Airport-Level DemonstRatIon of Ground refuelling of Liquid Hydrogen for AviaTion

Project Information

ALRIGH2T

Grant agreement ID: 101138105

DOI

10.3030/101138105

EC signature date 15 December 2023

Start date 1 January 2024

End date 31 December 2027

Funded under

• Climate, Energy and Mobility

Total cost

€ 12 920 388,00

EU contribution

€ 9 999 720,01

Coordinated by

AGENZIA NAZIONALE PER LE NUOVE TECNOLOGIE, L'ENERGIA E LO SVILUPPO ECONOMICO SOSTENIBILE
Italy

Periodic Reporting for period 1 - ALRIGH2T (Airport-Level DemonstRatIon of Ground refuelling of Liquid Hydrogen for AviaTion)

Reporting period: 2024-01-01 to 2025-06-30

Summary of the context and overall objectives of the project

Aviation is a cornerstone of global connectivity but also a sector under increasing pressure to decarbonize. Liquid green hydrogen (LH2) is one of the most promising alternatives. It combines high energy density with zero CO2 emissions at the point of use. Today, aircraft manufacturers are developing concepts of new aircrafts able to use this new fuel, but airports lack the infrastructure, operational protocols, and regulatory frameworks needed to deploy it safely and efficiently at scale.

ALRIGH2T directly addresses this gap by pioneering the first airport-level demonstrations of LH2 refuelling for aviation in Europe. Demonstrations will take place at two major airports, Milan Malpensa and Paris, to validate the introduction of hydrogen in a real airport environment under different operational contexts and ensure broad applicability. The overall objectives of ALRIGH2T are to:
- To define the technical requirements and boundary conditions for safe, feasible, and efficient LH2 refuelling in European airports.
- To develop and validate innovative components, including a centrifugal pump, an instrumented tank, advanced sensors, and a digital twin model of the refuelling process that, once validated experimentally in the demo, will allow broader investigation of all the variables involved and predictions on future evolution.
- To demonstrate both direct LH2 refuelling and GH2 end-to-end logistics and supply chain solutions at Milan Malpensa and Paris airports, with technologies reaching TRL 6 by 2027.
- To establish regulatory, safety, and environmental frameworks that will help future certification and standardization of LH2 and GH2 operations.
- To share project results broadly, engage with stakeholders and EU initiatives, and ensure a clear pathway to industrial uptake and long-term impact.
The pathway to impact follows a stepwise approach. First, demand, feasibility, and techno-economic aspects are assessed. Next, critical components, logistics processes, and virtual models are designed, built, and tested. Finally, integrated demonstrations at airports provide the evidence needed for validation and future scale-up. This ensures that results are not isolated prototypes but practical solutions that will be able to foster regulatory approval and operational deployment.
ALRIGH2T will prepare the way to enable airports to refuel hydrogen-powered aircraft, support the entry into service of zero-emission aviation by 2035, and accelerate the decarbonization of airport ground operations. Beyond aviation, advances in cryogenic hydrogen management, logistics modelling, safety analysis, and digital simulation will benefit other hydrogen-intensive sectors.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In the first reporting period (M1–M18), the project moved from preparatory studies to the design, modelling, and initial testing of LH2 refuelling technologies, supported by demand and safety assessments.Work started with the definition of technical requirements and boundary conditions. Market and demand models for hydrogen-powered aircraft operations were developed for Paris and Milan airports, examining existing short and medium haul commercial routes and providing forecasts of introduction of LH2 aircrafts, selecting passenger routes and providing future associated LH2 needs. These results feed directly into techno-economic analyses of future supply chain options. On the technological side, progress was achieved in the development of critical refuelling components. The work on a prototype for a centrifugal LH2 pump was advanced, supported by detailed simulations of the refuelling process and HAZOP studies. These revealed the need for design adaptations and safety enhancements to guarantee stable operation under varying conditions and avoid cavitation, leading to the need for an updated engineering plan of system components, piping layouts, instrumentation and control logic.

In parallel, an instrumented LH2 storage tank was designed and prepared for production. A comprehensive set of sensors and control systems was identified, number and positioning of the sensors tested and validated to avoid excess heat introduction while recovering the maximum amount of experimental data and integrated into the design. To support this work, digital twin models of the tank and refuelling process were developed, combining high-fidelity simulations with reduced-order models. First results demonstrated good agreement with expected physical behaviour, paving the way for validation with experimental data. Preparations also began for cryogenic testing using liquid nitrogen as a safe substitute for hydrogen in early trials.
Demonstration activities at Milan Malpensa were launched. A preliminary test layout and matrix were drafted, and operational and safety requirements were defined to support the future SANDBOX procedure with the Italian aviation authority. The need for an intermediate control station was identified to ensure accurate transfer of LH2 during the demonstration enhancing the accuracy and reproducibility of the measured data and subsequent validation of the digital twin. In addition, concerning the introduction of GH2, initial studies were conducted for the integration of telemetry sensors into hydrogen-powered ground service vehicles. A first synthesis of existing regulations was completed, hazard analyses were initiated, and preliminary risk assessments were produced to guide system design and future demonstration authorizations.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The project is still in an early phase, with no final results yet, but first advances are already moving beyond the state of the art. Demand and feasibility models for hydrogen-powered aircraft at Milan and Paris airports have been developed, providing a new evidence base for airport-scale hydrogen planning and indications on modifications needed on airport masterplans. Novel engineering work on a high flux centrifugal LH2 pump and an instrumented storage tank introduced design adaptations to ensure safe, stable operation, supported by digital twin models of the refuelling process. Early safety and regulatory reviews identified gaps in current frameworks, critical for future certification. To reach full impact, further large-scale demonstrations, continued research on safety and reliability, investment in infrastructure and logistics, and harmonized European standards will be needed.

ALRIGH2T_Overall_Concept