Keep valuable raw materials in circulation, replace fossil resources in a climate-friendly way
Every year, over 500.000 tons of used tires are generated in Germany. These are collected and inspected by certified waste management companies. Tires that can no longer be repaired, re-treaded, or retreaded are sent for climate-friendly recycling – for example, chemical recycling.
In chemical recycling, the raw materials contained in tires are selectively broken down using thermochemical processes to keep them in circulation and to replace fossil raw materials in a climate-friendly way. A key process in this recycling method is pyrolysis, in which the tires are broken down into their material components under controlled conditions. The steel separated in this process is then sent for metallurgical recycling.
In modern, highly efficient pyrolysis plants, the previously shredded and granulated used tire rubber is thermochemically decomposed at 500 to 700 °C without oxygen. The heat breaks down the complex polymer structures of the tire rubber, allowing the components to be separately recycled. This process produces gas, pyrolysis oil, and a solid carbon residue, which is processed into recovered carbon black (rCB).
The pyrolysis gas produced in the process can be used for energy generation, making the pyrolysis process almost energy self-sufficient.
The condensable gas fraction is condensed as pyrolysis oil. This allows a large portion of the carbon to be recovered from the polymers of the tire compound. The oil is used in the chemical industry as a substitute for fossil carbon. It is used (along with fossil raw materials, on a mass-balance basis) in conventional C4 crackers to produce monomers.
Recovered Carbon Black is a process that recovers the industrial carbon black contained in used tires. It is ground to a very fine, homogeneous particle size and pelletized – serving as a climate-friendly substitute for fossil-based industrial carbon black, which, for example, accounts for up to 80 percent of CO₂ emissions in tire manufacturing.2 This saves money. Recovered Carbon Black is a valuable secondary raw material for the production of new tires and a variety of rubber-based products.
Chemical recycling through pyrolysis contributes to resource conservation by enabling the recovery of materials that would otherwise be either unusable or only partially recyclable. Pyrolysis transforms waste into valuable secondary raw materials. Natural and synthetic rubber, as well as fossil fillers from used tires, are transformed into new resources in an environmentally friendly way – an important step towards a functioning circular economy. Pyrolysis yields approximately 2,5 liters of oil and 3,5 kilograms of recovered carbon black from one tire.
Pyrolysis is undergoing continuous technological development. Modern plants aim to increase efficiency, minimize emissions, and further improve the quality of the recovered secondary raw materials. In combination with other recycling methods, chemical recycling contributes to the responsible, environmentally sound, and resource-efficient handling of tires.