A preliminary study on System Dynamics approach for Industrial Symbiosis in Iron and Steel complex industrial systems
The 9th biennial conference of the International Society for Industrial Ecology (ISIE) and the 25th annual conference of the International Symposium on Sustainable Systems and Technology (ISSST), Chicago, Illinois, USA from June 25-29, 2017.
The iron and steel industry is one of the well-known energy-intensive sectors which have a strong involvement in energy savings and environmental impacts reduction. Many efforts are continuously carried out in this sense to improve the global energy efficiency of integrated iron and steel production sites by optimizing their internal processes and multiplying exchanges with the surrounding. The implementation of internal material recycling loops (e.g. iron and steel production by-products and wastes streams) and the set of internal energy recovery systems (e.g. waste heat recovery and gas flare avoidance) are thus facilitated. Connections with external sectors such as the cement industry (e.g. blast furnaces slags reuse) and recycling activities (e.g. steel scraps reuse in electric arc furnaces in the recycling production route of steel) have also been setting up to lower the environmental impact of iron and steel industry since several years. When going further with regard to these specific external links, concrete and successful examples of Industrial Symbiosis (IS) involving iron and steel industry and leading to energy consumption and environmental impact reduction can be found. This research is particularly focused on the ArcelorMittal Dunkirk’s integrated iron and steel production site (Nord-Pas-de-Calais, North of France). It aims at assessing the effectiveness and performances of potential IS implementations which is considered as a key step in the decision-making process regarding the competitiveness improvement of industrial sites. A methodology is thus proposed to quantify and to highlight over time the environmental and cost benefits that can be achieved through concrete and new IS scenarios. Relying on a great experience in performing resource sharing efficiently within a common territory, historical and sustainable IS that has been existing since several years in the Dunkirk’s ecosystem is used to calibrate this research in the first development stage. The methodology is mainly based on System Dynamics (SD) approach that allows to model complex adaptive systems while identifying information feedback characteristics of industrial activities to deduce their complex behaviors. It also permits to address both the technical and non-technical aspects of IS problems by dealing respectively with hard variables (e.g. variables easily quantifiable such as production outputs) and soft variables (e.g. variables not easily quantifiable such as the trust between two partners). In this presentation, a primary simple SD model will be introduced to describe the iron and steel IS system structure through the ArcelorMittal Dunkirk case. This model is built by using mental models called causal loop diagrams (qualitative assessments by looking at the feedback loops) and allows the building of a simulation model known as stock and flow diagram (quantitative assessment by looking at the dynamical variables). This model is used as a support to the preliminary SD analysis whose expected results consist of a detailed overview of the relationships between the core variables of the IS system structure. The interaction between organizations, policies, and time delays will be depicted over time to show how it influence the success of IS scenarios in iron and steel production site.