Metro
Solid Waste Department
600 NE Grand Ave.
Portland, OR 97232-2736
(503) 797-1650
Fax (503) 797-1795
August 1994
Recovery of tires from the Metro area remained high in 1993, market capacity and demand dropped with the loss of a major processor and a major end user.
Recovery of waste tires has been increasing since 1987 when the state Department of Environmental Quality's (DEQ) Waste Tire Program was established. Through a comprehensive program for permitting businesses collecting, storing or transporting tires, nearly all waste tires generated in Oregon in 1993 were recovered.
Most recovered tires that are in good shape are recapped (retreaded). Most of the remaining waste tires recovered from the Metro area flow to Waste Recovery Partners where they are processed into chips suitable for tire derived fuel (TDF), or secondary processing for use in pavement and molded products. Another Metro-area company, RMAC International, received a significant quantity of waste tires in 1993. RMAC, which went out of business in May 1994, converted waste tires into a liquid cutting stock that was blended with oil for use as an industrial or marine boiler fuel.
Graphic: Estimated Tons of Scrap Tires Recovered from Metro Area (1986-1993) [See source document]
Major Generators:
Recovery Rate: 16,124 tons = more than 95%[1]
Origin of Recovered Material: Oregon, Washington and Idaho
Secondary Uses: Approximately 75% of scrap tires recovered in the Metro area are processed for use as industrial boiler fuel. Other secondary applications include retread tires, rubberized asphalt, and a variety of molded rubber products.
Location of Secondary Users: Primarily Oregon and Washington
Market Value: The cost to dispose of a scrap tire at a local processor ranges from 65 cents for a passenger tire off the rim ($65/ton) to $15 for a semi-truck tire on the rim ($285/ton).[2]
<Factors Affecting Market Value:
Other Factors Affecting Recovery:
The table below shows the approximate breakdown of end uses for waste tires recovered in the Metro area.
| Recycling Process and Product | Estimated % of Recovered Material used in this Secondary Application |
|---|---|
| Retreading | 10%-15% |
| Using whole tires for playground equipment, erosion control or artificial marine reefs | Less than 1% |
| Chopping, shredding, or grinding used tires and reusing the rubber in secondary products | Less than 5%[3] |
| Mixing ground rubber from tires with asphalt to produce rubberized paving materials | Less than 5% |
| Chopping, shredding or grinding used tires for fuel (TDF) in industrial boilers | 75%-80% |
| Source: Metro Recycling Level Survey and processor interviews. | |
Tire processing involves separating the rubber from other materials contained in tires, such as steel and fiber, through mechanical shredding and grinding. Most secondary uses for waste tires are minimally to moderately sensitive to contaminants.
Scrap tire processing uses expensive, heavy duty machinery that typically is financed over many years. Given these factors, tire processing tends to require large-scale plants that minimize the unit costs of processing.
Because tires are banned from landfills, processing tipping fees are a function of processing costs and secondary product prices. Prices for TDF, the dominant product made from waste tires, are primarily a function of industrial fuel prices. While Waste Recovery is the only tire processor serving the Metro region, it competes to a limited degree with commercial stockpilers in Washington State for waste tires.
TDF competes with other industrial boiler fuels. The price of TDF is tied closely to the price of boiler-grade oil, natural gas, coal, and other recovered material fuels such as wood chips and densified paper and plastics.[4]
The approximate price spreads for some of these fuels are listed in the table below.[5]
| Fuel | $/Million BTU |
| Natural Gas | $2.40 to $3.20 |
| Wood (aka Hog Fuel) | $1.35 to $2.95 |
| Reprocessed Oil | $1.30 to $1.60 |
| Tire Derived Fuel | $1.05 to $1.95 |
The outlook for recovery of waste tires is uncertain. It depends upon processing capacity and secondary product demand, particularly for TDF. Prices of competing industrial fuels are expected to remain relatively steady for the next 6 to 12 months.
Natural gas supply and demand are increasing at approximately the same rates. Oil futures indicate continued low prices for this fuel. Demand for hog fuel appears to be slipping some due to prices, availability and particulate emission regulations, but demand for wood generally remains high relative to supply.
Demand for tire derived crumbed rubber for use in rubberized asphalt paving may increase in 1994 in response to the Intermodal Surface Transportation Act. However, implementation of this Act, which requires the use of tires and other recyclable materials in federally-funded paving projects, faces stiff opposition from the asphalt paving industry and state transportation departments.
Retreading may increase over the next several years as public agencies shift from new tires to retread tires in response to a 1993 contract the state Department of General Services established with Les Schwab tires. Under this contract, participating local, county and state governments can get retread tires at more than 250 eligible sites in the Pacific Northwest. This has improved the price of retreads and cut procurement time from several months to one hour.
[1] Based on 1993 Metro Recycling Level Survey and 1993 Metro Waste Composition Study.
[2] The National Recycling Coalition Measurement Standards and Reporting Guidelines list the average weights of passenger and semi-truck tires as 20 and 105 lbs., respectively.
[3] Products and applications in this category include playground fall bedding, sludge composting, running tracks, and a variety of molded rubber objects (e.g., rubber mats, dock bumpers, exhaust hangers, shoe soles).
[4] Wood chips that are burned in industrial boilers are called hog fuel or biofuel.
[5] Ranges are based on information from the Oregon Department of Energy and processor interviews in June 1994.
Last Updated: December 18, 1995