Jessica Allen, University of Newcastle and Tom Honeyands, University of Newcastle
Steel is a major building block of our modern world, used to make everything from cutlery to bridges and wind turbines. But the way it’s made – using coal – is making climate change worse.
On average, almost two tonnes of carbon dioxide (CO₂) are emitted for every tonne of steel produced. This accounts for about 7% of global greenhouse gas emissions. Cleaning up steel production is clearly key to Earth’s low-carbon future.
Fortunately, a new path is emerging. So-called “green steel”, made using hydrogen rather than coal, represents a huge opportunity for Australia. It would boost our exports, help offset inevitable job losses in the fossil fuel industry and go a long way to tackling climate change.
Australia’s abundant and cheap wind and solar resources mean we’re well placed to produce the hydrogen a green steel industry needs. So let’s take a look at how green steel is made, and the challenges ahead.
Steeling for change
Steel-making requires stripping oxygen from iron ore to produce pure iron metal. In traditional steel-making, this is done using coal or natural gas in a process that releases CO₂. In green steel production, hydrogen made from renewable energy replaces fossil fuels.
Australia exports almost 900 million tonnes of iron ore each year, but only makes 5.5 million tonnes of steel. This means we have great capacity to ramp up steel production.
A Grattan Institute report last year found if Australia captured about 6.5% of the global steel market, this could generate about A$65 billion in annual export revenue and create 25,000 manufacturing jobs in Queensland and New South Wales.
Steel-making is a complex process and is primarily achieved via one of three processes. Each of them, in theory, can be adapted to produce green steel. We examine each process below.
Read more: Australia could fall apart under climate change. But there’s a way to avoid it
1. Blast furnace
Globally, about 70% of steel is produced using the blast furnace method.
As part of this process, processed coal (also known as coke) is used in the main body of the furnace. It acts as a physical support structure for materials entering and leaving the furnace, among other functions. It’s also partially burnt at the bottom of the furnace to both produce heat and make carbon monoxide, which strips oxygen from iron ore leaving metallic iron.
This coal-driven process leads to CO₂ emissions. It’s feasible to replace a portion of the carbon monoxide with hydrogen. The hydrogen can strip oxygen away from the ore, generating water instead of CO₂. This requires renewable electricity to produce green hydrogen.
And hydrogen cannot replace carbon monoxide at a ratio of 1:1. If hydrogen is used, the blast furnace needs more externally added heat to keep the temperature high, compared with the coal method.
More importantly, solid coal in the main body of the furnace cannot be replaced with hydrogen. Some alternatives have been developed, involving biomass – a fuel developed from living organisms – blended with coal.
But sourcing biomass sustainably and at scale would be a challenge. And this process would still likely create some fossil-fuel derived emissions. So to ensure the process is “green”, these emissions would have to be captured and stored – a technology which is currently expensive and unproven at scale.
Read more: Australians want industry, and they’d like it green. Steel is the place to start
2. Recycled steel
Around 30% of the world’s steel is made from recycled steel. Steel has one of the highest recycling rates of any material.
Steel recycling is mainly done in arc furnaces, driven by electricity. Each tonne of steel produced using this method produces about 0.4 tonnes of CO₂ – mostly due to emissions produced by burning fossil fuels for electricity generation. If the electricity was produced from renewable sources, the CO₂ output would be greatly reduced.
But steel cannot continuously be recycled. After a while, unwanted elements such as copper, nickel and tin begin to accumulate in the steel, reducing its quality. Also, steel has a long lifetime and low turnover rate. This means recycled steel cannot meet all steel demand, and some new steel must be produced.
3. Direct reduced iron
“Direct reduced iron” (DRI) technology often uses methane gas to produce hydrogen and carbon monoxide, which are then used to turn iron ore into iron. This method still creates CO₂ emissions, and requires more electricity than the blast furnace method. However its overall emission intensity can be substantially lower.
The method currently accounts for less than 5% of production, and offers the greatest opportunity for using green hydrogen.
Up to 70% of the hydrogen derived from methane could be replaced with green hydrogen without having to modify the production process too much. However work on using 100% green hydrogen in this method is ongoing.
Read more: For hydrogen to be truly ‘clean’ it must be made with renewables, not coal
Becoming a green steel superpower
The green steel transition won’t happen overnight and significant challenges remain.
