Technologies can be developed to increase the proportion of hydrogen fed into the shaft furnace up to 100%. Where renewable energy is used to produce ‘green hydrogen’ for use in this way, it directly displaces CO2. However, where insufficient levels of renewable energy are available, industry will need to use ‘blue’ hydrogen, derived directly from fossil fuels or industrial gases and combined with carbon capture and storage (CCS) to ensure carbon neutrality.

ArcelorMittal is developing a new, innovation project at our Hamburg site in Germany aimed at the first industrial scale production and use of Direct Reduced Iron (DRI) made with 100% hydrogen as the reductant, with an annual production of 100,000 tonnes of steel.

The process of reducing iron ore with hydrogen will first be tested using grey hydrogen generated from gas separation. We aim to achieve the separation of H2 with a purity of more than 97% from the waste gas of the existing plant, using a process known as ‘pressure swing absorption’.  This will allow us to develop technological solutions at industrial scale to reduce iron ore with only Hydrogen and in absence of carbon. Many technical and practical challenges are ahead of us, which only can be solved in an operational plant, something that has never been done up to now due to lack of hydrogen infrastructure.

Hydrogen gas reduction

In the future, the plant should also be able to run on green hydrogen when it is available in sufficient quantities at affordable prices, with the clean energy for hydrogen production potentially coming from wind farms off the coast of Northern Germany.

In September 2019, ArcelorMittal announced the signing of a Framework Collaboration Agreement (FCA) with Midrex Technologies to design the Hamburg demonstration plant and work on several related R&D and innovation projects.

"We are working with a world class provider, Midrex Technologies, to learn how you can produce virgin iron for steelmaking at a large scale by only using hydrogen. This project, combined with our ongoing projects on the use of non-fossil carbon and on carbon capture and use, is key to becoming carbon neutral in Europe in 2050. Large-scale demonstrations are critical to show our ambition. However, how fast transformation will take place will depend on the political conditions." Carl de Maré, Vice President at ArcelorMittal and responsible for technology strategy.

ArcelorMittal Hamburg already produces steel using DRI technology. During the process, iron oxide pellets are reduced to metallic iron, the raw material for high quality steel, by extracting oxygen using natural gas. "Our site is the most energy-efficient production plant at ArcelorMittal", says Dr Uwe Braun, CEO at ArcelorMittal Hamburg, adding that the existing Midrex plant in Hamburg is also the plant with the lowest CO2-emissions for high quality steel production in Europe.

"With the new, hydrogen-based DRI plant we are now planning, we will raise steel production to a completely new level, as part of our Europe-wide ambition to be carbon neutral by 2050" Dr Braun concludes.