Investigation of mixture stability at given volume, temperature, and number of moles

We derive a criterion for phase stability under constant temperature, moles, and volume using the Helmholtz free energy. Using the volume-based formulation, we develop a numerical algorithm to investigate single-phase stability based on the Newton method. We demonstrate robustness and efficiency of the new method in a number of examples in single-phase stability testing.

► We derive a criterion for phase stability at constant temperature, moles and volume. ► A numerical algorithm to investigate phase stability at constant volume is proposed. ► Several examples of single-phase constant-volume stability testing are presented.