Offshore oil spills have caused some of the worst manmade disasters in history. And while adding a vortex of fire to the mix might sound like the opposite of a good solution, new research has found it might be the best way to clean up our mess.
When dealing with major oil spills, emergency responders often ignite slicks on the ocean’s surface, creating ‘in-situ’ fire pools that stop the oil from spreading further.
But while this protects the marine environment, such fires send huge plumes of smoke and toxic soot into the atmosphere.
Taking inspiration from a freak 2003 incident in Kentucky – where a bourbon spill sent 800,000 gallons up in flames, twisting into a 30m (100ft) fire whirl on a lake – Prof Elaine Oran and her team began to wonder whether the same process could be harnessed for good.
“We were joking about how it must have smelled,” she told BBC Science Focus. “Then we looked carefully at what was happening. Larger fire whirls were pulling in and eating up smaller fire whirls, actually pulling them in and absorbing them.”
So the team constructed a 4.8m-tall (16ft), three-walled triangular structure at a fire training facility in Texas, with a pool of crude oil floating on water at its centre. When ignited, it produced a roaring, nearly 5.2m (17ft) fire whirl.
Compared to conventional fire pools, it burned through oil 40 per cent faster, cut soot emissions by 40 per cent, and consumed up to 95 per cent of the fuel.
The secret is in the spin. Rather than spreading outward, the vortex sucks in oxygen from all sides – burning hotter and more completely, like a giant incinerator rather than a bonfire.
But harnessing that power is easier said than done. Fire whirls are temperamental; too much wind and the column collapses, too little airflow control and it reverts to a conventional fire pool.
Fire whirls are temperamental, though; too much wind and the column collapses, too little airflow and it reverts to a fire pool. Despite this, Oran said achieving the ‘Goldilocks Zone’ in the field is “very realistic”, and envisions mobile barrier structures deployed directly over spills at sea.
“This study is more than just an experiment, it’s a glimpse into a future where fire isn’t a force of destruction, but a tool to protect our oceans and planet,” she said.
The results were published in the journal Fuel.
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