Efficient ways of storing renewable energies belong to the major research challenges of our time. Hydrogen as energy carrier is considered to be a promising option for future energy storage. Due to their high volumetric energy densities solid state hydrogen storage systems are regarded as effective storage media besides high pressure or liquefied gas tanks. An important issue for later mass production are production costs of such materials. Our work shows how the established hydrogen storage material sodium alanate (NaAlH4) [1,2] can be obtained from low cost starting materials. Thereby NaAlH4 is produced by reactive ball milling of commercial NaH and waste aluminum grains under 100 bar hydrogen atmosphere. The mechanochemical synthesis was followed stepwise by means of ex-situ PXD (powder X-ray diffraction) and DSC measurements (differential scanning calorimetry). Furthermore, the synthesis was investigated by in-situ monitoring of the milling vial’s temperature and pressure. The sorption properties of the synthesized material were characterized by Sievert’s method and in-situ SRPXD (synchrotron radiation powder X-ray diffraction). A complete conversion of the starting reactants was obtained.
NaAlH4 production from waste aluminum by reactive ball milling
MILANESE, CHIARA;MARINI, AMEDEO;
2013-01-01
Abstract
Efficient ways of storing renewable energies belong to the major research challenges of our time. Hydrogen as energy carrier is considered to be a promising option for future energy storage. Due to their high volumetric energy densities solid state hydrogen storage systems are regarded as effective storage media besides high pressure or liquefied gas tanks. An important issue for later mass production are production costs of such materials. Our work shows how the established hydrogen storage material sodium alanate (NaAlH4) [1,2] can be obtained from low cost starting materials. Thereby NaAlH4 is produced by reactive ball milling of commercial NaH and waste aluminum grains under 100 bar hydrogen atmosphere. The mechanochemical synthesis was followed stepwise by means of ex-situ PXD (powder X-ray diffraction) and DSC measurements (differential scanning calorimetry). Furthermore, the synthesis was investigated by in-situ monitoring of the milling vial’s temperature and pressure. The sorption properties of the synthesized material were characterized by Sievert’s method and in-situ SRPXD (synchrotron radiation powder X-ray diffraction). A complete conversion of the starting reactants was obtained.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
