Industrial Waste Reuse and By‐product Synergy Optimization

By‐product synergy is a growing practice worldwide. It consists in the maximization of resources utilization with the replacement of raw materials by by‐products as inputs for industrial processes. In order to support decision making in such strategic projects, appropriate tools must be developed. This article presents the results of a research project, which includes the development of a multiobjective mathematical programming model for the optimization of by‐product flows, synergy configurations, and investment decisions in eco‐industrial networks. This model is evaluated using data related to the Kalundborg industrial symbiosis (IS) in order to illustrate its utilization, as well as to assess, in a retrospective manner, the behavior of the companies involved with respect to both economic and environmental benefits of synergies. The experiments also illustrate the influence of the municipality on synergy implementation and how a scenario‐based approach can be used to anticipate raw material price increase. The results are generally coherent with the actual timing of synergy initializations. Further, the considerable effect of water price on the length of investments’ payback period illustrates the impact of policies and regulations on IS.     

“Uncovering” Industrial Symbiosis

Since 1989, efforts to understand the nature of interfirm resource sharing in the form of industrial symbiosis and to replicate in a deliberate way what was largely self‐organizing in Kalundborg, Denmark have followed many paths, some with much success and some with very little. This article provides a historical view of the motivations and means for pursuing industrial symbiosis—defined to include physical exchanges of materials, energy, water, and by‐products among diversified clusters of firms. It finds that “uncovering” existing symbioses has led to more sustainable industrial development than attempts to design and build eco‐industrial parks incorporating physical exchanges. By examining 15 proposed projects brought to national and international attention by the U.S. President's Council on Sustainable Development beginning in the early 1990s, and contrasting these with another 12 projects observed to share more elements of self‐organization, recommendations are offered to stimulate the identification and uncovering of already existing “kernels” of symbiosis. In addition, policies and practices are suggested to identify early‐stage precursors of potentially larger symbioses that can be nurtured and developed further. The article concludes that environmentally and economically desirable symbiotic exchanges are all around us and now we must shift our gaze to find and foster them.     

‘Habitat’ Suitability Index Mapping for Industrial Symbiosis Planning

By ‘working with the willing’, the National Industrial Symbiosis Programme (NISP) has successfully facilitated industrial symbiosis throughout the United Kingdom and, in the process, delivered significant economic and environmental benefits for both Programme members and the country as a whole. One of the keys to NISP's success is that, unlike failed attempts to plan and construct eco‐industrial systems from scratch, the Programme works largely with existing companies who have already settled in, developed, and successfully operate within a given locale. This article argues that existing and mature industrial systems provide the best prospects for identifying opportunities for, and ultimately facilitating, industrial symbiosis. Due to levels of diversification and operational fundamental niches that, in the fullness of time, develop within all industrial systems, industrially mature areas are deemed to be industrial symbiosis ‘conducive environments’. Building on the conservation biology concept of a habitat suitability index, the article presents a methodology for comparing a potential site for eco‐industrial development to a known baseline industrial ‘habitat’ already identified as being highly conducive to industrial symbiosis. The suitability index methodology is further developed and applied to a multi‐criteria evaluation geographic information system to produce a ‘habitat’ suitability map that allows practitioners to quickly identify potential industrial symbiosis hotspots (the methodology is illustrated for England). The article concludes by providing options for the development of symbiosis suitability indices and how they can be used to support the facilitation of industrial symbiosis and regional resource efficiency.     

Assessing the “Short Mental Distance” in Eco‐Industrial Networks

Like many economic exchanges, industrial symbiosis (IS) is thought to be influenced by social relationships and shared norms among actors in a network. While many implicit references to social characteristics exist throughout the literature, there have been few explicit attempts to operationalize and measure the concepts. The “short mental distance,”“trust,”“openness,” and “communication” recorded among managers in Kalundborg, Denmark, set a precedent for examining and encouraging social interactions among key personnel in the dozens of eco‐industrial networks around the world. In this article we explore the relationships among various aspects of social embeddedness, social capital, and IS. We develop a conceptual framework and an approach using quantitative and qualitative methods to identify and measure these social characteristics, including social network structure, communication, and similarities in norms and conceptions of waste, and apply them in an industrial network in Nanjangud, South India. The findings suggest that there is a fairly high level of shared norms about dealing with waste—the “short mental distance”—in this network, but by‐product transactions are only weakly correlated with the structure and content of communication among managers. Replication of this approach can increase the understanding and comparability of the role of social characteristics in eco‐industrial activities around the world.     

