Title : Oxidative desulfurization of diesel fuel catalyzed by carbon supported polyoxometalates
Abstract:
Due to increasingly strict environmental regulations, further reduction of sulfur content in transportation fuels is a challenging task. Hydrodesulfurization (HDS) is the most widely used technology for removing sulfur from diesel fuels, which is usually operated at high temperature (300-400 oC) and pressure (30-130 atm) using alumina-supported Co-Mo or Ni-Mo sulfided oxides as catalysts. The main drawbacks of HDS are severe operating conditions and low desulfurization efficiency in the case of refractory benzothiophenes. Oxidative desulfurization is a promising method for removing refractory aromatic sulfur compounds. Typically, it involves liquid-phase biphasic oxidation of organosulfur compounds with H2O2 at 60 oC and atmospheric pressure to yield sulfoxides and sulfones, which can be separated from the fuel by precipitation, extraction or adsorption. This work demonstrates that Keggin-type polyoxometalates (POM) supported on activated carbon, POM/C, are effective solid catalysts for oxidative desulfurization of diesel fuel under mild conditions in a biphasic system composed of a model diesel fuel (heptane) and aqueous 27.9% H2O2.
