Transformation of Jatropha oil into green diesel over a new heteropolyacid catalyst

An environmentally friendly hydrocracking catalyst (Ni-H₃PW ₁₂O₄₀/Al₂O₃) was designed for generating green diesel from Jatropha oil in a clean process. The Ni-HPW/Al ₂O₃ (where HPW = H₃PW₁₂O ₄₀) catalyst was prepared by a two-step impregnation method and characterized using N₂ adsorption, X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy techniques. The catalytic assays were executed in a fixed-bed reactor, and the effects of the reaction parameters, i.e., temperature, hydrogen-to-oil ratio, and liquid hourly space velocity, on the conversion and reaction pathways were investigated. Of the evaluated reaction parameters, temperature played the most significant role in the selectivity of the reaction pathway. Nearly 97.8% conversion of Jatropha oil and 83.5% selectivity of the diesel fraction were obtained at a temperature of 360°C, and a pressure of 3.5 MPa, H₂/oil volume ratio of 500 Nm³ m^-3, and liquid hourly space velocity of 1.0 h ^-1. The developed Ni-H₃PW₁₂O ₄₀/Al₂O₃ catalyst is not only more environmentally friendly than conventional sulfided hydrocracking catalysts but also shows high activity and selectivity in the production of hydrocarbons in the diesel fuel range. Therefore, this catalyst may be a promising alternative for the production of green diesel. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 1240-1246, 2013