Energy: ENEA starts research line on green aviation fuels

ENEA has started a research line on so-called “e-fuels”, green aviation fuels based on renewable hydrogen and carbon dioxide, which envisages the design of a pilot plant to be built in collaboration with the Polytechnic of Milan. The iniative is part of the Operational Research Plan (POR) on renewable hydrogen coordinated by ENEA to address various technological challenges, including production and storage of green hydrogen for distribution and end uses. The POR is funded by the Ministry of the Environment and Energy Security with 110 million euros from PNRR funds.

 “E-fuels show particular promise for those sectors hard to electrify like the aviation sector. The technologies involved in the production processes of new synthetic fuels are not developed enough; in this context, we started an activity on e-fuels, particularly on e-kerosene", explained Giulia Monteleone, head of the ENEA Energy Production, Storage and Use Division and contact person for the POR.

According to the new EU environmental targets (Fit for 55 and REPowerEU), the objectives of the aviation sector include the use of at least 2% of green fuels by 2025, up to 85% by 2050. In the mix of technological solutions for the decarbonisation of the sector, e-kerosene stands out, with advantages like high energy density, an already available market and infrastructures.

 “The current situation of e-fuel production technologies for aviation applications and their implementation at the national level will be studied, and some plant configurations identified with related economic analysis to estimate specific production cost, according to electricity and CO2 prices in the ETS emissions market”, pointed out Claudia Bassano, researcher at the ENEA Laboratory of Energy Storage, Batteries and Technologies for Production and Use of Hydrogen of the Division of Energy Production, Storage and Use.

Currently, e-kerosene production consists of a two-stage process which, through the Fischer-Tropsch reaction, produces a raw emulsion composed of multiple hydrocarbon fractions followed by a refining stage. ENEA will work at developing a single-stage process capable of obtaining the new jet fuels. The experimental activity will be conducted in a pilot plant and the data collected used in a commercial process simulator to optimize the production process both in terms of plant layout and operating conditions.

 “E-fuels, chemically similar to fossil fuels, are carbon-neutral when produced from renewable hydrogen, but they still have high production costs that can reach 5 €/ldeq (litre of diesel equivalent)”, said Monteleone.