Euler–Euler CFD Modeling of Reactive CO2 Capture in Blended Amines: Benchmark Studies on DEEA+MEA Absorption and MDEA+Pz Desorption

Abstract In the amine-based absorption process, primary/secondary amines such as MEA (monoethanolamine) and Pz (piperazine) exhibit several limitations, such as low absorption capacity and high regeneration energy, whereas tertiary amines such as MDEA (methyl diethanolamine) and DEEA (diethylethanolamine) exhibit higher absorption capacity and lower regeneration energy. To take into account the advantages of individual amines, primary/secondary amines are mixed with tertiary amines to form blended amines. Much research work has been done on CFD modeling of the amine-based absorption process using a single amine, especially MEA. The present work is focused on developing an Euler–Euler CFD model for the CO2 absorption and desorption process in blended amines. To take into account the mass transfer between phases during the reactions, custom mass transfer models are developed in OpenFOAM V8 based on Sh = f(Re, Sc). To take into account the packing inside the column, a porous media approach has been used. In the absorption process of CO2 in the blended amine DEEA + MEA, several parameters, such as the effect of CO2 partial pressure and gas flow rate on the unit volume absorption rate, have been studied. Further studies have been done to study the effect of mass transfer coefficient and temperature on the CO2 desorption process in the blended amine MDEA + Pz. The simulation results obtained from the developed model agree well with the experimental results given in the literature.