via RMIT University
Researchers have developed a cheaper and more energy-efficient way to make hydrogen directly from seawater, in a critical step towards a truly viable green hydrogen industry.
The new method from RMIT University researchers splits the seawater directly into hydrogen and oxygen – skipping the need for desalination and its associated cost, energy consumption and carbon emissions.
Hydrogen has long been touted as a clean future fuel and a potential solution to critical energy challenges, especially for industries that are harder to decarbonise like manufacturing, aviation and shipping.
Almost all the world’s hydrogen currently comes from fossil fuels and its production is responsible for around 830 million tonnes of carbon dioxide a year*, equivalent to the annual emissions of the United Kingdom and Indonesia combined.
But emissions-free ‘green’ hydrogen, made by splitting water, is so expensive that it is largely commercially unviable and accounts for just 1% of total hydrogen production globally.
Lead researcher Dr Nasir Mahmood, a Vice-Chancellor’s Senior Research Fellow at RMIT, said green hydrogen production processes were both costly and relied on fresh or desalinated water.
“We know hydrogen has immense potential as a clean energy source, particularly for the many industries that can’t easily switch over to be powered by renewables,” Mahmood said.
“But to be truly sustainable, the hydrogen we use must be 100% carbon-free across the entire production life cycle and must not cut into the world’s precious freshwater reserves.
“Our method to produce hydrogen straight from seawater is simple, scaleable and far more cost-effective than any green hydrogen approach currently in the market.
“With further development, we hope this could advance the establishment of a thriving green hydrogen industry in Australia.”
A provisional patent application has been filed for the new method, detailed in a lab-scale study published in Wiley journal, Small.
Splitting the difference: a catalyst for seawater
To make green hydrogen, an electrolyser is used to send an electric current through water to split it into its component elements of hydrogen and oxygen.
These electrolysers currently use expensive catalysts and consume a lot of energy and water – it can take about nine litres to make one kilogram of hydrogen. They also have a toxic output: not carbon dioxide, but chlorine.
“The biggest hurdle with using seawater is the chlorine, which can be produced as a by-product. If we were to meet the world’s hydrogen needs without solving this issue first, we’d produce 240 million tons per year of chlorine each year – which is three to four times what the world needs in chlorine. There’s no point replacing hydrogen made by fossil fuels with hydrogen production that could be damaging our environment in a different way,” Mahmood said.
“Our process not only omits carbon dioxide, but also has no chlorine production.”
The new approach devised by a team in the multidisciplinary Materials for Clean Energy and Environment (MC2E) research group at RMIT uses a special type of catalyst developed to work specifically with seawater.
The study, with PhD candidate Suraj Loomba, focused on producing highly efficient, stable catalysts that can be manufactured cost-effectively.
“These new catalysts take very little energy to run and could be used at room temperature,” Mahmood said.
“While other experimental catalysts have been developed for seawater splitting, they are complex and hard to scale.
“Our approach focused on changing the internal chemistry of the catalysts through a simple method, which makes them relatively easy to produce at large-scale so they can be readily synthesised at industrial scales,” Loomba said.
Mahmood said the technology had promise to significantly bring down the cost of electrolysers – enough to meet the Australian Government’s goal for green hydrogen production of $2/kilogram, to make it competitive with fossil fuel-sourced hydrogen.
The researchers at RMIT are working with industry partners to develop aspects of this technology.
The next stage in the research is the development of a prototype electrolyser that combines a series of catalysts to produce large quantities of hydrogen.
Original Article: How to make hydrogen straight from seawater – no desalination required
More from: Royal Melbourne Institute of Technology
The Latest Updates from Bing News
Go deeper with Bing News on:
Hydrogen from seawater
- Green hydrogen produced from waste water
Alpha phase outputs show that the membraneless electrolyser prototypes achieved at least 94 per cent purity hydrogen from direct electrolysis of nine different impure water sources, with 94.9 per cent ...
- How the Navy Is Fighting Climate Change With Action on Clean Energy
Nearby, another project on display at the lab pulls carbon dioxide and hydrogen from seawater. When combined, the result is a fuel that can be used in aircraft. The process requires quite a bit of ...
- Can this ocean-based carbon plant help save the world? Some scientists are raising red flags
It works like this: The plant pumps in seawater and runs an electric current through it, separating it into four components: two liquids, one acid and one alkaline, and two gases, hydrogen and oxygen.
- Can we get limitless green hydrogen by splitting seawater?
But there’s a catch. The devices currently used to split water molecules to make hydrogen — called electrolysers — require ultra-pure water to function. And seawater is full of dissolved ...
Go deeper with Bing News on:
Hydrogen production
- Understanding the Challenges of Long-Distance Hydrogen Transport & Storage
Over the years, hydrogen has gained acclaim as a clean and efficient alternative to conventional fossil fuels such as coal and natural gas. The International Energy Agency notes that global use of ...
- Cepsa selects Siemens, Thyssenkrupp electrolyzers for green hydrogen hub in Spain
Spanish energy company Compañía Española de Petroleos has named Siemens Energy (OTCPK:SMEGF) (OTCPK:SIEGY) and Thyssenkrupp Nucera (OTCPK:TYEKF) (OTCPK:TKAMY) as electrolyzer suppliers for Phase 1 of ...
- Siemens Energy to Supply Green-Hydrogen Technology to Cepsa in Spain
By Michael Susin Cepsa said it has selected Siemens Energy for the supply of electrolysis technology for the production of green hydrogen in southern ...
- Cepsa Selects thyssenkrupp nucera as Preferred Supplier of a 300-MW Electrolyzer for Green Hydrogen Plant in Spain
Cepsa Selects thyssenkrupp nucera as Preferred Supplier of a 300-MW Electrolyzer for Green Hydrogen Plant in Spain Integration of a 300-MW electrolyzer featuring alkaline water electrolysis technology ...
- Thyssenkrupp Nucera to Supply Cepsa With Electrolyzer for Green-Hydrogen Plant in Spain
By Andrea Figueras Thyssenkrupp Nucera said it was chosen by Spanish energy company Cepsa to supply a 300-megawatt electrolyzer for a green-hydrogen plant ...