Geographical and technological differences in Life Cycle Inventories shown by the use of process models for waste incinerators

Goal and Background  Geographical and technological differences in Life Cycle Inventory data are an important source for uncertainty in the result of Life Cycle Assessments. Knowledge on their impact on the result of an LCA is scarce, and also knowledge on how to manage them in an LCA case study. Objective  Goal of this paper is to explore these differences for municipal solid waste incinerator plants, and to develop recommendations for managing technological and geographical differences. Methodology  The paper provides a definition of technological and geographical differences, and analyses their possible impacts. In a case study, the differences are caused intentionally in ‘games’, by virtually transplanting incineration plants to a different location and by changing parameters such as the composition of the waste input incinerated. The games are performed by using a modular model for municipal solid waste incinerator plants. In each case, an LCA including an Impact Assessment is calculated to trace the impact of these changes, and the results are compared. Conclusions  The conclusions of the paper are two-fold: (1) reduce the differences in inventory data where their impact on the result is high; where it is possible reducing them to a great extent, and the effort for performing the change acceptable; in the case of incineration plants: Adapt the flue gas treatment, especially a possible DeNOx step, to the real conditions; (2) make use of modular process models that allow adapting plant parameters to better meet real conditions, but be aware of possible modelling errors. We invite the scientific community to validate the model used for a waste incinerator plant, and suggest putting up similar models for other processes, preferably those of similar relevance for Life Cycle Inventories.     

Comparative LCA of industrial objects

Goal, Scope and Background  This paper is the second part of the publication which is devoted to comparative LCA analysis of the industrial pumps. The previous paper deals with the methodological aspects concerning quality assessment and forms an independent work. This paper uses practically only the methodological suggestions made there. The main aim of the presented study is to make a comparison between the industrial pumps which are based on two different technologies. The Life Cycle Assessment method is used to check whether the differences of the manufacturing processes influence the level of the potential environmental impact during the whole life cycle of the analysed products. Methods  The Life Cycle Assessment is carried out using the Ecoindicator99 method. Additionally, an extensive quality analysis of the LCA study is made (Part I). To make the process of an identification of the data easier and faster, they are assigned to a special data documentation form. To ensure the credibility of the LCA results different methods of interpretation are used. Results and Discussion  The LCA analysis shows clear superiority of the pumps manufactured using modern technology. It seems that this superiority results not only from the differences in the emissions, but also from different characteristics of effectiveness in the usage stage. Thanks to the uncertainty analysis, each LCA result is provided with the range of uncertainty. Conclusions  The LCA results are supported by different techniques of interpretation: the sensitivity-, the contribution-, the comparative-, the discernability- and the uncertainty analysis. There is strong evidence of the superiority of the pumps based on the modern technology. Recommendations and Outlook  The main source of the environmental impact in the case of pumps is the usage stage and the consumption of energy. That is why it should be the main area to improve. The LCA results show that actions taken in the usage stage and energy consumption can lead to a considerable reduction of the environmental impacts.     

Accounting for transportation impacts in the environmental assessment of waste management plans

Background, aim, and scope  Many recent studies on waste management have described in detail the potential impacts of recycling and final treatment of municipal waste. In public debates, the attention has also been focused on the choice of final disposal technologies (e.g. landfilling vs. incineration). However, a comprehensive assessment of the impacts of waste collection and transport was still lacking. In the present study, we use LCA to evaluate the potential impact of the provincial waste management plan of Varese (northern Italy). Particular attention is devoted to the estimation of environmental impacts generated during waste transport. Materials and methods  A detailed Life Cycle Inventory was built for the transportation phase, based on primary data collected by interviewing the agencies involved in waste collection. To model the recycling and final disposal phase we relied on the BUWAL 250 database. Impacts were evaluated with the Eco-Indicator 99 method in its egalitarian formulation. Results  The results of our analysis reveal that the major potential impacts of the plan are associated with waste collection and transport. These impacts are partially compensated by reduced resource consumption through recycling and energy recovery through incineration. Discussion  The outputs of the LCIA were compared with those obtained by using other ecoindicators (Eco-Indicator 99 hierarchist and individualist, CML2, EPS2000). Although not comparable on a quantitative basis, they are qualitatively consistent. Conclusions  Neglecting the effects of collection and transport might result in a severe underestimation of the environmental impacts of a waste management system, especially as refers to depletion of fossil fuels, emission of respiratory inorganics and climate change. To reduce the environmental impact of waste management systems, an accurate optimisation of waste transport is required. Recommendations and perspectives  Effective waste management planning requires the explicit inclusion of waste collection and transport when comparing alternative management policies.     

