Fueling greener aviation with hydrogen
PressPacs November 1, 2024

FOR IMMEDIATE RELEASE

“Challenges of Decarbonizing Aviation via Hydrogen Propulsion: Technology Performance Targets and Energy System Trade-Offs”
ACS Sustainable Chemistry & Engineering

Despite ongoing efforts to curb CO₂ emissions with electric and hybrid vehicles, other forms of transportation remain significant contributors of greenhouse gases. To address this issue, old technologies are being revamped to make them greener, such as the reintroduction of sailing vessels in shipping and new uses for hydrogen in aviation. Now, researchers reporting in ACS Sustainable Chemistry & Engineering have used computer modeling to study the feasibility and challenges of hydrogen-powered aviation.

“While there is a long way to go for hydrogen aviation to be realized at scale, we hope that our analysis of both onboard system design and enabling infrastructure will be used to prioritize development efforts,” says Dharik Mallapragada, one of the study’s coauthors.

The aviation industry’s energy-related CO₂ emissions have grown faster than those of rail, road and shipping in recent decades, according to the International Energy Agency. To reduce the potential climate impacts of this growth, scientists are improving aircraft design and operation, and developing low-emission fuels such as hydrogen, which is used for direct combustion or to power electric fuel cells. Hydrogen’s appeal as a fuel source is that its use produces no CO₂ and provides more energy per pound than jet fuel. To understand the potential impact of switching from traditional jet fuel to hydrogen fuel in aviation, Anna Cybulsky, Mallapragada and colleagues modeled its use in the electrification of regional and short-range turboprop aircraft.

The researchers calculated that the extra bulk of a hydrogen fuel tank and fuel cells retrofitted to an existing plane would need to be offset by weight reductions elsewhere, such as reducing the aircraft’s payload (cargo or passengers). This could mean that more flights would be needed to deliver the same payload. The team’s model suggested, however, that improvements in fuel cell power and the fuel system’s gravimetric index (the weight of the fuel in relation to the weight of the full fuel tank) could eliminate the need to reduce payload, thus eliminating the environmental impact of additional flights. At the same time, they noted that shifting to hydrogen-powered flight may reduce the aviation industry’s CO₂ emissions by up to 90%.

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