Chapter 6 - An analysis of the disposal of anthropogenic CO2 in the ocean via a submerged hydrate crystallizer

Abstract

This chapter presents an analysis of the disposal of anthropogenic CO2 in the ocean via a submerged hydrate crystallizer. The reactor employed for analysis had a Pyrex-glass tube inside with a 100 mm inner diameter, 5 mm wall thickness, and 250 mm length, and an outside polycarbonate tube with a 120 mm inner diameter, 60 mm thickness, and 250 mm length. The typical experimental pressure and temperature were 45 bar and 6°C respectively, which simulated the pressure and temperature of seawater at 450 m in the ocean. The results showed that CO2 hydrate particles could be formed from a liquid CO2-water two-phase system with a limited induction period. As long as a proper agitation is performed, the hydrate particles produced would be negatively buoyant, and such particles would sink in the ocean. The hydrate particles released from the crystallizer being denser than seawater would descend to the ocean bottom. During this sinking process, the hydrate particles would dissolve slowly in the ocean because the hydrate is chemically unstable in seawater that is highly unsaturated with CO2.