Investigation of Oxidative Desulfurization of Light Naphtha by NiMo/-Al2O3 Catalyst

Abstract

In this research, we investigated the effects of parameters, including reaction time, reaction temperature, the mass ratio (mcat./mfeed), and volume ratio (VH2O2/Vfeed) on sulfur removal conversion of light naphtha under oxidative desulfurization (ODS) reaction. So to achieve this goal, several active catalysts are prepared while molybdenum (Mo) was used as an active metal. Nickel (Ni) was the promoter. 𝛾-alumina (𝛾-Al2O3) was used as a support and modified by chelate agents such as citric acid (C6H8O7), ethylene diamine tetraacetic acid (EDTA), polyethylene glycol (PEG), Sorbitol, and urea ((NH4)2CO). These catalysts were synthesized by using the wetness impregnation in-situ method. Then they were applied to the ODS process for light naphtha. These catalysts were characterized by N2adsorption-desorption isotherms (BET, BJH), Scanning Electron Microscope (SEM), temperature-programmed desorption (NH3-TPD), and FT-IR analysis. The catalyst that synthesized in the presence of sorbitol, had the best performance.  The optimization conditions for this catalyst were m (catalyst)/m (feed)= 0.013, reaction temperature of 35 °C, 50 mL of feed, 0.5 g of catalyst, 1 hour reaction time, and V (H2O2)/VFeed = 0.045.  It revealed the maximum performance for ODS reaction of the real feed. Under these circumstances, the sulfur of light naphtha decreased from 160 ppm to 38 ppm during the reaction.