Allocation of environmental burdens in co-product systems: Process and product-related burdens (part 2)

ISO 14041 requires that allocation by physical causality must reflect the quantitative changes in product outputs or functions and will not necessarily be in proportion to simple physical measure such as mass. This paper examines the instances where physical causality can be represented by mass. However, it also goes further than ISO to demonstrate that the type of causality in the system is not necessarily always the same and can change depending on the way the system is operated. Whole system modelling and the marginal allocation approach are used to identify the correct type of causality for different operating states of the system and the corresponding changes in the environmental burdens. This is generally not possible with the other allocation methods, also examined in this paper. Both process- and product-related burdens are considered and the approach is illustrated by a reference to an existing system producing five boron co-products     

Life Cycle Assessment of a Magazine,Part II: A Comparison of Print and Tablet Editions

The rapid development of information and communications technology (ICT) is providing new ways to access media content. Electronic media are sometimes more advantageous from an environmental perspective than paper‐based media solutions, but ICT‐based media can also bring environmental burdens. This study compared the potential environmental impacts in a life cycle perspective of a print edition of a magazine and that of its electronic edition read on a tablet device. Important objectives were to identify activities giving rise to the main environmental impacts for both the print and tablet editions, determine the key factors influencing these impacts, and address data gaps and uncertainties. A detailed assessment of the tablet edition is provided in a previous article (part 1), whereas this article compares it with the print edition. The methodology used was life cycle assessment and the environmental impacts assessed included climate change, cumulative energy/exergy demand, metal depletion, photochemical oxidant formation, particulate matter formation, terrestrial acidification, freshwater eutrophication, marine eutrophication, and fossil depletion. Use of different functional units to compare the print and tablet editions of the magazine resulted in different relative environmental impacts. In addition, emerging (low number of readers and low reading time per copy) and mature (higher number of readers and higher reading time per copy) tablet editions yielded varying results. The emerging tablet edition resulted in higher potential environmental impacts per reader than the print edition, but the mature tablet edition yielded lower impacts per reader in half the impact categories assessed. This illustrates the importance of spreading the environmental impacts over a large number of readers. The electricity mix used in product system processes did not greatly affect the results of tablet/print comparisons, but overall number of readers for the tablet edition, number of readers per copy for the print edition, file size, and degree of use of the tablet device proved crucial for the comparison results.     

Environmental assessment of brownfield rehabilitation using two different life cycle inventory models

Goal, Scope and Background The primary goal of this paper is to present a LCI modelling approach that allows the inclusion of all three types of impacts. The approach is based on consequential LCA (CLCA) rather than more common attributional LCA (ALCA). In CLCA, system boundaries are expanded in order to include all significantly affected activities. In addition we show how changing from an attributional to a consequential approach alters how the impacts are evaluated, and discuss the applicability of these two distinct approaches to brownfield rehabilitation decision support. The paper is restricted to urban and contaminated brownfields that are the result of industrial use and whose rehabilitation is aimed at allowing residential redevelopment. Main Features The approach is based on an analogy between the open-loop recycling of material resources and brownfield rehabilitation. Brownfield rehabilitation is associated with two functions: (1) managing the legacy of past occupations on the site, analogous to a waste management function, and (2) providing redevelopable land, analogous to a commodity production function. The consequential system is expanded to cover the subsequent occupation life cycle of the brownfield and the effects on the occupation life cycles of other sites. The proposed model quantifies effects on sites competing to supply the same occupation function. Two approaches are proposed to determine the nature of the sites that are affected and to what extent they are affected: the first resembling a closed-loop approximation, and the second based on economic partial-equilibrium models. Results and Conclusions The scope of the CLCA is far more complex than that of the ALCA. It requires additional data that are associated with important sources of uncertainty. It does allow, however, for the inclusion of tertiary impacts, making it suitable for the evaluation of the often cited environmental benefits of reintegrating the site in the economy. In addition, the ALCA methodology seems to be inappropriate to compare brownfield management options that result in different subsequent uses of the site. Since the effects of this fate are included within the scope of CLCA, however, virtually any brownfield management option available to a decision-maker can aptly be compared. The evaluation of primary and secondary impacts also differs when the consequential approach is used rather than the attributional approach. It is impossible to anticipate the effects of these methodological differences on the results based on the qualitative discussion presented in this paper. Perspectives The complexity and uncertainty introduced by switching to a consequential approach is very high: it is therefore recommendable to evaluate the significance in the gain of environmental information in an actual case study to determine if system expansion is recommendable. Such a case study is presented in Part II to this paper. [39] Lesage P, Ekvall T, Deschênes L, Samson R (20006): Environmental Assessment of Brownfield Rehabilitation Using Two Different Life Cycle Inventory Models. Part 2: Case Study. Int J LCA, OnlineFirst (DOI: )     

