The inhibiting effect of CF[sub 3]Br on the reaction CH[sub 4] + O[sub 2] at 1,070 K

Conference · Thu Dec 01 04:00:00 EST 1994 · Combustion and Flame; (United States)

OSTI ID:6555754

Battin-Leclerc, F; Come, G M; Baronnet, F ^[1]

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1. Univ. de Nancy I, (France)

The continuing deterioration of the ozone layer underlines the need to find substitutes for halons (bromochlorofluorocarbons). The development of such replacements requires a good understanding of the mechanism of the inhibition of both combustion and oxidation by the compounds used so far. Therefore, this paper is focused on an experimental and theoretical study of the inhibiting effects of CF[sub 3]Br on methane oxidation in the following conditions: equimolecular CH[sub 4]-O[sub 2] mixtures, temperature 1,070 K, total pressure 1 bar, space times ranging from 1 to 7 s corresponding to methane conversions of 10%--55%. The main observed effects of the addition of this halogenated compound were a large decrease of the conversion of methane and oxygen and an important reduction of the selectivity in ethane formation. Methane oxidation and the influence of halogenated compounds on this reaction were modeled using a detailed kinetic reaction mechanism including the recent kinetic values involved in the oxidation of C[sub 1]--C[sub 2] hydrocarbons and in the reactions of brominated and fluorinated compounds. The proposed mechanism was able to reproduce the experimental data. Sensitivity analyses have facilitated a determination of the dominant steps accounting for the inhibiting effect of CF[sub 3]Br at 1,070 K. The inhibiting influence of CF[sub 3]Br on methane oxidation seems to be mainly due to a cycle, among Br, HBr, and CH[sub 3]Br, which acts as a termination step between CH[sub 3] and H radicals.

• OSTI ID: 6555754
• Report Number(s): CONF-940711--
• Conference Information: Journal Name: Combustion and Flame; (United States) Journal Volume: 99:3-4
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
034000* -- Natural Gas-- Combustion
54 ENVIRONMENTAL SCIENCES
540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ALKANES
BROMINATED ALIPHATIC HYDROCARBONS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMBUSTION
FIRE EXTINGUISHERS
FLUORINATED ALIPHATIC HYDROCARBONS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROCARBONS
INHIBITION
KINETICS
MATERIAL SUBSTITUTION
METHANE
ORGANIC BROMINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDATION
PERFORMANCE
REACTION KINETICS
THERMOCHEMICAL PROCESSES