Impact of thermodynamics and kinetics on the carbon capture performance of the amine-based CO₂ capture system

Solvent-based CO₂ capture is a commonly employed post-combustion technique in processes involving absorber-stripper columns. This study focused on computer simulations with equilibrium- and rate-based modeling of CO₂ capture using the amine solvents 2-amino-2-methyl-1-propanol (AMP), diethanolamine (DEA), and methyl diethanolamine (MDEA) and thermodynamic methods involving electrolyte NRTL models. The objective of this study was to understand the impacts of rate-based modeling, the type of amine, and thermodynamic methods on carbon capture. Within this study, the amine-based CO₂ capture process from coal-power plant flue gas was studied using Aspen Plus modeling. Simulations were also conducted to determine the impact of thermodynamics and kinetics on the CO₂ capture performance of the system. The results were analyzed on the basis of captured CO₂ according to the solvents and models. The equilibrium approach was mostly invalid because of the oversimplified ideal stage assumptions through the column. The lowest carbon capture capacity was obtained with MDEA, while DEA yielded the best results. A sensitivity analysis with rate-based modeling showed the significant impact of the inlet CO₂ composition. The amine-based CO₂ capture process simulation included solution chemistry, electrolyte thermodynamics, rigorous transport property modeling, reaction kinetics, and rate-based multistage simulation, which could be applicable to different solvent systems.