Effect of fiber variation on the performance of countercurrent hollow fiber gas separation modules

A theoretical and experimental study of the effects of variable fiber properties on countercurrent hollow fiber gas separation module performance is presented. Variations in ID, slow gas permeance, and selectivity are considered. Variability in any of these properties is detrimental to performance. The drop in performance increases as either property variation or product purity increase, but permeate mixing can improve performance. Fibers with higher permeation to feed rate ratios may stop producing a retentate product and may consume product from other fibers. The theory agrees well with experiments for the production of nitrogen from air.