The pursuit of clean, net zero–emissions energy has received another leg up from engineers in Melbourne. They have boosted 14 times greater green hydrogen production through the power of electrolysis and sound waves.
The achievement could prove instrumental in democratizing hydrogen as an affordable fuel for transportation and other major industries and helping reduce humans’ carbon footprint.
The science and other stuff to know
The study was carried out by RMIT Associate Professor Amgad Rezk and his team, who utilized a novel method of initiating water electrolysis to produce hydrogen. Project leader Rezk thinks “the team’s innovation tackled big challenges for green hydrogen production,” according to a statement on the RMIT University website.
Electrolysis involves splitting water molecules into oxygen and hydrogen and is achieved by running electricity through water using two electrodes. The oxygen and hydrogen are released in bubble form, with the hydrogen produced being ‘green hydrogen.’ However, this green hydrogen has contributed only fractionally to the global volume of hydrogen production as the process requires high energy and is expensive.
“One of the main challenges of electrolysis is the high cost of electrode materials, such as platinum or iridium,” Rezk said. “With sound waves making it much easier to extract hydrogen from water, it eliminates the need to use corrosive electrolytes and expensive electrodes such as platinum or iridium. In addition, water is not a corrosive electrolyte so we can use much cheaper electrode materials such as silver.”
During the study, researchers analyzed hydrogen produced by electrolysis with and without sound waves from the electrical output.
“The electrical output of the electrolysis with sound waves was about 14 times greater than electrolysis without them for a given input voltage,” said Yemima Ehrnst, the study’s first author.
Hydrogen is increasingly considered an alternative fuel because it provides net zero emissions. When hydrogen combustion occurs, the residual product achieved is water, which is entirely harmless to the environment.
Most of the world’s hydrogen production depends on splitting natural gas, but the process results in harmful greenhouse gases being released into the atmosphere. These gases only add to the level of greenhouses, trapping heat on the planet and expediting climate change.
As Rezk said, the ability to use low-cost electrode materials and avoiding the use of highly corrosive electrolytes “were game changers for lowering the costs of producing green hydrogen.”
The researchers believe there is immense potential in exploiting the innovation. Still, we must overcome more “challenges” to integrate sound-wave innovation with existing electrolyzers to scale up the work.
Distinguished Professor and researcher Leslie Yeo said the breakthrough “opened the door to using this new acoustic platform for other applications.”
“We are keen to collaborate with industry partners to boost and complement their existing electrolyzer technology and integrate [it] into existing processes and systems,” Yeo said. “With our method, we can potentially improve the conversion efficiency, leading to a net-positive energy saving of 27 percent,” she added.
The possibilities this innovation can create for attaining an affordable, environment-friendly fuel to power the world sound promising. The researchers have done the groundwork. It’s the industry’s turn to heed now.