Improved Prediction of Saturated and Single-Phase Liquid Densities of Water through Volume-Translated SRK EOS

Abstract

The existing equation of states (EOSs) cannot well reconcile the calculation accuracy and the computational cost for reproducing liquid volumes of water. In this study, we propose a series of improved volume translated Soave-Redlich-Kwong (VT-SRK) EOSs to achieve more accurate volumetric calculation for water with little additional computational cost. The overall average absolute percentage deviation of the saturated liquid molar volume for water yielded by the proposed 4-parameter VT-SRK EOS is 0.26; this calculation error is much lower than the counterpart provided by our previously proposed 3-parameter VT-SRK EOS (1.24) and close to the uncertainty in the pseudo-experimental data reported by NIST (0.1%). After adopting the translated distance function, the proposed 5-parameter VT-SRK EOS provides a more accurate determination for the single-phase liquid volume of water over a wide temperature/pressure range and leads to the crossover of pressure-volume isotherms only at extremely high pressures. The proposed 4-parameter VT-SRK EOS also helps to improve the volumetric prediction for carbon dioxide, while the proposed 5-parameter VT-SRK EOS performs well in improving the density prediction for associating fluids. Moreover, we extend the proposed 5-parameter VT-SRK EOS to mixtures through conventional mixing rules, finding that the VT-SRK EOS provides reliable volume predictions for the aqueous solutions examined in this study.