The issue of decarbonizing the energy system is one of the greatest challenges worldwide at the moment. The transition towards a hydrogen driven economy is globally gathering pace, and at a European level there are already several pilot projects to prove hydrogen technologies and their economic applicability. There is clear evidence that hydrogen is actively perceived from both industry and politics as being an important sustainable energy source in the future.

A key enabler within the hydrogen energy transition is the ability to safely and economically transport hydrogen. The use of pipelines is an obvious solution to this challenge, however hydrogen induced degradation of materials is acknowledged as one of the key challenges for the pipeline industry. There are thousands of kilometres of pipelines already transporting hydrogen gas, however almost all of these have been designed, built and operated in accordance with hydrogen specific codes. Re-purposing of existing natural gas pipelines will therefore imply different challenges.

EPRG recognise that extensive research has already been performed into the effects of hydrogen on materials. For example previous studies show that there are existing specific combinations of susceptible material, hydrogen concentration and stress level, which can lead to an accelerated fatigue crack growth rate. However this information has not to date been combined into one comprehensive study summarising the effects of gaseous hydrogen on pipeline materials.

This paper summarises the outcome of an EPRG sponsored literature study looking at the effects of hydrogen on pipeline materials, and potential mitigation strategies.