Fabrication and characterization of asymmetric polyetherimide hollow fiber membrane contactor for CO2 absorption

Porous asymmetric polyetherimide (PEI) hollow fiber membrane were fabricated via a phase-inversion method using methanol (0, 2 and 4 wt.%) as additive in the dope solution. An aqueous solution of 1-methyl-2-pyrrolidone (90 wt.%) was used as bore fluid to prevent forming inner dense skin layer. The precipitation rate of thepolymer dopes with the different amount of additive was studied using cloud point measurement. The effect of theadditive on the resulting membrane structure, surface porosity, pore size, critical water entry pressure, collapsing pressure and CO2 absorption performance by distilled water in a gas-liquid membrane contactor system were investigated. Cloud point diagrams indicated that the precipitation rate of the polymer dopes increased by increasing additive concentration in the spinning dope. Results of gas permeation tests showed that methanol with 2 wt.%provided the membranes with the larger pore size. The cross-section of the membranes was examined via a scanning electron microscopy. Methanol (2 wt%) in the spinning dope provided the membrane structure with a sublayer with finger-like macrovoids, originating from inner and outer surfaces of the hollow fiber and extending to the middle section of the hollow fiber wall, which resulted in a larger pore size and higher CO2 absorption rate than the other PEI hollow fiber membrane.

کلیدواژه ها:

Polyetherimide ، hollow fiber membrane contactor ، CO2 absorption