Speaker
Description
Thanks to their perfectly tailored framework topologies, small-pore zeolites have received much attention in the last years for separation of small gases with high added values.[1]. However, finding the best zeolites for such task is not easy since many parameters have to be synergistically screened. In this context, we present a comprehensive study mixing DFT calculations and molecular dynamics simulations to isolate the best formulations for CO2 separation. This first step led to the template-free synthesis of stable Na-GIS followed by partially ion-exchange with Mg2+ cations. The parent Na-GIS and partially-exchanged NaMg-GISs were thoroughly characterized using state-of-the-art techniques, and studied for their applicability for CO2 adsorption and CO2/N2/CH4 separation through single component adsorption at both low and high pressures and dynamic breakthrough curve analysis methods. In all cases, deep investigations were conducted using advanced and high-precision sorptiometry to understand the effect of the network dimensionality, flexibility and accessibility on the resulting adsorption behaviour and heat of adsorption values with pure component and gas mixtures. Finally, simplified fast cycling experiments consisting of five complete dynamic cycles were conducted to evaluate the potential of this material in pseudo realistic flow setups. Our findings revealed that NaMg-GIS zeolite exhibits highly promising potential for efficient CO2 separation, outperforming the parent Na-GIS and reference zeolites in both CO2/CH4 and CO2/N2 binary systems. Of particular importance, NaMg-GIS demonstrated an “infinite” selectivity for CO2 in the CO2/CH4 separation at both 25 and 50°C.
