E4S: Top 10 Sustainability Projects - March/April

Following the announcement of winners in the annual Elastomers for Sustainability Awards (see ERJ Jan/Feb issue), the E4S programme continues into 2026 with a new Top 10 ranking of materials science-based sustainability project.

The programme will culminate in the announcement of a new set of E4S Awards winners, with the winning projects – those contributing most to enhancing the environmental profile of the tire & rubber sector – to be announced in early 2027.

As before, the top E4S rankings will be guided by an independent panel of experts, using established criteria for assessing the level of innovation, progress with commercialisation and potential significance going forward.

The latest ranking is headed up by new project entries as well as previous entries, which have been updated with a significant level of new information. Supporting information is provided below, with further details about these and other leading E4S projects available on ERJ Online.

NEW TOP 10 

Cabot Corp.

Project: Cabot’s Regenerated Reinforcing Carbon

Main technologies involved

Circular reinforcing carbon material produced with reclaimed carbon (also known as recovered carbon black) from pyrolysis of end-of-life tire (ELTs) and upgraded through Cabot’s regenerated carbon technology. Powered by Cabot’s Evolve Sustainable Solutions platform, the new CGX-1000 regenerated  reinforcing carbon, delivers ASTM N300-level performance in rubber, requiring little to no formulation adjustments. 

Main goal or objective: Cabot’s regenerated carbon technology development aims to introduce a new-to-world material, breakthrough circular materials that simultaneously  advance sustainability, performance, and scalability: optimising both the circular content and product carbon  footprint of reinforcing carbon materials, while maintaining the high level of in?rubber performance expected from ASTM N300?series carbon blacks. 

Technical challenges addressed: The use of reclaimed carbon from tire pyrolysis has historically been limited to modest loadings – typically <10% – in the replacement of mostly low structure, semi-reinforcing carbon blacks in tire applications due to significant performance drawbacks. Cabot has developed a circular reinforcing carbon product that incorporates 30% reclaimed carbon from ELT pyrolysis, enabling reclaimed carbon use in more demanding tire carcass applications that traditionally require higher surface area, higher structure N300-series carbon blacks.*

Commercial status of the technology or product: CGX-1000 regenerated reinforcing carbon is in the development phase and is not yet offered commercially, though samples are available for customer trials up to MT-scale.  Production at Cabot’s pilot facility in Pampa, Texas has demonstrated the ability to manufacture the material consistently at semi-commercial scale.

Contribution to sustainability: This product advances sustainability by enabling greater use of circular materials in tires, both by increasing the fraction of reclaimed carbon in tire formulations and broadening the tire components where reclaimed carbon-based materials can effectively be used. The use of reclaimed carbon can reduce the product carbon footprint; therefore, Cabot’s regenerated carbon technology can potentially reduce the carbon emissions relative to an ASTM N300 series carbon black. Cabot’s regenerated carbon technology provides a valuable outlet for reclaimed carbon, which supports the development of a more circular tire economy and contributes to a lower carbon future.

Future development goals: We are actively exploring opportunities to further increase the proportion of reclaimed carbon incorporated into future grades while maintaining the high performance expected of reinforcing carbons. Ongoing development efforts include evaluating higher reclaimed carbon loadings, advanced upgrading methods, and the potential integration of alternative feedstocks to further expand sustainable content in carbon black.*

Further comments: The regenerated carbon technology also provides modestly lower hysteresis (e.g., ~15% lower tan delta), which can improve the tire rolling resistance coefficient especially if applied in multiple components of the tire requiring N300 series carbon blacks. Reduced hysteresis enhances overall fuel efficiency, enabling additional sustainability benefits through improved tire performance.*

*More details on ERJ Online - E4S

Monolith Materials Inc. and Goodyear Tire and Rubber Co.

Project: Development of carbon black from plasma pyrolysis of hydrocarbons with equivalent performance to furnace carbon blacks for tire applications

Main goal or objective: To develop a carbon black produced from methane or other hydrocarbon plasma pyrolysis that would have equivalent performance to furnace carbon black across multiple applications within the tire, including a variety of rubber systems. 

