Influence of sodium chloride on the melting of ice and crystallization and dissociation of CCl3F hydrate in water in oil emulsion

Trichlorofluoromethane (CCl 3 F) and water form clathrate hydrate which melts at 8.5 °C under atmospheric pressure. By DSC and X rays analysis we could distinguish between hydrate and ice formed in emulsion containing NaCl and show that quantity of hydrate formed and its dissociation temperature are dependent on solution concentration. The equilibrium curve hydrate-NaCl solution is displaced towards higher temperatures with respect to corresponding ice curve. Consequently solid–liquid equilibrium can not be established in presence of both solids. Growth of hydrate crystals at the expense of ice was evidenced. Role of salt in hydrate growth and ice melting is examined.