Cheap, large-scale green hydrogen and renewable electricity will be required. And even if green hydrogen is used, to achieve net-zero emissions the blast furnace method will still require carbon-capture and storage technologies – and so too will DRI, for the time being.
Private sector investment is needed to create a global-scale export industry. Australian governments also have a big role to play, in building skills and capability, helping workers retrain, funding research and coordinating land-use planning.
Revolutionising Australia’s steel industry is a daunting task. But if we play our cards right, Australia can be a major player in the green manufacturing revolution.
Jessica Allen, Senior Lecturer and DECRA Fellow, University of Newcastle and Tom Honeyands, Director, Centre for Ironmaking Materials Research, University of Newcastle
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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As net-carbon-zero as wind or pv, ane even more fuel-free than a Tesla. What’s not to love?
Once upon a time, an engineer or materials scientist would be required to produce samples for testing. So nice that we live in a world where we can invent things with just words, and fuzzy dinosaurs dance and sing, and stuffed animals practice social sanctions to protect us from the really, really mean people who don’t believe in fairies.
Manufacturing revolution?
/snort/
More energy == more expensive
If there was a better way to make steel, it would have been in use by now. The lack of enthusiasm for hydrogen methods is greatest among those who are in a position to evaluate it. Geoff S
The repeated use of the term “green” in this article is a clear sign the authors are not acting as scientists but rather propagandists. They imply that a method of steel production that is more energy intensive than current methods will be better for the environment because it is “green”. They imply that CO2 emissions are anything but green in spite of the fact CO2 is the building block of all life on our planet, 80% of which is plant matter – i.e. truly green. They do all of this so that they can get wads of cash in exchange for their lost integrity. They sell their souls for a bunch more of that “green” they can put in their wallets.
Yes but the energy for hydrogen production comes from wind so it’s ‘free’ and ‘at no cost’.
Unbelievable they can actually publish such stuff as serious argument.
I lived in Ambridge PA for a number of years before the mills shut down
Worked at two of the big ones J&L and USS Rolling Works both had Bessemer Furnace. That’s where the coal was loaded from below and air was pumped floating the coal on a fluid bed beneath the crucible. J&L also had electric converted direct electrode furnace where the Shippingsport Nuclear facility provided the power.
A by product of low oxygen coal burning called coke was used to increase the carbon in the furnace.Very seldom did we produce a virgin pour mostly we melted down scrap and adjusted teh chemistry too customer spec. At J&L our mill had been originally powered by large water wheels the shaft system was still in the basement of the mill. The 1920s put giant 400HP 480V open frame electric motors at each major tool. As an electrical millwright I was responsible for three machines A 1800s shear 144 inches wide 12 inch thick capacity, A leveler Roller that squeezed 12 inch hot tongue down to 30 Gauge Hot roll and a Slitter that could slit 12 inch tongue. My section of the mill was 4.5 miles from the furnace. In 1978 we began cutting steel for Nippon Steel company out of Japan their product was of high quality and had more consistency than we could do with our equipment.Our Unions paid us an additional 1$ per person per ton of Japanese steel we cut. The owners of the mill determined that it was cheap to buy the steel from Japan than it was to up grade our lines. In the fall of 1979 the mills locked out the unions and all employees then shut down. The union eventually purchased the J&L mill but could not compete with the quality of the new mills in Japan they then decided to scrap the lines and all machines Selling the steel off to China. They never received enough money to even replace one line with all of teh new restrictions and OSHA, EPA regulations.
They ended scrapping teh whole 7 mile long building and all support infrastructure.
Then the EPA came in and declared the site and several other locations around Aliquippa super fund clean up sites seizing all of the money that the union coop had been able to aquire.
I visited in the 1990s and the surrounding towns had become junkyards and meat packing barrios. Just over the hills on both sides of the Ohio river are remediation open ponds where toxic sludge is dredged and air dried for minerals by Asian companies. The steel mills did not collapse from employee cost they collapsed from intentional short term profiteering and communist funded DEMOCRAT political Traitors.
Just like the electronics industry in Florida under Jeb Bush in Florida more than 20 Billion dollars in FAB and assembly facilities have been destroyed to make room for shopping malls and apartment complexes Median income dropped from 78K to 37K in Palm Beach County due to the exact same people following the money from western PA to Florida and damaging a different industry.
Now all of these traitors are heralded a economic genius having swindled the money out of teh people.
