Vapor-liquid equilibrium (VLE) of CO2 in aqueous solutions of benzylamine: New data and modeling using ENRTL-equation

In this work, new experimental data of carbon dioxide (CO2) solubility in aqueous benzylamine (BZA) solutions were generated at 313.15 K, 323.15 K, 333.15 K and 343.15 K, with the BZA concentrations of 5, 10, 20, 30 mass% and pressure up to 190 kPa. A rigorous thermodynamically consistent model based on Electrolyte Non-Random Two-Liquid (ENRTL) theory has been developed to correlate and predict the vapor liquid equilibrium behavior of CO2 in aqueous BZA. The model predicted CO2 solubility is in good agreement with experimental data showing 19% average absolute deviation (AAD). The model is also utilized to estimate equilibrium liquid phase speciation; pH of the CO2 loaded aqueous BZA solutions and heat of CO2 absorption (∼80 kJ/mol).