Abstract:
Geologic carbon sequestration is the capture of anthropogenic carbon dioxide (CO2) and its storage in deep geologic formations. The processes of CO2 seepage into surface water after migration through water-saturated sediments are reviewed. Natural CO2 and CH 4 fluxes are pervasive in surface-water environments and are good analogues to potential leakage and seepage of CO2. Buoyancy-driven bubble rise in surface water reaches a maximum velocity of approximately 30 cm s-1. CO2 rise in saturated porous media tends to occur as channel flow rather than bubble flow. A comparison of ebullition versus dispersive gas transport for CO2 and CH4 shows that bubble flow will dominate over dispersion in surface water. Gaseous CO2 solubility in variable-salinity waters decreases as pressure decreases leading to greater likelihood of ebullition and bubble flow in surface water as CO 2 migrates upward. © Springer-Verlag 2006.
