Studies on adsorptive desulfurization by zirconia based adsorbents

This study reports usage of laboratory prepared zirconia samples (normal dried zirconia (ZD383), zirconia calcined at 893 K (ZC893), zirconia sulfated and calcined at 893 K (SZC893)) as adsorbents for the removal of sulfur from model oil (dibenzothiophene, DBT in iso-octane). Bulk densities of adsorbents were found to be in the range of 0.896-0.987 kg/m(3). Optimum adsorbent dose was found to be 10 g/l. The adsorption of DBT on zirconia based adsorbents was found to be gradual process with quasi-equilibrium condition reached in 22 h. Brunauer-Emmett-Teller (BET) isotherm best represented the equilibrium adsorption data. The heat of adsorption and change in entropy for DBT adsorption onto zirconia based adsorbents were found to be -165.3 (ZD383), -125.5 (ZC893), -96.7 (SZC893) kJ/mol, and -509.9 (ZD383), -379.4 (ZC893), -284.1 (SZC893) J/mol K, respectively. (C) 2011 Elsevier Ltd. All rights reserved.