<p>Hydrate-based carbon capture (HBCC) offers high CO₂ selectivity, low regeneration energy, and operation under mild temperature conditions, making it a promising alternative to conventional solvent-based methods. However, large-scale implementation is hindered by the high pressures required for hydrate formation from fuel gas mixtures (FGMs), leading to increased energy consumption and operational costs. Reducing the equilibrium pressure through effective thermodynamic promotion is therefore essential to improve process efficiency. Many existing promoters suffer from drawbacks such as environmental toxicity, poor recyclability, or adverse impacts on hydrate kinetics, highlighting the need for safe, recyclable liquid phase promoters that enhance hydrate stability.</p><p>This study investigates the thermodynamic promotion effect of 1,3-dioxolane (DIOX) on FGM hydrates using high-pressure micro-differential scanning calorimetry (µDSC). Phase equilibrium measurements were performed at DIOX concentrations of 1.0, 3.0, and 5.56&#xa0;mol%. The addition of DIOX shifted the hydrate equilibrium boundary toward lower pressures and higher temperatures, with the most pronounced shift observed at 5.56&#xa0;mol%, corresponding to the stoichiometric composition for structure II hydrates. µDSC analysis revealed clear pressure- and concentration-dependent increases in dissociation temperature. Clausius–Clapeyron analysis of the equilibrium data indicated increasing dissociation enthalpies with higher DIOX concentrations, reflecting enhanced lattice stability. These results demonstrate that DIOX is an effective and environmentally benign thermodynamic promoter capable of lowering operating pressures and reducing energy penalties in HBCC systems, thereby improving the feasibility of large-scale carbon capture applications.</p>