Hydrate Technologies for CO2 Capture and Sequestration: Status and Perspectives

CO 2 capture and sequestration based on hydrate technology are considered supplementary approaches for reducing carbon emissions and mitigating the greenhouse effect. Direct CO 2 hydrate formation and CH 4 gas substitution in natural gas hydrates are two of the main methods used for the sequestration of CO 2 in hydrates. In this Review, we introduce the crystal structures of CO 2 hydrates and CO 2 –mixed gas hydrates and summarize the interactions between the CO 2 molecules and clathrate hydrate/H 2 O frames. In particular, we focus on the role of diffraction techniques in analyzing hydrate structures. The kinetic and thermodynamic properties then are introduced from micro/macro perspectives. Furthermore, the replacement of natural gas with CO 2 /CO 2 –mixed gas is discussed comprehensively in terms of intermolecular interactions, influencing factors, and displacement efficiency. Based on the analysis of related costs, risks, and policies, the economics of CO 2 capture and sequestration based on hydrate technology are explained. Moreover, the difficulties and challenges at this stage and the directions for future research are described. Finally, we investigate the status of recent research related to CO 2 capture and sequestration based on hydrate technology, revealing its importance in carbon emission reduction.