metallurgy R&D
A surge toward low-or zero-carbon iron and steel production focuses on the use of hydrogen
By Corinna Petry

ydrogen is the most abundant chemical substance in the universe, constituting roughly 75 percent of all matter that humans encounter. Also, hydrogen is a clean fuel that, when consumed in a fuel cell, produces only water. Hydrogen can be produced from a variety of domestic resources, such as natural gas, nuclear power, biomass, and renewable power like solar and wind. These qualities make it an attractive fuel option for transportation and electricity generation applications and, eventually, for industrial-scale metals production.

Hydrogen has become the new buzzword in raw metal manufacturing. Over the past few months, several major global steel producers have joined with energy companies and other partners to plot their way to a decarburized future.

In August 2020, Stockholm-based SSAB, with its partners—iron ore producer LKAB and energy company Vattenfall—started up Hybrit, a pilot plant that manufactures sponge iron.

we have a chance to show that net-zero emissions is possible.
martin lindqvist, ssab
“We aim to be the first to market, in as early as 2026, with fossil-free steel,” Martin Lindqvist, president and CEO of SSAB, announced. “Hybrit technology will enable us to eliminate carbon dioxide emissions in steelmaking and at the same time help our own customers to reduce their climate footprint. We have the chance to revolutionize the entire steel industry and show that net-zero emissions is possible. We must seize this chance,” he said.

The hydrogen will be produced at the pilot plant by electrolyzing water with fossil-free electricity. Tests will be carried out through 2024, first using natural gas and then hydrogen to be able to compare production results.

With Hybrit, SSAB, LKAB and Vattenfall aim to create a completely fossil-free value chain from the mine to finished steel and to introduce a new technology using fossil-free hydrogen instead of coal and coke to reduce the oxygen in iron ore. This means the process will emit ordinary water instead of carbon dioxide.

“The oxygen in the iron is the great challenge and we need to eliminate it,” explained Jan Moström, president and CEO of LKAB. “The pilot plant will play a decisive role before we can ramp up the technology for use on an industrial scale.”

Illustration project
exploring two methods — Salzgitter AG has launched a project called Salcos in order to lower its CO2 emissions beyond the current scope. It is testing new approaches and researching both DRI and blast furnaces process technologies.
Net zero
ArcelorMittal Europe, last June, set out its path to net zero by 2050, and announced pioneering technologies for carbon-neutral steelmaking. Recognizing the need to act now to reduce CO2 emissions, in line with the EU’s Green Deal and the Paris Agreement, the company has invested in two routes to carbon neutrality: Smart Carbon and a route involving direct reduced iron (DRI) manufacturing.

Smart Carbon is a carbon-neutral steelmaking route that leverages all clean energies—circular carbon, clean electricity, and carbon capture and storage (CCS)—within the high temperature-controlled reduction environment of ironmaking. In its first phase, Smart Carbon will primarily use circular carbon (consuming biowaste materials, such as sustainable forestry and agriculture residues, to produce bioenergy).

Reaching carbon-neutral steelmaking via DRI involves using hydrogen rather than natural gas to as the key reducing agent in ironmaking.

“ArcelorMittal Europe is doing a lot of work to develop a path to net zero,” CEO Aditya Mittal said. “Steel should and can play a leading role in achieving the vision for Europe as outlined in the Green Deal.”

The company is building industrial-scale demonstration plants at its operations in Belgium and France. In Hamburg, Germany, ArcelorMittal Europe is planning an industrial-scale project to use hydrogen instead of natural gas to make DRI. “These demonstration plants will allow the company to scale up technologies that will be used in the Smart Carbon and DRI-based routes.”

Some of the technologies should be ready for commercial-scale use by 2025. The estimated investment needed for ArcelorMittal Europe to fully implement Smart Carbon is €15 billion to €25 billion and €30 billion to €40 billion for the DRI-based route. Additional funds would be required for the associated clean energy infrastructure.

Renewable resources
In Germany, Saltzgitter AG recently won federal government funding that will help the company build its first DRI plant to be operated flexibly by hydrogen and natural gas.

Operating this DRI plant will help the steelmaker gain the knowledge to be able to run production with large-scale factories within a few years, CEO Heinz Jörg Fuhrmann said in early December.

The Salzgitter Low CO2Steelmaking technology (Salcos) consists of power generated from renewable sources and harnessed for the production of green hydrogen through electrolysis. In DRI plants, this replaces the carbon used in the conventional blast furnace process for producing iron from ore. Salzgitter Group already installed several wind turbines and hydrogen electrolyzers, and hydrogen production is scheduled for startup during the first half of 2022 (see graphic above).

The full transformation from conventional to hydrogen-based steel production at Salzgitter AG will be implemented in various stages by 2050. This will ultimately reduce the amount of CO2 generated in the production of steel by up to 95 percent, the company stated.

Investment planning
Consultants advise industry to act now
A study by consultancy McKinsey & Co., completed in April 2020, suggests that the future availability of cheap energy from renewables, combined with regulation, will be the key drivers toward the adoption of hydrogen-based steel.

Despite the goal of becoming carbon neutral still being 30 years away for Europe, “it is crucial to act now,” the report’s authors wrote. “Industrial sites have lifetimes exceeding 50 years and investment planning horizons of 10 to 15 years. Asset and footprint decisions need to be made today and must follow a clear decarbonization road map.”

