Canberra, September 22 : Researchers at the CSIRO Sustainable Ecosystems in Canberra have determined that biofuels made from the stubble left over from harvesting wheat grains could replace around one fifth of the volume of petrol used in Australia.
According to a report in ABC News, Dr Michael Dunlop of CSIRO Sustainable Ecosystems said that based on 2001 figures, the 10 main grain crops of Australia produce about 65 million tonnes of stubble.
He said that much of this needs to be left in the ground to protect soil, retain soil carbon and reduce evaporation.
This would leave just under fifteen million tonnes of remaining stubble to be distributed in a way that is economically viable to collect.
"That would be equivalent to roughly 20 percent of the volume of the petrol that we use," said Dunlop.
The researchers analyzed figures for wheat, barley, canola, lupins, oats, sorghum, triticale, field peas and chickpeas in their study.
"Stubble is probably one of the more widely distributed feedstocks that is currently available," said Dunlop.
Dunlop said that it's important to consider the energy used to grow, harvest and processed a proposed biofuel feedstock.
Using waste stubble could help minimize extra energy used because the energy has already been put in to growing the grain, but energy will be required to process the stubble into biofuel, explained Dunlop.
According to Dunlop, the amount of stubble available will vary between 4 and 40 million tonnes depending on how much is produced, how much needs to be retained for soil health, as well as a range of economic and technical factors.
"Using waste stubble would avoid having to allocate precious food-producing land to produce biofuels," said Dunlop. "And using it would also avoid having to introduce exotic and potentially weedy species," he added.
"It's a resource that is there so we don't need to undertake any land use change in order to produce it," he said.
Dunlop also said that using stubble as a feedstock would not require massive additional infrastructure.
"The infrastructure required for harvesting, collecting and distributing it is all pretty similar to that used for grains," he said.
The researchers are also evaluating other possible biomass feedstocks such as forestry residues and mallee crops.