Environmental assessment of yield improvements obtained by the use of the enzyme phospholipase in mozzarella cheese production

Background, aim and scope  Phospholipase is an enzyme which is able to increase the yield of cheese in, for instance, mozzarella production. Milk production is the most important source of environmental impacts in cheese production and it is obvious to assume that the milk saving that comes with the use of phospholipase reduces the overall environmental impacts of the final product. Production of industrial phospholipase is, however, also associated with environmental burdens and it is not known whether and to what extent the use of phospholipase is justified by overall environmental improvements. The aim of the present study is therefore to assess the environmental impacts that come with the use of industrial phospholipase in mozzarella production and compare with the savings that come with the avoided milk production. The study addresses mozzarella production in Denmark. Methods  LCA is used as analytical tool and environmental modelling is facilitated in SimaPro 7.1.8 LCA software. Yield improvements refer to full scale industrial application of phospholipase in cheese industry. The study is a comparative analysis and a marginal and market-oriented approach is taken. The study addresses contribution to global warming, acidification, nutrient enrichment, photochemical smog formation, energy consumption and use of agricultural land. Estimation of environmental impact potentials is based on Eco-indicator 95 v.2.1 equivalency factors. Toxicity is addressed by qualitative means. Results  The environmental impacts induced by phospholipase production are small compared with the savings obtained by reduced milk consumption for mozzarella production when all impact indicators are considered. Sensitivity analyses and data quality assessments indicate that this general outcome of the study is robust, although results at the more detailed level are the subject of much variation and uncertainty. Discussion  Transport of the enzyme from producer to mozzarella producer is insignificant and the general outcome of the study is considered applicable to other regions of the world where milk is produced in modern milk production systems. Conclusions  Use of phospholipase as a yield improvement factor is a means of reducing environmental impact of mozzarella production. Recommendations and perspectives  The total annual global warming mitigation potential of phospholipase used in production of mozzarella and other pasta filata products is in the order of 7 × 10⁸ kg CO₂ equivalents. The use of phospholipase is driven by overall cost savings and it is therefore recommended that the enzyme should be given attention as a cost-efficient means of reducing greenhouse gas emissions.     

Life cycle assessment of chemical agent resistant coatings

The Department of Defense (DoD) and the U.S. Environmental Protection Agency (EPA) have established a history of cooperation on a wide variety of pollution prevention research efforts, which apply the principles of Life-Cycle Engineering and Design (LCED) to DoD operations. DoD and EPA jointly sponsored this project, with funding from EPA and DoD’s Strategic Environmental Research and Development Program (SERDP), to focus on using Life Cycle Assessment (LCA) principles for optimizing the process of painting military vehicles with chemical agent resistant coatings (CARC). The objectives were to identify environmental and energy burdens of the CARC painting life cycle, and to identify and test potential improvements on a life cycle basis. This LCA of CARC includes difficulties and lessons learned while conducting all three LCA components. The streamlined life-cycle inventory (LCI) involved quantification of environmental and energy burdens associated with the CARC life cycle. Based on the results of the LCI, a preliminary scoping of potential impacts, and a knowledge of alternative CARC painting materials and equipment, five alternatives for the application of CARC were identified. The life-cycle impact assessment (LCIA) of these applications used the equivalency method for impact characterization. The life-cycle improvement assessment (LCImA) results suggested that one application, based on combining an alternative primer and the turbine high-velocity, low-pressure (HVLP) spray painting system, should be subjected to test and evaluation. The LCIA gave this alternative the lowest environmental impact potential scores for seven of nine impact categories compared to the five other alternative systems evaluated. The preferred alternative was technically evaluated in the laboratory against the baseline CARC system using test panels painted at two Army bases. Preliminary results indicate that the preferred alternative performs equal or better than the baseline system at lower cost and with reduced environmental impact potential.     

