Researchers accidentally discovered a new type of blue fire that could prove valuable when cleaning up major oil spills.
The fire was detected while researchers investigated uses for fire whirls, also known as firenados.
Faculty members from the University of Maryland's A. James Clark School of Engineering were initially working to understand the burning dynamics of fire whirls on water. During their experiment, they discovered an eco-friendly "blue whirl," which had transitioned from a standard yellow flame.
The optimal, clean burning of the blue fire could be valuable when it comes to cleaning up oil spills and meeting worldwide demand for high-efficiency, low-emission combustion, the researchers said.
"A fire tornado has long been seen as this incredibly scary, destructive thing, but, like electricity, can you harness it for good? If we can understand it, then maybe we can control and use it," Michael Gollner, assistant professor of fire protection engineering and co-author of the paper, said in a statement.
He said this is the first time fire whirls have been studied for practical applications.
"Fire whirls are more efficient than other forms of combustion because they produce drastically increased heating to the surface of fuels, allowing them to burn faster and more completely. In our experiments over water, we've seen how the circulation fire whirls generate also helps to pull in fuels," Gollner said.
One of the the current oil spill remediation techniques is to gather crude oil into a thick layer and burn it in place on the water. However, that process is seen as inefficient and incomplete, and it also releases lots of smoke into the air.
"Blue in the whirl indicates there is enough oxygen for complete combustion, which means less or no soot, and is therefore a cleaner burn," Dr. Elaine Oran, a Glenn L. Martin Institute professor of engineering and co-author of the paper, said.
The standard yellow color of fire whirls is due to emissions by radiating soot particles. Oran added that soot forms when there is not enough oxygen present to burn the fuel completely.
The group will now seek additional support to continue further testing to determine if they can develop controlled fire whirls on a larger size and scale. The height of the blue whirl in the lab was only about 4-8 cm, while the yellow fire was over 60 cm.
"If we can achieve a state akin to the blue whirl at larger scale, we can further reduce airborne emissions for a much cleaner means of spill cleanup," Gollner said.
Oran admitted that since the blue firenado is so new, there is still much to understand, including if the size of the fuel source will affect the size of the blue whirl.
"We have a lot of theories, but no hard evidence, except that we managed to see something that absolutely blew our minds," she said.
The researchers published their findings in a paper published in the peer-reviewed journal, "Proceedings of the National Academy of Sciences," earlier this month.
Oran told AccuWeather that it's possible that the blue fire whirl has been discovered before, but there are no prior references in past literature. One of the reasons they wanted to publish the paper was to see if anyone had made a similar discovery. They showed the paper to other experts and brought it to the International Symposium on Combustion, but no one reported any prior encounters.
"As far as we can tell, it's essentially new," she said.
The firenadoes that occur in nature can grow to be several hundred feet in height. They are generated when an active fire is swept upward, creating a vortex.
"The heat of the fire rising through the air allows the vortex to strengthen and create the firenado," AccuWeather Meteorologist Eric Leister said.
A firenado can then bring in more brush and debris and fuel itself further.