Storing Liquid Hydrogen for Zero-Emission Aviation
Airbus is making significant strides in developing liquid hydrogen storage tanks for its ZEROe concept aircraft, a promising technology for reducing aviation's climate impact. Several research and development facilities across Europe are working on this innovative solution.
The low volumetric energy density of hydrogen poses unique challenges. To address these, Airbus is focusing on both metallic and composite liquid hydrogen tanks. The key challenges include the large size and insulation requirements of cryogenic tanks, impact on aircraft aerodynamics and structure, and material challenges due to cryogenic temperatures and pressure cycling.
To tackle these problems, Airbus and partners have developed innovative solutions. These include using thermoplastic composites and bio-based resins for tank structure and fuselage components, optimised cryogenic tank designs, and extensive testing of proprietary cryogenic liquid hydrogen storage tanks.
The ZEDC in Spain will accelerate the development of composite liquid hydrogen tanks, while the ZEDCs in Nantes, France, and Bremen, Germany, will focus on metallic tanks for near-term commercial flight. Airbus' new ZEDCs will host multidisciplinary engineering teams to create innovative solutions that meet the demanding aerospace requirements.
Airbus is adapting existing hydrogen storage technology for its ZEROe concept aircraft. The new Airbus ZEDCs will be operational and ready for ground testing with the first fully functional cryogenic hydrogen tank during 2023, with flight testing starting in 2025.
When generated from renewable energy sources, hydrogen emits zero CO2 during flight, making it a promising solution for reducing aviation's carbon footprint. Hydrogen delivers approximately three times the energy per unit mass of conventional jet fuel, but its lower energy density requires larger, cryogenic tanks. However, by liquefying hydrogen at -253°C, its energy density increases, making four litres equivalent to one litre of standard jet fuel.
Storing hydrogen on-board an aircraft in its gaseous state would require approximately 3,000 litres for the same amount of energy as one litre of kerosene fuel. Pressurising hydrogen at 700 bars can reduce the required volume to six litres.
Airbus' involvement in Ariane has provided valuable knowledge on systems installation, cryogenic testing, fuel sloshing management, and inner tank construction. The company is also collaborating with industry partners on projects like the Multifunctional Fuselage Demonstrator (MFFD) to pioneer the use of thermoplastic composites in primary aerospace structures, crucial for hydrogen fuel tank integration.
Sources: [1] Airbus (2021). Airbus ZEROe: Pioneering hydrogen-powered flight. [Online]. Available: https://www.airbus.com/innovation/zero-emission-aircraft.html
[4] Airbus (2021). Airbus ZEROe: Hydrogen fuel tanks. [Online]. Available: https://www.airbus.com/innovation/zero-emission-aircraft/hydrogen-fuel-tanks.html
[5] Airbus (2021). Airbus ZEROe: A holistic approach to hydrogen-powered flight. [Online]. Available: https://www.airbus.com/innovation/zero-emission-aircraft/holistic-approach.html
- Airbus' ongoing collaborations with industry partners, such as the multidisciplinary engineering teams in the new ZEDCs and the Ariane project, will be instrumental in addressing material challenges, cryogenic testing, and fuel management, essential for the successful implementation of liquid hydrogen storage tanks in the aerospace industry.
- In the pursuit of developing sustainable aircraft to minimize aviation's climate impact, Airbus is exploring various sectors like technology, finance, and aerospace, as seen in their push for hydrogen-powered flight, the use of thermoplastic composites in primary structures, and partnerships with sectors like renewable energy and Ariane, ultimately aiming to revolutionize the finance and technology landscapes within the industry.
