Tyre Recycling: How Valuable Resources Can Be Kept in the Loop

Around 13.5 million tonnes of waste tyres are generated worldwide every year. This number is steadily increasing with the growing production and use of vehicles. While a significant portion of these tyres is already recycled or reused, there are also challenges such as current regulations. Nevertheless, tyre recycling remains an indispensable step towards reducing environmental pollution and an essential component of a circular economy.

According to the European Tyre & Rubber Manufacturers’ Association (ETRMA), around 92% of waste tyres in Europe are recycled or reused, while in the USA the recycling rate is about 81%. Tyre recycling offers a variety of ecological, economic, and social benefits:

• Reduction in Raw Material Consumption: Waste tyres contain valuable materials such as rubber, steel, and textile fibres that can be recovered and reused through recycling. This reduces the need for new raw materials and conserves natural resources.
• Reduction of Landfill Waste: Waste tyres that are not recycled often end up in landfills, where they can cause significant environmental problems. Recycling prevents these waste accumulations and the associated environmental risks.
• Reduction of CO₂ Emissions: The production of new tyres is energy-intensive and generates CO₂ Retreading and recycling of waste tyres consume less energy and thus contribute to reducing the CO₂ footprint.
• Circular Economy: Tyre recycling is a central component of the circular economy, which aims to minimise waste and maximise the reuse of materials. By recycling waste tyres, the lifecycle of materials is extended and the amount of waste is reduced.

• Cost Efficiency: Retreading tyres is generally cheaper than producing new tyres. This offers economic advantages for both consumers and businesses.
• Job Creation: The tyre recycling industry creates jobs in the collection, processing, and reuse sectors. This promotes economic development and provides employment opportunities.

• Technological Developments: Tyre recycling drives research and development of new technologies that improve the efficiency and effectiveness of recycling processes. Artificial intelligence, automated systems, and new material technologies are just a few examples of innovations emerging in this field.
• Sustainable Products: Recycled materials from waste tyres are used in a variety of products, from new tyres to flooring to sports surfaces and other applications. This promotes the development of sustainable products and markets.

Tyre recycling is an important process to reduce environmental impact and recover valuable resources. There are various methods of tyre recycling, which can be divided into mechanical, thermal, and chemical processes.

Mechanical recycling of waste tyres involves shredding and pulverisation. During shredding, waste tyres are mechanically broken down into several steps, resulting in different granulate sizes that can be further processed depending on the application. The granulate is often used in asphalt mixtures, flooring, or sports surfaces. Another step in mechanical recycling is pulverisation, where rubber powder is produced, which can be used to manufacture new rubber products or as an additive in various industries.

The advantage of mechanical recycling lies in the direct reuse of the material without chemical alteration, resulting in lower energy consumption and reduced environmental impact.

Chemical recycling of waste tyres primarily involves devulcanisation. Devulcanisation is a chemical process that breaks the sulphur bonds in vulcanised rubber, making the rubber soft and malleable again and allowing it to be used to produce new rubber products. Recycled rubber from devulcanisation can be used in tyre production, for rubber mats, seals, or other products.

The advantage of chemical recycling lies in the ability to alter the material at a molecular level, allowing the creation of new products with specific properties. Additionally, devulcanisation reduces the need for new raw materials and lowers environmental impact.

Thermal recycling includes processes such as pyrolysis and combustion in cement plants. In pyrolysis, waste tyres are heated in the absence of oxygen, breaking them down into their components: pyrolysis oil, pyrolysis gas, carbon black, and steel wire. Pyrolysis oil can serve as a substitute for fossil fuels, pyrolysis gas can be used as an energy source, carbon black can be used as a filler in tyre production or other applications, and steel wire can be recycled. Pyrolysis allows for the recovery of valuable raw materials and helps reduce the use of fossil fuels.

Another thermal process is combustion in cement plants, where waste tyres are used as a substitute fuel. The high calorific value of tyres contributes to the energy supply of the cement production process, while the mineral components are used as raw materials in the cement product. This process reduces the need for fossil fuels and efficiently utilises the energy properties of waste tyres.

These various methods of tyre recycling help conserve resources, reduce environmental burden, and return valuable materials to the production cycle.

