Thursday, December 31, 2020

Green Steel: DRI, HBI and Finex

I had assumed that the CO2 emissions for making steel with blast furnaces was because of the burning of the coke to provide the needed high temperatures to melt the rocks (iron ore and limestone). And the making of the coke itself also produces a lot of emissions. But I've learned that another source of CO2 in the blast furnace is the reduction of the iron ore. "Reduction" means ripping the oxygen atoms out of the iron ore to leave pure iron. The reduction is done by the carbon atoms in the coke combining with the oxygen atoms in the iron ore to create CO2 and CO. If you grab the oxygen atoms with hydrogen instead of carbon, you create H2O instead of CO2. Of course, H2O is simply water vapor, which is not a greenhouse gas. Powering a blast furnace with hydrogen instead of coke is called direct reduced iron (DRI). An intermediate step towards green steel is using natural gas instead of coke. Since natural gas is mostly methane, CH4, this reduces two of the iron's oxygen atoms with hydrogen instead of carbon. So the CO2 emissions are a third of that emitted when using coke.

This Mitsubishi article below indicates that the cost of hydrogen needs to be an order of magnitude (a factor of 10) cheaper than it is now to be competitive with using coke as the reduction agent. But they expect society will be beefing up the world's hydrogen infrastructure and that those cost reductions will be realized.

safe_image for Mitsubishi Heavy to build biggest zero-carbon steel plant [paycount]
Mitsubishi Heavy Industries will build the new hydrogen steel pilot plant at a complex of Austrian steelmaker Voestalpine.   © Reuters
"Iron ore reduction accounts for much of the CO2 emissions in steelmaking. Japanese steelmakers including Nippon Steel are developing hydrogen-consuming reduction processes based on the conventional blast furnace design. Mitsubishi Heavy's plant adopts a process called direct reduced iron, or DRI. New blast furnaces require trillions of yen (1 trillion yen equals $9.6 billion) in investment. Although DRI equipment produces less steel, the investment is estimated at less than half of blast furnaces. For DRI to attain the same level of cost-competitiveness as blast furnaces, low-cost hydrogen will be key. Market costs for hydrogen now stand at around 100 yen per normal cu. meter, estimates the Ministry of Economy, Trade and Industry. The government aims to get the hydrogen costs down to 30 yen per normal cu. meter by 2030, mainly via mass production. But for DRI to be feasible in the steel industry, 'the level needs to go below 10 yen,' said an executive at a large steelmaker....Mitsubishi Heavy will capture the steel industry's demand for hydrogen to offset the softer growth prospects for thermal power plant equipment."
Jim Hewett Jr.: Interesting. That mill is no stranger to new technology. VoestAlpine is used to being a pioneer in the steel industry. That is where the very first B.O.F. was developed.
Richard Allison: The whole idea is to inject coke oven gas and hydrogen into tuyeres of blast furnaces to reduce CO2 by 50% by 2030. Blast furnaces will still use a little bit of coke and blast furnaces will never be zero percent carbon so HBI and DRI will be using green hydrogen, not gray hydrogen to be produced and melted down in EAFs and replacing blast furnaces. Blast furnaces will start closing down soon but ones still operating by 2030 will have to have 30% cut in CO2 and all of them by 2050. Some steel companies are accelerating this plan to happen sooner. That is one reason AM sold the US operations. This is a win for steel companies because they will be supplying steel to build hydrogen infrastructure and make steel with much fewer steelworkers.

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[At 2:40 it indicates that the process generates carbon monoxide and hydrogen instead of CO2. Both of those gases are combustible. Although the burning of the CO will create CO2.]

safe_image for This Steel Giant Is Winning With a New Brand of Environmentally Friendly Steel
["Econiq" steel. Is it an EAF and carbon credits that make it a game changer? I was expecting the use of hydrogen instead of coal. Actually, in the article they say "To be fair, this isn't a game changer for Nucor per se." The significance of Econiq is that auto manufactures are accepting it for their use. EAFs have had trouble competing with blast furnaces to make steel that is good enough to be stamped into autos because they can't get rid of some of the impurities in the scrap steel.]

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Green Steel is steel that is made in an EAF that is powered by an electric generating plant that uses hydrogen as the fuel. Natural gas emits carbon. Car manufacturers that are "woke" to the green economy will require green certificates that any steel they buy will be green steel.
Green steel is what is going to put integrated steel plants out of business by 2050 or before. That is 28 years from now and many steel companies, especially in Europe are going to have green steel in the next few years. Green Steel is going to cost jobs at the blast furnaces, BOFs, coke plants and sinter plants which will be several thousand in the US alone.
Climate change is real because the Earth is not static and has always run in cycles like the sun that has 11 year cycles. As far as I know, man has not been able to change weather let alone climate. My feeling is that it is easier and cheaper to adapt to changes on the Earth. Ruining country's economies and the middle class that makes the US a great country is not rational and about as irrational as using hydrogen which does not emit carbon (which is not a problem) but takes lots of carbon to produce and distribute.
Check out this video that tells the story better than what I can convey.
John Groves
Here is another new Green Steel technology claiming it will be commercial by 2025.....
Startup promises green steel by 2025 as decarbonisation race heats up
[She is a fan because she think the project will prove that transporting hydrogen as a liquid will fail and that will save investing $300 billion in a hydrogen solution that won't work. (Rosie also has a link to a carbon capture video.) Richard evidently thinks it would be cheaper to build a dyke and locks along our coastline than switch steel to green technologies. I think he is wrong that hydrogen would be used to make electricity to run EAFs. If you have hydrogen, blast furnaces can be run cleanly.]

John Groves posted
Basically, Boston Metal plans to run electricity through the iron ore. This is how aluminum is smelted. To make aluminum for planes in WWII is why the TVA built the 1943 Appalachia and 1945 Fontana Dams in the wilderness. of the Appalachia Mountains. If this works, this would be a lot better than the current plan of making hydrogen with electrolysis.

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