The Gibbs Free Energy Method

This section is based on Ballard s (2002) extension of the ground-breaking work in Bishnoi s group by Gupta (1990). To calculate thermodynamic equilibrium for a closed system, three fundamental conditions must be met  

Equality of chemical potential of a component in each phase, 

Regressed Kihara Potential Parameters ( a as in Original Reference) 

That is, if the amount of phases present at the solution is not known a priori, the Gibbs energy must be used to determine what phases are present. 

Implementation of conditions (1) to (3) is done following a similar procedure as that of a two-phase system (Rachford and Rice, 1952). For a system with C components and n possible phases, satisfying a simple mass balance for each component in each phase results in the following objective function  

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