Oxidative Desulfurization of Jet Fuels and Its Impact on Thermal-Oxidative Stability

Abstract

The effect of oxidative desulfurization (ODS) on the thermal oxidative stability of Chinese RP-3 jet fuel was systematically investigated using phosphotungstic acid (PTA)/hydrogen peroxide/acetic acid (HAc) as the oxidative reaction system, and acetonitrile solution and silica gel as extractant and sorbent to remove the oxidized organosulfur compounds. The oxidative reactions of organosulfur compounds were experimentally studied to obtain an optimal reaction parameter, under which about 95% organosulfur was removed with oxidative desulfurization-extraction (ODS-E) and oxidative desulfurization-adsorption (ODS-A). Solid deposit from thermal stressing of Chinese RP-3 jet fuels with or without ODS was selected to characterize the thermal oxidative stability that increases in the following order: RP-3 (ODS-E) < original RP-3 < RP-3 (ODS-A). A solid phase extraction-gas chromatrography-mass spectrometer (SPE-GC-MS) method was used to separate, identify, and determine the concentrations of polar species in the jet fuels after different ODS treatments. It was found that the concentration of substituted phenols in the jet fuel after ODS-E treatment increases by 100%, and total polar species, by 80−250%. Meanwhile after ODS-A treatment, both the polar species formed in ODS and 90% substituted phenols and 60% total polar species in the original jet fuel are effectively removed.