A company in New Zealand flew a 747-400 with one engine using a 50-50 blend of JetA and an oil that comes from the jatropha plant.
This is really really big news. Bio-fuels are very difficult to blend in to aviation because... well... In most cases the engines are very old and can not handle fuels that they were not designed for. Also, probably most important, most bio-fuels freeze at the altitudes that most jets have to fly at.
You see, the jet engine is not a very efficient engine at altitudes under 20,000 feet. They suck lots and lots of fuel going through the thick air. So they climb up to where the air is thin and very cold.
Apparently the jatropha plant oil has a lower freezing temperature than JetA, so no worries about freezing!
This is also big news to General Aviation. Why? Because more and more new airplanes are using turbo diesel engines. They don't use auto diesel fuel, that stuff gells up and is very heavy. Aviation diesels use JetA. If a bio-fuel can be found that replaces JetA, that means that General Aviation has a new fuel to focus on.
Oh, and as you probably know... I don't give a crap about the carbon BS that the company is slinging. What I do care about is sustainability and reducing the amount of oil that comes from unfriendly sources. We can grow this jatropha plant here in the U.S. We can produce it here in the U.S. If the use of this 50-50 blend becomes common place, we have just reduced our reliance on unfriendly oil by that much. That is very cool.