(44b) Hydrogen Adsorption Equilibrium and Kinetics on Maxsorb Pellets at 77K

The current shift towards cleaner and more sustainable energy systems has seen a significant attention towards the use of hydrogen as an alternative and clean energy carrier. One of the many challenges, however, lies in the efficient and safe hydrogen storage. As a result, significant research efforts are currently being directed toward developing advanced materials and technologies for hydrogen storage for a number of large and small-scale applications. In this regard, the key to unlock the potential of storage technologies lies on the design of novel adsorbents with very high porosity, which allow to increase the storage efficiency of the vessel.

The design and development of the storage vessels requires accurate characterisation of the adsorbents. This should include the fundamental equilibrium and kinetic properties of the material at conditions that closely represent the ones used in the final application. The Adsorption Differential Volumetric Apparatus (ADVA), proves to be an essential tool to assess the storage performance of novel adsorbents. The ADVA design, based on the use of a differential pressure transducer across two symmetric branches, ensures high accuracy in the whole pressure range using very small sample masses (<100 mg). This is particularly important when working with weakly adsorbing systems and with prototype adsorbents.

In this work, different pelletised versions of Maxsorb, manufactured by the ECOSTORE-H2 consortium led by the University of Eastern Piedmont, were fully characterised using the ADVA system at the University of Edinburgh. Hydrogen adsorption isotherms were measured at 77K up to 60 bar. In addition, equilibrium measurements at different temperatures were carried out to extract the heat of adsorption. Finally, in order to understand and predict the dynamics and performance of the charge and discharge of hydrogen in the storage vessel, kinetic experiments at various pressure levels were carried out on samples of different dimensions.

Acknowledgments

We kindly acknowledge the National Plan of Recovery and Resilience for the financial support to the ECOSTORE-H2 project