Mutual Diffusion Coefficients of Aqueous KCl at High Pressures Measured by the Taylor Dispersion Method

Abstract

Diffusion coefficients of potassium chloride in potassium chloride solutions of molality (0, 1, 2.5, and 4.5) mol·kg–1 were measured at temperatures of (298.15, 323.15, 348.15, 373.15, and 423.15) K and at pressures from (0.1 to 69) MPa using the Taylor dispersion technique. The results have an overall estimated expanded relative uncertainty of 1.6 % with a coverage factor k = 2. When compared with standard reference data for the diffusion coefficient of KCl in KCl solutions at T = 298.15 K and p = 0.l MPa, a relative deviation of 0.5 % is observed. The effect of pressure was found to be very small. A satisfactory multiparameter correlation of all of the data in terms of pressure, temperature, and molality was obtained; this exhibits an absolute average relative deviation of 1.2 % in comparison with our data. The model also provides a good account of the majority of the data available in the literature.