Tire-derived fuel now in greater demand

by Brian R. Hook

Higher energy costs are driving demand for tire-derived fuel (TDF) across parts of the country, especially along the Gulf Coast into parts of the South Atlantic states.

“In part of the country, we’ve seen a very significant spike in the use of scrap tires as fuel,” said Michael Blumenthal, senior technical director at the Rubber Manufactures Association. He said the TDF market from Texas through Florida up to Virginia is basically sold out. “I’ve talked to a number TDF sales people and they can’t get enough supply. There is more demand for TDF than availability of TDF,” he said.

Blumenthal, who tracks the scrap-tire industry for the Washington D.C.–based rubber products trade association, said the main factor behind the demand is the rising cost of more traditional fuels. Also, the southern part of the country has a strong pulp-and-paper industry and there are a significant number of cement kilns in the region.

Pulp-and-paper mills consume a lot of energy. Mills often supplement wood fuels, which vary in heat values and moisture content, with other fuels such as coal or oil to stabilize operations. The mills use de-wired tires to avoid clogging the feed system.

The cement industry also burns scrap tires as fuel for its kilns, which are basically large furnaces.Some kilns are able to use whole tires, instead of using tire chips. The removal of steel from the tires is often unnecessary since kilns need iron for part of the process.

TDF is used as a supplement at both kilns and mills because of its low cost and its relative high-heat value, Blumenthal said. Tires have 15,000 Btu units per pound. In comparison, natural gas has 18,000 Btu’s per pound. It is estimated that tires produce 25 percent more energy than coal and the same amount of energy as oil.

President George W. Bush told the nation that the United States has a serious energy problem during his State of the Union Address in late January. For the first time President Bush said: “America is addicted to oil, which is often imported from unstable parts of the world. The best way to break this addiction is through technology.”

The challenge to find alternative fuels to replace oil by the President, however, is not the reason behind the current increase in the use of scrap tires as fuel, Blumenthal said. “I think the President is behind the curve as far as tire-derived fuel is concerned. Tire-derived fuel in the last couple of years has increased on a very nice scale.”

Blumenthal said he is currently gathering the results for his bi-annual study on the number of tires being used for fuel. He estimated that more than 290 million scrap tires were generated in the country in 2003. Nearly 100 million of those tires were recycled into new products and 130 million were used as tire-derived fuel in various facilities. That is about 45 percent of all generated tires, up from 25.9 million tires in 1991.

Blumenthal gets his information from both the public and private sectors. He first talks to state regulators. Then he double-checks the numbers with the major suppliers of TDF. “I don’t have any published data yet. But I do know that there are more facilities using tires today than there were a couple of years ago,” Blumenthal said.

“Because of the increase in TDF, we’re going to see a slight decline in tires going into other applications,” he said. “There are only so many tires.” Blumenthal said the scrap-tire industry is still very regionally orientated. Other types of facilities using TDF include industrial boilers and large-scale utility boilers. Blumenthal said his preliminary research shows that these markets have remained stable over the last few years.

The Energy Information Administration estimates that TDF consumption across the country in 2004 was 38.4 trillion Btu’s for electric only plants, combined heat and power plants, and steam only plants. The statistical agency for the U.S. Department of Energy in Washington D.C. does not follow the entire TDF market across the country.

Fred Mayes, chief of the renewable information team at the EIA, said TDF is too small of a market for the agency to track. Therefore the agency estimates the use of TDF as one of the fuel sources in a category it refers to as non-electric renewable energy.

“When costs go up, you have to reassess all fuels and things that were previously not usable suddenly may have a value,” Mayes said. He said some of the costs related to using tires as fuel should be allocated to waste disposal. “With waste of any kind, part of the cost of energy that you get out of them is just a waste disposal cost. Those can be kind of difficult to determine, but that cost is there.”

The U.S. Environmental Protection Agency (EPA) would prefer to have all tires recycled. Roxanne Smith, an EPA spokeswoman, said it is not possible to recycle some tires. She said it is better to recover the energy than landfill the tires. The EPA estimates ash residues from TDF may contain lower heavy metals content than some coals.

International Paper Co. wants to add another TDF facility to its portfolio of eight pulp-and-paper mills across the country. The Stamford, Connecticut-based paper and forest products company wants to test TDF at its mill in Essex County, New York. Donna Wadsworth, a spokeswoman for International Paper, said the project has been delayed from gaining approval due to opposition from next-door state officials in Vermont.

International Paper would not reveal details of its fuel mix for specific facilities, citing competitive reasons. It would also not reveal whether the levels are higher or lower than in the past. But the company estimates the TDF project in New York would provide fuel costs savings of $3.7 million a year by supplementing its current mix with TDF.

International Paper also estimates that TDF at the New York facility would consist of small chips of processed scrap tire with 95 to 98 percent of the bead wire removed. The material would be fed into the boiler along with bark. Anticipated volume usage of TDF would be three tons per hour, representing 10 percent of the fuel mix.