Evaluation of Life Cycle Assessment Recycling Allocation Methods

Life cycle assessment practitioners struggle to accurately allocate environmental burdens of metals recycling, including the temporal dimension of environmental impacts. We analyze four approaches for calculating aluminum greenhouse gas emissions: the recycled content (RC) or cut‐off approach, which assumes that demand for recycled content displaces primary production; end‐of‐life recycling (EOLR), which assumes that postuse recycling displaces primary production; market‐based (MB) approaches, which estimate changes in supply and demand using price elasticities; and value‐corrected substitution (VCS), which allocates impact based on price differences between primary and recycled material. Our analysis suggests that applications of the VCS approach do not adequately account for the changing scrap to virgin material price ratio over time, whereas MB approaches do not address stock accumulation and depletion. The EOLR and RC approaches were analyzed using two case studies: U.S. aluminum beverage cans and vehicle engine blocks. These approaches produced similar results for beverage cans, which have a closed material loop system and a short product life. With longer product lifetimes, as noted with the engine blocks, the magnitude and timing of the emissions differs greatly between the RC and EOLR approaches. The EOLR approach indicates increased impacts at the time of production, offset by negative impacts in future years, whereas the RC approach assumes benefits to increased recycled content at the time of production. For vehicle engine blocks, emissions using EOLR are 140% higher than with RC. Results are highly sensitive to recycled content and future recycling rates, and the choice of allocation methods can have significant implications for life cycle studies.     

Life cycle assessment of 3D printing geo‐polymer concrete: An ex‐ante study

Three‐dimensional (3D) printing and geo‐polymers are two environmentally oriented innovations in concrete manufacturing. The 3D printing of concrete components aims to reduce raw material consumption and waste generation. Geo‐polymer is being developed to replace ordinary Portland cement and reduce the carbon footprint of the binder in the concrete. The environmental performance of the combined use of the two innovations is evaluated through an ex‐ante life cycle assessment (LCA). First, an attributional LCA was implemented, using data collected from the manufacturer to identify the hotspots for environmental improvements. Then, scaled‐up scenarios were built in collaboration with the company stakeholder. These scenarios were compared with the existing production system to understand the potential advantages/disadvantages of the innovative system and to identify the potential directions for improvement. The results indicate that 3D printing can potentially lead to waste reduction. However, depending on its recipe, geo‐polymer likely has higher environmental impacts than ordinary concrete. The ex‐ante LCA suggests that after step‐by‐step improvements in the production and transportation of raw materials, 3D printing geo‐polymer concrete is able to reduce the carbon footprint of concrete components, while it does still perform worse on impact categories, such as depletion of abiotic resources and stratospheric ozone depletion. We found that the most effective way to lower the environmental impacts of 3D concrete is to reduce silicate in the recipe of the geo‐polymer. This approach is, however, challenging to realize by the company due to the locked‐in effect of the previous innovation investment. The case study shows that to support technological innovation ex‐ante LCA has to be implemented as early as possible in innovation to allow for maintaining technical flexibility and improving on the identified hotspots.     

Towards Productive Cities: Environmental Assessment of the Food‐Energy‐Water Nexus of the Urban Roof Mosaic

Cities are rapidly growing and need to look for ways to optimize resource consumption. Metropolises are especially vulnerable in three main systems, often referred to as the FEW (i.e., food, energy, and water) nexus. In this context, urban rooftops are underutilized areas that might be used for the production of these resources. We developed the Roof Mosaic approach, which combines life cycle assessment with two rooftop guidelines, to analyze the technical feasibility and environmental implications of producing food and energy, and harvesting rainwater on rooftops through different combinations at different scales. To illustrate, we apply the Roof Mosaic approach to a densely populated neighborhood in a Mediterranean city. The building‐scale results show that integrating rainwater harvesting and food production would avoid relatively insignificant emissions (13.9–18.6 kg CO₂ eq/inhabitant/year) in the use stage, but their construction would have low environmental impacts. In contrast, the application of energy systems (photovoltaic or solar thermal systems) combined with rainwater harvesting could potentially avoid higher CO₂ eq emissions (177–196 kg CO₂ eq/inhabitant/year) but generate higher environmental burdens in the construction phase. When applied at the neighborhood scale, the approach can be optimized to meet between 7% and 50% of FEW demands and avoid up to 157 tons CO₂ eq/year. This approach is a useful guide to optimize the FEW nexus providing a range of options for the exploitation of rooftops at the local scale, which can aid cities in becoming self‐sufficient, optimizing resources, and reducing CO₂ eq emissions.     

