(184a) Thermodynamic Modeling for CO2 Absorption in Aqueous Potassium Carbonate Solution with Electrolyte NRTL Model

Potassium carbonate has recently gained attention and is considered favorable for CO₂ removal due to numerous reasons such as low economic costs and energy consumption, low volatilization and degradation and less environmental impacts compared to amine solutions. Therefore, we develop a comprehensive thermodynamic model for the K₂CO₃ – H₂O – CO₂ system using the Electrolyte Nonrandom Two-liquid (eNRTL) activity coefficient model in conjunction with PC-SAFT equation of state. Vapor-liquid equilibrium (VLE), heat capacity, excess enthalpy, mean ionic activity coefficient and osmotic coefficient data are used to determine eNRTL temperature dependent binary interaction parameters for both K₂CO₃ – H₂O binary and K₂CO₃ – H₂O – CO₂ ternary systems. The model accurately represents all the thermodynamic properties and covers a wide temperature range from 273.15 to 473.15 K and CO₂ loading from 0 to 1 The model can be merged with other amine models for mixed K₂CO₃ – amine solutions and the model can be used for comparison with other CO₂ capture chemical solutions. The model should be a useful tool in the process modeling, simulation and design of CO₂ capture processes involving hot, concentrated K₂CO₃ solutions at elevated temperatures and pressures.