In Situ Molecular Spectroscopic Evidence for CO2 Intercalation into Montmorillonite in Supercritical Carbon Dioxide

详细信息    查看全文

• 作者：John S. Loring ; Herbert T. Schaef ; Romulus V. F. Turcu ; Christopher J. Thompson ; Quin R. S. Miller ; Paul F. Martin ; Jianzhi Hu ; David W. Hoyt ; Odeta Qafoku ; Eugene S. Ilton ; Andrew R. Felmy ; Kevin M. Rosso
• 刊名：Langmuir
• 出版年：2012
• 出版时间：May 8, 2012
• 年：2012
• 卷：28
• 期：18
• 页码：7125-7128
• 全文大小：226K
• 年卷期：v.28,no.18(May 8, 2012)
• ISSN：1520-5827

文摘

The interaction of anhydrous supercritical CO₂ (scCO₂) with both kaolinite and 1W (i.e., close to but less than one layer of hydration) calcium-saturated montmorillonite was investigated under conditions relevant to geologic carbon sequestration (50 掳C and 90 bar). The CO₂ molecular environment was probed in situ using a combination of three novel high-pressure techniques: X-ray diffraction, magic angle spinning nuclear magnetic resonance spectroscopy, and attenuated total reflection infrared spectroscopy. We report the first direct evidence that the expansion of montmorillonite under scCO₂ conditions is due to CO₂ migration into the interlayer. Intercalated CO₂ molecules are rotationally constrained and do not appear to react with waters to form bicarbonate or carbonic acid. In contrast, CO₂ does not intercalate into kaolinite. The findings show that predicting the seal integrity of caprock will have complex dependence on clay mineralogy and hydration state.