Hydrogen admixtures in natural gas domestic and commercial end uses

Research is required to identify and verify the impacts of continuous and time-varying supplies of H2NG blends on the combustion characteristics (flame speed and shape, temperature, emissivity, emissions) of appliances together with the potential impacts on appliance safety, efficiency, lifetime and environmental performance (e.g. NOx emissions). Results from previous and ongoing national and EU projects should be included (e.g. NaturalHy, GASQUAL, HIPS-NET, DOMHYDRO, GRHYD, HyDeploy, etc.) and their transferability evaluated.

Low, medium and high hydrogen concentrations in natural gas should be investigated:

• Low = <10% Vol.
• Medium = 10-30% Vol.
• High = 30-60% Vol.

The following activities should be undertaken, by means of desk research supported by an integrated experimental programme, and consider a wide range of appliances and hydrogen concentrations:

• Evaluate the existing end-use stock and new appliances with respect to their sensitivity to hydrogen concentration. Existing knowledge should be collated, testing procedures defined and testing undertaken both in relation to the existing EU stock of installed (domestic and commercial) appliances and to new gas technologies (e.g. micro-cogeneration, gas heat pumps, space heaters, fuel cells). The experimental procedures should be chosen to represent as far as possible real operative conditions (e.g. full components should be preferred to downsized laboratory prototypes). Validated accelerated stress testing should be performed, considering gas quality fluctuations and changes in environmental conditions. In some cases, in order to reduce testing costs, testing at the highest hydrogen concentration values may be ignored provided that a reasonable assessment can be made by modelling;
• Evaluate mitigation solutions to widen the acceptance of appliances to higher hydrogen concentrations. Existing combustion controls designed for natural gas quality variation are not necessarily suited for working with H2NG blends, so mitigation solutions should be determined and their technical feasibility verified. The work involving testing and/or modelling should cover hardware (combustions controls) for new or existing appliances (retrofit) and if relevant on site adjustment procedures. Burner modifications and other design changes should be identified, including possible simple actions to remedy any problems preventing the adoption of higher hydrogen concentrations. Tests should cover the main segment of the domestic and commercial appliance market and give priority to appliances that have been shown to be sensitive to hydrogen concentration and include long term testing. Where possible, appliance manufacturers should be involved;
• Identify new test methods /test gases for the certification of domestic and commercial appliances (falling under the Gas Appliances Regulation). In the future, gas burning appliances will have to be tested with H2NG specific test procedures and test gases to enable their certification, a prerequisite for the use of H2NG blends.

The tests should cover the impact on safety, efficiency, reliability, lifetime (for small domestic appliances only), CO, NOx and other possible impacts.

The combustion parameters Wobbe index, methane number, laminar flame speed and flame temperature are among the main parameters that should be considered in the investigation. Testing should be performed with different compositions of natural gas combined with different hydrogen concentrations. Temporal fluctuations in the concentration of hydrogen should also be studied. Gas of lower calorific value (L gas) is not considered in scope (due to its declining use).

It is expected that the consortium will interact with manufacturers, gas consumers and gas industry .

It is expected that the project will contribute towards the objectives and activities of the Hydrogen Innovation Challenge (as detailed under section 3.2.G. International cooperation). Promoting international collaboration beyond EU Member States and H2020 Associated Countries is therefore strongly encouraged.

Any safety-related event that may occur during execution of the project shall be reported to the European Commission's Joint Research Centre (JRC) dedicated mailbox JRC-PTT-H2SAFETY@ec.europa.eu, which manages the European hydrogen safety reference database, HIAD and the Hydrogen Event and Lessons LEarNed database, HELLEN.

Test activities should collaborate and use the protocols developed by the JRC Harmonisation Roadmap (see section 3.2.B ""Collaboration with JRC – Rolling Plan 2019""), in order to benchmark performance of components and allow for comparison across different projects.

The FCH 2 JU considers that proposals requesting a contribution of EUR 2.5 million would allow the specific challenges to be addressed appropriately. Nonetheless, this does not preclude submission and selection of proposals requesting other amounts.

A maximum of 1 project may be funded under this topic.

Expected duration: 3 years.

Injecting hydrogen admixtures into the natural gas network can contribute significantly to solving the problem of transporting and storing surplus electricity generated from renewable resources. There are, however, a number of challenges to operate safely with hydrogen admixtures (H2NG blends) for the existing gas infrastructure and end use equipment. In order to establish a European understanding of an acceptable hydrogen concentration in the natural gas system, a number of knowledge gaps need to be filled. The addition of hydrogen to natural gas influences gas properties and therefore the performance and safe operation of existing applications (including industrial gas turbines, industrial burners and residential burners). Domestic and commercial users are generally “passive” users of their gas appliances and they are not able themselves to intervene with the appliance (e.g. to counterbalance the effect of a gas change). Conversely, industrial users have more possibilities to intervene and retrofit/develop integrated mitigation solutions. Therefore, domestic and commercial users need to be addressed differently from industrial ones and this topic focuses exclusively on domestic and commercial applications.

Power-to-gas systems injecting admixtures of 2 vol% have been widely demonstrated, further demonstrations of up to 20 vol% (e.g. GRHYD, HyDeploy) are underway and have already shown that such systems can operate to provide grid services and absorb surplus renewables: already 10 vol% is permissible in some parts of the natural gas system, while a 2 vol% limit must be applied close to CNG refuelling stations. There is however a need to define a clear vision at EU level of the admissible hydrogen percentage for use in domestic and commercial applications. In addition, there is a need to identify the RCS needs for progressively enhancing the admissible hydrogen concentration in the gas system. CEN/TC 238, which is in charge of test gases for gas appliances and of defining gas appliance categories, has expressed the need for this PreNormative Research, PNR in view of the revision of EN 437 (the key transverse standard used for the testing required for the regulatory certification of gas appliances).

The project will ensure that the safe operation of existing and future gas appliances and applications is not jeopardized by the supply of H2NG instead of the natural gas composition range for which they have been designed and certified, and identify categories of existing appliances and equipment that would need to be replaced as the hydrogen concentration is increased. The expected impacts of the project include:

• Establishing what concentration hydrogen admixture can be implemented in the domestic and commercial sector without changing the existing certification of appliances;
• Establishing how the existing certification shall be modified to allow higher concentrations, including the related additional costs and the required changes to common gas burners;
• Recommendations for revision of EN or ISO standards or drafting of new standards based on PNR results and a review of the existing testing methods;
• Improved knowledge on the effect of H2NG on common burner types including necessary adjustments and design changes. This will help the industry to bring on the market appliances that will accept H2NG.

Type of action: Research and Innovation Action

The conditions related to this topic are provided in the chapter 3.3 and in the General Annexes to the Horizon 2020 Work Programme 2018– 2020 which apply mutatis mutandis.