SALCOS® - We turn steel green

With SALCOS® (Salzgitter Low CO2 Steelmaking), we have joined forces with partners from industry and research to lay the foundations for virtually CO2-free steel production. Central elements of the concept are electricity from renewable sources and its use in the production of hydrogen by means of electrolysis. This green hydrogen will replace the coal we currently use in the conventional blast furnace process. This will be possible with the help of so-called direct reduction plants, in which iron ore is reduced to iron directly in the solid state by hydrogen. This technology emits water vapor instead of CO2.

Our SALCOS® climate initiative thus pursues the Carbon Direct Avoidance approach, which stands for avoiding the generation of CO2 in steel production from the outset. Overall, our approach enables us to reduce CO2 emissions in steel production by over 95%.

How can hydrogen reduce CO2 emissions in steel production?

We currently produce pig iron by using coal in our blast furnaces. This releases CO2 as a result of the process. In direct reduction, on the other hand, iron ore is reduced with the aid of hydrogen. The hydrogen reacts with the oxygen in the iron ore (iron oxide) directly in the solid state and converts it into sponge iron (almost pure iron). Instead of CO2, this technology produces water (H2O), which in turn is reused in the integrated process. In order to be able to process sponge iron further, the porous material is finally melted down together with steel scrap in an electric arc furnace.

Our SALCOS® technology concept envisages the gradual replacement of our blast furnaces with direct reduction plants. The first of these plants could go into operation in 2026.

Previous: Classic blast furnace

Future: Direct reduction


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WKA Aufbau

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PEM Elektrolyse

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How do we produce green hydrogen?

Hydrogen can be produced by means of electrolysis. In this chemical reaction, water is split into its components hydrogen and oxygen by means of electricity. It is beyond doubt for us that the electricity required for this must come from renewable energies such as wind power. For the production of green hydrogen, we erected seven wind turbines on our Group premises in Salzgitter under the project name "WindH2 - Wind Hydrogen Salzgitter", together with Avacon Natur GmbH. The green electricity generated by these plants is used to produce green hydrogen by means of PEM electrolysis.

Another electrolysis is being operated as part of the GrInHy2.0 project. The high-temperature electrolyzer is the largest of its kind in the world and operates highly efficiently. Unlike PEM electrolysis, the GrInHy2.0 electrolyzer uses steam from industrial waste heat from steel production. Both plants can cover today's hydrogen demand for annealing processes and for steel refining, thus displacing gray hydrogen generated from natural gas from our production. However, the quantity required for this is only a fraction of the hydrogen needed for SALCOS® implementation.

To the project WindH2To the project GrInHy2.0

Focusing on the future - Our successes

SALCOS® is a comprehensive project in various sub-steps. During our transformation process, we are celebrating many smaller and larger successes. In the Salzgitter Holding press releases, we keep you up to date on all current developments relating to SALCOS®.

01.11.21 | Article of Salzgitter Flachstahl GmbH

Low carbon steel for Arania

ARANIA, a manufacturer of high and low carbon precision cold rolled strip and micro-alloyed steels, uses Salzgitter's hot rolled material to reduce its carbon footprint.

21.10.21 | Press release of Salzgitter AG

Miele opts for green steel from Salzgitter AG

Gütersloh/Salzgitter – The Miele Group, one of the world’s leading manufacturers of premium household appliances, has opted for Salzgitter AG’s green steel in its drive to reduce its CO2

20.10.21 | Message of the Salzgitter AG

Salzgitter Group at Blechexpo Trade Fair: focus on low CO2 steel

Salzgitter/Stuttgart – The Salzgitter Group will be represented by several subsidiaries at this year’s Blechexpo 2021 that will be taking place from October 26 through to 29,…

04.08.21 | Press release of Salzgitter AG

Salzgitter AG and Anglo American cooperate in optimizing iron ore supplies for low CO2 steel production

Salzgitter AG’s subsidiary Salzgitter Flachstahl GmbH has signed a Memorandum of Understanding (MOU) with Anglo American to join forces…

until 2045

Full SALCOS® conversion: CO2 reduction greater than 95%

from 2030

Second SALCOS® expansion stage: 50% reduction in CO2 emissions


First SALCOS® expansion stage: CO2 reduction of 30%


Commissioning of first direct reduction plant flexibly operated with hydrogen and natural gas


Commissioning WindH2 electrolysis


Commissioning of world's largest high-temperature electrolysis (GrInHy2.0)


Commissioning "Windpark Salzgitter" (30 MW)


Start of SALCOS® accompanying research (BeWiSe, MACOR follow-up project)


Start GrInHy2.0


Start SALCOS® Feasibility Study (MACOR)


Start of research project GrInHy


Project start SALCOS®

SALCOS®- First steps

SALCOS® comprises three central building blocks and is accompanied by various research projects. From hydrogen generation and sector coupling to iron ore direct reduction, we are working with various specialists. The concept is supported by extensive studies on technical and economic feasibility, which are used to define the necessary framework conditions and schedule the next steps.

