Aircraft

Virgin/Boeing partnership to test alternatives to kerosene 747-400

Virgin Atlantic is to hold a joint biofuel demonstration with Boeing, Virgin Fuels and engine maker GE Aviation on one of its Boeing 747-400s during 2008 - the first-ever attempt by an airline to develop sustainable fuel sources suitable for use on commercial jet engines.

News of the ground-breaking environmental partnership came as Virgin ordered 15 Boeing 787-9s - the largest order yet for the type by a European airline - because it burns around 27% less fuel per passenger than the A340-300 that it will replace within the Virgin Atlantic fleet.

Virgin Atlantic says it will be testing eight different types of alternative fuel until the end of the year on a ground-based engine. "Each will be thoroughly tested until we find one that works on the ground. This will then be selected as the one which may be worth pursuing, but it is not going to be an overnight process," says Virgin.

The carrier says likely candidate fuels to be tested would include soya- and vegetable-based biofuels and butanol - but not ethanol - and that the selected choice would be tested on one engine in a 40-50% mix with standard kerosene.

GE Aviation says Boeing will receive the biofuel through Virgin before conducting screenings for thermal stability, viscosity and distillation properties. GE will then evaluate and analyse the fuel for compatibility with a turbofan engine before it is flown on a CF6-powered 747-400.

Boeing fuel expert Dave Daggett says algae could be a long-term candidate as a viable alternative aviation fuel although early tests may use biofuels derived from either soya or rapeseed: "We might use them initially just to prove they can work, but the large amount of land required to produce this as an alternative fuel and the carbon dioxide footprint generated during the production process will be important factors to take into consideration."

Shell Aviation fuel specialist Mike Farmery agrees: "At the moment it is not clear where the best solution lies. Much of the industry has focused on producing a hydrocarbon fuel that will be a drop-in replacement to mix with standard kerosene. This way operating procedures and equipment will not have to be changed for a special fuel."

He adds: "Two processes that are in the frame at the moment are the Fischer-Tropsch biomass to liquids and hydrogenation of vegetable oils. Both have their pluses and minuses but they can both, in principle, produce high-quality hydrocarbon fuels.

"It must be said that there are very many technical hurdles to overcome with algae although the added advantage of the algae technology is that you can use it to sequestrate carbon dioxide so if you can make the technology work, you get a double bonus."

Visit flightglobal.com for an exclusive interview with Boeing's Dave Daggett on algae's potential to eliminate aviation's contribution to global warming