Hydrate Technologies for CO₂ Capture and Sequestration: Status and Perspectives

CO₂ capture and sequestration based on hydrate technology are considered supplementary approaches for reducing carbon emissions and mitigating the greenhouse effect. Direct CO₂ hydrate formation and CH₄ gas substitution in natural gas hydrates are two of the main methods used for the sequestration of CO₂ in hydrates. In this Review, we introduce the crystal structures of CO₂ hydrates and CO₂-mixed gas hydrates and summarize the interactions between the CO₂ molecules and clathrate hydrate/H₂O 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 CO₂/CO₂-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 CO₂ 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 CO₂ capture and sequestration based on hydrate technology, revealing its importance in carbon emission reduction.