Gas Hydrate in Crystalline-Swelled Clay: The Effect of Pore Dimension on Hydrate Formation and Phase Equilibria

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• 作者：Daeok Kim ; Yun-Ho Ahn ; Se-Joon Kim ; Joo Yong Lee ; Jeahyoung Lee ; Young-ju Seo ; Huen Lee
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：September 24, 2015
• 年：2015
• 卷：119
• 期：38
• 页码：22148-22153
• 全文大小：398K
• ISSN：1932-7455

文摘

Understanding of gas hydrates, for example, phase equilibria, in reservoir sediments is one of the important issues in the fields of energy production and CO₂ sequestration via CH₄ hydrate exploitation and CO₂ hydrate formation. The composition of water in clay can change their physical properties, which influences the state in which gas hydrates exist in clays. We investigated gas hydrates in crystalline-swelled Na-montmorillonite (CS-mon) having water content of <27 wt % and maintaining crystallinity of clay particles. Instead of a gas hydrate forming in the interlayer, gas is dissolved in the swelled interlayers of clay, acting as a favorable storage site for hydrophilic CO₂. In addition, gas hydrates formed in CS-mon showed both inhibited and promoted phase behavior. This revealed that the clay surface can promote the formation of a hydrate structure, but confinement in nanosized space dominates the promotion effect and causes stronger inhibition than in the bulk phase. We believe that our results not only broaden the understanding of gas hydrates in confining systems and porous materials but also provide a precise explanation of the behavior of gas hydrates in clay sediment.