Industrial Recycling Networks as Starting Points for Broader Sustainability‐Oriented Cooperation?

Closing loops by intercompany recycling of by‐products is a core theme of industrial ecology (IE). This article considers whether industrial recycling networks or industrial symbiosis projects can be used as a starting point for much broader intercompany cooperation for sustainable development. Evidence presented is based on the results of an empirical investigation of the recycling network Styria in Austria, the recycling network Oldenburger Münsterland in Germany, and the manufacturing sector in Austria. Statistical analysis shows that the percentage of by‐products that are passed on to other companies for recycling purposes is not higher in member companies of the recycling networks than in the other companies of the manufacturing sector in Austria. In terms of cooperation, the relationships with the respective recycling partners are found to be very similar to regular customer relations. Furthermore, the companies of the recycling networks remain unaware of the network to which they belong. Instead, one of the main findings of this study is that intercompany recycling activities are regarded by the company representatives as bilateral market transactions, not as collaborative network activities. This has potentially significant implications for the use of industrial symbiosis networks as starting points for sustainability networks with broader cooperation toward sustainability. The findings raise interesting questions as to whether such broader cooperation might result from a conscious planning process or might emerge largely spontaneously as part of normal market coordination. In any case, intercompany recycling is clearly considered to be a very important field of collaborative action for sustainability in industry.     

The Impact of Scale,Recycling Boundary,and Type of Waste on Symbiosis and Recycling

Innovative waste recycling through industrial processes such as industrial and urban symbiosis has long been practiced and recently received much attention in the field of industrial ecology, with researchers making efforts to identify key contributing factors to successful industrial symbiosis. By analyzing 88 sample recycling projects in 23 eco‐towns in Japan, this article focuses on the factors of project scale, recycling boundary, and types of waste in relationship to environmental benefits and operational performance. The results showed that larger eco‐towns achieved more savings of virgin materials and higher stability in operation. Large‐scale projects tended to locate closer to the users of recycled products than did small‐scale projects. For treating similar types of waste, projects producing recycled products for special users (e.g., feedstock to a blast furnace for iron production) tended to locate closer to the users than those not producing for special users. The type of waste had a strong effect on the savings of virgin materials and recycling boundaries, while local factors had significant impacts on operational performance. The results also showed that agglomeration did not significantly contribute to the environmental benefits or operational performance of eco‐town projects. Another finding was that national agencies were helpful for facilitating cross‐prefecture transportation and long‐distance transaction of wastes. Implications of the findings are also discussed.     

Framework for Applying a Complex Adaptive System Approach to Model the Operation of Eco‐Industrial Parks

Models of eco‐industrial parks (EIPs) might help us transform our production systems by fostering the emergence of sustainable EIPs since such models have the potential to support the decision‐making processes of cooperative companies that participate and to decrease operational uncertainties. In this article, a conceptual framework for modeling the operation of EIPs is presented. The framework is underpinned by complex adaptive systems theory, industrial ecology, and an analysis of the experiences of existing EIPs. The proposed framework draws on the observed strengths of two types of industrial symbiosis models—planned eco‐industrial parks (PEIPs) and EIPs that developed through self‐organizing symbiosis (SOS)—as well as their observed weaknesses and the features of complex adaptive systems. From this analysis, five key properties to be modeled are deduced: functionality, reliability, life span, theoretical knowledge, and adaptability. It is proposed that the properties of functionality and theoretical knowledge are determined by the goals of the EIP and its member companies, while the property of adaptability is determined by the understanding that the companies in an EIP have of the environment surrounding the EIP, while the properties of reliability and life span are determined by the internal and external relationships of the companies that make up an EIP.     