农业生命周期评价研究进展

作为评价产品系统全链条环境影响的有效工具,生命周期评价（LCA）方法已广泛用于工业领域。农业领域也面临着高强度的资源和环境压力,LCA在农业领域的应用应运而生。旨在综述已有农业LCA研究的基础上,鉴别农业LCA应用存在的问题,并为农业LCA未来的发展提出建议。目前农业LCA存在系统边界和功能单位界定不明晰、缺少区域清单数据库、生命周期环境影响评价模型（LCIA）不能准确反映农业系统环境影响、结果解释存在误区等方面的问题。为了科学准确地衡量农业系统的环境影响,促进农业系统的可持续发展,文章认为农业LCA应该从以下几个方面加强研究,即科学界定评价的参照系、系统边界的扩大及功能单位的合理选取、区域异质性数据库构建与LCIA模型开发、基于组织农业LCA的开发以及对于利益相关者行为的研究。     

基于生命周期方法的生活垃圾资源化利用系统生态效率分析

我国生活垃圾产量大但处理能力不足,产生多种环境危害,对其资源化利用能够缓解环境压力并回收资源。为探讨生活垃圾资源化利用策略,综合生命周期评价与生命周期成本分析方法,建立生态效率模型。以天津市为例,分析和比较焚烧发电、卫生填埋-填埋气发电、与堆肥+卫生填埋3种典型生活垃圾资源化利用情景的生态效率。结果表明,堆肥+卫生填埋情景具有潜在最优生态效率;全球变暖对总环境影响贡献最大,而投资成本对经济影响贡献最大。考虑天津市生活垃圾管理现状,建议鼓励发展生活垃圾干湿组分分离及厨余垃圾堆肥的资源化利用策略。     

Life cycle considerations of the flue gas desulphurization system at a lignite-fired power plant in Thailand

Goal, Scope and Background  The Flue Gas Desulphurization (FGD) system has been installed at the biggest lignite-fired power generation plant in Thailand to reduce the large amount of SO₂ emission. In order to understand the costs and benefits, both in ecological and economic terms, the lignite-fired plant was studied both before and after the installation of the FGD system. The focus of this study is to consider not only the Life Cycle Assessment (LCA) outcome but also the Life Cycle Costing (LCC) factors. The results can provide valuable information when selecting appropriate technologies to minimize the negative impact that lignite-fired power plants have on the environment. Methods  The Life Cycle Assessment - Numerical Eco-load Total Standardization (LCA-NETS) system was used to evaluate the impact on the environment of both the lignite-fired plant and the FGD system. Life Cycle Costing (LCC) was used to provide a comparison between alternative before and after installation of FGD. LCC, a powerful analytical tool, examines the total cost, in net present value terms, of a FGD system over its entire service lifetime. Results and Discussion  The results of the study are shown in the eco-load values over the entire life cycle of the lignite-fired plant. Comparative models of the power plant, before and after the installation of the FGD system, are evaluated using the LCA-NETS system. The results indicate that the installation of the FGD system can reduce the acidification problem associated with lignite-fired plants by approximately 97%. The LCC estimation shows the major costs of the FGD system: capital investment, operating and maintenance, and miscellaneous costs. The LCC provides the decision-making information when considering the cost of the FGD system in terms of protecting the environment. Conclusion and Outlook  LCA is an important decision-making tool for environmental policies, especially with regard to the selection of pollution control equipment for lignite-fired plants. Green coal technologies and strategies to reduce the negative impact on the environment are essential to produce more environmentally-friendly power plants with a sustainable future.     

