Technology: Freudenberg advances electrolyser seals for hydrogen production

Weinheim, Germany – Freudenberg Sealing Technologies has developed elastomeric sealing solutions for electrolysers that are used for the production of green hydrogen.

In a statement 29 June, FST said it applied its expertise in fuel cell sealing solutions in developing the system for electrolysers, which are being increasingly used to produce hydrogen power from spliting water. 

The company is using a portfolio of proprietary rubber-based gasket materials, including EPDM and FKM formulas, to address the performance requirements and electro-chemistries found in different types of electrolysers.

To produce the system, FST said it overmoulded elastomeric gaskets on to composite and metal electrolyser stack plates in a four-step process.

Stack plates are used to separate the cells in a stack assembly and a crucial component of the plates are gaskets which prevent the leakage of gas into other parts of the electrolyser.

In addition, Freudenberg said it developed material-specific bonding agents that are applied between the gasket and plate materials to ensure the sealing function is optimised.

“As manufacturing industries make strides in moving toward mass green hydrogen production, our ambitious goal is to support demand for high-capacity electrolyser gaskets by 2023,” said Robert Lidster, technical director, gaskets division, Freudenberg Sealing Technologies.

Here, Lidster said FST has tapped into its years of experience in “successfully sealing fuel cell systems.”

“While these do not operate at the pressure and temperature extremes found in high-density electrolysers, they have provided us with a complete understanding of what is required to seal these aggressive environments over a very long lifecycle,” he said.

Freudenberg’s engineers are currently working on gasket integrated electrolyser plates for polymer electrolyte membrane (PEM) and alkaline (AEL) electrolysers.

Due to the differences in the electrolyte materials used in these systems – PEM systems use a solid electrolyte membrane of perfluorosulfonic acid (PFSA) polymers and AEL systems use a liquid electrolyte solution such as potassium hydroxide or sodium hydroxide and water – FST said its facilities collaborate closely with customers to tailor gasket materials and adhesives for optimal performance in different types of electrolyser systems.

According to FST, in addition to pressure and temperature concerns, the company’s engineers also address issues such as corrosion resistance, stability, material breakdown and permeability in different electrolyser environments.

“Freudenberg is continuing its pursuit of innovative sealing solutions for more green power and transportation applications and is pursuing other rubber-coated metal components for electrolysers and other alternate power systems,” the company statement added.

Presently, most hydrogen produced globally uses fossil fuels.

Electrolysis provides a green alternative, using electricity to split water molecules into oxygen and hydrogen gas ions through an electrolyser system.

The hydrogen ions can be used as hydrogen fuel, or recombined with oxygen to create oxyhydrogen gas, which is used in industrial welding and other applications.

“With ambitious, industrial emissions goals quickly emerging, green hydrogen produced via electrolysis will triple in the years ahead, with the major transition starting in 2030,” according to Artur Maehne, global segment manager of hydrogen technologies for Freudenberg Sealing Technologies.

“Many companies are now working on the manufacture of electrolysers, the core of green hydrogen production. Along with established firms, we are seeing many new companies making their way into the market.”

Today, green hydrogen accounts for about 1 gigawatt of power worldwide. Driven by the climate urgency and countries’ commitments to net zero, the International Renewable Energy Agency (IRENA) estimates hydrogen to cover up to 12% of global energy use by 2050.