GrInHy – SZFG is running the world's most powerful reversible high-temperature electrolysis

GrInHy – SZFG is running the world's most powerful reversible high-temperature electrolysis
Within the context of the GrinHy project Salzgitter Flachstahl GmbH is operating the world's most powerful reversible high-temperature electrolysis. GrInHy stands for "Green Industrial Hydrogen via reversible high-temperature electrolysis”. Coordinated by the affiliate Salzgitter Mannesmann Forschung GmbH and with six additional partners, the EU-funded project has been running since March 2016.

The project's central element is the construction and first operation of a reversible high-temperature electrolyzer in a relevant industrial setting. High-temperature electrolysis technology is based on a solid oxide electrolyte, which enables the reversible operation of the test facility. In electrolysis operation, steam, preferably from waste heat sources, is converted into hydrogen and oxygen. By integrating thermal energy in the form of steam, this electrolysis technology achieves the highest electrical efficiency. In the reverse case, which is fuel cell operation, the system generates electricity and heat from hydrogen or natural gas, likewise with good efficiency.

The GrInHy test facility comprises two units: the reversible high-temperature electrolyzer and the subsequent hydrogen treatment system. In electrolysis mode, the system, with a nominal connected rating of 150 kW alternating current, produces some 40 standard cubic meters of hydrogen an hour, whereas in fuel cell operation, it has a nominal electrical generation capacity of 30 kW alternating current. In order also to use the hydrogen in the steel refinement annealing processes, the produced hydrogen must comply with quality level 3.8 (> 99.98% hydrogen). This is achieved by first compressing the saturated hydrogen at a gauge pressure of 8 bar and then drying it in a pressure swing absorption system.

Both units were installed at the SZFG integrated steel works in June 2017. Since then, the test facility has spent more than 5,000 hours either in operation or ready for operation in so-called "hot-standby" mode. The generation of more than 45,000 standard cubic meters of hydrogen alternating current has already proven the reversible operation's technical functionality. The system was also already able to feed 15,000 standard cubic meters of hydrogen to the plant's own hydrogen line in the first continuous operation.

Against the background of the SALCOS^® (Salzgitter Low CO₂-Steelmaking) concept, the GrInHy project is a preliminary technical study to test energy-efficient hydrogen production.

You will find further details and current information on the website:
https://salcos.salzgitter-ag.com