Cradle-to-gate life cycle inventory and assessment of pharmaceutical compounds

Background, Goal and Scope  The research presented here represents one part of GlaxoSmithKline’s (GSK) efforts to identify and improve the life cycle impact profile of pharmaceutical products. The main goal of this work was to identify and analyze the cradle-to-gate environmental impacts in the synthesis of a typical Active Pharmaceutical Ingredient (API). A cradle-to-gate life cycle assessment of a commercial pharmaceutical product is presented as a case study. Methods  Life cycle inventory data were obtained using a modular gate-to-gate methodology developed in partnership with North Carolina State University (NCSU) while the impact assessment was performed utilizing GSK’s sustainability metrics methodology. Results and Discussion  Major contributors to the environmental footprint of a typical pharmaceutical product were identified. The results of this study indicate that solvent use accounts for a majority of the potential cradle-to-gate impacts associated with the manufacture of the commercial pharmaceutical product under study. If spent solvent is incinerated instead of recovered the life-cycle profile and impacts are considerably increased. Conclusions  This case study provided GSK with key insights into the life-cycle impacts of pharmaceutical products. It also helped to establish a well-documented approach to using life cycle within GSK and fostered the development of a practical methodology that is applicable to strategic decision making, internal business processes and other processes and tools.     

Evaluation of two simplified Life Cycle assessment methods

Goal, Scope and Background  Two methods of simplified LCA were evaluated and compared to the results of a quantitative LCA. These are the Environmentally responsible product assessment matrix developed by Graedel and Allenby and the MECO-method developed in Denmark. Methods  We used these in a case study and compared the results with the results from a quantitative LCA. The evaluation also included other criteria, such as the field of application and the level of arbitrariness. Results and Discussion  The MECO-method has some positive qualities compared to the Environmentally responsible product assessment matrix. Examples of this are that it generates information complementary to the quantitative LCA and provides the possibility to consider quantitative information when such is available. Some of the drawbacks with the Environmentally responsible product assessment matrix are that it does not include the whole lifecycle and that it allows some arbitrariness. Conclusions  Our study shows that a simplified and semi-quantitative LCA (such as the MECO-method) can provide information that is complementary to a quantitative LCA. In this case the method generates more information on toxic substances and other impacts, than the quantitative LCA. We suggest that a simplified LCA can be used both as a pre-study to a quantitative LCA and as a parallel assessment, which is used together with the quantitative LCA in the interpretation. Recommendations and Outlook  A general problem with qualitative analyses is how to compare different aspects. Life cycle assessments are comparative. The lack of a quantitative dimension hinders the comparison and can thereby hinder the usefulness of the qualitative method. There are different approaches suggested to semiquantify simplified methods in order to make quantitative comparisons possible. We think that the use of fabricated scoring systems should be avoided. If quantitative information is needed, one should consider performing a simplified quantitative LCA instead.     

Comparative life cycle assessment of two landfill technologies for the treatment of municipal solid waste

Goal and Scope  The potential environmental impacts associated with two landfill technologies for the treatment of municipal solid waste (MSW), the engineered landfill and the bioreactor landfill, were assessed using the life cycle assessment (LCA) tool. The system boundaries were expanded to include an external energy production function since the landfill gas collected from the bioreactor landfill can be energetically valorized into either electricity or heat; the functional unit was then defined as the stabilization of 600 000 tonnes of MSW and the production of 2.56x10⁸ MJ of electricity and 7.81x10⁸ MJ of heat. Methods  Only the life cycle stages that presented differences between the two compared options were considered in the study. The four life cycle stages considered in the study cover the landfill cell construction, the daily and closure operations, the leachate and landfill gas associated emissions and the external energy production. The temporal boundary corresponded to the stabilization of the waste and was represented by the time to produce 95% of the calculated landfill gas volume. The potential impacts were evaluated using the EDIP97 method, stopping after the characterization step. Results and Discussion  The inventory phase of the LCA showed that the engineered landfill uses 26% more natural resources and generates 81% more solid wastes throughout its life cycle than the bioreactor landfill. The evaluated impacts, essentially associated with the external energy production and the landfill gas related emissions, are on average 91% higher for the engineered landfill, since for this option 1) no energy is recovered from the landfill gas and 2) more landfill gas is released untreated after the end of the post-closure monitoring period. The valorization of the landfill gas to electricity or heat showed similar environmental profiles (1% more raw materials and 7% more solid waste for the heat option but 13% more impacts for the electricity option). Conclusion and Recommendations  The methodological choices made during this study, e.g. simplification of the systems by the exclusion of the identical life cycle stages, limit the use of the results to the comparison of the two considered options. The validity of this comparison could however be improved if the systems were placed in the larger context of municipal solid waste management and include activities such as recycling, composting and incineration.     

