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.     

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.     

Life cycle assessment of industrial symbiosis: A critical review of relevant reference scenarios

This paper highlights the methods and parameters used to define and design a reference scenario to be compared with an industrial symbiosis (IS) scenario using the life cycle assessment (LCA) methodology. To this end, a critical review was conducted of 26 peer‐reviewed papers using LCA in the field of IS. The analysis focuses on the definition and design of reference scenarios through five cross‐analyses to determine correlations between the type and the number of reference scenarios and the type of IS scenarios studied and also some LCA characteristics such as the functional unit, the type of data used, and the use of sensitivity analysis. Results show that the definition of reference scenarios depends mainly on the type of IS scenario considered. For a current IS developed at an industrial scale, the suitable reference scenario is mainly a hypothetical nonsymbiotic reference scenario. For a prospective IS, the suitable reference scenario is mainly a current nonsymbiotic reference scenario. Due to this critical review, the problem of variability of reference scenarios emerges. To resolve it, the authors analyze different reference scenarios or use sensitivity analysis. What is more, territorial aspects are rarely taken into account in the design of reference scenarios. It is clearly a gap for LCA of IS because of the influence of territorial factors. The new research challenge is to include the consideration of territorial aspects to define and design the worst‐ and best‐case reference scenarios to assess strict environmental performances of IS.     

Using an Industrial Waste Account to Facilitate National Level Industrial Symbioses by Uncovering the Waste Exchange Potential

The identification of potential by‐product exchanges is important for fostering industrial symbiosis. To discover these potential exchanges, this article extends the analysis of local industrial symbiosis to a national scale. A waste input‐output table, which is a material flow accounting tool, was compiled and used as a database to examine the existing exchanges of by‐products. The supplies and demands of industrial wastes or by‐products were compared to highlight their potential use for promoting higher exchange flows. The analysis of the linkages indicated that the majority of each of the by‐products were reused by the few industries that had the technology and operational capacity for reuse. This finding is useful for determining which industries are good candidates for promoting further industrial symbiosis (IS). Based on a nation‐wide analysis that considered the industrial characteristics of Taiwan comprehensively, 23 types of major by‐products with greater reuse flows and 216 potential exchange patterns were identified between the industries. In addition, three types of eco‐industrial networks were characterized as follows according to their dominant types: (1) fossil fuel, metal, and mineral‐dominated; (2) agricultural and synthetic material‐dominated; and (3) information and communications technology (ICT) and chemical industry‐dominated eco‐industrial networks. This analysis highlights the resource exchange potentials and provides information to new firms for networking with existing businesses.     

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.     

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.     

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.     

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.     

‘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.     

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.     

Measuring and Improving Eco‐efficiency Using Data Envelopment Analysis

The concept of eco‐efficiency can be defined with the “product value/environmental influence” ratio. Different models have been proposed to measure eco‐efficiency. The main difference among them is the weighting system used to aggregate the environmental results. Data envelopment analysis (DEA) permits this aggregation without requiring a subjective judgment about the weights. In this study, we applied a DEA model to Spanish Mahón‐Menorca cheese production to determine the most eco‐efficient production techniques. To this end, 16 scenarios of Mahón‐Menorca cheese production were built regarding technical (degree of automation) and cleaner production criteria. The environmental impacts were assessed by means of life cycle assessment. We carried out an economic assessment by determining the economic value added and the net income for each scenario. The results are referred to as 1 kilogram (kg) cheese ripened over 105 days. Through DEA, an eco‐efficiency ratio between 0 and 1 was obtained. Three scenarios were found to be eco‐efficient, with a high degree of automation (enclosed vat and molding and demolding machines) and accelerated cheese ripening. We used Monte Carlo simulation to carry out a sensitivity analysis to compare the influence of price changes on the eco‐efficiency ratio. The results emphasize the consistency and stability of the eco‐efficient scenarios.     

