Development of a life cycle assessment tool for construction and maintenance of asphalt pavements

The increasing use of recycled materials in asphalt pavements calls for environmental assessment of such impacts as the energy input and CO₂ footprint. Life cycle assessment (LCA) is being accepted by the road industry for such purpose. It aims to quantify and collate all the environmental impacts from the life time of the product or process. This paper reviews relevant LCA resources worldwide, identifies the knowledge gap for the road industry, and describes the development of an LCA model for pavement construction and maintenance that accommodates recycling and up-to-date research findings. Details are provided of both the methodology and data acquisition. This is followed by a discussion of the challenges of applying LCA to the pavement construction practice, and recommendations for further work. In the case study, the model is applied to an asphalt paving project at London Heathrow Terminal-5 (LHR), in which natural aggregates were replaced with waste glass, incinerator bottom ash (IBA) and recycled asphalt pavements (RAP). Production of hot mix asphalt and bitumen was found to represent the energy intensive processes. This is followed by data analysis and sensitivity check. Further development of the model includes expanding the database to accommodate the recycling and maintenance practice in the UK, and taking into account the effect that roadwork has on traffic emissions. The LCA model can be further tested and calibrated as a decision support tool for sustainable construction in the road industry.     

Life cycle assessment applied to egg packaging made from polystyrene and recycled paper

In the present study, the application of life cycle assessment (LCA) for the comparison of two egg packages, from polystyrene and recycled paper, is presented. The input and output streams of mass and energy are examined and the environmental impacts associated with the two systems are analyzed. The application of LCA by using EcoIndicator 95 has made possible the comparison of the environmental impacts of two egg packages. The results of this LCA study are discussed and reveal that the PS packages contribute more to acidification potential, winter and summer smog, while recycled paper egg packages contribute more to heavy metal and carcinogenic substances impact. Nevertheless, it seems that paper eggcups have less environmental impact than the polystyrene ones with the assumption that the accuracy of the results is confined by the credibility of European databases used for primary data.     

生命周期评价在企业环境管理中的应用

环境管理对于企业的可持续发展起着决定性的作用,生命周期评价作为面向产品系统的新型环境管理工具越来越多地被企业所采用。文章结合中国企业环境管理实际,对所采用的环境管理工具做了分类,详述了生命周期评价的具体应用以及优势。对生命周期评价在未来企业环境管理中的重要作用做了展望。     

Environmental management and life cycle approaches in the Mexican mining industry

Mexico ranks among the 11 major producer countries of minerals worldwide; its open pit and underground systems are 500 years old. This paper presents an overview of the Mexican mining industry from technological development, historical and economic perspectives. The efforts made by mining companies to address issues of environmental management and sustainable development expressed in national and international frameworks, as well as the Mexican environmental regulatory framework for the mining sector, are analyzed. Since, among others, life cycle assessment (LCA) has been recognized as a key topic to promote sustainable development in the Latin American and Caribbean region, this paper also examines the application of LCA in mining. Two life cycle approaches are presented: a national life cycle inventory for base metals, and an integral life cycle model for the management of mining processes.     

Some requirements of an interactive software tool for life cycle analysis

This paper briefly presents the current practice for carrying out life cycle inventories, and mentions some advantages and drawbacks of a few dedicated software tools that are commercially available. A list is presented of some features that we think should be present in an ‘ideal’ life cycle analysis (LCA) software tool, after the specifications made at Ecobilan for the development of a specific tool for LCA. Some consideration is given to the technical difficulties involved, and the benefits that could be expected from the implementation of such features.     

A comparative study on milk packaging using life cycle assessment: from PA-PE-Al laminate and polyethylene in China

A Life Cycle Assessment (LCA) approach was used to compare the environmental impacts in the life cycle of two milk packaging systems, PA-PE-Al laminate—a laminated foil made from paper, polyethylene and aluminum foil—and polyethylene. The data for the mass, energy fluxes and environmental emissions were obtained from published literature and from site investigations, for the two systems being analyzed for environmental impacts. The application of LCA using Eco-Indicator 99 has made the comparison of the environmental impacts of the two milk packages possible. The results of this LCA study are discussed and the results reveal that the composite packaging has a slightly higher environmental impact than the plastic one. In addition, the environmental impact of raw material extraction is the highest in all of the life cycle stages except for disposal. The environmental impact of composite packaging mainly comes from the fossil fuels, land use and respiratory inorganics categories, while the plastic packaging mainly comes from the fossil fuels category. However, the composite packaging has a greater environmental impact because it has not been well recycled and reused. This environmental impact could be decreased by developing the technology to separate out polyethylene and aluminum from the packaging.     

