Polysulfone hollow fiber membrane system for CO2/CH4 separation: Influence membrane module configuration on the separation performance

Abstract

Separation of CO2/CH4 using polysulfone hollow fiber membrane system using cascade and series arrangements was studied. The membranes used were fabricated using 33%wt of polysulfone polymer. Gas permeation properties (pressure-normalized flux and selectivity) were evaluated using pure carbon dioxide and methane as test gases. Results showed that single-stage gas permeation system in cascade arrangement with two-stage of gas permeation system produced the highest CO2/CH4 selectivity especially tested at low feed pressure range. Effect of stage cut on feed pressure showed an increasing trend with increasing of CO2 and CH4 feed pressure in both configurations. This is due to the increase of the permeation driving force, which causes the passage of larger amounts of more permeable gas through the membrane. On the other hand, effect of stage cut on pressure-normalized flux exhibited a constant trend plots for both gases and configurations. This study showed that, cascade configuration exhibited a smaller stage cut values than series configuration. Hence, cascade configuration produced higher purity of CO2 in the permeate stream. The results of this work served as a mean in determining the most suitable module configuration to be used for gas separation processes.