Aviation accounts for approximately 2-3% of global CO₂ emissions. In Denmark alone, flights to and from Denmark emit around 3 million tons of CO₂ annually. But CO₂ is only part of the story.
Up to two-thirds of aviation’s climate impact comes from non-CO₂ effects, primarily caused by contrails – the white streaks often seen in the sky after aircraft pass. These contrails form when water vapor freezes onto tiny particles from jet exhaust, creating ice crystals that trap heat in the atmosphere, especially during nighttime flights.
One promising solution is low aromatic jet fuel. This fuel significantly reduces the formation of contrails and ensures cleaner combustion, which in turn improves air quality around airports.
Non- CO₂-effects refer to the climate impacts that do not originate from CO₂ emissions during combustion. They typically occur with the formation of contrails.
Contrails consist of ice crystals that form when water vapor freezes onto small particles from the aircraft’s exhaust.
How do they affect the climate?
- During the day, they trap Earth’s heat but also reflect sunlight back into space, creating both a warming and cooling effect.
- At night, there is no sunlight to reflect, so the contrails act solely as an insulating layer.
Where is the non-CO₂ effect the worst?
On night routes, such as between Europe and North America, where weather conditions make it easier for contrails to form and linger longer.
Low aromatic jet fuel
One of the crucial tools for reducing harmful climate effects from aviation is Sustainable Aviation Fuel (SAF). However, SAF currently accounts for only 0.05 percent of consumption, and there is no immediate prospect of a significant increase. The ambition is clear, but the implementation is slow.
Therefore, Kalundborg Refinery points to a realistic solution that can be implemented immediately: Low aromatic jet fuel.
By adding a bit more hydrogen to conventional jet fuel (Jet A1), the aromatic content is significantly reduced. This decreases the formation of contrails and ultrafine particles, thereby reducing both environmental and climate impacts. Research indicates that halving the aromatic content can reduce non-CO₂ effects by up to 20 percent.
Large-scale production of low aromatic jet fuel
Low aromatic jet fuel is an alternative to traditional jet fuel with a lower aromatic content.
The aromatic content is reduced by adding a small amount of hydrogen to traditional jet fuel (Jet A1).
Research indicates that halving the aromatic content can reduce non-CO₂ effects by up to 20 percent.
Additionally, a lower aromatic content results in cleaner combustion and thus the emission of fewer ultrafine particles. This will have a particularly positive effect on air quality around airports.
Kalundborg Refinery collaborates with Airbus
One of the world’s largest aircraft manufacturers, Airbus, has for years been seeking solutions to reduce the climate impact of aviation – not only in the long term but also immediately. With a new collaboration with Denmark’s largest refinery, Kalundborg Refinery, an important step is being taken from potential to practice.
The new collaboration on the development of low aromatic jet fuel not only marks the beginning of a test. It marks the beginning of a new narrative about green aviation with Denmark as the sender and Kalundborg as the driving force.
When Airbus receives Danish-produced low aromatic jet fuel for testing, it is a concrete example of how Danish industry can deliver tangible and realistic solutions for the green transition of a high-emission sector like aviation.
We are proud of our cooperation with Airbus. It underlines the product’s potential and the great interest from the industry. This fuel can already be produced on an industrial scale, reducing aviation’s global climate and environmental footprint. Therefore, we would like to invite the industry and the authorities to engage in dialogue on how the fuel can be implemented.
Claus Navntoft
Managing Director
We are proud of our cooperation with Airbus. It underlines the product’s potential and the great interest from the industry. This fuel can already be produced on an industrial scale, reducing aviation’s global climate and environmental footprint. Therefore, we would like to invite the industry and the authorities to engage in dialogue on how the fuel can be implemented.
Claus Navntoft
Managing Director
