Integrated oxidative-adsorptive desulfurization of model and real fuel oils over a Zn-impregnated hydroxyapatite-activated carbon (Zn/HA-AC) composite

Herein, a Zn-impregnated hydroxyapatite-activated carbon (Zn/HA-AC) composite catalyst was fabricated and was, in turn, applied for the desulfurization of a model and real oil samples via the integrated adsorptive-oxidative desulfurization strategy. Activity results revealed that Zn/HA and AC (25:75) realized 76.7% dibenzothiophene (DBT) adsorptive desulfurization at 50 °C in 60 min reaction time at an adsorbent dose of 0.14 g/20 mL of feed. Zn/HA-AC(25:75) composite catalyst was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray analysis, and scanning electron microscopy analysis. In the oxidative desulfurization (ODS) combined with adsorptive desulfurization experiments, under the optimum conditions of 45 ^oC temperature for 60 min and a catalyst dose of 0.1 g/20 mL of feed using H₂O₂ and HCOOH, Zn/HA-AC (25:75) achieved 93% DBT conversion. Under these optimized experimental parameters, the adsorptive desulfurization and catalytic ODS performance (% DBT conversion) of Zn/HA-AC (25:75) for real gasoline, kerosene, and diesel oil reached 18, 31 and 15%, and 31.66, 55.31 and 11.19%, respectively. Contrary to this, under the integrated catalytic-oxidative-adsorptive experiments, the desulfurization performance of Zn/HA-AC (25:75) for gasoline, kerosene, and diesel oil reached 61, 41, and 34%, respectively.