关键词: 大气压放电等离子体/
甲烷放电等离子体/
针-板放电/
流体模型
English Abstract
Numerical simulation on particle density and reaction pathways in methane needle-plane discharge plasma at atmospheric pressure
Zhao Yue-Feng1,Wang Chao1,2,
Wang Wei-Zong3,
Li Li4,
Sun Hao2,
Shao Tao2,
Pan Jie1
1.School of Physics and Electronics, Shandong Normal University, Jinan 250014, China;
2.Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China;
3.Department of Chemistry, University of Antwerp, Wilrijk 2610, Belgium;
4.State Grid Jinan Power Supply Company, Jinan 250012, China
Fund Project:Project supported by the National Natural Science Foundation of China (Grant Nos. 51637010, 51707111) and the Natural Science Foundation of Shandong Province, China (Grant No. ZR2015AQ008).Received Date:10 October 2017
Accepted Date:11 February 2018
Published Online:20 April 2019
Abstract:Methane needle-plane discharge has practical application prospect and scientific research significance since methane conversion heavy oil hydrogenation is formed by coupling methane needle-plane discharge with heavy oil hydrogenation, which can achieve high-efficient heavy oil hydrogenation and increase the yields of high value-added light olefins. In this paper, a two-dimensional fluid model is built up for numerically simulating the methane needle-plane discharge plasma at atmospheric pressure. Spatial and axial distributions of electric intensity, electron temperature and particle densities are obtained. Reaction yields are summarized and crucial pathways to produce various kinds of charged and neutral particles are found out. Simulation results indicate that axial evolutions of CH3+ and CH4+ densities, electric intensity and electron temperature are similar and closely related. The CH5+ and C2H5+ densities first increase and then decrease along the axial direction. The CH3 and H densities have nearly identical spatial and axial distributions. Particle density distributions of CH2, C2H4 and C2H5 are obviously different in the area near the cathode but comparatively resemblant in the positive column region. The CH3+ and CH4+ are produced by electron impact ionizations between electrons and CH4. The CH5+ and C2H5+ are respectively generated by molecular impact dissociations between CH3+ and CH4 and between CH4+ and CH4. Electron impact decomposition between electrons and CH4 is a dominated reaction to produce CH3, CH2, CH and H. The reactions between CH2 and CH4 and between electrons and C2H4 are critical pathways to produce C2H4 and C2H2, respectively. In addition, the yields of electron impact decomposition reactions between electrons and CH4 and reactions between CH2 and CH4 account for 52.15% and 47.85% of total yields of H2 respectively.
Keywords: discharge plasma at atmospheric pressure/
methane discharge plasma/
needle-plane discharge/
fluid model
