Reactive Characteristics and Adsorption Heat of Ni/ZnO–SiO₂–Al₂O₃ Adsorbent by Reactive Adsorption Desulfurization

Reactive adsorption desulfurization (RADS) experiments of fluid catalytic cracking (FCC) gasoline and a model gasoline over an Ni/ZnO–SiO 2 –Al 2 O 3 adsorbent were carried out in a fixed-fluidized bed reactor at low pressures in an H 2 atmosphere. The results show that hydrogenation, hydrogen transfer, and polymerization reactions accompany RADS. Sulfidation and carbon deposits, which can lead to decreases in the regeneration rate and amount of activated Ni, are crucial to the decay of desulfurization and the olefin-hydrogenation capability of the adsorbents. The obvious reduction of C 5 and C 6 olefins in FCC gasoline mainly contribute to the drop in octane number of the desulfurization product. The desulfurization experiment on model gasoline and the adsorption heats of model compounds show that RADS removes sulfur from sulfur-containing compound through S–M interactions rather than by π-complexation over the Ni/ZnO–SiO 2 –Al 2 O 3 adsorbent. The adsorption heat of sulfur-containing compound is proportional to the electron density of sulfur atoms.