CO₂ Ocean Sequestration and CO₂ Hydrate

Abstract

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.