The CO2 removal of flue gas using hollow fiber membrane contactor: a comprehensive modeling and new perspectives

In this study, a novel hollow fiber membrane contactor (HFMC) under a non-wet condition was numerically explored by CFD techniques based on the finite element method to capture CO2 from the CH4/CO2 gas mixture. A new design, such as a shell and tube heat exchanger with baffles, was proposed. The MEA, DEA, and TEA, as different amines solutions, were selected as the liquid solvents. A CO2-containing gas mixture and amine solution were passed in the shell side and the tube side of the membrane contactor, respectively. The simulation findings indicated a good agreement with the reported experimental data demonstrating that such a model would evaluate the effects of different parameters during the HFMC system. Specifically, the results showed that the baffles' presence improved the separation efficiency due to the increased residence time on the shell side. The results also indicated that the MEA solution had the highest CO2 absorption. In the new design (shell and tube heat exchanger with baffles), the rising solvent inlet velocity, decreasing gas velocity, and counter-current flow pattern positively affected separation efficiency.