Interaction between CO2-rich acidic water, hydrated Portland cement and sedimentary rocks: Column experiments and reactive transport modeling
Percolation experiments, using columns filled with alternating layers of hydrated Portland cement and crushed sedimentary rocks, were conducted at PCO2 = 10 bar and 60 °C. Limestone, sandstone and marl were representative of reservoir and cap rocks for a geologic CO2 storage site. The injected solution was at equilibrium with gypsum and equilibrated with the CO2. The main reactions were the dissolution of the calcite that constitutes the rocks and the hydrotalcite and portlandite of the Portland cement. The resulting porewaters were supersaturated with respect to aragonite and gypsum, leading to their precipitation. 2D reactive transport simulations successfully reproduced the experimental aqueous chemistry changes caused by the major dissolution of calcite, portlandite and hydrotalcite together with the precipitation of aragonite, dolomite (cement carbonation), gypsum and alunite. Porosity increased to different extents in both cement and rock. Cement degradation was noticeable in all the cases, but even more in the sandstone experiment.
| Main Authors: | , , , , , |
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| Other Authors: | |
| Format: | artículo biblioteca |
| Language: | English |
| Published: |
Elsevier
2021-06-30
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| Subjects: | CO2 sequestration, Portlant Cement, Limestone, Sandstone, Marl, Reactive transport modeling, |
| Online Access: | http://hdl.handle.net/10261/236526 http://dx.doi.org/10.13039/501100003329 http://dx.doi.org/10.13039/501100004837 |
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| Summary: | Percolation experiments, using columns filled with alternating layers of hydrated Portland cement and crushed sedimentary rocks, were conducted at PCO2 = 10 bar and 60 °C. Limestone, sandstone and marl were representative of reservoir and cap rocks for a geologic CO2 storage site. The injected solution was at equilibrium with gypsum and equilibrated with the CO2. The main reactions were the dissolution of the calcite that constitutes the rocks and the hydrotalcite and portlandite of the Portland cement. The resulting porewaters were supersaturated with respect to aragonite and gypsum, leading to their precipitation.
2D reactive transport simulations successfully reproduced the experimental aqueous chemistry changes caused by the major dissolution of calcite, portlandite and hydrotalcite together with the precipitation of aragonite, dolomite (cement carbonation), gypsum and alunite. Porosity increased to different extents in both cement and rock. Cement degradation was noticeable in all the cases, but even more in the sandstone experiment. |
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