Combustion, Explosion, and Shock Waves

, Volume 48, Issue 5, pp 508–515 | Cite as

Exploring formation pathways of aromatic compounds in laboratory-based model flames of aliphatic fuels

  • N. Hansen
  • J. A. Miller
  • S. J. Klippenstein
  • P. R. Westmoreland
  • K. Kohse-Höinghaus


This presentation summarizes our recent experimental and flame modeling studies focusing on understanding of the formation of small aromatic species, which potentially grow to polycyclic aromatic hydrocarbons (PAHs) and soot. In particular, we study premixed flames, which are stabilized on a flat-flame burner under a reduced pressure of ≈15–30 torr, to unravel the important chemical pathways to aromatics formation in flames fueled by small C3–C6 hydrocarbons. Flames of allene, propyne, 1,3-butadiene, cyclopentene, and C6H12 isomers 1-hexene, cyclohexane, 3,3-dimethyl-1-butene, and methylcyclopentane are analyzed by flame-sampling molecular-beam time-of-flight mass spectrometry. Isomer-specific experimental data and detailed modeling results reveal the dominant fuel-destruction pathways and the influence of different fuel structures on the formation of aromatic compounds and their commonly considered precursors. As a specific aspect, the role of resonance-stabilized free radical reactions is addressed for this large number of similar flames of structurally different fuels. While propargyl and allyl radicals dominate aromatics formation in most flames, contributions from reactions involving other resonance-stabilized radicals like i-C4H5 and C5H5 are revealed in flames of 1,3-butadiene, 3,3-dimethyl-1-butene, and methylcyclopentane. Dehydrogenation processes of the fuel are found to be important benzene formation steps in the cyclohexane flame and are likely to also contribute in methylcyclopentane flames.


formation of polycyclic aromatic hydrocarbons and soot resonance-stabilized free radicals hydrocarbon flames identification of species in flames molecular-beam mass spectrometry photoionization by vacuum ultraviolet 


