Prediction of thermodynamics and fluid-phase behaviour of aqueous
solutions of linear, branched, and cyclic amines
Abstract
The SAFT-γ Mie group-contribution equation of state is used to represent
the fluid-phase behaviour of aqueous solutions of a variety of linear,
branched, and cyclic amines. New group interactions are developed in
order to model the mixtures characterised by alkyl primary, secondary,
and tertiary amine groups (NH2, NH, N), cyclic secondary and tertiary
amine groups (cNH, cN), and cyclohexylamine groups (cCHNH, cCHN). The
group-interaction parameters are estimated from appropriate experimental
thermodynamic data for pure amines and selected mixtures. The
fluid-phase behaviour of these mixtures can then be described over broad
ranges of temperature, pressure, and composition. Liquid-liquid
equilibria (LLE) bounded by lower critical solution temperatures (LCSTs)
have been reported experimentally and are reproduced here with SAFT-γ
Mie approach. The main feature of the approach is the ability to
represent accurately the experimental data employed in the parameter
estimation, a to predict the phase equilibria with the same set of
parameters.