Turning mill waste into ethanol
THERE is a big pile of sugarcane waste at the Harwood Mill that will one day be litres of usable and valuable ethanol.
Ethanol Technologies senior research and development engineer Andrew Reeves said it took the company seven years and it could now turn sugarcane and timber waste into ethanol.
"We're not just thinking about us, this has impact worldwide," Mr Reeves said.
"The Clarence Valley could be an ethanol producing centre.
"We can produce litres of ethanol from minimal waste."
Mr Reeves said from lab calculations, they could get 400 litres of ethanol from a tonne of plant waste.
"Ethanol has many uses, but our goal has been to produce it for farmers to displace diesel with," he said.
"It is not well known, but using Ethtech technology, diesel can be blended with ethanol for use in diesel engines like tractors, cane hauling devices and other farm equipment.
"Anything that is biomass derived, or comes from a plant, can be turned to ethanol.
"That sugarcane waste has a lot of cellulose."
He said cellulose was like a microscopic chain of locked sugar that must be broken down into individual sugars for conversion to ethanol.
"Mixing it with acid and cooking it allows that cellulose to turn into glucose, or sugar."
Ethanol Technologies senior research chemist Tony Banks said the next stage was building a facility to turn the solution into ethanol.
He said although brewer's yeast could be used to turn their sugar solution into ethanol, they found a genetically modified micro-organism that would let them get 100% ethanol.
"Today is all about efficiency," Dr Banks said.
"You want to ferment 100% of your sugar.
"We don't want to leave any percentage of ethanol behind."
1. Get waste, dry it and break it down.
2. Mix it with acid. The waste turns into black play dough.
3. Cook it. These steps happen in 10 minutes
4. Filter it. You get a cake which can be used as fuel and then fertiliser.
5. Separate sugar from acid.
6. Recycle the acid
7. Ferment the sugar solution into ethanol