Oxidative desulfurization of refinery diesel pool fractions using LaVO4 photocatalyst

Abstract

Oxidative desulfurization (ODS) is a swiftly rising organosulfur compounds eradicating system, effective enough at a mild temperature and pressure, overwhelming the necessity of costly hydrogen in the traditional HDS systems. In this study, pure LaVO4 photocatalyst was prepared using the hydrothermal approach and employed for deep oxidative desulfurization application in the aerobic environment under visible-light irradiations. The as-prepared photocatalyst semiconductor material was characterized by FTIR, SEM, UV–vis DRS and Raman analyses. The examined photocatalyst presented a narrow bandgap, a small particle size, high photo-responsive monoclinic phase, high light photons capturability, plenteous active sites accessibility and reduced recombination of photogenerated charge carriers, ensuing a good visible-light-driven deep oxidative desulfurization ability. The photocatalytic material was tested for its performance over different petroleum refinery diesel pool fraction streams including hydrodesulfurization unit diesel rundown, mild hydrocracking unit rundown gas oil, heavy kerosene oil and the ultimate diesel oil blend, containing organosulfur compounds ranging from disulfides to the stringent organosulfur compounds, with the quantity lying between 57 and 863ppm. The kinetic study was found in agreement with the pseudo-first-order kinetics. The conceivable desulfurization mechanism was also anticipated. Moreover, the recyclability of the photocatalytic material was also discussed.