The standard politician’s retirement scheme, after their first term in office when they cared about society, is to own real estate when they retire as a result of insider information and inappropriate power brokering. Putting industries out of business, and turning the industrial land into shopping malls and housing developments, with themselves owning some of the land.
In my own city, one Mayor turned out to be owner of land on the right of way of a rail transit development, another was instrumental in the demolition of a hospital due to asbestos insulation, and mysteriously was a part owner in the development company that built condos in the hospitals place.
To be honest this is perhaps addressing the wrong problem. Why use iron and steel at all?
There are two areas where iron and steel are used a lot, one is as a magnetic material and frankly you dont need carbon in it for that, and the second is structural.
But steel is only heavily used because its cheap for its tensile strenght, for cars and aircraft we like aluminium – a more ‘green’ option smelted using nuclear electricity – titanium, plastic or carbon fibre, which obviously is one way to ‘fix’ carbon, to name but two.
Only seriously large structures now still use steel or ferro concrete in bulk – bridges ships, large steel framed buildings and the like and of course railways.
Steel is what we used because coal and iron ore were plentiful: if they cease to be, other stuff will work.
The only things I can think of that would be hard to make without iron or steel would be transformers and electric motors.
But there is no requirement for any structural quality here – hydrogen smelting would probably be good enough
There is not a SINGLE solar panel or wind turbine manufacturer using the energy of their product to make more of their product.
And suddenly, there will be enough electricity produced by these systems to power a hydrogen replacement for coal in steel production.
This is a perfect example of a perpetual motion machine. It is impossible for it to operate, but it is complex enough and runs long enough to appear plausible.
It simply is not.
Having worked the summer after high school in a steel mill I know practically nothing abut making steel except it is a continuous process closely monitored.
My best guess is to continue improving making steel but don’t call it green.
Neophyte urban dilettantes fantasizing.
Blast furnaces are termed “blast furnaces” because air is pumped through the furnace! Which supplies the oxygen necessary to smelt iron oxides into raw iron.
Carbon is freely available from the coke/coal used for fuel.
Clean blast furnaces use coke since it produces a better quality product.
A) the ore is initially processed with coke through a blast furnace to produce molten cast iron with a high carbon/carbides content, over 2%. This part of a steel plant is referred to as the “Iron Works”.
side note: One can usually identify Iron Works employees by their brimstone odor. An odor that sticks to them for weeks. As sulfur is also burned off with scrubbers removing the sulfides from the exhaust.
“Iron Works” is a reduction process that removes oxygen and many other impurities from the iron ore.
From ArcelorMittal:
The blast furnace process uses carbon from the coke and lime and exhausts mostly CO₂.
I am perplexed that the dilettantes writing the above article believe blast furnaces solely produce carbon monoxide (CO). I wonder how they expect to prevent high temperature furnace heat from allowing carbon to capture two oxygen atoms?
B) Molten (preferred) or cooled cast iron ingots are fed into another furnace to further refine the cast iron into steel.
side note: The steel plant I worked at transported molten iron from the Iron Works over to the Open Hearth via rail cars. They also transported rail cars of molten slag to the slag dumps an amazing sight at night.
Again, coke and lime are used to convert iron carbides and graphite into carbon dioxide.
This process takes much longer than the original blast furnace that smelted iron ore into cast iron.
side note: The plant I worked at tapped one furnace a week and poured steel ingots from the melt. They ran 9 furnaces which allowed a two week complete rebuild period for the furnace and necessary support structures without interrupting the flow of steel.
side note 2: Electric arc and Oxygen furnaces processes produce high quality steel quicker than the older blast furnaces. Modern Oxygen furnace operations already capture CO carbon monoxide containing gases for further use in providing power.
Recycled steel/iron is added, samples taken and necessary additives are added to the steel depending upon the steel alloy desired as output.
When they realise replacing coal as a fundamental part of steel making can’t be done, they will start to push for net zero iron..
Just a heads up for what the Greens will be presenting next.
Steel salesman to customer:
“We have two types of steel here; our regular steel and the new, “green steel”, which is the same high quality, but costs 30% more.”
Customer: “Why would I want to buy the green steel if it costs 30% more?”
Salesman: “Because it’s green, and you get to save the planet, and more importantly, your customers get to be saviors of the planet. We’ll even throw in these plaques which say “Planetary Savior” on them, to give to your customers.”
