Modelling the precipitating non-aqueous CO2 capture system AMP-NMP, using the unsymmetric electrolyte NRTL.

• Modelling of a non-aqueous amine solvent for CO 2 capture. • Thermodynamic parameters, including precipitation equilibrium, were regressed. • Unsymmetric electrolyte NRTL property method was used. • The model agrees qualitatively with experimental data. A thermodynamic property model for the non-aqueous precipitating CO 2 capture system 2-amino-2-methyl-1-propanol (AMP) in N-methyl-2-pyrrolidone (NMP) has been developed. The binary NRTL interaction parameters, electrolyte pair parameters, and equilibrium constant for the precipitation reaction were estimated from experimental data using the unsymmetrical electrolyte NRTL property method (ENRTL-RK) in ASPEN Plus^®. The Gibbs energy and the enthalpy of formation of pure solid were calculated from the regressed equilibrium constant. A simple flash tank simulation was run based on the property model developed to compare experimental data with the predictions of the model. The property model was able to qualitatively predict the behavior of the solubility curves and the heat of absorption for the system. This makes it possible to develop a rigorous plant model for the AMP in NMP system, which could be used to further assess and explore potential energy savings when using this amine solvent for CO 2 capture. [ABSTRACT FROM AUTHOR]