The US Department of Energy (DoE) has chosen Pratt & Whitney to develop a new hydrogen propulsion technology for commercial aircraft as part of the DoE’s Advanced Research Projects Agency-Energy (ARPA-E) initiative.

For the next generation of single-aisle aircraft, the HySIITE (Hydrogen Steam Injected, Inter-Cooled Turbine Engine) project will use liquid hydrogen combustion and water vapor recovery to achieve zero in-flight CO2 emissions while reducing nitrogen oxide (NOx) emissions by up to 80% and fuel burn by up to 35%.

Thermal efficiency is higher than that of fuel cells

“This is an excellent chance to begin developing the critical technologies that will enable the industry’s first hydrogen vapor injection engine to move from concept to reality,” said Geoff Hunt, vice president and director of engineering and technology at Pratt & Whitney. The HySIITE engine will burn hydrogen in a thermodynamic engine cycle with a steam injection to cut NOx, -nitrogen oxides, and greenhouse gas emissions dramatically. When compared to the usage of “drop-in” sustainable aviation fuels, the semi-closed design envisioned for HySIITE will achieve greater thermal efficiency than fuel cells and lower total operating costs.