Tyred and emotional in Illinois
15 Jan 2000
Researchers from the University of Illinois and the Illinois State Geological Survey have developed a method for turning discarded tyres into activated carbon, which in turn can be used to remove pollutants from stack emissions.
In a report published in the American Chemical Society journal Energy and Fuels, the researchers describe the scale of the problem: there are between 2billion and 3billion waste tyres in the US, either stockpiled or languishing in landfills, and over 240million are added to this every year. Stack one on top of the other, and they'll reach to the moon.
The Illinois team sees this problem as a resource. `Tyre rubber could be an ideal material to make activated carbon,' comments Mark Rood of the University of Illinois. `It is inexpensive, it has a high carbon content, and it has low ash and sulphur contents.' Previous research into recycling waste tyres has focused on ways of recovering hydrocarbon fluids.
Activated carbon is generally made by treating coal, or burned wood or nutshells. Tests by the Illinois team indicate that tyre-derived carbon can adsorb more mercury vapour than coal-derived activated carbon.
