Written By: Gwendolyn Dane
Edited By: Carson Riar
"How green hydrogen is replacing coal in the iron and steel industry"
No, it's not colored green. But ‘green steel,’ as the Swedish HYBRIT project calls its product, could play a significant role in helping the world transition away from greenhouse gasses. Our plans for the future rely heavily on our ability to replace fossil fuels with energy from clean sources, and visions of a green, carbon-neutral world often include huge wind turbines cresting hills and photovoltaic cells stretching to the horizon. However, an essential aspect is too often left out of this conversation: the energy and carbon needed to build the infrastructure that generates this electricity. Steel is a huge input in renewable technology of the future, as well as in the buildings and technology we see everywhere today. It is also responsible for just under a tenth of our global carbon emissions, due in large part to the use of coal in the initial refining process (Hoffman, et. al, 2021). This raises an uncomfortable point: we need a carbon-intensive product to build sustainable communities and the infrastructure of the future. Ultimately, it won’t be enough to wean ourselves off fossil fuels for electricity and heat alone–we need to find new ways of producing the materials that make up the very framework of our communities.
The steel industry’s impact on total global carbon emissions is significant, and moving away from inefficient and carbon-intensive production methods will certainly be a necessity to meet the objectives of the Paris Agreement. A report put out by the World Steel Association found that in 2020, producing a single ton of steel released 1.85 metric tons of carbon dioxide into the atmosphere. The same year, almost two billion tons of steel were produced (World Steel, 2021). Proponents of the circular economy might cite steel’s high recyclability as a solution to producing more every year, and there are many cases in which steel can simply be heated and reused to fill the demand for fresh product and reduce the associated externalities. But as long as we face growing urbanization and the pressing need for materials to expand our cities, transmission systems, and wind farms, there is simply not enough in existence to be recycled and meet these demands (Vass, et. al, 2021). Without developing an alternative to steel altogether, or orchestrating a major shift in society and the economy which reduces the factors contributing to demand, solutions therefore rely on cutting out the most carbon-intensive parts of the steel-making process.
Steel begins as iron ore buried deep underground, which is refined and mixed with a tiny amount of carbon. In order to separate the raw iron from the rock, oxygen molecules, and other impurities it is found with, it must be heated to a high temperature in the presence of a reducing agent. In the majority of steel production today, this agent is coke, a heavily concentrated form of carbon which is made by heating coal in the absence of oxygen (American Iron and Steel Institute, 2021). When combined with iron ore and heat in a blast furnace, the coke releases carbon molecules which bind with oxygen in the ore, producing CO and CO2 gasses which exit the furnace and leave behind the pure molten iron . In the process of reducing and purifying the ore, these furnaces release carbon and limestone-based waste known as ‘slag’ into the surrounding environment. This step is the most carbon-intensive part of the steel-making process, and is therefore a target for developing alternative methods with lower emissions (LibreTexts, 2020).
“Hydrogen Breakthrough Ironmaking Technology” (HYBRIT) is one process currently undergoing trials in Sweden, which could present a needed solution to the negative externalities caused by conventional methods of reduction. Instead of using coke and a blast furnace, this process relies on a method known as direct reduction to produce the iron needed for steel (SSAB, LKAB & Vattenfall, 2021). Inside of a reducing shaft, hydrogen gas is mixed with raw iron ore and heated to a lower temperature. Hydrogen molecules bind with the oxygen in the ore, forming water vapor as a harmless byproduct. The result is usable iron in the form of pellets, without the need for coal. Renewable sources provide the electricity needed to split water molecules and form the hydrogen gas, rendering the whole process carbon-free. Since the first pilot plant was built in 2018, HYBRIT has made significant progress, producing enough steel to make a vehicle in collaboration with Volvo in October (SSAB, 2021a). While they are currently operating in a demonstration plant with lower production capacity, the actors behind the technology plan to convert their existing facilities by 2026 in order to operate on a commercial scale. Estimates show that Sweden’s total national emissions could be reduced by ten percent, simply by pivoting away from fossil fuel use in a single industry (Vetter, 2021). However, as a ‘premium product,’ prices are higher for fossil-free steel relative to conventionally sourced material. This is largely driven by costs associated with investments in production and infrastructure, the switch from coal to fossil-free electricity and hydrogen, and from iron ore pellets to HYBRIT sponge iron (SSAB, 2021b). In order to increase the steel’s market share, effective economic or political incentives, such as the Emissions Trading System in Europe, have the potential to increase the competitiveness of such higher-cost, lower-carbon products in future.
