Mesmerizing 'blue whirl' from fire tornado could be cleaner solution for oil spills

Scientists at the University of Maryland have discovered a "blue whirl" — a pure blue flame that produces less pollution than a yellow flame when it's ignited over fuel.

Scientists discover clean-burning blue flame while simulating a fire tornado in the lab

Flame goes from raging 'fire whirl' to calm 'blue whirl'

6 years ago
Duration 0:22
While simulating a wildfire tornado, researchers at the University of Maryland discovered a small, stable, blue flame that burns clean. They're hoping this "blue whirl" could one day be used to clean up oil spills.

A mesmerizing pure blue flame that spins like a top could be the clean burn needed to mop up oil spills in oceans, lakes and rivers.

The "blue whirl" was accidentally discovered by a team of American scientists while they were simulating a controlled fire whirl or fire tornado — a violent and destructive weather event that can form during wildfires, such as one recently blamed in the death of an Alberta pilot.

Elaine Oran, a professor of aerospace engineering at the University of Maryland, said she and her colleagues decided to light their lab on fire after watching some "fabulous" footage of a fire whirl on YouTube.

The video featured the inferno forming over a lake in Kentucky next to a Jim Beam factory. 

You know where this is going.

Somehow a vat of bourbon from the factory had spilled and seeped into the lake. Ignited by a lightning strike, the fire tornado grew, "swirling around, getting bigger and bringing all of the alcohol towards it," said Oran.

It was sucking the Jim Beam off the surface of the water and burning it up.

"And almost simultaneously, we said 'remediation.'"

The experiment

That prompted Oran and her colleagues to further study how fire whirls burn over water laced with fuel.

When they recreated the phenomenon in the lab, Oran says the fire whirl erupted into an angry column of yellow flames.

But then it transitioned into what she described as a small and stable "beautiful blue flame" — the blue whirl.

Taken from a high-speed video, the frames show a lab-simulated fire whirl transitioning from a yellow whirl to a blue whirl. (University of Maryland)

Oil and fire

Controlled burns are already used as a remediation tool for oil spills in the Gulf of Mexico. Problem is, they produce black, polluting plumes of smoke.

Oran said that's a sign that the fire does not have enough oxygen to burn the fuel completely. However, when a fire whirl transforms from yellow to blue, it becomes a "cleaner burning" hydrocarbon flame. 

"More of the soot was burned up," she said. "So we thought it would be interesting to quantify how good, or how much better, fire whirls might be than just a regular fire for cleaning up oil or other things on the surface."

The team's results have been published in the the peer-reviewed journal Proceedings of the National Academy of Sciences.

Harnessing the blue whirl

"I think it could be done, I really do," Oran told CBC's Calgary Eyeopener on Monday.

But first, she and her colleagues must figure out what conditions are needed to create a blue whirl, and whether it can be replicated with various types of fuel.

Also, they have to understand how to control it.

"It would be very nice to recreate one of these little blue whirls without having to go through the fire whirl stage — which is so dangerous."

With files from CBC's Calgary Eyeopener