Scientific abstract:

Material flow analysis (MFA) has been an effective approach for industrial ecology. Due to the increasing number of research questions and fields of industrial transformation, more methodological integrations and extensions are still required. Herein, this study presents three integrated MFA models, which have been derived and applied on three case studies. First, an intersectoral MFA model is developed to investigate the impacts and interdependencies of the transition of the energy system and the implementation of a circular economy. For example, the shift towards green steel will have an impact on the availability of blast furnace slag, which is used to produce CEM II and III. Also, the coal phase-out act in Germany will affect the amounts of fly ash and FGD gypsum. Herein, the model’s framework consists of three consecutive steps. First, the production processes are studied and the relevant inflows, outflows and stocks are determined. Second, the identified inflows and outflows are quantified. Finally, the alterations caused by the industrial transformation are analyzed. The presented model and analyses can help the policymakers and strategists to understand the intra- and intersectoral relations, impacts of relevant policies, and the associated changes in the material and emission flows.