Steel is a foundational material that underpins modern global society, forming the backbone of everything from skyscrapers and bridges to cars and home appliances. Its production, however, has long been a significant environmental liability due to the high temperatures and chemical processes required. Traditional steelmaking is currently responsible for approximately 7% to 9% of global carbon dioxide (CO2) emissions, making the industry a major contributor to climate change. This immense carbon footprint has spurred a technological revolution, driving the development of “fossil free steel.” This innovative product represents a necessary step toward decarbonizing one of the world’s most energy-intensive heavy industries, aiming to maintain the material’s structural importance while drastically reducing its environmental impact.
Defining Fossil Free Steel
Fossil free steel is defined as steel produced without relying on fossil fuels, such as coal, oil, or natural gas, at any stage of the manufacturing process. This definition specifically targets the energy source and the chemical agent used to convert raw iron ore into usable iron. The final product itself is chemically identical to conventionally produced steel, possessing the same strength, durability, and properties.
The primary difference lies in the near-zero carbon footprint associated with its creation, particularly during the initial reduction of iron ore. This low-emission status is achieved by substituting carbon-based inputs with non-fossil alternatives and using fossil-free energy throughout the entire value chain.
The Traditional Challenge: Why Steel Production Emits So Much Carbon
The volume of carbon emissions from the steel industry stems from the conventional production method, which utilizes the Blast Furnace–Basic Oxygen Furnace (BF-BOF) route. This process begins by heating iron ore (iron oxide) in a blast furnace to strip away the oxygen atoms. This chemical stripping, or reduction, is accomplished by using coking coal, a carbon-rich fuel derived from coal.
Coking coal serves a dual purpose: it provides the intense heat necessary for the process, and it acts as the chemical reducing agent. During the reaction, the carbon from the coal bonds with the oxygen in the iron ore, yielding molten iron and releasing massive amounts of CO2 as a byproduct. For every ton of crude steel produced using this traditional method, approximately 1.9 to 2.2 tons of CO2 are released into the atmosphere.
Decarbonizing Production: The Hydrogen Reduction Method
The shift to fossil free steel is primarily achieved by replacing coking coal with green hydrogen (H2) as the reducing agent, a process known as hydrogen-based Direct Reduced Iron (DRI). This technological transformation fundamentally changes the primary chemical reaction in ironmaking.
In the hydrogen reduction method, iron oxide (Fe2O3) reacts with hydrogen gas (3H2) at high temperatures to produce metallic iron (2Fe) and water vapor (3H2O). This substitution eliminates the process-related CO2 emissions entirely, as the only byproduct is water. The resulting metallic iron, known as sponge iron or DRI, is then typically melted down and refined into steel in an Electric Arc Furnace (EAF).
To ensure the entire process remains fossil free, the hydrogen used must be “green hydrogen.” Green hydrogen is produced by using electrolysis, a process that splits water into hydrogen and oxygen using electricity generated exclusively from renewable sources, such as wind or solar power. Furthermore, the Electric Arc Furnace must also be powered by renewable electricity, creating a completely fossil-free value chain from iron ore to finished steel product. This combination of green hydrogen for reduction and renewable electricity for melting allows for emission reductions of up to 95% compared to conventional methods.
Commercial Status and Global Impact
The technology for producing fossil free steel has moved rapidly from the theoretical stage to commercial implementation. The Swedish HYBRIT initiative, a joint venture between steel manufacturer SSAB, mining company LKAB, and energy company Vattenfall, successfully delivered the world’s first fossil free steel in 2021, proving the viability of the hydrogen reduction process at a pilot scale.
Companies like SSAB and H2 Green Steel are now scaling up their operations, with goals to introduce commercial volumes of fossil free steel to the market by the mid-2020s. These efforts involve constructing industrial-scale facilities that integrate hydrogen production and DRI technology. The primary current limitation to widespread adoption remains the infrastructure and high upfront cost associated with producing sufficient quantities of green hydrogen and sourcing reliable renewable electricity.
The development of fossil free steel is playing a role in global decarbonization efforts, particularly in sectors that are difficult to abate. The technology offers nations and industries a direct path to significantly curb industrial emissions, helping major steel-producing countries meet ambitious climate targets. The availability of this low-carbon material is also creating a market for certified green steel, pushing the entire industry toward a more sustainable future.