Preparation and Characterization of Composite Hollow Fiber Membrane Using PEI and PEO Containing Block Copolymers for SO2 Separation

Combustion of sulfur containing fuels, such as coal, in power plant is the major emission source of sulfur dioxide (SO₂). In this study, hollow fiber membrane separation process applied for the removal of SO₂ in the mixture gas. Dry-wet phase inversion method was used to fabricate the hollow fiber membranes. Polyetherimide (PEI) hollow fiber membrane was manufactured by dry/wet phase inversion method followed by the post-treated with methanol was performed to improve the flux [1]. Hollow fiber membrane was coated with PEO containing block copolymers which has high selectivity for polar gas/non-polar gas separation, since PEO containing block copolymers have an high solubility for polar components such as SO₂, CO₂ [2].

  Produced membrane typically has an asymmetric structure; a dense top layer supported by porous, sponge and finger-like substructure. Single gas permeance of SO₂ and selectivity of SO₂/CO₂ were 2,200~3,658 GPU, 68~105, respectively. Single gas permeance and selectivity were increased with the increase of pressure difference, but N₂ permeance remains constant. SO₂ removal efficiency was increased from 36.8% to 82.5% according to stage cut of 0.1 to 0.5, respectively for the mixture gas of 200ppm SO_2, 12% CO₂ and N₂ balanced at 1.8 kg_f/cm² of operating pressure.

Reference

[1] Hyung-Keun Lee, Hang-Dae Jo, Won-Kil CHoi, Hyun-Hee Park, Chun-Won Lim, Yong-Taek Lee, Absorption of SO₂ in hollow fiber membrane contactors using various aqueous absorbents, Desalination, 200 (2006) 604-605.

[2] Anja. Car, Chrtomir. Stropnik, Wilfredo Yave, Klaus-V.Peinemann, PEG modified poly (amide-b-ethylene oxide) membranes for CO₂ separation, J. Membr. Sci., 307 (2008) 88-95.