On Wednesday, US-based carrier United Airlines made history in the aviation history when it flew the first commercial aircraft using 100% sustainable fuel in one of two engines.

The flight operated from Chicago's O'Hare airport to Washington.

"Aviation history is cleared for takeoff. The world's first passenger flight using 100% sustainable aviation fuel (SAF) is en route to @Reagan_Airport," the company said in a tweet.

The jet engine of the aircraft was fuelled with non-petroleum feedstocks, which unlike petroleum use leftovers from agriculture, wood mills and other sources.

According to the company, one of United's new Boeing 737 MAX 8 planes, carrying 100 passengers, flew with 500 gallons of sustainable fuel in one engine and 500 gallons of regular jet fuel in the other. Sustainable aviation fuels offer the ability to match the performance of petroleum-based jet fuel while emitting a fraction of the CO2.

"Today's (Dec 1) SAF flight is not only a significant milestone for efforts to decarbonize our industry, but when combined with the surge in commitments to produce and purchase alternative fuels, we're demonstrating the scalable and impactful way companies can join together and play a role in addressing the biggest challenge of our lifetimes," United CEO Scott Kirby said in a statement as reported by ANI.

The fuel was supplied by World Energy, North America's only commercial biofuel producer.

United Airlines said it agreed to purchase nearly twice as much sustainable aviation fuel as any other airline.

Image courtesy: ANI