‘Blue whirl’ fires could help oil spill clean-up

When spills occur at sea, oil is often corralled into thick layers on the surface and then burned. According to the researchers, however, the result is an inefficient and smoky fire with high levels of emissions. Even when yellow fire whirls occur, they don’t burn fuel at maximum efficiency, their colour indicating a lack of oxygen.

“The yellow colour is due to radiating soot particles, which form when there is not enough oxygen to burn the fuel completely," said Maryland engineer Elaine Oran, co-author of the paper, which appears in Proceedings of the National Academy of Sciences. "Blue in the whirl indicates there is enough oxygen for complete combustion, which means less or no soot, and is therefore a cleaner burn."

The researchers discovered the blue whirl while studying the combustion dynamics of fire whirls on water, something they claim hadn’t been done before for practical applications. While creating the vortices in a lab is challenging, instigating them at sea would be even more difficult, and potentially extremely dangerous. But if they could be controlled, they would provide a much cleaner method of dealing with surface oil than currently exists.