SALCOS Project: A Steel Giant Wants to Become Greener

For some time now, Salzgitter AG has been working on producing steel as resource-efficiently as possible. That's why the company from Lower Saxony, Germany, operates its integrated steelworks in Salzgitter on a virtually energy autonomous basis and closes material loops to enable residual material and cogenerated products to be reused within the company or across sectors. As a result, the company is already one of the world's most efficient steel producers.

Despite this, the steelworks generates around eight million tons of CO2 annually, which are unavoidable for process-related reasons under the given technical conditions and with the available facilities. In order to improve the ecological footprint nonetheless, researchers and experts in the Group's production, in cooperation with Fraunhofer Institutes and other partners, are looking into new technologies and the possibility of integrating them in the SALCOS® (SALCOS - Salzgitter Low CO2 Steelmaking) project.

The company explains the idea behind the project as follows: "In Europe, iron ore is currently almost exclusively reduced in blast furnaces using carbon, mainly in the form of coke, coal and hydrocarbons (oil, natural gas). This inevitably results in CO2 emissions. However, in special systems, so-called direct reduction plants (DRP), carbon can be largely replaced by hydrogen as a reducing agent in iron ore reduction. In such a reactor, iron ore could therefore first be reduced to iron with the aid of natural gas and an increased addition of hydrogen. The reaction takes place at 950 degrees and sponge iron is formed. Furthermore, this plant is an integrated process. The gas is circulated and, after separation of the water resulting from the reduction, the remaining CO2 is removed and used further. The challenge of direct reduction is the integration of the new plants into the existing steelworks. With a step-by-step implementation of such a reactor, a CO2 saving of up to 50% is theoretically possible in the first instance. Should it be possible in the future to carry out the entire production process with direct reduction plants, this value could rise to up to 85%".

Aerial photo of the "Windpark Salzgitter" construction site (Image: Salzgitter AG)

However, this project has not yet been technically and economically feasible, which is why the researchers are working together on a concept for a gradual conversion. A further step has now been initiated: Construction of the Group's own Windpark Salzgitter with seven wind turbines has begun. Three of the turbines will be erected on the site of the integrated steelworks of Salzgitter Flachstahl GmbH - which belongs to Salzgitter AG - and another four on the surrounding Group premises.

The 30 MW wind farm with Vestas turbines is a further component of the 'Windwasserstoff Salzgitter' project, which is intended to generate green hydrogen for steel production. For this reason, a PEM electrolysis plant will be set up on the Salzgitter Flachstahl site this year, with Siemens supplying the equipment. The hydrogen will then be used in the production chain at Salzgitter Flachstahl GmbH, and will play a key role in the future design of SALCOS.