Guide for Storing Liquid Hydrogen for Eco-Friendly Aircraft Propulsion
In an ambitious move towards a greener future, Airbus is innovating on liquid hydrogen tanks for commercial flights. The company's ZEDCs (ZEROe Development Centres) are at the forefront of this development, focusing on cryogenic liquid hydrogen fuel systems and structural components for zero-emission aircraft.
The ZEDCs are designed to improve cryogenic storage and fuel system performance. One of the key strategies is to replace the heavy outer jackets on hydrogen fuel tanks with lighter, high-performance materials. This not only reduces aircraft weight but also simplifies manufacturing, addressing key challenges of hydrogen storage such as maintaining cryogenic temperatures and minimizing tank weight.
The ZEDC Phase 2 is building on the success of Phase 1, enabling further experimental work on cryogenic liquid hydrogen tanks and fuel system integration under realistic operational conditions. The aim is to reduce the overall aircraft weight penalty from the bulky, insulated hydrogen tanks, thereby improving aircraft efficiency and range.
The use of liquid hydrogen instead of gaseous hydrogen allows for a reduction in tank size. However, it requires advanced cryogenic fuel tanks. These tanks consist of an inner and outer tank with a vacuum in between, and a specific material like MLI (Multi-Layer Insulation) to minimize heat transfer by radiation.
Airbus' efforts are part of a £35 million investment in the ZEDC program, underpinning the company's goal of making zero-emission commercial aircraft a reality by 2035. The new Airbus ZEDCs will host multidisciplinary engineering teams to create innovative solutions. The ZEDCs in Nantes, France, and Bremen, in northern Germany, will pursue metallic tank development.
Flight testing for the hydrogen tank is expected to start in 2025, and all ZEDCs are expected to be fully operational and ready for ground testing with the first fully functional cryogenic hydrogen tank during 2023.
Hydrogen, with its promise to reduce aviation's climate impact, is a promising technology. It delivers approximately three times the energy per unit mass of conventional jet fuel. However, adapting cryogenic tank technology for commercial aircraft presents major design and manufacturing challenges.
Airbus is addressing these challenges by adapting hydrogen storage technology for its ZEROe concept aircraft. The company's experience with Ariane has provided valuable knowledge on systems installation, cryogenic testing, fuel sloshing management, and building inner tanks.
Safety requirements for hydrogen storage tanks for commercial aircraft are different than for space launchers, as they would have to endure approximately 20,000 take-offs and landings and keep the hydrogen in the liquid state for longer. When generated from renewable energy sources, hydrogen emits zero CO2 during flight.
Cryogenic liquid hydrogen storage tanks are used in several industries, including aerospace. Airbus will accelerate the development of composite materials at its new ZEDC in Spain and its composite research centre in Stade, Germany. Several new research and development facilities across Europe are working on liquid hydrogen storage tanks for the ZEROe concept aircraft.
In summary, Airbus' ZEDCs are advancing cryogenic liquid hydrogen storage technologies through lightweight material replacement and comprehensive testing infrastructure to improve fuel tank performance, weight, and integration—critical barriers for hydrogen-powered zero-emission aircraft. The company's investment in this technology is a significant step towards a more sustainable aviation industry.
The ZEDCs, focusing on cryogenic liquid hydrogen fuel systems, aim to improve aircraft efficiency and range by replacing heavy outer jackets on hydrogen fuel tanks with lighter, high-performance materials.
Airbus' efforts in the ZEDC program, such as the development of lightweight materials and comprehensive testing infrastructure, are critical steps towards advancing cryogenic liquid hydrogen storage technologies for zero-emission aircraft, addressing challenges in hydrogen storage like minimizing tank weight and maintaining cryogenic temperatures.
