Abstract
Carbon capture and sequestration (CCS) is part of the global challenge to mitigating global warming and climate change. Geological sequestration of carbon dioxide (CO2) is an immediately available and technologically feasible method for achieving a substantial reduction in carbon dioxide emissions into the atmosphere. Because injected CO2 migrates upward in an aquifer owing to the buoyancy force, a highly impermeable layer is generally employed to prevent CO2 leakage from the storage reservoirs. For these reasons, assessment of the storage site, leakage risks, and storage costs are one of the main issues in CO2 geological sequestration. The intent of the present study is to clarify the fundamental mechanism of buoyancy driven CO2 in a porous media. The behaviour of liquid CO2 in water-saturated silica packed bed was observed using high spatial resolution X-ray computed tomography. As the result, CO2 migration in porous media was visualized with 20 μm resolution, and it was found that the CO2 migration speed was mostly dominated not by the viscous resistance of CO2 itself but by that of the surrounding water.
