Dry reforming of CO2CH4 assisted by high-frequency AC gliding arc discharge: Electrical characteristics and the effects of different parameters

•A gliding arc plasma reactor driven by high frequency AC power is proposed.•Breakdowns occurred hundreds of times within a gliding period in HFAC GAD.•The electrode thickness showed a strong effect on the discharge stability.•The highest conversion rate of the reactants was achieved at 1.65 mmol/L.

In this work, a knife-shaped gliding arc discharge (GAD) reactor driven by high frequency AC (HFAC) power was employed to convert CO2 and CH4. The HFAC GAD exhibited good performance in dry reformation of CO2CH4. The development process with the HFAC GAD at a low gas flow rate was recorded and it is discussed with U-I waveforms and discharge images. The effects of input voltage, total gas flow rate, minimum electrode gap distance, and electrode thickness were investigated in terms of the CO2CH4 conversion rate, selectivity of CO, H2, and C2 hydrocarbons, specific energy density, and energy efficiency. The energy efficiency ranged from 1.58 to 2.21 mmol/kJ under changing operating conditions. The best conversions of CO2 and CH4 were achieved as 52.32% and 58.85%, respectively, with an energy efficiency of 1.65 mmol/kJ.