Assessing the future potential of waste flows – case study scrap tires

Abstract

Our planet has limited resources, and due to our increasing demands on a variety of products, we rely on the availability of primary and secondary resources. This paper will give an overview on the required information received from processing secondary resources. It is possible to assess the quality of the generated material fl ows with this information. By describing the material characteristics and the material fl ow uncertainties, a forecast of the material’s future potential to replace primary resources may be possible. Future prospects of the quality of secondary resources, including their input and output properties may be helpful to assess their potential to substitute primary resource for example. It is the contribution of the paper to point out the necessity of knowing the whole life cycle of a product to gain the best available end-of-life option. The case study of scrap tire recycling gives an example of assessing the material’s properties. Modeling recycling processes offers the potential of identifying the processing steps with regard to the main material fl ows and emissions to reduce the environmental impact and improve the economics. Material fl ow analysis and life cycle assessment can support the determination of the future potential of waste streams entering the recycling process. Some material fl ows are appropriate to replace primary resources without loss of quality. But other materials are only useful for products with minor quality. Some materials are made to never separate by itself, and therefore pure material fl ows are impossible to achieve. A model that considers different material properties of material fl ows helps to evaluate the global recycling potential. Therefore, material qualities have to be defi ned to make an assessment of sustainable management of secondary resources possible. A concept of developing a model that addresses this issue is presented in this paper. The aim of the model is to predict secondary material fl ows that are of equal quality of primary material fl ows. These material fl ows are then suitable to substitute primary resources which results in global savings in resources, both material and energy.