(697g) Ultrathin MOF-Based Mixed Matrix Hollow Fiber Membranes for Highly Efficient Carbon Capture

Shouliang Yi^1,2*, Patrick Muldoon³, Ali Sekizkardes^1,2, Fangming Xiang¹, Victor Kusuma^1,2, Lingxiang Zhu¹, Nathaniel Rosi³, Kevin.Resnik^1,2, David Hopkinson¹

¹U.S. Department of Energy – National Energy Technology Laboratory, Pittsburgh, PA, 15236

²Leidos Research Support Team, Pittsburgh, PA, 15236

³Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA

The National Energy Technology Laboratory (NETL) is developing the next generation of advanced CO₂ capture concepts. Post-combustion carbon capture from flue gas stream produced by conventional pulverized coal power plants after fuel combustion in air involves the separation of CO₂ (∼10−16%) from nitrogen, the primary constituent of flue gas. Membrane-based processes have been considered as one of the most promising technologies for post-combustion carbon capture due to numerous advantages including lower energy consumption, smaller environmental footprint, and the potential to be installed in an existing power plant as a true bolt-on technology. Polymeric membranes are currently considered the most promising candidate for industrial application due to their additional benefits of being inexpensive and easy to manufacture. However, the performance of polymer membranes are limited by a trade-off upper bound between permeability and selectivity. To overcome the limitations of polymer membranes, mixed matrix membranes (MMMs) have been developed by incorporating inorganic fillers into the polymer matrix. Recently, metal-organic frameworks (MOFs), consisting of metal ions/clusters connected by organic linkers, have received increasing interest as promising candidates for MMMs owing to their diverse functionalities and tunable pore structures. Although a significant improvement in gas separation performance has been observed with the mixed matrix dense/flat sheet membranes, thin-film composite hollow fiber membranes are superior for large-scale industrial application due to their higher packing density, higher gas permeation rate, and lower consumption of selective layer materials.

In this work, we match the transport properties and interphase compatibility between MOF and polymer materials. A series of MOF-based mixed matrix hollow fiber composite membranes have been developed by incorporating different types of MOF crystals (e.g., surface functionalized UiO-66 and ZIF-8) into a variety of polymers (e.g., polymers of intrinsic microporosity, and poly(ether‐block‐amide) copolymers) for highly efficient CO₂ capture. Preliminary results showed that the CO₂ permeance of these MOF-based ultrathin film composite mixed matrix hollow fiber membranes was higher than 1000 GPU with a CO₂/N₂ ideal selectivity of >20. Testing these membranes using real flue gas with humidity and minor contaminants at the National Carbon Capture Center (NCCC) will also be presented. We demonstrated that MOF-based mixed matrix hollow fiber membrane is a very promising platform to provide high-performance and highly scalable gas separation membranes for the application of post-combustion CO₂ capture to minimize the cost of an integrated carbon capture system.