Researchers are developing a new process that could see sustainable aviation fuel implemented across the world.
Following a joint initiative, the collaboration between the Paul Scherrer Institute PSI and the Swiss start-up, Metafuels, is now ready for first-stage construction and operation. The first pilot plant, located on the PSI campus, will validate the technology and prepare it for large-scale commercial deployment in the near future.
PSI and Metafuels are working to develop and market an efficient process for the production of affordable synthetic kerosene from renewable resources. The plan is to produce high-quality, sustainable aviation fuel using water, renewable electricity, and sustainably sourced carbon dioxide.
This sustainable alternative is compatible with existing jet engines as a blend of traditional fossil-based kerosene or, eventually, as a primary fuel. Working with the Metafuels team, the researchers have developed a catalytic process that not only avoids the use of fossil feedstocks but also offers superior selectivity.
The process enables renewable energy to be used more efficiently than in alternative SAF processes. PSI and Metafuels scientists want to use the new sustainable aviation fuel (AerobrewTM) to close the carbon cycle and achieve net zero in air transport.
How does traditional aviation fuel impact the planet?
When aviation fuel is burned by an aircraft, it releases not only carbon dioxide (CO2) but also creates other byproducts, including nitrogen oxides (NOx), water vapour, soot, and aerosols which react with the atmosphere and contribute substantially to global warming.
The formation of condensation trails is just as important. As they burn fossil kerosene, jet engines also emit soot particles and other condensation nuclei. These instantly form ice crystals that appear as condensation trails in the sky at cold temperatures and high altitudes. Under certain conditions, this can lead to the formation of artificial clouds, known as aircraft-produced contrail cirrus clouds. Although some of these clouds allow visible sunlight to pass through almost unimpaired, they reflect and absorb the infrared rays from the Earth’s surface very efficiently, preventing the radiation from escaping into outer space.
“The molecular composition of synthetic fuels makes it possible to manipulate the combustion process and significantly reduce the formation of soot particles, for example,” explained Marco Ranocchiari. The latest research results indicate that this not only helps reduce the planet’s net warming but also improves local air quality at airports.
A report published by the European Commission, ‘Updated analysis of the non-CO2 effects of aviation,’ confirms that non-CO2 effects make up two-thirds of aviation’s climate impact.
In order to save the planet, it is clear that governments must work with businesses and look at adopting more sustainable options for air travel.
A fresh challenge
For more than a decade, the co-founders of Metafuels have been working on developing strategies and technologies to support the transition from fossil fuels to renewable energy sources. They have worked previously on complex challenges associated with the decarbonisation of energy systems. The development of sustainable aviation fuel now offers them a fresh challenge.
“First of all, we obviously had to carry out many relevant experiments in the laboratory,” said Marco Ranocchiari, Head of the Energy System Integration (ESI) experimental platform at PSI. “It worked, and we could confirm our scientific concept. We were able to use a catalytic reaction to develop a process for producing synthetic kerosene from green methanol and, at the same time, achieve significantly better selectivity than with the alternative SAF technologies.”
The new pilot plant will consist of two container modules that will be integrated into the existing infrastructure. The researchers want to validate the technology so sustainable aviation fuel can be prepared for large-scale use.
PSI, in partnership with industry and other research partners, uses the ESI platform to develop and demonstrate processes that promote a carbon-neutral energy system. The focus here is on energy conversion processes that convert renewable energy and feedstocks into a usable energy source for a wide range of applications, including sustainable aviation fuel.
