The LCA modelling of chemical companies in the industrial symbiosis perspective: Allocation approaches and regulatory framework

The application of industrial symbiosis to chemical processes is made possible by considering physical by-products as new sources in spite of potential waste. The by-product acts as a substitution of raw materials in symbiotic chemical companies, possibly taking into account geographical proximity. While advantages appear evident in terms of reduced cost savings and resource consumption, benefits related to other environmental impacts seem to be less clear. This chapter deals with different case studies of industrial symbiosis and how these are treated according to literature, regulatory approaches and main guidelines. Once the different approaches and their range of applications are presented, the chapter describes the main barriers and strengths in the application of these rules to the chemical sector. Finally, the identified approaches are applied to a specific case of industrial symbiosis in the chemical sector by illustrating how the single data can be calculated and can quantitatively change. This chapter aims to guide the LCA practitioner through an agile set of rules in modelling industrial symbiosis in an LCA perspective and to provide a quantitative evaluation of the effects that a modelling choice may produce with respect to another.