Modeling copper demand in China up to 2050: A business‐as‐usual scenario based on dynamic stock and flow analysis

In this paper, we develop a dynamic stock model and scenario analysis involving a bottom‐up approach to analyze copper demand in China from 2005 to 2050 based on government and related sectoral policies. The results show that in the short‐term, China's copper industry cannot achieve a completely circular economy without additional measures. Aggregate and per capita copper demand are both set to increase substantially, especially in infrastructure, transportation, and buildings. Between 2016 and 2050, total copper demand will increase almost threefold. Copper use in buildings will stabilize before 2050, but the copper stock in infrastructure and transportation will not yet have reached saturation in 2050. The continuous growth of copper stock implies that secondary copper will be able to cover just over 50% of demand in 2050, at best, even with an assumed recycling rate of 90%. Finally, future copper demand depends largely on the lifetime of applications. There is therefore an urgent need to prolong the service life of end‐use products to reduce the amount of materials used, especially in large‐scale applications in buildings and infrastructure.     

Industrial Wastes and By‐products as Alternative Fuels in Cement Plants: Evaluation of an Industrial Symbiosis Option

A ravenous fuel consumer, the cement industry may substitute fossil fuels by industrial wastes and by‐products, identifying the industry as a key example of industrial symbiosis (IS). Benefits from industrial waste alternative fuels (IWAFs) include safe disposal, fossil fuel cost savings, gate fees, and greenhouse gas credits. Poor IWAFs, (high moisture, ash and halogen content) bring higher gate fees, but lessen clinker production. Thermal rating and blower capacity constraints should be satisfied in such a case study of IS. Cement plants must comply with potentially tighter emission limits, compared to fossil fuel utilization, despite higher pollutant precursors in IWAFs. Emissions’ compliance, operational, and production implications are a few among several challenges when assessing multiple IWAF valorization as a symbiotic option from a systems’ perspective. A novel method is proposed to quantitatively assess critical trade‐offs. Species and energy transformations convey a rigorous picture of clinker level, kiln flue gas, and offgas volumes and lay the groundwork for screening, a priori selection, and process tuning. Necessary and sufficient compliance conditions and safety margins are presented in terms of process parameters and actual emissions’ data. Main challenges posed by high flue gas, high offgas volumes, high moisture, low heating value, increased nitrogen oxides emissions, and high halogen and metal content are quantified. As demonstrated in a case study of an actual 1.5 × 10⁶ tonnes per annum clinker plant in this paper, concurrent use of several IWAFs may increase clinker production, while satisfying operational constraints and maintaining compliance. The method may serve for devising IWAF preparation, or tuning mechanisms expanding IWAF valorization.     

Environmental Performance Analysis of Eco‐Industrial Parks in China: A Data Envelopment Analysis Approach

In pursuit of more sustainable development of industry, China has been actively developing eco‐industrial parks (EIPs) for more than a decade. However, the environmental value of these EIPs remains largely unverified. This study aimed to evaluate the environmental performance of national EIPs in China using data envelopment analysis. Eco‐efficiency and environmental performance indices were used to represent the static and dynamic environmental performance of EIPs, respectively. An environmental performance index was formed by combining measures of eco‐efficiency in a dynamic setting with the sequential Malmquist index approach. We obtained three main empirical findings. First, 34 national EIPs exhibited a cumulative environmental performance improvement of 89.4% from 2007 to 2010, which is primarily the result of eco‐efficiency change rather than environmental technical change. Second, compared with the trial EIPs, the demonstration EIPs had a higher average eco‐efficiency (0.611 vs. 0.446 in 2010) and experienced greater average environmental performance improvement (129% vs. 60%). Third, the EIPs retrofitted from high‐tech industrial development zones exhibited much higher average eco‐efficiency (0.798 vs. 0.440 in 2010) than those retrofitted from economic and technical development zones. The key measures supporting the performance improvement and policy implications for the development of EIPs are also discussed.     

“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.     

