NRTL

Chemical Reactor Design Toolbox Reference Manual

ChemReactorDesign.Basic.Liquid.Functions.NRTL

The activity coefficients for all species in the liquid mixture arc obtained as

\begin{equation*} \gamma_{i} = \exp \left\{ \frac{\sum\limits_{j}^{N} x_{j} \, \tau_{ji} \, G_{ji}}{\sum\limits_{j}^{N} x_{j} \, G_{ji}} + \sum_{j}^{N} \frac{x_{j} \, G_{ij}}{\sum\limits_{k}^{N} x_{k} \, G_{kj}} \left( \tau_{ij} - \frac{\sum\limits_{k}^{N} x_{k} \, \tau_{kj} \, G_{kj}} {\sum\limits_{k}^{N} x_{k} \, G_{kj}} \right) \right\} \end{equation*}

with

\begin{equation*} \tau_{ij} = \frac{A_{ij}}{R \, T} \end{equation*}

and

\begin{equation*} G_{ij} = \exp\left\{ -\alpha_{ij} \, \tau_{ij}\right\} \end{equation*}

Nomenclature

\(A_{ij}\) binary interaction coefficients
\(N\) number of species
\(R\) universal gas constant
\(T\) temperature
\(x_{i}\) mole fraction of species Ai
\(\alpha\) NRTL parameter
\(\gamma_{i}\) activity coefficient of species Ai

Bibliography