Introduction

 Oxides of sulfur and nitrogen are the main air pollutants that are also responsible for acid rain. Excessive sulfur content in petroleum fractions such as naphtha, in addition to causing air pollutants, can corrode tanks, reactors, pipes and fittings. Currently desulfurization is carried out using desulphurization catalysts adjacent to hydrogen; thus at a certain temperature and pressure, as well as a specific proportion of hydrogen, sulfur atoms convert to hydrogen sulfide. Catalysts based on γ–alumina are commonly used for desulphurization. Alumina has various applications including ceramic membranes, paints, refinery and chemical catalysts, pollution control and base catalyst. The mesoporous γ–alumina with pore diameter in the range of 2 to 50 nm due to its high specific surface area, high porosity, good thermal stability and suitable pore distribution is used as the most common base catalyst in desulphurization.