International Journal of Energy Research, Vol.38, No.4, 477-486, 2014
High-temperature activated AB(2) nanopowders for metal hydride hydrogen compression
A reliable process for compressing hydrogen and for removing all contaminants is that of the metal hydride thermal compression. The use of metal hydride technology in hydrogen compression applications, though, requires thorough structural characterization of the alloys and investigation of their sorption properties. The samples have been synthesized by induction - levitation melting and characterized by Rietveld analysis of the X-ray diffraction patterns. Volumetric pressure-composition isotherm measurements have been conducted at 20, 60 and 90 degrees C, in order to investigate the maximum pressure that can be reached from the selected alloys using water of 90 degrees C. Experimental evidence shows that the maximum hydrogen uptake is low since all the alloys are consisted of Laves phases, but it is of minor importance if they have fast kinetics, given a constant volumetric hydrogen flow. Hysteresis is almost absent while all the alloys release nearly all the absorbed hydrogen during desorption. Due to hardware restrictions, the maximum hydrogen pressure for the measurements was limited at 100 bars. Practically, the maximum pressure that can be reached from the last alloy is more than 150 bars. Copyright (c) 2014 John Wiley & Sons, Ltd.
Keywords:Zr-based hydrides;intermetallic compounds;efficient hydrogen storage;AB2 type;hydrogen compressors