Key points
- Hydrogen could help reduce the carbon emissions of heavy industries.
- Green hydrogen is made by electrolysing water in an electrolyser using electricity from renewable resources. But electrolysers use a lot of electricity and can be quite expensive.
- We're creating a company to commercialise our Solid Oxide Electrolysis tech, a highly efficient form of electrolysis, to help heavy industry to create hydrogen.
Heavy industries across the globe are considering ways to decrease their greenhouse emissions in line with the Paris Agreement. Hydrogen has exciting potential as an emerging source of clean energy.
But not all hydrogen is the same. Colours help to differentiate between the types of hydrogen. Let's talk about green hydrogen.
Green hydrogen for the win
It's important to understand how green hydrogen is produced. Water can be converted to hydrogen and oxygen in an electrolyser, but it uses significant amounts of electricity.
If the electricity is produced renewably, for example from solar or wind energy, then no greenhouse gases are emitted during the electricity production or the hydrogen production steps. This is green hydrogen.
Currently, most hydrogen used in industry is produced by reforming fossil fuels such as natural gas, with greenhouse gases as a by-product.
How can hydrogen help reduce industrial carbon emissions?
Hydrogen can be used to decrease the carbon intensity for many industrial processes, including in iron and steel making.
For some iron sources, hydrogen can be used instead of coal or natural gas to reduce iron ore to iron. The process involves heating iron ore pellets with hydrogen gas in a reactor, which causes the oxygen in the ore to react with the hydrogen. This produces water vapour and leaves behind pure iron.
The hydrogen replaces fossil fuel, so the carbon emissions are significantly lower provided the hydrogen was produced without carbon emissions, for example, by electrolysing water using renewable electricity. If it uses green hydrogen, it creates green steel.
Why don’t industries just get an electrolyser?
Electrolysers are expensive and require lots of electricity. Scientists and engineers across Australia and the world are working on the dual problems of manufacturing electrolysers more cheaply and making them more efficient. This means less electricity is required per kilogram of hydrogen.
We're researching several aspects of hydrogen production and distribution, including electrolyser technology, and we think we’ve found a few winning innovations.
Solid Oxide Electrolysis (SOE) hydrogen technology
The most common types of electrolysers are alkaline and proton exchange membrane (PEM) electrolysers. These types of electrolysers are useful in some applications such as smaller scale hydrogen production for hydrogen refuelling stations; but heavy industry is looking for large, highly efficient electrolysers.
That’s where Solid Oxide Electrolysis (SOE) comes in. While alkaline electrolysers use a liquid electrolyte, and PEM electrolysers use a polymer electrolyte, SOE use a solid-state ceramic electrolyte.
SOE operates at temperatures close to 800oC, so part of the energy cost is heating up the water. But heavy industry often has waste heat or low-cost heat as part of their processes. If this heat is used to pre-heat the water going into an SOE electrolyser, then SOE has been shown to use 30 per cent less electricity in comparison to PEM and alkaline electrolysis. This is one of the reasons why SOE is the best type of electrolysis for many industrial applications, where hydrogen can be used as a feedstock in the process itself.
Our tubular hydrogen technology
Our tubular solid oxide electrolysis (tSOE) technology has attracted the attention of industry and investors due to its high energy efficiency. It’s made of ceramic tubes.
Steam runs inside the tubes, and when an electric current is applied, the steam splits into hydrogen and oxide ions. Ceramic membranes are oxide ion conductors and separate oxide ions (as oxygen) from hydrogen at the same time under applied potentials. The rest is pure hydrogen.
When it comes to the cost of manufacturing the electrolysers, our tubular SOE wins again.
Tubular SOE uses a series of sintered ceramic tubes and easily obtainable metals, so they are cheaper to produce. In addition, our SOE technology can efficiently produce hydrogen and syngas (a mixture of hydrogen and carbon monoxide). This is the feedstock for the production of many valued-added chemicals, including ammonia, petrochemical and methanol production. This makes it further distinguishable from PEM and alkaline technologies.
Tubular SOE technology is also highly scalable – the amount of hydrogen produced depends on the number of ceramic tubes inside the electrolyser casing. The tubular design also simplifies the manufacturing process, further reducing manufacturing costs.
From the lab to real world
We’ve shown our tubular SOE technology works well at a lab scale. The next step is to test it at industrial scale. We are working with Australia’s largest steel producer, BlueScope, to build a big electrolyser and test it at their Port Kembla steelworks.
We have also helped to create a new company, called Hadean, to commercialise our tubular SOE technology. By creating a new Australian company we’re able to bring in dedicated human and financial resources and leadership that will focus on driving the technology to a commercial outcome. This will help to decarbonise heavy industry in Australia and around the world.