Thermally rearranged (TR) polybenzoxazole hollow fiber membranes for CO2 capture

Thermally rearranged polybenzoxazole (TR-PBO) hollow fiber membranes were prepared using a non-solvent induced phase separation method intended to apply for CO2 separation from post-combustion flue gas. Asymmetric hollow fiber membranes were spun from a hydroxyl poly(amic acid) (HPAAc) precursor and subsequently converted to TR-PBO hollow fiber membranes after thermal treatment above 400 °C. The skin structure and porous substructure in TR-PBO hollow fiber membranes were maintained even after thermal treatment at above glass transition temperature (Tg) of precursor polymers. To fabricate defect-free hollow fiber membranes, the effects of dope composition and thermal rearrangement conditions were investigated. Gas permeation properties of TR-PBO hollow fiber membranes measured by constant pressure method with small laboratory scale test module revealed a high CO2 permeance (1940 GPU) with a CO2/N2 selectivity of 13.