Production of biodiesel fuel by transesterification of different vegetable oils with methanol using Al2O3 modified MgZnO catalyst

► Versatile heterogeneous MgZnAlO catalyst used for synthesis of FAME. ► Catalyst shows high activity on different types of vegetable oils. ► Preparation procedure and treatment conditions resulted in stable composite oxide. ► Optimum conditions of FAME synthesis were determined for the oils. ► The catalyst has good recoverability and able to use in five successive cycles with stable conversions. An active heterogeneous Al2O3 modified MgZnO (MgZnAlO) catalyst was prepared and the catalytic activity was investigated for the transesterification of different vegetable oils (refined palm oil, waste cooking palm oil, palm kernel oil and coconut oil) with methanol to produce biodiesel. The catalyst was characterized by using X-ray diffraction, Fourier transform infrared spectra, thermo gravimetric and differential thermal analysis to ascertain its versatility. Effects of important reaction parameters such as methanol to oil molar ratio, catalyst dosage, reaction temperature and reaction time on oil conversion were examined. Within the range of studied variability, the suitable transesterification conditions (methanol/oil ratio 16:1, catalyst loading 3.32 wt.%, reaction time 6h, temperature 182°C), the oil conversion of 98% could be achieved with reference to coconut oil in a single stage. The catalyst can be easily recovered and reused for five cycles without significant deactivation.