Sugar is classically one of the very worst things you can put in a car’s gas tank but that has not stopped Audi from exploring ways to make biofuel made from the sweet powder. The German automaker has teamed up with the French company Global Bioenergies to make synthetic gasoline derived from sugar. The pair claim their process is faster and cheaper than other biofuels. What’s more, the resulting bio-isooctane doesn’t require any car modifications, which makes it an easy replacement fuel for regular gasoline-burning automobiles.
As with other biofuel production processes, Global Bioenergies ferments the sugar into fuel using microorganisms. To do this the scientists genetically engineered E. coli bacteria, which eats sugar and produces isobutene gas as a byproduct. In most biofuel processes, once fermentation raises the ethanol level to 12 per cent, it starts to poison the microorganisms, preventing them from making any more fuel.
However, because the fuel rises as a gas, the concentration in the fermentation tank never reaches toxic levels. This allows the bacteria to keep converting sugar into more fuel for a longer period. Supposedly this same process can be adapted for use with other foods like corn, sugar cane, and other biomasses heavy in glucose such as wood chips.
After this the isobutene is filtered to separate other gaseous substances like carbon dioxide. The scientists say working with gases is cheaper and less energy intensive than distillation. The resulting bio-isobutene fuel works in any everyday car without any modifications. On top of using the fuel on its own, it could be mixed with conventional gasoline.
Global Bioenergies has already demonstrated its technology in the lab and is now building two pilot facilities to produce bio-isobutene. It’s expected that the larger of the two pilot facilities will produce over 100,000 liters of biofuel a year. Meanwhile, Audi has formed a partnership to help fund the company’s rollout as this technology could help its vehicle lineup as well as cars from all the automakers.
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