Kinetics of Sulfur Removal from Tehran Vehicular Gasoline by g-C3N4/SnO2 Nanocomposite

Abstract

The graphitic carbon nitride/tin oxide (g-C3N4/SnO2) nanocomposite synthesized under microwave irradiation was used for adsorptive removal of sulfur-containing dibenzothiophene (DBT) from Tehran vehicular gasoline. High-resolution transmission electron microscopy, X-ray powder diffraction, energy dispersive X-ray spectroscopy, Brunauer-Emmett-Teller, Fourier-transform infrared spectroscopy, and field emission scanning electron microscopy techniques determined the adsorbent characteristics, and gas chromatography with a flame ionization detector determined the DBT concentration of the samples. Application of the experimental data into the solid/fluid kinetic models indicated a chemisorption control regime that increased the removal of sulfur from the commercial samples used. A pseudo-second-order reaction with the rate constant of 0.015 (g mg-1 min-1) and total conversion time of 316 min described the adsorption process. Based on the real fuel results, the adsorption capacity of the g-C3N4/SnO2 adsorbent reached 10.64 mg S g-1 adsorbent at equilibrium conditions. This value was the highest adsorption capacity obtained so far for a commercial gasoline sample. The g-C3N4/SnO2 nanocomposite could, therefore, be introduced as an inexpensive, easily obtainable adsorbent that can significantly remove the sulfur from the vehicular gasoline fuels.