Density calculations of aqueous amine solutions using an excess Gibbs based model

Accurate representation of the physical properties of a solvent is essential for design and simulation of processes. Density and viscosity, for instance, have an important role in modelling and designing absorption and desorption towers. In the present work, a model to accurately calculate the density of aqueous amine solutions used in CO2 capture was developed as a function of temperature and composition. The model is based on excess Gibbs energy functions, and in this work the functional form of the non-random two-liquid (NRTL) model was used. The model is able to accurately represent the density of the tested systems with deviations below 0.2% for most cases. The pure component density was calculated using the modified Rackett equation with the parameter ZRA as a function of the temperature and pressure of the system. The calculated deviation (AARD) for pure component density was below 0.09%