| 摘要 |
A liquid CO2 injection system produces a negatively buoyant consolidated stream of liquid CO2, CO2 hydrate, and water that sinks upon release at ocean depths in the range of 700-1500 m. In this approach, seawater at a predetermined ocean depth is mixed with the liquid CO2 stream before release into the ocean. Because mixing is conducted at depths where pressures and temperatures are suitable for CO2 hydrate formation, the consolidated stream issuing from the injector is negatively buoyant, and comprises mixed CO2-hydrate/CO2-liquid/water phases. The "sinking" characteristic of the produced stream will prolong the metastability of CO2 ocean sequestration by reducing the CO2 dissolution rate into water. Furthermore, the deeper the CO2 hydrate stream sinks after injection, the more stable it becomes internally, the deeper it is dissolved, and the more dispersed is the resulting CO2 plume. These factors increase efficiency, increase the residence time of CO2 in the ocean, and decrease the cost of CO2 sequestration while reducing deleterious impacts of free CO2 gas in ocean water.
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