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

Percent removal of CO 2 with feed concentration at varying feed flow-rates. [Display omitted] ► Application of hollow fiber membrane contactor (HFMC) for CO 2 removal from water. ► Mathematical model to explain unsteady state mass transfer of CO 2 in HFMC module. ► Axial and radial diffusion of CO 2 molecules across lumen considered for model. ► Permeation of CO 2 gas molecules considered across lumen wall made of Polypropylene. ► Permeability coefficient obtained for CO 2 transport across polypropylene membrane. In this study, we investigate the application of a hollow fiber membrane contactor operated in the LLE mode for the removal of dissolved CO 2 from water. The membrane contactor consists of hydrophobic polypropylene microporous hollow fibers. Experiments are performed to determine the extent of CO 2 removal from the feed water flowing through the lumens of the hollow fibers. The feed at different concentration levels of dissolved CO 2 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 CO 2 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 CO 2 and study its transport through water and membrane pores. The numerical value of the permeation coefficient obtained for CO 2 in the hollow fiber membrane was found to be in good agreement with the data in literature.