Safe hydrogen injection management at network-wide level: towards European gas sector transition

To date, the approach taken to inject hydrogen in the gas networks is left to be defined on a local basis in terms of concentration threshold, locations and purity. This fragmentation could cause significant interoperability issues, particularly when the quantities of hydrogen injected into the gas network will be more widespread geographically and probably variable in time. The impact on gas transportation and distribution (T&D) network components (e.g. valves, fittings, reduction stations, etc) and on all end-users connected to the gas infrastructure, with respect to the nominal 100% hydrogen and transients in the blend compositions is not fully understood.

To address these gaps, it is vital to map European gas T&D infrastructure and interact with operators in order to collect information about materials, components, technology and their readiness for hydrogen blending. It is also vital to develop knowledge for localisation of hydrogen injection, managing concentration fluctuations for blends and a detailed understanding of the implications of repurposing pipes for hydrogen duty.

The need for protocols for inspection and monitoring emerges from the development of networks carrying new gases or gases for which they were not originally designed. Preventive measures (inspection) and solutions to mitigate the impact of hydrogen at component level are still at a low level of maturity or not yet fully adapted to the integration of hydrogen into networks.

Project results are expected to contribute to the following expected outcomes:

• Definition of methods, tools and technologies for multi-gas network management and quality tracking, including simulation, prediction and safe management of transients, in view of widespread hydrogen injection in a context of European-wide interoperability and gas market reform;
• Best practice guidelines for handling the safety of hydrogen in the natural gas infrastructure, managing the risks (with prevention and mitigation protocols) for guaranteeing the safe interoperability of gas transport at European level;
• Mapping and assessing T&D infrastructure components at European level to identify best available technologies, the hydrogen readiness of components, network technologies and monitoring protocols in order to steer stakeholders towards effective regulation and technical standards, network repurposing and modernisation investments.

Project results are expected to contribute to all of the following objectives of the Clean Hydrogen JU SRIA (especially for Pillar 2, Hydrogen Storage and Distribution –Sub Pillar: Hydrogen in the Natural Gas Grid, and for Cross-cutting issues - Area: Safety, Pre-Normative Research and Regulations, Codes and Standards):

• Development of technologies and materials to facilitate the transportation of hydrogen via the natural gas grid;
• Enable through research and demonstration activities the transportation of hydrogen through the natural gas grid either by blending or via repurposing to 100% hydrogen;
• Increase the level of safety of hydrogen technologies and applications;
• Support the development of RCS for hydrogen technologies and applications, with the focus on standards;
• Contribute to the SRIA KPIs for Safety, PNR & RCS, organising safety workshops (Targets: 2024 = 2 workshops/year, 2030 = 4 workshops/ year);
• Contribute to the SRIA KPIs for Safety, PNR & RCS, providing inputs for developing Standards, Technical Specifications, or Technical Reports at the international level (Targets: 2024 = 0.9 No/ project, 2030 = 1 No/ project).

This topic aims to define comprehensive technical information, standard protocols for the managing of a multi-gas network and give scientific-based evidence in order to help stakeholders towards the development of effective regulation and technical standards, network repurposing and modernisation investments.

The GERG CEN H2 PNR project^[1] has helped to define a comprehensive list of impacted standards and a gap analysis for managing these standards through targeted PNR, and the project should aim to interact with these identified priorities at CEN TC level where possible.

Proposals should also support the aims of the Hydrogen and Decarbonised Gas Market Package^[2] which provides the regulatory framework within which future gas networks will operate.

Proposals should address the management and control of transients of composition of natural gas and hydrogen mixtures for safe end use. In particular:

• Injection of hydrogen in existing gas grids can lead to a heterogeneous quality delivered to end-users. Quality variation should be predicted and controlled and injection strategies of hydrogen in the gas grid are needed.

Facing multiple production and injection points, complex grids, time-varying injection volumes and end-user demand volumes, the goal to predict and control gas quality in hydrogen blends could be addressed with a twofold approach. On one hand, by developing open modelling tools for gas network simulation, on the other hand, by identifying key technologies for quality tracking and the mitigation of quality variation in the natural gas network.

Solutions for the coordination of the hydrogen production and blending installations and their operations are required both from technical and regulatory points of view to guarantee quality control and to provide gas operators with the tools to manage a harmonised playing field for investors at EU level. Therefore, modelling should identify strategies for optimal injection points and gas network control, to evaluate pure or blended hydrogen injection strategies and to perform gas quality tracking and control. The project should analyse these issues in view of the intersectoral integration through power-to-hydrogen. Both gas distribution and transmission networks should be considered.

On the other hand, it is necessary to identify key technologies for quality tracking and the ones that are able to subsequently mitigate quality variation in the natural gas network, fully integrated with a dedicated ICT infrastructure for the digitalisation of the sector. Guidelines can also provide input for new technical norms that may spur innovation in selected network technologies for quality tracking and control.

