As noted in the ARPA-E REEACH project description summaries, the team proposes to develop “a highly efficient and cost-effective hybrid-electric turbogenerator suitable for powering narrow body aircraft like the B737.” This project supports the overall objective of the REEACH program to develop a disruptive system to convert chemical energy stored in energy-dense carbon neutral liquid fuels (CNLFs) into electric power for aircraft propulsion via electric powertrains and other key systems.
Schematic illustrating the project’s conceptual design for integrating a high-power density solid oxide fuel cell (SOFC) into the flow path of an aircraft engine. Design features include a unique approach to recycling some of the anode exhaust to react the fuel in an autothermal reformer (ATR) and a unique SOFC stack design to improve thermomechanical robustness and redox stability during transient operation. The SOFC produces efficient DC electrical power for aircraft electrical loads and as needed, battery energy storage.
In 2017, air travel accounted for about 2.6% of greenhouse gas emissions in the U.S., and half of that was attributed to narrow-body aircraft such as the Boeing 737. Using decarbonized electrified propulsion for narrow-body aircraft can make an impact on overall emissions. Furthermore, the efficiency gains expected by the energy storage and power generation sub-systems developed in this program could reduce aircraft fuel consumption.
Mines’ role in the program includes system-level modeling, novel fuel cell and fuel processor design and integration, and development and implementation of advanced controls to ensure reliable operation of the fuel cell housed inside the turbogenerator flow path. The Mines effort will fund two graduate students and partially support a research faculty member.
This work is closely tied to Professor Braun’s research funded through the ARPA-E INTEGRATE program. Professor Jackson points out that while there is a similar systems-level integration for high efficiency with the INTEGRATE program, the REEACH program has the added challenge of the high-velocity, high-altitude applications of flight.
“Rather than integrating with an IC engine, this program is placing the electric production of the fuel cell inside the flow path of a gas turbine,” Jackson says. “This has been tried before, but we are taking a novel approach that may enable the fuel cell to survive in this dynamic environment where conventional fuel cell architectures would almost surely fail.”
Work on the REEACH program is expected to begin this fall.