Interfacial tensions of systems comprising water, carbon dioxide and diluent gases at high pressures: Experimental measurements and modelling with SAFT-VR Mie and square-gradient theory

摘要

Experimental interfacial tensions of the systems (H2O + CO2), (H2O + N-2), (H2O +Ar), (H2O + CO2 + N-2) and (H2O + CO2+ Ar) are compared with calculations based on the statistical associating fluid theory for variable range potentials of the Mie form (SAFT-VR Mie) in combination with the square-gradient theory (SGT). Comparisons are made at temperatures from (298 to 473) K and at pressures up to 60 MPa. Experimental data for the systems (H2O + CO2), (H2O + N-2) and (H2O + CO2 + N-2) are taken from the literature. For the (H2O +Ar) and (H2O + CO2 +Ar) systems, we report new experimental interfacial-tension data at temperatures of (298.15-473.15) K and pressures from (2 to 50) MPa, measured by the pendant-drop method. The expanded uncertainties at 95% confidence are 0.05 K for temperature, 70 kPa for pressure, 0.016 x gamma for interfacial tension in the binary (Ar + H2O) system and 0.018 x gamma for interfacial tension in the ternary (CO2 + Ar + H2O) system.