Proposals should provide guidance to assist the injection of hydrogen in the gas infrastructure across Europe, consistently highlighting the new issues, the technical and administrative barriers and gaps by using a clear methodology that will give the basis to the definition of EU technical standards, which should include also the ICT protocols.

In addition, proposals are strongly encouraged to address the following activities:

• Analysis of delivered gas quality impacts on repurposed and new pipelines.

Proposals are expected to build on previous projects investigating the effects of hydrogen quality through repurposed pipelines (such as the Cadent Gas Hydrogen Grid to Vehicle project ^[3]), with a specific focus on the effect of the hydrogen presence (and its variation) on all the items of the networks (e.g. valves, fittings, sealants, reduction stations, etc).

In addition, proposals are encouraged to perform gas quality testing of real samples. The analysis obtained will be undertaken along the delivery chain from the industrially produced hydrogen to storage and transmission and distribution through to final appliances. On the one hand, the work will support European industry to confidently produce, transport and store hydrogen with no impact to the end-user due to gas quality issues. On the other hand, it will help in generating a methodology to set specific hydrogen acceptability and hydrogen variation limits in sections of the gas infrastructure, depending on the status of the existing infrastructure and the functional requirement of the connected appliances.

The results will support the further development and revision of a new EN standard for hydrogen quality in gas grids. It will also provide knowledge to develop new guidance on performing risk assessments for hydrogen-natural gas blends quality in gas grids.

• Analysis and inspection of infrastructure component behaviour in the presence of hydrogen.

Proposals are expected to build on the outputs of CEN H2 PNR (GERG) and other projects such as the HIGGS project ^[4]. Additionally, it is expected to cooperate with the project resulting from topic HORIZON-JTI-CLEANH2-2022 -02-01 which will be developing parallel testing protocols for metallic materials. A systemic analysis of the existing grid infrastructure is expected, shifting from single material compatibility to the evaluation of the fitness-for-purpose of components of the gas infrastructure.

Proposals are encouraged to develop a database of gas grid components (valves, fittings, gaskets, sealant, metering, odorisation, reduction stations, etc) behaviour in the presence of hydrogen correlated to the operating conditions of the networks and the materials that constitute them, assessing the compatibility of vintage and new gas infrastructures with hydrogen. The expected outcomes are therefore the mapping of components installed in European gas networks and the assessment of the compatibility of each single item. A ready-for-hydrogen ranking of all the existing items on the gas networks, together with the knowledge of the acceptability limits of end-user appliances, may be useful to define the best available network configurations for hydrogen blending management, different blending limits, priorities for modernisation and repurposing of existing assets, different safety requirements and protocols for the inspection (e.g. leak detection) and consequent management of risks. This should also be mapped with the quality and mitigation requirements for existing appliances (e.g. taken from the outcomes of projects such as THyGA ^[4]).

Based on the outcomes of the above activities proposals are expected to develop protocols for inspecting (in-line inspection and non-destructive testing tools) and monitoring the integrity of pipelines and other equipment exposed to hydrogen, for the detection of the leakages and the correlated countermeasures and offer innovative solutions for non-inspectable pipes, both at transmission and distribution level.

Proposals should identify and target the relevant standard(s) at the scope and activities should envisage links and synergies with existing platforms and/or projects as well as means of collaboration with similar activities ongoing internationally. Proposals are encouraged to include a formal standardisation body within the consortium.

Proposals are expected to contribute towards the activities of Mission Innovation 2.0 - Clean Hydrogen Mission. Cooperation with entities from Clean Hydrogen Mission member countries, which are neither EU Member States nor Horizon Europe Associated countries, is encouraged (see section 2.2.6.8 International Cooperation).

Activities are expected to start at TRL 3 and achieve TRL 6 by the end of the project. TRLs at the start and at the end of the project are not referred to the specific actions proposed in the scope, but to the whole set of actions proposed, that due to the wide scope and the interaction with the harmonisation and regulatory activities will vary from TRL 3 to TRL 6.

The conditions related to this topic are provided in the chapter 2.2.3.2 of the Clean Hydrogen JU 2022 Annual Work Plan and in the General Annexes to the Horizon Europe Work Programme 2021–2022 which apply mutatis mutandis.

[1]https://www.gerg.eu/project/hydrogen/

[2]https://ec.europa.eu/energy/topics/markets-and-consumers/market-legislation/hydrogen-and-decarbonised-gas-market-package_en

[3]https://smarter.energynetworks.org/projects/nia_cad0022

[4]https://www.clean-hydrogen.europa.eu/projects-repository_en

[5]https://www.clean-hydrogen.europa.eu/projects-repository_en