Session: 03-06 Liquid fuels

Paper Number: 84359

84359 - Ammonia as an Aircraft Fuel: Thermal Assessment From Airport to Wake 

Over the past two decades, zero-emission aviation has focused on using drop-in biofuels to replace fossil-based jet fuels. Drop-in biofuels or sustainable aviation fuels (SAF) are an attractive near-term option to reduce carbon emissions since they can be incorporated into the global fleet with no aircraft hardware or major infrastructure changes required. While significant advances have been made in the chemistry and production of such fuels, scaling up manufacturing capability to provide cost-competitive drop-in jet fuels for the global fleet and completely eliminating emissions have been a challenge.

Hydrogen is recently being touted as an alternative with no carbon-dioxide emission. However, use of hydrogen as an aviation fuel faces significant technical challenges because of storage requirements, combustion characteristics, and potential for increased emissions of nitrogen oxides.

Any new technology for aviation needs to address several concerns concurrently: (1) technical requirements for commercial aviation, (2) over-whelming concern for safety, (3) extent and cost for upgrading the global fleet of airplanes and airports, and (4) global supply chain. Accordingly, suitable substitute fuels for aviation have the be benchmarked and compared over the entire value-chain from the airport to the wake of the engine.

This paper discusses ammonia as a carrier of electricity-derived, green, hydrogen for aviation, with near-zero emission. Ammonia is proposed here not only as a carrier of hydrogen as fuel, but also for providing cooling for compressor intercooling and cooled cooling air, for NOx elimination, and for condensation of water vapor in the exhaust for reduction of contrail formation. The performance of ammonia with regards to all of these objectives will be evaluated. A detailed analysis of the energetics concerning the flow of ammonia from leaving the airport storage, to the fuel tanks of the aircraft to the wake of the engine will be performed. Conclusions will be drawn on how ammonia compares to Jet A, SAF, and hydrogen in overall performance as an aviation fuel.

Presenting Author: Marcel Otto University of Central Florida

Presenting Author Biography: PostDoc<br/>PhD, University of Central Florida, Mechanical Engineering, 2019<br/>MS, University of Central Florida, Mechanical Engineering, 2015<br/>MS, TU Berlin Mechanical Engineering, 2013<br/>BS, TU Berlin Mechanical Engineering, 2010

Authors:

Marcel Otto University of Central Florida
Ladislav Vesely University of Central Florida - CATER
Jayanta Kapat University of Central Florida
Michael Stoia Boeing Research and Technology
Nicholas Applegate Boeing Research and Technology
Greg Natsui GE Research