Study and optimization of conditions of biodiesel production from edible oils using ZnO/BiFeO3 nano magnetic catalyst

In the present study, a magnetic ZnO/BiFeO3 was successfully prepared by co-precipitation method and applied as a cheap and novel magnetic nanocatalyst for the biodiesel production from canola oil through a transesterification reaction. The nanomagnetic catalyst was investigated by X-ray diffraction patterns (XRD), Fourier transforms infrared (FT-IR), CO2-Temperature programmed desorption (CO2-TPD) and scanning electron microscopy (SEM). In addition, the magnetic property of the catalyst was studied by vibrating sample magnetometer (VSM). It was demonstrated that ZnO/BiFeO3 with saturation magnetization (Ms) of 13.65 emu.g(-1) has super-paramagnetic behaviour at room temperature, and could be recovered by an external magnet for reuse. The optimum conditions for the process resulted in the molar ratio of methanol/canola oil of 15:1, a reaction temperature of 65 degrees C and a catalyst amount of 4 wt%, in which the conversion of canola oil was 95.43%. The catalyst was reused 5 times and, the FAME yield maintained more than 92.08% after 5 times. In agreement with Hammet method, CO2-TPD results indicated that the incorporation of ZnO onto BiFeO3 promoted the basicity of the catalyst leading to improve the catalyst activity in biodiesel production.