Giving new life to end-of-life tyres

Car tyres are a major environmental problem, and carbon black – a material used in their production – is one of the culprits. A fine carbon powder produced from the incomplete combustion of heavy petroleum products, carbon black is mainly used to reinforce tyres, making them more resistant against ultraviolet rays and prolonging their lifespan.

Every year, about 14 million tonnes of carbon black are produced worldwide, generating up to 40 million tonnes of CO2 emissions. Of the roughly 1 billion tyres driven to the end of their useful lives each year, only a fraction of them are recycled. Doing its part to propel the tyre industry into the circular economy era, the EU-funded BlackCycle project has now produced the world’s first sCB.During a workshop held in November 2021, the BlackCycle partners announced a major technological breakthrough. This entailed the production of sCBs for tyre applications on a conventional carbon black furnace reactor using oils derived from the pyrolysis of end-of-life tyres. “This novel production of a sustainable material from end-of-life tyres represents a truly circular process,” states a press release posted on the website of BlackCycle project partner AXELERA, France.

Almost all rubber compounds use carbon black as a filler. Tests showed that replacing a fossil fuel-based carbon black with a carbon black made from oil derived from the pyrolysis of end-of-life tyres would not change the properties of the rubber compound. Consequently, high levels of durability, conductivity, rolling resistance and other characteristics will be maintained even for the most demanding rubber applications.

“Hence, we can assume that sCBs are an easy drop-in solution without the need to adjust the formulations of the rubber compounds or process parameters for instance in mixing, molding, or curing,” the press release reports. “Because the carbon black content of elastomeric materials is relatively high with about 30 weight % on average, the technology applying pyrolysis oil as feedstock for CB production is a major leap towards a more sustainable rubber industry.”

Launched in May 2020, the BlackCycle (FOR THE CIRCULAR ECONOMY OF TYRE DOMAIN: RECYCLING END OF LIFE TYRES INTO SECONDARY RAW MATERIALS FOR TYRES AND OTHER PRODUCT APPLICATIONS) project aims to demonstrate the application of circular economy principles to end-of-life tyres in Europe. It will create, develop and optimise a full value chain from end-of-life tyre feedstock to secondary raw materials (SRMs), eliminating resource waste throughout the chain and focusing on environmental impact. Thanks to the project, one in every two end-of-life tyres are expected to be incorporated into this new circular value chain. These SRMs will be used to create new ranges of passenger car and truck tyres that will be sold globally.

For more information, please see:

BlackCycle project website