 catalyst at 60°C and 6h time. Recyclability tests suggested that this catalyst could be recycled for five successive runs without significant loss in catalytic activity.