Research from Queensland finds blended diesel fuel reduces emissions, maintains power
New research from the Queensland University of Technology (QUT) has highlighted the potential of recycled tyres to form an emissions-reducing bio-oil.
According to the university’s mechanical engineers, the oil produced from a new tyre recycling technology process can be blended with diesel in small percentages to reduce the particle mass emissions from the engine without sacrificing performance.
The ongoing testing is being run by QUT mechanical engineer Professor Richard Brown and PhD student Bangladeshi-born Farhad Hossain along with local tyre recycling company Green Distillation Technologies (GDT).
GDT, which won bronze in the US International Edison Awards last year for its innovative way to dispose of old consumer and truck tyres, breaks the tyres down into oil, carbon and steel.
Using oil produced at the facility as a power source, GDT’s recycling process recovers 4kg of carbon, 1.5kg of steel and 4 litres of oil from a recycled 10kg car tyre.
A 70kg truck tyre on the other hand will yield 28 kg of carbon, 11 kg of steel and 28 litres of oil.
Utilising this oil offset for the trial, Hossain says saving tyres from landfill will benefit both the community but also the environment.
“There are 1.5 billion tonnes of tyres discarded globally each year,” he says. “Getting rid of old tyres in an environmentally-friendly way is a universal nightmare for authorities.
“Stockpiles of used tyres around the world are a health hazard, as demonstrated by the recent Broadmeadows fire in Victoria which was difficult to put out and generated huge amounts of toxic smoke and in tropical areas old tyres are a breeding ground for mosquitoes that carry the Zika virus, dengue fever and malaria.”
Trialling 10 and 20 per cent diesel blends, Hossain says the tests involved an engine “typical of engine types used in the transport industry.”
“We tested the tyre oil blends in a turbocharged, common rail, direct injection, six-cylinder engine at the Biofuel Engine Research Facility at QUT,” he says.
“Our experiments were performed with a constant speed and four different engine loads of 25, 50, 75 and 100 per cent of full load.
“We found a 30 per cent reduction in nitrogen oxide which contributes to photochemical smog, and lower particle mass which means fewer problems for emission treatment systems.
“We also found the performance of the oil blends were consistent through all of the blends and will continue this testing in subsequent research.”
The early indications from the QUT research could have a big impact on the future of tyre recycling, GDT COO Trevor Bayley says, as the company had previous thought the oil by-product was destined for heating or further refinement.
“We are delighted at the findings of the QUT research as it will help us promote the sustainable use for end-of-life tyres, as it has already been found by refinery Southern Oil that our oil from recycled tyres has been overlooked as a potential biofuel source, yet they say it is the most reliable and easiest to refine of all,” Bayley says.
“They have said that the future potential of this source of feedstock is immense, in fact preferable to other bio-oils from plants or algae, plus it will reduce Australia’s dependence on imported fuel and it is an excellent example of converting an environmental waste problem into a valuable raw material.”
GDT has been running since 2009, operating a pilot plant in New South Wales that handles 19,000 tonnes of car and truck tyres annually.