Lufthansa has launched the world's first regular scheduled commercial flights powered by biofuel.
For six months, a Lufthansa Airbus A321 will fly four rotations a day on its normal Frankfurt-Hamburg scheduled service with 25% of the aircraft's power provided by biofuel.
Lufthansa says it intends this to be a carefully controlled trial for its biofuel operations as well as a commercial venture.
The aircraft flying the route for the trial period is airframe D-AIDG, a recently-delivered A321 powered by new International Aero Engines V2500s.
For all these flights its right engine will be fed a 50:50 mix of ordinary kerosene and synthetic fuel derived from sustainably produced biomass, and the left engine will be powered by normal jet fuel.
The purpose will be to monitor the relative engine performance, fuel consumption throughout the trial, and to be able to observe whether, after six months, there is any difference in the condition of the two engines.
Airbus and IAE are partnering Lufthansa in this venture, as is Finnish fuel manufacturer Neste Oil. The fuel itself was certificated for commercial use on 1 July, and has been approved both by the European Aviation Safety Agency and the US FAA.
The biofuel is based on jatropha, camelina and animal fat. Airbus explains that it is a biomass-to-liquid blend of hydro-processed esters and fatty acids, and Lufthansa says the source is a combination of "plant oils and animal waste" the origins and production of which have also been researched for sustainability.
At present the maximum permitted biofuel mix for commercial flights is 50%, and that is what Lufthansa is using for the trials.
The airline says that the present price of the biofuel is twice that of ordinary aviation kerosene, but it is necessary for aviation to start down the sustainable fuels route for climate change reasons, but also because mineral oil is a finite resource that will become more expensive while biofuel will become relatively less costly.
"Since biokerosene has similar properties to those of conventional kerosene it can be used for all aircraft types without any need for modifications to the aircraft or its engines," said Lufthansa.
The carrier estimates the cost of the trial will be €6.6 million ($9.3 million), of which €2.5 million is being supplied by the German ministry of economics as part of a programme known as FAIR (future aircraft research), which is examining biofuel compatibility and the used of liquefied natural gas in aviation among other projects.
Lufthansa's first flight departed as LH013. Using biofuel for the trial period will cut carbon dioxide emissions by up to 1,500t, the airline claims.