Methodological Aspects of Applying Life Cycle Assessment to Industrial Symbioses

In view of recent studies of the historical development and current status of industrial symbiosis (IS), life cycle assessment (LCA) is proposed as a general framework for quantifying the environmental performance of by‐product exchange. Recent guidelines for LCA (International Reference Life Cycle Data System [ILCD] guidelines) are applied to answer the main research questions in the IS literature reviewed. A typology of five main research questions is proposed: (1) analysis, (2) improvement, and (3) expansion of existing systems; (4) design of new eco‐industrial parks, and (5) restructuring of circular economies. The LCA guidelines were found useful in framing the question and choosing an appropriate reference case for comparison. The selection of a correct reference case reduces the risk of overestimating the benefits of by‐product exchange. In the analysis of existing systems, environmentally extended input‐output analysis (EEIOA) can be used to streamline the analysis and provide an industry average baseline for comparison. However, when large‐scale changes are applied to the system, more sophisticated tools are necessary for assessment of the consequences, from market analysis to general equilibrium modeling and future scenario work. Such a rigorous application of systems analysis was not found in the current IS literature, but would benefit the field substantially, especially when the environmental impact of large‐scale economic changes is analyzed.     

Understanding the Evolution of Industrial Symbiosis Research

This study analyzes the evolution of the research field of industrial symbiosis (IS). We elucidate its embedding in industrial ecology (IE), trace the development of research themes, and reveal the evolution of the research network through analysis of the core literature and journals that appeared from 1997 to 2012 by citation analysis, cocitation analysis, and network analysis. In the first period (1997–2005), IS research held a minority share in the IE literature. The research revolved around the concept of IS, the assessment of eco‐industrial park projects, and the establishment of waste treatment and recycling networks. In the second period (2006–2012), diverse research approaches and theories enriched the field, which has led to a maturation in theory building. Our findings clearly illustrate that IS evolved from practice‐oriented research toward coherent theory building through a systematic underpinning and linking of diverse topics. As scientific attention shifted from exploring a phenomenon to elucidating underlying mechanisms, IS knowledge found worldwide practical implementation. The coauthorship network shows that the academic communities of IS are distributed worldwide and that international collaboration is widespread. Through bibliometric and network analysis of IS, we have created a systemic, quantitative image of the evolution of the IS research field and community, which gives IS researchers an underpinned overview of the IS research and may help them to identify new directions and synergy in worldwide research.     

Barriers to Industrial Symbiosis: Insights from the Use of a Maturity Grid

The concept of industrial symbiosis (IS) over the last 20 years has become a well‐recognized approach for environmental improvements at the regional level. Many technical solutions for waste and by‐product material, water, and energy reuse between neighboring industries (so‐called synergies) have been discovered and applied in the IS examples from all over the world. However, the potential for uptake of new synergies in the regions is often limited by a range of nontechnical barriers. These barriers include environmental regulation, lack of cooperation and trust between industries in the area, economic barriers, and lack of information sharing. Although several approaches to help identify and overcome some of the nontechnical barriers were examined, no methodology was found that systematically assessed and tracked the barriers to guide the progress of IS development. This article presents a new tool—IS maturity grid—to tackle this issue in the regional IS studies. The tool helps monitor and assess the level of regional industrial collaboration and also indicates a potential path for further improvements and development in an industrial region, depending on where that region currently lies in the grid. The application of the developed tool to the Gladstone industrial region of Queensland, Australia, is presented in the article. It showed that Gladstone is at the third (active) stage of five stages of maturity, with cooperation and trust among industries the strongest characteristic and information barriers the characteristic for greatest improvement.     

Revealing the Environmental Advantages of Industrial Symbiosis in Wood‐Based Bioeconomy Networks: An Assessment From a Life Cycle Perspective

The German government has recently initiated funding schemes that incentivize strategies for wood‐based bioeconomy regions. Regional wood and chemical industries have been encouraged to act symbiotically, that is, share pilot plant facilities, couple processes where feasible, and cascade woody feedstock throughout their process networks. However, during the planning stages of these bioeconomy regions, options need to be assessed for sustainably integrating processes and energy integration between the various industries that produce bio‐based polymers and engineered wood products. The aim of this paper is to identify the environmental sustainability of industrial symbiosis for producing high‐value‐added, bio‐based products in the wood‐based bioeconomy region of Central Germany. An analysis was conducted of three possible future scenarios with varying degrees of symbiosis in the bioeconomy network. A life cycle assessment (LCA) approach was used to compare these three scenarios to a traditional fossil‐based production system. Eleven environmental impact categories were considered. The results show that, in most cases, the bioeconomy network outperformed the fossil‐based production system, mitigating environmental impacts by 25% to 130%.     

