by MAURA KELLER
We’ve known about the need for improved rubber recycling technologies for years, as millions of end-of-life tires are sent to landfills. The accumulation of discarded tires results in significant environmental hazards, including spontaneous combustion and chemical leakage.
While one key technology being used in tire recycling, namely pyrolysis, has resulted in efficient recycled rubber byproducts, there are additional environment and health risks with this technology. Luckily, technological advancements in rubber recycling is on the rise.
Ross Lakhdari, sustainability expert with PA Consulting said rubber recycling has undergone significant transformation, driven by heightened regulatory oversight such as landfill bans on end-of-life tires (ELTs) and extended producer responsibility programs, which place the burden of collection, recovery and recycling directly on producers.
“At the same time, leading manufacturers in the automotive, tire, flooring and construction industries are setting ambitious sustainability goals and increasingly integrating recycled rubber into their products to meet these targets,” Lakhdari said. “To meet the growing demand for high quality recycled rubber, the industry has expanded and modernized its collection and reprocessing infrastructure. This has shifted rubber recycling away from basic mechanical shredding and low-value uses like tire-derived fuel or generic crumb rubber, towards more advanced reprocessing and the creation of higher-value applications.”
“Simply put, the rubber industry produces a vast amount of waste, primarily due to tire manufacturing and consumption,” Lakhdari added.
In fact, nearly 70 percent of all rubber produced globally goes into the production of tires. Each year, approximately 280 million tires reach the end of their usable life worldwide, yet only a small proportion – about 30 million – are reused. This leaves roughly 250 million scrap tires that require effective recycling or disposal solutions. Advances in recycling technology are crucial not only for minimizing the industry’s environmental impact but also for driving the transition toward a circular economy, making recycled rubber an increasingly practical and attractive alternative to new materials.
As Lakhdari explained, rubber recycling, like many other material reprocessing technologies, has been transformed by significant advancements that enable more efficient and valuable resource recovery and open up new pathways for recycled feedstocks.
“Some of these advancements, while they are not a new concept, are reaching the scale to be a critical part of the end-of-life reprocessing for waste rubber,” Lakhdari said.
These include:
Advanced pyrolysis: A thermochemical process for producing high-value fuels and energy from waste materials. Carbon black can also be a by-product originating from the char of the pyrolysis process and can be used as an alternative to virgin carbon black.
Cryogenic grinding: Applies liquid nitrogen to waste rubber prior to grinding into small particles. The rubber, or “crumb,” particles that remain can be used as an input material for textiles, carpets, or coatings.
Devulcanization: Reverses the vulcanization (cross-linking) process in rubber, restoring elasticity and plasticity so it can be reused and even blended with virgin materials to go back directly into high value applications.
In April, University of North Carolina at Chapel Hill announced that a team of scientists at the University has developed a groundbreaking chemical recycling method that could offer “a cleaner, more sustainable solution to the growing global problem of tire waste.”
According to the University’s news release, “There’s a substantial amount of rubber accumulating in landfills,” said Dr. Aleksandr Zhukhovitskiy, lead author of the study and an assistant professor of chemistry at UNC-Chapel Hill. “These tires provide an environment for microorganisms to grow and potentially release toxic materials, and over time, they can generate microplastics and other pollutants we don’t yet fully understand.”
As the University explains, Zhukhovitskiy’s lab has been focused on what he calls “editing the skeletons” of plastic materials – changing the structure of polymers to make them easier to break down or reuse. In the case of tire rubber, the researchers used a gentle chemical process to insert nitrogen atoms into the material, creating a pathway for it to break apart into smaller, soluble pieces.
This study introduces a novel chemical method for breaking down rubber waste. The pioneering technique utilizes C–H amination and a polymer rearrangement strategy to transform discarded rubber into valuable precursors for epoxy resins, offering an innovative and sustainable alternative to traditional recycling methods.
“Our research represents a paradigm shift in how we approach the problem of rubber waste,” said Sydney Towell, a co-author of the study and Ph.D. candidate at UNC-Chapel Hill. “By harnessing the power of C–H amination and backbone rearrangement, this method provides a new pathway to transforming post-consumer rubber into high-value materials, reducing reliance on landfills and minimizing environmental harm.”
Even more recently, the Korea Advanced Institute of Science and Technology (KAIST), announced it succeeded in selectively converting waste tires into high-purity, high-value cyclic alkenes, which are chemical raw materials used for rubber or nylon fibers.
Specifically, the KAIST research team used two catalysts to develop a method to convert waste rubber into useful chemicals. The first catalyst helped break down rubber molecules by changing their bonding structure, and the second catalyst created cyclic compounds through a ring-closing reaction.
According to KAIST, “the produced cyclopentene can be recycled back into rubber, and cyclohexene can be used as a raw material for nylon fibers, making them industrially very valuable.”
The Recycled Rubber Coalition announced that Mitsubishi Chemical Group (MCG) has begun producing carbon black from recycled tires. MCG creates carbon black by crushing tires in its coke ovens, and the company reports that the recycled carbon black is comparable to new carbon black. MCG plans to bring its recycled carbon black to market in 2026.
Despite significant progress along every segment of the end-of-life value chain, from recovery to sorting to reprocessing, rubber recycling still faces several challenges. One of the biggest hurdles that Lakhdari pointed to is in the preservation of material properties. As he explained, “maintaining or restoring the mechanical strength, elasticity and overall quality of recycled rubber can be difficult, limiting its use in high-performance applications and ultimately leading to downcycled applications.”
Another hurdle facing the rubber recycling industry is in the supply chain complexity whereby collecting, transporting and handling bulky waste tires and rubber in a cost-effective manner requires efficient logistics systems, which are lacking in this industry.
In addition, Lakhdari said that, like many other waste feedstocks, recycled rubber often competes with lower-cost virgin materials, making it harder to achieve widespread adoption without regulatory or market incentives.
“And recycling methods, such as pyrolysis, can be energy-intensive, produce undesirable by-products, or require costly capital equipment to achieve higher purity and efficiency,” Lakhdari said.
Experts agree that the global rubber recycling industry has plenty of room to improve. Lakhdari said progress will likely be shaped by embracing cutting-edge technologies, automating more processes, and using digital tools to track materials and ensure consistent quality.
“Collaboration across manufacturers, recyclers and regulators will be key to setting common standards and finding, or creating, new markets for recycled rubber,” Lakhdari said. “As recycling capability advances, we can expect recycled rubber to show up in even more high-value products as recycling technologies scale and become more affordable.”
Published August 2025