Continental Airlines recorded a 1.1% improvement in fuel efficiency over traditional jet fuel during an alternative fuel demonstration on 7 January.
Houston-based Continental used a 50:50 mix of Jet A1 and biofuel derived from 95% jatropha oil and 5% algae oil to power one of two CFM International CFM56-7B engines on a Boeing 737-800 during the roughly 90-minute test flight.
"The biofuel blend performed as well as or better than traditional jet fuel", the carrier says in a statement today.
During the Houston trial, Continental recorded various flight parameters and ran acceleration and deceleration checks, two inflight engine shut-downs and restarts -one wind milling start and one starter assist -and a simulated landing and go-around, says Continental flight test captain Rich Jankowski.
The aircraft also simulated the highest, most difficult altitude the airline flies, Quito in Ecuador, he adds.
Other earlier findings include the thrust setting of the engines was the same, but fuel flow and exhaust gas temperature was slightly less for the engine using the biofuel blend, Jankowski says.
The biofuel-blend-powered engine-the No. 2 engine-burned slightly less fuel than the engine powered by Jet A for the same thrust setting, Continental manager of training standards captain Jackson Seltzer explains.
The right engine used 3,600lbs of the biofuel blend and the left engine burned 3,800lbs of jet fuel, he says.
Both fuels emitted roughly the same amount of CO2 inflight, but overall greenhouse gas emissions savings were realized during the production of the biofuel, which, unlike Jet A, absorb CO2, Continental chairman and CEO Larry Kellner previously said.
The airline is now focused on helping to move forward the certification process for biofuels.
Certifying body ASTM International, a voluntary standards development organization, will meet this month to discuss specifications for non petroleum-based fuels but ASTM is not expected to approve specifications for 50:50 biofuel blends until next year.
"[W]e hope to see these fuels produced in commercial quantities in the near future," Continental's managing director of global environmental affairs Leah Raney says.
Continental, along with Air New Zealand (ANZ) and Japan Airlines (JAL), conducted separate biofuels demonstrations between December 2008 and January 2009.
Scientific testing of the alternative fuel used by ANZ has found that a Boeing 747-400 using the 50:50 biofuel blend of Jet A1 and jatropha oil could improve fuel burn by 1.2% during a 12-hour flight covering 5,800 nautical miles.
Testing also found that using the blend could save 1.4 tonnes of fuel during a 12hr flight and the biofuel blend could also improve fuel burn by 1% on shorter range flights.
JAL rounded out the demonstrations by operating a biofuel consisting of oils from the flowering plant camelina (84%), jatropha (under 16%) and algae (under 1%) to fly a Pratt & Whitney JT9D-powered 747-300 during a 1hr flight over Tokyo.
JAL has not yet released specific results.