This study provides comprehensive insights into the growth kinetics and gas storage performance of methane and CO₂ hydrates formed from cyclopentane (CP) hydrate seeds in the presence of various kinetic promoters under static conditions. By introducing preconstructed hydrate seeds and surface-active promoters such as sodium dodecyl sulfate (SDS) and L-methionine, we investigated their synergistic or inhibitive effects on hydrate formation behavior at moderate pressures and temperatures. In methane hydrate systems, SDS and CP hydrate seeds exhibited a strong synergistic effect in enhancing heterogeneous nucleation and initial gas uptake rates, although L-methionine showed limited enhancement due to its minimal effect on reducing interfacial tension, but resulted in improved overall methane storage by promoting water-to-hydrate conversion. For CO₂ hydrate systems, SDS significantly inhibited sI CO₂ hydrate formation due to unfavorable interactions between its alkyl chains and CO₂, as supported by molecular dynamics simulations. Conversely, moderate hydrophobic amino acids, particularly L-methionine, substantially enhanced CO₂ hydrate formation kinetics and storage capacity, both in sI CO2 and sII CP-CO₂ systems, by enabling co-encapsulation of CO₂ and CP molecules. These findings provide valuable guidelines for selecting appropriate kinetic promoters and hydrate seeds, contributing to the optimization of hydrate-based methane storage and CO₂ capture technologies under environmentally benign, energy-efficient conditions.
