Investigation on fuel-rich premixed flames of monocyclic aromatic hydrocarbons: Part I. Intermediate identification and mass spectrometric analysis

Journal Article · Fri Jan 15 04:00:00 EST 2010 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2009.07.021· OSTI ID:21248854

Li, Yuyang ^[1]; Zhang, Lidong; Yuan, Tao; Zhang, Kuiwen; Yang, Jiuzhong; Yang, Bin; Qi, Fei ^[1]; Law, Chung K ^[2]

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1. National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China)
2. Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States)

Fuel-rich premixed flames of seven monocyclic aromatic hydrocarbons (MAHs) including benzene, toluene, styrene, ethylbenzene, ortho-xylene, meta-xylene, and para-xylene were studied at the pressure of 30 Torr and comparable flame conditions (C/O = 0.68). The measurement of photoionization efficiency (PIE) spectra facilitated the comprehensive identification of combustion intermediates from m/z = 15 to 240, while mass spectrometric analysis was performed to gain insight into the flame chemistry. Features of the sidechain structure in fuel molecule affect the primary decomposition and aromatics growth processes, resulting in different isomeric structures or compositions of some primary products. This effect becomes weaker and weaker as both processes proceed. The results indicate that most intermediates are identical in all flames, leading to similar intermediate pools of these fuels. Consequently the chemical structures of flames fueled by different MAHs are almost identical, subsequent to the initial fuel-specific decomposition and oxidation that produce the primary intermediates. On the other hand, special features of the sidechain structure can affect the concentration levels of PAHs by increasing the concentrations of the key intermediates including the benzyl radical and phenylacetylene. Therefore, the total ion intensities of the PAH intermediates in the flames were observed to increase in the order of: benzene < toluene and styrene < four C{sub 8}H{sub 10}, which implies the same order of the sooting tendency. (author)

• OSTI ID: 21248854
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 1 Vol. 157; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
AROMATICS
BENZENE
BENZYL RADICALS
CHEMICAL REACTIONS
COMBUSTION
DECOMPOSITION
EFFICIENCY
FAR ULTRAVIOLET RADIATION
FLAMES
Flame chemistry
HYDROCARBONS
IONS
Monocyclic aromatic fuels
PAH formation
PHOTOIONIZATION
POLYCYCLIC AROMATIC HYDROCARBONS
PRESSURE RANGE KILO PA
REACTION INTERMEDIATES
SPECTRA
STYRENE
TOLAN
TOLUENE
XYLENES