Periodic Reporting for period 1 - HYPRAEL (Advanced alkaline electrolysis technology for pressurised H2 production with potential for near-zero energy loss)
Reporting period: 2023-03-01 to 2024-08-31
HYPRAEL addresses climate change and the need for energy transition by developing advanced electrolysis technology for highly compressed hydrogen production. The project’s goal is to transform alkaline electrolysis (AEL) technology to achieve hydrogen output pressures of 80 bar, improving energy efficiency and reducing costs compared to conventional electrolysis. As a signatory to the Paris Agreement and committed to decarbonization, the EU requires hydrogen innovations that integrate into industrial and transportation infrastructures to meet climate neutrality goals. The European Hydrogen Strategy and REPowerEU initiative set ambitious 2024 and 2030 targets, accelerating hydrogen infrastructure across Europe.
The project addresses efficiency and cost challenges in hydrogen compression, especially for high-pressure transport or storage. Traditional AEL electrolyzers need extra compression to reach these pressures, requiring costly equipment and high energy consumption. HYPRAEL mitigates this by developing an electrolyzer that directly produces hydrogen at 80 bar or more, reducing or eliminating additional compression needs. This leads to lower costs and higher efficiency, crucial for applications like gas grid injection, green methanol synthesis, and offshore wind turbine integration.
HYPRAEL develops components that enable high-pressure and high-temperature operations, overcoming AEL’s limitations. Key advancements include:
- Separator and Membrane Designs
- Electrodes and Catalysts
- Increased Operating Temperature
- High-Pressure Stack Designs
- Industrial-Scale Validation (50-kW prototype electrolyzer at 80 bar and 120°C)
HYPRAEL aims to reduce the levelized cost of hydrogen (LCOH), enhancing efficiency by around 2-4% (LHV). This technology will contribute to Europe’s decarbonization goals, facilitate renewable integration, optimize electricity use, and support hydrogen storage and transport for industry. The project aligns with the EU’s commitment to global hydrogen leadership, addressing eight UN Sustainable Development Goals, including climate action, clean energy, and industrial innovation.
The project addresses efficiency and cost challenges in hydrogen compression, especially for high-pressure transport or storage. Traditional AEL electrolyzers need extra compression to reach these pressures, requiring costly equipment and high energy consumption. HYPRAEL mitigates this by developing an electrolyzer that directly produces hydrogen at 80 bar or more, reducing or eliminating additional compression needs. This leads to lower costs and higher efficiency, crucial for applications like gas grid injection, green methanol synthesis, and offshore wind turbine integration.
HYPRAEL develops components that enable high-pressure and high-temperature operations, overcoming AEL’s limitations. Key advancements include:
- Separator and Membrane Designs
- Electrodes and Catalysts
- Increased Operating Temperature
- High-Pressure Stack Designs
- Industrial-Scale Validation (50-kW prototype electrolyzer at 80 bar and 120°C)
HYPRAEL aims to reduce the levelized cost of hydrogen (LCOH), enhancing efficiency by around 2-4% (LHV). This technology will contribute to Europe’s decarbonization goals, facilitate renewable integration, optimize electricity use, and support hydrogen storage and transport for industry. The project aligns with the EU’s commitment to global hydrogen leadership, addressing eight UN Sustainable Development Goals, including climate action, clean energy, and industrial innovation.
Veco, Fraunhofer IFAM, and Fraunhofer IWS Dresden collaboratively developed and tested long-term stable substrates and Raney Ni-based catalysts for hydrogen and oxygen evolution in high-temperature, pressurized electrolysis. Specifically, they have focused on achieving stability in 120°C, 40 wt.% KOH. Fraunhofer IFAM designed a new test infrastructure to accommodate these extreme conditions, as durability data for materials and sensors under such conditions is limited.
Significant findings emerged from the uniform testing of Ni-based catalyst layers on Ni substrates by Veco. These tests provided insights into the behaviour of the layers concerning temperature, coating thickness, and substrate form factors.
