Extractive and Catalytic Oxidative Desulfurization of Gasoline by Methyltrioxorhenium in Ionic Liquids

For the first time, methyltrioxorhenium (MTO) is used as a catalyst for the extractive and catalytic oxidative desulfurization (ECODS) of model oil and fluid catalytic cracking (FCC) gasoline, with 30% H 2 O 2 as the oxidant and ionic liquids as the solvent and extractant for the removal of organic sulfur at moderate temperatures (below 60 °C). The ECODS is highly efficient with low catalyst loading (1–5 mol %). The mono- and bisperoxorhenium compounds formed via the reactions of MTO and H 2 O 2 are proven to be catalytic active species for the oxidation of organic sulfides, such as thioethers, thiophene, and alkyl thiophenes contained in the FCC gasoline. After the oxidation, the oxidized products were easily extracted into the ionic liquid phase from the oil phase. The sulfur removal can reach up to 99% for the model oil (with an initial sulfur content of 200 μg/mL) and 91% of the Fushun FCC gasoline (with an initial sulfur content of ca. 142 μg/mL) within 2 h under the optimized conditions. The octane number of the gasoline is reduced by only about 0.7, without significant changes in hydrocarbon group composition after desulfurization.