Australian researchers believe eucalyptus trees are a potential source for low carbon renewable jet and missile fuel.
Dr Carsten Kulheim from The Australian National University (ANU) said powering a modern jet aircraft with anything other than fossil fuels was difficult, due to the high energy required.
"Renewable ethanol and biodiesel might be okay for the family SUV, but they just don't have a high enough energy density to be used in the aviation industry," he said.
"Eucalyptus oils contains compounds called monoterpenes that can be converted into a very high energy fuel, and this high energy fuel can actually fly jets and even tactical missiles."
Certain monoterpenes commonly found in eucalyptus oils such as pinene and limonene, can be refined through a catalytic process, resulting in a fuel with energy densities suitable for jet fuel.
Turpentine from pine trees is another potential source of these monoterpenes, but pines grow more slowly than eucalypts.
Kulheim said the aviation sector globally produces about two per cent of all human-caused carbon dioxide emissions and renewable fuels that could power commercial aeroplanes were limited and expensive but a solution could be growing all around us.
"If we could plant 20 million hectares of eucalyptus species worldwide, which is currently the same amount that is planted for pulp and paper, we would be able to produce enough jet fuel for five per cent of the aviation industry," he said.
Kulheim's co-researcher David Kainer said jet fuel derived from eucalyptus oils would be close to carbon neutral.
"It has minimal ecological impact," Kainer said. "We can plant these trees on marginal lands that have low rainfall, and we can also plant them in agricultural systems that have salinity problems and help them defeat that problem."
He said eucalyptus plantations globally produce up to 200kg of oil per hectare per year, but by selecting the best genetic stock they could produce more than 500kg of oil per hectare.
ANU conducted the study in collaboration with Oak Ridge National Laboratory, University of Tennessee and University of Florida in the United States.
[ANU's David Kainer and Dr Carsten Kulheim. Image: Stuart Hay, ANU]
Energy will be a major topic of discussion at the Australian Engineering Conference 2016 in Brisbane on November 23-25.