Targeting the control in emissions of post-combustion carbon dioxide capture from large point sources, a simulation approach towards the estimation of important thermodynamic property parameters useful in designing of carbon capture and sequestration technologies is being proposed. In the current work, simulation is carried out for modeling the gas – liquid equilibrium of CO2 in two aqueous mixtures of ionic liquid 1-butyl-3-methyl imidazolium acetate (bmimAc) and amines viz. (bmimAc + 1-(2-aminoethyl) piperazine) (AEP) and (bmimAc + bis (3-aminopropyl) amine) (APA). The experimental CO2 solubilities were taken from our previously published work and is regressed with electrolyte–Non-Random Two Liquid (e-NRTL) model for the liquid phase while Redlich-Kwong (RK) equations of state (EOS) was used to model the gas phase. Various thermodynamic parameters of importance and concentration of species in the mixtures were regressed in the model using Aspen Plus 14.