Scrap tire generation continues to outpace end market development. According to the Washington-based US Tire Manufacturers Association (USTMA) 2021 Scrap Tire Management Report, which was released on October 25, end markets consumed 71% of the scrap tires generated annually in 2021, up from 76% in 2019 when the USTMA published a similar report.
Over the past decade, scrap tire consumption has not kept pace with growing scrap tire production. In 2013, approximately 96% of waste tires generated were consumed by end markets, but in 2015 this figure fell to 88% and in 2017 this figure fell to 81%.
According to the USTMA, this latest collapse is due to a 13% increase in the production of used tires, while the markets that consume used tires only increased by 6%.
“Production is growing faster than the markets that are able to accept that, and what we need is more recycling markets that can accept the used tires that are generated,” says John Sheerin, director of end-of-life tire programs at USTMA.
Sheerin adds that he doesn’t think the generation of scrap tires will slow down in the short term, which will increase the need for more end markets for scrap tires.
“Over time, we are going to see more scrap tires being generated as the automotive market becomes electrified and as we continue to put more and more vehicles on the road and drive them further each year, we so let’s expect the generational trend to continue,” he says.
However, the USTMA reports that it sees growth opportunities for scrap tire end-use markets.
“On the recycling side, we have seen some very nice increases in the shredded rubber market [in 2021]Sheerin says. “We expect these to continue from what I hear in the market. The rubber modified asphalt market is seeing very solid growth, and it will continue into 2023 hopefully until ‘ in 2024. The mulch market has witnessed a huge increase in 2021. So these crushed rubber markets are expected to trend higher, and we need them to rise at a faster rate so that we can bring back our rate of beneficial use toward our goal of having 100% of scrap tires destined for sustainable and circular U.S. markets.
USTMA says it also sees the following near-term opportunities, including:
- Infrastructure Opportunities: With the passing of the bipartisan Infrastructure Act, USTMA aims to develop scrap tire markets that offer a sustainable infrastructure solution. USTMA says it has worked with congressional leaders to identify provisions in the bipartisan Infrastructure Act that support the recycling of scrap tires and the use of scrap tires in rubber modified asphalt and tire-derived aggregates in civil engineering projects. USTMA says it has also identified six specific policy proposals, ranging from tax incentives to research dollars and supply commitments, that support the implementation of scrap tire infrastructure technologies.
- Scrap Tire Management Programs: The USTMA says it is important for states to provide robust scrap tire management programs that generate revenue streams to fund research that develops and evaluates existing and emerging markets and addresses the reduction of worn tires.
- Scrap Tire Partnerships: USTMA has worked with stakeholders to encourage the growth of circular and sustainable scrap tire markets. In 2021, USTMA collaborated with The Ray, a philanthropic organization dedicated to the discovery and implementation of sustainable transportation technologies, and researchers from the University of Missouri-Columbia to produce a report on the state knowledge of rubber modified asphalt. The USTMA plans to publish similar research on tire-derived aggregates in partnership with the Tire and Rubber Association of Canada, Liberty Tire Recycling, First State Tire Recycling and the University of Wisconsin. The USTMA says it is also planning a scrap tire conference in 2024 to expand collaborative networks and partnerships.
End-Use Market Outlook
For many years, tire derived fuel (TDF) has been the largest end market for scrap tires. According to the 2021 USTMA Scrap Tire Management Report, TDF was the largest end market from 2013 to 2019. The USTMA reports that cement kilns, pulp and paper mills, electric boilers and industrial applications and electric arc furnaces are some of the main areas that have used TDF.
However, used tire consumption has declined in the TDF end market over the past decade. The consumption of used tires has decreased by 15% in this end market between 2019 and 2021, according to the USTMA.
Sheerin says some TDF users, such as electric boilers, are switching from TDF to natural gas. “There are fewer opportunities to use tire-derived fuel in the power and utility sector.”
He says the use of TDF by cement kilns and pulp and paper mills remained stable between 2019 and 2021.
In 2021, ground rubber has become the largest scrap tire end market. According to the Scrap Tire Management Report 2021, the crushed rubber market grew by 29% in 2021 compared to 2019, and the market consumed about 28% of all scrap tires.
In the crushed rubber end market, the use of scrap tires for molded and extruded products, such as carpets and rubber flooring, increased usage by 25% in 2021 compared to 2019, consuming 485 000 tons of used tires.
Rubber mulch increased its use by 54% in 2021 compared to 2019, consuming 391,000 tons of scrap tires. The USTMA believes that home improvement activities during COVID-19 related shutdowns have helped increase usage in this area.
“There’s been a boom in home improvement projects, and one type of home improvement project is to build a new play area for your kids or put mulch around the house,” Sheerin says. “So we’ve seen a very large increase in crushed rubber for mulch. We think that may not continue at the same rate that we’ve seen over the last couple of years, but this mulch market is growing very , very regular.
Rubber-modified asphalt consumed slightly fewer scrap tires in 2021 compared to 2019, consuming 141,000 tonnes of scrap tires that year. In addition, fine crushed rubber consumed 79,000 tons of waste tires in 2021.
The USTMA says several other end markets reported an increase in scrap tire consumption in its latest report. In 2021, civil engineering applications consumed around 6% of all scrap tires, mainly for tire-derived aggregates.
According to Sarah Amick, Senior Vice President of EHS&S and Senior Counsel at USTMA, the organization is currently seeking opportunities for tire-derived aggregates as well as information on the economic and environmental performance of tire-derived aggregates. She says the USTMA plans to publish the results of its research on tire-derived aggregates in 2023.
Additionally, the USTMA reports that the amount of scrap tires stored illegally has fallen to approximately 50 million in the United States in 2021. The USTMA says it estimates that over one billion scrap tires have been stored illegally in 1990. There were approximately 56 million scrap tires stored in the United States in 2019.
“This substantial reduction of more than 95% is the result of decades of progress in the development of the scrap tire recycling industry and the rehabilitation of storage sites,” the USTMA states of this decrease.
According to the USTMA, Texas inventory accounts for nearly 24% of total scrap tire inventory. Additionally, the USTMA says approximately 11.5 million stockpiled scrap tires are spread across the country with four states—Washington, New Mexico, Virginia, and New Jersey—exceeding 1 million stockpiled scrap tires.
“We are very pleased that states have continued to reduce these stockpiles, standing up to people who stockpile illegally,” Sheerin said.