Phase Equilibrium Conditions for Krypton Clathrate Hydrate below the Freezing Point of Water

The dissociation behavior of krypton (Kr) hydrate below the freezing point of water was characterized using optical scanning microscopy (OSM). The dissociation temperature was obtained in the pressure range of (0.10 to 1.42) MPa. The dissociation temperature of Kr hydrate at 0.1 MPa, which was inconsistent in previous reports, was 204.4 K. Using the Clausius−Clapeyron equation, the enthalpy of Kr hydrate dissociation was estimated to be approximately 18.5 kJ·mol−1. This value agreed well with (19.54 ± 0.24) kJ·mol−1, which was obtained from a previously reported calorimetric analysis.