A SDBD Reactor for the Removal of Oxygen Traces in Hydrogen Operated above Atmospheric Pressure: Experiment and Simulation

Abstract

Non-thermal plasma-based technologies have emerged as versatile tools for various industrial processes due to their ability to induce chemical reactions efficiently under ambient conditions. In particular, dielectric barrier discharges (DBDs) are of interest because of their robust and reliable design and scalability. This study investigates the role of pressure in tuning conversion, plasma parameters, and flow patterns in a plasma-assisted chemical reaction using a surface DBD (SDBD) reactor. The removal of O<inf>2</inf> traces in H<inf>2</inf> was used as a model reaction, where an unexpected increased conversion at elevated pressure was observed at high powers. This effect was studied using high-speed photography to analyze streamer dynamics and optical emission spectroscopy to determine plasma parameters. With increasing pressure, both the plasma area and the number of individual streamers decreased, and the electron density decreased as well. Fluid simulations were conducted to examine the impact of increased pressure on mass transport pointing to an enhanced contact time as the origin of the increased conversion at high dissipated powers. The findings highlight the importance of optimizing pressure and power conditions to maximize the efficiency of plasma-based chemical processes.