U.S. Recycled 71 Percent Of Scrap Tires In 1999.

Last year, scrap-tire management systems captured 71 percent of the 272 million scrap tires generated in the United States, according to Terry Noteboom, senior environmental engineer for Goodyear Tire & Rubber Co.

"These statistics demonstrate that the industry is doing a good

Because tires and rubber products in general are not biodegradable, Goodyear engineers are working on scrap tire management options as part of the company's corporate goals, he added.

"Currently, energy recovery provides the best opportunity to resolve the scrap-tire issue, and it is in use throughout North America and Europe," Noteboom said.

Scrap tires are used as a supplemental fuel by cement, electricity and paper producers, and their combustion reduces solid waste and air emissions, he said.

In addition, ground-tire rubber is used in civil engineering applications, such as asphalt paving and playground surfaces.

Goodyear has developed a number of uses for whole scrap tires, including floating breakwaters, tire reefs, crash barriers and playground equipment, Noteboom said. "Although projects of this type reuse scrap tires, demand for them remains pretty static and simply is not growing."

During the second half of the 1990s, Goodyear researchers discovered, refined and patented a process to devulcanize rubber from cured products, such as tires, belts and hoses. In tests conducted on a laboratory scale, more than 90 percent of the material was recovered while keeping the microstructure intact, Mr. Noteboom explained.