VLE of CO2 in aqueous sodium glycinate solution – New data and modeling using Kent–Eisenberg model

• New VLE data is generated for CO2 absorption in aqueous sodium glycinate (SG).
• The VLE is modeled using Kent–Eisenberg model.
• Amine deprotonation constant and carbamate hydrolysis constant are determined.
• These constants are function of temperature and initial aqueous SG concentration.
• Physical properties, e.g., viscosity and density of the solvent are measured.

Vapor–liquid equilibrium (VLE) of CO2 in aqueous sodium glycinate solution (SG) is studied in this work. Equilibrium solubility data is measured experimentally in 5–25 mass% aqueous sodium glycinate solution at 313.15, 323.15 and 333.15 K, over the CO2 partial pressure range of 2–600 kPa. Density and viscosity of aqueous sodium glycinate are also measured at same temperature range. From the experimental results it is seen that aqueous solution of SG has good CO2 loading (mole of CO2 absorbed per mole of amine) potential. Experimental VLE data is then correlated using the Kent–Eisenberg model and carbamate hydrolysis equilibrium constant and amine deprotonation equilibrium constant are regressed. Average absolute deviation between experimental and model predicted results is found to be 7.13%.