In the last 15 months, SMS was awarded two green steel lighthouse projects based on direct reduction. By the middle of thisdecade, both H2 GreenSteel in Sweden and Germany-based thyssenkrupp Steel will prove that a massive decrease in CO2 emissions by up to 95% is possible. There is no question that conventional blast furnace ironmaking must be tackled, as greenhouse gas emissions are primarily attributed to this process. However, is direct reduction the only technology on the pathway towards carbon-neutral iron production?
One constraint of conventional direct reduction shaft furnace is the availability of high-grade iron ore. Today, iron ore in the form of pellets or lump ore as required for direct reduction, represents less than 25% of the global market share. Moreover, current forecasts see a 50% gap between supply and demand of high-grade iron ore by 2050. Second, the economic feasibility of widespread green hydrogen adoption remains challenging, given the scale required to meet global steel demand. The availability of decarbonized electricity make ubiquitous green hydrogen production implausible. Thus ammonia has become a rising star for the future green hydrogen supply chain as a cheap hydrogen carrier.
Furthermore, electricity consumption emerges as a significant factor, given the imperative to more than double renewable energy generation by 2050 to attain net-zero targets. A staggering two-thirds of worldwide existing renewable generation capacity (approximately 2,000 GW) would be earmarked for the steel industry. Last, but not least, transition speed is also important. Limitations on plant builder capacities and funding opportunities present significant challenges.
Given all these constraints, the World Steel Association projects that steel production based on direct reduction shaft furnace will see an over fourfold increase until 2050. In return, this means that conventional BF-BOF production routes will continue to play a pivotal role, also because of population growth and increasing per capita steel consumption.
The transformative solution for greening conventional ironmaking is the Paul Wurth EASyMelt, short for electrically assisted syngas smelter. The EASyMelt is a resource-flexible, crisis-resistant, and cost efficient alternative to direct reduction shaft furnace. It offers much lower investment and operational costs compared to conventional direct reduction plants. Plus, it can be integrated into existing integrated steel plants, demonstrating a significant pathway for the decarbonization of existing blast furnaces worldwide.
The five-step EASyMelt approach
- Injection of reducing gas via shaft: The initial phase involves the injection of syngas (reducing gas) at 950°C into the existing blast furnace at shaft level, creating the conditions for iron ore direct reduction. This syngas can be generated through optimized steelmaking methods such as SMS group’s novel dry reforming hot stoves, or through more conventional techniques like catalytic methane reforming or catalytic partial oxidation of natural gas.
- Production of reducing gas: The syngas stoves produce syngas (H2 + CO) from methane and CO2, using a non-catalytic dry reforming reaction in a cyclic operation. Dry reforming allows for internal CO2 recycling in the EASyMelt system, by chemically upgrading CO2 to CO with the help of methane from coke oven gas or natural gas.
- Injection of reducing gas via tuyeres: Syngas is introduced at the tuyere level. This innovative approach diverges from traditional methods, offering technical ingenuity and flexibility to incorporate hydrogen into the reducing gas composition. Hydrogen utilization is highly efficient in this context, as the very high temperatures unattainable from conventional heating methods allow for a large percentage of the hydrogen to reduce iron ore very quickly.
- Plasma-based tuyere-level superheating: A plasma-based superheating system is implemented at the tuyere level, effectively elevating the injection syngas temperature between 1,700°C to 2,200°C. This electrifies the ironmaking process and has undergone successful previous trials.
- Carbon capture integration: The final phase revolves around carbon capture. Any remaining emissions are systematically captured for storage or utilization, ensuring complete climate neutrality. A notable synergy arises from the enriched CO2 stream produced by the syngas dry reformers, aligning seamlessly with carbon capture objectives. Additionally, processes like sorption-enhanced water gas shift (SEWGS) are viable options for decarbonizing the residual top gas.
MoU with Tata Steel
In June 2023, SMS group signed an agreement with Tata Steel India to advance and demonstrate this groundbreaking technology on an industrial scale. Both companies are steadfast in pursuing climate neutrality in steel production. “Tata Steel is actively looking for solutions to facilitate the transition to green steel production, and thus contribute to a sustainable future. Further, as the second largest steel producer in the world, India also places huge responsibility on large manufacturers like Tata Steel to lead the country’s decarbonization journey,” says Tata Steel India’s CEO and Managing Director, T. V. Narendran. “We are delighted to reaffirm our partnership with SMS group and intend to take this association ahead with deeper collaboration to access better technologies and processes that meaningfully and consistently reduce our carbon footprint.”
By implementing EASyMelt, Tata Steel aims to cut CO2 emissions by over 50% compared to baseline operations showcasing the industry’s drive toward sustainable steel production. This collaborative agreement marks the potential start of a revolutionary shift, presenting a viable and forward-thinking combination of direct reduction and smelting for direct-reduction based steel production. Thomas Hansmann, CTO of SMS group, is proud of the companies’ joint commitment: “This will represent a significant milestone for the decarbonization of existing blast furnace plants worldwide. As the first example of its kind, introducing EASyMelt on an industrial scale will pave the way for future projects, showing how the green transformation can be implemented using existing plants.”