PROGRESS OF COSMOS (CO{sub}2 SENDING METHOD FOR OCEAN STORAGE) AND OACE (OCEAN ABYSSAL CARBON EXPERIMENT)

摘要

The storage of liquid CO{sub}2 at an ocean floor, one of promising measures to mitigate the global warming, requires 3500 m depth for the gravitationally stable storage, a breakthrough technology and a reasonable cost to realize, although it has large advantages such as the sequestration term longer than 2000 years. However CO{sub}2 can be sent to the ocean floor by shallow release, if we can use the nature that the cold CO{sub}2 to be shipped by a CO{sub}2 carrier is much denser than the ambient seawater even at shallow depths. The National Maritime Research Institute (NMRI) conducted several joint field CO{sub}2 release experiments with the Monterey Bay Aquarium Research Institute (MBARI, USA) since 1999 under the auspices of the NEDO, and proposed the improved COSMOS, CO{sub}2 Sending Method for Ocean Storage, in which G02 is released into 200 m depth as slurry masses (mixture of dry ice and cold liquid CO{sub}2). Since 2002, under the NEDO Grant, the NMRI started a new international joint research, OACE, Ocean Abyssal Carbon Experiment with tie MBARI and the University of Bergen (UoB, Norway), in order to accumulate the basic data on the long-term stability of stored CO{sub}2 and its environmental effects around storage site.