Process Modeling of CO₂Absorption with Monoethanolamine Aqueous Solutions Using Rotating Packed Beds

A first-principle process simulation model is presented for the chemical absorption of carbon dioxide (CO₂) with monoethanolamine (MEA) aqueous solutions using rotating packed beds (RPB). Built on a proven rate-based packed bed absorber model, the RPB model rigorously simulates the phase and chemical equilibria at the vapor-liquid interface, the heat and mass transfer across the gas and liquid films, the fast reactions between MEA and CO₂in the liquid film, and the RPB hydraulics. Estimation of the rate of transfer of mass across the liquid film is central to accurate simulation of the CO₂absorption process with MEA aqueous solutions. We show that the literature lab-scale RPB data for CO₂removal efficiency can be satisfactorily correlated by introducing a correction factor for the effective packing surface area predicted by the Onda correlation. Given the validated RPB model, we further show that, among the gas-phase mass transfer coefficient, the liquid-phase mass transfer coefficient, and the reaction rate constant for the reaction between amine and CO₂, the reaction rate constant is the controlling step with the greatest potential to enhance the CO₂absorption performance in RPB.