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Decomposition of methane hydrates in sand, sandstone, clays and glass beads
| Title: | Decomposition of methane hydrates in sand, sandstone, clays and glass beads |
| Authors: | Uchida, Tsutomu1 Browse this author →KAKEN DB | | Takeya, Satoshi Browse this author | | Chuvilin, Evgene M. Browse this author | | Ohmura, Ryo Browse this author | | Nagao, Jiro Browse this author | | Yakushev, Vladimir S. Browse this author | | Istomin, Vladimir A. Browse this author | | Minagawa, Hideki Browse this author | | Ebinuma, Takao Browse this author | | Narita, Hideo Browse this author |
| Authors(alt): | 内田, 努1 |
| Keywords: | Methane hydrate | | decomposition temperature shift | | natural sediment | | artificial fine particle | | pore space distribution | | water content |
| Issue Date: | 11-May-2004 |
| Publisher: | American Geophysical Union (AGU) |
| Journal Title: | Journal of Geophysical Research - Solid Earth (Chemistry and Physics of Minerals and Rocks/Volcanology) |
| Volume: | 109 |
| Issue: | B5 |
| Start Page: | B05206 |
| Publisher DOI: | 10.1029/2003JB002771 |
| Abstract: | Decomposition conditions of methane hydrates in sediments were measured during formation-decomposition cycles. As test sediments, we used silica sand, sandstone, and clays (kaoline and bentonite), which are typical natural materials known as hydrate bearing sediments, and the range of samples cover a range of water saturating abilities. To better understand the results, we also used uniformly sized glass beads. Pore effects on decomposition of these materials were investigated by analyzing the pore-space distributions of the materials and by varying the initial water content of the samples. The results obtained for sand and sandstone samples indicated that the final decomposition temperatures were shifted lower than those for bulk hydrates at the same pressure. Temperature shifts were more negative for smaller initial water contents with the maximum shift being approximately -0.5 K. The results were consistent with those measured for glass beads with nearly the same particle size. For kaoline clays, the shift was at most -1.5 K. We conclude that the decomposition conditions are mainly affected by the pore sizes. The surface textures and mineral components had less influence on the results. We confirmed that glass beads mimic the effect of sediments for sand, sandstone, and kaoline clays, which have little-to-no swelling when put in contact with water. On the other hand, for bentonite particles, the results indicated that methane hydrates formed not only between the particles but also in the interlayers. A thermodynamic promoting effect was found for dilute bentonite solutions, although the positive decomposition-temperature shift was at most +0.5 K. |
| Description: | An edited version of this paper was published by AGU. Copyright 2004 American Geophysical Union. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/436 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 内田 努
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