Electricity Plus Humidity Makes Green Hydrogen, Scientists Introduce New Discovery

Scientists have discovered a way to create hydrogen, or more precisely, green hydrogen, using only electricity and humidity.

The paper claims that this "green hydrogen" is created by electrolyzing air humidity rather than conventional liquid water, which could make it possible to supply hydrogen fuel in dry and remote regions with little negative environmental impact, especially if renewable energy is used.

The air's water could be electrolyzed by the paper's authors at humidity levels as low as 4%.

Extracting Moisture from the Air

Gang Kevin Li, a senior lecturer at The University of Melbourne's Department of Chemical Engineering, said that they have created a device known as a "direct air electrolyzer," or DAE.

Li is a co-author of the paper.

He added that a hygroscopic electrolyte subjected to the atmosphere continuously is used in this module.

When coupled with a renewable power source, this electrolyte has a high potential for spontaneously extracting moisture from the air without the need for external energy, making it easily accessible for electrolysis and hydrogen production.

Only hydrogen and oxygen have traditionally been extracted from liquid water by electrolysis, which involves submerging two electrodes in the water and passing an electrical current through it.

Electrons are ripped from water at the anode, the positively charged electrode, creating positive hydrogen ions and O2 molecules.

The hydrogen ions receive electrons at the negative cathode, resulting in the formation of hydrogen gas, or H2.

This method has, however, typically required having access to water.

Due to the potential for competition with scarce supplies of drinking water, this restricts the use of liquid water electrolysis to locations where there is a sufficient supply of water.

The DAE eliminates this risk and the associated cost and makes it possible to produce hydrogen anywhere by collecting the water that is already present in the air.

Li explained that this DAE module can be used in remote, arid, as well as semi-arid environments where access to fresh water is a major issue because it can use moisture from the air.

Most of the planet's high-solar- and wind-potential regions are devoid of freshwater.

For instance, a desert is thought to be a good location for solar energy but lacks fresh water.

Even in the Desert

Almost every air environment on earth can use it.

At 4% relative humidity, which is drier than any desert, the group's DAE module was tested.

The Mojave Desert's average relative humidity varies from 10% to 30% during the day and can reach 50% at night, which means that the DAE would still function even in arid regions.

The authors' prototype of this device, which was tested using solar energy as input, had a stable Faradaic efficiency of about 95% over the course of 12 consecutive days, according to the paper.

The rate at which charge is transferred is known as the faradaic efficiency.

This new method has the advantage that it can both consume and generate renewable energy: the electrolysis's electricity can be generated using renewable energy sources like solar or wind power, and the green hydrogen produced can be used as fuel or even to power hydrogen nuclear fusion reactions.

The authors claimed that these findings could help future solar-to-fuel conversion technologies operate anywhere on Earth, solving the issue of water scarcity in the case of widespread hydrogen production.

Li said that the device could be installed in regions with a lack of water but a lot of solar or wind energy.

It would also apply to the production of hydrogen in isolated and dispersed areas, Newsweek reported.