Porous media Eulerian computational fluid dynamics (CFD) model of amine absorber with structured-packing for CO2 removal

Abstract

A gas–liquid Eulerian porous media computational fluid dynamics (CFD) model was developed for an absorber to remove CO2 from natural gas by mono-ethanol-amine (MEA). The three dimensional geometry of the amine absorber packed with nine elements of Mellapak 500.X (M500X) was constructed for the CFD domain. The momentum conservation equation included the porous resistance, gas–liquid momentum exchange and liquid dispersion to replace the structured-packing by the porous media model. The mass conservation equation involved the mass transfer of CO2 gas into the MEA solution and one chemical reaction. The mesh independent test was performed on coarse, medium and fine meshes and the medium mesh (37,400 cells) was selected for further investigation. Parameters of the CFD model were adjusted to fit experimental data (wet pressure drop, liquid holdup, and CO2 mole fraction along the column height) measured in a CO2-MEA system on M500X. This study demonstrated that the porous media CFD model can treat both hydrodynamics and CO2 removal in the amine absorber with structured-packing.