Effect of Organic Matter on CO2 Hydrate Phase Equilibrium in Phyllosilicate Suspensions

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• 作者：Taehyung Park ; Daeseung Kyung ; Woojin Lee
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：June 17, 2014
• 年：2014
• 卷：48
• 期：12
• 页码：6597-6603
• 全文大小：383K
• 年卷期：v.48,no.12(June 17, 2014)
• ISSN：1520-5851

文摘

In this study, we examined various CO₂ hydrate phase equilibria under diverse, heterogeneous conditions, to provide basic knowledge for successful ocean CO₂ sequestration in offshore marine sediments. We investigated the effect of geochemical factors on CO₂ hydrate phase equilibrium. The three-phase (liquid鈥揾ydrate鈥搗apor) equilibrium of CO₂ hydrate in the presence of (i) organic matter (glycine, glucose, and urea), (ii) phyllosilicates [illite, kaolinite, and Na-montmorillonite (Na-MMT)], and (iii) mixtures of them was measured in the ranges of 274.5鈥?77.0 K and 14鈥?2 bar. Organic matter inhibited the phase equilibrium of CO₂ hydrate by association with water molecules. The inhibition effect decreased in the order: urea < glycine < glucose. Illite and kaolinite (unexpandable clays) barely affected the CO₂ hydrate phase equilibrium, while Na-MMT (expandable clay) affected the phase equilibrium because of its interlayer cations. The CO₂ hydrate equilibrium conditions, in the illite and kaolinite suspensions with organic matter, were very similar to those in the aqueous organic matter solutions. However, the equilibrium condition in the Na-MMT suspension with organic matter changed because of reduction of its inhibition effect by intercalated organic matter associated with cations in the Na-MMT interlayer.