Customer: “So, what are the plaques made of”?
Salesman: “Plastic”.
I love their assumption that making steel using a less efficient process will bring jobs back. Obviously not fans of economics. The reason most steel-making is not done in the USA and Australia anymore is that we can’t compete on cost. It’s partly wages, partly pollution control requirements, and partly the union resisting technological improvements that would reduce the labor intensity.
They only left out a few tiny details like massive overproduction of Chinses steel, uncompetitive labor costs in Australia, and reliance on quotas and tariffs underneath the green steel banner.
I have never seen green hydrogen; how do the get the color to stay on? Is it green enamel? Gloss or Flat? Or can I get this in the color blue?
The bottom line to green steel is the price to make it – if it can’t compete with China’s steel production using coal, then its a non-starter. It would require governments to require you buy it – so more government interference, more government controls, and of course the corresponding economic red-tape that reduces profits and entrenches badly run companies. No thanks.
“But if we play our cards right,” … you’ll still lose because the game is rigged. Best not to play, like China.
“Playing our cards right” includes bluffing when you aren’t dealt a pat hand.
Smoking too much weed is causing wildfires in California. We only have 2 years left.
Oh my. “in theory”, “feasible”, “without having to modify the process too much”. I seem to remember reading these very words, used in much the same manner when reading about cellulosic biofuels and converting porcine manure into oil. Oh, and then there was that cold fusion business.
I suppose diagramming the processes and doing the “theoretical” calculations is a way to keep ones self out of trouble.
I read till this”Australia’s abundant and cheap wind and solar resources” and stopped. More lies from lie spewing liars who lie.
Australia exports almost 900 million tonnes of iron ore each year, but only makes 5.5 million tonnes of steel. This means we have great capacity to ramp up steel production.
Exports of iron ore are a measure of industrial capacity?
Non of the commentators seem to realise that the Lime (actually Limestone) is an integral component of the steel making process. Limestone (CaCO3) decomposes in the heat of the blast furnace to produce Lime ( CaO) and CO2 and the lime functions to remove silica and other acidic contaminants from the molten iron. These include Sulphur and Phosphorous which are converted to their oxides and combine with the lime to form Calcium Silicates, sulphates and phosphates etc. While steel contains small amounts of these materials their presence in large quantities in the final steel is damaging to the properties of the steel.
I wonder if the proponents of the Hydrogen based production of Steel have taken this into consideration?
By the way it is usual to add any required additional ingredients to the steel to the purified product of the blast furnace while it is still molten. So it is possible to add back Carbon to the melt to produce the required grade. Stainless steels are produced by adding Nickel and Chromium to the molten iron and their carbon content may be adjusted according to requirements as well.
When one considers the amount of energy needed to run a blast furnace it seems unlikely to me that it will be possible to use Hydrogen for this purpose. This would require a huge area to be set aside for solar panels or for wind turbines which is only feasible remote from the sources of iron ore, limestone and coke adding transport to the cost of everything else. Furthermore steel manufacture is best run on a 24hour/day basis and requires the use of electricity to control the furnaces and provide power for the blast. So there would need to be sufficient capacity in the generation systems to provide sufficient Hydrogen for the process as well as recharging storage system to allow running through the night.
When you take all of this into account I fail to see that this proposal is in any way feasible.
Green hydrogen. Thar’s your problem.
A blast furnace produces iron, steel is made in a bessemer converter by using oxygen to remove carbon from the iron.
Iron has a large amount of carbon which comes from the coke used to melt the ore. Ask any machinist, iron is dirty to machine as it’s carbon is visible in the swarf. Iron is also a very valuable metal and used for a whole range of products. If a different way is used to melt the ore, do you end up with the iron that meets the desired properties?
I like the way everyone dresses up these lunatic ideas as leading their nations to “leadership” in some green direction (as well as creating “green” jobs everywhere). So Australia could become a world leader in “green” steel, that actually costs more to produce; the UK will become a world leader in making society work on expensive electricity that goes off when the wind doesn’t blow or world leader in having the smallest percentage of car ownership among advanced nations.
I’m tempted to ask, with aspirations like these, how long will they be “advanced” nations?
Anything with green or sustainable in the name is nothing more than wealthy arseholes SCAM!
Hark! A new way to spend money uselessly! Green New Steel (GNS)