X-ray Diffraction Study of K- and Ca-Exchanged Montmorillonites in CO2 Atmospheres
| Autor: | August F. Koster van Groos, Stephen Guggenheim, Andreas Busch, Paul A. Giesting |
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| Rok vydání: | 2012 |
| Předmět: |
Time Factors
Atmosphere Intercalation (chemistry) Kinetics Analytical chemistry Mineralogy General Chemistry Carbon Dioxide Chemical kinetics chemistry.chemical_compound Montmorillonite X-Ray Diffraction chemistry X-ray crystallography Bentonite Potassium medicine Environmental Chemistry Calcium Swelling medicine.symptom Absorption (chemistry) Clay minerals |
| Zdroj: | Environmental Science & Technology. 46:5623-5630 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/es3005865 |
| Popis: | Powder X-ray diffraction shows that K- and Ca-exchanged montmorillonites swell upon interacting with CO(2) at ambient temperatures, depending on their initial hydration state. K-exchanged montmorillonite swells rapidly to a maximum d(001) of ∼12.2 Å. In contrast, Ca-exchanged montmorillonite swells more slowly, but reaches a maximum d(001) of ∼15.1 Å. Reaction kinetics differ significantly between the K- and Ca-exchanged montmorillonite complexes. Expansion of K-exchanged montmorillonite samples was rapid, occurring on time scales of tens of minutes or less. The Ca-exchanged montmorillonite samples continued to expand over periods up to 42 h. Aging of both K- and Ca-exchanged montmorillonite complexes at elevated CO(2) pressure for 1-2 days resulted in greater stability when CO(2) pressure was released. The observed intercalation reactions have important consequences for carbon sequestration: (1) CO(2) absorption by swelling clays may represent a significant pathway for storage of CO(2). (2) The swelling of smectites under CO(2) pressure may have a significant impact on the permeability of caprock formations. |
| Databáze: | OpenAIRE |
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