Energy

Storage in carbon nanostructures

An extremely recent experimental technology for hydrogen accumulation consists of using carbon nanostructures (carbon nanotubes and nanofibres), i.e. microscopic structures made of carbon fibres inside which it is possible to store a certain quantity of hydrogen. Discovered at the beginning of the ‘90s, they are showing a good capacity to absorb hydrogen, with sometimes impressive results. Several research groups are working on these materials, but the results obtained so far are still contrasting and difficult to compare, since the tests were made on samples of different materials, at very different pressure and temperature conditions.
Storage in crystal micro-spheres
A new promising technology to store hydrogen is based on the use of crystal micro-spheres with 25-500 micron diameter (a micron corresponds to a thousandth of a millimetre) and with walls that are a micron thick. When heated up to 400°C, the crystal wall of the micro-spheres becomes permeable to hydrogen. In this way it is possible to “trap” the gas inside them and transport it as fine dust in low-pressure micro-spheres. The extraction of hydrogen is obtained by heating the micro-spheres that, after being emptied, can be filled again. Hydrogen can be released also by breaking the spheres, although in this case they could not be recycled.