Numerical simulation on particle density and reaction pathways in methane needle-plane discharge plasma at atmospheric pressure

Zhao, Yuefeng; Wang, Chao; Wang, Weizong; Li, Li; Sun, Haijie; Shao, Tao; Pan, Jie

doi:10.7498/aps.67.20172192

Cited by 6 publications

(3 citation statements)

References 29 publications

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“…When the propagation position approaches the cathode plane, almost the entire discharge region is occupied by H radicals at a nearly constant density with the order of 10 20 m -3 . The result is similar to that obtained in simulations by Zhao et al [75].…”

Section: H Radical Generation and Its Correlation With Electron Energysupporting

confidence: 92%

Temporal evolution of electron energy distribution function and its correlation with hydrogen radical generation in atmospheric-pressure methane needle–plane discharge plasmas

Liu¹,

Zhang²,

Huang³

et al. 2020

J. Phys. D: Appl. Phys.

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Non-thermal plasmas show great potential in low-temperature activation of methane (CH4) owing to the abundant energetic active species. Motivated by the fact that the chemical reactions in plasma-based CH4 conversion are dominated and regulated by the energetic electrons and various radicals, the temporal evolution of the electron energy distribution function (EEDF) and its relation to hydrogen (H) radical generation in an atmospheric-pressure CH4 needle–plane discharge plasma have been investigated numerically. The simulations are carried out using one-dimensional particle-in-cell Monte-Carlo collision and fluid dynamic models. It can be shown that during the formation and development of the streamer, a characteristic time exists, before and after which the evolution characteristic of the EEDF is reversed. This is mainly attributed to the competition between the energies continuously obtained from the electric field and the increasingly strong inelastic collisions and fast-growing low-energy electron population. When the amplitude of the applied voltage is increased, the fraction of electrons with high enough energy to participate in dissociation or ionization reactions of CH4 increases, leading to an increased H density. Besides, the characteristic time decreases exponentially, and the energy efficiency of the activation of CH4 molecules is decreased. An appropriate electron energy distribution and H radical density should be chosen to ensure acceptable product selectivity and conversion rate without excessive energy consumption; this will depend on the required products. The results presented in this work provide a partial theoretical basis for effectively optimizing the content of high-energy electrons and H radicals.

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Section: H Radical Generation and Its Correlation With Electron Energysupporting

confidence: 92%

Temporal evolution of electron energy distribution function and its correlation with hydrogen radical generation in atmospheric-pressure methane needle–plane discharge plasmas

Liu¹,

Zhang²,

Huang³

et al. 2020

J. Phys. D: Appl. Phys.

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“…The electron number density conservation equation, electron energy density conservation equation, and electron momentum conservation equation are obtained by solving the electron continuity equations [38,[54][55][56][57] ∂ n e ∂t…”

Section: Electron Transport Equationsmentioning

confidence: 99%

Fluid-chemical modeling of the near-cathode sheath formation process in a high current broken in DC air circuit breaker

Peng

Duan

et al. 2023

Chinese Phys. B

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When the contacts of medium-voltage DC air circuit breaker (DCCB) are separated, the energy distribution of arc is determined by the formation process of near electrode sheath. So, the voltage drop through the near electrode sheath is an important means to build-up the arc voltage, which determines the current-limiting performance of the DCCB directly. A numerical model describing the near electrode sheath formation process can provide insight into the physical mechanism of the arc formation and thus provide a method for arc energy regulation. In this work, a two-dimensional axisymmetric time-varying model of a medium-voltage DCCB arc when high-current interrupted was established based on a fluidchemical model involving 16 kinds of species and 47 collision reactions. The transient distributions of electron number density, positive and negative ion number density, net space charge density, axial electric field, axial potential between electrodes and near cathode sheath were obtained from the numerical model. The computational results show that the electron density in the arc column increases, then decreases, and then stabilizes during the near cathode sheath formation process, and the arc column diameter gradually becomes wider. The 11.14–12.33 V drops along the 17 µm space charge layer away from the cathode (65.5–72.5 kV/m) when the current is verying from 20–80 kA. The homogeneous external magnetic field has little effect on the distribution of particles in the near cathode sheath core, but the electron number density at the near cathode sheath periphery can increase with the magnetic field increasing and the homogeneous external magnetic field will lead to arc diffusion. The validity of the numerical model can be proved by comparison with the experiment.

