The race to cut emissions

Leading the way to make the steel industry more sustainable

Thanks to its technological assets, Tenova is landing new contracts with steel manufacturers seeking to reduce carbon dioxide emissions by replacing fossil fuels with green hydrogen to make direct reduced iron (DRI) and reduce dependency on coke-fired Blast Furnaces.

#8-August 2023

Tenova has recently won several new contracts, including one for supplying a direct reduction (DR) plant for the German steelmaker Salzgitter and one for a very large electric arc furnace (EAF) for the Korean steelmaker POSCO. These contracts are united by the common goal of investing in technologies that can significantly cut greenhouse gas emissions – an increasingly urgent objective for safeguarding our planet.

"DRI is gaining momentum because it is currently the most efficient solution on the market capable of transforming the traditional integral cycle to a process with low CO2 emissions," said Mario Marcozzi, Tenova's Marketing and Sales Director. "DRI is a system that allows processing iron oxide pellets into an iron source that can be charged in either an electric arc furnace to produce steel or a submerged arc furnace to produce hot metal."

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ENERGIRON® is an innovative DR Technology jointly developed by Tenova and Danieli, resulting in significant emissions mitigation. Integral cycle plants based on DR produce 50% less CO2 than traditional blast furnace routes, even when operating on natural gas alone.

Additionally, the CO2 absorption units integral to the ENERGIRON® reactors capture about 250 kg of CO2 out of the 400 kilograms of CO2 per ton of steel produced during the process. "With the ENERGIRON® scheme, we recirculate process gas and capture the CO2 that results from the reduction of iron oxide to metal," Marcozzi remarked. "This way, most of the CO2 is captured. Some ENERGIRON® users already sell this captured CO2 to industries that can use it, such as producers of carbonated beverages, or pump the gas into depleted oil fields to boost the extraction of the residual oil."

Germany's Salzgitter has ordered a new DR plant from Tenova to accelerate its transition to low-carbon steelmaking. The plant will produce more than 2 million tons of DRI per year, with the possibility to freely adjust the mix of hydrogen and natural gas in the feed depending on costs and operating conditions. The project's first stage, scheduled to begin by the end of 2025, consists of the DR plant, an EAF, and a 100 MW electrolyzer for hydrogen production. By the end of 2033, the transformation of steel production at the Salzgitter site will be complete, allowing the company to produce virtually CO2-free steel.

Marcozzi highlighted the advantages that Tenova's DRI technology brings to integrated cycle steelmakers: "By pairing DR with a reducing electric furnace, like our iBlue process, the steelmaker can mimic in full the operation of a Blast Furnace and produce Hot Metal, retaining all the downstream process and product quality, while, crucially, cutting the environmental impact by a large percentage."

One of the most prominent features of the ENERGIRON® reactors is that they can operate with any mix of natural gas and hydrogen, enabling a gradual transition as hydrogen supplies will become more reliable and affordable. The mix can be freely adjusted to trim the DRI pellets' chemical composition depending on the downstream process's needs.

"It can work from 100% natural gas to 100% hydrogen," Marcozzi explained. "The module at SALCOS will initially operate with natural gas, but it is primed for the eventual switch to hydrogen as soon as the conditions allow it. Everybody talks about green hydrogen; nonetheless, the industrial solutions to satisfy the expected demand at affordable costs are yet to be fully developed. While we foresee this will take several more years, this should not be a reason to delay the shift to a cleaner, less impacting ironmaking route that is hydrogen-ready and industrially proven."

"We have created the right product at the right time," he underscored. "We have a zero reformer system, which means that we don't need an additional station to reform the gas because we do it directly in the reactor. And this, together with the fact that ENERGIRON® modules operate at high pressure, is why our modules can use every fuel."

Indeed, Tenova is also the supplier of the hydrogen-ready technology used by China's HBZX High Tech, part of Hebei Iron & Steel Group. HBZX can now produce DRI using coke oven gas with more than 60% hydrogen content. According to the International Energy Agency, this will reduce CO2 emissions to as low as 125 kg of steel produced, just a fraction of the global average of 1,400 kilograms per ton of steel.

HBZX's plant is the world's first hydrogen-enriched, gas-powered DRI industrial production facility – and the greenest. This achievement sets a clear path for transitioning from the carbon-based primary furnace route for steel production to gas-based DRI technology and electric steelmaking.

Tenova recently received an order from POSCO, the South Korean steelmaker gradually converting from the BF-BOF route towards Electric Steelmaking based on EAF. "This innovative EAF will tap 280 tons of liquid steel and is the newest from a series of record-breaking furnaces made by Tenova worldwide. These are the most productive units in both scrap-based and DRI-based categories globally. In POSCO's case, this new EAF will be equipped with our continuous scrap charging system and an electromagnetic stirring system to produce the electric steel grades needed by the electrical mobility and green power generation industries, amongst other things," Marcozzi said.

"Still, there are several challenges to the transition to green steel. First, the scarcity of suitable raw materials to feed the EAFs, such as scrap with low residuals or DR-grade pellets.

To address the issue of the high-grade pellets, we have developed the iBlue process, allowing BF-grade pellets with high contents of acidic gangue, whose use in an EAF would result in high energy consumption and loss of yield."

Marcozzi underlined he expects more steelmakers to turn to these new technologies as they transition to green production: "CO2 emission reduction is one of the main drivers for any decision in steel manufacturing technology. We expect it will not take long for the cost of CO2 emissions to become so high to make it untenable to produce steel the traditional, carbon-intensive way. At Tenova, we are fully prepared to take this challenge head-on – we are proud to lead the way in green steelmaking at such a critical historical time."