Simulation and analysis of CO2 capture process with aqueous monoethanolamine solution

An improved rate-based model of the typical CO2 capture process by aqueous MonoEthanolAmine (MEA) solution is built within Aspen Plus V8.0 software in this study. The improved model is built on the basis of an example model coming along with Aspen Plus V8.0, and thermodynamic model of ENRTL-RK is adopted. Improvements include the washing section of the absorption column is strictly modelled by a separate column, and the error on mass balance of MEA is greatly reduced. The new model is validated by the recently published pilot-scale experimental results of the absorption of CO2 by MEA solution, in which both absorption and desorption columns are equipped with the structured packing Sulzer Mellapak 250.Y™. It predicts the experimental profiles of the temperature and the concentration of CO2 in the liquid phase with an accuracy of ±4%, and obviously much better than recently reported model with an accuracy of ±8%. Important insights have been obtained on the function of washing sections on the top of both absorber and desorption column, the factors to determine the flowrates of make-up water and recycle water around the washing section of the absorber are first analyzed.