A new device captures water from the air to produce combustible hydrogen
Designed by a team of researchers from the University of Melbourne, it is a prototype of a solar-powered electrolyzer, capable of using the humidity in the air to produce green hydrogen.
In the process of transitioning from fossil to renewable energy sources, hydrogen is gaining more and more attention, as it has enormous potential as a clean fuel, producing no harmful emissions.
However, its production presents great challenges, both from a practical point of view and a cost point of view, as the separation of hydrogen from water (electrolysis) requires complicated technologies, based among other things on fresh and pure water, something that is not available on more than a third of the earth's surface.
However, scientists have come up with a new method to capture water from the air, before breaking it down into hydrogen and oxygen, developing a device that can work. in areas where the air humidity is just 4%.
The prototype, described in a research article published in the journal Nature Communications a prototype of an electrolyzer powered by solar energy which allows the direct production of hydrogen from the air, that is, it allows the capture site of fresh water from the atmosphere and its electrolysis using electricity produced from renewable energy sources.
In one test, the prototype was run for 12 consecutive days "with stable performance and efficiency around 95%” As explained by Gang Kevin Li of the University of Melbourne, Australia, and his colleagues who have enabled the development of the new device -. With our work, we confirm that the humidity of the air can be used directly for the production of hydrogen by electrolysis, thanks to its universal availability and its natural inexhaustibility.”.
For the test, the researchers connected in parallel five electrolyzers powered by a solar panel, whose electrodes are located on both sides of a water collection unit, captured by a spongy material that absorbs water from the air. and which also acts as an electrolyte reservoir.
Both electrodes have been isolated from the air, which means that hydrogen and oxygen can be collected as pure gases once the split has taken place. “This so-called direct air electrolysis module (AED) can operate in a dry environment with a relative humidity of 4 percent, overcoming water supply problems and producing green hydrogen sustainably with minimal impact on the environment.”The researchers specified.
The technology is still in its early stages but, according to the developers, it can easily be expanded. In particular, through "a further improvement of the surface-to-volume ratio by engineering the channels or increasing the proportions of the spongy material"It will be possible to guarantee a water absorption rate" such as to allow the up-scaling of the AED units ".