We ve also resolved the thermodynamic issues of storing and releasing hydrogen from the metal hydride so a typical fill up would require only three or four minutes. ECD s Vice President of Advanced Materials Development, Dr. Rosa Young, defines a metal hydride system as hydrogen gas, engineered metallic materials, and the interface region between them. She says, The metal alloys we have formulated are in loose, dry-powder form. Hydrogen gas entering the storage vessel absorbs onto the interface regions of this powder. H 2 molecules disassociate into individual hydrogen atoms and a metal hydride is formed when these atoms arrange in a specific pattern with the metal atoms.
Heat is also a factor.
Removing heat drives the aforementioned adsorption process. Adding heat reverses the chemical reaction and causes the hydrogen atoms to reform as H 2 molecules. The resulting pure hydrogen gas can then be fed directly to a fuel cell which, in turn, produces the electrical energy to power a car. The beauty of the metal hydride approach is that hydrogen atoms reside very close together in the metal matrix. Even though the weight of the metal matrix is substantially greater than the stored hydrogen, the energy storage density is significantly higher than what s possible with gaseous or liquid hydrogen.