Challenge N°5

Protect GRTgaz’s steel networks from the effects of hydrogen


Strongly involved in the energy transition, GRTgaz is seeking innovative solutions allowing it to facilitate the injection of hydrogen into its networks.


In the long term, hydrogen could have an increasingly important place in the gas transmission networks.


However, hydrogen, due to its physical characteristics and in particular that related to its very small molecule size, results in a migration in C-Mn (Carbon manganese) steel and irreversible accelerated ageing of the metal structure. It then becomes less malleable. GRTgaz is seeking an innovative solution to preserve the integrity of the interior surfaces of its networks made up of ferritic C-Mn steels, in order to prevent the migration of the H2 molecule into the steel.


From a metallurgical point of view, how to protect the steels making up the natural gas transmission networks from injected hydrogen so as to preserve their ductility?


– Difficult access to the steel surfaces in question: The GRTgaz network is mostly buried. Access to the interior surfaces of these buried pipes is complex, but possible, taking advantage for example of inspection campaigns implemented by GRTgaz (insertion of instrumented pistons or crawlers to check the integrity of the pipes). It would therefore be possible to intervene on the network.


– Reuse of existing networks, made up of DN150 tubes (L245 steel according to the NF EN ISO 3183 standard or equivalent) and of DN1200 tubes (L485M steel).


The solution sought by GRTgaz must:


– preserve the mechanical properties of the steels over time when they are subject to a greater concentration of hydrogen,

– ensure that the integrity of GRTgaz’s buried networks is preserved, while allowing the transmission of new gases.


GRTgaz wishes to find solutions for the passivation of the interior surfaces of the GRTgaz’s networks made up of ferritic C-Mn steels: the proposed solutions will either be for:


– a surface treatment or coating (shielding slowing down the permeation of the hydrogen), and how to apply it in the pipeline on the inner surface of the pipeline,

– or a product inhibiting the action of H2 (encapsulation, inhibitor, etc.).

Issues for GRTgaz

Financial: ensuring the durability of GRTgaz’s activities and the enhancement of its assets

Security: preserve the integrity of the facilities

Other: Strengthen the role of GRTgaz as a leader of the energy transition

Volumes / Time scales of the need

– Volumes: several hundreds of kilometres of pipelines


– Planned schedule:


 >  Development and testing: 2018 to 2020

 >  Deployment: between 2020 and 2030

Value outlooks for winners:

– Co-develop potential solutions in partnership with GRTgaz,

– Obtain the financing of solutions to develop or the financing of patents to be registered,

– Use the facilities of GRTgaz’s R&D centre (RICE) to develop and test the innovations,

– Be an actor of the Energy Transition, alongside GRTgaz;

Closing date: 15/10/2018