Molecular beam mass spectrometry applied to determining the kinetics of reactions in flames. II. A critique of rate coefficient determinations. [Low-pressure methane--oxygen--argon flames]

Journal Article · Sun Feb 01 04:00:00 EST 1976 · Combust. Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(76)90057-2· OSTI ID:7192034

Biordi, J C; Lazzara, C P; Papp, J F

The microstructure of low-pressure methane-oxygen-argon flames was investigated using modulated molecular beam-mass spectrometry. Profiles of radical and stable species concentration, temperature, and area expansion ratio were used to calculate rate coefficients as a function of temperature for certain elementary reactions occurring in flames, namely, H + O/sub 2/ ..-->.. OH + O, H + CH/sub 4/ ..-->.. CH/sub 3/ + H/sub 2/, CO + OH ..-->.. CO/sub 2/ + H, CH/sub 3/ + O ..-->.. H/sub 2/CO + H, and H + CF/sub 3/Br ..-->.. HBr + CF/sub 3/. The profiles were modified (computationally) to simulate the effect of various perturbations and errors possible in sampling and analysis, and the effect on the rate coefficients is discussed. Detailed consideration is given to data reduction techniques, temperature profile-composition profile alignment, and the possible temperature dependence of mass spectral fragmentation. The rate coefficients are not dramatically sensitive to the imposed perturbations, although the results depend upon the nature of the reaction in question. Rate coefficients determined for high activation energy reactions and for reactions singularly responsible for the chemical behavior of a given stable species are in agreement with values determined by other techniques. Flame structure studies in which all significant radical and stable species are measured by a single technique are judged to be viable sources of high-temperature rate data for elementary reactions, where such reactions have been identified.

• Research Organization: Bureau of Mines, Pittsburgh
• OSTI ID: 7192034
• Journal Information: Combust. Flame; (United States), Journal Name: Combust. Flame; (United States) Vol. 26:1; ISSN CBFMA
• Country of Publication: United States
• Language: English

Related Subjects

090110* -- Hydrocarbon Fuels-- Properties-- (1979-1989)
10 SYNTHETIC FUELS
ALKANES
ARGON
CHEMICAL REACTION KINETICS
CRYOGENIC FLUIDS
CRYSTAL STRUCTURE
ELEMENTS
FLAMES
FLUIDS
HYDROCARBONS
KINETICS
MASS SPECTROSCOPY
METHANE
MICROSTRUCTURE
NONMETALS
ORGANIC COMPOUNDS
OXYGEN
RADICALS
RARE GASES
REACTION KINETICS
SPECTROSCOPY