Their rubber is also used to pad out children’s play areas. There are now other routes old tyres can take to get back into the economic circuit: retreading and regrooving; reuse for export; and incineration for energy.
In the last decade, because of their high calorific value–a tonne of tyres is equivalent to a tonne of good quality coal or to 0.7 tonnes of fuel oil–used tyres can act as a supplement fuel in pulp and paper mills, industrial boilers, cement kilns and power plants. Depending on the technology used, tyres can represent up to 25% of the total fuel of cement kilns. And tyres-to-energy power plants have been built in Europe and the US.
The market for tyre-derived fuel in the US has exceeded 150 million units for a decade now. Tyre recycling for civil engineering applications grew from half a million tyres in 1990 to 30 million in 2000. For instance, a worn-out tyre may be used in asphalt paving and road construction, which increases pavement life by four to five times. Europe has seen a similar trend. Old rubber tyres have energy left in them after all.
OECD (2006), Improving Recycling Markets, Paris. See www.oecdbookshop.org
©OECD Observer No 258/259, December 2006