Understanding CO2 adsorption in a flexible zeolite through a combination of structural, kinetic and modelling techniques

DOI: 10.1016/j.seppur.2020.117846

Authors: Maarten C. Verbraeken (University of Edinburgh) , Roberto Mennitto (University of Edinburgh) , Veselina M. Georgieva (University of St Andrews) , Elliott L. Bruce (University of St Andrews) , Alex Greenaway (University of St Andrews) , Paul A. Cox (University of Portsmouth) , Jung Gi Min (POSTECH) , Suk Bong Hong (POSTECH) , Paul A. Wright (University of St Andrews) , Stefano Brandani (University of Edinburgh)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Separation And Purification Technology

State: Published (Approved)
Published: October 2020

Abstract: In this study we show how non-trivial equilibrium and kinetic adsorption behaviour in a flexible zeolite can be understood through a combination of experimental characterisation and modelling. Flexible zeolites, such as those in the RHO-family, can exhibit unusual stepped isotherms in the presence of CO2, but their structural complexity makes it hard to attribute a clear mechanism. Here we present a structural and kinetic study on (Na,TEA)-ZSM-25, an extended member of the RHO-family, and show that by combining diffraction data, lattice fluid modelling and dynamic column experiments, we obtain a plausible mechanism for CO2 adsorption and transport in this material. It is evident that by using any single technique, the behaviour is too complex to be readily understood. This is to our knowledge the first study to measure and model the changing kinetics due to adsorption induced framework flexibility.

Journal Keywords: ZSM-25; Adsorption; Synchrotron X-ray diffraction; Zero Length Column technique; Lattice Fluid

Subject Areas: Chemistry


Instruments: I11-High Resolution Powder Diffraction

Other Facilities: ID31 at ESRF