Extruded Profile Seal for Hydrogen Applications

Precision-molded Elastomer Seals for the Hydrogen Market

Freudenberg Sealing Technologies (FST) has successfully developed a new extruded profile seal for use in hydrogen production, specifically in alkaline electrolysis processes. This innovation was achieved in a short timeframe through collaboration between multiple departments. The seal was designed for a prominent European manufacturer of alkaline electrolyzers and showcases FST’s practical application of its hydrogen-related development capabilities.

The project faced challenges due to constraints in the electrolysis stack’s existing design, limiting the flexibility for seal customization. However, FST managed to optimize the profile seal's design using extensive analyses, calculations, and testing. The original flat seal design from a competitor was replaced with a spherical geometry that increased functional overlap with contact surfaces while reducing the groove filling problem of the previous design. This improvement enhanced the overall effectiveness of the seal.

Another significant focus was on developing a sustainable and durable material to replace asbestos, which posed health risks. In alkaline electrolyzers, the sealing material must withstand the harsh conditions created by a concentrated potassium hydroxide solution and oxygen, both of which accelerate material deterioration. The material also needed to ensure a long operational lifespan under high pressure and temperature conditions. After a thorough review of FST's material portfolio, an EPDM (ethylene propylene diene monomer) material was selected as the optimal solution. In rigorous storage tests, it outperformed the material of a competing product in resisting potassium hydroxide and oxygen exposure.

Each electrolysis cell requires a profile seal of about five meters in length, and FST’s seals are manufactured using endless extrusion. The estimated production volume is around 500 kilometers of seals per year. As of September 2023, the seals were under evaluation by the customer, and initial orders for serial production had already been placed.

Following the success of the initial project, the customer expressed interest in expanding the partnership with FST for future generations of electrolyzers. This next phase would allow FST to contribute its expertise to broader aspects of sealing system design, enhancing the performance of future electrolyzers.

Hydrogen is projected to play a crucial role in the decarbonized future, with growing demand in the chemical industry, sustainable energy storage, and fuel cell technology. For FST, projects like these are essential, as they align with the company's mission to innovate continuously, set new standards, and solidify its position in emerging technologies.

Learn more on FST’s solutions for the hydrogen market

Contact Name:   Donna Thompson-Gough
Tel No:               +44 7851 121882
Email:                donna.thompson-gough@fst.com

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