CO2 removal from a gas stream by membrane contactor

摘要

Gas-liquid membrane contactors were applied to remove carbon dioxide from a gas stream by using an aqueous monoethanolamine (MEA) solution as absorbent. Various modules composed by different numbers of commercial polypropylene capillary membranes were constructed and tested in a laboratory-scale plant fed with a N2-CO2 gas mixture. Attention was especially focused on the CO2 removal efficiency of the different membrane modules when gas flow rate was increased from 5 up to 360 L/h. A mathematical model was developed to simulate the absorption process in order to predict gas removal efficiency from the knowledge of the system physical parameters. The overall membrane mass transfer coefficient k_M was determined and used to compare experimental and predicted removal efficiencies. A good agreement between the developed model and experimental results was found.