SOLUBILITY OF SODIUM-CHLORIDE AND SULFATE IN SUBCRITICAL AND SUPERCRITICAL WATER-VAPOR FROM 450-550-DEGREES-C AND 100-250 BAR

The solubility of sodium chloride in water vapor has been determined a t supercritical temperatures ranging from 450-550-degrees-C and sub- a nd supercritical pressures varying from 100-250 bar. Measured sodium c hloride concentrations ranged from 0.9-101 ppm (by weight). In the exp eriments, water vapor was saturated by continuously flowing it through a tube packed with solid salt. The results for sodium chloride agreed well with other studies which used continuous flow methods. Hydrolysi s of the solid salt was found as a possible explanation for some of th e reported discrepancies in the literature. Experiments with sodium su lfate at 500-degrees-C and 250 bar were also performed. Measured sodiu m sulfate concentrations were around 0.9 ppm, and exhibited unsteady b ehavior. Though only an estimate of Na2SO4 solubility could be obtaine d, this value was over two orders of magnitude lower than that for sod ium chloride at identical conditions.