Modified UNIFAC (Dortmund)

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The following modifications are made to the Original UNIFAC model[1]:

Combinatorial part of liquid activity coefficient:

 ln \gamma^C_i = 1 - V'_i + ln V'_i - 5 q_i (1 - \frac{V_i}{F_i} + ln \frac{V_i}{F_i})

Volume/mole fraction ratio:

 V_i' = \frac{r_i^{3/4}}{\sum_j r_j^{3/4} x_j}

Main group interaction parameter matrix:

 \Psi_{nm} = exp(- { {a_{nm} + b_{nm} T + c_{nm} T^2} \over {T} })

References

  1. Gmehling, Kolbe, Kleiber, Rarey; Chemical Thermodynamics for Process Simulation; February 2012; Wiley ISBN 9783527312771

See also