Research progress and challenges in hydrate-based carbon dioxide capture applications

Climate change lends urgency to measures towards emission reduction. Carbon capture and storage is a technique that enables separation and storage of CO₂ from gas mixtures before emission. Among various carbon capture methods, hydrate-based carbon capture is recognised as a promising technology due to its high CO₂ storage capacity and low cost. This paper reviews recent research progress of hydrate-based carbon dioxide capture and sequestration, which is expatiated based on three stages. It discusses: (i) the influence of operating conditions on gas–water mass transfer in the mixing stage; (ii) the effects of thermodynamic promoters to tune the phase equilibrium and kinetic promoters to prompt hydrate formation and separation in the hydrate formation and capture stage; (iii) influencing factors of CH₄–CO₂ replacement and long-term CO₂ sequestration in the sequestration stage. Further, research challenges, namely the phase equilibrium in high-pressure regions, low gas uptake and CO₂ gas selectivity, contradictory experimental findings, and overlooked technical issues, are summarised. Suggestions are given for future research directions.