| Autor: |
Bowers GM; Department of Chemistry and Biochemistry, St. Mary's College of Maryland, 47645 College Drive, St. Mary's City, Maryland 20686, United States., Loganathan N; Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States., Loring JS; Computational and Molecular Sciences Directorate, Pacific Northwest National Laboratory, 3335 Innovation Boulevard, Richland, Washington 99352, United States., Schaef HT; Computational and Molecular Sciences Directorate, Pacific Northwest National Laboratory, 3335 Innovation Boulevard, Richland, Washington 99352, United States., Yazaydin AO; Department of Chemical Engineering, University College London, London, U.K. WC1E 7JE. |
| Jazyk: |
angličtina |
| Zdroj: |
Accounts of chemical research [Acc Chem Res] 2023 Jul 04; Vol. 56 (13), pp. 1862-1871. Date of Electronic Publication: 2023 Jun 20. |
| DOI: |
10.1021/acs.accounts.3c00188 |
| Abstrakt: |
ConspectusIn the mid 2010s, high-pressure diffraction and spectroscopic tools opened a window into the molecular-scale behavior of fluids under the conditions of many CO 2 sequestration and shale/tight gas reservoirs, conditions where CO 2 and CH 4 are present as variably wet supercritical fluids. Integrating high-pressure spectroscopy and diffraction with molecular modeling has revealed much about the ways that supercritical CO 2 and CH 4 behave in reservoir components, particularly in the slit-shaped micro- and mesopores of layered silicates (phyllosilicates) abundant in caprocks and shales. This Account summarizes how supercritical CO 2 and CH 4 behave in the slit pores of swelling phyllosilicates as functions of the H 2 O activity, framework structural features, and charge-balancing cation properties at 90 bar and 323 K, conditions similar to a reservoir at ∼1 km depth. Slit pores containing cations with large radii, low hydration energy, and large polarizability readily interact with CO 2 , allowing CO 2 and H 2 O to adsorb and coexist in these interlayer pores over a wide range of fluid humidities. In contrast, cations with small radii, high hydration energy, and low polarizability weakly interact with CO 2 , leading to reduced CO 2 uptake and a tendency to exclude CO 2 from interlayers when H 2 O is abundant. The reorientation dynamics of confined CO 2 depends on the interlayer pore height, which is strongly influenced by the cation properties, framework properties, and fluid humidity. The silicate structural framework also influences CO 2 uptake and behavior; for example, smectites with increasing F-for-OH substitution in the framework take up greater quantities of CO 2 . Reactions that trap CO 2 in carbonate phases have been observed in thin H 2 O films near smectite surfaces, including a dissolution-reprecipitation mechanism when the edge surface area is large and an ion exchange-precipitation mechanism when the interlayer cation can form a highly insoluble carbonate. In contrast, supercritical CH 4 does not readily associate with cations, does not react with smectites, and is only incorporated into interlayer slit mesopores when (i) the pore has a z -dimension large enough to accommodate CH 4 , (ii) the smectite has low charge, and (iii) the H 2 O activity is low. The adsorption and displacement of CH 4 by CO 2 and vice versa have been studied on the molecular scale in one shale, but opportunities remain to examine behavioral details in this more complicated, slit-pore inclusive system. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
