Mechanism Analysis of β-Cyclodextrin’s Influence on the Formation of Carbon Dioxide Hydrates in Oil–Water Systems

Carbon capture technologies based on hydrates offer promising avenues for efficient CO2 sequestration. This study sequentially investigated the effects of stirring rate on the formation kinetics and morphology of CO2 hydrates in pure water systems, β-cyclodextrin (β-CD) stirring systems, and relative multiphase systems of β-CD with n-decane (C10). The experimental results indicate that, under stirring conditions, β-CD effectively promotes the formation of carbon dioxide hydrates. At a concentration of 2000 ppm, CO2 consumption reaches 129% of that in pure water, and the induction time is shortened to 22.5%. In the β-CD-C10 mixed system, the addition of 2000 ppm β-CD significantly enhanced gas uptake at all C10 concentrations. At 10 wt % C10, gas uptake increased by 145% compared to the pure C10 system, shifting from inhibition to promotion. The composite system exhibited optimal promotion at a C10 concentration of 5 wt %, outperforming both pure C10 and β-CD systems.