LCA in Japan: policy and progress

A summary of the current Japanese activities related to Life Cycle Assessment are presented with a specific comparison of Life Cycle Impact Assessment in relation to European tendencies. Japanese organizations involved in LCA, recent legislation impacting LCA activities and LCA case studies are also tabulated. The LCA priorities of policy makers and industrialists are discussed in comparison and compared to those in the United States. Projects within the Life Cycle Assessment Society of Japan and the Man-Earth Project are highlighted including the construction of a public LCI data base and the prediction of 21st century environmental crises.     

Missing inventory estimation tool using extended input-output analysis

Intention, Goal, Scope, Background  Input-Output Analysis (IOA) has recently been introduced to Life Cycle Assessment (LCA). In applying IOA to LCA studies, however, it is important to note that there are both advantages and disadvantages. Objectives  This paper aims to provide a better understanding of the advantages and disadvantages of adopting IOA in LCA, and introduces the methodology and principles of the Missing Inventory Estimation Tool (MIET) as one of the approaches to combine the strengths of process-specific LCA and IOA. Additionairy, we try to identify a number of possible errors in the use of IOA for LCA purposes, due to confusion between industry output and commodity, consumer’s price and producer’s price. Method  MIET utilises the 1996 US input-output table and various environmental statistics. It is based on an explicit distinction between commodity and industry output. Results and Discussion  MIET is a self-contained, publicly available database which can be applied directly in LCA studies to estimate missing processes. Conclusion  By adopting MILT results in existing, process-based, life-cycle inventory (LCI), LCA practitioners can fully utilise the process-specific information while expanding the system boundary. Recommendations and Outlook  MIET will be continuously updated to reflect both methodological developments and newly available data sources. For supporting information sec http:// wwwJeidenuniv.nl/cml/ssp/softwarc/miet.     

Stakeholder involvement in australian paper and packaging waste management LCA study

Intention, Goal, Scope, Background  To discuss the process of stakeholder involvement as undertaken in a post-consumer paper and packaging waste management LCA study conducted during 1997-2001 for the Melbourne Metropolitan Area, Victoria, Australia. Secondly, to present the findings from a survey conducted with the stakeholder groups regarding their perception of involvement in the project. Objectives  To investigate the stakeholder’s perception; and value of being involved in the LCA study intended to generate quantitative environmental information to support debate, development and implementation of waste management practices. Methods  Stakeholders that were involved in the study, both actively and passively, were surveyed by questionnaire Survey findings were analysed in conjunction with stakeholder interaction experiences obtained in the course of the study. as]Results and Discussion Respondents to the survey believed there was a sufficient level of interaction between stakeholders and researchers during the course of the project. The advisory committee approach helped to timely recognize issues and deal with them appropriately. It furdier assisted in the collection of life cycle inventory data and in obtaining ownership of outcomes by the research ream appropriately responding to the needs and issues raised by stakeholders. Recommendations and Outlook  General recommendations for the inclusion of stakeholders in future studies are to use stakeholder interactions, wherever it is possible and practical, which in turn play an educational role, engage stakeholders from the start of the process and allow additional time in the project plan for review stages, as well as ensuring that all relevant groups are represented — industry, industry associations, government and non-governmental organizations, and also provide sufficient material and progress for discussion at meetings.     

