Today, the European multinational aerospace corporation, Airbus, has emphasized its goal of building the world’s first zero-emission commercial airplane by 2035, relying heavily on hydrogen.
This will necessitate a new strategy to fuel storage. Airbus is currently developing cutting-edge liquid hydrogen tanks to help usher in a new era of environmentally-friendly flight.
Hydrogen is one of the most promising solutions for reducing aviation’s climate effect. It emits no CO2 when it is produced using renewable energy sources. It provides roughly three times the energy per unit mass of ordinary jet fuel and more than 100 times the energy per unit mass of lithium-ion batteries.
However, storing hydrogen on an aircraft presents a number of difficulties. Hydrogen may have more energy per unit of mass than kerosene but less energy per unit of volume.
To obtain the same amount of energy as one liter of kerosene fuel at normal atmospheric pressure and ambient temperature, approximately 3,000 liters of gaseous hydrogen would be required.
Obviously, this is not possible in flight. One option is to pressurize the hydrogen to 700 bars, which is a method utilized in the automotive industry.
Cryogenic liquid hydrogen storage tanks are already in use in a variety of industries, including aerospace, which provides us with a clear understanding of the issues. For example, Airbus’ involvement with Ariane aided in developing knowledge in areas such as system installation, cryogenic testing, and fuel sloshing management, as well as how to construct the inner tank itself.
However, while there are certain similarities between space flight and aviation, there are also many significant distinctions. Commercial airplane hydrogen storage tanks would have to withstand around 20,000 take-offs and landings and would need to store the hydrogen in a liquid form for far longer than space rockets.
This may represent a huge improvement, but aircraft’s weight and volume are critical. To go further still, we can dial down the temperature to -253°C. That’s when hydrogen transforms itself from a gas to a liquid, increasing its energy density even more. Returning to our example, four liters of liquid hydrogen would be the equivalent of one liter of standard jet fuel.
Airbus is adapting and improving current hydrogen storage technology for aviation as part of its commitment to clean aerospace. Several new European research and development centers have recently started working on liquid hydrogen storage tanks for our ZEROe concept plane.
Liquid hydrogen tanks for commercial flights are expected to be metallic in the near future. Zero Emission Development Centers (ZEDCs) in Nantes, France, and Bremen, Germany, will follow this strategy.
The first fully functional cryogenic hydrogen tank is projected to be fully operational and available for ground testing in 2023, with flight testing beginning in 2025.
According to the Head of Engineering for LH2 Storage and Distribution at Airbus, David Butters noted that:
“Adapting cryogenic tank technology for commercial aircraft represents some major design and manufacturing challenges,”
“The new Airbus ZEDCs will host multidisciplinary @engineering teams to create innovative solutions that will meet demanding aerospace requirements.” He added.