title: Selective Encaging of N2O in N2O-N2Binary Gas Hydrates via Hydrate-Based Gas Separation.
abstract: The crystal structure and guest inclusion behaviors of nitrous oxide-nitrogen (N2O-N2) binary gas hydrates formed from N2O/N2gas mixtures are determined through spectroscopic analysis. Powder X-ray diffraction results indicate that the crystal structure of all the N2O-N2binary gas hydrates is identified as the structure I (sI) hydrate. Raman spectra for the N2O-N2binary gas hydrate formed from N2O/N2(80/20, 60/40, 40/60 mol %) gas mixtures reveal that N2O molecules occupy both large and small cages of the sI hydrate. In contrast, there is a single Raman band of N2O molecules for the N2O-N2binary gas hydrate formed from the N2O/N2(20/80 mol %) gas mixture, indicating that N2O molecules are trapped in only large cages of the sI hydrate. From temperature-dependent Raman spectra and the Predictive Soave-Redlich-Kwong (PSRK) model calculation, we confirm the self-preservation of N2O-N2binary gas hydrates in the temperature range of 210-270 K. Both the experimental measurements and the PSRK model calculations demonstrate the preferential occupation of N2O molecules rather than N2molecules in the hydrate cages, leading to a possible process for separating N2O from gas mixtures via hydrate formation. The phase equilibrium conditions, pseudo-pressure-composition (P-x) diagram, and gas storage capacity of N2O-N2binary gas hydrates are discussed in detail.
authors.forename: Youjeong
authors.initials: Y
authors.lastname: Yang
authors.forename: Donghoon
authors.initials: D
authors.lastname: Shin
authors.forename: Seunghyun
authors.initials: S
authors.lastname: Choi
authors.forename: Yesol
authors.initials: Y
authors.lastname: Woo
authors.affiliation: Department of Environmental Engineering, Kongju National University , Chungnam 330-717, Korea.
authors.forename: Jong-Won
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Marine Chemistry & Geochemistry Research Center, Korea Institute of Ocean Science and Technology , Gyeonggi-do 15627, Korea.
authors.forename: Dongseon
authors.initials: D
authors.lastname: Kim
authors.affiliation: Center for Carbon Mineralization, Korea Institute of Geoscience and Mineral Resources , Daejeon 305-350, Korea.
authors.forename: Hee-Young
authors.initials: HY
authors.lastname: Shin
authors.affiliation: Department of Energy and Resources Engineering, Kangwon National University , Chuncheon 200-701, Korea.
authors.forename: Minjun
authors.initials: M
authors.lastname: Cha
authors.affiliation: Marine Chemistry & Geochemistry Research Center, Korea Institute of Ocean Science and Technology , Gyeonggi-do 15627, Korea.
authors.forename: Ji-Ho
authors.identifier: 0000-0002-0234-9367
authors.initials: JH
authors.lastname: Yoon
mesh_terms: D005740:Gases / Q000737:chemistry; D011312:Pressure; D013059:Spectrum Analysis, Raman; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D005740:Gases; D014867:Water