Research and Development on Carbon Dioxide (CO2) Storage on Deep Seabed

CO
₂
ocean storage is one of greenhouse gas control technologies, where CO
₂
is captured from flue gas of fossil fuels and is stored on deep seabed below the depth of 3500 meters to be sequestered from the atmosphere. The authors have worked for development of a CO
₂
sending method for the ocean storage; New COSMOS, where liquid CO
₂
mixed with dry ice is to be released at the depth of 500 meters to naturally sink to the deep seabed. Since 2005, the authors have started on a new joint research project for fundamental technology development of floating CO
₂
injection system for the New COSMOS in cooperation with National Institute of Advanced Industrial Science and Technology and IHI Marine United Inc. In this paper, after introducing the outline of the project, the authors will report progress in the studies including the results of (1) model test conducted to check the response of an offshore floating structure for CO
₂
injection in regular waves, and (2) lab experiments conducted to develop the device for successfully injection CO
₂
slurry drops with no growth of blocking plugs in the CO
₂
injection tube and the releasing nozzle.