How does a responsible society deal with waste streams in the most sustainable way? How does it dispose of plastic waste, electronics, organic material and tires?
The most common way to deal with waste is to apply the waste hierarchy – a set of priorities for the efficient use of resources.
The best solution – reduction – avoids waste as much as possible by reducing consumption. For tires, this would imply a reduction of vehicle traffic. Bearing in mind current global economic growth, especially outside the EU and USA, this option does not seem very realistic in the near future.
Second best would be to reuse, wholly or in part, like we do with glass bottles. For tires, this is called retreading. – New rubber tread is laid on the inner body of the tire, the casing. Retreading gives the tire a new life. Regardless of the quality of the casing, a tire can be retreaded only a few times. The tire is scrapped when the casing is worn out.
Third best choice, according to the waste hierarchy, is to separate and recycle the original materials. For tires, these materials are rubber, steel and textile fibers. Genan separates these materials at its plants. The recycled material is then used effectively to avoid production with new virgin rubber and steel.
Fourth best choice is to use the material for energy recovery. This is not as sustainable as material recycling as the product is destroyed in the process and only a fraction of the energy originally invested in the production of the product is recovered. Tires are widely used for energy recovery in cement kilns. This is called co-incineration.
Landfilling is the worst choice possible. Even so, this method is still widely used across the globe. Landfilling tires is a particularly poor solution. Tires take up a lot of space, they are not biodegradable and they are an excellent breeding ground for insects and vermin. Landfilling tires was banned in the EU in 2003.
The waste hierarchy is integrated into EU legislation as EU Directive 2008/98. It is also being implemented as environmental legislation in other parts of the world. EU Member States are obliged to aim to use waste disposal solutions as high up in the hierarchy as possible. The scientific tool used to measure the impact of different waste disposal solutions is called Life Cycle Assessment.