AN INNOVATIVE approach to ethanol production from woody residue has placed a small team from the Department of Primary Industries research facility at Wollongbar at the forefront of the biofuels movement.
The team's research, which is unusual in its biochemical approach to the process, has successfully converted eucalypt woodchips, sorghum straw and even grain-rich feedlot manure into sugar syrup and then into ethanol.
Competing technologies rely on chemistry alone to break down the woody pulp, which creates its own problems with acidic waste.
The Wollongbar team, led by Dr Tony Vancov, uses natural enzymes - not genetically modified - to do the specific job of cutting free the chains of glucose found within woody pulp - or as Dr Vancov calls it 'lignocellulosic biomass'. The resulting sugary water, or hydrolysate, is fermented to ethanol using baker's yeast.
The team has found that one tonne of eucalypt chips was converted into 456kg fermentable sugars, with a projected final ethanol yield of 280 litres/tonne, a result that has pleased Dr Vancov.
While fuel is the desired end product, there is more to be 'farmed' along the process path. Sorghum biomass yields reddish anticyanins which are rich in antioxidants, and might be used as a food colour.
By tweaking the enzyme process the team can create oligomeric saccharides that assist gut flora in humans.
In fact, the sugar itself may be more valuable than the fuel, says the team's post doc scientist Shane McIntosh, citing income streams from the nutriceutical industry as the most likely.
The next phase for the team is to upscale all they've learned in the lab to create a small commercial plant.
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