The National Energy Technology Laboratory’s (NETL) Research and Innovation Center (RIC) is developing new, ultra-high-performance membranes and membrane modules for post-combustion carbon dioxide (CO2) capture. The objective of this effort is to deliver an optimized hollow fiber membrane module for CO2 separation from industrial sources under near-ambient pressure conditions. A combination of computational fluid dynamics (CFD) modeling and experimental testing are being used to optimize hollow fiber module design to optimize gas flow distribution, minimize pressure drop, and maximize separation efficiency. The team is using computational tools to optimize the design of the module casing and 3D printing to produce test modules for model validation toward a better fundamental understanding of module design.