Thermodynamic analysis using COSMO-RS studies of reversible ionic liquid 3-aminopropyl triethoxysilane blended with amine activators for CO2 absorption

The non-linearity in the CO2 absorption process in the novel aqueous blends of TESA and amine activators AEP and APA is studied through COSMO-RS method. The energy associated with each molecule is estimated using Turbomole. Analysis of the chemical compounds for suitable CO2 absorption is carried out using the trends of sigma potential and sigma surface. Various significant thermodynamic properties (activity coefficient, chemical potential, excess enthalpy and excess Gibbs free energy, infinite dilution activity coefficient) and thermophysical (vapor pressure, density, viscosity) properties of the blends are estimated and compared with the experimental data. The binary interaction parameters for the systems under study using NRTL, WILSON and UNIQUAC 4 models is carried out. All the interaction parameters are functional to temperature and molecular properties of the constituents involved. CO2 solubility of three blended solvents at various concentration and temperatures is reported at (1.0–3.0) bar solute partial pressure. Important chemical reaction parameter pKa of the amine activators in various solvents is estimated at room temperature. An insightful study for the studied systems indicate their possible usage for CO2 absorption and of the many systems studied, the best suitable solvent being aq. (TESA + APA).