Fewer gas explosions: graphene polymers for the hydrogen economy

Graphene Flagship partner Graphmatech is creating thermoplastic masterbatches containing graphene – and these have significant applications for hydrogen storage and hydrogen transportation.

There is growing excitement over graphene among those working to store and transport hydrogen. Hydrogen promises to be a key player in transitioning towards greener economies – yet it can be difficult to contain cost-effectively.

Enter graphene. With distinctive properties including high ‘barrier performance’, or impermeability, and being extremely conductive, this nanomaterial is well-placed to be used in manufacturing new composite materials that could help store and transport hydrogen safely and effectively.

Recognising this potential, Graphene Flagship partner Graphmatech AB has been developing thermoplastic masterbatches carrying graphene, specifically for use in contexts where these masterbatches will be employed to manufacture products such as pressure vessel liners for hydrogen storage. Graphmatech is a Swedish materials technology company that invents, develops, and sells graphene-based materials.

Graphmatech representatives Niclas Westerlund and Torkel Nord Bjärneman noted that the company’s new high-density polyethylene (HDPE) masterbatch has strong potential to be useful within the plastics industry.

“Hydrogen is known to be difficult to store and transport as the molecule tends to escape through the materials used, hence leaking out into the atmosphere,” said Niclas Westerlund, Account Manager at Graphmatech.

“HDPE is commonly used as the gas barrier layer for Type IV pressure vessels – but permeation is an issue. This means that many customers use polyamide; however, this material is more expensive and can be harder to process than polyethylene.”

“We are excited to have discovered that when we mix graphene into virgin polyethylene and other plastics, we make these materials less permeable, amongst other improvements. This will open new possibilities to create products integral to the hydrogen economy,” said Torkel Nord Bjärneman, Business Development Manager at Graphmatech.

Graphmatech has been working with industrial partner ST BlowMoulding to test the uses of nanotechnologies in the blow moulding industry – blow moulding being the manufacturing process for forming hollow plastic parts, such as liners for Type IV pressure vessels.

The ST BlowMoulding team are well aware of the challenges involved in manufacturing high-quality liners that are impermeable to gaseous substances such as hydrogen. As part of their ongoing commitment to staying updated about innovations and the needs of the market, they have consequently entered into collaboration with Graphmatech with enthusiasm.

Marco Solinas, Global Product Manager at ST BlowMoulding, emphasised the value not only of graphene’s barrier properties, but also of its conductivity.

“Ensuring that gases such as hydrogen are stored and transported safely and effectively is a crucial concern – and it is exciting to see that graphene could help in this space,” said Marco Solinas.

“Increasingly, many customers producing containers for chemicals want their plastics to be conductive. This is because non-conductive plastic containers can build up electro-static charges and these sometimes result in a spark, which may lead to an explosion if the plastic container is in an environment containing flammable gases or powders.”

“Yet by using a conductive material like graphene in the outer layer of such a container, we can prevent this risk. Additives based on silver chemical compounds are currently being used by manufacturers for this purpose; however, graphene is a significant competitor to those expensive additives and could potentially also be most cost-effective long-term.”

With all of this in mind, graphene’s growing presence in the hydrogen economy is something to celebrate. The future looks bright.

You can learn more about Graphmatech and ST BlowMoulding on their respective websites: https://graphmatech.com/about-us/and https://www.st-blowmoulding.com/.