They are the bane of environmentalists and landfill operators. They are the target of state regulators. They are the fuel of choice for a growing number of cement and paper companies, and even some power plants. They have also surfaced at thousands of railroad crossings and even interested the King of Tonga as an item to import from the United States. Yet they are still most commonly matched with a gang of kids, a length of rope and a sturdy tree. They are waste tires.
With more than 240 million tires discarded annually in the United States and restrictions on disposal heightening with each new legislative session, more than two billion tires have piled up nationwide.
Stockpiling old tires is dangerous because of fire risk. One storage yard smoldered for more than a year. And used tires have never been a favorite of landfill operators. They have a tricky way of working to the surface of a landfill where they form a fertile breeding ground for mosquitoes and vermin. Many landfill sites refuse to accept large quantities of scrap tires. Others charge high fees to discourage their disposal. That leads to illegal dumping. It's estimated that only about 30 percent of used tires are recycled or disposed of properly. Recycling options include retreading and a variety of crumb rubber products. Riedel Omni Products (Portland, Ore.), a subsidiary of Riedel Environmental Technologies, is using rubber dust (a waste byproduct of the retreading process) to make track-separating panels at railroad switch points. The panels replace aging asphalt, concrete or wooden separators. This might be viewed as a limited market, but Omni President Ronald G. Nutting points out that there are more than 200,000 public-railroad crossings in the United States, of which only 1 percent have rubber panels.
Omni is also eyeing markets abroad and has installed crossings in Canada, the United Kingdom and Australia and has positioned sales representatives in the Pacific Rim. Production has steadily increased at Omni's three plants in Oregon, Texas and Pennsylvania and recycled rubber products have contributed more than $6 million in revenues for Reidel in each of the past two years.
At least two companies, however, argue that because most used tires cannot be remade into new tires, and because recycled product development is still slow and not economically promising, the only large-scale solution to the scrap tire problem is conversion into tire-derived fuel (TDF). Waste Recovery Inc. and Oxford Energy Co. are wagering that they create a significant market for TDF.
"Conversion of scrap tires into TDF is the only existing market currently experiencing significant growth," asserts J. Michael Kennedy Jr., a marketing manager for Waste Recovery. The Portland company has been shredding scrap tires since 1982, just after Oregon passed a law requiring shredding of all used tires before landfilling.
After 1986 Waste Recovery began to develop markets for TDF, processing the tires into a refined fuel supplement primarily for sale to cement companies and major domestic pulp and paper companies.
"By using TDF in existing facilities, there is no need to construct capital-intensive combustion units which would require new source emissions, debt liability or public subsidy of high utility rates," Kennedy says. Waste Recovery, which defines itself as the largest U.S. processor of scrap tires into quality fuel, has plants in Oregon, Texas and Georgia. The company is paid a disposal fee for processing the tires and charges for the fuel it develops, which is usually cheaper than alternative fossil fuels.
The Goodyear Tire & Rubber Co. is Waste Recovery's largest shareholder and manufacturer of about one-third of tires used in the domestic market. Goodyear's waste tires from its stores and truck retread centers are available to Waste Recovery.
Through one of its principal operating subsidiaries, Oxford Tire Recycling, the company also collects, shreds and recycles tires. Oxford operates the world's largest tire-fueled power plant, a 14-megawatt plant in Westley, Calif.
Grant Ferrier is editor of the San Diego-based Environmental Business Journal.