Comparisons of the structure of stoichiometric CH/sub 4/-N/sub 2/O-Ar and CH/sub 4/-O/sub 2/-Ar flames by molecular beam sampling and mass spectrometric analysis

Measurements are reported of the profiles of composition and temperature in laminar premixed flat flames of CH/sub 4/-N/sub 2 /O-Ar and CH/sub 4/-O/sub 2/-Ar. Measurements were made in near stoichiometric mixtures at 30 torr by molecular beam sampling and mass spectrometric sample analysis. All major stable species and many important unstable species were measured by this technique, many species being identified in the flame with N/sub 2/O as oxidizer for the first time. Calibration of the concentration profiles was accomplished by the use of calibration gases for stable species and by comparison of the mass spectrometer signal in the well-characterized CH /sub 4/-O/sub 2/-Ar flame with signals in the CH/sub 4/-N /sub 2/O-Ar flame and by partial equilibrium for the hydrogen-oxygen system. The measurements have identified the presence of NCO, HCN, and HNCO as reaction intermediates and the importance of these species in the reaction mechanism is discussed.Anglai