(508a) CO2 Adsorption on 13X Monolith Using Volumetric and Chromatographic Techniques

In recent years, the ever-increasing development of manufacturing techniques has enabled the production of a wide range of structured adsorbents designed to address some of the shortcomings of conventional pelletised materials. Channel shapes and flow patterns are engineered to minimise pressure drop, improve adsorption/desorption kinetics and maximise accessibility to the active material. The main challenges in this area of research are commonly associated with the synthesis and production processes. However, it is often overlooked that testing and characterising structured materials is equally challenging. Monoliths are produced in a variety of shapes and sizes and this often prevents the use of the most conventional adsorption techniques. Most of these systems (e.g., microbalances and commercial volumetric apparatuses) are generally designed to minimise dead volumes, with small sample units and limited accessibility, limiting significantly the possibility of testing the entire monolith.

In this work, we present a rigorous and systematic methodology for the characterisation of gas transport kinetics in monoliths using a combination of volumetric and chromatographic techniques. The approach is validated by measuring the CO₂ mass transport kinetics in an extruded 13X monolith manufactured at Vrije Universiteit Brussels.

Volumetric kinetic tests were carried out using a novel Adsorption Differential Volumetric Apparatus (ADVA) designed to measure accurately very fast kinetics [1]. ADVA has also a modular design that allows the uptake cell to be adapted to samples of different sizes and shapes, making it ideal for the characterisation of structured adsorbents. Kinetic tests on ADVA were carried out on fragments at different pressure levels and on the entire monolith.

Additional kinetic tests on the fragments from different sections of the monolith were carried out using the Zero Length Column (ZLC) [2]. Finally, breakthrough experiments on the whole monolith were used to validate and reconcile the information obtained from the different techniques.

The methodology shows how a combination of measurements on fragments and whole monolith across different techniques can be used to predict the process performance of the material and provide insights on the manufacturing process.

References

[1] S. Kalaitzopoulos, E. Mangano, S. Brandani, B. Corey, and K. Weston, Ind. Eng. Chem. Res. 63, (2024) p. 18552.

[2] S. Brandani, E. Mangano, Adsorption 27, (2021), p. 319.

[3] R. Mennitto, I. Sharma, S. Brandani, AIChE J. 68, (2022), e17650.