Use of Incinerator Bottom Ash for Frit Production

This article presents the results of an experimental activity aimed at investigating the technical feasibility and the environmental performance of using municipal solid waste incineration bottom ash to produce glass frit for ceramic glaze (glaze frit). The process includes an industrial pretreatment of bottom ash that renders the material suitable for use in glaze frit production and allows recovery of aluminum and iron. The environmental performance of this treatment option is assessed with the life cycle assessment (LCA) methodology. The goal of the LCA study is to assess and compare the environmental impacts of two scenarios of end of life of bottom ash from municipal solid waste incineration (MSWI): landfill disposal (conventional scenario) and bottom ash recovery for glaze frit production (innovative scenario). The main results of the laboratory tests, industrial simulations, and LCA study are presented and discussed, and the environmental advantages of recycling versus landfill disposal are highlighted.     

Efficient information visualization in LCA: Application and practice

Aim, Scope and Background  Acquisition and analysis of huge amounts of data still pose a challenge, with few options available for solutions and support. Life cycle assessment (LCA) experts face such problems on a daily basis. However, data do not become useful until some of the information they carry is extracted, and most important, represented in a way humans can both recognize efficiently and understand and interpret as quickly as possible. Unfortunately, information representation techniques as used in this field are still based on traditional low-dimensional information spaces, featuring only a few basic choices to represent life cycle (LC) related data. We must part from those traditional techniques and shift to visual representations that are easier for us to understand due to the human capability for detecting spatial structures and shapes represented in different colors and textures. Then all the advantages of modern, advanced information visualization can be applied and exploited. Main Features  With the introduction of a new glyph-based information representation and visualization approach to LCA, current issues of representing LC-related information efficiently at a glance are being tackled. These new techniques support reduction of information load by providing tools to select and summarize data, assist in making explicit and transparent data feature propagation, and provide a means of representing data errors and uncertainty. In this approach the human perceptual capability for easily and quickly recognizing and understanding graphical objects in different colors and textures is exploited for the design and application of highly structured and advanced forms of multi-dimensional information representation. Results  Now in the example presented in this paper, OM-glyphs were used to represent LCA-related information for an industrial product and its compiled life cycle inventory under conditions normal for LCA. To demonstrate the application and benefits of the approach introduced, several different visualization scenarios were computed and presented. These were illustrated with a selection of generated glyph-based displays containing spherical glyph clusters for environmental items such as air pollutants and water pollutants, and inventory glyph matrices related to components and to LC phases. Where appropriate, to further aid understanding and clarity, displays were additionally shown with various orientations and in enlarged form. This is a functional feature of interactive 3D OM-glyph based information visualization that can be used in practice to efficiently navigate through displays while at the same time adjusting rendered scenes to the needs of the user at any given time. Due to the huge amount of data acquired and compiled, only a small fraction of the glyph-based displays could be shown, and, in consequence, only a fraction of the data properties, patterns and features available could be discussed in detail. However, it is believed that the basic principles and methods of this approach, as shown in a real application, could be clearly conveyed, and, most important, that the benefits and potential could be displayed in a convincing manner. This technology will support a marked increase in efficiency, speed and quality in LC information analysis. Conclusions  This paper concludes our short series on efficient information visualization in LCA. A new approach to efficient information visualization has been introduced, together with its basic principles. This background was enriched with discussions on and further insights into technical details of the approach and the framework developed. The first practical examples were provided in the previous paper, demonstrating the mapping of LCA-related data and their contexts to glyph parameters. In this paper the application of the approach was presented using data for an actual industrial product. During the discussions, and with the various glyph-based displays shown, it could be convincingly demonstrated that all data features, trends, patterns, relationships, and data imperfections detected and examined, and sometimes traced, could be quickly and efficiently recognized in a short time. Even basic data features, such as small gaps in the data propagation of related values, could be easily seen using OM-glyphs. In the case of traditional data representation, using for example LCI tables, this would require the identification and comparison of several thousand numerical entries. As is the case with all new technology, however, it is still difficult to obtain the interest of the experts, and to convince them that such new ideas will eventually change the face of industry. Outlook  A new, advanced and efficient information representation and visualization approach has been introduced to the LCA community. Hopefully, through this small series of papers, some interest will have been generated in the field of advanced information visualization. For the first time this area has been related to LCA, and some seeds for interdisciplinary research may have been sown. Now it is up to individuals, the experts in the various fields elated to those issues, to respond. The desired results will be stimulating discussions, an exchange of ideas, further initiated multilateral, interdisciplinary efforts, and improved collaboration between partners from academia and industry. At that point, efficient information visualization will finally have arrived at, and received, its deserved place within LCA.     

