Aviation

Decarbonizing Aviation: Time for Hydrogen to Take Off

Without some course correction on how we fly today, CO2 emissions from commercial aircraft could triple by 20501. Currently accounting for around 2.8% of global CO2 emissions2, aviation remains one of the harder to abate sectors of transport with no practical alternative mode available for cross global travel.

Aviation Is Flying Toward a Cleaner Future Thanks to Hydrogen

Exhaust emissions while airborne however, is only one side of the story: emissions from the entire airport infrastructure in constant operation mode is the other. Changing how we personally fly - or rather when we choose to fly - is our individual challenge. But changing how planes fly and how the aviation infrastructure operates so as to be less carbon intensive, is a challenge the industry must take on. And it has. Collectively, airlines are targeting net-zero carbon emissions by 20503. Hopes of hitting that target could well hinge on hydrogen with its high decarbonizing potential both in the air and on the ground. With its history and scope of expertise , Linde is fully onboard to help.

In the Air: Sustainable Aviation Fuels (SAF)

A promising pathway to decarbonizing aviation is to fuel today’s planes with synthetically produced, cleaner alternatives to kerosene - which is refined from fossil fuel feedstock such as crude oil. One production method of a more sustainable aviation fuel (SAF) employs a Power to Liquid (PTL) process, which relies on the supply of a sustainable carbon feedstock (biomass or other unavoidable industrial carbon dioxide sources) and the production of green hydrogen through electrolysis using renewable energy. The carbon and hydrogen are converted to synthesis gas, a mixture of carbon monoxide and hydrogen, which in turn is converted to longer chain hydrocarbons for the production of jet fuel or SAF via the Fischer-Tropsch Process.

Portrait of Kate Macfarlane

An Expert Perspective

"We can stay at home, or we can find a more sustainable solution" says clean hydrogen expert, Kate Macfarlane.

The majority of SAF fueling today's planes comes from cooking oils and animal fats, or biomass, such as sugarcane and corn grain. However, such feedstocks are grown on arable land, which could potentially be used to grow food, so feedstock limitation becomes a challenge. And this is where the production of PtX Kerosene via renewable hydrogen can help in finding a solution for more sustainable flights.

In the air: The pursuit of Zero-Emission Flight

The promise of hydrogen’s zero-carbon emissions is also propelling the development of cleaner alternative propulsion technologies for future aircraft. Most of today’s hydrogen-powered flight concepts use fuel-cells to generate electricity or combust hydrogen in an engine - or both. But while theoretically tried and tested, hydrogen combustion in practice remains a challenge.

Safe and secure hydrogen storage on planes could inspire a complete rethink of aircraft design. Airbus is taking the lead in the development of hydrogen flight with ZEROe.

On the ground: Hydrogen Hub Airports

Efforts to decarbonize the aviation industry are not limited to reducing emissions from flights. Planes take off and land from the complex supportive ecosystems we know as airports. The facilities themselves need heating and lighting, passenger buses and other airport vehicles need fueled , and energy is needed for all of this. These hubs of activity could become hydrogen hubs - offering a way to achieve climate-neutral operations across the entire value chain.

Linde is using its expertise to study the potential for such a hydrogen hub in the city state of Singapore. The two-year study in cooperation with Airbus, Changi Airport Group, and the Civil Aviation Authority of Singapore will examine the infrastructure requirements and supply solutions to support hydrogen-powered aircraft and airport operations at Singapore’s Changi Airport. These requirements include the production, storage and distribution of hydrogen in aircraft ground services, operational equipment and refueling systems.

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