FlexElec - AEM test set up at H2 Lab

In Gelderland at industriepark Kleefsewaard, a prominent knowledge hub for hydrogen technology has been developed, featuring key industry players and research groups contributing to innovative and cost-effective hydrogen technologies. However, the region faces a challenge in the lack of available test equipment for hydrogen innovations. In Anion Exchange Membrane (AEM) technology, a route to follow is to create hydrogen more efficiently with stacks that can operate under high pressure (50 bar – 200 bar). This results in compact hydrogen storage. Research must be done to understand crossover effects which become more apparent at these high pressure conditions.
The overall goal is to design a Balanced of Plant (BOP) system, incorporating Process Flow Diagram (PFD) and Piping & Instrumentation Diagram (P&ID) elements, alongside hydrogen purification systems and gas-liquid separators, for a test setup operating AEM stacks at 200 bar.
De Nooij Stainless contributes by designing and fabricating a gas liquid separator, addressing challenges such as compatibility, elevated temperatures, and hydrogen safety. ON2Quest collaborates in supporting the design of a hydrogen purification system and the Balance of Plant (BoP), ensuring flexibility for testing future stacks and hydrogen purification components. HyET E-Trol specializes in high pressure (up to 200 bar) AEM electrolyser stacks and is responsible for providing problem statements and engineering challenges related to the (Balanced of Plant) BoP of AEM systems, and contributes in solving them. Subsequent projects will feature test sequences centered on other stacks, allowing for testing stacks from other companies.
The resulting framework will provide a foundation for ongoing advancements, with contributions from each partner playing a crucial role in achieving the project's goals.

Eindrapportage

Operating AEM electrolysers at elevated pressures (50–200 bar) enables direct high-pressure hydrogen production, reducing downstream compression needs and enabling compact storage. However, such operation introduces challenges related to gas crossover, water management, drying, safety, and balance-of-plant (BoP) integration - particularly due to the limited availability of high-pressure AEM test infrastructure.

This one-year project addresses these challenges by developing a flexible high-pressure BoP design for testing AEM electrolyser stacks up to 200 bar at the HAN H2Lab at Cleantech Park Arnhem. An extensive literature study was conducted, focusing on high-pressure AEM operation, membrane behavior, gas and water crossover, phase separation, drying technologies, and safety considerations. Where experimental data were lacking, extrapolations from low-pressure studies were applied to assess performance and crossover behavior at higher pressures. All this research is documented in a report for future projects.

Based on the research outcomes, a comprehensive requirement list was defined, forming the foundation for system design. Mass and energy balance calculations were performed to dimension flows, thermal loads, and separation stages. A Piping and Instrumentation Diagram (P&ID) was realized, integrating flushing systems, gas-liquid separation, drying stages, hydrogen purification, and safety instrumentation. A conceptual CAD model was developed to visualize the system layout and verify spatial, operational, and safety constraints.
Special focus was placed on water and KOH removal, leading to the sizing and conceptual design of a gas-liquid separation consisting of a knock-out vessel and a coalescing filter, suitable for high-pressure hydrogen streams. This project establishes a technical foundation for high-pressure AEM electrolysis testing and continued innovation in green hydrogen production.