Ecological Toxicity Methods and Metals. An examination of two case studies (8 pp + 1)

Goal, Scope and Background The Apeldoorn Workshop (April 15th, 2004, Apeldoorn, NL) brought together specialists in LCA and Risk Assessment to discuss current practices and complications of the life cycle impact assessment (LCIA) ecological toxicity (ecotox) methodologies for metals. The consensus was that the LCIA methods currently available do not appropriately characterize impacts of metals due to lack of fundamental metals chemistry in the models. A review of five methods available to perform ecotox impact assessment for metals has been prepared to provide Life Cycle Assessment (LCA) practitioners with a better understanding of the current state of the science and potential biases related to metals. The intent is to provide awareness on issues related to ecotox impact assessment. Methods In this paper two case studies, one a copper based product (copper tube), the other a zinc-based product (gutter systems), were selected and examined by applying freshwater ecological toxicity impact models – USES-LCA, Eco-indicator 99 (EI 99), IMPACT 2002, EDIP 97, and CalTOX-ETP. Both studies are recent, comprehensive, cradle-to-gate, and peer-reviewed. The objective is to review the LCIA results in the context of the practical concerns identified by the Apeldoorn Declaration, in particular illustrating any inconsistencies such as chemical characterization coverage, species specificity, and relative contribution to impact results. Results and Discussion The results obtained from all five of the LCIA methods for the copper tube LCI pointed to the same substance as being the most important – copper. This result was obtained despite major fundamental differences between the LCIA methods applied. However, variations of results were found when examining the freshwater ecological toxicity potential of zinc gutter systems. Procedural difficulties and inconsistencies were observed. In part this was due to basic differences in model nomenclature and differences in coverage (IMPACT 2002+ and EDIP 97 contained characterization factors for aluminium that resulted in 90% and 22% contribution to burden respectively, the other three methods did not). Differences were also observed relative to the emissions source compartment. In the case of zinc, air emissions were found to be substantial for some ecotox models, whereas, water emissions results were found to be of issue for others. Conclusions This investigation illustrates the need to proceed with caution when applying LCIA ecotox methodologies to life cycle studies that include metals. Until further improvements are made, the deficiencies should be clearly communicated as part of LCIA reporting. Business or policy decisions should not without further discussion be based solely on the results of the currently available methods for assessing ecotoxicity in LCIA. Outlook The outlook to remedy deficiencies in the ecological toxicity methods is promising. Recently, the LCIA Toxic Impacts Task Force of the UNEP/SETAC Life Cycle Initiative has formed a subgroup to address specific issues and guide the work towards establishment of sound characterization factors for metals. Although some measure of precision of estimation of potential impact has been observed, such as in the case of copper, accuracy is also a major concern and should be addressed. Further investigation through controlled experimentation is needed, particularly LCIs composed of a variety of inorganics as well as organics constituents. Support for this activity has come from the scientific community and industry as well. Broader aspects of structure and nomenclature are being collectively addressed by the UNEP/SETAC Life Cycle Initiative. These efforts will bring practical solutions to issues of naming conventions and LCI to LCIA flow assignments.     

