Liquid Hydrogen: A Mirage or Potent Solution for Aviation's Climate Woes?
T Reed Miller1,2, Marian Chertow2, Edgar Hertwich3
1Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States.
Environmental Science & Technology
|June 23, 2023
Summary
Liquid hydrogen (LH2) shows potential for reducing aviation
Area of Science:
- Environmental Science
- Climate Change Research
- Sustainable Aviation Fuels
Background:
- Aviation industry faces significant climate impact challenges.
- Growth in air travel necessitates sustainable fuel alternatives.
- Liquid hydrogen (LH2) is a potential carbon-neutral jet fuel candidate.
Purpose of the Study:
- To conduct a well-to-wake life cycle assessment of LH2.
- To compare climate impacts of various hydrogen production routes against conventional jet fuel and biofuels.
- To evaluate environmental and health impacts per passenger-distance for different aviation fuel scenarios.
Main Methods:
- Life cycle assessment (LCA) methodology.
- Analysis of 17 hydrogen production routes and conventional fuels.
- Modeling climate impacts (CO2 and non-CO2) for a Boeing 787-800 aircraft across various flight distances.
Main Results:
- Contrail cirrus impacts are significantly higher for LH2 (81%) than conventional fuel (32%).
- Dominant commercial LH2 pathways show 8-121% greater life cycle impacts than conventional jet fuel.
- Novel LH2 routes offer potential reductions up to -205%, while renewable LH2 shows a best-case reduction of -67%.
Conclusions:
- LH2 combustion climate impacts, particularly from contrail cirrus, require further research.
- While some LH2 pathways show promise, current commercial routes exceed conventional fuel impacts.
- Renewable energy-derived LH2 is not climate neutral but offers significant life cycle reductions compared to conventional jet fuel.
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