Normative ethics and methodology for life cycle assessment

Prospective life cycle assessment (LCA) provides information on the environmental consequences of individual actions. Retrospective LCA provides information about the environmental properties of the life cycle investigated and of its subsystems. In this paper we analyse the links between the choice of methodology and different theories of normative moral philosophy. The choice of electricity data in an LCA of a conference site with local hydropower production is discussed as an illustration. The two types of LCA can be related to different theories on the characteristics of a good action. Each type of LCA, as well as each of the moral theories, can be criticised from the alternative point of departure. Decisions based on retrospective LCA can have environmentally undesirable consequences. On the other hand, prospective LCA can appear unfair and result in environmentally sub-optimised systems. Both types of LCA also have methodological limitations. We cannot conclude that one type is superior to the other, but the choice of methodology should be consistent with the information sought in the LCA.     

LCA中清单分析数据的获得

清单分析是ＬＣＡ继目标界定后的一步重要操作,工业量极大,本文从我国具体情况出发,开发了一套获取产品ＬＣＡ清单数据的方法,介绍了通过行业污染系数获取产品的社会数据以及借助企业生产的质量流程图收集和检验企业数据的具体步骤。     

On uncertainty and sensitivity of LCA-based priority setting

Life-cycle assessments are normally made without quantitative estimations of their uncertainty. More interest has been focused on sensitivity analysis. In ISO 14040, LCA standard and SETAC's ‘code of practice’ sensitivity and uncertainty analysis are recommended or even requested. In the EPS system, an analysis of significance and sensitivity has been carried out for several years. The article describes this procedure in ISO terms and generalises it for other types of life-cycle assessments.     

Characterizing the change of land-use based on flora: application for EIA and LCA

The environmental impact of land-use can be expressed in terms of a change in biodiversity of flora. We present two models that characterize the negative effects of land-use: a model on the basis of species richness; a model on the basis of the rarity of ecosystems and their vascular plants. Each of those models may serve in the EIA (environmental impact assessment) of the urban and rural planning of expanding cities, industrial areas, road infrastructure, etc. Moreover, these models might be applied by Life Cycle Analysis (LCA) practitioners to incorporate the aspect of land-use in the environmental assessment of a specific product design. The results of both models have been applied in practice. Maps of The Netherlands are provided for both models. The map based on the rarity of ecosystems differentiates the best of what experts (biologists and ecologists) define as botanical quality of nature; the methodology is operational in The Netherlands and might be applied to other countries as well, however, detailed botanical information is required. The map based on species richness has a weaker compliance with the botanical quality of nature, however, the model can more easily be applied to a wider area of the world, since indicative data about species richness is available on a global scale. The so called ‘eco-costs of land conversion’ is proposed as a single indicator, being the marginal costs of prevention (or compensation) of the negative environmental effects on biodiversity caused by change of land-use. These ‘eco-costs of land conversion’ for the botanical aspects are part of the much broader model of the eco-costs/value ratio, which has recently been published in this journal [Vogtländer et al., Journal of Cleaner Production 2002;10:57–671].     

Does the potential of the use of LCA match the design team needs?

Today, most people involved in the industrial engineering community (consultants, manufacturers, researchers and institutional actors) assert that Life Cycle Assessment (LCA) is the most successful tool to assess environmental considerations in the product design process. This assertion is addressed in this article through a simultaneous check of the potential of this tool and the environmental needs of the design team. After a comparison of this potential to these needs, the following assertions may be made: (1) LCA is not an adequate tool for the designer, because its utility in the design process is limited to an analysis of existing products or well defined products at the final stages of the design process, and (2) LCA is not useful in creating a learning dynamic (awareness) within the company, because it does not improve the legitimacy or the credibility of environmental considerations. Moreover, it may generate confusion within the design team while restricting the capacity for innovation within the company. This paper concludes that, in the product design field, the LCA tool should be considered as a specialized tool handled by a specific player (the environmental actor) and should be dedicated to the strategic evaluation of new concepts.     

