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Uses of Discarded Tires as an Alternative Energy Source

Discarded tires, previously considered an "end-of-life" product and tossed into landfills, are now being used as a source of alternative energy. Like certain plastics, these durable rings are hard on the environment; they do not break down in landfills. According to the U.S. Environmental Protection Agency (EPA), approximately 290 million tires are tossed every year, so the process of using discarded tires to create tire-derived fuel (TDF) as an alternative energy source is a double boon for the environment, and TDF has several uses.

Supplemental Fuel
- Using discarded tires as alternative fuel can lower emissions.
  
  Companies that are over-polluting and not meeting their emissions limits can benefit from supplementing their fuel with TDF, a clean-burning alternative to oil and coal. "Alternative Energy eMagazine" explains that while emissions from metals such as lead and nickel are equivalent whether manufacturing plants are using TDF or not, testing estimates indicate that TDF greatly reduces carbon dioxide emissions, possibly by as much as 19.5 percent.
  
  TDF also has a lower sulfur content than coal. "The Almanac of Policy Issues" describes how sulfur forms sulfur dioxide when heated, which then becomes a major contributor to acid rain.
High Heat Manufacturing
- Tires have a heating value higher than coal.
  
  The EPA describes TDF as a beneficial alternative or supplemental fuel for manufacturers who use high heat to produce their products. They explain that kilns and furnaces, such as those used to manufacture cement, concrete, glass and paper, require high heating value fuels. Tires, according to an "Alternative Energy eMagazine" article about tire derived fuel, have a heating value that is significantly higher than both wood and coal, two commonly used heating fuels. These discarded tires even have a higher heating value than petroleum. Manufacturers can load shredded, cut or whole tires directly into large furnaces.
Transportation Fuels
- Petroleum can be recycled from discarded tires.
  
  According to "Earth911.com," one single tire contains approximately 10 gallons of petroleum-based oil. Petroleum is a finite commodity, so the ability to recycle and reuse the petroleum from discarded tires is paramount to extending one of Earth's major resources. Through pyrolysis --- the process of transforming or decomposing composites with heat --- tires can be converted to crude oil, which can also then be further processed into diesel and gasoline.
Electric Arc Furnace Fuel
- Used as alternative fuel for steel production, tires actually become part of the product.
  
  The Rubber Manufacturers Association explains how electric arc furnaces are used for the creation of high-carbon steel products --- including wire, pipe and tubing --- by combining iron with more than 0.5 percent carbon. Electric arc furnaces burn at temperatures over 3,000 degrees Fahrenheit. They further describe how discarded tires are an excellent alternative fuel source for the creation of steel due to three attributes: They have high carbon content, they are made with high-grade steel, and they have a high heating value. And in an electric arc furnace, most of each tire is actually incorporated into the steel leaving very little scrap to be discarded.

Nature