Hydrogen, most A common element in the universe, it has long been touted as a clean and abundant alternative energy source. But the easiest way to make hydrogen fuel requires pure water, which can be hard to come by, and will only get harder amid worsening droughts around the world.
Now, in a study published this week in the journal nature communicationsScientists have revealed a new way to produce hydrogen fuel.
What’s new – They found that all you need is the moisture that floats naturally in the air, along with their new device that swallows moisture and spits out hydrogen and oxygen. His method could stimulate the production of hydrogen fuel anywhere on the planet.
Here is the background – When hydrogen reacts with oxygen in fuel cells that generate electricity, it only leaves behind water, unlike fossil fuels, which emit pollutants in the process. The electricity then splits the water molecules into hydrogen and oxygen gases, a process known as electrolysis.
Currently, hydrogen research aims to harness solar power or other renewable energies to create hydrogen fuel from water, all without harming the environment.
But this strategy “will require a significant amount of fresh water, and this can be challenging in places where water supply is a big problem,” says study author Gang Kevin Li, a chemical engineer at the University of Melbourne in Australia.
More than a third of Earth’s land surface is arid or semi-arid, but these areas nonetheless manage to support about 20 percent of the world’s population, Li and colleagues note.
Fresh water is extremely difficult to access for survival purposes in these dry regions, much less to produce hydrogen fuel. Pollution, climate change and water-guzzling factories only exacerbate concerns about water scarcity.
And while desalination can release seawater for hydrogen fuel production in coastal areas, this significantly increases the cost and complexity of the process.
“Most of the areas on Earth with high solar and wind potential lack fresh water,” adds Li. “For example, a desert is considered a good place for solar energy, but it doesn’t have fresh water.”
What did you do – Previously, Li researched ways to purify smokestack gases to capture carbon dioxide inside, so he understood how to trap gases from the air. So when Li’s research expanded to hydrogen production and the search for fresh water, reflection on his past work gave way to a eureka moment.
To see if his concept would work in regions with low water and low humidity, Li checked the relative humidity of the air in Alice Springs, an Australian city next to the famous Uluru Rock deep in the country’s central desert.
He noted that Alice Springs had an average relative humidity of 20 percent throughout the year. Since this was much more moisture than they needed, electrolysis of air was definitely possible, even in some of the harshest environments.
In their experiments, the researchers used renewable energy from solar and wind power to operate a device that could generate hydrogen fuel from water in the air with about 95 percent efficiency.
The device in question is made of a spongy, porous material that can absorb moisture from the air, somewhat like the silica gel packets found in our beef jerky packaging. Electrodes at each end then convert the molecules into hydrogen and oxygen.
“This work reported the first technology that can directly produce high-purity hydrogen from air without using a liquid water feed,” says Li. “This technology can potentially enable green hydrogen in areas that suffer from water scarcity, such as Central and West Asia, North Africa, Central Australia and Western America, which are also solar-abundant areas.”
Why does it matter? Under laboratory conditions, the new method could operate for more than 12 consecutive days and create hydrogen from air with as little as 4 percent humidity under laboratory conditions. By comparison, in the drought-stricken Sahel region that stretches from eastern Senegal to Eritrea, the average relative humidity is around 20 percent.
The scientists also tested their invention outside the University of Melbourne campus, where temperatures ranged from 70 to 100 degrees Fahrenheit and relative humidity ranged from 20 to 40 percent. On a hot, sunny day, five modules, each with about 3 square inches of surface area to produce hydrogen from the air, could generate 130 cubic feet of fuel per day.
The potential environmental impact of this device that collects water from the air is probably negligible, Li says. For example, to supply all Alice Springs residents and visitors with hydrogen using the team’s technology, the relative humidity of the air around them would only drop by 0.02 percent.
Whats Next – Scientists have just been offered cash venture capital to further their research. In the future, his goal is to test a 107-square-foot version of his device in harsh environments, such as a desert, frozen zone or stormy area, Li says.
Editor’s Note: On September 9, 2022, this post was updated to remove an editing error. The technology probably wouldn’t be viable on Mars.