Hydrogen produced from air could provide low-carbon fuel in deserts

The author is Adam Vaughan.

The water in the atmosphere can be used to make hydrogen from the humidity in the air.

Heavy industries such as steel-making use low-carbon hydrogen to decarbonise. Many parts of the world with the most solar power potential to do this don't have enough water to make the gas.

Gang Kevin Li and his colleagues developed a prototype device that can absorb water from the air and use it to make hydrogen using solar panels or a wind turbine. Sulphuric acid was found to be the best material to act as a sponge to capture the water.

It is possible to produce high-purity hydrogen out of the air if you have energy.

The team was able to capture water even at a low humidity of 4 per cent. In places like central Australia and the Middle East, hydrogen production can be viable. It could be used in remote areas to balance intermittent solar energy supplies.

The technology could be scaled up either by making larger versions of the prototype or by stringing them together in a modular fashion. He thinks the approach would complement existing production methods such as making hydrogen from fossil fuels using steam methane reforming, rather than competing with them.

Read more: Green hydrogen is key to building a net zero economy

The team will be testing the device outdoors to see how it handles real-world challenges such as dust.

Simon Bennett at the International Energy Agency said that this approach seems worth exploring. The prototype seems to produce less hydrogen than he would expect from a commercial system with access to fresh water. Considering they run on humidity, that is not really a big deal. Bennett thinks hydrogen will find its competitive advantage if they get the chance to test how a device would work in practice at the larger scales.

Nature Communications was published in the journal.

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