Air Transport

Fuel hybrids that blend Jet A with biofuels in a 50:50 split could bring efficiency improvements in the range of 1-2%, and use of the biofuel camelina could offer an 80% CO² reduction over its lifecycle, according to Boeing.

The airframer has published a report about ground and flight tests conducted between 2006 and 2009, titled Evaluation of bio-derived synthetic paraffinic kerosene (Bio-SPK). The report says the test fuels "performed as well as or better than typical petroleum-based Jet A".

Flight tests were carried out using a Rolls-Royce-powered Air New Zealand 747-400, a CFM-powered Continental 737-800 and a Pratt & Whitney-powered Japan Airlines 747-300. The ANZ flight used fuel derived from jatropha, while the Continental flight's fuel mixed jatropha and algae.

Three feedstocks featured in the JAL flight's fuel: jatropha, algae and camelina. Freeze points were found to be lower than required and net heat of combustion higher, meaning greater thrust could be achieved from a given fuel burn.

Speaking at a show briefing, Boeing Commercial Airplanes managing director of environmental strategy Bill Glover said camelina "could be the first available" as it can be grown in temperate climates as a rotation crop. Taking the feedstock's production into account, CO2 reductions of 50-80% are possible, claimed Glover. Meanwhile, high-volume production of jatropha is two to four years away due to complications in mechanical harvesting of seedpods.

Glover singled out algae as a "very promising" feedstock but admitted that scale production was probably eight to 10 years away.

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