Lufthansa is evaluating the use of alcohol-based biofuel, which could reduce costs versus existing renewable fuel production methods.
Together with US biofuel specialist Gevo and the German army’s materials research laboratory, the airline is assessing a production process – dubbed “alcohol to jet” (ATJ) – whereby “mainly plant waste” is used to distil kerosene, the airline says.
The plant waste is thus fermented to form isobutanol, which is then dehydrated and converted into kerosene, using standard refinery processes.
If approved, a “wide range” of feedstocks could be employed for the production of alcohol-based kerosene, Lufthansa says. While the method is “as versatile” as the approved Fischer-Tropsch process that is used to convert biofuel feedstock into hydrocarbons, the ATJ route requires “much lower initial investment”, the airline adds.
Gevo will provide the alcohol-based fuel for the EU-funded project, while the Bundeswehr’s Research Institute for Materials, Fuels and Lubricants will assess the biokerosene’s blending capability with conventional Jet A1.
The blending capability is a crucial characteristic that must be determined before further assessment. Lufthansa expects that ATJ fuel can be mixed with Jet A1 up to the current maximum 50:50 blending ratio.
At this stage, Lufthansa’s role is to co-ordinate the project, with the army laboratory acting as research contractor. If, however, the latter's assessment is successful, the next step would be to trial the biofuel in engine ground tests, the airline says.
It adds that the aim is to gain approval for the ATJ as bio-kerosene by year-end.