Australian researchers have developed a device that uses solar energy to extract moisture from the air and produce hydrogen. Such an approach could in particular be used to manufacture fuel in isolated and arid regions.
Producing hydrogen from air
L’hydrogen low carbon is seen as a key driver for the decarbonization of heavy industries such as steelmaking. However, efforts to produce this gas using renewable electricity and electrolyzers to separate water into its constituent elements, hydrogen and oxygen, have come up against a problem: many parts of the world benefiting from ‘strong sunshine does not have enough water.
This situation led Gang Kevin Li of the University of Melbourne and his colleagues to develop an experimental device capable of extracting water from the air and using electrolysis to produce hydrogen, powered by solar panels or a wind turbine. His team discovered that sulfuric acid was the best material for absorbing water, and successfully used it to produce hydrogen with a high degree of purity.
” It’s the first technology capable of producing hydrogen directly from the air, and you can do it anywhere on Earth, as long as you have a power source. “, specify the authors of the study, published in the journal NatureCommunications.
The device was able to extract water from air with a humidity level of 4%, when average levels in desert areas are around 20%. According to the researchers, such performances make it possible to consider the use of this technology to produce hydrogen in places such as central Australia and the Middle East. It could also work in remote areas and help off-grid villages compensate for intermittent solar power supplies.
A complementary approach
According to Li, technology could easily be scaled, either by making versions of the prototype about one meter high, or by assembling several in a modular way. The researcher believes the approach would be complementary to existing production methods (which include making hydrogen from fossil fuels using a process called steam methane reforming) rather than competing with them.
As the device has been used for the most part in the laboratory, the next step will consist in carrying out extended tests outdoors, including in a desert, in order to study how it behaves when exposed to different elements (dust in particular).
A few months ago, another Australian team unveiled a cheap approach to storing oxygen in powder formpromising to significantly reduce the environmental footprint of the petrochemical industry.