Recycled materials from waste tyres find diverse applications, which are both ecologically and economically significant. Rubber granulate is used in asphalt mixtures to improve the flexibility and durability of road surfaces and is found in soundproofing panels to reduce noise pollution. On sports and playgrounds, it provides a shock-absorbing layer that minimises the risk of injury, while running tracks in sports facilities benefit from the elastic and durable properties. In industrial environments and gyms, robust, non-slip flooring made from recycled rubber is used. Moreover, recycled rubber is used in many everyday products such as floor mats, shoe soles, and seals.

Upcycling or creative reuse of waste tyres ranges from construction and decorative materials to playground equipment and garden furniture. Such innovative applications help reduce waste and raise awareness about recycling.

In retreading, the worn tread of a tyre is removed and replaced with a new rubber layer, significantly extending the tyre's lifespan. This sustainable method is particularly common in the commercial vehicle industry.

Artificial intelligence (AI) can provide significant advantages in various areas of tyre retreading, improving the efficiency and quality of processes. Here are some specific applications:

Integrating artificial intelligence into tyre retreading offers numerous opportunities to increase efficiency, reduce costs, and improve product quality. This not only contributes to the economic viability of retreading processes but also supports sustainability goals through more efficient use of resources and waste reduction.

Tyre recycling faces significant regulatory challenges that affect the efficiency and implementation of recycling processes. A central issue is the contradictory EU regulations, particularly regarding sustainable public procurement. The EU Taxonomy Regulation, which aims to promote environmentally sustainable economic activities, often excludes retreaded tyres due to their lack of inclusion in the tyre labelling regulation. This leads to retreaded tyres not being considered in many public tenders, even though they are comparable to new tyres in terms of environmental and safety properties.

Another problem is the lack of a tyre label for retreaded tyres, which would allow their integration into EU regulations. The European Retreading Association BIPAVER and the Alliance for the Future of Tyres (AZuR) have been advocating for years for the inclusion of retreaded truck and bus tyres (C3 tyres) in the tyre labelling regulation. Until this is achieved, the planning security for companies in the retreading industry remains low, hindering investments and developments.

The current regulatory situation not only burdens the economic viability of retreading companies but also contradicts the EU's climate goals. Retreaded tyres offer significant ecological advantages over new tyres, including a reduction in CO₂ emissions by over 60% and a saving of around two-thirds of the required raw materials, primarily rubber. These advantages could be better utilised through improved regulatory support and adaptation of existing regulations.

Overall, it is clear that clear and consistent regulations are necessary to fully exploit the potential of tyre recycling and to contribute to European environmental and climate goals.

There are numerous innovative projects and best practices in the field of tyre recycling that demonstrate how companies and research institutions are working together on sustainable solutions.

Covestro: Closing the Loop for the Automotive Industry

One example of the innovative use of recycled tyres is the joint project by Neste, Borealis, and Covestro. These companies are working together to close the loop for the automotive industry by processing waste tyres into new car parts. Covestro uses recycled raw materials from waste tyres to produce high-quality polymers used in the automotive industry.

Another example of sustainable innovations in tyre production comes from LANXESS. The company develops and produces rubber additives that help reduce the environmental impact of tyre manufacturing. These additives improve the properties of rubber and enable more efficient production. This not only extends the lifespan of tyres but also reduces energy consumption and CO₂ emissions during the production process. This project highlights the importance of chemical innovations for sustainability in the tyre industry.

These examples illustrate how significant progress in tyre recycling and sustainable tyre production can be achieved through cooperation and technological innovations. Such projects set benchmarks and show how ecological and economic goals can be harmonised.

Tyre recycling plays a crucial role in the future of our environment and economy. Given the billions of waste tyres generated worldwide each year, it is essential to develop efficient and sustainable methods for reusing and processing these waste products. By recycling tyres, significant amounts of resources can be saved, and environmental impact reduced.

Mechanical, thermal, and chemical recycling offer a variety of ways to recover valuable materials and use them in new products. Additionally, the use of artificial intelligence in tyre recycling opens new horizons. Automated inspection systems, optimised material usage, and predictive maintenance contribute to improving the efficiency and quality of recycling processes.

Regulatory challenges, however, require continuous efforts and adjustments. Better integration of retreaded tyres into EU regulations and the creation of clear and uniform criteria for public procurement are necessary to fully exploit the potential of tyre recycling.

Overall, tyre recycling is not only a key to reducing environmental pollution but also an important factor in promoting a sustainable circular economy. It helps conserve natural resources, reduces CO₂ emissions, and offers economic benefits by creating new business opportunities and jobs. Therefore, the importance of tyre recycling will continue to grow in the future, making a significant contribution to a more sustainable world.