GEAR & TECH

Greek yogurt could be a new sustainable jet fuel

When companies mass-produce Greek-style yogurt, there's a significant output of what they call "waste" product. The acid whey — milk sugar, fructose, and lactic acid — is still edible, but it's not used in the product. Researchers have found that a few modifications to the whey can turn it into a fuel for jet engines.


In an attempt to discover a natural antibiotic for livestock, scientists added carbon elements to the waste product to make a biofuel — and a sustainable fuel for jet engines.

When the yogurt is produced, the protein is strained from milk, leaving behind a watery liquid whey. The mixture of acids and sugars is prime food for certain kinds of bacteria. As the bacteria feed on the acid whey in an oxygen-deprived environment, they create caproic acid and caprylic acid, a kind of "bio-oil."

"Excuse me sir, did you want regular or unleaded?"

The process is the same as what goes on in the human stomach. The bacteria in human stomachs convert food into different acids, which fuel the body.

The dairy sector of the agricultural market has what Cornell researcher Dr. Lars Angenent calls, "a very large carbon footprint." His work is focused on creating closed, sustainable cycles of production. The researchers added bacteria to the waste product to create a natural antibiotic for cattle.

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Angenent's team created two "open-culture" reactors, featuring bacteria feasting on the waste products at two different temperatures and extracting the flammable gas given off. The team's next step is to scale-up the reactor's size and create changes that increase both the efficiency of the reactions and how the oil is collected.

Once that process is more economical, the bio-oil production could become a sustainable source of fuel. At the same time, it will make the agricultural sector more profitable and less wasteful.