The clear liquid at the top of the vial extracts the acetone and butanol, separating the chemicals from the fermenting brew while protecting the bacteria, which are killed by high concentrations of the chemicals (Photo: Robert Sanders, UC Berkeley)
Graduate student Zachary Baer works with a fermentation chamber to separate acetone and butanol (clear top layer) from the fermented brew at the bottom (Photo: Robert Sanders, UC Berkeley)
Researchers at the Energy Biosciences Institute (EBI) are generating bio fuels from renewable sources, such as sugar and starch, using a process that could be commercialized in as little as five to ten years. Although the fuels are currently more expensive to produce than those made from petroleum, they contain more energy per gallon than ethanol and the researchers say that, if adopted, could help to cut greenhouse gas emissions from transportation.
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