Desulfurization of gasoline by a new method of electrochemical catalytic oxidation

A new deep desulfurization process for gasoline was obtained by means of electrochemical catalytic oxidation with an electrochemical fluidized-bed reactor on particle group anode. The particle group anode was activated carbon-supported cerium dioxide (CeO2/C), and the electrolyte was aqueous cerium nitrate solution, and copper pillar was cathode in the electrochemical reactions. The CeO2/C particle group anode could remarkably accelerate the electrochemical reaction rate and promote the electrochemical catalysis performance for the electrochemical desulfurization reaction. Thermodynamics feasibility analysis clarified that the theoretical decomposition voltage ranged from 0.1–0.5 V in pure acid electrolyte system and desulfurization reactions could not spontaneously carry out, but the reactions were spontaneous when aqueous cerium nitrate solution serves as electrolyte. And the rule of the gasoline desulfurization by the means of electrochemical catalytic oxidation was investigated. The experimental results indicated that the optimal desulfurization conditions were as follows: the cell voltage, concentration of the Ce3+ ions, feed volume flow rate and the CeO2 percentage by weight were 3.2 V, 0.08 mol l−1, 300 ml min−1 and 5.0 wt%, respectively. Under these conditions the concentration of sulfur in gasoline was reduced from 310 to 50 parts per million by weight (ppmw). Based on these experimental results, a mechanism of indirect electrochemical oxidation was also proposed.