The owner of Virgin Atlantic (actually all of Virgin) Richard Branson has been perusing the use of biofuels for airplanes. Although there are many skeptics, Branson hopes to fly a jet using solely biofuel by the end of 2008. Biodiesel does run signifigantly cleaner than the use of traditional fuels, but a few (major) problems (like crashes) remain.
?Since biodiesel is so similar to regular diesel oil, an engine that runs on one will hardly notice the difference if you switch it. This is the reason that alternative fuel enthusiasts are so gung-ho about it; There are no heaters, tanks, tubes, or filters to install. Just fill up your tank. But if your car craps out on biodiesel, all that happens is you stop on the road.
There are some easier ways that could be used now to increase the efficiency of air travel, for example,
We are also looking at future technologies and with our aircraft the Virgin Atlantic Global Flyer we proved that an all carbon composite high altitude jet could indeed operate safely at very high altitude above the tropopause and improve fuel efficiency dramatically. The plane is now in the Smithsonian Institute in Washington DC but before it went there, Steve Fossett successfully flew it around the world on less fuel per hour than an American SUV 4�4 vehicle!
If you fly often and are concerned about the carbon emissions, you can look into alternative ways of traveling (train, car, bus). If that reasonable you can always offset your carbon emissions.
It’s more likely to be a kind of kerosene produced from wood chips or other renewable sources than ethanol or diesel, both of which would probably freeze at the low temperatures planes fly through at high altitudes.