A recent accord in October 2021 between the European Union and the United States is one example of how political leadership can help nurture low-carbon innovation and industry. By reducing the tariffs on European steel and aluminum, proponents hope that US imports will shift away from China in favor of the EU. While this may seem like a purely geo-political outcome, it has significant environmental consequences. China’s steel industry is heavily reliant on coal, and produces some of the highest carbon emissions by sector in the world. By contrast, the US and the EU have a higher proportion of scrap recycling plants and electric arc furnaces, which lower the industry’s emissions. By changing incentives to favor suppliers which contribute relatively less to climate change, such trade agreements can have a significant impact on overall carbon emissions, and encourage more countries to move away from carbon-intensive production processes in order to preserve their competitiveness on the global stage (Allan & Tucker, 2021).
Avoiding a climate crisis propelled by carbon emissions will be no easy feat, and will require fundamental changes to nearly all of the goods and services we rely on. However, innovation and economic incentives can make this easier. Technology such as HYBRIT is one way that we can move away from a reliance on fossil fuels, without having to give up necessities like steel. It also represents a push to the entire industry, as other steel producers feel pressured to reduce their own emissions in order to stay competitive. While adding the word ‘green’ to the products and technology we rely on might not result in a more colorful world, the existence of these alternatives makes the transition to a safer, more sustainable economy so much easier.
Works Cited
Allan, B., & Tucker, T. (2021, November 1). Analysis | The E.U.-U.S. Steel Deal could transform the fight against climate change. The Washington Post. Retrieved January 31, 2022, from https://www.washingtonpost.com/politics/2021/10/31/eu-us-steel-deal-could-transform-fight-against-climate-change/
FAQs: The big questions answered. SSAB. (2021b). Retrieved January 31, 2022, from https://www.ssab.com/fossil-free-steel/faqs-the-big-questions-answered
Hoffmann, C., Hoey, M. V., & Zeumer, B. (2021, October 5). Decarbonization Challenge for Steel. McKinsey & Company. Retrieved January 31, 2022, from https://www.mckinsey.com/industries/metals-and-mining/our-insights/decarbonization-challenge-for-steel
Libretexts. (2020, August 25). 23.3: Metallurgy of Iron and Steel. Chemistry LibreTexts. Retrieved December 4, 2021, from https://chem.libretexts.org/Bookshelves/General_Chemistry/Map%3A_General_Chemistry_(Petrucci_et_al.)/23%3A_The_Transition_Elements/23.3%3A_Metallurgy_of_Iron_and_Steel.
SSAB, LKAB & Vattenfall. (2021, February 13). Pilot scale direct reduction with hydrogen. Hybrit. Retrieved December 4, 2021, from https://www.hybritdevelopment.se/en/a-fossil-free-development/direct-reduction-hydrogen-pilotscale/.
SSAB’s fossil-free steel featured in Volvo Group’s vehicle. (2021a, October 13). SSAB. Retrieved January 31, 2022, from https://www.ssab.ca/news/2021/10/ssabs-fossilfree-steel-featured-in-volvo-groups-vehicle.
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Vass, T., Levi, P., Gouy, A., & Mandová, H. (2021). (rep.). Iron and Steel. International Energy Agency. Retrieved January 31, 2022, from https://www.iea.org/reports/iron-and-steel.
Vetter, D. (2021, August 23). How Sweden delivered the world's first fossil fuel-free steel. Forbes. Retrieved January 31, 2022, from https://www.forbes.com/sites/davidrvetter/2021/08/19/how-sweden-delivered-the-worlds-first-fossil-fuel-free-steel/?sh=b388d2b6b553
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