Energy-Efficient CO2 Conversion for Carbon Utilization Using a Gliding Arc/Glow Discharge with Magnetic Field Acceleration—Optimization and Characterization

The dry conversion of CO2 into CO and O2 provides an attractive path for CO2 utilization which allows for the use of the CO produced for the synthesis of valuable hydrocarbons. In the following work, the CO2 conversion is driven by an arc discharge at atmospheric pressure, producing hot plasma. This study presents a series of experiments aiming to optimize the process. The results obtained include the energy efficiency and the conversion rate of the process, as well as the electrical parameters of the discharge (current and voltage signals). In addition, optical emission spectroscopy diagnostics based on an analysis of C2’s Swan bands are used to determine the gas temperature in the discharge. The data is analyzed according to several aspects—an analysis of the arc’s motion based on the electrical signals; an analysis of the effect of the gas flow and the discharge current on the discharge performance for CO2 conversion; and an analysis of the vibrational and rotational temperatures of the arc channel. The results show significant improvements over previous studies. Relatively high gas conversion and energy efficiency are achieved due to the arc acceleration caused by the Lorentz force. The rotational (gas) temperatures are in the order of 5500–6000 K.