Forming benzene in flames by chemically activated isomerization

Journal Article · Thu Dec 14 04:00:00 EST 1989 · Journal of Physical Chemistry; (USA)

OSTI ID:6706916

Howard, J B; Longwell, J P ^[1]; Dean, A M ^[2]; Westmoreland, P R ^[3]

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1. Massachusetts Institute of Technology, Cambridge (USA)
2. Exxon Research and Engineering Co., Annandale, NJ (USA)
3. Massachusetts Institute of Technology, Cambridge (USA) Exxon Research and Engineering Co., Annandale, NJ (USA)

Benzene is not formed in flames by high-pressure-limit addition reactions, as had been implied previously, but by chemically activated addition and isomerization reactions. First, mole-fraction and rate data for molecules and free radicals were measured in a lightly sooting, laminar, premixed flame of C{sub 2}H{sub 2}/O{sub 2}/Ar at 1000-1700 K and 2.67 kPa (20 Torr) by using molecular-beam mass spectrometry. Second, mechanisms were screened in this flame and a similar 1,3-butadiene flame by using high-pressure-limit rate constants. Third, pressure-dependent rate constants for all channels of successful mechanisms were analyzed by bimolecular quantum-RRK calculations. Finally, data tests with these more accurate rate constants showed that only additions of vinylic 1-C{sub 4}H{sub 5} and 1-C{sub 4}H{sub 3} radicals to C{sub 2}H{sub 2} were fast enough to account for the highest observed rates of benzene formation, forming benzene and phenyl directly by chemically activated channels. These reactants have been suggested before, but the pathways are crucially different from high-pressure-limit routes.

• OSTI ID: 6706916
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 93:25; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
AROMATICS
BENZENE
CALCULATION METHODS
CHEMICAL ACTIVATION
DATA
DATA ANALYSIS
EXPERIMENTAL DATA
FLAMES
HYDROCARBONS
INFORMATION
MEASURING INSTRUMENTS
MEASURING METHODS
NUMERICAL DATA
ORGANIC COMPOUNDS
VERY HIGH TEMPERATURE