A Queensland-led team is working to turn the offcuts from Australia's $2 billion sugar industry into a clean gas that could be used to fuel vehicles.
Australia is the third largest sugar exporter and most of its 24 mills already use its sugar processing by-product, called bagasse, to generate electricity and steam for factory operations.
A joint project between Queensland University of Technology, Griffith University, Manildra Harwood Sugars, Sunshine Sugar and Utilitas Pty Ltd, will work to further improve the industry's self-sufficiency by attempting to turn sugarcane trash into biogas.
The project is the first of its kind in Australia and would see sugarcane offcuts such as leaves and twigs, usually burnt off or left to degrade in the fields, pre-treated, "digested", and again treated to withdraw any carbon dioxide.
The end product would be a methane-rich clean biogas, that could be upgraded to biomethane to fuel farm transport, with the solid waste becoming a fertiliser.
Biogas is a flexible product that contributes about 2 per cent of total renewable electricity capacity in Australia.
Utilitas CEO Fiona Waterhouse said biogas was largely used overseas in heat and electricity at cogeneration plants, however it was not as widely harnessed here in Australia.
"The reason biogas hasn't been deployed in Australia as much as overseas is because our energy has been so cheap for so long, we have coal to make steam, there are industrial heating processes that need heat but often they are large scale and driven by coal," she said.
"What is happening now is that level of variability is driving industry to say, 'Let's rethink this'."
Ms Waterhouse said the project was still in the initial design processes, but if successful, could see sugar mills shift away from the use of conventional fossil fuels and into a more renewable, sustainable sector.
"We are pioneering in digesting sugarcane trash and pioneering in taking biogas and turning it into transport fuel," she said.
Griffith School of Engineering lecturer Prasad Kaparaju said biogas was produced from broken down organic waste and was odourless, carbon neutral and renewable.
"If you want to use it as a compressed biogas, you need to clean up all the contaminants, you have to remove the carbon dioxide, then you get 92-96 per cent methane, that methane will be compressed and then put into gas bottles and into cars, you can use it as vehicle fuel," he said.
"If you move away from fossil fuel use and use your own biogas as vehicle fuel for your own fleet, it is cheaper to use biogas."
Dr Kaparaju said the only drawback for biogas would be the cost of converting the vehicles to be biogas friendly, which could be $6000 for each vehicle.
"That is the main drawback in the biogas, not all are interested to make a vehicle fuel because of the associated costs," he said.
Dr Kaparaju said the idea of waste efficiency could be applied to a number of different areas down the track.
"In the future, we are going to go into that circular bioeconomy where we try to use the waste efficiently to extract biofuels, chemicals, biocomposites," he said.
"Where nothing is going to landfill, that is the ultimate aim. It would be too expensive to send materials to landfill, you need to recover as much as you can.
"The waste management companies should come together and have a centralised system, central biogas plant and collect household waste separately and use the biogas from there to use in vehicle fuels picking up the waste."
Ms Waterhouse said the Arena project was a "stepping stone" towards better harnessing household waste.
"The pre-treatment and fuel processes (in this sugar mill project) could be applied to taking food organics and green organics out of the municipal waste and treating them the same way in the future," she said.
"This is a stepping stone in that direction, this has to happen for that happen, that is the end game."
