A comprehensive inventory of different materials has accumulated in buildings, infrastructures and long-life consumer goods in Germany over the past few decades, and is continuing to grow. This anthropogenic stock includes materials that are not only accumulated but also released at the end of product life cycles, and which make their way into waste treatment systems. However, stakeholders such as waste producers, collectors, handlers, processors and producers are rarely integrated vertically along the value chain and have very different interests and incentive systems which they use in their decision-making.
The aim is to make a systematic contribution to the further development of closed cycle management into a resource-saving material flow economy. The waste streams and outflows from the anthropogenic stock must be understood as secondary raw materials. The “disposal” material flow is considered from the end point, and the actors are involved in working out the conditions which must be fulfilled along the recycling chain in order to avoid downcycling where possible.
The systemic analysis initially deals with a predefined group of mineral construction and demolition waste materials (concrete, lime sandstone, aerated and lightweight concrete, brick, flat glass, insulation materials, gypsum building materials, plaster, mortar, tiles and ceramics) and base and special metals (rare-earth magnets, stainless steels and their alloy elements, brass, zinc, tin, aluminium and magnesium).
The second step involves dynamic modelling of the mass flows on the basis of scenarios for 2020, 2025 and 2030 in order to quantify the anthropogenic stock. The modelling identifies specific efficiency levels and losses, and gives an estimate of the recycling and disposal pathways which can be used, and to what extent.