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“…Converting greenhouse gases into fuels and value-added chemicals is a promising solution to implement carbon neutrality [1][2][3]. Traditional methods for greenhouse gas conversion [4][5][6] not only require conditions of high temperature and high pressure, but have various problems including coke deposition, slow start-up and poor product selectivity [7][8][9]. Plasma-catalytic CH 4 dry reforming is an emerging technology that might take advantage of plasma-catalysis interactions for improving energy conversion efficiency [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Numerical modeling and mechanism investigation of nanosecond-pulsed DBD plasma-catalytic CH₄ dry reforming

Pan

Chen

Gao

et al. 2021

J. Phys. D: Appl. Phys.

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Plasma-catalytic CH 4 dry reforming is an emerging technology that takes advantage of plasma-catalysis interactions to implement the conversion of CH 4 and CO 2 into syngas and valuable chemicals. In this work, an experiment is conducted to determine the reduced electric field E/N in the numerical modeling. In addition to essential reactor parameters, catalysis characteristics are integrated into the modeling. The 3D geometry of a nanosecond (ns) pulsed DBD plasma reactor for plasma-catalytic CH 4 dry reforming is reduced into a 0D kinetics model to investigate the inherent plasma-catalysis mechanisms. The simulation results indicate that C 2 O 4 + and CH 4 + , H and O, and CH 4 (v 13 ) are the dominant ions, radicals and vibrationally excited species, respectively. Although the reactions related to CH 4 and CO 2 consume 19.7% and 80.3% of the total electron energy, the electron energy loss caused by the CH 4 ionizations (1.3%) is distinctly higher than that caused by the CO 2 ionizations (0.4%). Surface reactions can generate a large amount of adsorbed species CH 3 (s), H(s), CO(s) and O(s). An amount of 77.2% of formaldehyde is produced by the reaction between CH 3 and O. In addition, methanol is derived from the reactions between CH 3 and OH in the pulsed dielectric barrier discharge (DBD) plasma catalytic reforming CH 4 /CO 2 . This numerical modeling reflects the practical plasma-catalysis system and therefore should be a novel tool to further understand the complicated underlying mechanism of the ns-pulsed DBD plasma-catalytic CH 4 dry reforming.

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Numerical simulation on particle density and reaction pathways in methane needle-plane discharge plasma at atmospheric pressure

Cited by 6 publications

References 29 publications

Temporal evolution of electron energy distribution function and its correlation with hydrogen radical generation in atmospheric-pressure methane needle–plane discharge plasmas

Temporal evolution of electron energy distribution function and its correlation with hydrogen radical generation in atmospheric-pressure methane needle–plane discharge plasmas

Fluid-chemical modeling of the near-cathode sheath formation process in a high current broken in DC air circuit breaker

Numerical modeling and mechanism investigation of nanosecond-pulsed DBD plasma-catalytic CH₄ dry reforming

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Numerical simulation on particle density and reaction pathways in methane needle-plane discharge plasma at atmospheric pressure

Cited by 6 publications

References 29 publications

Temporal evolution of electron energy distribution function and its correlation with hydrogen radical generation in atmospheric-pressure methane needle–plane discharge plasmas

Temporal evolution of electron energy distribution function and its correlation with hydrogen radical generation in atmospheric-pressure methane needle–plane discharge plasmas

Fluid-chemical modeling of the near-cathode sheath formation process in a high current broken in DC air circuit breaker

Numerical modeling and mechanism investigation of nanosecond-pulsed DBD plasma-catalytic CH4 dry reforming

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Numerical modeling and mechanism investigation of nanosecond-pulsed DBD plasma-catalytic CH₄ dry reforming