Mitsubishi Chemical Group is launching studies to chemically recycle end-of-life tyres (ELTs) using coke ovens at its Kagawa Plant in Japan.

The company aims to start marketing sustainable carbon black made from recycled ELTs by March 2026.

Mitsubishi Chemical is leveraging its supply chain to feed crushed ELTs into its coke ovens and produce carbon black from the tar. This is believed to be the world’s first attempt to produce sustainable carbon black from ELTs using coke ovens.

The sustainable carbon black produced has the same performance as conventional carbon black, making it suitable for use in new tyres. This contributes to the closed-loop recycling of tyres.   

In July 2024, Mitsubishi Chemical began demonstration experiments to test the process. The company aims to sell sustainable carbon black at an annual rate of several thousand tons in fiscal year 2025 and tens of thousands of tons in fiscal year 2030.

By establishing chemical recycling technology for ELTs, Mitsubishi Chemical seeks to contribute to a circular economy in the automobile and tyre industries.

Kraton Corporation, a leading global producer of speciality polymers and high-value biobased products derived from by-products of pine wood pulping, has received an International Sustainability and Carbon Certification (ISCC) PLUS certification for its manufacturing facility in Niort, France.

Kraton can now supply 100 percent ISCC PLUS-certified AMS and AMS Phenolics resins using a mass balance attribution approach thanks to the certification. Kraton's dedication to promoting the biobased and circular economy is further demonstrated by the Niort facility's accreditation. Kraton is committed to lowering carbon emissions and accelerating the shift to a more sustainable future by empowering clients to include more environmentally friendly products into their supply chains.

An independent multi-stakeholder project, the International Sustainability and Carbon Certification (ISCC) is a leading certification method that guarantees accurate mass-balancing bookkeeping and reporting of renewable and recycled materials across the supply chain.

Lana Culbert, Kraton Pine Chemicals VP of Marketing, said, “Our SYLVARES™ and SYLVATRAXX™ brands feature a range of high-performance AMS and AMS Phenolics resins used in speciality adhesives and tyre applications. Our ISCC PLUS journey began in 2021 with the certification of our Sandarne, Sweden facility. Earning this certification for our Niort plant marks a significant milestone, further expanding our portfolio of sustainable solutions.”

Sumitomo Rubber Industries, Ltd. has said that it has clarified the process of rubber breakdown, a crucial element that affects tyre longevity, through joint research with Professor Gert Heinrich at Dresden University of Technology (Saxony State, Germany).

In a special session called ‘Combining Physics, Chemistry & Engineering of Rubber: A Symposium in Honor of Charles Goodyear Medalist Gert Heinrich’, which was held in honour of the Professor's medal-winning achievement, the findings were presented in an invited talk at the American Chemical Society, Rubber division, ACS 2025 Spring Technical Meeting held in Orlando, Florida, US, on 6 and 7 March. Professor Heinrich is a member of the Leibniz Institute of Polymer Research Dresden, which took part in the collaborative effort.

Tyre durability is determined by cracking processes, which result in the development of cracks and rips in a rubber substance. The endurance of rubber was previously mostly assessed using tearing tests, but there were still numerous unanswered concerns regarding the microscale structural alterations at the crack tip. This effort identified a factor that determines the start and propagation of cracks in rubber by analysing the force applied to a fracture tip using a simulation approach. In rubber, a crack tip undergoes dilatation deformation to create voids, or microvoids within the item. The fracture gets worse as the voids expand and come together. It was also discovered that the tension focused on the fracture tip is lessened when voids emerge.

The German Rubber Industry Association (Wdk) is advocating for a thorough and legally enforceable regulation of the end-of-waste status for Germany and the whole of Europe. The association is pusing for the circular economy to be strengthened for tyres.

Valuable secondary raw materials are still legally regarded as waste since there are no consistent standards for the end-of-waste status, according to Stephan Rau, Technical Director of the WDW. This restricts the market integration of sustainable recycled materials, impedes investments and creates legal uncertainties. “We call for a comprehensive and binding end-of-waste regulation for Germany and the whole of Europe to strengthen the recycling sector, facilitate investment in modern technologies, and sustainably reduce the CO₂ footprint of the rubber and tire industry,” he said.

In order to adhere to the prescribed waste hierarchy and stop illicit exports, Rau also emphasised that lawmakers must quantitatively and openly document waste tyre flows. He added that waste tyres should only be gathered by approved disposal companies and pre-sorted based on their intended use.

On the important role of mechanically recycled tyre granules and powder, Rau said, "This is an important secondary raw material that is already used in a variety of durable and safe products. A clearly defined end to its waste status must be made more economically viable. To ensure the market success of tyre granules, a risk-based approach to assessing chemical ingredients is essential. Binding limit values ​​must be assessed using a migration analysis, i.e. based on their bioavailability. Second, the use of tyre granule products must become mandatory in the construction industry and infrastructure projects. The goal is clear: Recycling must be economically viable."

Kuraray, a global speciality chemicals company and one of the largest suppliers of industrial polymers and synthetic microfibres, has received ISCC PLUS certification for its thermoplastic elastomers SEPTON and HYBRAR as well as Liquid Rubber produced at the Company’s Kashima Plant at Ibaraki Prefecture.

ISCC PLUS makes sure that certified products, such biomass and recycled raw materials, are appropriately handled throughout their supply chains, including the manufacturing process, by applying the mass-balance technique.

In the five years preceding up to its centenary in 2026, Kuraray is carrying out its medium-term management strategy, PASSION 2026. In order to achieve the long-term Kuraray Vision 2026 of being a speciality chemical company that grows sustainably by integrating new foundational platforms into its own technologies and contributing to customers, society and the planet, the company will keep growing its range of products that improve the natural and living environments.