Study of CO2 Hydrate Formation in Saline Water for Oceanic CO2 Sequestration

Global warming and greenhouse gas emission has increased rapidly in the recent decades, which has lead to severe consequences such as global warming, rising sea levels, and permafrost depletion. One of the possible solutions to confront the global warming issue is to store greenhouse CO2 in oceanic conditions in the form of gas hydrates. Large-scale CO2 capture and storage technologies can restrict global temperature rise below 2 °C in next 30 years. Gas hydrates are ice-like structures that are capable to store metric tons of CO2 in subsea conditions. The storage of CO2 into gas hydrates is a front runner among other sequestration as reemission of CO2 into the environment is difficult. In this current study, hydrate formation kinetics has been tested in high-pressure continuous stirred tank reactor (CSTR), mimicking actual subsea temperature and pressure conditions. Our research contributes to the understanding of the behavior of CO2 hydrates formation kinetics in seawater and advances our ability to model and predict the formation and dissociation. The experiment was conducted in a 1400 ml high-pressure continuous stirred tank reactor with experimental pressure and temperature condition of 4.58 MPa and 274.15 K. Our experimental studies demonstrates that salinity has an inhibitory effect on CO2 hydrate formation kinetics. The kinetics of CO2 hydrate formation were examined in seawater conditions and pure water and our findings demonstrate that several variables, including pressure, temperature, salinity, and stirring rate, have an impact on the rate of CO2 hydrate formation. These findings can inform the design and improvement of hydrate-based CCS technologies by offering useful insights into the mechanism of CO2 sequestration in the form of hydrates in oceans.