NCT and SANS Investigations of Hydrogen Tanks and Solid State Hydrogen Storage Materials
P. K. Pranzas
1, F. Karimi
1, S. Börries
1, F. Beckmann
1, O. Metz
1, J. Bellosta von Colbe
1, T. Bücherl
2, M. Dornheim
1,
T. Klassen
1and A. Schreyer
11Helmholtz-Zentrum Geesthacht, Institut für Werkstoffforschung, Max-Planck-Str. 1, 21502 Geesthacht, Germany
2Technische Universität München, ZTWB Radiochemie Mümchen RCM, Walther-Meißner-Str. 3, D-85747 Garching, Germany
E-Mail: klaus.pranzas@hzg.de
Hydrogen is one of the most interesting vectors for renewable energy sources regarding storage, transport and conversion of energy for the future, especially for mobile applications.
Reactive Hydride Composites (RHCs) are very promising solid state hydrogen storage materials due to high hydrogen densities, stability and safety. The hydrogen sorption kinetics of RHCs is distinctly improved by high-energy ball milling and the addition of suitable metal- based additives [1].
Hydrogen tanks filled with metal hydride powder or pellets were investigated using Neutron Radiography (NR) and Neutron Computerised Tomography (NCT) with thermal and very fast neutrons. Changes in the powder structure were characterized as well as the hydrogen distribution in the tank volume. A special tank for in situ NR and NCT experiments,
"Flexistore", was developed at HZG, certified for pressures up to 150 bar and temperatures up to 400°C. With Flexistore in situ hydrogen sorption studies can be performed varying the parameters temperature, pressure and metal hydride material. The obtained information about hydrogen distribution and powder bed stability is necessary to optimize the compact tank design, the capacity and the heat transfer inside the tank volume.
Furthermore, small-angle neutron scattering (SANS) was used to study the nanostructure of the hydrogen containing metal hydride matrix in nanocrystalline RHC-systems. This is essential for the understanding of the various sorption processes and possible rate limiting processes in metal hydrides and helps in the development and further optimisation of this new type of hydrogen storage materials.
References
[1] P. K. Pranzas, U. Bösenberg, F. Karimi, M. Münning, O. Metz, C. Bonatto Minella, H.- W. Schmitz, F. Beckmann, U. Vainio, D. Zajac, E. Welter, T. R. Jensen, Y. Cerenius, R. Bormann, T. Klassen, M. Dornheim and A. Schreyer, Advanced Engineering Materials 13, 730 (2011)
