E-fuels in Aviation: Less CO2 Emissions Thanks to Synthetic Kerosene?

Ten percent of German fuel consumption should be covered by renewable, alternative aviation fuels by 2025. That’s the ambitious goal of the “Aviation Initiative for Renewable Energy in Germany” (Aireg) that wants to propel the production and use of such e-fuels in aviation. While it’s possible for other alternative drive systems, such as electric, solar and hydrogen engines, to be used in road transport or shipping, it’s unlikely that they would be used in aviation.

Important sectors of the economy will also require liquid fuels in the future: According to a recent study by Prognos “Status und Perspektive flüssiger Energieträger in der Energiewende” (Status and prospects of liquid fuels in the energy transition), such motor fuels and heating fuels currently account for around 98 percent of the operating energy in the German transport sector. As a result, liquid fuels and raw materials are either hard or impossible to replace, especially in the air traffic and chemical industry. “If Germany wants to reach the climate policy target of reducing greenhouse gases by 80 to 95 percent, it is crucial to increasingly produce liquid fuels such as kerosene, gasoline or diesel with reduced greenhouse gas emissions,” says Jens Hobohm, Head of Energy Management and Director of Studies at Prognos AG.

Pipelines supply kerosene to airports such as the Frankfurt Airport. The fuel is delivered from the tank storage facility on the airport grounds to the respective aircraft parking positions using an extensive underground pipeline system.

Furthermore, a study by the German Energy Agency (dena) conducted on behalf of the German Association of the Automotive Industry (VDA) recently revealed that e-fuels produced from renewable resources are needed to meet the EU’s climate protection targets in the transport sector: Even in a scenario with a lot of traffic electrically powered by batteries, e-fuels will account for more than 70 percent of the final energy demand for all modes of transport in the EU by 2050. Hobohm forecasts that “Germany’s international air traffic and shipping traffic alone will require around 550 petajoules of energy by 2050”. By the way, 3.6 petajoules is equal to one terawatt hour (TWh) or one billion kilowatt hours (kWh).

Climate-friendly E-fuels: Production Process and Areas of Application

E-fuels are virtually carbon-neutral, synthetic motor fuels and heating fuels that can be produced from renewable electrical energy: Renewable electricity is converted into liquid fuel by using carbon and hydrogen produced via electrolysis in what is known as the power-to-liquid process (PtL). When carbon is taken from the atmosphere or biomass, however, this procedure is called the power-and-biomass-to-liquid (PBtL) process.

According to the Prognos study, e-fuels can be processed, stored, transported and used in exactly the same way as current liquid fuels. Existing infrastructures such as pipelines or gas stations could be used as well as existing vehicle fleets. In addition, it is only possible to significantly reduce greenhouse gases by 95 percent using e-fuels. There would also be favorable effects on climate protection and trade on an international scale. “PtL production would take place mainly in very sunny and windy countries and open up positive economic perspectives in those places,” said Hobohm. The imports would also offset Germany’s trade balance. The current view estimates that PtL could be produced in 2050 at a cost between 0.70 and 1.30 euros per liter, assuming a large-scale industrial entry into PtL technology.

Lufthansa now wants to get out of the climate protection initiative Aireg: As the magazine Airliners reported on June 15, 2018, the Group terminated its membership at the end of the year. Nevertheless, the airline’s interest in alternative fuels remains high, according to a spokeswoman. According to Lufthansa itself, it was the first airline in the world to test bio-kerosene in regular flight operations in 2011. The final report of the “BurnFAIR project” states that the bio-kerosene performed very well overall during the 1188 trial flights. Further need for action, however, is still required in many places before bio-kerosene can become economically competitive and produced in an environmentally sustainable manner.

CO2-neutral Expansion of International Air Traffic from 2020 Onwards

At the International Civil Aviation Organization’s (ICAO) 39th triennial session held in Montreal in autumn 2016, the 191 ICAO member states agreed upon an instrument for the global protection of the climate for international air traffic. ICAO’s adoption of Resolution A39-3 will see the international introduction of the global market-based climate protection instrument through the offsetting system CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation) starting in 2020. The international aviation industry is, therefore, the world’s first industry with a global climate protection instrument in place. CORSIA is designed to enable the carbon-neutral expansion of international air traffic from 2020 onwards. From 2020, growth-related CO2 emissions in air traffic between the participating countries will be offset by specially implemented climate protection projects supervised by the UN.

(Source: BDL)

Text by Benjamin Klare
Photos: Fraport
Graphic: IWO