Researchers have developed new technology which produces carbon nanotubes and clean liquid fuel from used plastic - a smart solution for upcycling plastic and agricultural waste simultaneously.
Globally only about 20 per cent of waste plastics are recycled.
Boosting that figure remains a challenge as recycling plastic cleanly can be expensive and usually produces lower-value products, often making it financially unviable.
The new method from researchers at RMIT University can produce high-value products from plastic - carbon nanotubes and clean liquid fuel - while simultaneously upcycling agricultural and organic waste.
The team's two-step process, revealed in the Journal of Environmental Management, converts organic waste into a carbon-rich and high-value form of charcoal, then uses this as a catalyst to upcycle the plastic.
Lead researcher Associate Professor Kalpit Shah said upcycling two massive waste streams through one circular economy approach could deliver significant financial and environmental benefits.
"Our method is clean, cost-effective and readily scaleable," Shah said.
"It's a smart solution for transforming both used plastic and organic waste - whether tonnes of biomass from a farm or food waste and garden clippings from household green bins.
"We hope this technology could be used in future by local councils and municipal governments to help turn this waste into genuine revenue streams.
"With Australia banning export of waste plastic from next year, it's vital that we explore sustainable and cost-efficient alternatives beyond recycling."
Australia's national recycling target is for 70% of the country's plastic packaging to be recycled or composted by 2025, but a recent report found just 9.4% of plastic was recycled in 2017-2018.
The new method starts with converting agricultural or organic waste to biochar - a carbon-rich form of charcoal often used for improving soil health.
The biochar is used to eliminate toxic contaminants - such as Poly-cyclic Aromatic Hydrocarbons, known as PAHs - as the waste plastic is broken down into its components of gas and oil.
The process eliminates those contaminants and convert plastics into high-quality liquid fuel.
At the same time, the carbon in the plastic is converted into carbon nanotubes, which coat the biochar.
These nanotubes can be exfoliated for use by various industries.
The nano-enhanced biochar can also be used directly for environmental remediation and boosting agricultural soils.
