Visualization of gaseous and dissolved CO2 migration in porous media
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Visualization experiments using a rectangular transparent acrylic cell, which contained glass beads saturated with alkaline solution, with a universal pH indicator, were conducted to investigate the migration behaviors of gas and dissolved CO2 in water-saturated porous media, assuming that CO2 exsolution occurs from the CO2-saturated groundwater. Immediately after the CO2 gas injection (t < 1 s), which is comparable to the period immediately following CO2 exsolution, CO2 gas moved upward, percolating into the pores through various pathways. During CO2 gas injection (t > 1 s), CO2 gas bubbles continued to move upward to the interface between the saturated porous medium and air, while dissolving in the pore water. When the CO2 gas reached the interface, a thin, dense yellow layer was formed, followed by the gradual coalescing of the small fingers, forming a thick dense yellow layer, indicating density-driven convection. The fingers formed by the density-driven convective flow were clearer in the coarser glass beads. The migration of carbonated water was faster, as the glass bead size and the CO2 gas injection rate increased, causing earlier CO2 saturation in pore water. The temporal changes in the effluent CO2 gas concentration, emitted from the saturated glass beads to air, varied with the grain size of the porous medium and the CO2 gas injection rate.
KeywordsCO2 Porous media Convection Visualization pH indicator
This research was supported by the Korea Ministry of Environment (MOE) under the “K-COSEM Research Program” and the National Research Foundation (NRF-2017R1A2B4008238) of the Ministry of Science, ICT and Future Panning, Korea.
- ASTM D 422–63 (2007) Standard test method for particle-size analysis of soils. ASTM International, West Conshohocken, PAGoogle Scholar
- ASTM D 6836–16 (2016) Standard test method for determination of the soil water characteristic curve for desorption using hanging column, pressure extractor, chilled mirror hygrometer, or centrifuge. ASTM International, West Conshohocken, PAGoogle Scholar
- Bang ES, Son JS, Santamarina JC (2012) Subsurface CO2 leakage: lab-scale study of salient characteristics and assessment of borehole-based detection using resistivity tomography. In: 4th International Conference on Geotechnical and Geophysical Site Characterization (ISC’4)Google Scholar
- Cihan A, Corapcioglu MY (2008) The effect of compressibility on the rise velocity of an air bubble in porous media. Water Resour Res 44(W04409):1–8Google Scholar
- Corapcioglu MY, Cihan A, Drazenovic M (2004) Rise velocity of an air bubble in porous media: theoretical studies. Water Resour Res 40(W04214):1–9Google Scholar
- Geistilinger H, Krauss G, Lazik D, Luckner L (2006) Direct gas injection into saturated glass beads: transition from incoherent to coherent gas flow pattern. Water Resour Res 42:W07403Google Scholar
- IEA/OECD (2008) CO2 capture and storage—a key carbon abatement option. Organisation for Economic Co-operation and Development & International Energy Agency, Paris, p 266Google Scholar
- IPCC (2007) Climate change 2007: Synthesis report. In: Pachauri RK, Reisinger A (eds) IPCC, Geneva, p 104Google Scholar
- Zhao K (2010) Experimental investigation of air injection in saturated unconsolidated porous media. University of Science and Technology of China, GuangdongGoogle Scholar