Activity Coefficient Model: UNIFAC (NIST-KT) for Ternary Mixtures
Note 1: Models for ternary systems are based solely on the combined results for the binary sub-systems. Specific formulations are described in the book by Novak, Matous , and Pick, Liquid-liquid equilibria, which is Volume 4 of the series Studies in Modern Thermodynamics published by Elsevier in 1987 (See ref 31).Note 2: The same model must be used for all binary sub-systems in order to calculate the properties of the ternary.
Note 3: Only vapor-liquid equilibrium (VLE) and liquid-liquid equilibrium (LLE) are considered.
Ψij = exp{-(A + B/T)}. Qtype(k)is the UNIFAC parameter q for structural group k of the appropriate type. Parameters q and r for each component are calculated as the sum of q and r contributions from all structural groups.