Effective reduction on flame soot via plasma coupled with carbon dioxide

Dandan Qi; Mingxiao Chen; Kaixuan Yang; Tianjiao Li; Yaoyao Ying; Dong Liu

doi:10.1016/j.jhazmat.2024.133669

Effective reduction on flame soot via plasma coupled with carbon dioxide

J Hazard Mater. 2024 Mar 15:466:133669. doi: 10.1016/j.jhazmat.2024.133669. Epub 2024 Feb 1.

Authors

Dandan Qi¹, Mingxiao Chen¹, Kaixuan Yang¹, Tianjiao Li¹, Yaoyao Ying¹, Dong Liu²

Affiliations

¹ MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, People's Republic of China; Advanced Combustion Laboratory, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, People's Republic of China.
² MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, People's Republic of China; Advanced Combustion Laboratory, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, People's Republic of China. Electronic address: dongliu@njust.edu.cn.

PMID: 38310061
DOI: 10.1016/j.jhazmat.2024.133669

Abstract

This study explored the impact of non-thermal plasma and CO₂ on the flame soot characteristics within the diffusion flames. We analyzed on flame structures that were diluted with either CO₂ or N₂, temperature distributions, and soot characteristics, both in the presence and absence of plasma. Due to the higher specific heat capacity of CO₂ compared to N₂, the optical observations consistently showed lower temperatures in flames diluted with CO₂ as compared to those diluted with N₂. The inclusion of plasma and carbon dioxide resulted in the lowest soot concentration, indicating that plasma coupled with CO₂ has a synergistic inhibitory effect on soot emissions. The findings revealed that when CO₂ was used to dilute the flames and the oxygen concentration was low, the soot nanostructure appeared amorphous. Raman results showed that the level of graphitization observed in soot particles from CO₂ dilution flames was lower than that from N₂ dilution flames. In the presence of plasma and CO₂, the soot obtained exhibited the shortest fringe length and the highest fringe tortuosity. Significant correlations were observed between the nanostructure of soot and its reactivity. The combined application of plasma and CO₂ proved to be effective in reducing the soot carbonization degree.

Keywords: CO(2) addition; Diffusion flame; Plasma; Soot characteristics.