Development of polyetherimide hollow fiber membrane contactor for chemical CO2 absorption using MEA

In this work, Porous asymmetric polyetherimide (PEI) hollow fiber membranes were fabricated via a phase-inversion method using ethanol (0, 2 and 4 %wt) as non-solvent additive in the polymer dopes. An aqueous solution of 1-methyl-2-pyrrolidone (NMP, >99.5%) was used as bore fluid to prevent forming inner dense skin layer. Water was used as external coagulant. The characterization of fabricated hollow fiber membranes such as, surface porosity, pore size, critical water entry pressure (CEPW) and collapsing pressure were investigated. Also, Scanning Electron Microscopy (FESEM) were used for membrane structure. CO2 absorption performance by Monoethanolamine (MEA>98%) as liquid absorbent in a gas-liquid membrane contactor system were investigated. Results of gas permeation tests showed that CO2 flux increased with an increase in the flow rate of absorbent. Ethanol with 2 wt% provided the membranes with the smaller pore size. Also, Ethanol (2 wt%) in the spinning dope provided the membrane structure with a sublayer with finger-like macro voids, 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 higher CO2 absorption rate than the other PEI hollow fiber membrane. The mast of CO2 absorption rate was (4.28×10-3 s mol/m2s) that achieved at 300 ml/min.

Keywords:

Gas-liquid membrane contactor , CO2 absorption , Hollow fiber membrane , Polyetherimide