Analyzing the Environmental Benefits of Industrial Symbiosis

Studies of industrial symbiosis (IS) focus on the physical flows of materials and energy in local industrial systems. In an ideal IS, waste material and energy are shared or exchanged among the actors of the system, thereby reducing the consumption of virgin material and energy inputs, and likewise the generation of waste and emissions. In this study, the environmental impacts of an industrial ecosystem centered around a pulp and paper mill and operating as an IS are analyzed using life cycle assessment (LCA). The system is compared with two hypothetical reference systems in which the actors would operate in isolation. Moreover, the system is analyzed further in order to identify possibilities for additional links between the actors. The results show that of the total life cycle impacts of the system, upstream processes made the greatest overall contribution to the results. Comparison with stand‐alone production shows that in the case studied, the industrial symbiosis results in modest improvements, 5% to 20% in most impact categories, in the overall environmental impacts of the system. Most of the benefits occur upstream through heat and electricity production for the local town. All in all it is recommended that when the environmental impacts of industrial symbiosis are assessed, the impacts occurring upstream should also be studied, not only the impacts within the ecosystem.     

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.     

Ecological network analysis of urban–industrial ecosystems

Sustainability of urban areas is paramount in the coming years as cities continue to grow in population and resource consumption. A number of methods to model cities have been developed, including material flow analysis and urban metabolism, but these accounting methods do not fully analyze the complex network dynamics present within cities. Ecological network analysis (ENA) provides a new perspective into these urban areas by using metrics designed for analysis of natural ecosystems. This study analyzes 29 urban–industrial ecosystems using ENA, comparing the networks to each other as well as comparing them to previously analyzed eco‐industrial parks and natural food webs. It is found that these systems perform similar to other human‐designed systems, which consistently lack in ecological performance when compared with the natural ecosystems. Additionally, the impact of specific actor types within these networks is shown indicating the importance of industry, agriculture, and the natural environment. Finally, the types of networks are determined to affect the ecological metrics, with the more linear‐based energy networks having the worst performance. This new dataset of ecologically analyzed networks provides a deeper understanding of urban networks and their infrastructure, while providing useful information on how to potentially improve their sustainability.     

长江经济带典型锌冶炼园区不同固废处置模式生态效率研究

我国铜铅锌有色冶炼固废种类多、存量大,富含多种环境毒害元素如镉铬汞砷等,而目前固废末端处置方式单一,对其所含的大量铜铅锌银镍等有价金属组分也未能有效分离,固废污染防控与高效资源化利用问题突出,已成为制约产业绿色可持续发展的关键因素。以长江经济带典型铜铅锌综合冶炼基地为例,设置直接处理(情景1)、内部循环(情景2)和协同利用(情景3)三种锌冶炼固废处置情景模式,结合物质投入产出法、层次分析法与熵值法,构建资源能耗、环境风险、物质循环与经济效益的多维生态效率指标核算方法体系,对三种情景模式开展生态效率综合评估分析。结果表明,情景3因加强了锌冶炼固废在铜、铅冶炼系统间的协同转化,其生态效率综合评价指数最高,为0.2246,较情景1和情景2分别高出313.6%和25.5%;从资源能耗角度来看,情景2单位产品能耗最高,达0.3086;而从物质循环和经济效益角度来看,情景3固废综合利用率最高,达97.6%,铜铅锌三种有价金属回收率达97.2%,利润总额达48131.3万元;但在环境风险方面,尽管情景3固废中重金属污染排放减少1470.4 t/a,但废气中铅砷镉汞等重金属污染排放却比情景1增加了3倍...     

Redefining Industrial Symbiosis

The most commonly cited definition of industrial symbiosis (IS), by Chertow (2000) , has served well to foster discussion and research for more than a decade. The definition reflected the state of research and practice at the time; as both have advanced, some terms have been interpreted in substantially different ways. In this article we analyze those generally used terms for their connection to the ecological metaphor that is the root of industrial ecology, and their varied interpretations in IS research and practice over time. We then propose an updated definition intended to communicate the essence of IS as a tool for innovative green growth: IS engages diverse organizations in a network to foster eco‐innovation and long‐term culture change. Creating and sharing knowledge through the network yields mutually profitable transactions for novel sourcing of required inputs and value‐added destinations for non‐product outputs, as well as improved business and technical processes. We posit that, although geographic proximity is often associated with IS, it is neither necessary nor sufficient—nor is a singular focus on physical resource exchange.