Methylcyclohexane is the simplest alkylated cyclohexane, and has been broadly used as the representative cycloalkane component in fuel surrogates. Understanding its combustion chemistry is crucial for developing kinetic models of larger cycloalkanes and practical fuels. In this work, the synchrotron vacuum ultraviolet photoionization mass spectrometry combined with molecular-beam sampling was used to investigate the species formed during the pyrolysis of methylcyclohexane and in premixed flame of methylcyclohexane. A number of pyrolysis and flame intermediates were identified and quantified, especially including radicals (e.g. CH3, C3H3, C3H5 and C5H5) and cyclic C6- and C7-intermediates (benzene, 1,3-cyclohexadiene, cyclohexene, toluene, C7H10 and C7H12, etc.). In particular, the observation of cyclic C6- and C7-intermediates provides important experimental evidence to clarify the special formation channels of toluene and benzene which were observed with high concentrations in both pyrolysis and flame of methylcyclohexane. Furthermore, the rate constants of H-abstraction of methylcyclohexane via H attack, and the isomerization and decomposition of the formed cyclic C7H13 radicals were calculated in this work. A kinetic model of methylcyclohexane combustion with 249 species and 1570 reactions was developed including a new sub-mechanism of MCH. The rate of production and sensitivity analysis were carried out to elucidate methylcyclohexane consumption, and toluene and benzene formation under various pyrolytic and flame conditions. Furthermore, the present kinetic model was also validated by experimental data from literatures on speciation in premixed flames, ignition delays and laminar flame speeds.
|Original language||English (US)|
|Number of pages||17|
|Journal||Combustion and Flame|
|State||Published - Jan 2014|
Bibliographical noteFunding Information:
Authors are grateful for the reviewers’ insightful suggestions and funding supports from National Basic Research Program of China (973 Program) (2013CB834602), Natural Science Foundation of China (50925623 and U1232127), and Chinese Academy of Sciences. We appreciate Dr. Jiuzhong Yang and Mr. Hanfeng Jin in flame experiment measurement, and Professor Katharina Kohse-Höinghaus and Dr. Yuyang Li for many helpful comments to improve this manuscript. The Super Computing Center of USTC is appreciated for Gaussian calculation.
- Kinetic modeling
- Premixed flame
- Synchrotron VUV photoionization mass spectrometry
ASJC Scopus subject areas
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Physics and Astronomy(all)