Since 2019, the project partners have been operating a high-temperature electrolyzer from Sunfire with an electrical connected load of 720 kW on the premises of Salzgitter Flachstahl. The plant is considered the world’s largest and most efficient of its kind.
“GrInHy2.0 is an important part of our SALCOS project for CO2-reduced steel production,” said Dr. Alexander Redenius from Salzgitter Mannesmann Forschung. “Green hydrogen is essential for producing low-CO2 steel, as it reduces carbon emissions very efficiently. With GrInHy2.0, we have gained valuable insights into the integration of electrolysis into our production processes.”
The green hydrogen produced is fed directly into the hydrogen grid of Salzgitter Flachstahl. To date, almost 100 tons of the gas have been used in annealing processes and galvanizing plants for steel finishing. The partnership between Sunfire and Salzgitter AG is to continue beyond GrInHy2.0. “For the transformation of steel production towards hydrogen-based processes, the criteria of availability and cost-effectiveness are becoming increasingly important. Therefore, high-temperature electrolysis is a very interesting technology in the field of steel production, which we will continue to support intensively,” said Dr. Redenius.
Already at the beginning of the year, the Sunfire electrolyzer set new efficiency standards. For the first time, the project partners were able to demonstrate an electrical efficiency of 84% el, LHV, which corresponds to an energy requirement of only 39.7 kWh/kgH2. In addition, the system produced up to 200 Nm3 of green hydrogen per hour.
The electrolyzer is based on the innovative SOEC technology (solid oxide electrolysis cell) and runs at operating temperatures of 850°C. The system utilizes industrial waste heat and renewable electricity to split steam into its components hydrogen and oxygen.
“GrInHy2.0 is an important lighthouse project for Sunfire, in which we successfully demonstrated our SOEC technology on an industrial scale,” said Christian von Olshausen, CTO of Sunfire. “At the same time, we have gained valuable insights for the further technical development. Projects like this lay the foundation for rapidly scaling electrolysis technologies worldwide.”
