Tire recycling in the United States is the disposal and reuse of waste tires.
Uses Several forms of waste disposal and reclamation have been put into place, using waste tires as both commodities (new tires) and a form of energy (fuel alternative).
According to the Rubber Manufacturers Association (RMA), as reported elsewhere, 52% of scrap tires are burned for fuel 12% are used in crumb rubber products 16% are used for civil engineering applications at least 14% are ground and dumped in landfills. Different agencies in the world are now recycling waste tires and other rubber goods into useful products instead of polluting the environment.Francis, R. (2016). Recycling of polymers: Methods, characterization and applications.
Whole tires can be used for a number of applications, including artificial reefs, breakwaters, erosion control, playground equipment, and highway crash barriers.Epps, J. A. (1994). Uses of recycled rubber tires in highways.
Waste tires are made of a material which can have another economic use. This means that tires which are no longer suitable for use on vehicles due to wear or damage, can be recycled to serve a new economic purpose (rubber asphalt and concrete, fuel alternatives, carbon sources, etc.).Dodds, J., W.F. Domenico, D.R. Evans, L.W. Fish, P.L. Lassahn and W.J. Toth. 1983. "Scrap tires: a resource and technology evaluation of tire pyrolysis and other selected alternate technologies". Technical Reports EGG-2241
There are many different uses for waste tires that are beneficial in helping reduce the amount of waste tires in stockpiles. Recycled tires are used in creating synthetic turf in sports arenas. Synthetic turf is made up of crumb rubber which is recycled rubber from automotive or truck scrap tires. Waste tires are also used to make rubber mulch which is used in gardens and playgrounds. Waste tires have also been known to be used in making track and field pavements, roads, and shooting targets. Recycled waste tires have several recreational uses. They are used for tire swings, flower pots, compost bins, retaining walls, and sandals in developing companies. They can also be used as fuel energy. Waste tires used as fuel are either shredded or whole, depending on the combustion device being used. Fuel produced from waste tires is known as tire-derived fuel (TDF).
There is a potential for using waste tire rubber to make activated-carbon adsorbents for air-quality control applications. Such an approach provides a recycling path for waste tires and the production of new adsorbents from a low-cost waste material.Lehmann, C. M. B., Rostam-Abadi, M., Rood, M. J., & Sun, J. (1998). "Reprocessing and reuse of waste tire rubber to solve air-quality related problems". Energy & Fuels, 12(6), 1095–1099. doi:10.1021/ef9801120 Also, recycled rubber from tires is used as a component of various products commonly known as "tire derived products". Such products include asphalt paving mixtures and as extenders in a variety of rubber products such as roofing materials, walk pads, carpet and flooring underlay and other products. More such products are being developed.Rutherford, D., & Recyclers, R. (1991). Patent US5115983 - Process for recycling vehicle tires.
Processing
To convert the waste tire into a valuable product, it must first be reduced in size and then recycled. The recycling process begins first by shredding tires into small manageable chips, which are then cooled to cryogenic temperatures, causing them to become brittle. They are then pulverized into a material that must be screened to remove large chunks of rubber or polymer. Finally, the remaining fibre and magnetic material are separated from the pulverized material using a magnetic separator and a vibrational separator. This form of recycling is environmentally friendly, and allows a valuable resource to be used again and again.Khais, Iosif. A. Reali, M. Reali, & I. Reznik. March 6th, 1997. Tire Recycling Process. United States Patent WO/1997/007893
Disposal In 2007, around 300 million tires were scrapped in the United States. In 2008 around one billion tires were being scrapped each year with an estimated further four billion already in stockpiles and landfills. Global production in 2008 was about 1.5 billion new tires. The U.S. alone produced 291.8 million tyres in 2009 as estimated by the U.S. Rubber Manufacturers Association. In 2013, of tires were generated in the U.S. Newer figures (2015) talk about 450 million scrap tires generated annually in the U.S.
The United States disposes of 279 million waste tires each year, representing over 4 million tons of scrap waste.Takallou, M. B. (1991). BENEFITS OF RECYCLING WASTE TIRES IN RUBBER ASPHALT PAVING - transport research international documentation. Transportation Research Record. The polymeric materials that tires they are made of do not decompose easily. Even after heavy use and wear, only a few grams are abraded from each tire before they are deemed not serviceable. This means that almost all the material is discarded, and a valuable resource is left to become an environmental pollutant, if dumped.Adhikari, B., De, D., & Maiti, S. (2000). "Reclamation and recycling of waste rubber". Progress in Polymer Science, 25(7), 909–948
Environmental issues Waste tires are generally discarded after only a small amount of rubber is worn away. Even so, these tires are unfit for further use in the vehicles they were made for. At the same time they are also unwelcome in landfills and have been proven to be an environmental threat.
