Derivation of a global chemical kinetic mechanism for methane ignition and combustion

A new method for the reduction of chemical kinetic detailed mechanisms is presented. It is based on atomic fluxes calculations and reaction pathways analyses. The method was applied to a CH4/O2/Nx2 comprehensive combustion mechanism, including NOx reactions, previously validated for several types of experiments (flow reactors, shock tubes, laminar flames). A global mechanism for methane combustion and NO formation has been elaborated involving 6 chemical reactions among 10 species. This mechanism is able to reproduce accurately the ignition delays, temperature profiles and concentration profiles of major species and NO over a wide range of experimental conditions (P = 1 atm, 60% ≤ N2 ≤ 80%, 0.2 ≤ ϕ ≤ 2.2 and 900 K ≤ Tinitial ≤ 1500 K)