The National Energy Technology Laboratory’s Research and Innovation Center (NETL-RIC) is developing new, microporous polymeric (m-poly) sorbent technology with a demonstrated carbon dioxide (CO2) uptake capacity of 10 wt% and a selectivity of greater than 500 under a “simulated gas” environment for natural gas flue gas (NGFG). The most promising m-poly sorbents are to be integrated into a prototype modular system for long-term field testing (such as at the National Carbon Capture Center [NCCC]) under actual post-combustion flue gas.