Modification of activated carbon with tetrafluoroboric acid and its performance in adsorption desulfurization of dibenzothiophene

The activated carbon adsorbent was modified with tetrafluoroboric acid (HBF₄) by impregnation and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and N₂ physisorption. The performance of modified activated carbon in adsorption desulfurization of dibenzothiophene (DBT) in model diesel fuel was investigated and the influences of HBF₄ concentration, calcination temperature and the initial DBT concentration on the sulfur removal efficiency were considered. The results show that the adsorbent modified with 0.5% HBF₄ solution and calcined at 140 ℃ performs best in DBT desulfurization; when the adsorbent/oil ratio is 1:100, the HBF₄-modified adsorbent exhibits an adsorption capacity of 352 mg/g, which is 72.5% higher than that of the unmodified activated carbon.