In Situ Molecular Spectroscopic Evidence for CO2 Intercalation into Montmorillonite in Supercritical Carbon Dioxide
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- 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 CO<sub>2sub> (scCO<sub>2sub>) 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 CO<sub>2sub> 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 scCO<sub>2sub> conditions is due to CO<sub>2sub> migration into the interlayer. Intercalated CO<sub>2sub> molecules are rotationally constrained and do not appear to react with waters to form bicarbonate or carbonic acid. In contrast, CO<sub>2sub> 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.