A high-flux polyimide hollow fiber membrane to minimize footprint and energy penalty for CO2 recovery from flue gas

• Published in: Journal of membrane science Vol. 423-424; pp. 302 - 313
• Main Authors: Lively, Ryan P., Dose, Michelle E., Xu, Liren, Vaughn, Justin T., Johnson, J.R., Thompson, Joshua A., Zhang, Ke, Lydon, Megan E., Lee, Jong-Suk, Liu, Lu, Hu, Zushou, Karvan, Oĝuz, Realff, Matthew J., Koros, William J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2012
• Subjects: adhesion; artificial membranes; carbon dioxide; carbon footprint; CO2 capture; coal; Hollow fiber membranes; humidity; Mixed matrix membranes; permeability; polymers; spinning; System footprint; Zeolitic imidazolate frameworks; Hollow fiber membranes; Zeolitic imidazolate frameworks; CO2 capture; Mixed matrix membranes; System footprint
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2012.08.026

Using a process-guided approach, a new 6FDA-based polyimide — 6FDA–DAM:DABA(4:1) — has been developed in the form of hollow fiber membranes for CO2 recovery from post-combustion flue gas streams. Dense film studies on this polymer reveal a CO2 permeability of 224 Barrers at 40°C at a CO2 feed pressure of 10psia. The dense films exhibit an ideal CO2/N2 permselectivity of 20 at 40°C, which permits their use in a two-step counter-flow/sweep membrane process. Dry-jet, wet-quench, non-solvent-induced phase inversion spinning was used to create defect-free hollow fibers from 6FDA–DAM:DABA(4:1). Membranes with defect-free skin layers, approximately 415nm thick, were obtained with a pure CO2 permeance of 520GPU at 30°C and an ideal CO2/N2 permselectivity of 24. Mixed gas permeation and wet gas permeation are presented for the fibers. The CO2 permeance in the fibers was reduced by approximately a factor of 2 in feeds with 80% humidity. As a proof-of-concept path forward to increase CO2 flux, we incorporated microporous ZIF-8 fillers into 6FDA–DAM:DABA(4:1) dense films. Our 6FDA–DAM:DABA(4:1)/ZIF-8 dense film composites (20wt% ZIF-8) had a CO2 permeability of 550 Barrers and a CO2/N2 selectivity of 19 at 35°C. Good adhesion between the ZIF and the 6FDA–DAM:DABA(4:1) matrix was observed. CO2 capture costs of $27/ton of CO2 using the current, “non-optimized” membrane are estimated using a custom counterflow membrane model. Hollow fiber membrane modules were estimated to have order-of-magnitude reductions in system footprint relative to spiral-wound modules, thereby making them attractive in current space-constrained coal-fired power stations. [Display omitted] ► 6FDA–DAM:DABA(4:1) has a CO2/N2 selectivity of 20 and CO2 permeability of 224 Barrers. ► Defect-free 6FDA–DAM:DABA(4:1) hollow fibers have a pure CO2 permeance of 520GPUs. ► ZIF-8 mixed matrix membrane: good adhesion to polymer, 250% improvement in permeability. ► CO2 capture costs of $27/ton, system footprint is 10x smaller than spiral-wound modules.