a b s t r a c tA membrane-based pilot plant for carbon dioxide capture from the flue gas of a coal-fired power plant has been installed and operated at the National Carbon Capture Center in Wilsonville, Alabama, USA. The membrane system is sized to treat flue gas containing one ton per day of carbon dioxide. Stable operations for three extended runs conducted over a period of two years have been achieved with both pulverized coal and simulated natural gas flue gas. Carbon capture rates up to and over 90% were achieved with full-scale Polaris™ modules in individual trials that ran up to 1800 h. Both cross-flow and countercurrent sweep spiral-wound modules demonstrated effective and stable carbon capture performance. This paper describes the experimental correlations that were developed, and summarizes the observed performance envelopes resulting from the combination of selected operating process conditions, equipment, and modules.