QUT Professor Richard Brown and PhD student Farhad Hossain tested the oil extracted from old tyres in a process developed by Green Distillation Technologies. 

The GDT process takes tyres and turns them into oil, carbon and steel, with the latter coming from the belting put into the rubber.

Brown said that when the oil was blended with diesel it was found to produce a fuel with reduced emissions but no loss of engine performance.

Farhad said the QUT engineering team, including process engineer Dr Tom Rainey and air quality expert Professor Zoran Ristovski, performed rigorous tests on the oil.

“We tested the oil that GDT produces from both recycled natural and synthetic rubber tyres in 10% and 20% diesel blends,” he said.

“We tested the tyre oil blends in a turbocharged, common rail, direct injection six-cylinder engine in the Biofuel Engine Research Facility at QUT.

“The engine is typical of engine types used in the transport industry.

“Our experiments were performed with a constant speed and four different engine loads of 25%, 50%, 75% and 100% of full load.

“We found a 30% reduction in nitrogen oxide, which contributes to petrochemical smog, and lower particle mass, which means fewer problems for emission treatment systems.”

GDT chief operating officer Trevor Bayley said the oil could also be used as a heating fuel or further refined into automotive or aviation jet fuel.

“The process recycles end of life tyres into oil, carbon and steel, leaving nothing wasted and even uses some of the recovered oil as the heat source,” Bayley said.

“Carbon is the most common recovered ingredient and the steel rim and framework is third most common ingredient, while the oil is the most valuable.

“The potential of this source of biofuel feedstock is immense and it is more sustainable than other bio-oils from plants such as corn or algae.”

A recycled 10kg car tyre yields four litres of oil, 1.5kg of steel and 4kg of carbon.

Truck tyres – of the on the road variety – weigh about 70kg and provide 28l of oil, 11kg of steel and 28kg of carbon.

GDT plans to have the first fully operational commercial plant delivering 8 million litres of oil a year by mid-2017.

After that it wants to have a mining tyre processing plant in either Queensland or Western Australia.