Partial Hydrogenation of Jatropha Oil Biodiesel Catalyzed by Nickel/Bentonite Catalyst

Abstract

The low oxidative stability of first generation biodiesel is one of the most important challenges to be overcome in biodiesel technology. A nickel/bentonite catalyst was prepared and applied in partial hydrogenation of Jatropha oil biodiesel for improving the oxidative stability of biodiesel. The catalyst was characterized by N2 adsorption–desorption, inductively coupled plasma-atomic emission spectrometer (ICP-AES), thermogravimetry-differential scanning calorimetry (TG-DSC), and transmission electron microscope (TEM). The main reaction parameters of partial hydrogenation such as reaction temperature, catalyst dosage, reaction pressure, stirring rate and reaction time were optimized. The mass conversion ratio of C18:2 up to 75% at the optimized hydrogenation conditions, and for the hydrogenated biodiesel, the contents of C18:2, c-C18:1, t-C18:1 and C18:0 were 7.64, 42.7, 24.06 and 14.67 wt%, respectively. After partial hydrogenation, the oxidative stability of hydrogenated biodiesel significantly increased from 6.5 h of feed Jatropha oil biodiesel to 18.0 h. The nickel/bentonite catalyst was recovered and reused for five consecutive cycles without any significant loss of the catalytic activity. Overall, via partial hydrogenation, the oxidative stability of biodiesel could be significantly provided using this effective nickel/bentonite catalyst. A bentonite-based nickel catalyst was prepared and used in partial hydrogenation of Jatropha oil biodiesel