E. Zhao et S. Saha, APPLICATIONS OF COMPLEX-DOMAIN IN VAPOR-LIQUID-EQUILIBRIUM CALCULATIONS USING A CUBIC EQUATION OF STATE, Industrial & engineering chemistry research, 37(5), 1998, pp. 1625-1633
A new method is proposed to identify the spurious root (density or com
pressibility) in a cubic equation of state when it is used for phase p
roperty calculations and also to evaluate the pseudo root for an unfea
sible phase specification based on a heuristic approach. The variation
of real and real part of the complex roots with pressure for a cubic
equation of state at constant temperature and composition is taken int
o consideration in the development. A complete set of analytical expre
ssions is developed for the implementation of the method. The validity
of the method is demonstrated through examples. The proposed method i
s simple and easy to use. Moreover, the computational load involved in
the implementation of the proposed method is minimal because no itera
tive strategy is required.