In the cityA group of engineers and scientists inspected a stack of brick-sized, gunmetal gray steel ingots in Woburn, Massachusetts. They were located on a desk in a neon-illuminated laboratory space.
They were looking at a steel batch that was created using an innovative manufacturing technique. Boston MetalA company spun out of MIT ten years ago, aims to revolutionize the way the alloy has been made over the centuries. By using electricity to separate iron from its ore, the firm claims it can make steel without releasing carbon dioxide, offering a path to cleaning up one of the world’s worst industries for greenhouse gas emissions.
Steel is an essential input in engineering and construction. It is also one of the most widely used industrial materials around the globe. 2 billion tons produced annually. However, this abundance comes at a high price for the environment. Steelmaking is responsible for 7 to 11% of global greenhouse-gas emissions, making it one of the largest industrial sources of atmospheric pollution. Production could also be a problem. The rise by a third by 2050, this environmental burden could grow.
This is a major challenge when it comes to tackling the climate crisis. The United Nations Says significantly cutting industrial carbon emissions is essential to keeping global warming under the 1.5 degrees Celsius mark set under the 2015 Paris climate agreement. To achieve this, the emissions from steel and other heavy industry must fall by 93 per cent by 2050 according to the UN climate report. Estimates by the International Energy Agency.
Facing escalating pressure from governments and investors to reduce emissions, a number of steelmakers—including both major producers and startups—are experimenting with low-carbon technologies that use hydrogen or electricity instead of traditional carbon-intensive manufacturing. Some of these initiatives are close to becoming commercially viable.
“What we are talking about is a capital-intensive, risk-averse industry where disruption is extremely rare,” said Chris Bataille, an energy economist at IDDRI, a Paris-based research think tank. Therefore, he added, “it’s exciting” that there’s so much going on all at once.
Experts agree that it is possible to transform an industry that has been dominated by the United States. $2.5 Trillion in 2017 and employs more than six million people will take enormous effort. Beyond the practical obstacles to scaling up novel processes in time to reach global climate goals, there are concerns about China, where over half the world’s steel is made and whose plans to decarbonize the steel sector remain vague.
“It’s certainly not an easy fix to decarbonize an industry like this,” said Bataille. “But there’s no choice. The future of the sector—and that of our climate—depends on just that.”
Modern steelmaking includesThere are many production stages. Iron ore is most commonly crushed and made into sinter (a hard solid) or pellets. Coke is also made from coal. The coke and ore are then mixed with limestone, and fed into a blast furnace where an extremely hot air stream is introduced from below. At high temperatures, the coke ignites and forms liquid iron, which is also known as blast furnace iron or pig iron. The molten material then goes into an oxygen furnace, where it’s blasted with pure oxygen through a water-cooled lance, which forces off carbon to leave crude steel as a final product.
This method, first invented by Henry Bessemer, an English engineer in the 1850s to produce carbon-dioxide omissions in different ways. The chemical reactions in blast furnace produce emissions. First, carbon trapped in limestone or coke binds to oxygen in the air to make carbon dioxide. To heat the blast furnace, to power sintering, pelletizing, and coke ovens, fossil fuels are also used. This produces carbon dioxide.
As high as 70% of the world’s steel is produced this way, generating Nearly two tons carbon dioxide for each ton of steel produced. The Rest 30% is almost all made through electric arc furnaces, which use an electrical current to melt steel—largely recycled scrap—and have far lower CO2 emissions than blast furnaces.
However, the limited scrap supply means that future demand cannot be met in this manner, according to Jeffrey Rissman who is a program director for the industry and head of modeling at Energy Innovation, a San Francisco-based energy policy and climate policy firm. He said that recycling could supply up 45 percent of the global demand by 2050 if there are the right policies. “The rest will be satisfied by forging primary ore-based steel, which is where most emissions come from.”
So “if the steel industry is serious” about its climate commitments, he added, “it will have to fundamentally reshape the way the material is made—and do so fairly quickly.”
Another alternative technologybeing tested replaces coke and hydrogen. Sweden Hybrit—a joint venture between the steelmaker SSAB, the energy supplier Vattenfall, and LKAB, an iron ore producer—is piloting a process that aims to repurpose an existing system called direct reduced iron. The coke from fossil fuels is used to extract oxygen from iron ore pellets. This creates a porous iron pellet called “sponge iron”.
Instead, the Hybrit method extracts oxygen using fossil-free hydrogen gas. The gas is created through electrolysis, a technique that uses an electric current—in this case, from a fossil-free energy source—to separate water into hydrogen and oxygen. (Pure hydrogen today is made with methane, which produces CO2 when burned.) The resulting sponge iron then goes into an electric arc furnace, where it’s eventually refined into steel. The process does not produce any water vapor.