Tires take a great deal of valuable space in landfills. In addition, they have been known to bubble to the surface of land fills as they tend to trap methane gas. This bubbling can contaminate local water systems, as it can damage the landfill liners that are meant to control contaminants. The different stabilizers and flame retardants added to tires have also been known to kill advantageous bacteria in the soil. Originally, dumping in landfill was the primary form of disposal for scrap rubber (70% in 1977), but due to the decreasing availability of space, this process is no longer considered feasible.
Waste tires create health and environmental challenges. Accumulation of waste tires, which are non-biodegradable polymers due to the presence of fillers, steel cord, organic, and inorganic components, is a major environmental concern.
The dumping of tires in landfills has negative effects on the environment. Not only do they take up a great deal of space, but their process of decomposing has created a wide variety of issues that have made their dumping landfills unfeasible. In many regions, dumping is banned.
The process of bubbling of trapped methane gas has been linked to increased mosquito and other insect breeding (increase risk of disease spreading), contamination of both underground and above ground water systems, as well as chemically destroying many beneficial bacteria that grow in the soil within and surrounding a landfill.
Tires have been stockpiled for years both legally (landfills) and illegally. In the United States alone there are about two billion around the country, with an estimated 279 million to be added to this number in the next few years. The legal stockpiling of tires increases the risk of fires which can burn for months on end, creating further pollution in the air and ground, while the illegal dumping of tires in forests, water ways and empty lots have caused pollution which cannot be regulated.Jang, J.-W., T.S. Yoo, J. H Oh, & Wasaki, I. 1998. Resources, Conservation and Recycling, 22(s 1–2), 1–14
The most obvious hazard associated with the uncontrolled dumping and accumulation of large amounts of tires outdoors is the potential for large fires which are extremely detrimental to the environment. Once a large pile catches fire, it is very hard, if not impossible, to extinguish.Reschner, K. (2008, July). Scrap Tire Recycling.
In 1978, a toxic fire at Wade Dump, a rubber recycling facility in Chester, Pennsylvania, burned out of control for several days and resulted in 43 injured firefighters and criminal charges for the owner of the site. First responders to the fire suffered long-term health consequences and higher than normal cancer rates.
Canada In 2010 the Newfoundland and Labrador government proposed that all waste tires in the province be shipped to Corner Brook to be burned and used as fuel. This was quickly delayed and further denied. A stockpile of 1.9 million waste tires in 2010 was a major environmental headache for the government. Environment Minister Ross Wiseman said the Multi-Materials Stewardship Board (MMSB), a provincial agency that promotes recycling, reached agreements with Holcim (Canada) Inc. and Lafarge Canada Inc. They agreed to ship tires to Quebec where they will be burned for energy.
Fees In most of the United States, a fee is included in every new tire that is sold. Fees can be collected by states, importers, and sellers, the latter being the most common case. These fees are collected to help support tire-recycling programs throughout the states. State tire-recycling programs are created to reduce the amount of scrap tires in stockpiles. The table below shows the tire fees in each state:
State Tire fee Reference Alabama $1 per tire Alaska $2.50 per tire Arizona 2% of retail sales price, up to $2 per tire Arkansas $2 per auto + truck tire, $5 per truck w/rim size greater than 19' California $1.75 per tire Colorado $1.50 per tire Connecticut none (repealed on July 1, 1997) Delaware $2 per tire Florida $1 per tire Georgia $1 per tire Hawaii $1 per tire Idaho none Illinois $2.50 per tire Indiana $0.25 per tire, trailer tires exempt Iowa $1 per tire Kansas $0.25 per tire Kentucky $1 per tire Louisiana $2 per tire (auto/light truck), $5 per tire (medium truck), $10 per tire (off-road) Maine $1 per tire Maryland $0.80 per tire Massachusetts none Michigan $1.50 per tire Minnesota none Mississippi $1 per tire (rim size less than 24'), $2 per tire (rim size greater than 24') Missouri $0.50 per tire Montana none Nebraska $1 per tire Nevada $1 per tire New Hampshire none New Jersey $1.50 per tire New Mexico $1.50 per tire New York $2.50 per tire North Carolina 2% of cost of tire (rim size = 19.5' or less), 1% of cost of tire (rim size more than 19.5') North Dakota $2 per tire Ohio $1 per tire Oklahoma $1 per tire (rim size 17.5' or less), $2.50 per tire (rim size is greater than 17.5' & less than or equal to 19.5'), $3.50 per tire (rim size greater than 19.5') Oregon none Pennsylvania $1 per tire Rhode Island $0.50 per tire South Carolina $2 per tire South Dakota $2 per tire Tennessee $1 per tire Texas none Utah $1 per tire (rim size 14' or less), $1.50 per tire (single-bead: rim size is between 14' and 19.5'), $2 per tire (dual-bead: rim size of 19.5'), $2 per tire (single/dual-bead: rim size is between 20' and 26') Vermont none, infeasible Virginia $0.50 per tire Washington $1 per tire West Virginia none Wisconsin $2 per tire Wyoming none
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