Mathematical modeling and numerical simulation of CO2 transport through hollow-fiber membranes

Chemical absorption of carbon dioxide was studied theoretically using hollow-fiber membrane contactors in this work. A 2D mathematical model was developed to study CO2 transport through hollow-fiber membrane contactors. The model considers axial and radial diffusion in the membrane contactor. It also considers convection in the tube and shell side with chemical reaction. The finite element method (FEM) was used to solve the model equations. Modeling predictions were validated with the experimental data obtained from literature for CO2 absorption in amine aqueous solutions as solvent. The modeling predictions were in good agreement with the experimental data for different values of gas and liquid velocities. The liquid solvents considered for this study include aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP) and potassium carbonate (K2CO3). The simulation results indicated that amine aqueous solutions were better than K2CO3 aqueous solution for CO2 absorption. Also simulation results revealed that the removal of CO2 with aqueous solution of MEA was the highest among the amines solvents. The hollow-fiber membrane contactors showed a great potential in the area of CO2 absorption.