What’s Up with Tires?

January 6, 2014

Recently I participated in a Northeast Scrap Tire Market Development Workshop organized by the Rubber Manufacturers Association (RMA)^[1] to address market development opportunities for tires in the Northeast. The closing of the ReEnergy Sterling (Exeter) Tire-to-Energy Facility located in Sterling, Connecticut in October precipitated the meeting. Prior to its closing, approximately eight million scrap tires generated in the Northeast were sent to the facility each year. The meeting brought together private sector haulers, tire processors, and state representatives to discuss options for future market growth in the Northeast.

According to a 2009 RMA Scrap Tire Management Summary there were approximately 296 million scrap tires generated in the country in 2009. “Light Duty Tires,” including passenger tires, make up 87.33% of the discarded tires at 259 million tires scrapped; nearly 37 million commercial tires were scrapped.

According to the RMA study, scrap tires found their way into a variety of markets:

• 40.3% were used for tire‐derived fuel
• 26.2% were made into ground rubber
• 12.6% were land disposed
• 5.5% were used in civil engineering projects
• 7.2% went for reuse as scrap tires
• 8.2% wound up at various other destinations, including 2% as exports and 2.5% for reclamation projects

Tire-derived fuel (TDF) is the largest U.S. scrap tire market. Industrial facilities, including cement kilns, pulp and paper mills and electric utilities use TDF as supplemental fuel. Of the estimated 2,084,750 tons of scrap tires diverted to the TDF market, the majority went to fuel pulp and paper manufacturing (34%); cement kilns used 29%; electric utilities used 16%; industrial boilers 11%; and dedicated “tires to energy” facilities used 10%.

In 2009, the total amount of tire rubber consumed in ground rubber markets was about 1,625,000,000 pounds. Ground rubber or crumb rubber is a versatile tire derived material that is used in a range of products, from sport safety surfaces to asphalt modifications. The U.S. ground rubber markets in 2009 also provided a range of market opportunities for tires: molded/ extruded product manufacturing consumed 31% of the ground rubber; 24% went to sports surfacing; playgrounds/mulch/animal bedding consumed 20%; asphalt 11%; automotive uses consumed 7%; and, 7% of the ground rubber went for export.

Tire Derived Aggregate (TDA) is used as a construction material for civil engineering applications including lightweight fill, thermal insulation, vibration attenuation, septic system trenches and drainage layers. While currently not a large market for scrap tires, there is potential for growth in this area. TDA offers an advantage in many applications due to its lightweight qualities.

As of 2013, 25 states now use rubber modified asphalt (RMA). New technologies being explored include warm mix technology, terminal blends using rubber, and performance grade rubber modified asphalt. RMA presents a market growth opportunity in the Northeast and other parts of the country. It is increasingly cost competitive with conventional asphalt.

Tire management has certainly come a long way since the days of “tire mountains” containing thousands of scrap tires. According to the 2009 RMA study, stockpiles of tires continue to decline around the country from a high of an estimated billion tires in 1990 to 111.5 million in 2010.

Interestingly, while most tire haulers charge a handling fee to accept tires; most states are out of the tire fee business now or if fees are charged they do not go into a dedicated fund for tire management or tire market development. Not much is happening outside of California and a few other states in terms of active market development for scrap tires. Private sector leadership is providing a role in developing new applications and expanding existing market options for TDA and rubberized asphalt. However, an increasing void in market development is limiting expansion of tire-derived products into many market opportunities, including increasing public sector use of TDA for civil engineering projects, RMA on roadways, and even ground rubber products in parks and recreation applications.

An important topic discussed at the workshop is the need for greater communication between the various state Departments of Environment, Departments of Health, and Departments of Transportation to get everyone on the same page in terms of potential applications and uses of scrap tire products. Opportunities abound for uses of TDA in a range of civil engineering applications, but often Departments of Health and Departments of Transportation representatives are resistant to exploring new applications and approving the use of new products. Engaging municipal governments in the discussion is also in need of attention. All states and municipalities have roads, erosion issues, infrastructure issues, and a host of other opportunities for use of tire-derived products and applications.

In the Northeast, as with the rest of the country, a heavy reliance on TDF use in paper and pulp mills and similar facilities is a concern. Such facilities are on the decline and as with the closing of the Sterling Facility, this reliance is likely to continue to cause ripples in the demand equation for scrap tires. As pointed out by several of the workshop participants, a multiple-markets approach is needed to provide a long-term sustainable solution for handling tires.

Scrap tires are an inevitable part of our life and the waste we generate. It seems important for solid waste managers to take another look at tires and begin a dialogue about what needs to be done in terms of promoting and increasing market development for scrap tires and expanding the use of state and municipal applications of tire-derived products.

According to the Rubber Manufacturers Association, there are approximately seven gallons of oil in every tire. Five gallons are used to make the synthetic rubber comprising the tires and approximately two gallons of oil per tire goes for the energy required for the manufacturing process. This is a lot of a vital world resource being used--and wasted--if we fail to better manage scrap tires as a potential resource in a wide range of appropriate applications.

By Athena Lee Bradley