Evaluation and Allocation of Greenhouse Gas Reductions in Industrial Symbiosis

Industrial symbiosis (IS) exchanges have been recognized to reduce greenhouse gas (GHG) emission, though methods for quantification of GHG emissions in IS exchanges are varied, and no standardized methods are available. This article proposes a practical approach to quantify total and allocated GHG emissions from IS exchanges by integrating the GHG protocol and life cycle assessment. The proposed method expands the system boundaries to include all IS companies, and the functional flow is set to be the sum of the main products. The total impact of a company is allocated to the main product. Three by‐product impact allocation methods of cutoff, avoidance, and 50/50 are proposed, and the total and distributed impacts of the IS systems in an industrial park are theoretically derived. The proposed method was tested to quantify GHG reduction in a real IS exchange developed between Korea Zinc (a zinc smelter) and Hankook Paper (a paper mill company) in the Ulsan Eco‐Industrial Park initiative. The total reduction of GHG emissions in this IS exchange, 60,522 tonnes of carbon dioxide per year, was the same in the GHG protocol, whereas GHG distribution between two companies depended on the allocation method. Given that the reduction of GHG emissions from IS exchanges is the product of the collaboration of giving companies and receiving companies, the 50/50 allocation method is best from an equivalent‐responsibility and benefit‐sharing perspective. However, this study suggests a more practical implementation approach based on a flexible and negotiable method of allocating the total GHG reduction between stakeholders.     

Industrial symbiosis in the forestry sector: A case study in southern Brazil

Industrial symbiosis (IS) is an important concept in the field of industrial ecology that has disseminated worldwide as a practice to decrease the ecological impact of industrial processes through the exchange of by‐products and waste between units in a system. The forestry industry is the main economic activity in the region of Lages in southern Brazil. IS relationships have expanded with the use of waste material from wood processing and strengthened cooperation between companies in different sectors. The aims of this article were to: a) quantify the level of IS in the system, b) identify the benefits of IS for participants, and c) explain why the network further developed IS to the formation of an industrial ecosystem. A questionnaire was administered during visits to 24 forestry companies in order to analyze their products and processes, commercial relations, positive impacts, and local insertion. The industrial symbiosis indicator (ISI) was determined using waste stream data from the system to represent the level of symbiosis among the companies in this region. The results show that the companies participate in a symbiotic network, mainly involving the exchange of chips, bark, sawdust and shavings. In most cases, these exchanges occur between nearby companies, constituting an extensive industrial ecosystem.     

Nestedness of eco‐industrial networks: Exploring linkage distribution to promote sustainable industrial growth

Eco‐industrial networks (EINs, of which eco‐industrial parks are a subset) have gained support as a solution that simultaneously reduces environmental burdens and promotes economic interests. EINs operate under a mutualistic framework, where waste materials and energy are exchanged between industries to their mutual benefit, creating a diverse web of flows. Recent studies have focused on analogies between food webs (FWs) and EINs, measuring a network's success at ecological imitation as representative of its sustainability. Studies have focused heavily on the number of links and nodes in a network, but have neglected the economic reality that each investment comes at the opportunity cost of all alternatives. This analysis focuses on the nestedness metric as used by ecologists to address this pivotal facet to the FW‐EIN analogy. Nestedness describes an ecological strategy for the position of links between nodes in a network in a way that maximizes network cycling for a given number of connections. This metric presents many advantages for EIN design and analysis, including maturity independence, size normalization, and a strong statistical record in highly mutualistic ecological systems. Application of nestedness to EINs indicates a lower presence of nested structures and more randomness than what is typically seen in FWs. The industrial networks also display a correlation between high nestedness and internal cycles, suggesting that the reuse of materials and energy in EINs can be improved upon by increasing the nestedness of structures.     

