This is how scientists plan to produce sustainable aviation fuel

It is only a matter of years before we can produce sustainable aviation fuel in Denmark. That is the conclusion to a new report by researchers from the University of Southern Denmark. The researchers estimate that the production facilities for 100 % green aviation fuel could be ready as early as 2025.

By Birgitte Dalgaard, , 11/5/2019

In cooperation with Nisa, Nordic Initiative for Sustainable Aviation, and consulting engineering company Niras, researchers from the University of Southern Denmark have launched a report with the conclusion that sustainable aviation fuel made from biogas, CO2 and hydrogen can be produced in Denmark and the Nordic countries in just a few years.

The study shows that we have the necessary technologies to convert methane to sustainable fuels for aircraft and other heavy vehicles, and the researchers estimate that the first production facility for 100 % green aviation fuel could be ready in 2025.

- It looks like the price of the green fuel will be two to three times higher than that of fossil fuels. But as fuel cost only makes up 25-30 % of the ticket price, the ticket will not be two to three times more expensive, PhD student and lead author of the report, Anders Winther Mortensen of SDU Life Cycle Engineering, explains.

Utilizing our CO2

The type of facility that the researchers want to produce sustainable aviation fuel already exists in several other countries. Qatar, Nigeria, Malaysia and South Africa already have the facilities, and another one is underway in Uzbekistan.

These existing facilities convert natural gas to liquid fuels, but the Danish facility will be different in that the gas comes from manure and waste food, i.e. the gas from biogas facilities.

Biogas consists of methane and CO2: The pure methane is sent into the natural gas distribution network while the CO2 goes up the chimney as a waste product.

- We want to utilize this CO2. Methane from degassed manure and straw is not enough to meet our fuel demands. But the CO2 from biogas can help us. We can convert CO2 to methane by adding hydrogen from wind and solar power, Anders Winther Mortensen says.

- And if that is still not enough, we can harvest CO2 from other places like waste incinerators or directly from the atmosphere. If we harvest CO2 from the atmosphere, we have an inexhaustible source, because the fuels re-emit the CO2 when they are burned.

Fuel for all forms of heavy transportation

When the researchers have enough methane to cover the need for sustainable fuels, the methane gas can be converted into liquid fuel using a chemical process known as Fischer-Tropsch. The liquid fuel can then be poured directly into the aircraft’s tank.

The Fischer-Tropsch process is an old technology that was invented in 1923 by the two German chemists Franz Fischer and Hans Tropsch. The technique has been used by countries that were subject to oil embargoes, e.g. Germany during the Second World War and South Africa during Apartheid.

- A lot of fossil fuels are already made using this process, but the chemistry and the technology are the same for the sustainable fuels. And it is not only aviation fuel that we get from the process. We also get diesel, gasoline and naphtha, which we can use to produce plastic, Anders Winther Mortensen explains.

- Gasoline and diesel can be used as fuel for heavy transportation such as trucks and ships. That way we can fuel all the heavy transportation.

Need for political investment

All numbers point to the need for an alternative to oil-based jet fuel. A trip to Thailand emits around 3 tons of CO2 pr. person according to But the UN has found that every person in the world cannot emit more than 2-3 tons pr. year if we are to slow down global warming.

And the airline industry is very interested in the project, but the sustainable fuels will not find their way to the fuel tanks without political regulation or support, e.g. making the production of hydrogen cheaper.

- It is inevitable that sustainable airline tickets will be more expensive, but we can help the technology along with political measures. And the extra cost is not huge. We are talking $20 a month pr. person for an energy system without fossil fuels, Anders Winther Mortensen says.


Read the report: A pre-feasibility study on sustainable aviation fuel from biogas, hydrogen and CO2 

Supported by: Copenhagen Airports, SAS, ARC Amager Ressourcecenter, Nordic Energy Research, Dansk Luftfart, Nature Energy, Danish Energy

Meet the researcher

Anders Winther Mortensen is a PhD Student at SDU Life Cycle Engineering and first author on the report: A pre-feasibility study on sustainable aviation fuel from biogas, hydrogen and CO2.

Anders Winther Mortensen