“This technology has been known for a while, but it’s only been done in the lab so far,” said Mikael Nordlander, head of industry decarbonization at Vattenfall. “What we are doing here is to see if it can work at [the] industrial level.”
Hybrit’s first milepost was reached last August by SSAB. This company produces and sells the final product. The first batch of fossil-free Steel was delivered to the automaker Volvo, It was used in vehicle prototypes. It also plans to build a plant for commercial production. This is expected to be completed by 2026.
H2 Green Steel, a Swedish company, is also developing a similar commercial-scale hydrogen-steel plant. It has raised $105 million from private investors, companies like Scania and Mercedes-Benz and the IMAS Foundation, which is closely linked to Ikea. The company Plans to begin production by 2024 and produce 5 million tons of zero-emissions steel annually by the end of the decade. Other companies that are testing hydrogen-powered steelmaking include ArcelorMittal, Thyssenkrupp, Salzgitter AG in Germany; Posco in South Korea; and Voestalpine in Austria.
The use of electricity can also be used for iron ore reduction. The iron is then mixed together with carbon and other ingredients.
“What we do is basically swapping carbon for electricity as a reducing agent,” explained Adam Rauwerdink, the company’s senior vice president of business development. “This allows us to make very high-quality steel using way less energy and in fewer steps than conventional steelmaking.” As long as power comes from fossil-free sources, he added, the process generates no carbon emissions.
He stated that the company currently has three pilot lines at its Woburn facility and is working to bring its laboratory concept on the market. $50 Million raised last year from an investor group including Breakthrough Energy Ventures, backed by Bill Gates, and the German carmaker BMW. A demonstration plant of commercial scale is expected to be operational by 2025.
“I feel all these solutions have their place, depending on location, resource availability, and targeted product,” said Sridhar Seetharaman, a professor of materials science and engineering at Arizona State University. “However I do not think for now any one alone will give you a silver bullet to meet the demand.”
“Hydrogen has a bit of a head start being based on an established system and it’s also ahead in commercialization,” said Bataille, the IDDRI energy economist. “But achieving a net-zero steel industry will take more carbon-free pathways, so I think there will be enough room in the market for all of them in the end.”
Steelmaking is more environmentally friendlyWhile these processes are showing signs of momentum, there are still many serious challenges to face. Thomas Koch Blank, senior principal at a Colorado-based nonprofit, stated that while there are many challenges to overcome, the most important is the huge expansion of renewable energy infrastructure required for an industry-wide shift towards these new methods. Rocky Mountain Institute. He estimates that the world could use up to three times the amount of solar and wind energy currently in place to electrify its primary steel production.
Another barrier is the cost. It would take a lot of capital to switch to hydrogen or electricity. Koch Blank noted that the cost of clean hydrogen will increase because steel producers are close to low-cost coal rather than low price hydrogen. “These upfront costs will likely drive up the price of both steel and the end products, at least in the beginning.”
Rissman, an analyst in San Francisco, believes that legislation on both the supply side and the demand side could help offset higher costs and encourage greater investment in greener technologies. He suggested that governments could encourage the use of low carbon steel for building and infrastructure by mandating that state-funded projects use low-carbon construction materials. They could also make it more expensive for countries with stricter emissions regulations to purchase from them. That will help domestic producers “stay competitive” as the market for clean steel “grows and new production processes achieve economies of scale,” said Rissman.
China is perhaps the biggest roadblock. Around 90% of steel production is achieved using blast furnaces. President Xi Jinping will be inaugurated in September 2020. Announcement that the country aims to become carbon neutral by 2060. To reduce pollution from domestic steel mills, the country has adopted these measures. About 15% of the nation’s overall carbon emissions, Beijing has also pledged to Peak steel emissions by 2030. Despite this, China announced 18 new blast furnace projects in the first six months 2021. According to the Helsinki-based research group Center for Research on Energy and Clean Air.
Rissman stated that steel is one the most difficult industries to decarbonize. Global coordination would be greatly helpful.
Back in Boston, Rauwerdink, surveying Boston Metal’s factory lines, agreed. “It’s a fantastic challenge that we’re up against,” he said. But, he added, “We are showing that solutions exist—and work.”
Marcello Rossi is an independent journalist working in science and the environment. He is based out of Milan, Italy. His work has been published among others by Al Jazeera and Smithsonian, Reuters and Wired.