The dimension of the problem can be stated in round numbers. Every year we generate an additional 1.9 billion pounds. Any substantial new use for old tires can reduce and perhaps eliminate at least one source of pollution and marring of the landscape, although it is considered unlikely that any large portion of the existing stockpile will be used for the production of activated carbon. In adsorbing these toxics, carbon attaches them more or less firmly to its highly porous surfaces, which are very large. When the carbon is removed from the system it takes the impurity with it.
Typical adsorbates are acetone, trichloroethane, and compounds of mercury.
All are toxic in some degree, and any or all may be found in flue gases from power plants. Because old tires are in enormous supply, they have been the object of study for some time by chemical and environmental engineers. This gives us some idea of the potential contribution to commerce and to environmental cleanup. Some minor components are also present. The oil and gas are used to supply process heat, and the carbon is then activated.