Inhibition of hydrocarbon oxidation in laminar flames and detonations by halogenated compounds. [CF/sub 3/Br]

Conference · Fri Jan 08 04:00:00 EST 1982

OSTI ID:5191638

Westbrook, C K

A detailed chemical kinetic reaction mechanism is developed to describe the inhibition of hydrocarbon fuel oxidation by halogenated species. Included in this mechanism are the halogen acids HCl, HBr, and HI, as well as halogenated hydrocarbons formed by combining together Cl, Br, or I atoms with methyl, ethyl, or vinyl radicals. Also included is a submechanism describing the kinetics of the combustion of CF/sub 3/Br. The resulting mechanism is combined with a complete hydrocarbon oxidation mechanism and used to study inhibition of laminar flames and detonations in hydrocarbon-air mixtures. In all of the cases examined, the halogenated species act by catalyzing the recombination of H atoms into relatively non-reactive H/sub 2/ molecules, reducing the available radical pool and lowering the overall rate of chain branching. In agreement with experimental observations, the present modeling study indicates that I atoms are the most effective, Br atoms are slightly less effective than I atoms, and Cl atoms are very much less effective as kinetic inhibitors. The additional fuel content of the halogenated hydrocarbons makes their inhibition efficiency vary with equivalence ratio, and for all of the inhibitors increased pressure also increases the inhibition efficiency. Discussions of the kinetic factors responsible for this behavior are presented.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5191638
• Report Number(s): UCRL-87077; CONF-820801-5; ON: DE82007573
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
BROMINATED ALIPHATIC HYDROCARBONS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
COMBUSTION KINETICS
DATA
DETONATIONS
EXPERIMENTAL DATA
FLAMES
FLUORINATED ALIPHATIC HYDROCARBONS
FUELS
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDRIODIC ACID
HYDROBROMIC ACID
HYDROCARBONS
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
INFORMATION
INHIBITION
INORGANIC ACIDS
IODINATED ALIPHATIC HYDROCARBONS
IODINE COMPOUNDS
KINETICS
NUMERICAL DATA
ORGANIC BROMINE COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
OXIDATION
REACTION KINETICS