Screening Tool for Water-Free and Water-Lean Amine-based Solvents for CO₂ Capture

Owing to the high regeneration energy of conventional aqueous amines, water-free and water-lean solvents have emerged as potential alternatives for absorption CO2 capture processes. Given the wide array of possible solvents and required properties, rapid and reliable screening tools are required. Hence, this contribution is focused on demonstrating the capabilities of the soft-SAFT equation of state as a reliable thermodynamic model for the accurate representation of CO2 chemisorption in these novel solvents. Calculations of CO2 cyclic capacity and total energy of regeneration allow evaluating the performance of these solvents relative to their aqueous counterpart as a first screening tool. Results indicate that at the same conditions, transition the MEA-based solvent from aqueous, to water-lean, and finally to non-aqueous, lead to decreased cyclic capacity but also lower energy of regeneration.