Abstract: This paper reports three-phase (ice + hydrate + vapor) equilibrium temperature-pressure conditions in the argon clathrate hydrate forming system at temperatures below the freezing point of water. The thermodynamic model of air clathrate hydrate at temperatures below freezing point of water is required for the analysis of the past climate change using the ice core from the ice sheets at Antarctica and Greenland because the formation of air clathrate hydrate affect the gas composition of air bubbles. The precise phase equilibrium conditions in argon clathrate hydrate forming system should be took into account for the thermodynamic model of air hydrate. The equilibrium conditions were measured by the batch, isochoric procedure. The measured temperature range is from 197.6 K to 241.7 K and the corresponding equilibrium pressure range is from 0.825 MPa to 3.723 MPa. The internal consistency of the measured equilibrium data are investigated by applying the Clausius-Clapeyron equation.

Key words: Clathrate hydrate, phase equilibrium, argon, ice sheet.

Cite: Kotaro Nemoto, Hironori D. Nagashima, Ryo Ohmura, "Formation, Dissociation and Equilibrium of Argon Clathrate Hydrate at Temperatures below Water Freezing Point," International Journal of Materials Science and Engineering, Vol. 7, No. 4, pp. 125-131, December 2019. doi: 10.17706/ijmse.2019.7.4.125-131