Rotating gliding arc assisted methane decomposition in nitrogen for hydrogen production

Abstract

Hydrogen production from methane decomposition via an atmospheric pressure rotating gliding arc (RGA) discharge reactor co-driven by a magnetic field and tangential flow is investigated. The motion and V–I characteristics of the RGA are studied with a high-speed camera and oscilloscope. Optical emission spectroscopy (OES) is used to characterize RGA plasmas in N2 and CH4 + N2, and the RGA plasma is shown to occur as a warm plasma. For the CH4 + N2 plasma, CN, C2, and CH spectral lines are observed. The vibrational and rotational temperatures are 0.56–0.86 eV and 1325–1986 K, respectively. The effects of load resistance, the CH4/N2 ratio, and the feed flow rate on the performance of methane decomposition are investigated. The maximum CH4 conversion rate and H2 selectivity are 91.8% and 80.7% when the CH4/N2 ratio is 0.1 and 0.05, respectively, at a flow rate of 6 L/min. The possible reaction mechanisms of the methane decomposition process are discussed. This study is expected to establish a basis for the further industrial applications of H2 production.