Project stage 01 │ Sector coupling of renewable energies
01 │ Sector coupling of renewable energies

WindH2 - Green power from wind energy

The "Windpark Salzgitter" was built by our partner Avacon as part of the WindH2 project. It consists of seven wind turbines of the firm Vestas with a hub height of 169 meters. A total output of around 30 MW enables us to generate green electricity from wind power. Our PEM electrolysis produces green hydrogen in parallel operation with the high-temperature electrolyzer.

Project stage 03 │ Iron Ore Direct Reduction
03 │ Iron Ore Direct Reduction

µDRAL - Step-by-step conversion to direct reduction plants

The first iron ore direct reduction plant (DRI plant) to operate flexibly with hydrogen and natural gas is being developed and installed by our partner Tenova. As soon as we can replace one of our blast furnaces with such a plant, which will then be correspondingly larger, we will reduce our current CO2 emissions by around 30%. By 2050 we want to have replaced all our blast furnaces and thus save over 95% of today's CO2 emissions.

Project stage 02 │ Hydrogen production
02 │ Hydrogen production

GrInHy2.0 - Green hydrogen through electrolysis

As part of the GrInHy2.0 project, together with our partners Sunfire and Paul Wurth we built the world's most powerful high-temperature electrolyzer on our site. Using electricity from renewable energies and steam from waste heat from steel production, 200 Nm³ of green hydrogen per hour can be produced with high electrical efficiency.

Project stage 04 │ Research & Studies
04 │ Research & Studies

BeWiSe – SALCOS® Accompanying Research

The MACOR feasibility study confirmed the technical feasibility and advantages of our SALCOS® approach. In the follow-up project BeWiSe (accompanying research into hydrogen in steel production), the proven team from the Fraunhofer Gesellschaft and the Salzgitter Group is dedicated to the technical, economic and ecological optimization of the SALCOS® concept.

Press commentary on SALCOS®

With the launch of the SALCOS® project and the resulting pioneering position in the industry, we are also attracting a great deal of public attention. We are pleased about the growing interest in Carbon Direct Avoidance and the fact that other steel producers are also increasingly considering this approach.



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Volker Hille’s passion project could cut Germany’s entire CO2 output by almost one percent. He is head of corporate technology at Salzgitter Group ...

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We make the difference - for the environment

You may not be able to see the difference, but it will make a big difference to our environment. While our products will remain of the usual, highest quality with the switch to low-CO2 production, our emissions will be significantly reduced. We have a clear target in mind: 95% less CO2 emissions in steel production.

Our products for a sustainable future

Pipes for the transport and storage of hydrogen

As a specialist in all aspects of the pipe product, Mannesmann Line Pipe GmbH regularly develops new applications and customer-oriented solutions.

Mannesmann Line Pipe GmbH is in close contact with national and international institutes - in particular the Group's own research institute Salzgitter Mannesmann Forschung GmbH, but also with various Fraunhofer institutes and universities. Mannesmann Line Pipe GmbH regularly plays a leading role in the development of national and international standardization of pipe production, supply and application.

Research and innovation have top priority at Mannesmann Line Pipe GmbH. In this way, the company secures a leading market position in terms of product quality, the possible applications of steel pipes, process and production technology as well as application-related customer requirements.

Specially developed and qualified for the transport of hydrogen, the mechanical-technological properties of the steel pipes exceed the requirements of the EIGA directive and guarantee optimum safety and service life.

Green flat steel with less than a quarter of the previous carbon footprint

Salzgitter AG offers its customers green flat steel in a differentiated range of dimensions and grades. The company is thus responding to the lively interest in such materials.

The CO2 footprint of these products will be less than a quarter of what it was before. To make this possible, one of the two continuous casters at the Peine steel mill will be equipped to cast slabs.

For understandable technological reasons, high-quality flat steel products are the domain of integrated steel mills. Our pioneering SALCOS® project is aimed at gradually converting them to low-CO2, hydrogen-based metallurgy.

A further milestone on this path will be marked in a few months' time with the first green flat steel.

For a large number of Salzgitter Flachstahl customers, it is important to obtain a product that is physically real and not merely CO2-reduced on the basis of more or less theoretical balance sheet considerations.

