Mass transfer in a small scale post-combustion flue gas absorber, experiment and modelling

P.J.G. Huttenhuis, E.P. van Elk, G.F. Versteeg

Abstract

Carbon dioxide can be removed from flue gas streams with aqueous solutions of alkanolamines. In the absorber carbon dioxide is contacted with the solvent and due to several chemical reactions the carbon dioxide is converted into ionic species. These species are non-volatile and remain in the liquid phase until the carbon dioxide is released in the stripper (by adding heat). For the design of gas treating processes a sound fundamental process model is required in which all relevant mass transfer aspects, thermodynamics and kinetics are incorporated. However, the quality of a process model should always be determined by the validation with experimental data. In this study a rate-based model of a flue gas absorber is compared quantitatively with experimental data derived from a continuous absorber – stripper pilot plant which was operated at typical post-combustion flue gas conditions.

Keywords: absorption; mass transfer; alkanolamine; post-combustion CO2 capture; rate-based