CH4 Gas Extraction by CO2 : Substitution in Clathrate Hydrate through Bimolecular Iteration

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

3 Scopus Citations
View graph of relations

Author(s)

  • Xiao-Hui Yu
  • Yuan Liu
  • San-Ya Du
  • Xu Zheng
  • Jin-Long Zhu
  • Hong-Wu Xu
  • Jian-Zhong Zhang
  • Shi-Yu Du
  • J. S. Francisco
  • Chang-Qing Jin
  • Yu-Sheng Zhao
  • Hui Li

Detail(s)

Original languageEnglish
Article number048201
Journal / PublicationChinese Physics Letters
Volume37
Issue number4
Publication statusPublished - Apr 2020
Externally publishedYes

Abstract

Methane clathrate hydrate (MCH) is a promising energy resource, but controllable extraction of CH4 from MCH remains a challenge. Gradually replacing CH4 in MCH with CO2 is an attractive scheme, as it is cost efficient and mitigates the environmentally harmful effects of CO2 by sequestration. However, the practicable implementation of this method has not yet been achieved. In this study, using in situ neutron diffraction, we confirm that CH4 in the 51262 cages of bulk structure-I (sI) MCH can be substituted by gaseous CO2 under high pressure and low temperature with a high substitution ratio (∼44%) while conserving the structure of the hydrate framework. First-principles calculations indicate that CO2 binds more strongly to the 51262 cages than methane does, and that the diffusion barrier for CH4 is significantly lowered by an intermediate state in which one hydrate cage is doubly occupied by CH4 and CO2. Therefore, exchange of CO2 for CH4 in MCH is not only energetically favorable but also kinetically feasible. Experimental and theoretical studies of CH4/CO2 substitution elucidate a method to harness energy from these combustible ice resources.

Citation Format(s)

CH4 Gas Extraction by CO2: Substitution in Clathrate Hydrate through Bimolecular Iteration. / Yu, Xiao-Hui; Liu, Yuan; Du, San-Ya et al.
In: Chinese Physics Letters, Vol. 37, No. 4, 048201, 04.2020.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review