中国生命周期参考数据库的建立方法与基础模型

缺乏完善的本地化LCA(Life Cycle Assessment)数据库是国内广泛开展LCA研究与应用的主要障碍.本文总结提出了建立中国生命周期参考数据库(Chinese Reference Life Cycle Database,CLCD)的基本方法,包括环境影响类型与物质名录的选择、单元过程清单数据的收集与审核、生命周期清单数据的建模与计算、CLCD数据库的建立等4个方面.按照上述方法,以电力、煤炭、燃油、运输等基础性产品为核心,初步建立了可扩展的中国基础工业系统的生命周期模型,收集了单元过程的全国平均清单数据,通过模型计算获得了这些基础性产品的生命周期清单数据,从而得到了CLCD基础数据库,为下一步扩展为更完善的CLCD数据库提供了方法与模型基础.     

Mining life cycle modelling: a cradle-to-gate approach to environmental management in the minerals industry

It is common practise in mining Life Cycle Assessment (LCA) studies to use a predefined set of data to represent mining production systems. Besides this, very little is added to improve data quality, and essential mining process details which affect the ultimate environmental impacts is rarely taken into account. Some significant omissions include exploration and development work, mining method used, production, ore losses, location and the mining/processing method dependent factors that govern the nature of discharges to the environment. The mining system is often represented as a black-box, not lending itself to the interpretation of different processes used in minerals production. The generic data used are often inadequate for a mining LCA, and cannot be used as an accurate account of mining environmental burdens contributing to more complex systems “down-stream”, such as metals, building, chemical or food industries. Therefore, the main objective of the mining LCA model presented in this paper was to develop a tool that is able to represent the mining system in a comprehensive way. To attain this objective, the mining system was studied in more detail, as it is commonly practised during mine feasibility and design stages. It (LICYMIN) was developed as part of an international research project led by Imperial College London. The model integrates the mine production, processing, waste treatment and disposal, rehabilitation and aftercare stages of a mine's life within an LCA framework. The development work was carried out in collaboration with several industrial partners in Europe, including Bakonyi Bauxitbánya Kft. in Hungary. The model structure, database development and examples of field applications from industrial sites are presented.     

咪唑基离子液体用于天然气脱水过程中的技术-环境评价

利用Aspen Plus建立离子液体天然气脱水的工艺流程模拟,结合灵敏度分析及生命周期评价方法,对该工艺应用不同离子液体产生的技术及环境影响进行比较,并分析离子液体结构对天然气脱水工艺技术及环境评价的影响。结果表明:与烷基链较短的阳离子结合的[BF₄]-离子液体具有较好的脱水性能（[EMIM][BF₄]>[BMIM][BF₄]>[OMIM][BF₄]）;对于生产1 kg甲烷气体而言,[BMIM][PF₆]脱水法的环境影响最大,达到[OMIM][BF₄]脱水法环境影响的5倍;此外,对于具有相同阴离子[BF₄]-的脱水情况,环境影响顺序为[OMIM][BF₄]<[BMIM][BF₄]<[EMIM][BF₄]。该结果从技术和环境评价的角度为筛选或开发天然气脱水过程中选择适当的离子液体提供了指导。     

Life cycle assessment of electricity generation from bagasse in Mauritius

This paper presents the findings of a life cycle assessment (LCA) of electricity generated from the combustion of sugar cane bagasse in Mauritian sugar mills. The study arose from the identification of the need for to provide data for the development of an LCA profile for the electricity mix in Mauritius. The system is limited geographically to the island of Mauritius and is intended to be the representative of current agricultural techniques practiced and current manufacturing processes used by Mauritian sugar mills. The unit operations that make up the system are the growing and harvesting of sugar cane, the transport of the harvested cane to sugar mills, the production of bagasse as a by-product from the sugar milling process, and the combustion of bagasse to generate heat and electricity. The functional unit of the study is the generation of 1 GWh of electricity exported to the national electricity grid. The characterised data for 1 GWh of bagasse-derived electricity were compared with data for 1 GWh of coal-derived electricity, using the same set of characterisation factors. The results of this comparison indicate that bagasse-derived electricity performs well in the areas of greenhouse gas emissions, acidification, and non-renewable energy inputs, but performs poorly in relation to water consumption and eutrophication.     

