Method for making biofuels more efficiently Monday, 25 January 2016

Engineers at the University of Melbourne have come up with a more efficient way of creating renewable fuels such as biodiesel from microalgae.

Head of the University's Chemical Engineering Department Professor Sandra Kentish said carbon dioxide is well known to speed up the growth of microalgae, however, it has to be free of contamination or the algae could die. Supplying purified carbon dioxide by extracting it from flue gases can work, but it is expensive and takes a lot of energy.

“In this work, we have found a way to purify the carbon dioxide and to supply it to the microalgae for a much more moderate cost and using a lot less energy,” Kentish said.

Their 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 membranes are like very long drinking straws, which can be immersed into the microalgae beds.

The CO2 moves directly from the liquid into the microalgae culture by permeating through the fibre walls.

The research is published in the journal, Energy and Environmental Science.

Dr Greg Martin  leads the Algal Processing Group, the team developing efficient downstream processing technologies for the conversion of microalgal biomass into different bioproducts.

“Aside from being a cheaper approach, our research has shown that the microalgae grow faster than in other work done to date,” Martin said.

He added that other products such as chemicals, proteins and nutraceuticals could also be produced using the same approach.  

The team is now undertaking further experiments to find the optimum liquid composition.

 

Image: University of Melbourne