Environmental assessment of the Sotenäs Industrial Symbiosis Network

On the west coast of Sweden, an evolving network of industrial actors is being developed to create green, local jobs while contributing to a sustainable future. Industrial symbiosis (IS) is being promoted by the Sotenäs Symbioscentrum (Sotenäs Symbiosis Center) to develop synergies between industrial actors involved in renewable energy, food production, aquaculture, algae production and marine technology in order to improve material and energy efficiency in the region. It is anticipated that the current, developing and future synergies will lead to environmental benefits for the region and ensure a sustainable seafood and marine industry in the region. Therefore, this study aims to assess and review the environmental implications of the IS network in the Sotenäs region by outlining the potential environmental benefits and impacts of the evolving IS network.

In order to review the environmental implications of the Sotenäs IS network, life cycle assessment (LCA) was used and applied to the network. The assessment of the environmental impacts (and benefits) of the industrial symbiosis network follows the methodology outlined in Martin et al. (2015) for LCA of IS networks. Using this method allows for the review of both the impacts from the network (as a whole) and the benefit for individual firms in the network. The results of this study suggest that the Sotenäs IS network has potential to significantly reduce environmental impacts for the production system currently being developed, when compared to a reference system. Large reductions in greenhouse gas emissions and local impacts, namely eutrophication impacts are possible. Examples include large impact reductions from land based salmon production compared to conventional salmon farming and adding value to fish industry waste through biogas, and thereafter biofertilizer, production.

The extent of the reductions include:
• A reduction of nearly 60 million kg CO2-eq emissions
• Eutrophication impact reductions of 388 thousand kg PO4-eq
• Reduction of over 19 million tonne-km in transportation of wastes and other products

All firms within the network were shown to benefit from the sharing of resources and energy, thus highlighting the importance of the IS network for improving the performance of the firms involved and the products being produced. In addition to reduced impacts, there is a significant potential for reduction in transportation from the firms due to integration.

It is also important to note the significance of the nutrient recycling of the network by cascading wastes and wastewater to extract nutrients and reduce local impacts. With Sotenäs being a fishing community, the symbiotic network thus improves the use of sea-based resources and reduces the potential impacts to the aquatic and natural environment. Central to the system, the biogas plant act as an “upcycling tenant” in the IS network to further improve environmental benefits through wastewater and by-product handling in addition to replacing and supplying tradition forms of heat and fertilizer. Results from the project will be important to spread to further municipalities in order speed up their local work with facilitating industrial symbiosis and to understand how these networks can be assessed both quantitatively and qualitatively from a number of important aspects.