Understanding the Pathway of Gas Hydrate Formation with Porous Materials for Enhanced Gas Separation
Jia Liu,
Yajuan Wei,
Wei Meng,
Pei-Zhou Li,
Yanli Zhao,
Ruqiang Zou
Affiliations
Jia Liu
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore; Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China
Yajuan Wei
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore; School of Chemistry, Nankai University, Tianjin 300071, China
Wei Meng
Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
Pei-Zhou Li
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore
Yanli Zhao
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore
Ruqiang Zou
Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
The reason that the stoichiometry of gas to water in artificial gas hydrates formed on porous materials is much higher than that in nature is still ambiguous. Fortunately, based on our experimental thermodynamic and kinetic study on the gas hydrate formation behavior with classic ordered mesoporous carbon CMK-3 and irregular porous activated carbon combined with density functional theory calculations, we discover a microscopic pathway of the gas hydrate formation on porous materials. Two interesting processes including (I) the replacement of water adsorbed on the carbon surface by gas and (II) further replacement of water in the pore by gas accompanied with the gas condensation in the pore and growth of gas hydrate crystals out of the pore were deduced. As a result, a great enhancement of the selectivity and regeneration for gas separation was achieved by controlling the gas hydrate formation behavior accurately.
