Tailor-made asymmetric PVDF hollow fibers for soluble gas removal

Tailor-made polyvinylidene fluoride (PVDF) asymmetric hollow-fiber membrane s and their membrane modules were employed for soluble gas removal, such as H2S from waste gas streams. This study focused on the techniques of fabric ating and characterizing the PVDF asymmetric hollow-fiber membranes and the ir membrane modules for removal of H2S rising an aqueous solution containin g 10% NaOH. A laminar parabolic velocity profile was used to characterize t he flow of the H2S gas mixture in the hollow-fiber lumen. Effects of operat ing conditions and the morphological structures of the membranes on the mem brane's coefficient, k(AM), were examined both theoretically and experiment ally. The capabilities of the hollow-fiber membranes developed for removal of H2S from waste gas streams were evaluated and compared with conventional symmetric hydrophobic hollow-fiber membranes, such as polypropylene. An an alysis of H2S transfer across rite more developed PVDF membranes reveals th at the membrane's coefficient, k(AM), evaluated from its structure paramete rs, such as the effective surface porosity, and mean radius, agreed well wi th the experimental data obtained from absorption experiments.