| abstract |
Sulfur-containing compounds, including specifically thiophenic compounds, in a liquid hydrocarbon feedstream are catalytically oxidized by combining the hydrocarbon feedstream with a catalytic reaction mixture that includes a peroxide that is soluble in water or in a polar organic acid, at least one carboxylic acid, and a catalyst that is a transition metal salt selected from the group consisting of (NH4)2WO4, (NH4)6 W12O40. H2O, Na2WO4, Li2WO4, K2WO4, MgWO4, (NH4)2MoO4, (NH4)6 Mo7O24. 4H2O, MnO0 and NaVO3; the mixture is vigorously agitated for a time that is sufficient to oxidize the sulfur-containing compounds to form sulfoxides and sulfones; the reaction mixture is allowed to stand and separate into a lower aqueous layer containing the catalyst and an upper hydrocarbon layer that is recovered and from which the oxidized sulfur compounds are removed, as by solvent extraction, distillation or selective adsorption. The process can be used to reduce the sulfur content of liquid transportation fuels to 10 ppm, or less. |