Freudenberg Sealing Technologies is on track for growth with the leading manufacturer of AEM electrolyzers.
Picture a single-family home that generates green electricity in the summer with a photovoltaic system on the roof. Come winter, this same house is heated with precisely this green energy generated during the summer. And this without needing a massive battery to store the electricity.
This “only” takes three components: first, an electrolyzer that converts green electricity into green hydrogen during the summer; second, a storage tank for the hydrogen that is produced; third, a fuel cell to convert the stored hydrogen back into electricity and heat in the winter. A gas heating system that is “H2-ready” and already commercially available could also serve for this last step.
Producing Hydrogen from Water using Electrolysis
This scenario is just one among countless potential applications for the so-called AEM electrolyzers developed by Enapter AG. It should be noted that there are a number of methods for producing hydrogen from water through electrolysis. Each has different advantages and is suitable for various uses. Enapter is a German-Italian technology company that specializes in electrolyzer modules for generating green hydrogen via the AEM (anion exchange membrane) process. Enapter is currently the absolute market leader for this electrolysis technology. Freudenberg Sealing Technologies (FST) has come on board as a development partner as the venture quickly expands.
Current research and development indicates that the AEM process is particularly fitting for residential and medium-sized commercial applications. Enapter AEM electrolyzers are used in industries such as glass manufacturing and brick factories, for instance. Other electrolysis processes are more suitable for large-scale demands, such as those of steel mills.
Six Sealing Points per Cell
The audience can hardly keep up and is clearly amazed when Christoph Reissenweber, Key Account and Project Manager Hydrogen Technologies at Sales General Industry, mentions unit numbers, growth rates, objectives, and the ongoing and future projects that FST is already pursuing and envisioning with Enapter. “Enapter is on the verge of transitioning from small to large-scale production. We are proactively accompanying and supporting the company, devising reliable solutions for the current and future generations of electrolyzers,” he explained.
An AEM electrolysis system basically includes one or several combined stacks, which together constitute a complete system via the so-called balance-of-plant. Enapter’s AEM stack modules offer a plug-and-play solution capable of producing up to 450 kilograms of hydrogen per day. These Enapter stacks are composed of 25 individual cells, each of which has six points that must be sealed to the others using five distinct seal designs. This means that a single stack contains over one hundred sealing points. A complete electrolyzer, in turn, often consists of several hundred such stacks – which explains the enormously high quantities involved in the sealing business with Enapter.
At the end of 2023, FST secured the series order for three products along with orders for the first half of 2024. An abbreviated validation process is currently underway for the fourth sealing point. The first three series orders are for O-ring seals. The complexity of the fourth sealing point requires an asymmetrical seal design – a gasket – which FST has developed specifically for high-pressure electrolysis applications. Series production of this gasket is already expected to start this summer. This premium solution maintains both the electrolyte used in the electrolyzer (a potassium hydroxide solution) and the hydrogen within the desired ranges. The customer, in turn, is even adjusting the design of the thermoplastic cell frame.
Rapid Prototyping
But that isn’t all. For the next generation of electrolyzers – no longer round, but rectangular and more powerful – FST is developing a two-component solution for Enapter, which will incorporate all seals directly into the plastic cell frame: a huge added value for the customer. “We are going so far as working in advance for this project. At the moment, we are honing our skills and capabilities so that we can provide Enapter with the thermoplastic cell frame with integrated seals in the future. The first prototypes of these cell frames are already completed. Small batches of all necessary gaskets for this integrated solution are being produced through our in-house rapid prototyping service. This makes it possible for us to develop with precision and perform competent tests,” Reissenweber said.
By the way, FST also has application- and customer-specific solutions up its sleeve for other electrolysis processes, with numerous projects currently in motion.
Christoph Reissenweber, Artur Mähne, Hendrik Scherff, Michel Paschert and Herbert Mayer.
