Adsorptive desulfurization of metal phthalocyanine functionalized poly-ionic liquids grafted to silica gel

Four metal phthalocyanines (Pc-4, 8, 12, 16) functionalized ionic liquids were polymerized on the surface of silica gel as adsorbent materials. They were characterized by FT-IR, BET, SEM and TEM measurements. The characterization results proved that the adsorbents were prepared successfully. Their adsorptive desulfurization performances to dibenzothiophene in model oil at room temperature and atmospheric pressure were investigated in detail. The results showed that the adsorptive desulfurization effect of P-4 was best. The optimal amount of adsorbent was 10 g/100 mL model oil. The maximum amount of DBT adsorbed was 52.41 mg/g, superior to some previously reported adsorbents. The adsorption equilibrium and kinetics of this adsorbent were also examined. The adsorption behavior fitted well to Freundlich isotherm model, pseudo-second-order kinetics model and Weber and Morris kinetics model. Adsorption and regeneration by solvent processes were performed 10 times, and the adsorption capacity of the adsorbent did not decrease obviously. P-4 also had a good adsorption effect on different sulfur compounds, and the order of removal was DBT > BT > 2-MTH > TH.