UC Berkeley looks back to an old (and abandoned) method for making explosives and tweaks it to make renewable biofuels:
Campus chemists and chemical engineers teamed up to produce diesel fuel from the products of a bacterial fermentation discovered nearly 100 years ago by the first president of Israel, chemist Chaim Weizmann. The retooled process produces a mix of products that contain more energy per gallon than ethanol that is used today in transportation fuels and could be commercialized within 5-10 years.
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The late Weizmann’s process employs the bacterium Clostridium acetobutylicum to ferment sugars into acetone, butanol and ethanol. [Harvey Blanch and Douglas Clark, professors of chemical and biomolecular engineering,] developed a way of extracting the acetone and butanol from the fermentation mixture while leaving most of the ethanol behind, while [Dean Toste, professor of chemistry,] developed a catalyst that converted this ideally-proportioned brew into a mix of long-chain hydrocarbons that resembles the combination of hydrocarbons in diesel fuel.
Tests showed that it burned about as well as normal petroleum-based diesel fuel.
“It looks very compatible with diesel, and can be blended like diesel to suit summer or winter driving conditions in different states,” said Blanch.