Modeling the liquid-phase oxidation of hydrocarbons over a range of temperatures and dissolved oxygen concentrations with pseudo-detailed chemical kinetics

The ability of pseudo-detailed chemical kinetic modeling to simulate the oxidation behavior of Exxsol D-80, a paraffin blend whose oxidative characteristics are representative of severely hydrotreated jet fuels, is assessed. The effects of temperature and initial dissolved O2 concentration on oxidation are considered. A 17-step pseudo-detailed mechanism is shown to provide reasonable simulations of Exxsol D-80 oxidation over a range of temperatures, but not over a range of initial dissolved O2 concentrations. The addition of alkyl-peroxy radical isomerization to the pseudo-detailed mechanism did not reconcile the initial dissolved O2 limitation. With the addition of a peroxy radical decomposition reaction to the original 17-step pseudo-detailed mechanism, reasonable simulations of Exxsol D-80 oxidation over a range of temperatures and initial dissolved O2 concentrations were obtained. Analysis of the rate parameters associated with peroxy radical decomposition suggests that aromatic hydrocarbons play a significant role in the oxidation of fuels, even at low (<1% by weight) aromatic levels.