In Europe, green hydrogen-based steel production is likely to become a predominant technology shaping the path to decreasing emissions. “This could entail first optimizing [blast furnace] processes, then switching to EAF using scrap and DRI powered with natural gas or imported HBI.”

Ultimately, companies may adopt carbon-neutral EAF production using a mix of scrap and hydrogen-based DRI. “The DRI method using hydrogen will be key to enabling the production of high-purity steel grades without the emission of carbon dioxide,” the McKinsey study concluded.

Blast furnace application
A different German steelmaker, Saarstahl and Dillinger, is using its existing blast furnaces to make hydrogen-based steels. This company also received federal aid, €14 million, to realize its goals.

“We are ready for the transformation to green steel,” says Tim Hartmann, chairman of Saarstahl and Dillinger.

The new plant in Dillingen, Germany, uses hydrogen as a reducing agent in the blast furnace in normal operation. This is accomplished by injecting hydrogen-rich coke gas. “We can further reduce our carbon emissions on the basis of this technology while gaining important experience in using hydrogen in steel production,” explained Martin Baues, member of the board of directors for technology. “The plant will enable us in the next step to use pure hydrogen in both blast furnaces.”

steel should and can play a leading role in achieving the vision for europe’s green deal.
aditya mittal, arcelormittal
Carbon emissions from the blast furnace can be reduced by replacing the carbon in the blast furnace with hydrogen as a reducing agent and energy source.

Baues notes, however, that the precondition for this development (as well as for the complete conversion of steel production to hydrogen from other technologies such as electric furnaces and hydrogen-based DRI plants) “is the future availability in Saarland [a region of Germany along the French border] of green hydrogen in sufficient quantities and at competitive conditions.”

Hartmann said the company’s goal is to reduce carbon emissions by 40 percent by 2035. Saarstahl and Dillinger have made environment-related investments totaling €70 million over the past three years.

Green hydrogen pact
Major companies in South Korea and Australia are also getting involved in various aspects of carbon reduction. Jeong-Woo Choi, CEO of steelmaker Posco, met in mid-December with Andrew Forrest, chairman of iron ore miner Fortescue Metal Group (FMG) to collaborate on a green hydrogen project using renewable energy. FMG is the world’s fourth-largest iron ore supplier and aims to achieve carbon neutrality by 2040.

Choi credited FMG with being a stable long-term iron ore supplier to Posco and noted, “If competitive green hydrogen can be produced with cooperation between the two companies and is introduced to Korea, the era of green hydrogen in Korea will be accelerated.”

Additionally, both companies agreed to adopt Posco’s premium steel grades for eco-friendly power generation facilities, such as solar and wind power, which are required for producing green hydrogen by FMG. Under the pact, Posco imports FMG’s iron ore to make steel products, which will, in turn, be shipped to FMG’s solar power generation facilities to produce hydrogen.

The United States won’t be left lagging if the Department of Energy’s recent actions are an indicator. In September, researchers at Missouri University of Science and Technology and Colorado School of Mines are using a $4 million DOE grant to prove the economic viability of increased renewable energy usage in steel production.

Sridhar Seetharaman at Mines and Ronald O’Malley at Missouri S&T plan to create a steel production system that combines a hydrogen-reduction reactor for ironmaking (H2DR) with electric furnace melting for steelmaking. This combination would then be integrated into a flexible electrical grid with energy storage and hydrogen generation by balancing hydrogen and natural gas usage in the H2DR process.

Illustration of a Factory
Equipment maker steps forward
The Centro Combustion R&D team at Danieli & C. S.p.A., Buttrio, Italy, has developed a new hydrogen multi-air burner, which it calls Hydro Mab, as the answer for burning a natural gas/hydrogen mixture that results in CO2 reduction.
Through recent decades, CO2 emissions have been reduced by increasing thermal efficiency, according to the designer, engineer and builder of iron, steel and aluminum production equipment. However, “the use of hydrogen in combustion processes could bring the steel industry towards full decarbonization,” the company states.

Computer modeling simulations and laboratory tests led Danieli’s Centro Combustion R&D team to developing Hydro Mab. In addition to CO2 reduction, Hydro Mab burners maintain the lowest levels of nitrogen oxides emissions and the optimal flame pattern.

O’Malley and Seetharaman, who is associate vice president of research and professor of metallurgical and materials engineering at Mines, believe that the increased integration of electric power for steelmaking using electrolysis will help balance the electrical grid and reduce carbon dioxide emissions.

“The integration of this H2DR combination into the U.S. supply chain would be a proof-of-concept that the steel industry is ready for decarbonization,” says O’Malley, the F. Kenneth Iverson Endowed Chair of Steelmaking Technologies and director of the Kent D. Peaslee Steel Manufacturing Research Center at Missouri S&T.

Decarbonization of the steel industry can be achieved by connecting ironmaking to renewable electric power through electrolytically produced hydrogen, the team proposes.

“While the use of hydrogen to produce iron from ore is proven, the impact of dynamically rebalanced reducing gas mixtures in the H2DR process on the steelmaking must be assessed,” says O’Malley. “This requires a closure of several knowledge gaps in ironmaking and EAF steelmaking.”

Partnering on the DOE grant are Steel Dynamics Inc., Gerdau Special Steel North America, Nucor Corp., Voestalpine Texas LLC, Danieli Corp., Praxair Inc. and Air Liquide.