Research on fundamental combustion physics, flame velocity and structure, pathways of emissions formation for hydrogen and variable blends of hydrogen, including ammonia

Use of natural gas mixtures with high hydrogen content still exhibits high NO_x pollutant emissions, thus requiring the implementation of appropriate combustion technologies in new or existing gas turbines, such as DLE, sequential combustion, EGR and micro-mixing approaches. Besides, although recent research has shown that partial decomposition of ammonia (after transportation) to a blend of ammonia/hydrogen/nitrogen can be an interesting solution, many fundamental aspects of ammonia/hydrogen flames are not yet known, and NO_x emissions are a concern too. Other potential not well-known hydrogen blends could show similar issues.

Proposals should address the following areas of R&I:

• Development/validation of chemical kinetics mechanisms for combustion of unconventional hydrogen blends also in different technological contexts, e.g. with and without exhaust gas recirculation, from atmospheric to industrially relevant pressures, giving special emphasis on NO_x and N₂O formation pathways especially for ammonia/hydrogen blends. Achieving an optimal balance between accuracy and complexity (i.e. computational cost in its use) should be considered as an important achievement;
• Numerical modelling and laboratory-scale experimental investigation of the conditions that ensure static (flashback and blow-out control) and dynamic (control of thermo-acoustic instabilities) stabilisation of premixed and non-premixed flames of unconventional, not well-known hydrogen blends while conserving low-emission performance, from atmospheric to industrially relevant pressures. The specific strategy that will be adopted to pursue the main goal should be clearly described in the proposal (e.g. fuel/air staging, fuel injection, blending etc.);
• Identification of real-time monitoring strategies of combustion, that can be reasonably implemented in gas turbines. The selected strategy should also come up with the definition of reliable and suitable indexes for the real-time identification of instability precursors.

In developing its concept, proposals are expected to address the following related aspects:

• To lower the environmental impact of the proposed solution (in particular, the level of pollution it will create and in general, the overall contribution to harden the climate emergency);
• To lower the barriers to the deployment of such technologies, including issues related to social acceptance and safety.

Proposals should address the validation of unconventional, not well-known hydrogen blends (like NH₃/H₂/N₂ blends ) combustion to TRL 4, presenting a robust research methodology and activities, establishing its technological feasibility. The methodology should include proper assessment of the technological feasibility, safety, and risk of using new blends in DLE gas turbines for power generation and transport applications, including environmental, social, and economic risk/benefit balance (e.g. evaluation of cost reduction and efficiency improvements vs consequences in case of accident). These aspects may provide ideas, experiences, technology contributions, knowledge, new approaches and skills.

Successful projects should provide supporting data, guidelines, and design tools for equipment manufacturers in combustion applications (mainly gas turbine).

Consortia are expected to include research and academic centres as well as gas turbine manufactures that can provide guidance and suggestions on the combustion technologies.

Proposals are expected to collaborate and explore synergies with projects supported under the topic “HORIZON-JTI-CLEANH2-2022-04-04: Dry Low NOx combustion of hydrogen-enriched fuels at high-pressure conditions for gas turbine applications”.

Activities are expected to start at TRL 2 and achieve TRL 4 by the end of the project - see General Annex B.

The JU estimates that an EU contribution of maximum EUR 3.00 million would allow these outcomes to be addressed appropriately.

The conditions related to this topic are provided in the chapter 2.2.3.2 of the Clean Hydrogen JU 2023 Annual Work Plan and in the General Annexes to the Horizon Europe Work Programme 2023–2024 which apply mutatis mutandis.