The modern world has grown around steel bones — everything from tools and home appliances to skyscrapers and airplanes use the versatile material in their construction. But the process of making steel is a significant contributor to global warming and climate change. In 2018, reportedly every ton of steel produced generated 1.85 tons of carbon dioxide, accounting for about 7 percent of global CO2 emissions that year. This poses not just environmental challenges for our ever increasing world, it could also impact steel producers’ bottom line, which is why the industry is developing a “fossil-free” means of making the alloy, one that relies on renewable-sourced hydrogen rather than carbon coke.
Steel is an alloy composed of iron, which in its pure form is relatively soft, with a small amount of introduced carbon, usually about 2 percent of its total weight. This improves the material’s strength and reduces its propensity for fracturing. The process starts by combining iron ore, before coking coal and limestone (which remove impurities) in a blast furnace to create pig iron.
That molten pig iron is then poured into a furnace and high pressure air is introduced via a water-cooled lance. The oxygen chemically reacts with the molten iron to purge impurities — as well as produce significant amounts of carbon monoxide and carbon dioxide. The oxygen also forces impurities like silicates and phosphates present in the pig iron to react with limestone flux, trapping them as waste slag. Today, per the World Steel Association, some 1,864 million metric tons of crude steel are produced annually with China producing a vast majority of it.
While the WSA points out that “in the last 50 years, the steel industry has reduced its energy consumption per tonne of steel produced by 60 percent” and notes that steel is infinitely reusable, and that “new” steel typically contain 30percent recycled steel on average the traditional methods of iron and steel production are becoming untenable — at least if we want to mitigate its impacts on climate change. What’s more, the International Energy Agency estimates that global steel production will grow by a third by 2050, which will only compound the industry’s environmental impacts. That’s where fossil-free steel comes in.
Take HYBRIT (Hydrogen Breakthrough Ironmaking Technology), for example. This process has been developed as a joint venture between three Swedish companies: SSAB, which makes steel, energy company Vattenfall, and LKAB, which mines iron ore. Rather than using coking coal and a blast furnace to convert raw iron ore into metallic iron, the HYBRIT method uses hydrogen generated from renewable energy sources and a technique known as direct reduction, which lowers the amount of oxygen contained within the ore without heating it above the metal’s melting point, to create sponge iron.
Like pig iron, sponge iron is an intermediary material in the steelmaking process (it’ll get shipped off to SSAB to be turned into steel slabs), but in HYBRIT’s case, its production results in the creation of water vapor rather than carbon dioxide.
“The first fossil-free steel in the world is not only a breakthrough for SSAB, it represents proof that it’s possible to make the transition and significantly reduce the global carbon footprint of the steel industry,” Martin Lindqvist, CEO of SSAB, told reporters in August. “We hope that this will inspire others to also want to speed up the green transition.”
The HYBRIT coalition opened a pilot direct reduction plant in Luleå, Sweden last year and has announced plans to increase production to an industrial scale by 2026. The team claims that eliminating fossil fuels from the steelmaking industry in Sweden could drop the country’s total CO2 emissions by at least 10 percent. However, they are not the only group looking into fossil-free steel production. The H2 Green Steel company has announced its intent to open a large-scale plant in northern Sweden by 2024 and expects to produce 5 million tonnes of the material annually by 2030.
In June, Volvo announced that it would be partnering with SSAB to develop fossil-free steel for use in its products — both passenger cars and industrial machines. Last week, Volvo unveiled the first vehicle to be made with fossil-free steel, an 8-plus ton load carrier designed to operate within mines. Not only is the load carrier powered by a fully electric drivetrain, it can autonomously navigate across a worksite as well. Granted only about 3 of the vehicle’s 8 tons were made from fossil-free steel (the drivetrain’s steel components, for example, were made through traditional smelting means), this marks an important first step towards a carbon-neutral transportation future.
“When we have been talking about ‘fossil free’ in the transport sector, we have been focusing a lot on emissions from the vehicles in use. But it's clear to us and to everyone else that we also need to address the carbon footprint from the production of our vehicles,” Volvo Group’s Chief Technology Officer Lars Stenqvist told Forbes. “That's why it's so important now to team up with everyone in the value chain and collaborate in order to drive out all the fossil fuel also used in the production of components, parts and also running our production facilities.”
Volvo expects the autonomous load carriers to enter real-world operation by next year, though the company concedes that its ability to ramp up production of fossil-free vehicles will depend largely on SSAB’s ability to deliver sufficient quantities of the material.
[original story: Engadget]