Transporting natural gas through pipelines has been shown to be safe and efficient for decades. However, decarbonizing the European industry and reducing carbon emissions will require a significant portion of the existing pipeline infrastructure to be used for transporting gaseous hydrogen under high pressure across the continent, from production sites to end users. The pipelines, originally designed for natural gas, are not considered H2-ready, and Transmission System Operators must demonstrate their compatibility with hydrogen. The existing standards, such as ASME B31.12 are often viewed as overly conservative and not conducive to the development of pure hydrogen networks.
PilgrHYm is an ambitious R&D project that seeks to develop a pre-normative framework to support the development of a European standard. The project aims to conduct a comprehensive testing program on small-scale laboratory specimens, focusing on 8 base materials, 2 welds, and 2 heat-affected zones that are representative of the EU gas grids. These specimens will be selected after a thorough review by TSOs to address safety concerns, lack of regulations, codes, and standards, as well as research gaps related to the compatibility of current pipelines with hydrogen. PilgrHYm's ultimate goal is to provide quantified data on more than 70% of the EU grid and refine existing norms, codes, and standards by reducing over-conservatism and ensuring the safety and reliability of flaw assessment methodologies.
To reach the previously stated goals, PilgrHYm has established 7 technical and non-technical specific objectives (SO), interconnected with the project's results, key performance indicators and work packages.
- SO1: Develop a database of material characterization testing on representative steel grades of the EU gas grids, including tensile strength, fracture toughness and fatigue crack growth (FCG) properties.
- SO2: Establish a harmonized testing protocol to support the repurposing of natural gas lines to hydrogen.
- SO3: Develop a numerical modelling approach for simulating and predicting hydrogen assisted fracture and fatigue.
- SO4: Optimize a more realistic FCGR (Fatigue Crack Growth Rate) master curve for fitness-for-service assessment purpose, in particular for low ΔK values corresponding to the actual operating domain of the EU gas grids.
- SO5: Identify existing and/or innovative technologies for mitigation compatible with operational constraints.
- SO6: Engage with stakeholders to ensure cooperation and awareness.
- SO7: Facilitate the adoption and exploitation of PilgrHYm results by the academic community, technology developers and end-users.
The results of PilgrHYm will serve as the baseline for a harmonized European solution. This project represents a significant step forward in the development of a comprehensive European standard for transporting hydrogen through pipelines and will be instrumental in the successful decarbonization of the European industry and reducing carbon emissions.
