Correlation and prediction of thermodynamic properties of dilute solutes in water up to high T and P. II. Normal fluids CO2, C2H4, C2H6, C3H8, n-C4H10, i-C4H10, functional groups CH3 and CH2

Abstract

Fugacity coefficients of dilute aqueous solutions of six species belonging to normal fluids (CO2, C2H4, C2H6, C3H8, n-C4H10, i-C4H10) as well as functional groups CH3 and CH2 have been evaluated from ambient conditions (298 K, 0.1 MPa) to high temperatures (up to 2000 K) and water densities (up to 1500 kg m−3). The basis of the approach is a correlation developed for the function, A12∞=V2∞/κTRT, that includes known constraints: second virial coefficients at low water densities, hard sphere behavior at high water densities, near-critical principles, and corresponding-states relations. A comparison with literature data at subcritical (Henry's and vapor-liquid distribution constants) and supercritical temperatures (fugacity coefficients) is made. For aqueous CO2, the agreement with literature data is generally satisfactory. It is shown that for other solutes existing disagreements can be traced mostly to the values of the second cross virial coefficients employed in the literature models, suggesting the room for improvement of existing recommendations.