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  1. 1.
    H. Bockhorn, A. D’Anna, A. F. Sarofim, et al., Combustion Generated Fine Carbonaceous Particles (Karlsruher Inst. für Technologie, Karlsruhe, 2009).Google Scholar
  2. 2.
    H. Wang, “Formation of Nascent Soot and Other Condensed-Phase Materials in Flames,” Proc. Combust. Inst. 33(1), 41–67 (2011).CrossRefGoogle Scholar
  3. 3.
    J. M. Samet, S. L. Zeger, F. Dominici, et al., Research Report N 94. Part I: National Morbidity, Mortality, and Air Pollution Study. Part II: Morbidity and Mortality from Air Pollution in the United States (Health Effects Inst., Boston, 2000).Google Scholar
  4. 4.
    S. Solomon, D. Qin, M. Manning, et al. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge Univ. Press, Cambridge, Unitered Kingdom and New York, 2007).Google Scholar
  5. 5.
    J. A. Miller, M. J. Pilling, and J. Troe, “Unravelling Combustion Mechanisms through a Quantitative Understanding of Elementary Reactions,” Proc. Combust. Inst. 30(1), 43–88 (2005).CrossRefGoogle Scholar
  6. 6.
    N. Hansen, T. A. Cool, P. R. Westmoreland, and K. Kohse-Höinghaus, “Recent Contributions of Flame-Sampling Molecular-Beam Mass Spectrometry to a Fundamental Understanding of Combustion Chemistry,” Progr. Energy Combust. Sci. 35(2), 168–191 (2009).CrossRefGoogle Scholar
  7. 7.
    C. S. McEnally, L. D. Pfefferle, B. Atakan, and K. Kohse-Höinghaus, “Studies of Aromatic Hydrocarbon Formation Mechanisms in Flames: Progress towards Closing the Fuel Gap.” Progr. Energy Combust. Sci. 32(3), 247–294 (2006).CrossRefGoogle Scholar
  8. 8.
    H. Richter and J. B. Howard, “Formation of Polycyclic Aromatic Hydrocarbons and their Growth to Soot-a Review of Chemical Reaction Pathways,” Progr. Energy Combust. Sci. 26(4–6), 565–608 (2000).CrossRefGoogle Scholar
  9. 9.
    P. R. Westmoreland, M. E. Law, T. A. Cool, et al., “Analysis of Flame Structure by Molecular-Beam Mass Spectrometry using Electron-Impact and Synchrotron-Photon Ionization,” Fiz. Goreniya Vsryva 42(6), 58–63 (2006) [Combust., Expl., Shock Waves 42 (6), 672–677 (2006)].Google Scholar
  10. 10.
    T. A. Cool, A. McIlroy, F. Qi, et al., “Photoionization Mass Spectrometer for Studies of Flame Chemistry with a Synchrotron Light Source,” Rev. Sci. Instr. 76(9), 094102 (2005).ADSCrossRefGoogle Scholar
  11. 11.
    C. A. Taatjes, N. Hansen, D. L. Osborn, et al. “’Imaging’ Combustion chemistry via Multiplexed Synchrotron-Photoionization Mass Spectrometry,” Phys. Chem. Chem. Phys. 10(1), 20–34 (2008).CrossRefGoogle Scholar
  12. 12.
    T. A. Cool, J. Wang, K. Nakajima, et al., “Photoionization Cross Sections for Reaction Intermediates in Hydrocarbon Combustion,” Int. J. Mass Spectrom. 247(1–3), 18–27 (2005).ADSGoogle Scholar
  13. 13.
    J. Wang, B. Yang, T. A. Cool, et al., “Near-Threshold Absolute Photoionization Cross-Cections of Some Reaction Intermediates in Combustion,” Int. J. Mass Spectrom. 269(3), 210–220 (2008).ADSCrossRefGoogle Scholar
  14. 14.
    D. K. Hahn, S. J. Klippenstein, and J. A. Miller, “A Theoretical Analysis of the Reaction between Propargyl and Molecular Oxygen,” Faraday Discuss. Roy. Soc. Chem. 119, 79–100 (2001).ADSCrossRefGoogle Scholar
  15. 15.
    S. S. Vasu, J. Zádor, D. F. Davidson, et al., “High-Temperature Measurements and a Theoretical Study of the Reaction of OH with 1,3-butadiene,” J. Phys. Chem. A. 114(32), 8312–8318 (2010).CrossRefGoogle Scholar
  16. 16.
