2002 年 12 巻 1 号 p. 40-49
CO2 ocean sequestration, which is thought to be a promising measure to mitigate global warming, can be classified mainly into the dissolution and the storage methods. On the evaluation of these measures, CO2 hydrate plays an important role, because CO2 becomes a hydrate in the ocean deeper than 500 m (North Pacific Ocean)∼900 m (North Atlantic Ocean). The solubility of CO2 shows a dual nature (solid and liquid solubilities) in the hydrate forming region. Two types of unexpected hydrate membrane strength just below the dissociation temperature and in a CO2 saturated solution, and the rebuilding process under stressed conditions greatly influence the above two CO2 ocean sequestration methods.