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Green Industrial Hydrogen via Reversible High-Temperature Electrolysis

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Green industrial hydrogen production powering Europe along the road to a decarbonised future

Renewable electricity sources are not always constant, which presents a problem in the move towards low-carbon economies. The award-winning GrInHy project developed a prototype technology that creates green, flexible hydrogen energy at high efficiency to enable ultra-low emission steel.


A major challenge for society today is the shift towards competitive, low-carbon economies. To achieve this goal – with the target of 2050 set by the European Commission - all sectors of the economy will need to use renewable electricity extensively. Yet renewable energy sources are often intermittent, and not every sector can be electrified. High-temperature electrolysis (HTE) is one of the most promising technologies to get around these problems, providing a highly flexible, efficient energy source. “The key aim of GrInHy was to manufacture the world’s largest reversible High Temperature Electrolyser (HTE) able to produce hydrogen when renewable electricity is available, and generate electricity from hydrogen or natural gas when renewable electricity is scarce,” says Mr Simon Kroop, from Salzgitter Mannesmann Forschung and GrInHy project coordinator. “All project objectives and milestones were reached with only minor deviations,” says Kroop. A flexible and dynamically applicable prototype – using technology developed by Sunfire GmbH – was successfully designed, manufactured and embedded into an existing iron-and-steel works. The GrInHy team demonstrated the potential production of green hydrogen via HTE for the Salzgitter AG's hydrogen-based, low-carbon steelmaking concept to reduce total emissions by more than 95 % - going way beyond today's use for the annealing processes. Due to the project’s success, GrInHy was nominated for the 'FCH JU Awards 2018 Best Project Innovation'. Reuse, recycle, repeat Steam is split into hydrogen and oxygen in a very efficient manner by means of high temperature electrolysis. Because the energy input (steam) is essentially waste heat, the system functions much more efficiently, and sustainably, than conventional technologies. “The largest electrical efficiency benefit is the direct use of industrial steam from waste heat at around 150 °C from processes taking place in the iron-and-steel works. This not only results in a lower electrical energy demand compared to other electrolyser technologies but also in lower operational energy costs,” says Kroop. In approximately 10 000 hours of total operation, the prototype was run either in electrolysis, fuel cell or hot-standby mode. “Most important is the fact that the electrolyser directly used industrial steam from waste heat processes to produce hydrogen that met the quality requirements for the steel annealing processes of the iron-and-steel works,” Kroop explains. Good work all round “I’m most proud about the exceptional teamwork of the European project consortium. We had eight partners from five different EU countries. In total more than 30 experts and researchers of different professions worked closely together to take a major step for the HTE technology towards a marketable product,” says Kroop. The GrInHy team assessed the technology’s cost structure, potential business case and environmental performance in accompanying studies. The project also gained high levels of public awareness through scientific conferences, international fairs and dedicated hydrogen technology workshops. Although the official project ended in February 2019, the prototype will still operate until mid-2020, when the GrInHy prototype will be replaced by its successor. The GrInHy2.0 project, which started in January this year, will exploit all results and experiences to increase the electrolyser nominal capacity: a five times higher production rate than the previous GrInHy prototype. “We have proven that HTE works in the industrial environment and are now scaling up. To exploit the full potential of green hydrogen in different industries, we need a favourable legal framework for an economical usage of ‘green’ hydrogen,” says Kroop.


GrInHy, energy, hydrogen, renewable, low-carbon, efficient, iron-and-steel, flexible

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