Application of LCA as a decision-making tool for waste management systems

Aim, Scope and Background  When materials are recycled they are made available for use for several future life cycles and can therefore replace virgin material more than just once. In order to analyse the optimal waste management system for a given material, the authors have analysed the material flows in a life cycle perspective. It is important to distinguish this approach for material flow analysis for a given material from life cycle analysis of products. A product life cycle analysis analyses the product system from cradle to grave, but uses some form of allocation in order to separate the life cycle of one product from another in cases where component materials are recycled. This paper does not address allocation of burdens between different product systems, but rather focuses on methodology for decision making for waste management systems where the optimal waste management system for a given material is analysed. The focus here is the flow of the given material from cradle (raw material extraction) to grave (the material, or its inherent energy, is no longer available for use). The limitation on the number of times materials can be recycled is set by either the recycling rate, or the technical properties of the recycled material. Main Features  This article describes a mathematical geometric progression approach that can be used to expand the system boundaries and allow for recycling a given number of times. Case studies for polyethylene and paperboard are used to illustrate the importance of including these aspects when part of the Goal and Scope for the LCA study is to identify which waste management treatment options are best for a given material. The results and discussion examine the different conclusions that can be reached about which waste management option is most environmentally beneficial when the higher burdens and benefits of recycling several times are taken into account. Results  In order to assess the complete picture of the burdens and benefits arising from recycling the system boundaries must be expanded to allow for recycling many times. A mathematical geometric progression approach manages to take into account the higher burdens and benefits arising from recycling several times. If one compares different waste management systems, e.g. energy recovery with recycling, without expanding the system to include the complete effects of material recycling one can reach a different conclusion about which waste management option is preferred. Conclusions  When the purpose of the study is to compare different waste management options, it is important that the system boundaries are expanded in order to include several recycling loops where this is a physical reality. The equations given in this article can be used to include these recycling loops. The error introduced by not expanding the system boundaries can be significant. This error can be large enough to change the conclusions of a comparative study, such that material recycling followed by incineration is a much better option than waste incineration directly. Recommendations and Outlook  When comparing waste management solutions, where material recycling is a feasible option, it is important to include the relevant number of recycling loops to ensure that the benefits of material recycling are not underestimated. The methodology presented in this article should be used in future comparative studies for strategic decision-making for waste management. The approach should not be used for LCAs for product systems without due care, as this could lead to double counting of the benefits of recycling (depending on the goal and scope of the analysis). For materials where the material cycle is more of a closed loop and one cannot truly say that recycled materials replace virgin materials, a more sophisticated approach will be required, taking into account the fact that recycled materials will only replace a certain proportion of virgin materials.     

Comparative LCAs for Curbside Recycling Versus Either Landfilling or Incineration with Energy Recovery (12 pp)

