Tailor‐made asymmetric PVDF hollow fibers for soluble gas removal

Tailor‐made polyvinylidene fluoride (PVDF) asymmetric hollow‐fiber membranes and their membrane modules were employed for soluble gas removal, such as H 2 S from waste gas streams. This study focused on the techniques of fabricating and characterizing the PVDF asymmetric hollow‐fiber membranes and their membrane modules for removal of H 2 S using an aqueous solution containing 10% NaOH. A laminar parabolic velocity profile was used to characterize the flow of the H 2 S gas mixture in the hollow‐fiber lumen. Effects of operating conditions and the morphological structures of the membranes on the membrane´s coefficient, k AM , were examined both theoretically and experimentally. The capabilities of the hollow‐fiber membranes developed for removal of H 2 S from waste gas streams were evaluated and compared with conventional symmetric hydrophobic hollow‐fiber membranes, such as polypropylene. An analysis of H 2 S transfer across the more developed PVDF membranes reveals that the membrane´s coefficient, k AM , evaluated from its structure parameters, such as the effective surface porosity and mean radius, agreed well with the experimental data obtained from absorption experiments.