(548i) Dynamics of Amine-Oxide Hybrid Adsorbents for Post-Combustion CO2 Capture

Amine-oxide adsorbents have emerged as promising candidates for post-combustion CO₂ capture. Although several amine adsorbents with exceptionally high CO₂ adsorption capacities and selectivities have been synthesized, dynamic properties of these materials are not well understood. The limited studies reported in the literature use isothermal models to interpret kinetic data. Given the high heats of CO₂-amine adsorption, this assumption needs to be tested rigorously. In this work, we carry out a detailed investigation into the heat and mass transfer dynamics of amine adsorbents in a packed bed operating in breakthrough mode to better understand the impact of heat evolution on CO₂ adsorption kinetics. Mass and heat transfer models are used to interpret concentration and temperature front measurements obtained from packed bed experiments. Both heat and mass transfer dynamics are modeled successfully. We found that amine loading has a significant effect on CO₂ diffusion properties, which in turn influences the breakthrough performance of these materials. The kinetic properties of these amine adsorbents provide insights that may help guide the design of optimal adsorbents for practical applications.