It's bad enough for some propeller airplanes to be described as being powered by rubber bands. Now the cynics might begin having a dig at industrial aircraft flying on whatever from cooking oil to melted algae.

With the civil air travel industry under increasing pressure from rising oil costs and ecological legislation, the race is on to find practical alternatives to traditional kerosene and these so far seem to come down to various types of biofuel.

Not surprisingly, the first trials of alternative fuel were started by British aviation leader, Sir Richard Branson, whose Virgin Atlantic started London to Amsterdam flights with minimal biofuel use in 2008. This was quickly followed by Lufthansa and Air New Zealand who each utilized different blends of routine fuel and bio derivatives consisting of some from made from jatropha curcas which can grow in soil thought about too bad for growing mainstream foods items.

jatropha curcas is a genus of roughly 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 best candidates for future biodiesel production. It is resistant to dry spell and bugs, and produces seeds consisting of 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aerial significant Embraer and the Sao Paulo state Research Support Foundation moved to perform research and development into using biofuels to power jet airliners. It was reported that Brazilian airline companies Azul, Gol, TAM and Trip would act as tactical specialists for the task.

The most recent airline company to start try out brand-new fuels is the Alaska Air Group which has performed internal US flights utilizing a mix of 80 % petroleum based fuel and 20% biofuel made from cooking oil. This mix, it is claimed, can cut hazardous emissions by 10%.

One truly encouraging development has actually been the move far from biofuels which compete head on with food consumers thereby avoiding a cost spiral. Not so long back, a rise in use of biofuels in cars and trucks triggered a spike in maize costs as US farmers diverted too much corn to fuel processing.

Hopefully in the future, airlines and drivers will focus biofuel consumption on non-food sources such as jatropha curcas and algae. It would be a mixed blessing indeed if some individuals wound up starving just to satisfy somebody else's green qualifications.