    J. A. Miller and C. F. Melius, “Kinetic and Thermodynamic Issues in the Formation of Aromatic-Compounds in Flames of Aliphatic Fuels,” Combust. Flame 91(1), 21–39 (1992).CrossRefGoogle Scholar
  17. 17.
    J. P. Senosiain and J. A. Miller, “The Reaction of n- and i-C4H5 Radicals with Acetylene,” J. Phys. Chem. A 111(19), 3740–3747 (2007).CrossRefGoogle Scholar
  18. 18.
    S. J. Klippenstein and J. A. Miller, “From the Time-Dependent, Multiple-Well Master Equation to Phenomenological Rate Coefficients,” J. Phys. Chem. A 106(40), 9267–9277 (2002).CrossRefGoogle Scholar
  19. 19.
    J. A. Miller and S. J. Klippenstein, “From the Multiple-Well Master Equation to Phenomenological Rate Coefficients: Reactions on a C3H4 Potential Energy Surface,” J. Phys. Chem. A 107(15), 2680–2692 (2003).CrossRefGoogle Scholar
  20. 20.
    A. Fernandez-Ramos, J. A. Miller, S. J. Klippenstein, and D. G. Truhlar, “Modeling the Kinetics of Bimolecular Reactions,” Chem. Rev. 106(11), 4518–4584 (2006).CrossRefGoogle Scholar
  21. 21.
    J. A. Miller and S. J. Klippenstein, “Master Equation Methods in Gas Phase Chemical Kinetics,” J. Phys. Chem. A 110(36), 10528–10544 (2006).CrossRefGoogle Scholar
  22. 22.
    Y. Georgievskii, S. J. Klippenstein, and J. A. Miller, “Association Rate Constants for Reactions between Resonance-Stabilized Radicals: C3H3 + C3H3, C3H3 + C3H5, and C3 H5 + C3H5,” Phys. Chem. Chem. Phys. 9(31), 4259–4268 (2007).CrossRefGoogle Scholar
  23. 23.
    N. Hansen, J. A. Miller, C. A. Taatjes, et al., “Photoionization Mass Spectrometric Studies and Modeling of Fuel-Rich Allene and Propyne Flames,” Proc. Combust. Inst. 31(1), 1157–1164 (2007).CrossRefGoogle Scholar
  24. 24.
    N. Hansen, J. A. Miller, P. R. Westmoreland, et al., “Isomer-Specific Combustion Chemistry in Allene and Propyne Flames,” Combust. Flame 156(11), 2153–2164 (2009).CrossRefGoogle Scholar
  25. 25.
    N. Hansen, J. A. Miller, T. Kasper, et al., “Benzene Formation in Premixed Fuel-Rich 1,3-Butadiene Flames,” Proc. Combust. Inst. 32(1), 623–630 (2009).CrossRefGoogle Scholar
  26. 26.
    N. Hansen, T. Kasper, S. J. Klippenstein, et al., “Initial Steps of Aromatic Ring Formation in a Laminar Premixed Fuel-Rich Cyclopentene Flame,” J. Phys. Chem. A 111(19), 4081–4092 (2007).CrossRefGoogle Scholar
  27. 27.
    N. Hansen, T. Kasper, B. Yang, et al., Fuel-Structure Dependence of Benzene Formation Processes in Premixed Flames Fueled by C6H12 Isomers,” Proc. Combust. Inst. 33(1), 585–592 (2011).CrossRefGoogle Scholar
  28. 28.
    N. Hansen, W. Li, M. E. Law, et al., “The Importance of Fuel Dissociation and Propargyl Plus Allyl Association for the Formation of Benzene in a Fuel-Rich 1-Hexene Flame,” Phys. Chem. Chem. Phys. 12(38), 12112–12122 (2010).CrossRefGoogle Scholar
  29. 29.
    M. E. Law, P. R. Westmoreland, T. A. Cool, et al., “Benzene Precursors and Formation Routes in a Stoichiometric Cyclohexane Flame,” Proc. Combust. Inst. 31(1), 565–573 (2007).CrossRefGoogle Scholar
  30. 30.
    W. Li, M. E. Law, P. R. Westmoreland, et al., “Multiple Benzene-Formation Paths in a Fuel-Rich Cyclohexane Flame,” Combust. Flame 158(11), 2077–2089 (2011).CrossRefGoogle Scholar
  31. 31.
    A. Lamprecht, B. Atakan, and K. Kohse-Höinghaus, “Fuel-Rich Propene and Acetylene Flames: A Comparison of their Flame Chemistries,” Combust. Flame 122(4), 483–491 (2000).CrossRefGoogle Scholar
  32. 32.
    B. Atakan, A. T. Hartlieb, J. Brand, and K. Kohse- Höinghaus, “An Experimental Investigation of Premixed Fuel-Rich Low-Pressure Propene/Oxygen/Argon Flames by Laser Spectroscopy and Molecular-Beam Mass Spectrometry,” Proc. Combust. Inst. 27(1), 435–444 (1998).Google Scholar
