Molecular diffusion enhanced performance evaluation of metal-organic frameworks for CO2 capture

Molecular diffusion is a fundamental property that limits the performance of solid sorbents in carbon dioxide capture and separation applications. Unique to each sorbent, gas diffusion is determined by the physical and chemical interactions that occur between the gas molecules and a sorbent’s surface atoms. At the process level where carbon dioxide capture performance is validated, however, simulations are typically carried out using generalized parameters that omit the structure-specific, molecular kinetics occurring in each sorbent. Here, we report process-scale simulations of carbon dioxide capture performance in metal-organic frameworks (MOF) informed by molecular adsorption predictions that represent the unique structural properties of each MOF. By evaluating a total of 10,143 MOFs for post-combustion carbon dioxide capture, we demonstrate that the inclusion of the material-specific, molecular diffusion dynamics significantly alters their simulated, process-level performance. Specifically, the inclusion of molecular diffusion relegates up to 20% of the MOF candidates of the initial rank-order while the top 27 MOFs exhibit productivity and energy consumption metrics that surpass those of all known materials used in today’s industrial applications. The method could be applied to evaluate a broader class of solid sorbents, including covalent organic frameworks and zeolites. For validation and reuse, we provide access to data and simulation code.