Background This article describes two projects conducted recently by Sound Resource Management (SRMG) – one for the San Luis Obispo County Integrated Waste Management Authority (SLO IWMA) and the other for the Washington State Department of Ecology (WA Ecology). For both projects we used life cycle assessment (LCA) techniques to evaluate the environmental burdens associated with collection and management of municipal solid waste. Both projects compared environmental burdens from curbside collection for recycling, processing, and market shipment of recyclable materials picked up from households and/or businesses against environmental burdens from curbside collection and disposal of mixed solid waste. Method logy. The SLO IWMA project compared curbside recycling for households and businesses against curbside collection of mixed refuse for deposition in a landfill where landfill gas is collected and used for energy generation. The WA Ecology project compared residential curbside recycling in three regions of Washington State against the collection and deposition of those same materials in landfills where landfill gas is collected and flared. In the fourth Washington region (the urban east encompassing Spokane) the WA Ecology project compared curbside recycling against collection and deposition in a wasteto- energy (WTE) combustion facility used to generate electricity for sale on the regional energy grid. During the time period covered by the SLO study, households and businesses used either one or two containers, depending on the collection company, to separate and set out materials for recycling in San Luis Obispo County. During the time of the WA study households used either two or three containers for the residential curbside recycling programs surveyed for that study. Typically participants in collection programs requiring separation of materials into more than one container used one of the containers to separate at least glass bottles and jars from other recyclable materials. For the WA Ecology project SRMG used life cycle inventory (LCI) techniques to estimate atmospheric emissions of ten pollutants, waterborne emissions of seventeen pollutants, and emissions of industrial solid waste, as well as total energy consumption, associated with curbside recycling and disposal methods for managing municipal solid waste. Emissions estimates came from the Decision Support Tool (DST) developed for assessing the cost and environmental burdens of integrated solid waste management strategies by North Carolina State University (NCSU) in conjunction with Research Triangle Institute (RTI) and the US Environmental Protection Agency (US EPA)1. RTI used the DST to estimate environmental emissions during the life cycle of products. RTI provided those estimates to SRMG for analysis in the WA Ecology project2. For the SLO IWMA project SRMG also used LCI techniques and data from the Municipal Solid Waste Life- Cycle Database (Database), prepared by RTI with the support of US EPA during DST model development, to estimate environmental emissions from solid waste management practices3. Once we developed the LCI data for each project, SRMG then prepared a life cycle environmental impacts assessment of the environmental burdens associated with these emissions using the Environmental Problems approach discussed in the methodology section of this article. Finally, for the WA study we also developed estimates of the economic costs of certain environmental impacts in order to assess whether recycling was cost effective from a societal point of view. Conclusions Recycling of newspaper, cardboard, mixed paper, glass bottles and jars, aluminum cans, tin-plated steel cans, plastic bottles, and other conventionally recoverable materials found in household and business municipal solid wastes consumes less energy and imposes lower environmental burdens than disposal of solid waste materials via landfilling or incineration, even after accounting for energy that may be recovered from waste materials at either type disposal facility. This result holds for a variety of environmental impacts, including global warming, acidification, eutrophication, disability adjusted life year (DALY) losses from emission of criteria air pollutants, human toxicity and ecological toxicity. The basic reason for this conclusion is that energy conservation and pollution prevention engendered by using recycled rather than virgin materials as feedstocks for manufacturing new products tends to be an order of magnitude greater than the additional energy and environmental burdens imposed by curbside collection trucks, recycled material processing facilities, and transportation of processed recyclables to end-use markets. Furthermore, the energy grid offsets and associated reductions in environmental burdens yielded by generation of energy from landfill gas or from waste combustion are substantially smaller then the upstream energy and pollution offsets attained by manufacturing products with processed recyclables, even after accounting for energy usage and pollutant emissions during collection, processing and transportation to end-use markets for recycled materials. The analysis that leads to this conclusion included a direct comparison of the collection for recycling versus collection for disposal of the same quantity and composition of materials handled through existing curbside recycling programs in Washington State. This comparison provides a better approximation to marginal energy usage and environmental burdens of recycling versus disposal for recyclable materials in solid waste than does a comparison of the energy and environmental impacts of recycling versus management methods for handling typical mixed refuse, where that refuse includes organics and non-recyclables in addition to whatever recyclable materials may remain in the garbage. Finally, the analysis also suggests that, under reasonable assumptions regarding the economic cost of impacts from pollutant emissions, the societal benefits of recycling outweigh its costs.     

Life Cycle assessment of bio-ethanol derived from cellulose

Objective, Scope, Background  A comprehensive Life Cycle Assessment was conducted on bio-ethanol produced using a new process that converts cellulosic biomass by enzymatic hydrolysis. Options for sourcing the feedstock either from agricultural and wood waste, or, if the demand for bio-ethanol is sufficient, from cultivation are examined. The main focus of the analysis was to determine its potential for reducing greenhouse gas emissions in a 10% blend of this bio-ethanol with gasoline (E10) as a transportation fuel. Methods  SimaPro 4.0 was used as the analysis tool, which allowed a range of other environmental impacts also to be examined to assess the overall relative performance to gasoline alone. All impacts were assigned to the fuel because of uncertainties in markets for the by-products. This LCA therefore represents a worst case scenario. Results, Conclusion  It is shown that E10 gives an improved environmental performance in some impact categories, including greenhouse gas emissions, but has inferior performances in others. Whether the potential benefits of the bio-ethanol blend to reduce greenhouse gas emissions will be realized is shown to be particularly sensitive to the source of energy used to produce the process steam required to break down the cellulose to produce sugars and to distil the final product. One key area where improvements in environmental performance might be derived is in enzyme production. Recommendations and Outlook  The LCA profile helps to highlight those areas where positive and negative environmental impacts can be expected. Technological innovation can be directed accordingly to preserve the benefits while minimizing the negative impacts as development progresses to commercial scales.     

