As countries around the world commit to ambitious emission reduction targets, there’s a phrase which is becoming more and more common from world leaders – green hydrogen.
According to Edith Cowan University’s Professor Hongqi Sun, green hydrogen is the holy grail of future energy sustainability. However, there are significant hurdles to overcome before the green hydrogen dream is realised.
“While hydrogen is the most common element in the universe it’s very rarely found by itself,” Professor Sun said.
“Hydrogen is normally found attached to another element, most commonly oxygen, as part of H2O, i.e. water.”
Splitting water into hydrogen and oxygen can be a relatively simple process via electrolysis, where an electrical current is run through water, splitting the molecules apart. It’s so simple that it’s a common high school science experiment.
Hundreds of billions of dollars are now being invested in the pursuit of a clean way of producing hydrogen.
However, electrolysis at an industrial scale requires enormous amounts of electricity.
Around the world, hundreds of billions of dollars are now being invested in the pursuit of a clean way of producing hydrogen.
Harnessing solar energy
Professor Sun and his team are developing photocatalysts, which are light activated materials that can accelerate the process of producing green hydrogen whilst improving energy efficiency.
“This process mimics natural photosynthesis, where plants turn sunlight, water and carbon dioxide into oxygen and biomass,” he said.
“We are trying to conduct a similar reaction using water, sunlight and perfectly designed chemical catalysts to produce pure hydrogen and oxygen.”
These chemical catalysts are the key to unlocking hydrogen and are precisely manufactured to convert as much water to hydrogen and oxygen as quickly and efficiently as possible.
Professor Sun said true green hydrogen is still years away. However, these same processes can also be used to extract hydrogen from fossil fuels.
This is known as blue hydrogen and is a potential stepping-stone to eventual carbon neutral production.
If we’re successful these tiny catalysts could unlock incredible new ways of producing vital chemicals in a far more sustainable and environmentally friendly way.
There is also massive potential for use of catalysts in the production of ammonia. It’s a crucial ingredient in fertilisers vital for world food production.
However, ammonia production hasn’t changed much in the last century and is also energy intensive, accounting for two to three per cent of global carbon dioxide emissions.
“If we’re successful these tiny catalysts could unlock incredible new ways of producing vital chemicals in a far more sustainable and environmentally friendly way,” he said.
Australia's hydrogen boom
Located in Western Australia, ECU is perfectly placed to capitalise on the green hydrogen boom.
Three new hydrogen electrolyser plants worth more than $100 million have been approved by the Australian Renewable Energy Agency. Two will be located in Western Australia.
The Yara Pilbara Fertiliser plant will produce hydrogen as part of a 10-megawatt electrolyser facility in its existing ammonia facility in Karratha in the State’s North West.
A similar sized project, utilising blue hydrogen processes, is slated for WA’s Mid-West. Hydrogen will be blended with the State’s liquefied natural gas to reduce its carbon footprint.
In announcing funding for the projects, Federal Energy Minister Angus Taylor said the projects would use existing industries and provide a boost to the fledgling sector in Australia.
Today, almost every new home in Australia is built with a solar power system on its roof. One day, I hope solar hydrogen plants could be just as ubiquitous.
"The key here is for us to build the infrastructure and to get the R & D done so we can get the costs down. We can provide the supporting infrastructure and then the private sector can invest on the back of that,” he said.
Resources giants Woodside Energy and Fortescue Metals Group, both based in Perth, have also committed to green hydrogen projects in Western Australia.
The future of hydrogen
Professor Sun believes the renewed focus on hydrogen in Australia is a promising step toward green hydrogen becoming a reality.
“Australia has huge advantages with enormous potential for renewable energy, particularly wind and solar,” he said.
“Today, almost every new home in Australia is built with a solar power system on its roof. One day, I hope solar hydrogen plants could be just as ubiquitous.”
His recently published book Solar-to-Chemical Conversion: Photocatalytic and Photoelectrochemical Processes provides an overview of research in the area, with submissions from colleagues from around the world.