Efficiency measures of industrial symbiosis network using enterprise input-output analysis

An important challenge that firms should be able to sustain regards mitigating the environmentalimpact of their production processes. Industrial symbiosis is a way that allows firms to approach thisgoal and, at the same time, to obtain economic benefits in terms of cost reduction (Chertow, 2000).The topic of industrial symbiosis networks (ISNs) has been addressed in the industrial ecologyliterature (Chertow and Ehrenfeld, 2012; Romano et al. 2012) but efficiency measures need to bemore explored in order to drive the ISN design and development. Park and Behera (2014) providesome insights about the methodological aspects related to the use of eco-efficiency indicators forISNs.In this paper we propose a measure of efficiency at the level of each specific symbiosis relationshipbased on the exchange of materials and energy. Then, based on the enterprise input-output (EIO)approach, we extend the definition of efficiency at the level of the entire ISN. We analyse several types of network in terms of topology, number of firms, and technicalcoefficients. In particular, ISN efficiency can be strongly affected by the network topology andtechnical coefficients. Then, various ways to improve efficiency of a symbiotic network have beenrecognized, resulting in policy recommendations. This approach has been applied to a couple of ISN, the conversion of biomass and exhausted tyresinto energy, getting information about the most efficient balance between waste production andprimary input requirements