TY - JOUR

T1 - Revisit flame chemistry of propene at elevated pressures: Insight into pressure effects on chemical structure and laminar flame propagation

AU - Mei, Bowen

AU - Zhang, Jianguo

AU - Ma, Siyuan

AU - Li, Wei

AU - Dmitriev, Artëm

AU - Шмаков, Андрей Геннадьевич

AU - Bolshova, Tatyana A.

AU - Князьков, Денис Анатольевич

AU - Li, Yuyang

N1 - Acknowledgements: The authors are grateful for the funding support from Science Center for Gas Turbine Project (P2022-B-II-017-001), National Natural Science Foundation of China (52206164) and China Postdoctoral Science Foundation (2021M702098). This work has been also financially supported by the Ministry of Science and Higher Education of the Russian Federation (project no: 075-15-2020-806). Bowen Mei appreciates the financial support from Shanghai Jiao Tong University.

PY - 2023/5/1

Y1 - 2023/5/1

N2 - This work reports an experimental and kinetic modeling investigation on flame chemistry of propene at elevated pressures. The chemical structures of premixed propene/O2/Ar flames at 2–5 atm and the equivalence ratio of 1.5 including reactants, major products and a series of intermediates were measured using the flame sampling molecular beam mass spectrometry. The maximum mole fractions of H, CH3 and C2H6 decrease with increasing pressure, while that of CH4 follows the opposite trend. Laminar burning velocities (LBVs) of propene/air mixtures at equivalence ratios of 0.7–1.5 and initial pressures up to 10 atm were measured using the spherically propagating flame method. Remarkable pressure effects can be observed, especially under the lean and rich conditions. A kinetic model for propene combustion was developed based on our recent model for ethylene combustion and recently reported chemically termolecular reactions and HCO prompt dissociation reactions. Key reactions in the propene flames were revealed using the modeling analysis, especially for those playing significant roles in the pressure effects. Two chain termination reactions including the self-combination of CH3 and the recombination between CH3 and H are found to be crucial for the observed pressure effects in maximum mole fractions of H, CH3, CH4 and C2H6. The HCO prompt dissociation can significantly promote the laminar flame propagation of propene/air mixtures due to the substantial formation of CH2O through CH2+O2 and CH3+O pathways, while the chemically termolecular reactions exhibit weak inhibition effects at equivalence ratios smaller than 1.2. The reason for the stronger pressure effects of LBVs under the lean and rich conditions is that the excess O2 and abundantly produced CH3 enhances the roles of H+O2(+M)=HO2(+M) and CH4(+M)=CH3+H(+M) in chain termination, respectively.

AB - This work reports an experimental and kinetic modeling investigation on flame chemistry of propene at elevated pressures. The chemical structures of premixed propene/O2/Ar flames at 2–5 atm and the equivalence ratio of 1.5 including reactants, major products and a series of intermediates were measured using the flame sampling molecular beam mass spectrometry. The maximum mole fractions of H, CH3 and C2H6 decrease with increasing pressure, while that of CH4 follows the opposite trend. Laminar burning velocities (LBVs) of propene/air mixtures at equivalence ratios of 0.7–1.5 and initial pressures up to 10 atm were measured using the spherically propagating flame method. Remarkable pressure effects can be observed, especially under the lean and rich conditions. A kinetic model for propene combustion was developed based on our recent model for ethylene combustion and recently reported chemically termolecular reactions and HCO prompt dissociation reactions. Key reactions in the propene flames were revealed using the modeling analysis, especially for those playing significant roles in the pressure effects. Two chain termination reactions including the self-combination of CH3 and the recombination between CH3 and H are found to be crucial for the observed pressure effects in maximum mole fractions of H, CH3, CH4 and C2H6. The HCO prompt dissociation can significantly promote the laminar flame propagation of propene/air mixtures due to the substantial formation of CH2O through CH2+O2 and CH3+O pathways, while the chemically termolecular reactions exhibit weak inhibition effects at equivalence ratios smaller than 1.2. The reason for the stronger pressure effects of LBVs under the lean and rich conditions is that the excess O2 and abundantly produced CH3 enhances the roles of H+O2(+M)=HO2(+M) and CH4(+M)=CH3+H(+M) in chain termination, respectively.

KW - Kinetic model

KW - Laminar burning velocity

KW - Laminar premixed flame

KW - Molecular beam mass spectrometry

KW - Pressure effects

KW - Propene

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85150021690&origin=inward&txGid=96540cbbe3805fd5e7d544ce95e08512

UR - https://www.mendeley.com/catalogue/cb376c26-c79c-3727-afde-9fd5a58b9fa1/

U2 - 10.1016/j.combustflame.2023.112725

DO - 10.1016/j.combustflame.2023.112725

M3 - Article

VL - 251

JO - Combustion and Flame

JF - Combustion and Flame

SN - 0010-2180

M1 - 112725

ER -