(428c) Highly Permeable Rubbery Thin Film Composite Membranes for CO2 Capture from Steel Mills

High-permeance and CO₂-selective membranes are needed to make membrane technology economically viable for large-scale deployment of carbon capture from various industrial point sources such as steel mills. Thin film composite (TFC) membranes are necessary for this practical implementation because they can provide high permeance by forming a thin selective layer on top of a porous support layer. This presentation reports the rational design and fabrication of the National Energy Technology Laboratory’s highly permeable non-aging TFC membrane achieved by: (1) synthesizing a high-performance rubbery selective material; (2) developing a high-porosity membrane support; (3) optimizing coating methods to assemble the two materials into scalable membranes; and (4) scaling up membrane supports and TFCs via a roll-to-roll process. The novel rubbery selective layer material shows mixed-gas CO₂ permeability of 930 Barrer and CO₂/N₂ selectivity of 44, exceeding the 2008 Robeson upper bound. The resulting TFCs yield remarkably high CO₂ permeance of 4,500 GPU and CO₂/N₂ selectivity of 34 at 23 ºC. More importantly, the TFCs of this study not only exhibit excellent performance stability (or non-aging behavior) for 1,000 hours in the laboratory but also maintain their separation properties in a 700-hour field test at the U.S. Department of Energy’s National Carbon Capture Center using real, humid flue gas. This presentation will also cover the design, computational fluid dynamic simulation, 3D printing, construction, and permeation testing of plate-and-frame membrane modules for an upcoming field demonstration at U. S. Steel’s Edgar Thomson Plant in Braddock, PA. The field test will demonstrate membrane-based CO₂ capture from a blast furnace for decarbonization of steel manufacturing for the first time in the U.S. A mobile gas permeation test unit is currently under construction for the field test, which is scheduled to take place in 2025.