Phase Equilibrium for Hydrofluorocarbon R134a Hydrate. Hydrate-Based Desalination of NaCl Salt Solution

Abstract

Experimental dependences (pressure-temperature) of phase equilibrium of hydrofluorocarbon R134a hydrate have been obtained in aqueous solution of the NaCl salt. The measurements were carried out at a salt concentration in water of 3.25 wt. % in the pressure range from 0.5 to 2.5 bar at temperatures varying from −3 to 10°C. In contrast with the pure water system, the presence of salt in the solution had an inhibitory effect. The equilibrium temperature on the equilibrium curve of R134a hydrate at a set pressure decreased by 12–25%, unlike the temperature for the system with pure water. Combined washing process followed by centrifugation decreased the mass concentration of the salt in the solution by 92% compared to the initial salt concentration.