This study provided a model for calculating the aquifer transmissibility, the CO2 injection rate, the inner diameter of the injection well, and the number of wells for liquid CO2 disposal in the aquifer. The possibility of disposing liquid CO2 in an aquifer just beneath the sea floor was shown, based on the equilibrium lines in the pressure and temperature map. Our study focused on the feasibility of liquid CO2 disposal below the critical temperature because CO2 can be denser in the low-pressure range (below the critical temperature) than above the critical temperature. An aquifer about 200 m under the sea floor, at a water depth of around 500 m (700 m below the sea surface), will serve for liquid CO2 disposal. In the aquifer the absolute pressure is approximately 7.3 MPa, sea-floor temperature is about 4-6°C, and aquifer temperature is about 15-20°C. Therefore, it can be assumed that CO2 dissolves in the aquifer water, and liquid CO2 replaces the water. This means that under the previous conditions, more CO2 can be injected into the aquifer compared to supercritical conditions. Furthermore, by forming a cap of CO2 hydrates, the sediment between the sea floor and the aquifer, prevents CO2 leakage to the sea. Even without the cap, liquid CO2 and CO2 hydrates form at the sea floor, so the CO2 exerts no large environmental impact.
|ジャーナル||Annals of the New York Academy of Sciences|
|出版ステータス||出版済み - 1 1 2000|
All Science Journal Classification (ASJC) codes
- Global and Planetary Change
- Fuel Technology
- Fluid Flow and Transfer Processes