| 초록 |
Cyclopentane (CP) forms gas hydrate with water under atmospheric pressure. CP can function as a thermodynamic promoter for gas hydrates, which can reduce hydrate equilibrium pressure at a given temperature. Accordingly, CP hydrate can be used for various potential applications of desalination and gas storage. However, the thermodynamic stability and guest inclusion behavior of CP + guest gas systems were not clearly revealed. In this study, four-phase (hydrate-liquid water-liquid CP-vapor) equilibria of the CP + guest gas (CH4, CO2, and N2) + water mixtures were measured to determine the stability conditions of the mixed gas hydrate systems. The quintuple point was also investigated for the CP + CO2 hydrate in the high pressure region. The accurate structure and guest distributions of CP hydrates with guest molecules were analyzed through 13C NMR and Raman spectroscopy. The hydration number and dissociation enthalpy of CP hydrate were measured using DSC (differential scanning calorimetry). It was found from the experimental results that the CP + guest gas hydrates form sII hydrates and CP molecules occupy large 51264 cages of sII hydrate. |
