(460a) High-Throughput Evaluation of Nanoporous Adsorbents for Post-Combustion Carbon Dioxide Capture

There is significant interest in developing solid adsorbents that selectively adsorb a large amount of CO₂ at partial pressures applicable to CO₂ capture processes, because the significantly lower heat capacities of solids compared to aqueous amine solutions can reduce the amount of energy required for desorbing CO₂. The performance of adsorbents is generally evaluated by gas adsorption isotherms, which are phase-equilibrium analyses at many different partial pressures. Acquiring adsorption isotherms for multiple samples at many different conditions can be a tedious step that limits the rapid screening of materials. Here we report the development and use of a 28-channel high-throughput adsorption analyzer that greatly accelerates this screening process.

 Initially, we evaluated a series of zeolite adsorbents for application in post-combustion CO₂ capture. Based on the CO₂ and N₂ adsorption isotherms obtained, the performance of zeolites at dry flue gas composition and temperature, such as CO₂ uptake and CO₂/N₂ selectivity, was estimated. Then the performance of materials in a fixed-bed adsorber was predicted through breakthourgh simulations. Adsorption kinetics, an important consideration in designing a fixed-bed adsorber, were also investigated. The high-throughput evaluation methodology developed in this work can be applied in the discovery of robust metal-organic frameworks, a new class of nanoporous adsorbents, for the efficient capture of CO₂ from flue gas.