Application of hollow fiber membrane contactor for the removal of carbon dioxide from water under liquid–liquid extraction mode

In this study, we investigate the application of a hollow fiber membrane contactor operated in the LLE mode for the removal of dissolved CO2 from water. The membrane contactor consists of hydrophobic polypropylene microporous hollow fibers. Experiments are performed to determine the extent of CO2 removal from the feed water flowing through the lumens of the hollow fibers. The feed at different concentration levels of dissolved CO2 was extracted using aqueous diethanolamine solution flowing on the shell side of the contactor. A mathematical model was developed, incorporating radial and axial diffusion of solute CO2 in the lumen and its permeation through the pores of the membrane. The governing second order partial differential equation of species balance was numerically solved using the alternate direction implicit technique. The developed mathematical model was used to predict the concentration profiles of CO2 and study its transport through water and membrane pores. The numerical value of the permeation coefficient obtained for CO2 in the hollow fiber membrane was found to be in good agreement with the data in literature.