Kinetic Effects of n-Heptane Addition on Low and High Temperature Oxidation of Methane in a Jet-Stirred Reactor

The kinetic effects of n-heptane addition on low and high temperature oxidations of methane were experimentally investigated over a range of temperatures from 800 to 1200 K, at the equivalence ratio of 0.5 in an atmospheric jet-stirred reactor (JSR). The n-heptane content in the methane/n-heptane mixture was varied between 0 and 100%. The mole fractions of CH4, nC7H16, O2, CO, CO2, CH2O, and C2H4 were determined respectively in the present experiments, and the NUI mechanism was employed to perform the numerical studies under the same conditions by using the perfectly stirred reactor model. The results show that the onset temperature of the oxidation of methane decreases with the increase of the n-heptane content in methane/n-heptane mixture significantly, and that even a small amount of n-heptane can cause an obvious shift of high temperature oxidation of methane to lower temperature. According to the reaction path analysis, the initial kinetic enhancement reactions of n-heptane in the oxidation of methan...