Thermodynamic consistency test of high pressure gas-liquid equilibrium data including both phases

摘要

A method to test the thermodynamic consistency of high pressure gas-liquid equilibrium data in binary mixtures which considers data for a single phase has been extended to propose an overall test using the whole set of PTxy data. The method previously proposed by the authors was applied before to situations in which the concentration in the gas phase only was known (a solid dissolved in a high pressure gas) and to situations in which the concentration in the liquid phase only was known (ionic liquid and a high pressure gas). The extension is done here by proposing a combined analysis in which the test is applied to both phases while the modeling is done using bubble pressure calculations as recommended in the literature. Data for water + carbon dioxide mixtures at nine temperatures and for pressures ranging from 100 to 1500 bar and temperatures 383 to 598 K were used. Results indicate that the proposed method is reliable and can be used to check the thermodynamic consistency using all experimental phase equilibrium data available.