| Name | TDE.UNIQUAC.ActivityCoefficients |
|---|---|
| Comment | Activity coefficients model |
| Variable GEX | Excess Gibbs energy |
| Variable T | Temperature |
| Variable x1 | Mole fraction of component 1 |
| Variable x2 | Mole fraction of component 2 |
| Parameter u12 | Array (0 to nTerms) |
| Parameter u21 | Array (0 to nTerms) |
| Constant r1 | |
| Constant q1 | |
| Constant r2 | |
| Constant q2 | |
| Constant R | Gas constant |
The following expressions define the terms leading to the equation for GEX.
t12 = exp{-u12/(R×T)}
and t21 = exp{-u21/(R×T)}
t1 = (x1×q1)/{x1×q1 + (1 - x1)×q2}
and t2 = {(1 - x1)×q2}/{x1×q1 + (1 - x1)×q2}
f1 = (x1×r1)/{x1×r1 + (1 - x1)×r2} and
f2 = {(1 - x1)×r2}/{x1×r1 + (1 - x1)×r2}
GEX/(R×T) = -q1×x1×ln(t1 + t2×t21) - q2×x2×ln(t2 + t1×t12) + x1×ln(f1/x1) + x2×ln(f2/x2) + 5{q1×x1×ln(t1/f1) + q2×x2×ln(t2/f2)}