TA11B Modeling of Recycling and Waste Management
C123
8:00 AM - 12:00 PM, Tuesday
() Modeling choices for recycling and implications for decision-making.
Rebitzer, G.1, Buxmann, K.2, Kistler, P.3, 1 Alcan Technology & Management, Chippis, Switzerland2 Alcan Technology & Management, Chippis, Switzerland3 Alcan Inc., Montreal, Canada
ABSTRACT- Life cycle assessment (LCA) is an emerging and evolving tool for assessing the environmental impacts of goods and services. In LCA, the specific modeling of recycling processes within the life cycle inventory analysis can highly influence the overall results. Because of this, the associated methodological choices have to be justified in alignment with the goal and scope of the study and thus with the intended use(s) of the LCA results. At Alcan, one of the world's leading suppliers of aluminum metals and products as well as composite components, LCA is used for a variety of applications and in different decision contexts. It is well known that the environmental performance of aluminum-based products is dependent to a high degree on recycling activities. Therefore, for most of Alcan's products, the recycling phase is of utmost environmental importance and special care has to be taken in choosing the models that most appropriately represent reality in relation to the specific decision to be supported. Different approaches for modeling recycling activities exists: the consideration of the recycled content of a product and the consideration of the specific recycling activities at the end-of-life of a product. While the former corresponds to the so-called attributional (historical) LCA, the latter is relevant for consequential (change-oriented, prospective) modeling. The presentation will discuss differences between these two approaches in the context of corporate decision-making. Examples will be presented comparing both approaches in regards to 'pure' LCA indicator results and in regards to decision-making and 'real-world' effects. It will be shown that the appropriate choice of the modeling method is crucial for sound decisions and that for decisions which aim at improving the environmental performance of products only the consequential approach leads to a valid modeling of recycling processes. In addition, the implications for selecting and modifying datasets to be used in the life cycle inventory analysis will be elaborated.
Key words: consequential LCA, recycling, aluminium, decision-making