TECNALIA evaluates materials to adapt gas networks for hydrogen

The CANDHy project continues to make significant progress towards ensuring the safe integration of green hydrogen into natural gas distribution networks

The CANDHy initiative is funded by the Clean Hydrogen Partnership, and is aimed at generating sound scientific data on the behaviour of non-ferrous metallic materials when exposed to mixtures of hydrogen and natural gas, and even 100 % hydrogen. The aim is to facilitate the adaptation of existing infrastructure to the needs of the energy transition in Europe, so as to achieve climate neutrality by 2050.

Decarbonisation of gas networks

The roll-out of green hydrogen as an energy carrier means that steps need to be taken to ensure that existing networks can operate without compromising their integrity. CANDHy tackles this challenge by:

• Assessing the hydrogen tolerance of materials such as cast iron, copper, brass, aluminium and other non-ferrous alloys that can be found in European networks.
• Simultaneously carrying out tests on independent platforms using harmonised methodologies, ensuring reliable and reproducible results.
• Developing pre-regulatory guidelines based on experimental data in order to support future updates of technical standards and regulations.

These efforts will make it possible for network operators to access validated, standardised information to plan the injection of hydrogen blends at low pressure (16 bar) in complete safety.

• As a first step, the consortium has completed a detailed inventory of non-ferrous materials used in gas networks in 29 European countries, together with a review of standards, codes and phenomena associated with hydrogen embrittlement.
• CANDHy has also defined test protocols for new and vintage materials, including conditions with H₂/NG blends up to 20% mol and tests with pure hydrogen.
• It is currently working on a model that will make it easier to understand the mechanisms of hydrogen embrittlement, and on developing pre-regulatory guidelines based on the results obtained.

TECNALIA: a key actor in materials compatibility

TECNALIA plays a key role in the consortium by providing experimental infrastructures, which have been adapted to carry out specific tests on the compatibility of materials with hydrogen.

Its contribution is particularly important in:

• The preparation and execution of pre-regulatory tests (dynamic and static tests and permeability analysis).
• The mechanical characterisation and analysis of materials subjected to different concentrations of hydrogen.
• The creation of a database of materials compatible with hydrogen, and collaboration on developing harmonised testing protocols that will form the basis for future European standardisation

TECNALIA’s involvement in CANDHy has not only strengthened its leadership in the hydrogen ecosystem, but has also directly helped to reduce economic and technical risks for distribution system operators (DSOs). By providing reproducible data and validated models, the project is transforming the current gas infrastructure into a flexible, sustainable network, thereby speeding up the transition to a decarbonised economy.

The project is coordinated by Fundación Hidrógeno Aragón (FHa) (the Aragon Hydrogen Foundation) and brings together key players in research, certification and network operations such as RINA, GRTgaz and TECNALIA, and is supported by the Clean Hydrogen Partnership, the European Union, Hydrogen Europe and Hydrogen Europe Research.