  33. 33.
    A. Lamprecht, B. Atakan, and K. Kohse-Höinghaus, “Fuel-Rich Flame Chemistry in Low-Pressure Cyclopentene Flames,” Proc. Combust. Inst. 28(2), 1817–1824 (2000).CrossRefGoogle Scholar
  34. 34.
    G. González Alatorre, H. Böhm, B. Atakan, and K. Kohse-Höinghaus, “Experimental and Modelling Study of 1-Pentene Combustion at Fuel-Rich Conditions,” Z. Phys. Chem. 215(8), 981–995 (2001).CrossRefGoogle Scholar
  35. 35.
    B. Atakan, A. Lamprecht, and K. Kohse-Höinghaus, “An Experimental Study of Fuel-Rich 1,3-Pentadiene and Acetylene/Propene Flames,” Combust. Flame 133(4), 431–440 (2003).CrossRefGoogle Scholar
  36. 36.
    P. R. Westmoreland, A. M. Dean, J. B. Howard, and J. P. Longwell, “Forming Benzene in Flames by Chemically Activated Isomerization,” J. Phys. Chem. 93(25), 8171–8180 (1989).CrossRefGoogle Scholar
  37. 37.
    P. R. Westmoreland, J. B. Howard, and J. P. Longwell, “Tests of Published Mechanisms by Comparison with Measured Laminar Flame Structure in Fuel-Rich Acetylene Combustion,” Proc. Combust. Inst. 21(1), 773–782 (1986).Google Scholar
  38. 38.
    T. Carriére, P. R. Westmoreland, A. Kazakov, et al., “Modeling Ethylene Combustion from Low to High Pressure,” Proc. Combust. Inst. 29(1), 1257–1266 (2002).CrossRefGoogle Scholar
  39. 39.
    M. E. Law, T. Carriére, and P. R. Westmoreland, “Allene Addition to a Fuel-Lean Ethylene Flat Flame,” Proc. Combust. Inst. 30(1), 1353–1361 (2005).CrossRefGoogle Scholar
  40. 40.
    N. M. Marinov, M. J. Castaldi, C. F. Melius, and W. Tsang, “Aromatic and Polycyclic Aromatic Hydrocarbon Formation in a Premixed Propane Flame,” Combust. Sci. Technol. 128(1–6), 295–342 (1997).CrossRefGoogle Scholar
  41. 41.
    J. A. Miller, S. J. Klippenstein, Y. Georgievskii, et al., “Reactions between Resonance-Stabilized Radicals: Propargyl Plus Allyl,” J. Phys. Chem. A. 114(14), 4881–4890 (2010).CrossRefGoogle Scholar
  42. 42.
    C. J. Pope and J. A. Miller, “Exploring Old and New Benzene Formation Pathways in Low-Pressure Premixed Flames of Aliphatic Fuels,” Proc. Combust. Inst. 28 (2), 1519–1527 (2000).Google Scholar
  43. 43.
    N. Hansen, S. J. Klippenstein, C. A. Taatjes, et al., “Identification and Chemistry of C4H3 and C4H5 Isomers in Fuel-Rich Flames,” J. Phys. Chem. A 110(10), 3670–3678 (2006).CrossRefGoogle Scholar
  44. 44.
    J. A. Miller, “Theory and Modeling in Combustion Chemistry,” Proc. Combust. Inst. 26(1), 461–480 (1996).Google Scholar
  45. 45.
    L. B. Harding, S. J. Klippenstein, and Y. Georgievskii, “On the Combination Reactions of Hydrogen Atoms with Resonance-Stabilized Hydrocarbon Radicals,” J. Phys. Chem. A 111(19), 3789–3801 (2007).CrossRefGoogle Scholar
  46. 46.
    L. V. Moskaleva, A. M. Mebel, and M. C. Lin, “The CH3 + C5H5 Reaction: A Potential Source of Benzene at High Temperatures,” Proc. Combust. Inst. 26(1), 521–526 (1996).Google Scholar

Copyright information

© Pleiades Publishing, Ltd. 2012

Authors and Affiliations

  • N. Hansen
    • 1
  • J. A. Miller
    • 2
  • S. J. Klippenstein
    • 2
  • P. R. Westmoreland
    • 3
  • K. Kohse-Höinghaus
    • 4
  1. 1.Combustion Research FacilitySandia National LaboratoriesLivermoreUSA
  2. 2.Chemical Sciences and Engineering DivisionArgonne National LaboratoryArgonneUSA
  3. 3.Department of Chemical and Biomolecular EngineeringNorth Carolina State UniversityRaleighUSA
  4. 4.Department of ChemistryBielefeld UniversityBielefeldGermany

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