Electrical and electronic components in the automotive sector: Economic and environmental assessment

Background Aims and Scope Automotive electrical and electronic systems (EES) comprise an area that has grown steadily in importance in the past decade and will continue to gain relevance in the foreseeable future. For this reason, the SEES project (Sustainable Electrical & Electronic System for the Automotive Sector) aims to contribute to cost-effective and eco-efficient EES components. Scenarios for the recovery of automotive EES are defined by taking into consideration the required improvements in EES design and the development and implementation of new technologies. The research project SEES is funded by the European Commission (Contract no. TST3-CT-2003-506075) within the Sixth Framework Programme, priority 6.2 (see 〈www.sees-project.net〉 for more information). This paper presents the findings of an assessment of the environmental and economic improvements for automotive EES from a system perspective, taking into account all life cycle steps. Methods Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) case studies have been employed within the SEES project to define optimum design and end-of-life scenarios. These case studies have been applied to two selected EES components: an engine wire harness and a smart junction box, both manufactured by LEAR and assembled in an existing Ford car model. The component design has a significant impact on the product system and its processes, including its use and end-of-life (EOL) phase. For each of the analysed components, two potential design alternatives have been compared with the original design, based on designers’ recommendations from the status quo scenario results. These include the use of alternative wiring systems with a reduced copper content (flat flexible cable), lead-free solder alloys and new fixation mechanisms to facilitate disassembly. The overall EOL scenario determines the technologies of processes that must be modelled within the EOL phase of a product system. The analysed end-of-life scenarios include: status quo car recycling and two alternatives: 1. disassembly for specific EES component recycling; 2. advanced post-shredder recycling of shredding residues. The influences of the different design and EOL treatment scenarios on the LCA and LCC results have been analysed. Results The most dominant life cycle phases for the LCA results are manufacturing (including raw material extraction and manufacturing of materials and components) and the use-phase. Similarly, manufacturing was the predominant phase during the LCC study. Disassembly costs were shown to be significant during the EOL phase. Among the analysed design alternatives, the highest environmental improvement potential were gained from the use of alternative wiring systems with reduced weight and copper content, but with slightly increased life cycle costs. Smaller differences of the results were determined for the different end-of-life scenarios. Discussion The results of the EOL scenario depend on the component in question. The influence of variations in process data, model choices, e.g. which LCIA model was used for calculating the Human Toxicity Potential (HTP), which inventory data for copper production was used and other variables have been assessed in the sensitivity analysis. The sensitivity analysis demonstrates a strong dependency of results for HTP on the selected model. The presented results are based on a public report of the SEES project. The study has undergone a critical review by an external expert according to ISO 14040, § 7.3.2. Conclusions The environmental impacts during the life cycle of the analysed products are generally most strongly influenced by material production and the use phase of the products. In comparison, improvements during the EOL phase have only a very limited potential to reduce environmental impacts. The studied design changes displayed clear environmental advantages for (lighter) flat, flexible cables. Whereas, the lead-free solder design alternatives showed a slight increase in some environmental impact categories. The application of these design changes has been limited in some cases by technical issues. Recommendations and Perspectives Focussing only on end-of-life improvements cannot be recommended for automotive EES products. A life-cycle perspective should be utilised for assessing improvements in individual life cycle stages of a product. The presented results will be an input for Eco-design guidelines for automotive EES, to be developed at a later stage within the SEES project. ESS-Submission Editor: Dr. Lester Lave (II01@andrew.cmu.edu)     

Life cycle assessment study of color computer monitor

The environmental performance of a color computer monitor is investigated by implementing a Life Cycle Assessment. The goal of this study is to collect LCI data of foreground systems, to identify hot spots, and to introduce life cycle thinking at the product design stage. Secondary data are used in the background system, and site-specific data are collected in the foreground system. Results show that the use phase is the most contributing phase. The operating mode and the energy saving mode during the overall use phase contribute to the total by 59% and by 9.9%, respectively. In the production phase, the cathode ray tube assembly process and the printed circuit board assembly process are the most contributing processes. The sensitivity analysis on the use pattern scenario shows that the contribution ratio of the use phase ranges from 32% to 84%. Even in the home use case, which is the best case scenario, the use phase is one of the most contributing processes to the environmental performance of the color computer monitor. There is no significant difference in the choice of the impact assessment methodologies for identifying the improvement opportunities. For the external use of Life Cycle Assessment in a short-run product for the market, it is recommended that Life Cycle Assessment should be carried out in parallel with the product design stage. It is also necessary to have a pre-existing, in-house database for a product group in order to accelerate life cycle procedures.     

