Methane hydrate formation and decomposition: Structural studies via neutron diffraction and empirical potential structure refinement
Neutron diffraction studies with hydrogen/deuterium isotope substitution measurements are performed to investigate the water structure at the early, medium, and late periods of methane clathrate hydrate formation and decomposition. These measurements are coupled with simultaneous gas consumption mea...
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craippubl:10.1063/1.2191056 2024-09-30T14:38:30+00:00 Methane hydrate formation and decomposition: Structural studies via neutron diffraction and empirical potential structure refinement Thompson, Helen Soper, Alan K. Buchanan, Piers Aldiwan, Nawaf Creek, Jefferson L. Koh, Carolyn A. 2006 http://dx.doi.org/10.1063/1.2191056 https://pubs.aip.org/aip/jcp/article-pdf/doi/10.1063/1.2191056/15384062/164508_1_online.pdf en eng AIP Publishing The Journal of Chemical Physics volume 124, issue 16 ISSN 0021-9606 1089-7690 journal-article 2006 craippubl https://doi.org/10.1063/1.2191056 2024-09-12T04:05:15Z Neutron diffraction studies with hydrogen/deuterium isotope substitution measurements are performed to investigate the water structure at the early, medium, and late periods of methane clathrate hydrate formation and decomposition. These measurements are coupled with simultaneous gas consumption measurements to track the formation of methane hydrate from a gas/water mixture, and then the complete decomposition of hydrate. Empirical potential structure refinement computer simulations are used to analyze the neutron diffraction data and extract from the data the water structure in the bulk methane hydrate solution. The results highlight the significant changes in the water structure of the remaining liquid at various stages of hydrate formation and decomposition, and give further insight into the way in which hydrates form. The results also have important implications on the memory effect, suggesting that the water structure in the presence of hydrate crystallites is significantly different at equivalent stages of forming compared to decomposing. These results are in sharp contrast to the previously reported cases when all remaining hydrate crystallites are absent from the solution. For these systems there is no detectable change in the water structure or the methane hydration shell before hydrate formation and after decomposition. Based on the new results presented in this paper, it is clear that the local water structure is affected by the presence of hydrate crystallites, which may in turn be responsible for the “history” or “memory” effect where the production of hydrate from a solution of formed and then subsequently melted hydrate is reportedly much quicker than producing hydrate from a fresh water/gas mixture. Article in Journal/Newspaper Methane hydrate AIP Publishing The Journal of Chemical Physics 124 16 164508 |
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description |
Neutron diffraction studies with hydrogen/deuterium isotope substitution measurements are performed to investigate the water structure at the early, medium, and late periods of methane clathrate hydrate formation and decomposition. These measurements are coupled with simultaneous gas consumption measurements to track the formation of methane hydrate from a gas/water mixture, and then the complete decomposition of hydrate. Empirical potential structure refinement computer simulations are used to analyze the neutron diffraction data and extract from the data the water structure in the bulk methane hydrate solution. The results highlight the significant changes in the water structure of the remaining liquid at various stages of hydrate formation and decomposition, and give further insight into the way in which hydrates form. The results also have important implications on the memory effect, suggesting that the water structure in the presence of hydrate crystallites is significantly different at equivalent stages of forming compared to decomposing. These results are in sharp contrast to the previously reported cases when all remaining hydrate crystallites are absent from the solution. For these systems there is no detectable change in the water structure or the methane hydration shell before hydrate formation and after decomposition. Based on the new results presented in this paper, it is clear that the local water structure is affected by the presence of hydrate crystallites, which may in turn be responsible for the “history” or “memory” effect where the production of hydrate from a solution of formed and then subsequently melted hydrate is reportedly much quicker than producing hydrate from a fresh water/gas mixture. |
format |
Article in Journal/Newspaper |
author |
Thompson, Helen Soper, Alan K. Buchanan, Piers Aldiwan, Nawaf Creek, Jefferson L. Koh, Carolyn A. |
spellingShingle |
Thompson, Helen Soper, Alan K. Buchanan, Piers Aldiwan, Nawaf Creek, Jefferson L. Koh, Carolyn A. Methane hydrate formation and decomposition: Structural studies via neutron diffraction and empirical potential structure refinement |
author_facet |
Thompson, Helen Soper, Alan K. Buchanan, Piers Aldiwan, Nawaf Creek, Jefferson L. Koh, Carolyn A. |
author_sort |
Thompson, Helen |
title |
Methane hydrate formation and decomposition: Structural studies via neutron diffraction and empirical potential structure refinement |
title_short |
Methane hydrate formation and decomposition: Structural studies via neutron diffraction and empirical potential structure refinement |
title_full |
Methane hydrate formation and decomposition: Structural studies via neutron diffraction and empirical potential structure refinement |
title_fullStr |
Methane hydrate formation and decomposition: Structural studies via neutron diffraction and empirical potential structure refinement |
title_full_unstemmed |
Methane hydrate formation and decomposition: Structural studies via neutron diffraction and empirical potential structure refinement |
title_sort |
methane hydrate formation and decomposition: structural studies via neutron diffraction and empirical potential structure refinement |
publisher |
AIP Publishing |
publishDate |
2006 |
url |
http://dx.doi.org/10.1063/1.2191056 https://pubs.aip.org/aip/jcp/article-pdf/doi/10.1063/1.2191056/15384062/164508_1_online.pdf |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_source |
The Journal of Chemical Physics volume 124, issue 16 ISSN 0021-9606 1089-7690 |
op_doi |
https://doi.org/10.1063/1.2191056 |
container_title |
The Journal of Chemical Physics |
container_volume |
124 |
container_issue |
16 |
container_start_page |
164508 |
_version_ |
1811641126365429760 |