An innovative electrolyser design that uses steam to produce green hydrogen rather than water has completed its first successful road test in a real world setting.
The solid oxide electrolysis (tSOE) technology technology – a modular assembly of tubes about half a metre long – has been installed at BlueScope’s Port Kembla Steelworks in New South Wales where it has run without incident for over 1000 hours.
This system has been the product of seven years of work by a team of 14 scientists from CSIRO and in partnership with Hadean Energy which has licensed the technology and has ambitions to build a 250 kWh demonstration system.
Conventional hydrogen electrolysers work by splitting water into hydrogen and oxygen, but the new technology developed by CSIRO passes 750C waste heat generated in heavy industrial processes through a series of ceramic tubes.
An electric current is run along the walls of these tubes which splits the high temperature steam into hydrogen and water.
The modular design of these tubes promises to reduce the cost of manufacturing, reduces production costs by 30 percent, allowing the system to make hydrogen at less than 36 kWh a kilo.
CSIRO Senior Principal Research Scientist and Group Leader Dr Sarb Giddey says the use of steam is important in lowering costs of green hydrogen.
The lion’s share of variable production costs for renewable hydrogen are in electricity, and a 30 per cent reduction in the electricity required – by using this steam-based technology – could be a game changer for the industry.
Giddey says that with the trial run serving as proof of concept, the question now was how to scale up the system to provide the amount of hydrogen needed for use applications such as iron and steelmaking, or ammonia production.
“There are two factors that are really critical to decarbonising iron making and steel making – one is the cost of hydrogen, the other is the scale we can produce at,” Giddey said.
“We are looking at tonnes and tonnes of hydrogen being produced. If you look at the scale required for iron and steel making, it’s a lot of hydrogen. You have to replace the coal.”
According to the International Energy Agency, the steel industry globally accounts for 2.8 gigatonnes of CO2 emissions each year, or 8 percent of total energy system emissions.
Hydrogen is expected to be essential in helping to decarbonise iron and steelmaking processes but it is currently made using gas or coal.
Some proposals have sought to use carbon, capture, utilisation and storage to remove the CO2 from the steel production process, but a recent analysis by IEEFA took a dim view of the approach.
Of the six proposed steelmaking projects that are seeking to rely on CCUS, the analysts found all lack transparency about key details on the projects including capture capacity and storage type. Two of three projects considered in “advanced development” do not have dates by which they expect to enter production.
The world’s only operational commercial-scale CCUS project for steelmaking, the Al Reyadah project in the United Arab Emirates, only manages to capture a quarter of its emissions, the analysts found.
CSIRO’s green hydrogen technology has been licenced to Hadean Energy which is seeking to develop a modular design.
A showcase of a 5kW demonstration unit as part of the Australia-UK Renewable Hydrogen Innovation Partnership is in planning.
Under this partnership the company is working to build a small 5kW electrolyser for use in a UK powerplant run by French nuclear energy giant EDF.
