Application of green synthesis nanocomposite adsorbents in the adsorption desulfurization of dibenzothiophene in model oil

The nanocomposites have an important role in accelerating the adsorption of sulfur compounds because of their improved chemical and mechanical characteristics. In this study, silver nanoparticles, zinc oxide nanoparticles, and silver/zinc oxide nanoparticles were greenly synthesized and loaded with activated carbon by a successive precipitation method for the adsorptive desulfurization of model oil (dibenzothiophene, DBT, in 85% hexane + 15% toluene). The obtained adsorbents were characterized by using UV-visible spectroscopy, Fourier transmission infrared spectroscopy, a field emission scanning electron microscope, energy-dispersive X-ray spectroscopy, X-ray diffraction, and Brunauer-Emmett-Teller surface area (S_BET) analysis to confirm their structure, chemical composition, functional groups present on the adsorbents, and surface area. The adsorption experiments were conducted under optimal conditions, with 0.15 g of adsorbent dosage and a contact time of 1 h at 25 °C, during which the (Ag/ZnONPS-AC) adsorbent removed 99% of dibenzothiophene (250 mg/l). The total order removal performance of DBT of: Ag/ZnONPS-AC > ZnONPS-AC > AgNPS-AC > AC was observed. Kinetic studies revealed that the adsorption process of (Ag/ZnONPS-AC) obeyed pseudo-second-order kinetics and the Langmuir adsorption isotherm model. This study provides a cost-effective adsorbent for the effective desulfurization of model oil.