A comparative life cycle assessment of clean aviation fuels

In this study, life cycle assessments and comparative evaluations are performed for different types of renewable and alternative fuels for aircrafts. The life cycle impacts of both hydrogen and ammonia fuels are primarily investigated considering conventional and renewable energy-based routes. The overall life cycle impacts of several hydrocarbon fuels including kerosene, ethanol, methanol, dimethyl ether, and biodiesel are also studied. The steam methane reforming-based route for hydrogen and ammonia fuels is found to have higher global warming potentials as compared to alternative production routes. High phosphate emissions result in a higher freshwater eutrophication potential for the solar-based route for ammonia fuel. Fossil fuel-based dimethyl ether is found to have a comparatively higher global warming potential of 1.3 kgCO(2) equivalent per tonne-km amongst the considered hydrocarbon fuels that include ethanol (1.1 kgCO(2) equivalent per tonne-km), kerosene (1.04 kgCO(2) equivalent per tonne-km), methanol (1.01 kgCO(2) equivalent per tonne-km), and biodiesel (1.07 kgCO(2) equivalent per tonne-km). Dimethyl ether is found to entail high toxicity potentials and the reduction of life cycle arsenic, barium, cadmium, chromium, cobalt, and lead emissions is recommended. However, higher photochemical ozone formation potentials of 0.0055 and 0.0046 kgNOx equivalent per tonne-km are associated with biodiesel and kerosene fuels respectively. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study conducted life cycle assessments and comparative evaluations for various renewable and alternative fuels for aircraft, revealing differences in global warming potentials, toxicity potentials, and photochemical ozone formation potentials among different fuels.