Combined Use of Life Cycle Assessment and Groundwater Transport Modeling to Support Contaminated Site Management

The subject of this study is a spent pot lining (SPL) landfill. The aim of this study was to identify the site remediation option, among four alternatives, that minimizes overall environmental impacts based on: 1) a comparative life cycle assessment (LCA); and 2) modeling of contaminant transport in groundwater. The four options were: leaving the landfill in place (Option 1); excavation of the landfill, with on-site disposal of the excavated materials in a secure cell (Option 2); excavation of the landfill, with treatment of the SPL fraction (Option 3); and excavation of the landfill, with incineration of the SPL fraction in a cement kiln (Option 4). The LCA was performed following the guidelines provided by the International Standard Organization (ISO). Furthermore, to improve the relevance of LCA to site remediation sector, impacts caused by residual in-situ contamination were assessed by applying a simulation of contaminant transport in groundwater, using site-specific data. The LCA identified Option 1 as having the least environmental impacts. However, the transport modeling concluded that contaminant concentrations 50 years from the present could be approximately 30 to 40 times the regulatory criteria if this option is retained. In addition, this study demonstrated that LCA can be used as a screening tool to help identify significant environmental issues; the LCA identified acute and chronic water ecotoxicity categories as being the dominant impact categories of the environmental profile and consequently, it is recommended that a complete environmental risk assessment (ERA) be performed for Option 1.     

A Life Cycle Assessment on the Dehairing of Rawhides: Chemical Treatment versus Enzymatic Recovery through Solid State Fermentation

The leather industry needs to switch from the traditional chemically based dehairing process to an environmentally friendly one so that the overall burdens to the environment are reduced. The primary goal of the work was thus to compare the chemical leather dehairing process to an enzymatically based one using the enzymes that are extracted after the application of solid state fermentation (SSF) on hair wastes generated after dehairing. The environmental burdens of the dehairing stage were determined using a life cycle assessment (LCA) approach by comparing the two aforementioned management scenarios. The first scenario was the commonly used technology in which hair is removed via a chemical process and then composted in open piles. This scenario included two subscenarios where hair waste is either incinerated or landfilled. In the second scenario, the proteolytic enzymes extracted during the SSF of the residual hair are used to dehair the new rawhides instead of chemicals. Industrial and laboratory data were combined with international databases using the SimaPro 8.0 LCA software to make comparisons. The environmental impacts associated with the enzymatic dehairing were significantly lower than the ones associated to the conventional chemical dehairing process. This difference is attributed to the impacts associated with the original production of the chemicals and to the electricity consumed in the conventional method. A sensitivity analysis revealed that the results are affected by the amounts of chemicals used during dehairing.     

Ecosystem Services in Life Cycle Assessment while Encouraging Techno‐Ecological Synergies

Life cycle assessment (LCA) has enabled consideration of environmental impacts beyond the narrow boundary of traditional engineering methods. This reduces the chance of shifting impacts outside the system boundary. However, sustainability also requires that supporting ecosystems are not adversely affected and remain capable of providing goods and services for supporting human activities. Conventional LCA does not account for this role of nature, and its metrics are best for comparing alternatives. These relative metrics do not provide information about absolute environmental sustainability, which requires comparison between the demand and supply of ecosystem services (ES). Techno‐ecological synergy (TES) is a framework to account for ES, and has been demonstrated by application to systems such as buildings and manufacturing activities that have narrow system boundaries. This article develops an approach for techno‐ecological synergy in life cycle assessment (TES‐LCA) by expanding the steps in conventional LCA to incorporate the demand and supply of ecosystem goods and services at multiple spatial scales. This enables calculation of absolute environmental sustainability metrics, and helps identify opportunities for improving a life cycle not just by reducing impacts, but also by restoring and protecting ecosystems. TES‐LCA of a biofuel life cycle demonstrates this approach by considering the ES of carbon sequestration, air quality regulation, and water provisioning. Results show that for the carbon sequestration ecosystem service, farming can be locally sustainable but unsustainable at the global or serviceshed scale. Air quality regulation is unsustainable at all scales, while water provisioning is sustainable at all scales for this study in the eastern part of the United States.     

