Prediction of CO2 solubility in aqueous deep eutectic solvent using Aspen modelling approach

Current work focuses on the modelling of experimentally measured carbon dioxide (CO2) solubility data in aqueous deep eutectic solvent using (1EAHC:9DETA, 30%v) at various temperature and pressure conditions. The Peng-Robinson (PR) equation of state was used to characterize the vapor phase while UNIFAC group contribution model was used to model the non-ideality of the liquid phase. Aspen Plus was employed to model the phase equilibria of the measured experimental data. The predicted CO2 solubility results were in good agreement with the measured values with R² of 0.9937. Key thermodynamic properties were calculated, including Henry’s constant, enthalpy and entropy of absorption along with excess Gibb’s free energy. The negative value of enthalpy of absorption (ΔH_abs = − 8.52 kJ/mol) indicated that the process was exothermic and there was strong interaction between the DES and CO2. Comparative analysis with aqueous 30% MEA revealed that the studied DES required lower regeneration energy, demonstrating its potential as an energy-efficient alternative for CO₂ capture applications. The successful implementation of the PR-UNIFAC model framework provides a robust tool for predicting CO₂ solubility in novel DES systems.