PEEK's Place in a Hydrogen Economy
Hydrogen is expected to become a major source of clean energy as we continue to develop renewable energy sources. Gaseous hydrogen can be found in abundance and converting it to liquid hydrogen would help develop hydrogen fuel cells. However, working with hydrogen is not without issues. Whilst we have talked about some component parts in liquid hydrogen storage benefitting from fluoropolymer materials in this blog, there are many other challenges to solve as we evolve away from liquid fuels to gaseous fuels.
AFT currently produces many components that are used within the chemical processing, petrochemical and compressed gas industries- gases including hydrogen. This places us well and gives us a bit of a head start in understanding the equipment and working with compressed gases. We are experts in a whole host of sealing applications, environments and problems- from static to dynamic, liquid to gaseous, corrosive to inert, cryogenic to superheated... The list goes on. We have seen (and sealed) almost every combination of media and circumstance. We have a proven track record and database of knowledge to support us.
PEEK Application in Hydrogen
Applications involving critical sealing and isolation, compression, storage & distribution are not new to AFT. Our knowledge base is a great starting point to be developed for specifically the handling and storage of hydrogen. However, what exactly this looks like remains rather unknown as the pathway to a public serving hydrogen infrastructure is still in development. One thing known for sure is these companies working in this development will all need Fluoropolymer and PEEK products incorporated within these systems, however the final product looks. Fluoropolymer and PEEK materials offer many exceptional benefits that are perfectly matched to the challenges faced in the equipment architecture for a hydrogen fuel network.
PEEK and its formulations provide a unique combination and range of high performance properties – its structure (from molecular to macroscopic scales) contributes to high strength/toughness at extreme temperatures, low permeability, low friction, and high wear resistance. All of this is needed for seals, valves and packing when working with hydrogen.
PEEK and its formulations provide a unique combination of high performance properties:
- high strength/ toughness at extreme temperatures
- low permeability, low friction, and high wear resistance needed for seals, valves, and packings
- Retention of properties at cryogenic to high temperatures
- Lower weight and similar stiffness to some metals
- retention of properties in corrosive, contaminated service conditions.
- PEEK polymers can be formulated with additives to offer specific property improvements
- Specific low temperature (cryogenic) PEEK material option AF825
AFT and Cryogenic Storage
An important portion of the future hydrogen infrastructure will handle cryogenically cooled, liquified hydrogen. The denser cryogenic liquid has a greater concentration of hydrogen than the gas. Typically, in cryogenic sealing applications, materials like PCTFE and TFM are best suited. At cryogenic temperatures, stiffness and retention of mechanical physical properties at a range of temperatures from ambient to cryogenic are critical, however more recent research has shown that the coefficient of friction of these materials can change drastically at cryogenic temperatures.
In addition to common cryogenic materials, PEEK has been used in downstream liquid hydrogen applications for years at temperatures ranging from -196°C (-321°F) up to 260°C (500°F), retaining the capability of withstanding pressures as high as 207 MPa (30 000 psi). This makes PEEK materials a perfect match for compressors working in hydrogen service, which will be subject to this temperature range. This has firmly added PEEK as a real contender for critical seats and seals in hydrogen sealing applications. We're very much looking forward to bringing PEEK with us into a greener future.