Technical challenges addressed: Fine tuning of the carbon black colloidal properties and designing features in such a way to allow for comparable performance across different rubber systems and filler loadings was a technical challenge addressed by the project team. Each rubber system or compound application can result in a different expected response from the carbon black. Furnace carbon black, in this case, N660, behaves in a known way in each of the common systems where this grade of carbon black is used, butyl rubber or in a diene like natural rubber or SBR. Making a carbon black produced from a plasma pyrolysis process behave the same way in both rubber matrices was a significant accomplishment, enabled by intentional design of colloidal properties and appropriate formulation adjustments to achieve drop-in performance. To our knowledge, this is the first ever plasma pyrolysis carbon black development to allow for drop-in performance compared to a furnace black in a diene.

Commercial status: Commercially available at scale. Thousands of tons have been sold into applications.

Contribution to sustainability: The carbon black produced from plasma pyrolysis has a significantly lower carbon footprint than furnace carbon black, thereby allowing for a reduction in the carbon footprint for the end-use applications, such as tires. This lower carbon footprint comes from the use of low emission electricity and the fact that there is no combustion taking place during the production of the carbon black, unlike in the furnace black process.

Scope for further enhancements: Development of additional carbon black grades and further technology expansion to provide larger volumes and displace more emissions of CO2. Monolith has the ability to also utilize renewable, recycled or bio-based hydrocarbon feedstocks to further the already impressive environmental benefit that is afforded by Monolith's technology platform.

Extra comments: Monolith’s plasma technology offers a way to achieve the same performance as the furnace process while reducing the carbon footprint significantly – a real accomplishment as, today, the materials which allow for a lower carbon footprint cannot be scaled or do not offer equivalent performance to those that are in use today. Additionally, Monolith’s proprietary process delivers a yield of 95% - utilising almost 100% of the hydrocarbon molecule, whereas conventional furnace black processes, which typically achieve 55–65% yield.*

*More details on ERJ Online - E4S

Nokian Tyres with Reselo

Project

Betula concept tire that features “performance enhancing” rubber materials made from birch bark.

Main goal or objective: First tire to include the renewable material, produced by Swedish company Reselo using the residue of the global pulp, paper and plywood industry.

Technical challenges addressed: The material is included in the tread compound of the concept tire, bringing the amount of renewable and recycled material content to 93% of all materials used on the tread. The new material is seen primarily as a performance-enhancing addition.

Commercial status: The concept tire, that has the tread design of the Hakkapeliitta R5 non-studded winter tire, has been tested in the Nokian Tyres test centres in Ivalo, Finnish Lapland as well as in Nokia, Finland with promising results.

Contribution to sustainability: The new concept tire is part of Nokian’s sustainability strategy to achieve a 50% sustainable content in its tires by 2030. Confirmed its applicability and highlights the material’s potential for commercial use in the future. In 2024 the company launched the ‘Green Step Ligna’ containing a renewable lignin-based alternative for traditional carbon black. The company is currently commercially producing Seasonproof 2 all-season tires for the central European market with 38% sustainable content.

 Future development goals: In 2024, Nokian signed a development agreement with Reselo to further develop their renewable material for tire production. The development project will continue with Reselo after the launch of the concept tire.

Zeon Corp. and Yokohama Rubber Co.

Project: Highly efficient production of butadiene from sustainable ethanol

Main goal or objective; Develop and commercialise technology for production of bio-based polybutadiene rubber for tires by 2034

Technical challenges addressed: Produce butadiene and isoprene from bio-based feedstock and then develop prototype polybutadiene rubber and prototype tires

Commercial status: Early stage - target 'bench' facility for bio-process in 2026

Contribution to sustainability: Support transition to fossil-free tire rubber materials in-line with net-zero goals

Future development goals: Zeon and YRC are also working on a second project, involving the development of a “biotechnology” to directly produce butadiene and isoprene from plant-based materials

Addible

Project: OxyCycle – tire recycling technology*

Main goal or objective: To facilitate the reuse of materials in used tires - rubber, carbon black, textiles, steel, processing oils

Technical challenges addressed: Devulcanisation of sulphur crosslinks in rubber tyres in an oxidative process, allowing the solvation of rubber.

Commercial status: Advanced trials stage

Contribution to sustainability: We can recover all materials in a reusable form, achieving 98% mass recovery.

Future development goals: We have plans to develop a truly sustainable recycling plant using renewable energy, that generates high quality recycled rubber, carbon black, textiles, steel and processing oils.