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Fuel Dependence of Benzene Pathways

Conference ·
The relative importance of formation pathways for benzene, an important precursor to soot formation, was determined from the simulation of 22 premixed flames for a wide range of equivalence ratios (1.0 to 3.06), fuels (C{sub 1}-C{sub 12}), and pressures (20 to 760 torr). The maximum benzene concentrations in 15 out of these flames were well reproduced within 30% of the experimental data. Fuel structural properties were found to be critical for benzene production. Cyclohexanes and C{sub 3} and C{sub 4} fuels were found to be among the most productive in benzene formation; and long-chain normal paraffins produce the least amount of benzene. Other properties, such as equivalence ratio and combustion temperatures, were also found to be important in determining the amount of benzene produced in flames. Reaction pathways for benzene formation were examined critically in four premixed flames of structurally different fuels of acetylene, n-decane, butadiene, and cyclohexane. Reactions involving precursors, such as C{sub 3} and C{sub 4} species, were examined. Combination reactions of C{sub 3} species were identified to be the major benzene formation routes with the exception of the cyclohexane flame, in which benzene is formed exclusively from cascading fuel dehydrogenation via cyclohexene and cyclohexadiene intermediates. Acetylene addition makes a minor contribution to benzene formation, except in the butadiene flame where C{sub 4}H{sub 5} radicals are produced directly from the fuel, and in the n-decane flame where C{sub 4}H{sub 5} radicals are produced from large alkyl radical decomposition and H atom abstraction from the resulting large olefins.
Research Organization:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA
Sponsoring Organization:
USDOE
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
945580
Report Number(s):
LLNL-PROC-405403
Country of Publication:
United States
Language:
English

References (43)

Combustion Reactions of Paraffin Components in Liquid Transportation Fuels Using Generic Rates journal January 2007
Investigation of the Formation of High Molecular Hydrocarbons and Soot in Premixed Hydrocarbon-Oxygen Flames journal November 1983
Kinetic study on thermal decomposition of chlorobenzene diluted in hydrogen journal March 1990
Detailed kinetic modeling of soot formation in shock-tube pyrolysis of acetylene journal January 1985
A kinetic model for the oxidation of toluene near 1200 K journal March 1992
Formation mechanisms of aromatic compounds in aliphatic flames journal April 1984
Shock tube studies of gas phase reactions preceding the soot formation process journal January 1991
Chemical Structure of Atmospheric Pressure Premixed n -Decane and Kerosene Flames journal January 1995
Experimental and computational investigation of the structure of a sooting C2H2-O2-Ar flame journal January 1989
Criteria for selection of components for surrogates of natural gas and transportation fuels journal January 2007
Unravelling combustion mechanisms through a quantitative understanding of elementary reactions journal January 2005
Formation of C 6 H 6 Isomers by Recombination of Propynyl in the System Sodium Vapour/Propynylhalide journal January 1989
Composition profiles and reaction mechanisms in a near-sooting premixed benzene/oxygen/argon flame journal January 1981
An experimental investigation of premixed fuel-rich lowpressure propene/oxygen/argon flames by laser spectroscopy and molecular-beam mass spectrometry journal January 1998
The combustion of benzene in rich premixed flames at atmospheric pressure journal May 1999
Formation of small PAHs in laminar premixed low-pressure propene and cyclopentene flames: Experiment and modeling journal January 2008
Shock-tube study of allene pyrolysis journal November 1987
Measured Flame Structure and Kinetics in a Fuel-Rich Ethylene Flame 11This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the Department of Energy, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or applied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed or represents that its use would not infringe privately owned rights. journal May 1998
Studies of a fuel-rich propane flame with photoionization mass spectrometry journal January 2005
Thermische Isomerisierungen, III. Acyclische C6H6-Isomere journal May 1971
A Journey from n -Heptane to Liquid Transportation Fuels. 1. The Role of the Allylic Radical and Its Related Species in Aromatic Precursor Chemistry journal January 2008
Olefin Chemistry in a Premixed n -Heptane Flame journal March 2007
An experimental study of fuel-rich 1,3-pentadiene and acetylene/propene flames journal June 2003
Benzene precursors and formation routes in a stoichiometric cyclohexane flame journal January 2007
Combustion Modeling and Kinetic Rate Calculations for a Stoichiometric Cyclohexane Flame. 1. Major Reaction Pathways † journal May 2007
Thermal decomposition of propyne and allene in shock waves journal August 1989
The effect of temperature on soot inception in premixed ethylene flames journal January 1996
Kinetic and thermodynamic issues in the formation of aromatic compounds in flames of aliphatic fuels journal October 1992
Combustion of gasolines in premixed laminar flames European certified and California phase 2 reformulated gasoline journal August 2001
Detailed kinetics of cyclopentadiene decomposition studied in a shock tube journal January 1997
Calculations of Rate Coefficients for the Chemically Activated Reactions of Acetylene with Vinylic and Aromatic Radicals journal November 1994
Experimental and modeling investigation of aromatic and polycyclic aromatic hydrocarbon formation in a premixed ethylene flame journal January 1996
Mechanism Reduction and Generation Using Analysis of Major Fuel Consumption Pathways for n-Heptane in Premixed and Diffusion Flames journal June 2007
Forming benzene in flames by chemically activated isomerization journal December 1989
Aromatic and Polycyclic Aromatic Hydrocarbon Formation in a Premixed Propane Flame journal October 1997
Modeling of Aromatic and Polycyclic Aromatic Hydrocarbon Formation in Premixed Methane and Ethane Flames journal August 1996
A new path to benzene in flames journal January 1991
A detailed chemical reaction mechanism for the oxidation of hydrocarbons and its application to the analysis of benzene formation in fuel-rich premixed laminar acetylene and propene flames journal January 2004
Surface Growth of Soot Particles in Premixed Ethylene/Air Flames journal April 1983
Experimental Study of 1 Atmosphere, Rich, Premixed n -heptane and iso-octane Flames journal December 1998
The Recombination of Propargyl Radicals and Other Reactions on a C 6 H 6 Potential journal October 2003
Fuel-rich flame chemistry in low-pressure cyclopentene flames journal January 2000
Tests of published mechanisms by comparison with measured laminar flame structure in fuel-rich acetylene combustion journal January 1988