Tire waste can be transformed into a wide range of innovative products. For example, recycled tire rubber is used to create recreation surfaces and athletic tracks and tire derived aggregate is also being used for infiltration galleries that filter stormwater. More recently, recycled tire rubber is being used as tire-derived fuel, rubber mats for industrial and agricultural use, and eco-friendly footwear and fashion accessories.
At the 2024 California Tire Conference, attendees were given an update on U.S. Market Trends and USTMA Initiatives. With the theme of “driving towards a circular economy,” the USTMA stated that scrap tire markets are not keeping pace with annual generation. “In 2021, roughly 71 percent of annually generated scrap tires entered end use markets – down from its 2013 peak of 96 percent. Scrap tire generation continues to grow each year by roughly 7 percent and growing sustainable, circular markets for scrap is a priority.”
The uses for recycled tires continue to evolve and grow and as Amir Hafzalla, executive vice president and president of the South Region at Reworld explained, the tire recycling industry has seen significant evolution in recent years, driven by the dual focus on recycling tires into new products and utilizing them as alternative fuel sources.
“Reworld has been at the forefront of this transformation with its specialized product line, ReKiln, which blends and engineers tires into high-grade alternative fuels. This innovative approach has generated strong demand, contributing to the industry’s overall health and expansion,” Hafzalla said. “The industry’s commitment to innovation and sustainability positions it well for continued growth.”
However, market conditions vary across states, heavily influenced by landfill regulations. According to Hafzalla, in states that permit whole tire landfilling, tire recycling is significantly reduced, as generators of used tires often opt for the least expensive disposal option, lacking sustainability goals.
“Conversely, off-spec tires from new tire manufacturers, which often have strict sustainability goals, typically require destruction, preferably through thermal processes,” Hafzalla said.
Reworld has capitalized on advancements in shredding technology, which have significantly reduced the amount of machinery needed for processing while improving efficiency and product quality. These improvements have enabled the company to streamline operations and lower costs, making its tire recycling process more efficient and cost-effective.
“A current trend in the industry is the practice of baling tires and shipping them to India for processing,” Hafzalla said.
At material processing facilities (MPFs) Reworld is actively involved in tire recycling with two primary technologies:
Whole tire to cement kilns: Reworld processes whole tires and uses them as fuel in cement kilns.
Tire-derived fuel (TDF): The company shreds tires to create TDF, which is then used in cement kilns as an alternative fuel.
At these MPFs, Reworld employs advanced processes to produce TDF and transform scrap tires into high-grade alternative fuel products as a part of ReKiln. By transforming waste that cannot be traditionally recycled, ReKiln contributes to landfill avoidance goals, mitigates the release of harmful emissions like CO2, sulfur, and nitrogen oxide, and recovers valuable materials that standard recycling systems may miss.
“Reworld also deploys a thoughtful multi-step process to remove contaminates from the flue gas before discharging it into the atmosphere,” Hafzalla said. “These initiatives are integral to the commitment of Reworld to sustainability and its leadership in decarbonizing the tire and cement industries.”
An offshoot of recycling, the tire industry is seeing efforts made in retreading existing tires.
“Much like tire recycling, retreading focuses on minimizing the environmental impact of the tire. By replacing the worn-out tread with new tread and reusing the original casing, the retreading process extends the life of the tire prior to the point of disposal or recycling,” said Emily Ledbetter, brand manager at Michelin Retread Technologies. “In addition, retreading one truck tire saves about 15 gallons of oil, according to the Tire Retread and Repair Information Bureau. Through our two networks of retreaders, Michelin Retread Technologies (MRT) and Oliver, Michelin retreads more than three million tires each year.”
Ongoing Efforts
During May 2024, industry professionals at the Tire Recycling conference in Atlanta, where they were introduced to the newly formed Tire Recycling Foundation (TRF), a joint initiative of USTMA and the Tire Industry Association. The TRF brings together the whole breadth of the tire industry to identify and promote economically viable tire recycling solutions. According to the TRF, key efforts of the organization will be connecting with state regulators on the use of rubber-modified asphalt (RMA) on roadways and the benefits RMA provides in terms of cost-effectiveness, sustainability and useability.
As TRF explained, RMA “extends pavement lifespan, enhances skid resistance and ride quality, and reduces traffic noise. Importantly, RMA is already a circular product, with materials continuously recycled and remade into new products. With recent federal infrastructure stimulus, more opportunities exist to expand the use of RMA in the U.S. than ever before.”
TRF stressed that “expanding end-use markets for recycled tires is crucial to maximizing the environmental benefits of tire recycling. By diversifying the applications of recycled tire rubber, new opportunities can be created to reuse end-of-life tires for new and important uses. Additionally, there is potential to explore new markets such as sustainable construction materials, eco-friendly consumer products, and renewable energy applications.”
At the 2024 California Tire Conference, Olivier Brauen, Michelin Americas vice president of circularity business solutions development and transformation, discussed a “road map to sustainability – building a circular economy together” within the tire recycling industry.
In his keynote address, Brauen addressed the influx of rubber modified asphalt and that improving the roads in the U.S. is a critical part the circular life of tires. Improved roads will mean that less tires are being replaced due to damage. “RMA is infinitely recyclable, so it’s a very good fit between our dream of improving the infrastructure of the U.S. and making the environments better. With the USTMA, we are helping to drive that change. Also our expectation is that we would see an increase in the tire-derived fuel (TDF) market which makes up roughly one-third of the overall end-of-life tire beneficial use markets; the ground rubber markets make up another third and we’ve seen increases in mulch where new plants have been put in place in molded and extruded products like mats.”
With his hands-on knowledge of the tire recycling industry and its overall impacts, Hafzalla said that the tire recycling industry is expected to encounter both challenges and opportunities as it continues to evolve. “The export of scrap tires is likely to affect pricing and the availability of raw materials for processors,” Hafzalla said. “Additionally, the growing use of alternative fuels, especially in cement kilns, will drive demand for recycled tire materials, with cement kilns increasingly requiring larger volumes in the future.”
Hafzalla said the industry can also anticipate further innovation in the incorporation of crumb rubber into new products, such as tires and bumpers, expanding its applications and market potential.
