Deep oxidative/adsorptive desulfurization of model diesel oil by DBD/FeCl3–SiO2

Oxidative/adsorptive desulfurization of model diesel oil by a dielectric barrier discharge (DBD) plasma in the presence of air as oxygen resource was studied. This new system exhibited excellent desulfurization effect at room temperature when FeCl3–SiO2 is used as catalyst and adsorbent. The sulfur content of DBT in model oil can be decreased from 200 ppm to 3 ppm (S-removal rate up to 98.4%) under optimum reaction conditions (air flow rate (υ), 90 ml/min; amplitude of applied voltage (U) on DBD, 30 kV; input frequency (f), 600 Hz; catalyst amount (ω), 3 wt%; the reaction time (t), 30 min). It is obvious that the DBD/FeCl3–SiO2 had better desulfurization ability than the DBD, FeCl3, and SiO2 were used alone. Moreover, the good desulfurization rate of BT (benzothiophene) and 4,6-DMDBT (4,6-dimethyl-dibenzothiophene) could reach 94.8% and 92.7% under the above conditions, and the sulfur removal selectivity for S-compounds followed the order of DBT > BT > 4,6-DMDBT.