[ aviation ]
density . These fuel cells can generate more than 1 MW for each power pod .
More recently , testing of hydrogen-fired jet engines has taken place , with Rolls Royce and Easyjet confirming successful land-based firing of an AE 2100-A regional jet engine on a test bed in 2022 .
Hydrogen-fuelled drone
And aviation CO 2 emissions are rising faster than other transport sectors . With this context , the imperative to defossilise the aviation sector becomes clear .
Green hydrogen can be produced from renewable electrical power . This clean energy vector may unlock the key to sustainability in the aviation sector .
Power for propulsion
Long-mission duration drones were the first major application of hydrogen for aviation . Agricultural crop surveillance , gas pipeline condition monitoring , and the military have all deployed hydrogen-fuelled drones .
Compressed gaseous hydrogen stored in a lightweight Type 4 composite cylinder can flow through a fuel cell mounted on the drone . This can achieve a significantly longer range than a battery-powered drone with a similar payload .
Held back by the force of gravity
For land-based fuel storage and use , the volume of the fuel is often more important than its mass . For example , at a crude oil storage terminal , the mass of the fuel is of little consequence since it is borne by the land on which each storage tank sits .
In aviation , both the volumetric and gravimetric energy density are of critical importance . In a commercial aircraft , volumetric density plays a role since space must be available for fare-paying passengers .
Both liquid and gaseous hydrogen have a remarkably high gravimetric energy density . This alone puts them in the running as prime aviation fuel candidates . However , the fuel alone is not the only consideration .
The total mass of the fuel and its container is critical when benchmarking fuels . On this basis , the efficiency of traditional hydrogen storage is very poor , with less than 1 % of the weight of a
The first wave of hydrogen-fuelled aircraft were turboprop aircraft with powerful fuel cells to drive the propellors . Airbus , Zero Avia , Ruixiang , H2FLY , Sirius Jet , and Pipistrel have all experimented in this way .
High-temperature PEM fuel cells are currently favoured for aviation , due to their high power
Cryogenic liquid hydrogen storage tanks
Hydrogen Tech World | Issue 17 | August 2024 35