Structural stability of methane hydrate at high pressures
The structural stability of methane hydrate under pressure at room temperature was examined by both in-situ single-crystal and powder X-ray diffraction techniques on samples with structure types I, II, and H in diamond-anvil cells. The diffraction data for types II (sII) and H (sH) were refined to t...
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| Format: | Article |
| Language: | English |
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Elsevier
2011-01-01
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| Series: | Geoscience Frontiers |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1674987110000344 |
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| author | Jinfu Shu Xiaojia Chen I.-Ming Chou Wenge Yang Jingzhu Hu Russell J. Hemley Ho-kwang Mao |
| author_facet | Jinfu Shu Xiaojia Chen I.-Ming Chou Wenge Yang Jingzhu Hu Russell J. Hemley Ho-kwang Mao |
| author_sort | Jinfu Shu |
| collection | DOAJ |
| description | The structural stability of methane hydrate under pressure at room temperature was examined by both in-situ single-crystal and powder X-ray diffraction techniques on samples with structure types I, II, and H in diamond-anvil cells. The diffraction data for types II (sII) and H (sH) were refined to the known structures with space groups Fd3m and P63/mmc, respectively. Upon compression, sI methane hydrate transforms to the sII phase at 120 MPa, and then to the sH phase at 600 MPa. The sII methane hydrate was found to coexist locally with sI phase up to 500 MPa and with sH phase up to 600 MPa. The pure sH structure was found to be stable between 600 and 900 MPa. Methane hydrate decomposes at pressures above 3 GPa to form methane with the orientationally disordered Fm3m structure and ice VII (Pn3m). The results highlight the role of guest (CH4)-host (H2O) interactions in the stabilization of the hydrate structures under pressure. |
| first_indexed | 2024-03-12T05:56:43Z |
| format | Article |
| id | doaj.art-a637416fd55044859dd689a310d6fd15 |
| institution | Directory Open Access Journal |
| issn | 1674-9871 |
| language | English |
| last_indexed | 2024-03-12T05:56:43Z |
| publishDate | 2011-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Geoscience Frontiers |
| spelling | doaj.art-a637416fd55044859dd689a310d6fd152023-09-03T04:30:54ZengElsevierGeoscience Frontiers1674-98712011-01-01219310010.1016/j.gsf.2010.12.001Structural stability of methane hydrate at high pressuresJinfu Shu0Xiaojia Chen1I.-Ming Chou2Wenge Yang3Jingzhu Hu4Russell J. Hemley5Ho-kwang Mao6Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USAGeophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA954 National Center, U.S. Geological Survey, Reston, VA 20192, USAHPSynC, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, IL 60439, USANational Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973, USAGeophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USAGeophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USAThe structural stability of methane hydrate under pressure at room temperature was examined by both in-situ single-crystal and powder X-ray diffraction techniques on samples with structure types I, II, and H in diamond-anvil cells. The diffraction data for types II (sII) and H (sH) were refined to the known structures with space groups Fd3m and P63/mmc, respectively. Upon compression, sI methane hydrate transforms to the sII phase at 120 MPa, and then to the sH phase at 600 MPa. The sII methane hydrate was found to coexist locally with sI phase up to 500 MPa and with sH phase up to 600 MPa. The pure sH structure was found to be stable between 600 and 900 MPa. Methane hydrate decomposes at pressures above 3 GPa to form methane with the orientationally disordered Fm3m structure and ice VII (Pn3m). The results highlight the role of guest (CH4)-host (H2O) interactions in the stabilization of the hydrate structures under pressure.http://www.sciencedirect.com/science/article/pii/S1674987110000344Methane hydrateStructural stabilityHigh pressure |
| spellingShingle | Jinfu Shu Xiaojia Chen I.-Ming Chou Wenge Yang Jingzhu Hu Russell J. Hemley Ho-kwang Mao Structural stability of methane hydrate at high pressures Geoscience Frontiers Methane hydrate Structural stability High pressure |
| title | Structural stability of methane hydrate at high pressures |
| title_full | Structural stability of methane hydrate at high pressures |
| title_fullStr | Structural stability of methane hydrate at high pressures |
| title_full_unstemmed | Structural stability of methane hydrate at high pressures |
| title_short | Structural stability of methane hydrate at high pressures |
| title_sort | structural stability of methane hydrate at high pressures |
| topic | Methane hydrate Structural stability High pressure |
| url | http://www.sciencedirect.com/science/article/pii/S1674987110000344 |
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