280103 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.