Reaction pathways of producing and losing particles in atmospheric pressure methane nanosecond pulsed needle-plane discharge plasma

Yuefeng Zhao,Chao Wang,Li Li,Lijuan Wang,Jie Pan

doi:10.1063/1.5018667

Abstract

In this work, a two-dimensional fluid model is built up to numerically investigate the reaction pathways of producing and losing particles in atmospheric pressure methane nanosecond pulsed needle-plane discharge plasma. The calculation results indicate that the electron collisions with CH4 are the key pathways to produce the neutral particles CH2 and CH as well as the charged particles e and CH3+. CH3, H2, H, C2H2, and C2H4 primarily result from the reactions between the neutral particles and CH4. The charge transfer reactions are the significant pathways to produce CH4+, C2H2+, and C2H4+. As to the neutral species CH and H and the charged species CH3+, the reactions between themselves and CH4 contribute to substantial losses of these particles. The ways responsible for losing CH3, H2, C2H2, and C2H4 are CH3 + H → CH4, H2 + CH → CH2 + H, CH4+ + C2H2 → C2H2+ + CH4, and CH4+ + C2H4 → C2H4+ + CH4, respectively. Both electrons and C2H4+ are consumed by the dissociative electron-ion recombination reactions. The essential reaction pathways of losing CH4+ and C2H2+ are the charge transfer reactions.

Highlights

As the main ingredient of natural gas, marsh gas, and mine gas, methane (CH4) is the raw material to generate hydrogen, carbon black, carbon monoxide, formaldehyde, and acetylene and the essential fuel for civil and industrial heating
The calculation results indicate that the electron collisions with CH4 are the key pathways to produce the neutral particles CH2 and CH as well as the charged particles e and CH3þ
CH3, H2, H, C2H2, and C2H4 primarily result from the reactions between the neutral particles and CH4

Summary

Introduction

As the main ingredient of natural gas, marsh gas, and mine gas, methane (CH4) is the raw material to generate hydrogen, carbon black, carbon monoxide, formaldehyde, and acetylene and the essential fuel for civil and industrial heating. CH4 has widely received attention and applications in fields such as crop fertilization, gas power generation, synthesis gas production, and nanomaterial synthesis.. As a result of employing catalyst and near hydrogen environment under the conditions of high gas pressure and high temperature, the traditional heavy oil hydrogenation technique has a few shortcomings, i.e., high energy consumption, low light oil yield, and the catalyst being easy to coke. Previous research has indicated that the nanosecond pulsed discharge can produce high chemical activity and non-equilibrium discharge plasma under a wide range of the gas pressures.. By combining the methane nanosecond pulsed discharge with the traditional heavy oil hydrogenation, the methane plasma conversion heavy oil hydrogenation technique may realize the high efficiency heavy oil hydrogenation and increase the production of the high valueadded low carbon olefins, which have extensive application prospects and important research significance Previous research has indicated that the nanosecond pulsed discharge can produce high chemical activity and non-equilibrium discharge plasma under a wide range of the gas pressures. By combining the methane nanosecond pulsed discharge with the traditional heavy oil hydrogenation, the methane plasma conversion heavy oil hydrogenation technique may realize the high efficiency heavy oil hydrogenation and increase the production of the high valueadded low carbon olefins, which have extensive application prospects and important research significance

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Conclusion