The ultimate clean energy? Scientists create green hydrogen fuel from air

Scientists have discovered a way to turn air into green hydrogen fuel and expect to make the technology available to the public in less than three years.

The team’s findings were published in the journal Nature Communications on Sept. 6. In the paper, the researchers explained that using their invention, which they called a "Direct Air Electrolyzer" (DAE), they were able to electrolyze the humidity in the air and turn it into "green hydrogen."

“This module uses a hygroscopic electrolyte exposed to the atmosphere constantly,” Gang Kevin Li, a lecturer in the Department of Chemical Engineering at The University of Melbourne and co-author of the research, told Newsweek.

“Such electrolyte has a high potential to extract moisture from air spontaneously (without external energy input), making it readily available for electrolysis and hydrogen production once coupled with a (renewable) power supply.”

The DAE can provide hydrogen fuel to remote and dry areas with humidity as low as 4 percent, which Li said is drier than any desert. Furthermore, the paper noted the module has minimal impact on the environment when used with renewable energy. In the case of the study, the scientists used a solar panel for the power source.

“The ability to use moisture from air makes this DAE module applicable in remote, arid and semi-arid environments where the accessibility to fresh water is a big problem," Li said. “Most areas on earth with high solar and wind potentials lack fresh water. For example, a desert is deemed a good place for solar power but no fresh water."

Electrolysis, a process by which an electric current is passed through two electrodes into the water, has traditionally been used to gather hydrogen and oxygen from liquid water. This method would only be effective in areas or regions with a good source of water.

A lot of places with abundant renewable energy sources have limited water supply,” Fan Xiaolei, a co-author of the study from the University of Manchester’s chemical engineering department, said.

Some of the regions on the planet that show promise with good solar and wind energy but have a scarcity of freshwater are North Africa, West and Central Asia, Midwest Oceania and southwest North America.

For the DAE to absorb moisture from the air, researchers used porous materials saturated with electrolytes, like a melamine sponge. The device would then divide hydrogen and oxygen using the trapped water.

The prototype, which only measured one square meter (11 square feet) in size, was able to produce 93 liters (25 gallons) of hydrogen every hour. More impressively, the DAE produced high pure hydrogen for more than 12 days in a row in a 40 percent humid environment, with the Faradaic efficiency measured at around 95 percent.

The DAE could also transport hydrogen to supply cities through gas pipes if the machine is scaled up, Hu Guoping, a researcher from the Ganjiang Innovation Academy at the Chinese Academy of Sciences, said.

“When China reduces the share of natural gas in its energy mix in the coming decades, the existing pipeline network can be used to transport hydrogen from the west to the eastern coastal cities,” Hu said. “At a smaller size, the device can be run in remote areas to power daily life.”

The team plans to increase the size of the DAE to 10 square meters (107 square feet) by the third quarter of next year, Li said.

Li estimated that the larger DAE could support the hydrogen electricity needs for one family in a day, while a DAE the size of a tennis court could produce enough hydrogen fuel for 400 cars yearly.

“We expect the product to be ready for market launch by the end of 2025 at the size of 1,000 square meters and operating in deserts, cold regions, and places with storms,” Li said.