"Green" hydrogen can be extracted from the air

The most desirable method of hydrogen production - the production of hydrogen from water by electrolysis - consumes a lot of energy. The optimal solution would be to use energy from so-called renewable sources. Professor Gang Kevin Li from the University of Melbourne has a method for making Hydrogen made of air with a humidity of only 4%. This paves the way for them hydrogen production in semi-arid areas where there is the greatest potential for so-called renewable energy, but there is no access to sufficient water.

Currently, most of the hydrogen produced is derived from natural gas or coal. Greener methods of making it are being developed around the world.

Li and his team decided hydrogen from the air to win. At any point in time there is about 13 trillion tons of water in the atmosphere. It occurs even in semi-arid areas. The Australian scientists obtained hydrogen from the air with a high purity of 99 percent. Their prototype plant was in operation for 12 days. In that time they could, on average, almost 750 liters Hydrogen per day and square meter electrolyser.

Image source: Pixabay; Which

The researchers first soaked a sponge or foam with a water absorbing electrolyte and then put it between the electrodes. The water extracted from the electrolyte is spontaneously transported to the electrodes by capillary forces. at the cathode Hydrogen generated, at the anode Oxygen. This is a completely passive process. No moving parts are needed, says Li.

The device was used with both Solar cells as well as with a small one Wind turbine operated alone. It works both indoors and outdoors, and the efficiency of converting solar energy into hydrogen is 15%.

If the financing is secured, a prototype with an electrode area of ​​up to 10 m^2 should be built next year. Its developers also want to create a cheaper and more efficient electrolyser.