The three major markets for scrap tires expanded in the 1998-2001 period, while the total number of stockpiled used tires remained about the same, according to a soon-to-be-released scrap tire market study.
Besides the growth of tire-derived fuel, ground rubber and civil engineering applications, the report from the Rubber Manufacturers Association found that 77.6 percent of all scrap tires generated in 2001 were reused, recovered or recycled into an end product, said Michael Blumenthal, RMA senior technical adviser.
The scrap tire stockpile through 2001 stood at 306 million tires, the same as in 1998. However, the 2001 figure includes some storage sites that were overlooked in the report for 1998.
Last year the number of tires recycled into ground rubber grew 120 percent to 33 million units, largely because of greater demand for 5/8-, 3/4- and 1/2-inch pieces used in playground surfaces, horse arena flooring, running tracks, soil amendments and horticultural applications, Blumenthal said.
Scrap tire usage in civil engineering applications doubled since 1998 to 40 million units as tire shreds were used for road embankments and in landfill construction projects.
While TDF usage increased only slightly to 115 million tires from 114 million, Blumenthal said the sector still grew despite overcapacity and consolidation in the paper and pulp industries, which caused many mills to shut down. The Enron Corp. scandal further impacted the TDF market by causing utility companies to scale back on costs.
Cement kilns, which in 1998 were not a big end-user of TDF, helped compensate for the downturn in TDF demand in the paper and pulp industries.
``Where we've made up ground is in the cement industry, which a couple of years ago was a soft spot because of the strong economy and the fact that a lot of cement kilns are at full capacity,'' he said.
``They weren't that interested in tires because they wanted to make it as convenient for themselves to make cement as possible. Now a lot of kilns are looking to save money and increase efficiency. Once again, tires became a component of that management theme.''
Tire shreds cost less for cement kilns than coal, Blumenthal said, and help increase production capacity because of the amount of heat generated in the kilns.
Blumenthal said states cleaned up millions of tires in recent years, but the factor that caused the estimate to remain the same is that two states-Colorado and Connecticut-each have begun to count existing storage sites as abandoned.
It has become apparent, he added, that 85 percent of stockpiled tires are concentrated in nine states: Texas, New York, Michigan, Alabama, Ohio, Colorado, Connecticut, Pennsylvania and West Virginia.
Blumenthal won't predict when the U.S. will reach a point of 100-percent recycling and reuse of scrap tires generated, but he said the RMA will continue to work with state governments to help achieve that goal.
``I think we're in a good position now,'' he said. ``We have created a lot of new information and training courses that the RMA has which we're taking into the field. We're working with all kinds of federal and state agencies on these training courses.''