What is green hydrogen, how does green ammonia fit in, and could they pave Australia’s way to a renewable future?
By Sourced Externally
October 17, 2021
Green hydrogen — it might sound like something out of a Superman comic but one of Australia’s richest men is betting on the substance to make Australia a world leader in renewable energy while creating jobs in the process.
He also revealed that his company Fortescue Future Industries would be conducting a feasibility study looking into making green ammonia from hydrogen at an existing ammonia production facility near Brisbane.
The investments are aimed at producing a fuel source from green energy – in this case hydrogen of the green variety.
“Green hydrogen is an energy carrier – but unlike fossil fuels, it’s becoming cheaper, it will never run out – and we won’t cook the planet,” Mr Forrest said in an address to the National Press Club on Wednesday.
What is green hydrogen?
The gas is called “green” because of how it is made.
It is classified as “green” when it is produced with a renewable energy source.
Hydrogen made using other energy sources like fossil fuels is usually described as grey or brown hydrogen.
There is also blue hydrogen, which is produced using the same process as brown hydrogen but the carbon dioxide that would normally be released is caught and stored underground.
Green hydrogen is considered a power source that might one day replace fossil fuels and trials are already underway in Australia of hydrogen powered vehicles and buildings.
So where does green ammonia fit in?
Mr Forrest wants to turn hydrogen into ammonia as the ammonia can be easier to store and transport.
The ammonia itself can also be used a fuel source or converted back to hydrogen.
If the hydrogen used to produce the ammonia is green and any power used in the process is also from a green energy source, then the ammonia is also called “green”.
Mr Forest is partnering with Incitec Pivot, which is Australia’s largest fertiliser supplier to look at converting the company’s existing ammonia production facility at Gibson Island near Brisbane to run on green hydrogen.
Will the projects succeed?
Professor of Physics at Griffith University Evan Gray thinks they will.
“I’m really excited about it. This makes lots of sense. I have waited for this to happen for more than 30 years and I couldn’t be happier,” said Professor Gray, who has worked on materials for solid state hydrogen storage.
Professor Gray said ascribing colours to the hydrogen was confusing but would soon be clarified by the introduction of a certification system that will certify how the gas has been produced.
He said the process to convert green hydrogen requires significant electricity, but this did not mean the production plants would have to be surrounded by solar panels or wind turbines.
He said the producers could buy green electricity from the grid through a power trading agreement.
Where will the water to produce green hydrogen come from?
Professor Gray said another key ingredient needed for the production of hydrogen was water, but this could come from a variety of sources.
Yes, it uses a reasonable amount of water but when you compare water use in generating hydrogen to cooling water in all sorts of other industries, it’s very small,” he said.
Professor Gray said electrolysers require very pure water, but this can be obtained from “cleaned-up” grey water or even sea water.
And he said when you use the hydrogen at the other end, you get the water back.
“You take the water from the hydrosphere and then it ends up back there. So the water goes around and around.”