Ice-Shielding Models for Self-Preservation of Gas Hydrates  

作　　者：Tsutomu Uchlda Toshimitsu Sakurai Takeo Hondoh 

机构地区：[1]Division of Applied Physics, Faculty of Engineering, Hokkaido University, N13 W8 Kita-ku, Sapporo 060-8628, Japan [2]Institute for Laser Technology, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0817, Japan [3]Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo 060-0819, Japan

出　　处：《Journal of Chemistry and Chemical Engineering》2011年第8期691-705,共15页化学与化工（英文版）

摘　　要：The self-preservation of methane hydrate is a key process in its engineering applications because the hydrate can survive for a significant period under atmospheric pressure and moderate temperature. Some experiments have predicted that the shielding ice formed on the hydrate surface after initial dissociation of the hydrate plays an important role in the self-preservation effect. We propose ice-shielding models of gas hydrates to investigate the dissociation rates quantitatively, including the self-preservation process, at temperatures below the ice-melting point and at atmospheric pressure. Three general models are constructed for two temperature ranges The rate-determining process for the lower temperature range is hydrate dissociation, and those for the higher range are gas diffusion through ice or hydrate layers, which depend on the thickness of the shielding-ice layer. Our models suggest that the extent of self-preservation depends on temperature, original hydrate size, and guest substances, which can explain the experimental results.

关 键 词：SELF-PRESERVATION gas hydrate dissociation kinetics gas diffusion in solid. 

分 类 号：P744.4[天文地球—海洋科学] O53[理学—等离子体物理]