Characteristics of sulfur removal by silver-titania adsorbents at ambient conditions

Sulfur capacity of SiO2, TiO2 and γ-Al2O3 structures was investigated. Thermal treatment of TiO2 and γ-Al2O3 in air increased their respective sulfur capacity by 67 and 43%. Sulfur capacity was associated with surface acidity and the improvement attributed to the formation of bronsted acid sites. Addition of 4wt% transition metals further enhanced the sulfur capacity of TiO2 with Ag indicating the highest increase. Comparison of sulfur capacity of Ag/TiO2 with other adsorbents was made using JP5 fuel with sulfur concentration of 1172 ppmw. Ag/TiO2 adsorbent demonstrated a saturation sulfur capacity of 8.20 mg/g. A significant loss in sulfur capacity was observed between real and model fuel compositions. Various factors resulting in this loss was investigated such as the effect of additives, competitive adsorption and the structure of sulfur heterocycles.