Investigation of Mesoporous Y-Zeolites on Adsorptive Desulfurization of Model-Diesel Fuels

Combustion of commercial fuels, which contain a significant amount of sulfur, releases various amount of air pollutants such as SO_x. Hydrodesulfurization (HDS) is the conventional method being employed to remove the sulfur compounds. However, this method is very costly and demands severe operating conditions to meet the stringent sulfur standards set by the regulations. More importantly, HDS is highly energy intensive ( requires high hydrogen pressure) to remove the refractory sulfur compounds, such as alkyl-benzothiophene and its derivatives, commonly found in diesel fuels. Adsorptive desulfurization is a promising method of removing these compounds from fuels with low energy consumption and facile operating conditions. Zeolites are commonly used as adsorbents due to their high surface area and unique pore structure.  Mesoporous Y-Zeolites is prepared using desilication and surfactant reassembly methods. The hierarchical-sized pores within the zeolite framework would allow for heavier sulfur molecules to diffuse and adsorb on the active surface. Y-zeolites are also ion-exchanged with metal elements, such as Ce and Cu, to create metal-modified zeolites. These metal components bind the organic sulfur compounds strongly via the metal sulfide formation, thereafter increasing the capacity for sulfur adsorption. The results of our research study revealed that hierarchical zeolites and metal-modified zeolites can effectively improve the desulfurization performance.