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Green Industrial Hydrogen via steam electrolysis

Periodic Reporting for period 1 - GrInHy2.0 (Green Industrial Hydrogen via steam electrolysis)

Reporting period: 2019-01-01 to 2020-06-30

Clean Hydrogen from renewable energies is key to a successful cross-sectoral energy transition enabling the EU’s low-carbon economy goal in 2050. However, access to renewable electricity will be a limiting factor in the future and energy efficient technologies will still be important. Due to a significant energy input in form of steam preferably from industrial waste heat, High-Temperature Electrolysis based on Solid Oxide Electrolysis Cells (SOEC) achieves outstanding electrical efficiencies.

Essential element of the GrInHy2.0 project is to produce hydrogen the most energy efficient way while increasing the technological maturity of the High-Temperature Electrolyser (HTE). Although starting with hydrogen production for today’s steel annealing processes, GrInHy2.0 marks an important milestone towards a hydrogen-based, low carbon European steel industry. Here, hydrogen has the potential to reduce today’s process related CO2 emissions by more than 95 %.

The Salzgitter companies Salzgitter Flachstahl GmbH and Salzgitter Mannesmann Forschung GmbH together with the partners Sunfire GmbH, Paul Wurth S.A. Tenova SpA and the French research centre CEA will work together at the world’s most powerful HTE for the energy efficient production of hydrogen. Further, the consortium will contribute to a detailed analysis of the potentials of renewable hydrogen in the iron-and-steel industry as well as the in-depth understanding of SOEC long-term behaviour on stack level.

With the first implementation of a high-temperature electrolyser of the Megawatt-class, GrInHy2.0’s prototype will produce 200 Nm³/h of hydrogen at nominal power input of 720 kWAC. The HTE system consists of up to eight modules with 720 or 1,080 SOECs each, i.e. 24 or 36 stacks, respectively.

As in the predecessor project GrInHy, the prototype will be fully integrated into Salzgitter’s steelmaking operations and will run on steam from waste heat of the steel production. By the end of 2022 it is expected to have been in operation for at least 13,000 hours, producing a total of around 100 tons of high-purity ‘green’ hydrogen at electrical efficiency of minimum 84 %LHV.

In parallel to the prototype testing operation, a singular stack of the SOEC technology will set new standards in long-term testing with a test bench operation of at least 20,000 hours. The test will not only show the technology’s increased robustness but also provide potential starting points for further improvement.

In a broader perspective, the project will also deliver answers on how to avoid CO2 emissions in the European steel industry by switching to a hydrogen-based primary steelmaking and what it takes.
Since its start in January 2019, the project progressed with minor changes according to the work plan. The GrInHy2.0 project is divided into six Work Packages.

The first 18 months were mostly dedicated to the design and manufacturing of Sunfire’s 720 kWAC High-Temperature Electrolyser with a nominal hydrogen production rate of 200 Nm³/h and Paul Wurth’s Hydrogen Processing Unit that compresses and dries the hydrogen before injection into the pipeline. In parallel, the preparation of the installation site started in Salzgitter, where the on-site assembling of the system will take place in August 2020.

As planned in Description of Action, CEA started in the second quarter of 2019 with procurement and installation of the test bench for the long-term stack testing of at least 20,000 hours. Due to technical challenges and partially the corona crisis, however, the start of the continuous stack test had to be re-scheduled to June 2020 and, therefore, will be extended for another quarter in 2022.

In parallel to the streams ‘prototype operation’ and ‘stack testing’, the regulatory framework concerning the production of ‘green’ hydrogen according to the CertifHy scheme has been analysed. It has been pointed out that for high-temperature steam electrolysers that use waste heat as a secondary energy input, CertifHy does not provide a clear pathway. Based on Sunfire’s and SZMF’s analysis, we recommend categorizing waste heat as renewable, carbon-neutral input energy source, if:
• the source of waste heat is unavoidable, and
• no additional direct or indirect CO2 emissions occur.

Nevertheless, together with SZFG a clear action plan to reach at least 100 tons of ‘green’ hydrogen according to the CertifHy scheme has been agreed up on by simply producing more hydrogen. That is, however, no mid-term solution and the topic of unavoidable, industrial waste heat must be addressed appropriately soon.

The techno-economic study started as planned with the definition of scope and goal involving all relevant partners. The study will include the results of Tenova’s pre-study about the potential of hydrogen usage in integrated steel works as replacement of carbon carriers in reduction processes directly reducing CO2 emissions. Central element of Tenova’s study was the transformation of today’s blast furnace steelmaking into a direct reduction route based on the hydrogen powered ENERGIRON-ZR process. This concept would result in a 95 % CO2 reduction of an entire iron-and-steel works.
Presently, HTE technology, besides its advantages presents a degree of maturity inferior to water electrolysis technologies. A specific challenge of the project is to bring HTE closer to the maturity level of PEM and alkaline electrolysers. This project is a large step in this direction. GrInHy2.0 focuses on designing and manufacturing the most powerful SOEC system and on operating it at an integrated iron-and-steel works. Therefore, the project addresses the progress against state-of-the-art from several angles:
This includes the technology itself at stack and system level, on one hand, as well as the integration of green hydrogen from a decentralised electrolyser into the processes of the European steel industry, on the other.

Through a multitude of improvements (e.g. efficiency, durability, costs), GrInHy2.0 will significantly impact the competitiveness of green hydrogen production compared to fossil alternatives such as steam methane reforming, as well as the competitiveness of green hydrogen used in Direct Reduction compared to traditional coal-based reduction processes. Furthermore, GrInHy2.0 will change the perception of the use of green hydrogen in industrial processes by demonstrating a viable large-scale application for the use of renewable energy. The generated information on the operational, technical and financial performance of the HTE itself and the illustration of the integration into the commercial and technical processes of the customer will ensure that the results have the maximum impact for further market deployment. The aim is to create a viable market by demonstrating how HTE can work in a complex industrial environment improving carbon reductions over existing technologies. Therefore, the project results will be disseminated to decision makers that are likely to commission similar facilities in the near future (potential customers in the same or other relevant industries) and those who provide supportive policies for the technology (e.g. national governments and people of public interest). GrInHy2.0 will provide a significant share of green hydrogen to the iron-and-steel works and will in addition provide an assessment on the EU market based on the CO2 avoidance potential of hydrogen for the European industry as a whole.