Pratt & Whitney was selected by the US Department of Energy (DoE) to develop novel, high-efficiency hydrogen-fueled propulsion technology for commercial aviation, as part of DoE’s Advanced Research Projects Agency-Energy (ARPA-E) OPEN 2021 program (earlier post).
The Hydrogen Steam-Injected, Inter‐Cooled Turbine Engine (HySIITE) project will use liquid hydrogen (LH2) combustion and water vapor recovery to achieve zero in-flight CO2 emissions, while reducing nitrogen-oxide (NOx) emissions by up to 80% and reducing fuel consumption by up to 35% for next-generation single-aisle aircraft.
The HySIITE engine will burn hydrogen in a thermodynamic engine cycle that incorporates steam injection to reduce NOx emissions. The semi-closed system architecture planned for HySIITE will achieve thermal efficiency greater than fuel cells and reduce total operating costs when compared to using “drop in” sustainable aviation fuels.
This truly is an exciting opportunity to start developing the key technologies that could bring the industry’s first hydrogen steam injected, inter-cooled engine from concept to reality. For nearly 100 years, Pratt & Whitney has been at the forefront of innovating cutting-edge technologies to continually advance the efficiency of aircraft engines, and we are thrilled to be selected to work on what could be the next breakthrough technology for aviation.
This is the first direct collaboration between Pratt & Whitney and ARPA-E.
Separately, Airbus announced a collaboration with CFM to develop a direct combustion aviation engine also fueled by liquid hydrogen. (Earlier post.)
Interest in using liquid hydrogen as an alternative to conventional hydrocarbon aviation fuels reaches back at least to the 1950s, when the impetus was primarily improving military aircraft performance. In the 1970s, the interest switched to concern over fossil fuel depletion (as perceived at the time), the oil crises, and air pollution. Now the concern is greenhouse gases and climate change.