About Hydrogen Storage Technology
Using special vacuum technology from rare-earth and transition metals can be melted alloys, which are able to absorb hydrogen from the gas phase. These alloys, at room temperature and under certain hydrogen pressure, are absorbing extremely large quantities of hydrogen by forming solid metal hydrides. The chemical reaction of hydride formation is accompanied with release of heat into environment. The hydrogen absorption process can be reversed if the hydrogen pressure is lowered below some certain value. In this case, desorption of hydrogen gas is accompanied with heat absorption from environment.
The hydrogen storage alloys, based on rare-earth metals, Ti,
Zr, Fe, et. al, are extensively studied. However, only rare-earth
based so called AB5-type and transition metal based
AB2-type alloys has reached the stage of mass production
and commercialization. At the same time, as a reversible gas storage
material, only AB5-type alloys can operate at moderate
temperatures (from -20°C up to +60°C), while the AB2-type
ones require additional heating.