Fraunhofer IFAM’s 3EA test infrastructure in Dresden was also adapted to measure at temperatures above 100°C, preventing electrolyte contamination from Si or Fe. A slight degradation was observed, which can be attributed to the highly concentrated KOH solution (40 wt%). Even at 80°C, the higher concentration has a negative impact. It is worth to mention that the catalyst system can be used as a bifunctional system (HER and OER). Additionally, AGFA separators were successfully coated using atmospheric plasma spraying (APS), to improve durability under high-temperature, high-pressure electrolysis.
The current separators used in state-of-the-art alkaline electrolyzers are not designed for increased temperature and pressure. The optimization strategies focused on pore structure, hydrophilicity enhancement and the thermal stability. Through collaborative work between AGFA and Syensqo, polymers of different families with enhanced stability have being screened for the required temperature and KOH concentration with conclusive results still pending. In paralell, Zirfon membrane is also being optimized, with a method developed to reduce gas crossover caused by higher pressure.
FHA’s pilot-scale test bench is nearly upgraded, with component and control logic selected to meet high-pressure, high-temperature demands.
Significant findings emerged from the uniform testing of Ni-based catalyst layers on Ni substrates by Veco. These tests provided insights into the behaviour of the layers concerning temperature, coating thickness, and substrate form factors.
Fraunhofer IFAM’s 3EA test infrastructure in Dresden was also adapted to measure at temperatures above 100°C, preventing electrolyte contamination from Si or Fe. A slight degradation was observed, which can be attributed to the highly concentrated KOH solution (40 wt%). Even at 80°C, the higher concentration has a negative impact. It is worth to mention that the catalyst system can be used as a bifunctional system (HER and OER). Additionally, AGFA separators were successfully coated using atmospheric plasma spraying (APS), to improve durability under high-temperature, high-pressure electrolysis.
The current separators used in state-of-the-art alkaline electrolyzers are not designed for increased temperature and pressure. The optimization strategies focused on pore structure, hydrophilicity enhancement and the thermal stability. Through collaborative work between AGFA and Syensqo, polymers of different families with enhanced stability have being screened for the required temperature and KOH concentration with conclusive results still pending. In paralell, Zirfon membrane is also being optimized, with a method developed to reduce gas crossover caused by higher pressure.
FHA’s pilot-scale test bench is nearly upgraded, with component and control logic selected to meet high-pressure, high-temperature demands.
There is currently limited global activity in high-temperature AEL. Most groups use molten salt, but this is considered too distant for commercial implementation. The consortium is advancing existing AEL technology to use 30 wt.% KOH with increased pressure. Initial tests focused on material properties at elevated temperatures. Fraunhofer has set up a system to test materials up to 120°C, allowing for accelerated material fatigue tests for classic AEL and for establishing infrastructure for long-term cell tests under challenging conditions. Meanwhile, materials were developed to withstand high demands of 120°C, especially in corrosion stability. In collaboration with Veco, Fraunhofer produced dimensionally stable electrodes and tested the SEA concept (direct separator coating via APS), both showing promising lab-scale results.
With promising initial results from the latest polymer in terms of enhanced thermal and alkaline stability, the next stage of trials is ongoing. At the same time, a method to optimize the Zirfon membrane is being developed to reduce gas permeability by 30–80%, with a maximum resistivity increase of 10%. The next phase will integrate these advancements into a next-generation membrane
Fundamental research is essential to establish key parameters for high-pressure electrolysis. At high pressures, oxygen enters a supercritical state, requiring evaluation of its interaction with the gas-separating diaphragm. Tests are envisioned to confirm electrode performance at 80 bar and 110°C.
With promising initial results from the latest polymer in terms of enhanced thermal and alkaline stability, the next stage of trials is ongoing. At the same time, a method to optimize the Zirfon membrane is being developed to reduce gas permeability by 30–80%, with a maximum resistivity increase of 10%. The next phase will integrate these advancements into a next-generation membrane
Fundamental research is essential to establish key parameters for high-pressure electrolysis. At high pressures, oxygen enters a supercritical state, requiring evaluation of its interaction with the gas-separating diaphragm. Tests are envisioned to confirm electrode performance at 80 bar and 110°C.