Polymers & Composites for Hydrogen Economy

To qualify their EGF-PE Thermoplastic Composite Pipes for H2 service, Strohm performed series of exposure testing to demonstrate the chemical resistance of the EGF-PE and quantify physical effects caused by the absorbed H2.

Initial test results however differed from what was expected.

An in-depth investigation of the obtained results and even more the applied standard method of composite testing led to some very interesting findings.

These findings will be discussed, and recommendations will be given what measures can be taken to obtain representative results from exposure experiments.

Un-reinforced thermoplastic pipes are known to suffer from Rapid Crack Propagation (RCP) in which cracks of several hundred feet can form in a fraction of a second. RCP occurs where the crack or fracture tip propagates faster than the decompression wave, this allows the crack to “out run” the depressurisation. Spoolable composite pipes in many ways are analogous to pipes with continuous crack arrestors over the pipe body. This presentation will discuss resistance of spoolable composite pipes to this failure mode in Hydrogen.

This presentation will summarise the main challenges and current solutions available to us, including chemical and physical effects. It will also provide an overview of current test standards, and practical issues relating to testing – laboratory vs ‘real world. 

The talk will discuss the use of polymers and polymer composites in high value hydrogen applications and will focus on the material measurements requirements and current challenges when it comes to approving products for use in highly regulated industry sectors.

Applying laboratory scale cryogenic composite knowledge to real world applications requires a significant step change in understanding. This presentation will introduce our approach to solving this, whilst highlighting knowledge gaps and areas requiring further work.

Some semicrystalline polymers have excellent hydrogen barrier properties and are suitable as liners in hydrogen tanks and pipelines. In this presentation I will summarise the results of an ongoing research project aimed at developing multiscale models and collecting data in commercial semicrystalline polymers such as high-density polyethylene and polyamides. This approach provides a deeper understanding of the hydrogen barrier mechanism in solids and can be transferred to other complex materials such as composites.

A key issue holding back the technology for cryogenic LH2 storage is that hydrogen permeability through composite materials at cryogenic temperatures is relatively unknown for many composite materials, with many test houses unable to reach cryogenic temperatures and a degree of variability between existing datasets.

The presentation highlights the challenges involved in developing a system capable of precise measurements under extreme conditions, the capability of CHyPr (Cryogenic Hydrogen Permeation rig) and discussing the initial analysis of permeation behaviours in composite and polymer materials.

Atom probe tomography (APT) applications in hydrogen detection have mainly been aimed towards bulk metals with deuterium based liquid or gas charging and cryogenic sample preparation used to minimize hydrogen mobility.

Charging of site specific samples prepared by Focused Ion Beam containing specific nanoscale features is also now possible.

In this presentation, the current state of APT hydrogen analysis with relation to polymers will be discussed along with developments in protocols for the APT analysis of hydrogen species in model polymer nanocomposite systems.

Since 2022, NCC has been a development partner of project RACHEL (Robustly Achievable Combustion of Hydrogen Engine Layout), a research project aimed at developing the technologies and architectures to deliver a hydrogen-fuelled gas combustion engine.

Focusing on hydrogen pressure vessels, this presentation discusses the challenges of the application and how NCC are addressing them.

This talk will provide an overview on our experimental (tomography, permeability measurements) and modelling (micromechanics, fracture mechanics) work of composite laminates in high-pressure vessels and linerless cryogenic tanks.

Particular focus will be on the effects of variation in fibre volume fraction, porosity, and layer thickness in different areas of the high-pressure tanks, and the effects of ply thickness, interactions between damage in adjacent plies, and variability in mechanical properties in cryogenic tanks.