Equilibrium, Kinetic, and Thermodynamic Studies on Adsorptive Desulfurization onto CuICeIvY Zeolite

The (CuY)-Y-I, (CeY)-Y-IV, and (CuCeY)-Ce-I-Y-IV zeolites were successfully prepared and the competive adsorptions of toluene, cyclohexene, and pyridine were investigated. The results indicate that the effects on the metal ion-exchanged Y zeolites for sulfur removal decrease in the order pyridine > cyclohexene > toluene. The (CuCeY)-Ce-I-Y-IV not only has high sulfur adsorption capacity, similar to (CuY)-Y-I, but also has high selectivity for sulfur compounds, similar to (CeY)-Y-IV. The isotherms and kinetics of benzothiophene (BT) adsorption from 1-octane onto (CuCeY)-Ce-I-Y-IV were studied, and the thermodynamic parameters (Delta G, Delta H, Delta S) for the adsorption of BT were calculated. The results show that the isothermal equilibrium can be represented by the Langmuir model and that maximum adsorption capacities (q(m)) increase with an increase of temperature. The kinetics for the adsorption process can be described by either the Langmuir model or a pseudo-first-order model. The adsorption is spontaneous and exothermic.