ADSORPTION of Aromatic Sulfur Molecules On Mesostructured Silica Adsorbents

Desulfurization of benzothiophene/isooctane mixtures and gasoline (42.5 ppmw S) was achieved by π-complexation adsorption with PdCl2 supported on the SBA-15 mesoporous material. PdCl2/SBA-15 sorbent was prepared with spontaneous monolayer dispersion of metal (Pd) onto the surface of SBA-15. SBA-15 and  PdCl2/SBA-15 were characterized with N2 physical adsorption. Desulfurization of benzothiophene/isooctane mixtures and gasoline (42.5 ppmw S) with these sorbents was investigated in batch and fixed bed. PdCl2/SBA-15 showed by far the highest capacity of sulfur adsorption. A simulation model was used to predict the breakthrough curves for adsorption and desorption runs. The spent PdCl2/SBA-15 was regenerated using isooctane as eluent, and the regenerated PdCl2/SBA-15 was tested again for the desulfurization. The results showed that about 98% of the sulfur capacity were recovered at breakthrough. PdCl2/SBA-15 seemed to be adequate for aromatics removal in this system.