Numerical study of CO2 hydrate dissolution rates in the ocean: Effect of pressure, temperature, and salinity

Abstract

In this study, we numerically investigated the effect of pressure (100-250 bar), temperature (274-288 K), and salinity (3.5% w/w electrolytes) on CO2 hydrate dissolution rates in the ocean. Mass transfer equations and CO2 solubility data were used to estimate the CO2 hydrate dissolution rates. The higher pressure and lower temperature significantly reduced the CO2 hydrate dissolution rates due to the increase of CO2 particle density. In the high salinity condition, the rates of CO2 hydrate dissolution were decreased compared to pure water control. This is due to decrease of CO2 solubility in surrounding water, thus reducing the mass transfer of CO2 from the hydrate particle to CO2 under-saturated water. The results obtained from this study could provide fundamental knowledge to slow down or prevent the CO2 hydrate dissolution for long-term stable CO2 storage in the ocean as a form of CO2 hydrate.