New cheap, better method to make biofuels

Scientists have discovered an inexpensive way to deliver carbon dioxide to micro-algae, which in turn can be harvested to make renewable fuels such as bio-diesel.
Carbon dioxide speeds up the growth of micro-algae. However, the carbon dioxide (CO2) has to be free of contamination or the algae die.
Researchers from the Melbourne School of Engineering discovered that this new method purifies the carbon dioxide that is in power station flue gases by absorbing it into a liquid.
This liquid is then pumped through hollow fibre membranes. These hollow fibre membranes are like very long drinking straws, which can be immersed into the micro-algae beds, researchers said.

Supplying purified carbon dioxide by extracting it from flue gases can work, but it is expensive and takes a lot of energy, they said.
"In this work, we have found a way to purify the carbon dioxide and to supply it to the micro-algae for a much more moderate cost and using a lot less energy," said Sandra Kentish from the University of Melbourne.

"The CO2 moves directly from the liquid into the micro-algae culture by permeating through the fibre walls. Aside from being a cheaper approach, our research has shown that the micro-algae grow faster than in other work done to date," said Greg Martin from the University of Melbourne.

Other products such as chemicals, proteins and nutraceuticals can also be produced using the same approach, researchers said.
The findings were published in the journal Energy and Environmental Science.