The EU Commission has identified the production and use of clean H2 has a key lever for the industry decarbonation, as fuel for transportation and storage vector for renewable electricity on a large scale. RePowerEU plan set out the target of doubling the EU renewable H2 in the coming years. To achieve this ambition, the EU needs to upscale significantly the domestic manufacturing capacities with innovative equipment.
Electrolysers appear as a competitive solution to reach the clean H2 production level set by the EU. However, the use of H2 requires various pressure levels depending on the chosen processes and applications, which systematically involves additional pressurisation steps, after the production, to allow storage, transportation or use.
The compression of H2 is very energy-intensive, especially for the first bars. Hence, producing pressurised H2 directly in the electrolyser can bring major relief on the compression costs, reduce the technological complexity and positively impact the global process efficiency and furthermore a potentially smaller footprint.
In this context, PressHyous, an EU R&D project funded by the Clean H2 partnership, aims to produce low-carbon pressurised H2 at reduced cost, around 3€/kg by 2030. It will prove the concept through the operation of a 20 kWe pressurised lab-scale device (eq. 13.5 kg H2/day). This lab-scale device will be composed of a Solid Oxide Electrolysis (SOEL) stack located in a pressurised vessel, and will be operated up to 30 bar at, at least, 1 A/cm², close to the thermoneutral voltage during 4000 hours. The project also aims to investigate an innovative stack concept, without pressure vessel, thus reducing the cost of Balance of Plant, by testing this solution up to 10 bar on a short stack scale, at similar current density to the stack operated in the pressurised vessel. To reach objectives, both stacks will integrate optimised components, notably electrochemical cells and sealings, improved for pressurised operating. To complement the practical testing of the PressHyous concepts, the project will deliver model-based insights for H2 production under pressure for up to 5 identified use cases, on expectable performances of both stack concepts (with or without pressurised vessel) towards large scale developments up to 100s MWe, coupled with techno-economic and life-cycle analysis.
