Maybe not as exotic as the possibility of avgas made from saltwater plants, but promising nevertheless. Especially as it already works and has existing air miles to its credit. Aeroalcool of Brazil are in the throes of seeking certification for conversion of aircraft engines to run on the same bagasse (sugar cane waste) derived ethanol that drives the country’s flex-fuel cars. Their first customer seems to have been fellow Brazilian, the aircraft manufacturer Embraer, who have been selling their propeller based Ipanema cropduster with the engine (pic above). Pier and Cessna conversions are also being considered. Once converted it seems that a 20% power boost can be realised, and with minor adjustments the engine can still also use regular aviation petroleum, should ethanol not be available. As noted in our much loved thread on biodiesel airplanes, (where a savvy reader does mention these Brazilian aircraft) Biodiesel suffers from freezing problems at high altitude, but Aeroalcool reckon their engines allow ethanol to operate hassle free up to 20,000 feet (6,000 m), well, in tropical and subtropical regions anyhow. From a green perspective they suggest that using ethanol over avgas is next to carbon neutral, increases engine life whilst adding power output, the fuel is produced locally within Brazil (and is up to a fifth cheaper than normal avgas.) supporting local employment and reducing oil transportation. (And yeh, the irony of this green technology being rolled out via a crop duster used for spraying petroleum based pesticides is not lost on us.) ::Aeroalcool, via Wikipedia.
Oh, and we probably should mention that the ethanol fuelled Ipanema
picked up an Scientific American magazine award as one of the 50 best inventions of 2005. The same year that it also won the Flight International Aerospace Industry Award in the General Aviation category.