Numerous leading steelmakers have pledged in recent months to reduce their carbon emissions to net-zero by 2050 or sooner. This is despite steelmaking being one of the toughest industries to decarbonise and contributing 7-9pc to global emissions.

The list includes Arcelormittal, the world’s largest steel manufacturer, and Thyssenkrupp, Nippon Steel and Posco, the largest steel manufacturers in Germany, Japan and South Korea respectively.

About three-quarters of global steel is manufactured in blast oxygen furnaces (BOF), requiring temperatures of 1,200°C and generally using coal. BOF-manufactured steel accounts for 90pc of industry emissions on a global basis.

“The transformation to climate-neutral steel will only succeed if the framework conditions are right” Thyssenkrupp

The rest is made in electric arc furnaces (EAF) at around 400°C. These tend to be found in places where the natural gas to fire them is cheap, such as the Middle East and US. It is important to note that EAF can only produce steel from scrap metal or direct reduction iron (DRI), the latter produced through an additional industrial process.

The two steelmakers that stand out as the most likely to achieve their emission commitments—and potentially provide cutting edge technologies to other steelmakers in the industry—are Thyssenkrupp and Sweden’s largest steelmaker, SSAB. The latter is part of the Hybrit consortium with LKAB and Vattenfall, Europe’s largest iron ore producer and Sweden’s largest utility respectively.

SSAB and HYBRIT

The goal of the Hybrit consortium, formed in 2016, is a ‘full decarbonisation’ approach for the manufacture of steel. To achieve this aim, it is following the proven DRI/EAF route, but its goal is to use green hydrogen produced from solar, wind or water instead of natural gas. The consortium commissioned the world’s first pilot plant to produce ‘fossil-free’ steel at SSAB’s Lulea plant in Sweden in September.

“The pilot trial programme is going according to plan,” Amelie Winberg, a spokesperson for SSAB, tells Hydrogen Economist. “Our time plan remains [that] we aim to have fossil-free steel on the market in 2026.”

SSAB is planning to break ground on a large-scale Hybrit plant in 2023 and, in conjunction with the conversion of the blast furnaces at Oxelosund, Sweden to EAF in 2025, slash its Swedish emissions by a quarter. By doing the same to blast furnaces in Lulea, Sweden and Raahe, Finland between 2030 and 2040, SSAB is planning to eliminate most of its remaining emissions. The company’s goal is to be free of fossil fuels by 2045.

Thyssenkrupp Steel

By contrast, Thyssenkrupp is pursuing a two-prong strategy to become climate-neutral by 2050, so-called carbon direct avoidance (CDA) and carbon capture and usage (CCU). CDA includes an approach similar to Hybrit, with the company targeting 2024 for its first large-scale direct reduction (DR) plant, as well as replacing pulverised coal in blast furnaces with hydrogen to reduce CO₂ emissions by up to 20pc. The company was the first in the world to inject hydrogen into a blast furnace at its Duisburg plant in November 2019.

In addition, Thyssenkrupp is planning to simply upgrade the DRI in a traditional blast furnace—rather than an EAF—until 2026, at which point it will replace this step by combining the DR plant with an ‘innovative melting unit’ powered by green electricity.

1,200°C – Temperature required by blast oxygen furnaces

“This will create a ‘blast furnace 2.0’ from the DR plant and melter, producing an ‘electric pig iron’ and completely replacing a first conventional blast furnace,” Thyssenkrupp tells Hydrogen Economist in a statement.

A key advantage of the two-prong strategy is it achieves both climate-neutrality in the long term and significant emission reductions in the shorter term. For example, Thyssenkrupp is targeting the production of 50,000t/yr of climate-neutral steel by 2022 through a combination of hydrogen use in a blast furnace and CCU. The company was also the first in the world to produce ammonia and methanol from steel mill gases. Thyssenkrupp is aiming to slash emissions by 30pc between 2018 and 2030, despite its plants being “close to their theoretical optimum”.

“However, the transformation to climate-neutral steel will only succeed if the framework conditions are right,” says Thyssenkrupp. “We need the appropriate infrastructure and regulatory framework for the network. This is where politics is needed. We also need to establish a hydrogen market in a very short time.”

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Author: Vincent Lauerman