Aviation biofuels powering commercial flights nears reality as technical standards body passes approval
(photo: Continental Airlines)
Tue 14 June 2011 – A major technical milestone has been reached in the introduction of renewable aviation biofuels as the main standards body responsible for certifying fuels has granted preliminary approval for their use in commercial operations after a ballot by a committee of industry, air force and regulatory stakeholders was unanimously passed. Final approval is expected at the beginning of July with technical specifications for bio-derived fuel then being added to the existing D7566 alternative fuel specification. Plans to start using biofuels in the prescribed 50 per cent blends have been stalled since a similar ballot six months ago unexpectedly threw up concerns over an engine test contamination issue, which have now been overcome. Lufthansa has ambitions to be the first airline to use blended biofuels under commercial flying conditions and is now awaiting the rubber-stamping before commencing a programme of regular daily flights.
Barely five years ago there were considerable doubts within the aerospace sector that biofuels would be up to the task of meeting the particularly high specifications demanded for the challenging operating conditions and requirements of modern jet engines. Following the certification of synthetic alternative fuels derived using Fischer-Tropsch technology two years ago, a technical subcommittee of US-based standards body ASTM International has now concluded that jet fuel derived from renewable biomass is safe to use as a drop-in fuel in 50/50 blends with conventional jet kerosene.
Formerly referred to as Hydrotreated Renewable Jet (HRJ) or Bio-derived Synthetic Pariffinic Kerosene (Bio-SPK), fuel derived from crops such as jatropha or camelina has been given a new name, Hydroprocessed Esters and Fatty Acids (HEFA), by ASTM.
Instrumental in the certification process has been the US Federal Aviation Administration (FAA), with FAA Aviation Fuels Specialist Mark Rumizen playing a key role on the ASTM subcommittee.
Explaining the ASTM approval process, Rumizen told GreenAir Online: “The revision of D7566 has successfully passed the first two levels of balloting, the ASTM D02.J subcommittee ballot and the ASTM D02 Main Committee ballot. This represents the successful completion of a rigorous and thorough technical review of the proposed specification revision.
“ASTM holds the ballot until the end of the month to make sure that there are no additional comments, concerns or other requests for additional review and debate. This is called the ASTM Society Review period. Almost without exception, no further comments are submitted during the Society Review period, so the ballot is considered effectively passed after the committee level ballot. At the end of June, there exists no further opportunity to comment on the ballot and ASTM considers the specification revision passed.”
Commenting on news of the breakthrough, FAA Administrator Randy Babbitt said: “This is a significant step towards a new era of greener and more energy-independent air travel. We anticipate publication of a standard in the next few weeks will open the door for production of commercial aviation biofuels that can be used without changing aircraft systems or airport fueling infrastructure.
“This is a key milestone in helping us meet the Obama Administration’s environment and energy goals for the nation and it is directly responsive to the recommendation of the Future of Aviation Advisory Committee to promote and display US aviation as a first user of sustainable alternative fuels.”
However, Europe’s leading carrier Lufthansa is likely to steal a march as it is now just awaiting final approval before it formally announces when its Burnfair project will get fully underway with plans to fly up to four times a day on commercial flights between Hamburg and Frankfurt on an Airbus A321. An initial consignment of biofuel has already been supplied by Finland’s Neste, although a Lufthansa spokesman declined to reveal the type of biomass that has been sourced for the fuel.
A key input into the ASTM process has been the support work of the US-driven Commercial Aviation Alternative Fuels Initiative (CAAFI) and its members. Nicholas Calio, President and CEO of the Air Transport Association (ATA), which helped co-found CAAFI in 2006, said: “The committee endorsement of this specification is significant for all consumers of jet fuel, bringing the airline industry one step closer to widespread production of cleaner, alternative fuels that will help meet our environmental goals while enhancing the security and competitiveness of our energy supply.”
According to ATA, CAAFI and the aviation fuel community will now explore other alternative fuel pathways, including the development and approval of processes that convert sugars and lignocellulosic (renewable organic material from, for example, bagasse and corn stover) feedstocks to jet fuel.