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

The present study investigated the use of pseudo-detailed chemical kinetic mechanisms to simulate the liquid-phase oxidation representative of severely-hydrotreated jet fuels over a wide range of temperatures and initial dissolved O-2 concentrations. Earlier kinetic mechanisms provide reasonable simulations of oxidation over a range of temperatures, but not over a wide range of initial dissolved O-2 concentrations. Alkyl-peroxy radical isomerization was shown to be unimportant in kinetic modeling of oxygen profiles in Exxsol D-80 oxidation. The addition of peroxy radical decomposition to the pseudo-detailed mechanism enables reasonable simulations of oxidation over a range of temperatures and dissolved O-2 concentrations. Analysis of reaction rate parameters used in the pseudo-detailed mechanism to simulate oxidation suggests that benzylic aromatic hydrocarbons, even at low concentrations, play a significant role in the oxidation of jet fuels. Further analysis, both modeling and experiment, of the relationship between paraffin content, aromatic content, and antioxidant additive concentrations in thermal-oxidative degradation and deposition processes is warranted.