Global modeling on partial oxidation of methane to oxygenates and syngas in non-equilibrium plasma

Abstract

In this paper, plasma kinetics of CH4/O2 at atmospheric pressure are of interest for applications in plasma chemistry where partial oxidation of methane to oxygenates and syngas are investigated by zero-dimensional global model. Effect of methane mole fraction ranging from 5% to 99% on plasma kinetics is studied in detail. It is found that electron density and electron temperature change periodically with periodic variation of power density pulse. The number densities of free radicals, ions and stable molecules are discussed as a function of simulation time and CH4/O2 molar ratio. Conversions of inlet gases, selectivities and yields of important products, and optimum methane content for methanol and formaldehyde formation are calculated and presented. In addition, CH3 radical is found to be the key intermediate for oxygenates production by analyzing the underlying dominant reaction pathways. Finally, a schematic overview of the transformation relationship between dominant plasma species is also summarized and shown.