Effect of gas temperature on carbon soot oxidation via non-thermal plasma: two-dimensional numerical study integrating reactive flow and discharge models

Non-thermal plasma (NTP) efficiently regenerates diesel particulate filters by oxidizing carbon soot (CS) at low temperatures. However, numerical studies on the spatial characteristics of CS oxidation by NTP are scarce. In addition, the influence of background gas heating on the CS-oxidizing performance by NTP remains inadequately understood. This research investigates the impact of gas temperature (323–573 K) on heterogeneous CS oxidation using NTP in a two-dimensional configuration. The results indicate that CS is mainly oxidized by \({O}_{3}\) $O_3$ , \({NO}_{2}\) ${\mathit{NO}}_2$ , and \({O}_{2}\) $O_2$ during NTP treatment. The energy efficiency of CS removal by NTP ranges from 0.1 to 2.6 g kWh^–1 for varying gas temperature and applied voltage, consistent with previous research. Higher gas temperatures enhance both CS removal rate and efficiency, whereas higher applied voltages enhance rate at the expense of efficiency. The study also assesses energy conversion efficiency from electrical power input to chemical bonding energy during CS oxidation by NTP, yielding 0.03 to 0.23% efficiency for the considered gas temperature and voltage ranges, with higher temperatures leading to better efficiency.