It's bad enough for some prop airplanes to be referred to as being powered by rubber bands. Now the skeptics could begin having a dig at industrial aircraft flying on whatever from cooking oil to liquefied algae.

With the civil aviation market under increasing pressure from rising oil prices and ecological legislation, the race is on to find viable alternatives to standard kerosene and these up until now appear to come down to various types of biofuel.

Not surprisingly, the very first trials of alternative fuel were started by British aviation pioneer, Sir Richard Branson, whose Virgin Atlantic started London to Amsterdam flights with restricted biofuel use in 2008. This was rapidly followed by Lufthansa and Air New who each used various blends of routine fuel and bio derivatives consisting of some from made from jatropha curcas which can grow in soil considered too bad for growing mainstream foods.

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

In 2007 Goldman Sachs pointed out Jatropha curcas as one of the very best candidates for future biodiesel production. It is resistant to dry spell and insects, and produces seeds including 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 study 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 experts for the project.

The newest airline to start try out 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 mixture, it is claimed, can cut hazardous emissions by 10%.

One truly encouraging development has actually been the move far from biofuels which complete head on with food customers therefore avoiding a rate spiral. Not so long earlier, a surge in usage of biofuels in cars and trucks caused a spike in maize costs as US farmers diverted too much corn to fuel processing.

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