Modeling and experiments of equilibrium solubility of carbon dioxide in aqueous N-(2-hydroxyethyl) pyrrolidine solution

In this work, the equilibrium CO₂ solubilities of the aqueous N-(2-hydroxyethyl) pyrrolidine (N-(2-HE) PRLD) at different concentrations (1.0 mol/L–5.0 mol/L) were measured at different temperatures (298 K–333 K) and pressures (8 kPa–101 kPa), using a vapor–liquid equilibrium apparatus. Four semi-empirical thermodynamic models (C_f model, Kent–Eisenberg model, Hu–Chakma model and Li–Shen model) were used to correlate and predict the CO₂ solubility data of the N-(2-HE) PRLD-CO₂–H₂O system. The results showed that the Hu–Chakma model, which is one of the models that incorporates the effect of amine concentration and CO₂ loading, and accounted for nonideality caused by higher temperature, species concentrations and CO₂ loadings, was best able to predict results that are in agreement with the experimental vapor–liquid equilibrium measurements in this work.