Manufacturing actor’s LCA

Modern industrial environmental management encompasses life-cycle thinking. This entails considering not only the emissions and resource use of the company’s production processes, but also the environmental consequences of all processes related to a product’s life cycle. However, no single actor can influence the whole life cycle of a product. To be effective, analysis methods intended to support improvement actions should therefore also consider the decision makers’ power to influence.Regarding the life cycle of a product, there are at least as many perspectives on life-cycle thinking as there are actors. This paper presents an approach with which manufacturing decision makers can sharpen the focus in life-cycle assessment (LCA) from a conventional ‘products or services’ emphasis to a company’s manufacturing processes. The method has been developed by combining knowledge gained from earlier LCA studies with new empirical findings from an LCA study of an SKF manufacturing line.We demonstrate how system boundaries and functional units in an LCA can be defined when adding the perspective of a manufacturing decision maker to the product life-cycle perspective. Such analysis helps manufacturing decision makers identify improvement potentials in their spheres of influence, by focusing on the environmental consequences of energy and material losses in manufacturing rather than merely accounting for the contributions of individual stages of the life cycle to the overall environmental impact. The method identifies and directly relates the environmental consequences of emissions or raw material inputs in the product life cycle to manufacturing processes. In doing so, the holistic systems perspective in LCA is somewhat diminished in favor of the relevance of results to manufacturing decision makers.     

Solid waste treatment within the framework of life-cycle assessment

Traditionally, treatment of solid waste has been given limited attention in connection with life-cycle assessments (LCAs). Often, only the amounts of solid wastes have been noted. This is unsatisfactory since treatment of solid waste, e.g. by landfilling or incineration, is an operation, requiring inputs and producing outputs, which should be described in the inventory of an LCA, in parallel to other operations. However, there are difficulties in describing emissions from solid waste treatments and there is a need for development of such methods. In this paper an approach for describing emissions from incineration and landfilling is outlined. Methodological questions concerning the time-frame and allocation principles are discussed. Methods for estimating potential emissions from landfilling of municipal solid waste and industrial wastes are suggested. The methods are used for calculating potential emissions from landfilling of some typical wastes. These emissions are compared with the emissions from other stages in the life cycle for some materials and wastes. it is shown that the potential emissions from landfilling are, for some products, of importance for the final results. Hence, if emissions from landfilling are neglected, or underestimated, results and conclusions in an LCA may be misleading.     

An inventory analysis of oil shale energy produced on a small thermal power plant

Energy produced in Estonia from oil shale is studied using the inventory analysis of the product life cycle assessment (LCA) method. The life cycle is taken as an oil shale mine and thermal power plant with consumer supply systems, which are close to each other and are technologically interconnected.The effectiveness of energy production over the whole life cycle is calculated and the energy and the material balances are presented. Local environmental effects of the oil shale extraction and the energy production are briefly described.The first step in defining the oil shale energy as an important input parameter for the LCA studies of all other products of Estonia is made. The collected data can serve as a basis for the environmental improvement programs.     

Identification of key issues for further investigation in improving the reliability of life-cycle assessments

The interative nature of life-cycle assessment (LCA) means that more details are looked for until a certain level of reliability has been achieved. This paper is concerned with the identification of key issues for further investigation in such an iterative procedure. Key issues in this context are defined as those aspects of an LCA which need more detailed research to arrive at a solid conclusion. The main concept in the context of finding key issues is the study of the propagation of uncertainties in underlying data. The structured procedure of LCA can be described in mathematical terms, so that standard mathematical techniques for the study of the propagation of uncertainties can be employed. The influence of uncertainties in input data on uncertainties in output data can be calculated, and the main source of the resulting uncertainties can be identified. The result of the analysis is a list of prioritized key issues for more detailed research and more accurate data.     

LCA环境影响分析新探

影响分析是ＬＣＡ的核心内容,也是难度最大的部分。目前采用的定性方法和定量方法都存在不少缺点。本文在笔者构筑的ＬＣＡ指标体系的基础上探索在影响分析中引入了我国现行的环境质量评价方法和手段使影响分析的方法更易于操作,其结果更具有客观性和可比性。本文论述了各项评价指标和计算方法及要素指标的形成并指出利用５个要素指标的数据能比较全面地反映产品的环境性能。