Levels of Institutional Capacity and Actor Expectations about Industrial Symbiosis

One assumption underlying the work on industrial symbiosis (IS) is that certain social conditions must be fulfilled in order for firms to develop symbiotic linkages. In this article we add depth to this insight by using institutional capacity as an underlying concept for these conditions, and we propose that such capacity influences IS by altering the opportunity set of actors. We then test the assumption on a dataset of 233 projects aiming to develop eco‐industrial parks. We find that the link between institutional capacity and the opportunities for symbiotic linkages perceived by actors is not always present and is more complicated than has been recognized thus far. We discuss potential alternative ways in which institutional capacity might influence IS and present ideas for future research to shed light on this important relationship.     

Scaling‐Up of Industrial Symbiosis in the Korean National Eco‐Industrial Park Program: Examining Its Evolution over the 10 Years between 2005–2014

In 2005, South Korea initiated the 15‐year National Eco‐Industrial Park Development Program in three stages to gradually transform aged industrial complexes into eco‐industrial parks (EIPs) by promoting industrial symbiosis (IS). Building upon the pilot experiences from the first 5 years, the second phase of the program focused on the scaling‐up of IS at a broader regional level. Key scaling‐up strategies included the expansion of target areas by connecting multiple industrial complexes, the standardization of processes and dissemination of learning, and the development of large‐scale projects that could contribute to the regional development. In this study, we examined the evolution of IS over the last 10 years between 2005 and 2014, primarily to understand the characteristics and impact of these scaling‐up strategies. Our findings showed that the scale of IS in the second phase had increased in various aspects in comparison to that in the first phase. The number of operating projects had increased from 52 to 159, the number of participating firms increased from 90 to 596, and the average distance of IS increased from 40 to 48 kilometers. The size of economic and environmental benefits also increased along with an increase in the private investment and government research funding. We further analyzed the role of the regional EIP centers as facilitators, how their activities influenced the scaling‐up of IS, and discussed the characteristics of the Korea's approach to IS.     

Social Semantic Web Framework for Industrial Synergies Initiation

Industrial synergies join two or more organizations that initially functioned as independent economic actors—that may originate from different sectors—together in order to share resources and exchange by‐products for mutual environmental, financial, and social benefits for its participants. Industrial symbioses (ISs) are networks of industrial synergies that can be initiated and created over time in various manners. In practice, the initiation of an industrial synergy, and particularly the identification of by‐product compatibilities, relies on direct or facilitated knowledge and information sharing, which is essential for discovering industrial synergy opportunities. Beyond its potential contribution to facilitate knowledge and information sharing among organizations, the Social Semantic Web (SSW) also has the potential to facilitate the initiation of industrial synergy by systematically and automatically identifying and recommending by‐products exchange compatibilities to potential partners. This framework exploits the ability of the sematic web to enable the search for analogies between potential partners within a region or district and existing industrial synergies around the world. This paper proposes the Social Semantic Web for Industrial Synergies Initiation (SSWISI) framework for the initiation of industrial synergies, which is based on the Social Semantic Web. The framework proposed in this paper adopts the concept of Linked Open Data (LOD), which enables the sharing and exchanging of information with external systems. This feature distinguishes the proposed framework from the existing approaches in its initiation of industrial synergies.     

Industrial Ecosystems and Food Webs: An Expansion and Update of Existing Data for Eco‐Industrial Parks and Understanding the Ecological Food Webs They Wish to Mimic

Cyclical industrial networks are becoming highly desirable for their efficient use of resources and capital. Progress toward this ideal can be enhanced by mimicking the structure of naturally sustainable ecological food webs (FWs). The structures of cyclic industrial networks, sometimes known as eco‐industrial parks (EIPs), are compared to FWs using a variety of important structural ecological parameters. This comparison uses a comprehensive data set of 144 FWs that provides a more ecologically correct understanding of how FWs are organized than previous efforts. In conjunction, an expanded data set of 48 EIPs gives new insights into similarities and differences between the two network types. The new information shows that, at best, current EIPs are most similar to those FWs that lack the components that create a biologically desirable cyclical structure. We propose that FWs collected from 1993 onward should be used in comparisons with EIPs, given that these networks are much more likely to include important network functions that directly affect the structure. We also propose that the metrics used in an ecological analysis of EIPs be calculated from an FW matrix, as opposed to a community matrix, which, to this point, has been widely used. These new insights into the design of ecologically inspired industrial networks clarify the path toward superior material and energy cycling for environmental and financial success.