Mixed-Integer Optimization of Material and Energy Integrations in an Eco-Park Network

The concept of industrial integration of material and energy flows is based around improved efficiency across a range of processing facilities with the end goal of better environmental performance without compromising profitability. This research project has focused on quantifying the benefits of synergistic collaboration of a sampling of potential neighbouring industrial facilities and has shown the effects to be beneficial in both the economic and environmental domains. The resulting model has demonstrated the potential reduction life-cycle emissions to land, water and air by approximately 40% while maintaining profitability at or above previous levels. The dual-objective function contained within the optimization creates a balance between the economic and environmental considerations that is benchmarked to a non-integrated group of similar-sized facilities. This type of objective function highlights the cumulative relative benefits and drawbacks of each producer participating in such an arrangement. Modeling of such industrial ‘eco-parks’ as a linear optimization problem has shown that integrating industrial processes across several manufacturers is beneficial for economics as well as for environmental initiatives. In order to incorporate additional complexity and to analyze the costs of adding network nodes at variable distances in addition to other features, the optimization routine has been advanced to a mixed-integer problem to more realistically reflect the addition of incremental units of industrial operations. Mixed-integer modeling allows for increased model flexibility to add discrete plant sizes, transportation distances, technology selection, fuel selection and several other considerations. In the work presented here, the mixed-integer result is compared to that of the linear problem.