Unifac Model for Prediction of Excess Properties for {Water-Amine} Systems

AfficheIndustrial processes for carbon dioxide capture were developed for the treatment of natural gas. They are based on the dissolution of CO2 in aqueous solution of amine. The mechanism is a combination of acido basic reaction and physical dissolution. The thermodynamic representation of the gas-liquid equilibria in {CO2-water-amine} systems is complex [1] as it contains both molecules and ions. To take in account non ideality some interaction parameters can be obtained from binary system such as {water + amine}. However experimental data are scarce except in the case of monoethanolamine (MEA) [2]. In this work the Unifac model [3] was tested for prediction of excess properties of water-amine systems. Some interactions coefficients in the original model were modified using excess enthalpy data of water-MEA. The Unifac model with the new coefficients was tested for prediction of excess properties of different alkanolamines [4] for which experimental data are available in literature