Sealing Solutions for H2 Production

Electrolyzers splitting water into oxygen and hydrogen using electricity are one option for producing green hydrogen from renewable energy sources. Efficient hydrogen production requires large electrolysis systems that, in addition to temperature, media, pressure, and long-term resistance, make special demands on the sealing systems due to their sheer size.

Electrolysis is a process that has been known and used in industrial settings for a long time. Electrolysis splits water into oxygen and hydrogen using electrolyzers.

Examples of commonly used electrolysis systems are alkaline electrolyzers, PEM electrolyzers, and solid oxide electrolyzers, each of which make different demands on the sealing solutions. Alkaline electrolyzers, for instance, make high demands on chemical resistance and service life. PEM electrolyzers are less demanding in terms of chemical resistance but these systems require reliable and low-permeation sealing solutions to meet exacting service life and safety requirements. Solid oxide electrolyzers that, due to high operating temperatures, clearly limit or rule out the use of polymer seals such as rubber seals call for other sealing solutions such as metallic sealing systems.

Aside from the requirements resulting from the diverse operating conditions of electrolysis systems, seals, especially those for bipolar plates or similar seals close to the stack, must have a simple, functionally reliable and easy to install design to enable cost-efficient mass production of electrolysis systems.

Steam reformation is currently the most commonly used technology for producing hydrogen. Parker Prädifa offers an extensive range of sealing solutions for a wide variety of applications in the area of steam reformation.

Steam reformation is a large-scale industrial process primarily used to produce “gray” hydrogen usually from natural gas or other hydrocarbon compounds. Sealing solutions from Parker Prädifa can be found in many places of steam reformation systems, both in the reformer itself and in adjacent assemblies such as line connectors, valves, pumps, or storage systems. High-performance seals made of a specialty FFKM compound are used here for sealing off hydrogen at up to 240 °C. In other places with lower temperature requirements, more economical EPDM or FKM O-rings are installed. Using seals made of butyl materials can minimize hydrogen leakage due to particularly high permeation resistance, which may be of crucial importance in storage systems for instance.

Hydrogen can also be produced using various biochemical methods. These are mainly novel technologies that, in addition to chemical resistance, require maximum purity.

Biochemical technologies, among other things, use algae or bacteria to produce “bio hydrogen.”  Green algae, for instance, can split water into oxygen and hydrogen by means of a special enzyme (hydrogenase).

The production of hydrogen using living organisms takes place in so-called bioreactors that make special demands on the sealing system. On the one hand, these are exacting requirements for the purity of the seals to prevent endangering the living bioorganisms inside the reactor due to contaminations. On the other hand, the sealing system, in addition to chemical resistance against the nutrient solutions in which the algae produce the hydrogen, must enable easy and reliable cleaning of the total system. This serves to largely exclude a potential contamination risk due to residual dirt, for instance in undercuts of the sealing systems, where dirt deposits may permanently accumulate.

Based on decades of experience in the food and pharma industries, Parker Prädifa offers sealing solutions featuring hygienic and undercut-free designs as well as compounds specifically developed for food and pharmaceutical applications characterized by high purity. These reliable sealing solutions comply with relevant standards and approvals and ensure maximum purity for non-contaminating media, as required.