The Impact of CO₂ Clathrate Hydrate on Deep Ocean Sequestration of CO₂: Experimental Observations and Modeling Results

A bstract : CO 2 clathrate hydrate is a crystalline compound that can form under temperature and pressure conditions associated with the injection and storage of CO 2 in the deep ocean (below 500 m). At depths being considered for injection of CO 2 (between 1,000 and 1,500 m), in the absence of hydrate formation, the buoyant CO 2 would simply rise as it dissolved in the seawater. If, however, the hydrate phase forms, it will affect this process. The impact could be positive or negative, depending on how hydrate forms and whether it is associated with undissolved CO 2 . This paper summarizes experimental and theoretical information relating to formation conditions for the hydrate, the relative density of the hydrate, the formation of a hydrate shell on drops of liquid CO 2 , and the impact that a hydrate shell has on dissolution of CO 2 . The future direction of the work is also briefly described.