Kinetic modelling of CO₂ conversion in gliding arc discharges: combining experiment and simulation

Gliding arc discharge (GAD), involving both equilibrium and non-equilibrium plasma stages, is regarded as a promising way to convert CO₂ in industry, owing to its high energy efficiency and large density of reactive particles. It is a long-standing challenge to characterise the complete evolution of various particles in GAD at different stages by a kinetic model. In this work, we propose a novel kinetic model by separating three stages, equilibrium, non-equilibrium, and post-discharge, in which experimental data on the plasma's macroscopic characteristics are used as input. The model is validated by comparing the final CO₂ conversion and vibrational temperatures. The results indicate that thermolysis of vibrational states offers a very high potential to split CO₂, but the subsequent recombination reactions, especially CO + O₂ → CO₂ + O, restrict the final CO₂ conversion performance.