A molecular level-based parametric study on the capture of hydrogen sulfide and carbon oxides from flue gas mixtures using Au nanopores

ABSTRACT

Identifying a means of effectively separating and adsorbing the harmful constituents from flue gas emissions is always crucial for the protection of human health and the environment. All-atom molecular dynamics were employed to analyze the dynamic behaviour of flue gas molecules in Au nanopores. The influences of various system temperatures, gas concentrations, and pore sizes on the adsorption conformation, diffusion coefficient, average adsorption energy, and adsorption probability of the flue gases inside an Au nanopore were examined. Results showed that when the temperature rose to 300∼400 K, the gaseous H₂S constituent in the flue gas was swiftly adsorbed to the nanopore walls due to the strong H₂S-Au interactions, enabling an effective separation of H₂S from the flue gas. In addition, increases in pore size (d ≥ 40 Å) reduced the adsorption probability of CO₂ and CO on the nanopore surfaces, which also promoted constituent separations of H₂S from the flue gas. When the concentration of flue gas exceeded 6.6 mol/L, hydrogen bonds of H₂O clusters and their networks entangled, impeding molecular diffusion and thereby reducing the functionality of nanopore-trapping molecules. The results presented in this paper provide a valuable reference for filter material design for flue gas depuration.

GRAPHICAL ABSTRACT

KEYWORDS:

• Flue gas
• hydrogen sulfide
• carbon oxides
• nanopores

Acknowledgements

The authors gratefully acknowledge the financial support provided for this research by the Ministry of Science and Technology, R.O.C.. We also thank to National Center for High-performance Computing (NCHC) of National Applied Research Laboratories (NARLabs) in Taiwan for providing computational and storage resources.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Availability of data and material

All data generated or analyzed during this work are included in this published article.

Authors’ contributions

Jenn-Kun Kuo: Conceptualization, Formal analysis, Writing. Pei-Hsing Huang: Supervision & Proofreading. Chao-Cheng Cheng: Investigation. Chien-Hui Lee: drawing & Editing.

Additional information

Funding

This research was funded by the Ministry of Science and Technology, R.O.C. under grants MOST 111-2221-E-224-037 and MOST 110-2221-E-224-031.