A consistent thermodynamic model for Solid Liquid Equilibrium (SLE) and Vapor Liquid Equilibrium (VLE) in aqueous amine solutions

Two thermodynamic models (NRTL/UNIQUAC) were tested to model the SLE and VLE of the aqueous piperazine system. The reported 6 species in solid and liquid phases were represented successfully together with the estimated standard enthalpies and Gibbs energy of formation. The earlier reported experimental data for different SLE and VLE were found to be very useful for this work. The models consistently represent the experimental data. However, efforts are still needed to improve the model and a direct measurement of the solution heat capacity will reduce the number of fitted parameters. (C) 2014 The Authors. Published by Elsevier Ltd.