Integrity and safety of repurposed hydrogen pipelines in the European Union

The European Commission recognises hydrogen as an important chemical feedstock and energy carrier that could help decarbonise hard-to-abate sectors, such as heavy industry and heavy-duty transport. The development of a comprehensive hydrogen infrastructure in the European Union is required to bridge the gap between hydrogen supply and demand. One possibility to accelerate the establishment of a hydrogen transmission network is to repurpose part of the existing natural gas infrastructure for the transport of hydrogen, in addition to new constructions. Several projects are already planned to establish this infrastructure. In this frame, the effects of gaseous hydrogen on pipeline steel materials have been reviewed, and the implications for the integrity and safety of repurposed natural gas pipelines for hydrogen transport assessed. It was found that hydrogen exposure notably reduces the ductility and fracture toughness of steel materials and increases fatigue crack growth rates. These changes in material properties may have implications on the behaviour of defects found in the existing natural gas infrastructure, and may lead to the need for update of the pipeline inspection and integrity management practices. From a safety perspective, the safety protocols, emergency response plans, and risk assessment methodologies may need to be revised to account for the distinctive properties of hydrogen in comparison to natural gas, e.g. flammability range, ignition energy, buoyancy etc. Knowledge of past gas pipeline incidents is of interest in that regard to better understand the future behaviour of the hydrogen gas grid. The incident history from the natural gas transmission sector in Europe, and from hydrogen pipelines worldwide, has been compiled using the data available from the European Gas Pipeline Incident Data Group (EGIG) and from the Hydrogen Incidents and Accidents Database (HIAD). Their analysis provides valuable insight on the main threats to pipeline integrity and safety.

SMEDBERG Erik;  PITOIS Aurelien;  KLEINE Remi;  ACOSTA IBORRA Beatriz;  MORETTO Pietro; 

2025-10-27

HySafe

JRC141992

979-12-243-0274-2 (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC141992,