Modeling and optimization of ionic liquid-based carbon capture process using a thin-film unit

• Published in: Computers & chemical engineering 2021-12, Vol.155, p.107522, Article 107522
• Main Authors: Seo, Kyeongjun, Chen, Zhichao, Edgar, Thomas F., Brennecke, Joan F., Stadtherr, Mark A., Baldea, Michael
• Format: Article
• Language: English
• Subjects: Flowsheet optimization; Ionic-liquids; Post-combustion carbon capture; Pseudo-transient modeling; Thermal degradation; Thin-film unit
• ISSN: 0098-1354; 1873-4375
• DOI: 10.1016/j.compchemeng.2021.107522

•An advanced carbon capture system based on ionic liquid solvent is introduced.•Solvent regeneration using a thin-film unit under vacuum is proposed.•Regeneration temperature and associated solvent residence time are reduced.•Detailed thermodynamics and rate-based packed column models are implemented.•Cost related to solvent degradation is reduced compared to the conventional design. Post-combustion CO2 capture is an effective solution for reducing CO2 emissions. Ionic liquids (ILs) have been proposed as a promising class of absorbents for CO2 capture due to their superior physicochemical properties. As ILs are expected to be, at least initially, costlier than conventional amine solvents, the economic impact of thermal degradation can be more significant for IL-based processes than for conventional systems. In this work, we introduce an advanced IL-based carbon capture process design using a thin-film unit under vacuum to regenerate the solvent. Using this new configuration, the regeneration system can operate at lower temperatures and the solvent residence time can be significantly reduced, minimizing IL absorbent losses due to thermal degradation. We conduct a detailed, rate-based analysis of the impact of thermal degradation kinetics on the economic performance of the proposed process. A comparison to a conventional flowsheet configuration is also presented.