In Situ Infrared Spectroscopic Study of Forsterite Carbonation in Wet Supercritical CO2

详细信息    查看全文

• 作者：John S. Loring ; Christopher J. Thompson ; Zheming Wang ; Alan G. Joly ; Deborah S. Sklarew ; H. Todd Schaef ; Eugene S. Ilton ; Kevin M. Rosso ; Andrew R. Felmy
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：July 15, 2011
• 年：2011
• 卷：45
• 期：14
• 页码：6204-6210
• 全文大小：896K
• 年卷期：v.45,no.14(July 15, 2011)
• ISSN：1520-5851

文摘

Carbonation reactions are central to the prospect of CO₂ trapping by mineralization in geologic reservoirs. In contrast to the relevant aqueous-mediated reactions, little is known about the propensity for carbonation in the key partner fluid: supercritical carbon dioxide containing dissolved water (鈥渨et鈥?scCO₂). We employed in situ mid-infrared spectroscopy to follow the reaction of a model silicate mineral (forsterite, Mg₂SiO₄) for 24 h with wet scCO₂ at 50 掳C and 180 atm. The results show a dramatic dependence of reactivity on water concentration and the presence of liquid water on the forsterite particles. Exposure to neat scCO₂ showed no detectable carbonation reaction. At 47% and 81% water saturation, an 脜ngstrom-thick liquid-like water film was detected on the forsterite particles and less than 1% of the forsterite transformed. Most of the reaction occurred within the first 3 h of exposure to the fluid. In experiments at 95% saturation and with an excess of water (36% above water saturation), a nanometer-thick water film was detected, and the carbonation reaction proceeded continuously with approximately 2% and 10% conversion, respectively. Our collective results suggest constitutive links between water concentration, water film formation, reaction rate and extent, and reaction products in wet scCO₂.