The National Energy Technology Laboratory’s Research and Innovation Center (NETL-RIC) is developing new, ultra-high-performance facilitated transport polymer membranes with carbon dioxide (CO2)/nitrogen (N2) gas separation performance that lie above the Robeson Upper Bound for post-combustion CO2 separation. NETL is building a small-scale membrane module using the most promising membrane material and testing it in a real flue gas environment. NETL is also working with industry partners to identify and address potential scale-up issues with the material. Development efforts are consistent with overall goals of reducing the energy penalty and cost of CO2 separation relative to conventional technologies through economic analysis.