Life cycle assessment of a pyrolysis/gasification plant for hazardous paint waste

Goal, Scope and Background Life Cycle Assessment (LCA) remains an important tool in Dutch waste management policies. In 2002 the new National Waste Management Plan 2002–2012 (NWMP) became effective. It was supported by some 150 LCA studies for more than 20 different waste streams. The LCA results provided a benchmark level for new waste management technologies. Although not new, operational techniques using combined pyrolysis/gasification are still fairly rare in Europe. The goal of this study is to determine the environmental performance of the only full scale pyrolysis/gasification plant in the Netherlands and to compare it with more conventional techniques such as incineration. The results of the study support the process of obtaining environmental permits. Methods In this study we used an impact assessment method based on the guidelines described by the Centre of Environmental Science (CML) of Leiden University. The functional unit is defined as treatment of 1 ton of collected hazardous waste (paint packaging waste). Similar to the NWMP, not only normalized scores are presented but also 7 aggegated scores. All interventions from the foreground process (land use, emissions, final waste) are derived directly from the site with the exception of emissions to soil which were calculated. Interventions are accounted to each of the different waste streams by physical relations. Data from background processes are taken from the IVAM LCA database 4.0 mostly originating from the Swiss ETH96 database and adapted to the Dutch situation. Allocation was avoided by using system enlargement. The study has been peer reviewed by an external expert. Results and Discussion It was possible to determine an environmental performance for the pyrolysis/ gasification of paint packaging waste. The Life Cycle Inventory was mainly hampered by the uncertainty occurred with estimated air emissions. Here several assumptions had to be made because several waste inputs and two waste treatment installations profit from one flue gas cleaning treatment thus making it difficult to allocate the emission values from the flue gasses. Compared to incineration in a rotary kiln, pyrolysis/gasification of hazardous waste showed better scores for most of the considered impact categories. Only for the impact categories biodiversity and life support the incineration option proved favorable due to a lower land use. Several impact categories had significant influence on the conclusions: acidification, global warming potential, human toxicity and terrestrial ecotoxicity. The first three are related to a better energy efficiency for pyrolysis/gasification leading to less fossil energy consumption. Terrestrial ecotoxicity in this case is related to specific emissions of mercury and chromium (III). A sensitivity analysis has been performed as well. It was found that the environmental performance of the gasification technique is sensitive to the energy efficiency that can be reached as well as the choice for the avoided fossil energy source. In this study a conservative choice for diesel oil was made whereas a choice for heavy or light fuel oil would further improve the environmental profile. Conclusions Gasification of hazardous waste has a better environmental performance compared to the traditional incineration in rotary kilns mainly due to the high energy efficiency. As was determined by sensitivity analysis the differences in environmental performance are significant. Improvement options for a better performance are a decrease of process emissions (especially mercury) and a further improvement of the energy balance by decreasing the electricity consumption for shredders and oxygen consumption or making more use of green electricity. Recommendations and Perspectives Although the life cycle inventory was sufficiently complete, still some assumptions had to be made in order to establish sound mass balances on the level of individual components and substances. The data on input of waste and output of emissions and final waste were not compatible. It was recommended that companies put more emphasis on data storage accounted to particular waste streams. This is even more relevant since more companies in the future are expected to include life cycle impacts in their environmental performance.     

Comparative evaluation of Life Cycle Impact assessment methods with a South African case study

