Improving the Efficiency of a Chilled Ammonia CO2 Capture Plant Through Solid Formation: A Thermodynamic Analysis

Post-combustion chemical absorption is regarded as the state-of-the-art commercially-available CO2 capture process. The adoption of aqueous ammonia as solvent, leading to the so-called Chilled Ammonia capture Process (CAP), has long been considered one of the most promising alternatives to amine-based for post-combustion carbon capture. This work investigates the development of a second generation CAP where the capture efficiency is improved by making use of a crystallizer to form solids in the process. The reference standard CAP and the advanced crystallizer-based CAP are simulated in Aspen using the Extended UNIQUAC thermodynamic model. The two CAP solutions are compared in term of the different energy penalties introduced applying the capture process to a conventional Ultra Super Critical (USC) power plant. Thanks to the solid formation, the CAP with the crystallizer features a lower energy penalization with a decrease of about 10% compared to the total penalty of the standard CAP.ISSN:1876-610