Selective production of diesel-like alkanes via Neem seed oil hydrodeoxygenation over Ni/MgSiO3 catalyst

Abstract

In this research, catalytic hydrodeoxygenation (HDO) of Neem seed oil (NSO) over industrial Ni/MgSiO3 catalyst was investigated in batch reactor at 200–325 °C, 4–12 bar, and reaction time in the range of 60–300 min. The key issues of cost-effectiveness, high deoxygenation efficiency, and selectivity have been addressed. The effect of the operational parameters on yield and selectivity towards diesel-like alkanes (C11–C18) was explored. According to the results, the optimum reaction condition was 300 °C and 8 bar for 180 min, under which the diesel-like alkanes yield was 72.34%. Examination of the reaction mechanism revealed that the reaction progressed in the decarboxylation (DCO2) path and in almost all experiments performed the selectivity of the reaction towards the products obtained from this route. Also, effect of catalyst loading was investigated at optimum condition. In an interesting result, diesel-like alkanes yield was achieved to 98.60% with 20% catalyst loading. Catalyst efficiency and stability evaluated at optimum condition. In the initial four cycles, the catalyst displayed good activity and stability with almost constant alkane yields, but in the subsequent cycles, the catalyst's efficiency decreased.