Microbubbles method benefits biofuel production

Microbubbles of around 50–500 microns in diameter are highly valued for gas and energy transfer due to their considerable surface area per unit volume.

They are not a new invention but Sheffield University spin-out Perlemax has patented a novel fluidic oscillator to create them more efficiently.

Perlemax founder and engineering professor Will Zimmerman said: ‘Basically we push gas just enough to displace the water needed to create the interface and the bubble. The concept is you use a packet of gas about the same size as the pore and the result is that you get a bubble about the same size — the smallest we’ve gone down to is an average of 28 microns.

‘It’s hard to imagine you could come up with a more energy-efficient way of making bubbles of those sizes.’

Alternate methods revolve around compressing gases into liquids then transferring the saturated liquid into a pressurised liquid to nucleate microbubbles, which is very expensive.