It's bad enough for some propeller aircrafts to be explained as being powered by rubber bands. Now the skeptics could start having a dig at flying on whatever from cooking oil to liquefied algae.

With the civil aviation industry under increasing pressure from rising oil prices and environmental legislation, the race is on to discover viable alternatives to traditional kerosene and these so far seem to boil down to various kinds of biofuel.

Not remarkably, the first trials of alternative fuel were initiated by British aviation leader, Sir Richard Branson, whose Virgin Atlantic began London to Amsterdam flights with minimal biofuel usage in 2008. This was quickly followed by Lufthansa and Air New Zealand who each used various blends of routine fuel and bio derivatives consisting of some from made from jatropha which can grow in soil considered too poor for growing mainstream foodstuffs.

jatropha curcas is a genus of approximately 175 succulent plants, shrubs and trees (some are deciduous, like Jatropha curcas), from the family Euphorbiaceae.

In 2007 Goldman Sachs pointed out Jatropha curcas as one of the very best candidates for future biodiesel production. It is resistant to drought and insects, and produces seeds consisting of 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aeronautical major Embraer and the Sao Paulo state Research Support Foundation transferred to carry out research and advancement into making use of biofuels to power jet airliners. It was reported that Brazilian airline companies Azul, Gol, TAM and Trip would act as strategic specialists for the project.

The latest airline company to begin experimenting with new fuels is the Alaska Air Group which has carried out internal US flights using a blend of 80 % petroleum based fuel and 20% biofuel made from cooking oil. This mix, it is claimed, can cut damaging emissions by 10%.

One actually encouraging advancement has actually been the relocation away from biofuels which compete head on with food customers thereby avoiding a rate spiral. Not so long ago, a rise in use of biofuels in automobiles triggered a spike in maize prices as US farmers diverted excessive corn to fuel processing.

Hopefully in the future, airlines and drivers will focus biofuel usage on non-food sources such as jatropha and algae. It would be a mixed blessing undoubtedly if some people ended up starving just to please somebody else's green qualifications.