Rotating gliding arc plasma assisted hydrogen production from methane decomposition in argon

A kind of rotating gliding arc (RGA) argon plasma co-driven by tangential flow and magnetic field was investigated and used for hydrogen production from methane decomposition.In order to obtain insights into the physical characteristics of the RGA plasma, optical emission spectroscopy (OES) analysis was used to determine the electron temperature and electron density.In addition, the effects of feed flow rate and CH₄/Ar ratio on the performance of the methane decomposition process in this RGA plasma were also investigated.Results have shown that, the RGA plasma is a kind of unique plasma between thermal and non-thermal plasma, with electron temperature of 1.0-2.0 eV and electron density of 10¹⁵ cm^-3.In this system, the CH₄ conversion could be 22.1%-70.2% and it increased with the increase of flow rate or CH₄/Ar ratio.The H₂ selectivity varied from 21.2% to 61.2%, and with the augment of flow rate, the H₂ selectivity first varied slightly and then increased.A comparison of different non-thermal plasmas (e.g., microwave, radio frequency, and dielectric barrier discharge) showed that the RGA plasma could provide a relatively high CH₄ conversion and H₂ selectivity, as well as a relatively low energy consumption for H₂ production, while maintaining a high flow rate (i.e., processing capacity) of 6-20 L/min.