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Future planes will fly on CO2 and hydrogen

Researchers have received DKK 37 million from the EU to produce sustainable aviation fuels from CO2 and hydrogen. The project is groundbreaking because the aircraft does not need to have new engines in order to fly sustainably.

By Birgitte Dalgaard, , 3/22/2021

While air travel today is the mode of transport that emits the most CO 2 to the detriment of the climate, CO2 is exactly the important part of the sustainable aviation fuels that the aircraft will be fueled by in the future.

– We have received just over DKK 37 million to develop half a litre of sustainable aviation fuel, says Professor Morten Birkved from the Department of Green Technology.

Together with some of the key players on the European stage within research and development of sustainable energy, Morten Birkved is part of the Take-Off project, which will develop green aviation fuels.

We have received just over DKK 37 million to develop half a litre of sustainable aviation fuel

Morten Birkved, Professor

Unlike other projects that are also working on making flights green, the Take-Off project stands out by the fact that the aircraft do not have to replace its engines to fly green.

– People imagine that the planes must have solar panels on their backs in order to be climate-neutral. But no, it is the same Boeing 737 that flies us to Paris today that we will use in the future.

– It is the exact same engine and it is only the fuel that we will change from fossil jet fuel to sustainable jet fuel, points out Professor Morten Birkved.

Most sustainable method

Before the corona pandemic paralysed the pulsating air traffic, the European Environment Agency released the report “European Aviation Environmental Report 2019”, which forecasts that from 2017-2040, the European aviation sector will grow by 42 per cent, while CO2 emissions will increase 21 per cent to 198 megatons or 198,000,000 tons of CO2.

Therefore, researchers all over the world are working hard to develop sustainable aviation fuels as quickly as possible so that passengers can enjoy the fast ride around the world without a guilty conscience.

The researchers are investigating various methods for creating sustainable aviation fuel concepts, mainly based on biofuels and the technology Fischer-Tropsch process, which was also used during World War II.

Hydrogen and CO2

– We will never move people without emitting CO2, but we all want to get as much fuel as possible for the least possible climate impact. We do not yet know which method is most environmentally and economically sustainable, so we have to try our way, says Morten Birkved:

In the Take-Off project, the researchers will create sustainable aviation fuel from hydrogen and CO2. The CO2 must be harvested from the chimney of, for example, waste incinerators, while the hydrogen must be produced via electrolysis using wind turbine energy. A new type of catalyst, which the research institute TNO in the Netherlands have a patent on, must efficiently convert CO2 and hydrogen into fuels.

– If this method is successful in producing aviation fuels, I estimate that it may well prove to be both the most sustainable and also the cheapest method because it does not require new airplanes or engines. It just requires that we get the special catalysts up and running, Morten Birkved explains.

How much does it cost

The researchers at SDU are responsible for preparing the calculations that will ultimately show how sustainable the method in question actually is compared to other methods.

It is an extremely complicated calculation, which includes using the climate impact from concrete, composite and metals from which the wind turbines are built so that the fuel ends up as gas from the aircraft's engines.


  • Grant: 5 million Euros from Horizon 2020, the EU's largest research and innovation program.
  • Project period: Four years.
  • Partners in the project: TNO, The French National Center for Scientific Research (CNRS), RWE, which is the largest energy producer in Germany, Mitsubishi Hitachi Power Systems Europe GmbH (MHPSE), Asahi Kasei Europe GmbH (AKEU), FEV, SkyNRG, which is the market leader in sustainable aviation fuels, RWTH Aachen University, University of Southern Denmark, CO2 Value Europe.

– We have to produce half a litre of jet fuel, but we will have to scale up and calculate how sustainable the method is when the system has to produce one million litres of jet fuel a week. For that calculation, we have a software system, Aspen, which we are really good at operating.

– But we must also examine the environmental footprint of aviation fuel. If, for example, toxic substances are created in the exhaust, we are of course forced to include the effects of these in our calculations, says Morten Birkved.

In addition to being responsible for the calculations of the environmental impact of aviation fuels, the researchers from SDU must also calculate how much more expensive the ticket prices will end up being for consumers.

– I do not yet want to give an estimate of how much more expensive tickets will be. Things take time. If the outcome is positive, then we may be ready to refuel the first aircraft by 2030.

– But there is no doubt that both airlines and customers agree that it will be more expensive to fly sustainably. We can already see how many air passengers compensate for the climate by purchasing, for example, tree planting, Morten Birkved points out.

Meet the researcher

Morten Birkved is professor and head of SDU Life Cycle Engineering at Department of Green Technology.


Editing was completed: 22.03.2021