Our research for a sustainable future

Hydrogen: for sure!

Hydrogen is an important element in the success of the energy transition. Along the entire value chain, Salzgitter Mannesmann Forschung GmbH is involved in joint projects on safe hydrogen infrastructure, production and hydrogen-based steel production.

For decades, Mannesmann Forschung has been focusing on hydrogen-affected corrosion, both under the influence of sour gas and in the medium of pressurized hydrogen, experimental and computational component testing with destructive and non-destructive tests taking account of use.

These activities relate in particular to the use of steel tubes in the hydrogen industry, e.g. for transport lines, storage tanks and vessels in the infrastructure sector as well as for supply lines and tanks in the mobile applications sector.

For the future, Mannesmann Forschung is planning innovative expansion of the laboratories with a focus on investigations and tests on steel surfaces, material integrity and applications in the field of compressed hydrogen gas and other hydrogen storage media.

We are making a strong case for green hydrogen

Not only we, but also our entire economy can become more sustainable with the help of hydrogen. That's why we are involved in various projects to build a green hydrogen economy and promote hydrogen-based technologies.

Logo HySteel


The members of the HySteel Expert Commission are jointly pursuing the goal of developing a forward-looking strategy for low-emission, hydrogen-based steel production in 2050 for Germany.



H2Global is a support scheme to achieve the goals adopted in the National Hydrogen Strategy (NWS) related to green hydrogen (H2) production and import.

Logo GET H2


To establish the core for a nationwide hydrogen infrastructure to make efficient implementation of the energy transition possible: That is the goal of the GET H2 initiative.

The framework conditions for our transformation

With SALCOS, we have deliberately opted for a so-called "Carbon Direct Avoidance (CDA)" strategy that avoids the generation of CO2. With this project, we are taking a pioneering position in the industry. The associated challenges are extensive and the hurdles primarily economic in nature. The cost of natural gas, hydrogen and renewable energy is significantly higher than that of the coal used today, and so we are dependent on an appropriate political framework to remain competitive.



In order to finance the technologies required for SALCOS® and offset the higher operating costs, suitable regulatory framework conditions would have to be created. However, as an international company operating on the world market, it is not possible to pass on the increased costs to the product because the price pressure is immense. In other countries, steel is produced more cheaply, but with more emissions and in compliance with lower standards.

Integration into
the steel mill

One of the biggest technical challenges is to integrate the new equipment into the existing steel mill. This project has not yet been implemented anywhere in the world. Salzgitter could therefore be the first steel company to successively incorporate a direct reduction plant into an integrated steel mill.


With the MACOR feasibility study, our team from Salzgitter Flachstahl and Salzgitter Mannesmann Forschung, together with Fraunhofer institutes, examined whether the plans for CO2 reduction in our steel mill - in addition to technical and ecological requirements - also meet economic requirements. The feasibility of SALCOS® depends, among other things, on how the EEG levy will develop, for example. In addition, extensive calculations have already been carried out.

Responsibility for
the region and employees

With SALCOS® , we made a conscious decision to design the scenario in such a way that the equipment could be used in our integrated steelworks at the Salzgitter site. Relocating production to non-European countries in order to reduce the need for CO2 certificates, so-called carbon leakage, contradicts our idea of regional and global responsibility.

EU emissions

For CO2-emissions, companies within the European Union must buy certificates that allow them to emit a certain amount of carbon dioxide. These papers are traded in Europe. In order to reduce emissions in the future, the availability of certificates is to be drastically reduced in the 4th trading period starting in 2021. As a result, the certificate price (European Union Allowance (EUA)) is to be increased. These enormous additional costs will only affect European corporations, which will jeopardize or even lose their international competitiveness as a result.

Responsibility for
our environment

We understand sustainability as a concept of holistic responsibility. For this reason, we have opted for the so-called "Carbon Direct Avoidance (CDA)" strategy, in which the CO2 that has so far been produced process-related during the reduction of iron oxide in the blast furnace is avoided directly. With SALCOS® we are developing a concept for this project.


Our project is technically very mature and can be implemented in a timely manner. The SALCOS® team and various external experts are continuing to work on optimizing the SALCOS concept . SALCOS implementation envisages a transformation process lasting several years in which blast furnaces and converters are gradually replaced by direct reduction plants and electric arc furnaces.

climate targets

The European Union is playing a major role in global climate protection. To this end, it has already formulated numerous programs and regulations aimed at reducing CO2 emissions, particularly in the industrial sector. One important instrument for this goal is emissions trading. Compared to 1990 levels, CO2 emissions in the EU are to be reduced by 55% by 2030, with the aim of achieving climate neutrality by 2050.