UCF leads project to develop zero-carbon jet engines

The University of Central Florida (UCF) is developing technology expected to make airplane engines emission free.

UCF evaluated their innovation, aiming to make aviation fuel green and create engines and fueling systems that integrate into current airport infrastructure.

“We don’t want to create something that will be too cumbersome and expensive to implement,” says lead investigator and UCF Engineering Professor Jay Kapat. “If we want people to adopt this green tech, it needs to be scalable. To adopt hydrogen, for example, we can’t expect every airport to set up large cryogenic liquid hydrogen systems like Kennedy Space Center. That’s unreasonable.”

With this practical approach, Kapat put together a team of experts from UCF, Georgia Tech, and Purdue and with industry experts from Boeing, General Electric, ANSYS, Southwest Research Institute, and the Greater Orlando Aviation Authority. The team landed a $10 million, 5-year NASA University Leadership Initiative grant.

“We have a good concept,” Kapat says. “And by having our partners in industry we know we’ll fine tune and be ready for technology transition, so we can provide a greener future for our children.”

Kapat and his colleagues propose using liquid ammonia (NH₃) as the fuel for aircraft which, upon combustion, will produce harmless green emissions while providing enough power to keep the aircraft aloft. At high altitudes, ammonia is naturally liquid which limits special handling.

Ammonia will be the hydrogen carrier, which will be catalytically cracked to release nitrogen and hydrogen. The hydrogen will be burned in the onboard combustors (inside the engine) to provide the power. Airports and aircraft are expected to store the NH₃ in fuel tanks. Excess NH₃ will then be used to catalytically reduce any NOx left in the exhaust, converting it to nitrogen and water.

The conversion process also provides cooling to keep engines from overheating and burning out for better performance and efficiency. Engine exhaust heat converts back to electricity for onboard use, reducing power draw from the core engines.

The team also is developing new components for jet engines to be used in conjunction with the new fuel. The team is using the 737-8 class for a baseline as it represents nearly a quarter of all commercial aircraft, according to Boeing.