Application of an Agent Based Model to Study the Resource Exchanges within Eco-industrial Parks

Industrial symbiosis (IS), emerges when diverse organizations interact to share resources with each other in order to increase their overall economic outcomes simultaneously reducing the overall environmental impact. However, it is difficult for companies to identify waste and potential resources. The European Union project SHAREBOX is developing an online platform that supports companies identifying each other resources and nucleate industrial symbiosis. When such opportunities are energy related, conversion technologies are typically required depending on nature of the energy resource and the mismatch between time of supply and user needs may necessitate energy storage. This research work focused on forecasting supply and demand time series as this data is important but typically difficult to obtain.

To model demand and supply time series, the Réseau agent-based model was developed. Here the agents; factories (internal agents), market buyers and market sellers (external agents) represent the players in the industrial ecosystems. The agents have dynamic behaviour (e.g. varying price) and heterogeneous characteristics (e.g. production method). Agents combine complex decision rationale with process models (here simplified as input-output model and maintaining the material and energy balance).

The decision strategies implemented in the model are; random seller selection and seller sells based on best price, random price changes and risk based price changes. The model was demonstrated on three different case studies with increasing complexity. Case study one demonstrated random decision strategies on single input single output industrial ecosystem. This validated the software concept. Case study two evaluates all combinations of decision strategies in and industrial ecosystem with factories that have multiple input multiple output. This showed that the risk based seller decision strategy developed in this work provides significantly more realistic demand and supply time series. This is independent on whether buyer choses the seller randomly or based on best price. For the third case study, Réseau was extended with multiple period contracts between factories within the ecosystem. We compared scenario with and without such contracts. This showed that the industrial ecosystem is more stable and the Symbiosis Relationship Index (the ratio between internal and external transaction) increased significantly when long duration contracts are available.
To summarise, I created Réseau a demand and supply simulation tool, to model the manufacturing processes and the decision rationale of players (agents) in the industrial ecosystem. The three case studies validate the software concept, demonstrate that the seller risk based decision criteria developed in this work generate the most realistic supply and demand time series and shows that contract based relationship between factories significantly increases the duration of industrial symbiosis. The output of Réseau is used in SHAREBOX to support identification of feasible industrial symbiosis projects.