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

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.