The environmental impacts of operating an Antarctic research station

We present a life cycle assessment (LCA) of the operation of Casey Station in Antarctica. The LCA included quantifying material and energy flows, modeling of elementary flows, and subsequent environmental impacts. Environmental impacts were dominated by emissions associated with freight operations and electricity cogeneration. A participatory design approach was used to identify options to reduce environmental impacts, which included improving freight efficiency, reducing the temperature setpoint of the living quarters, and installing alternative energy systems. These options were then assessed using LCA, and have the potential to reduce environmental impacts by between 2% and 19.1%, depending on the environmental indicator.     

The Role of Washing Machines in Life Cycle Assessment Studies

A key requirement for those in industry and elsewhere who wish to reduce the environmental impact of a product is to develop priorities for action. Life cycle assessment (LCA) is increasingly used to identify such priorities but can be misleading. This article draws attention to two effects that can occur when the system boundary for a product LCA is not defined correctly. We illustrate the "washing machine effect" by showing that in separate life cycle studies of clothing, detergents, and washing machines, the use of energy is dominated by operation of the washing machine. All three studies prioritize the use phase for action, but in an aggregated study, double counting of the use-phase impact occurs. We demonstrate the "inverse washing machine effect" with an example related to energy used in transport. We show that some activities that are significant on a cumulative basis consistently fall outside the chosen system boundary for individual products. A consequence is that when LCA studies are used for prioritization, they are in danger of overemphasizing the use-phase impacts and overlooking the impacts from indirect activities. These effects, which are broadly understood by LCA developers, appear not to be understood properly by those who use LCA to direct priorities for action. Therefore, practitioners should be wary of using LCA for prioritizing action, and LCA guidance documents should reflect this caution.     

The Environmental Importance of Energy Use in Chemical Production

In many cases, policy makers and laymen perceive harmful emissions from chemical plants as the most important source of environmental impacts in chemical production. As a result, regulations and environmental efforts have tended to focus on this area. Concerns about energy use and greenhouse gas emissions, however, are increasing in all industrial sectors. Using a life cycle assessment (LCA) approach, we analyzed the full environmental impacts of producing 99 chemical products in Western Europe from cradle to factory gate. We applied several life cycle impact assessment (LCIA) methods to cover various impact areas. Our analysis shows that for both organic and inorganic chemical production in industrial countries, energy‐related impacts often represent more than half and sometimes up to 80% of the total impacts, according to a range of LCIA methods. Resource use for material feedstock is also important, whereas direct emissions from chemical plants may make up only 5% to 10% of the total environmental impacts. Additionally, the energy‐related impacts of organic chemical production increase with the complexity of the chemicals. The results of this study offer important information for policy makers and sustainability experts in the chemical industry striving to reduce environmental impacts. We identify more sustainable energy production and use as an important option for improvements in the environmental profile of chemical production in industrial countries, especially for the production of advanced organic and fine chemicals.     

Using anticipatory life cycle assessment to enable future sustainable construction

The built environment is the largest single emitter of CO₂ and an important consumer of energy. Much research has gone into the improved efficiency of building operation and construction products. Life Cycle Assessment (LCA) is commonly used to assess existing buildings or building products. Classic LCA, however, is not suited for evaluating the environmental performance of developing technologies. A new approach, anticipatory LCA (a‐LCA), promises various advantages and can be used as a design constraint during the product development stage. It helps overcome four challenges: (i) data availability, (ii) stakeholder inclusion, (iii) risk assessment, and (iv) multi‐criteria problems. This article's contribution to the line of research is twofold: first, it adapts the a‐LCA approach for construction‐specific purposes in theoretical terms for the four challenges. Second, it applies the method to an innovative prefabricated modular envelope system, the CleanTechBlock (CTB), focusing on challenge (i). Thirty‐six CTB designs are tested and compared to conventional walls. Inclusion of technology foresight is achieved through structured scenario analysis. Moreover, challenge (iv) is tackled through the analysis of different environmental impact categories, transport‐related impacts, and thickness of the wall assemblies of the CTB. The case study results show that optimized material choice and product design is needed to reach the lowest environmental impact. Methodological findings highlight the importance of context‐specific solutions and the need for benchmarking new products.