NRTL

The Non-Random-Two-Liquid model presented by Renon and Prausnitz. This model uses local compositions to represent the excess Gibbs energy.

\[G^E = nRT \cdot \sum_i x_i \frac{\sum_j x_j \tau_{ji} G_{ji}}{\sum_j x_j G_{ji}}\]

with:

\[\tau_{ij} = A_{ij} + \frac{B_{ij}}{T}\]

\[G_{ij} = exp(-C\tau_{ij})\]

Where \(A_{ij}, B_{ij}, \text{ and } C\) are fittable parameters.

[1]:

import yaeos


aij = [
    [0.0, -0.801, -0.351],
    [-0.523, 0.0, 0.214],
    [0.127, 0.211, 0.0],
]

bij = [
    [0.0, -586.1, 246.2],
    [301.2, 0.0, -104.2],
    [150.23, -114.78, 0.0],
]

cij = [
    [0.0, 0.3, 0.3],
    [0.3, 0.0, 0.3],
    [0.3, 0.3, 0.0],
]

model = yaeos.NRTL(aij, bij, cij)

n = [2.0, 2.0, 8.0] # number of moles [mol]
T = 298.15          # Temperature [K]

model.ln_gamma(n, T)

[1]:

array([ 0.08590952, -0.94469266,  0.1460286 ])