A new thermodynamic function for phase‐splitting at constant temperature, moles, and volume

We introduce a new thermodynamic function for phase‐split computations at constant temperature, moles, and volume. The new volume function F i introduced in this work is a natural choice under these conditions. Phase equilibrium conditions in terms of the volume functions are derived using the Helmholtz free energy. We present a numerical algorithm to investigate two‐phase equilibrium based on the fixed point iteration and Newton method. We demonstrate usefulness and powerful features of the new thermodynamic function for a number of examples in two‐phase equilibrium calculations. © 2010 American Institute of Chemical Engineers AIChE J, 2011