Goal and Background  LCIA procedures that have been used in the South Africa manufacturing industry include the CML, Ecopoints, EPS and Eco-indicators 95 and 99 procedures. The aim of this paper is to evaluate and compare the applicability of these European LCIA procedures within the South African context, using a case study. Methods  The five European methods have been evaluated based on the applicability of the respective classification, characterisation, normalization and weighting approaches for the South African situation. Impact categories have been grouped into air, water, land and mined abiotic resources for evaluation purposes. The evaluation and comparison is further based on a cradle-to-gate Screening Life Cycle Assessment (SLCA) case study of the production of dyed two-fold wool yarn in South Africa. Results and Discussion  Where land is considered as a separate category (CML, Eco-indicator 99 and EPS), the case study highlights this inventory constituent as the most important. Similarly, water usage is shown as the second most important in one LCIA procedure (EPS) where it is taken into account. However, the impact assessment modelling for these categories may not be applicable for the variance in South African ecosystems. If land and water is excluded from the interpretation, air emissions, coal usage, ash disposal, pesticides and chrome emissions to water are the important constituents in the South African wool industry. Conclusions  In most cases impact categories and procedures defined in the LCIA methods for air pollution, human health and mined abiotic resources are applicable in South Africa. However, the relevance of the methods is reduced where categories are used that impact ecosystem quality, as ecosystems differ significantly between South Africa and the European continent. The methods are especially limited with respect to water and land resources. Normalisation and weighting procedures may also be difficult to adapt to South African conditions, due to the lack of background information and social, cultural and political differences. Recommendations and Outlook  Further research is underway to develop a framework for a South African LCIA procedure, which will be adapted from the available European procedures. The wool SLCA must be revisited to evaluate and compare the proposed framework with the existing LCIA procedures.     

Life cycle and matrix analyses for re-refined Oil in Japan

Unstable market systems and consumer preferences for virgin oil have inhibited the development of waste oil re-refining in Japan. In this papery comparative life cycle inventories were developed for re-refining waste oil and for the no-refining case in which the waste oil is incinerated and needs are supplied with virgin oil. Total energy, CO₂, NO_x, and SO₂ emissions were included during the re-refining and consumption (incineration) stages; all are lower in the case of re-refined fuel use. In addition, by using a streamlined LCA matrix, we demonstrate that re-refining waste oil can reduce environmental impacts compared with the case in which virgin oil is chosen.     

Application of data quality assessment methods to an LCA of electricity generation

Background, Goal and Scope  For the life cycle assessment (LCA) tool to provide maximum benefit for decision makers, the uncertainty of its results should be reported. Several methods for assessing uncertainty have been developed, but despite recent efforts, there remains disagreement about their merits. Objectives  The objectives of the study were to review several assessment methods for estimating numerical and qualitative uncertainty of impact scores and recommend an appropriate uncertainty assessment scheme. The methods review has been conducted on the basis of an LCA case study regarding the comparison of the use of either brown or black coals in Australian electricity generation. Results and Discussion  Each assessment method indicated greater uncertainty in the impact scores calculated for black coal use than for brown coal use. Due to overlap of the uncertainty ranges in calculated impact scores neither of the coals could be regarded environmentally preferred. Conclusions  Both qualitative and quantitative methods were found to provide useful information about the uncertainty of calculated impact scores for the case study. Methods that combine qualitative and quantitative uncertainty provided no additional benefits, and obscured much of the information gained from using qualitative methods. Recommendation and Outlook  It is recommended that LCA results should include separate numerical (using Monte-Carlo simulation) and qualitative uncertainty assessments. When the ranges of calculated impact scores for compared options overlap, the normalised difference method is recommended.     

Carbon and Water Footprints and Energy Use of Greenhouse Tomato Production in Northern Italy

This study reports on the carbon, water, and energy footprints of tomatoes grown in a greenhouse in Northern Italy and two possible future variations of heating and carbon dioxide (CO₂) fertilization on the current setup. The heat supply in place, consisting of natural gas (NG) and canola oil combustion, is compared to cogeneration and incineration of municipal solid waste for heating and CO₂ from industrial exhaust for fertilization. As a benchmark, the current system is also compared to a conventional system, in which heat is delivered solely based on NG. Each kilogram (kg) of fresh tomatoes (“Cuore di Bue” variety) produced in the current greenhouse emits 2.28 kg CO₂ equivalents (eq) and uses 95.5 megajoules (MJ) eq energy and 122 liters (L) of water. Relative to the system in place, the carbon footprint (CF) is 57.5% and 18% higher with conventional NG heating and cogeneration and is 40% lower with waste valorization. Further, 33%, 55%, and 63% less energy and 9%, 96%, and 14% less water are used in the conventional, cogeneration, and waste valorization scenarios, respectively. This confirms that there are multiple strategies to reduce the impact of the tomato production under consideration.