Process Modeling of CO2 Absorption with Monoethanolamine Aqueous Solutions Using Rotating Packed Beds

Abstract

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 CO2 in 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 CO2 absorption process with MEA aqueous solutions. We show that the literature lab-scale RPB data for CO2 removal 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 CO2 absorption performance in RPB.