The Academy of Technologies unveils its report “Decarbonizing the aviation sector with sustainable fuel”. She defends a decarbonization project that relies on airport infrastructure and current fleets through the development of a new sector of “sustainable aviation fuel”.
Should international aviation be regulated? Ban domestic flights? Be ashamed to fly? Or on the contrary bet on the hydrogen plane and other decarbonation technologies? The questions surrounding air transport are multiplying. For its part, the Academy of Technologies wants to believe in the decarbonization of aviation thanks to the “sustainable aviation fuel”compatible with existing infrastructure and aircraft.
“Sustainable fuels could reduce the emissions of a flight by 10”, shares Daniel Iracane, expert from the energy center of the Academy of Technologies, pilot of the report The decarbonization of the aviation sector by the production of sustainable fuels. A Paris-New York round trip powered by synthetic kerosene would thus emit around 100 kg of CO2 against more than a ton today. Enough to make aviation compatible with respecting a carbon budget of 2 tonnes per French person in 2050.
To manufacture “sustainable kerosene” on a large scale in large industrial installations, the Academy identifies “three key ingredients”to know “the carbon, hydrogen and energy to produce them”. For this production, it will be necessary to mobilize the biomass of animal and vegetable origin which provides all of these three ingredients: used cooking oil, animal fat and forestry and agricultural residues. The potential of this biomass remains limited and subject to many uncertainties. It will therefore also be necessary to produce hydrogen by electrolysis of water, and combine it with CO2 captured in industrial waste or extracted from the air. This option will require a lot of electricity.
Decarbonized electricity to decarbonize aviation
Today, France uses less than 0.1 million tons of synthetic kerosene each year. It produced 532 terawatt hours (TWh) of electricity in 2021. “Considering that 10% of the biomass intended for energy can be devoted to the aviation sector, it would take 20 TWh of electricity to produce 2 million tonnes of sustainable kerosene in 2035 and 170 TWh in 2050 for 6 million tonnes of sustainable kerosene”, calculates Daniel Iracane. The majority of the fuel would then be obtained by electrolysis of water and capture of CO2.
If traffic were to decrease by a few tens of percent, that would not change the scale of the challenge. “We are not very dependent on traffic assumptions”, assures Daniel Iracane. The Academy denies not having explored the path of a much stricter framework for future air transport, because it does not seem to be emerging at European and global level.
The Academy therefore identifies two major challenges: easier access to biomass and carbon-free electricity, as well as significant industrialization from 2030. “Thanks to its already carbon-free electricity, France has the means to initiate a sustainable kerosene industrial sector from 2030, where the majority of European countries will first have to decarbonize their electricity mix or depend completely on massive imports of sustainable fuel. »defends the academician who has spent a large part of his career in nuclear energy.
Whatever the technological innovations, it will be necessary to multiply the electricity production capacities. Electricity will be needed in particular to fly planes, to move ships and to produce nitrogen fertilizers, warns the Academy of Technologies. “Ultimately, a doubling of electricity production will be necessary in 2050 to decarbonize the various sectors of the economy”, shares Daniel Iracane. The air sector would mobilize 10 to 15% of this new electricity production from renewable energies and new nuclear reactors.
At technological maturity, the Academy of Technologies estimates the cost of producing synthetic kerosene at €2.5 per litre, more than double the cost of extracting current fossil kerosene. This corresponds to a carbon abatement cost of around €300 per ton of CO2.