They absorb and compress hydrogen and methane: it's nanosponges, a new material that is already bringing significant advantages in the industrial and automotive fields. In the future, why not, even in medicine. Meanwhile, this discovery made in Italy, the result of project of the University of Milan-Bicocca "H2-Ecomat", is beginning to reach the world of the public and private transport and energy distribution industry. Piero Sozzani, full professor of Industrial Chemistry at the Department of Materials Science, explains what materials they are and above all how, in their being “nano”, they will change the world.
1) Let's define nanosponges: what is it?
They are new materials that belong to the categories of Hyper cross-linked synthetic materials (MIR) and gods Porous materials of biological origin (MPOB). Some of the new materials, for which the patent is already pending, derive from soy, are biodegradable and free of heavy metals: which allows them to be disposed of in organic waste at the end of their life cycle.
2) What properties do they have?
The materials look like a powder and behave like sponges with extremely small tunnels, in the order of nanometers: this prerogative allows the absorption of elusive gases such as hydrogen, methane and carbon dioxide. They have a very high degree of porosity that makes them "sponges”.
If the powder is inserted in a cylinder it is able to reduce the gas pressure, for the same volume, up to 30-80 atmospheres, so, for example, in a one-liter container filled with absorbent material it is possible to store up to 40 liters of methane at zero degrees. The nanosponges they also have the property of releasing the gases at the end of storage, keeping their characteristics unaltered and can be quickly used again.
3) How long have you been working on it and how many? Who finances?
Our team has been actively working in the laboratory for two years: within the Materials Science department and the Physics department, three teachers led a team of about ten researchers between 22 and 32 years of age. It is a two-year project, H2-Ecomat, which has a total value of 750 thousand euros, of which 375 thousand financed by the Lombardy Region and the remainder by our University.
4) The application of nanosponges relating to the increase in the transport capacity of gaseous fuel which implies a greater autonomy of the car: how does it work?
The methane tanks of cars equipped with nanosponges can contain more fuel for greater autonomy and eliminate the risk of explosion: the material can in fact lower the pressure in a gas cylinder from 200 to 30 atmospheres, making on the one hand the car traction gas much safer and on the other the much lighter tank.
5) Cylinders and containers become lighter and less bulky: can we quantify the decrease in weight and understand the practical advantages?
First of all, it must be considered that this aspect strongly depends on the applications and on the type of vehicle that transports these containers. However, a liter bottle full of material can condense even tens of liters of methane in gaseous form without any compression. Taking the example with methane, in a one-liter container filled with absorbent material it is possible to store 40 liters of methane at zero degrees, without compressing it. We can consider transport by ship for example: up to now the technologies commonly applied are those of resorting to very high pressures or liquefying gases at very low temperatures with refrigeration systems, which consume energy continuously.
With the use of nanospongeson the other hand, it would be possible to transport more methane without compressing it and certainly the current risks would be lower. Furthermore, there would be savings in redistribution, thanks to the reduction of regasification costs.
6) There are also applications to plants where carbon dioxide and sulfur gases must be removed from hydrogen and methane: how do they act there? what kind of implants are they? What is the advantage and what do nanosponges replace?
Typically this occurs downstream of hydrogen and methane transport systems and pipelines in which carbon dioxide and sulfur gases must be removed from the gas of interest: nanosponge materials capture contaminating and toxic gases from a flow of gas to be decontaminated , they act precisely by separation.
7) Are there any other applications? And in the future?
We are studying applications in areas where absorption and release are needed, such as in medicine, for drug delivery. We are now entering the phase of technology transfer to companies in the public and private transport and energy distribution sectors. Numerous industries have expressed interest in the results obtained on innovative materials and there are signs of an impact on the recruitment of young people trained by us, who have the ability to follow the path of scale-up and technological implementation of the discoveries. This represents a further example of the effectiveness and excellence of Italian research.