Abstract
Purpose
Life cycle assessment (LCA) is a useful tool for quantifying the overall environmental impacts of a product, process, or service. The scientific scope and boundary definition are important to ensure the accuracy of LCA results. Defining the boundary in LCA is difficult and there are no commonly accepted scientific methods yet. The objective of this research is to present a comprehensive discussion of system boundaries in LCA and to develop an appropriate boundary delimitation method.
Methods
A product system is partitioned into the primary system and interrelated subsystems. The hierarchical relationship of flow and process is clarified by introducing flow- and process-related interventions. A system boundary curve model of the LCA is developed and the threshold rules for judging whether the system boundary satisfies the research requirement are proposed. Quantitative criteria from environmental, technical, geographical and temporal dimensions are presented to limit the boundaries of LCA. An algorithm is developed to identify an appropriate boundary by searching the process tree and evaluating the environmental impact contribution of each process while it is added into the studied system.
Results and discussion
The difference between a limited system and a theoretically complete system is presented. A case study is conducted on a color TV set to demonstrate and validate the method of boundary identification. The results showed that the overall environmental impact indicator exhibits a slow growth after a certain number of processes considered, and the gradient of the fitting curve trends to zero gradually. According to the threshold rules, a relatively accurate system boundary could be obtained.
Conclusions
It is found from this research that the system boundary curve describes the growth of life cycle impact assessment (LCIA) results as processes are added. The two threshold rules and identification methods presented can be used to identify system boundary of LCA. The case study demonstrated that the methodology presented in this paper is an effective tool for the boundary identification.
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Clift R, Frischknecht R, Huppes G et al (1998) Towards a coherent approach to life cycle inventory analysis. SETAC, Brussels
Crawford RH (2008) Validation of a hybrid life-cycle inventory analysis method. J Environ Manage 88(3):496–506
Dodbiba G, Takahashi K, Sadaki J et al (2008) The recycling of plastic wastes from discarded TV sets: comparing energy recovery with mechanical recycling in the context of life cycle assessment. J Clean Prod 16:458–470
Ekvall T, Weidema BP (2004) System boundaries and input data in consequential life cycle inventory analysis. Int J Life Cycle Assess 9(3):161–171
Environmental Protection Agency (EPA) (2006) Life cycle assessment: principles and practice. EPA/600/R-06/060. Cincinnati, OH, USA
Feng C, Ma XQ (2009) The energy consumption and environmental impacts of a color TV set in China. J Clean Prod 17(1):13–25
Finnveden G, Hauschild MZ, Ekvall T et al (2009) Recent developments in life cycle assessment. J Environ Manage 91(1):1–21
Gentil EC, Damgaard A, Hauschild M et al (2010) Models for waste life cycle assessment: review of technical assumptions. Waste Manage 30(12):2636–2648
Guinée JB (ed) (2002a) Life cycle assessment: an operational guide to the ISO standards (Eco-Efficiency in Industry and Science), part 2b. Kluwer, Dordrecht
Guinée JB (ed) (2002b) Life cycle assessment: an operational guide to the ISO standards (Eco-Efficiency in Industry and Science), part 3. Kluwer, Dordrecht
Heijungs R, Suh S (2001) The computational structure of life cycle assessment. Centre of Environmental Science, Leiden University, Holland
Heijungs R, Guinee JB, Huppes G et al (1992) Environmental life cycle assessment of products: guide and backgrounds. CML, Leiden University, Leiden
Hochschorner E, Finnveden G (2003) Evaluation of two simplified life cycle assessment methods. Int J Life Cycle Assess 8(3):119–128
International Standard Organization (ISO) (2000) Environmental management–life cycle assessment—examples of application of ISO 14041 to goal and scope definition and inventory analysis, ISO14049, BSI, ISO
International Standard Organization (ISO) (2006) Environmental management–Life cycle assessment—principles and framework. ISO14040, BSI, CEN
International Standard Organization (ISO) (2006) Environmental management–Life Cycle Assessment—requirements and guidelines, ISO 14044, BSI, CEN
Jacquemin L, Pontalier P-Y, Sablayrolles C (2012) Life cycle assessment (LCA) applied to the process industry: a review. Int J Life Cycle Assess 17(8):1028–1041
Kulkarni R, Zhang HC, Li JZ et al (2005) A framework for environmental impact assessment tools: comparison validation and application using case study of electronic products. Proc IEEE Int Symp Electron Environ, pp 210–214
Lindfors L-G, Christiansen K, Hoffman L et al (1995) Nordic guidelines on life-cycle assessment. Nord. Nordic Council of Ministers, Copenhagen
Malmodin J, Oliv L, Bergmark P (2001) Life cycle assessment of third generation (3G) wireless telecommunication systems at Ericsson. In: Proceeding of environmentally conscious design and inverse manufacturing. Proc EcoDesign 2001
Marvuglia A, Cellura M, Heijungs R (2010) Toward a solution of allocation in life cycle inventories: the use of least-squares techniques. Int J Life Cycle Assess 15(9):1020–1040
Merrild H, Damgaard A, Christensen TH (2008) Life cycle assessment of waste paper management: the importance of technology data and system boundaries in assessing recycling and incineration. Resour Conserve Recy 52(12):1391–1398
Ny H, MacDonald JP, Broman G et al (2006) Sustainability constraints as system boundaries—an approach to making life-cycle management strategic. J Ind Ecol 10(1–2):61–77
Raynolds M, Fraser R, Checkel D (2000) The relative mass-energy-economic (RMEE) method for system boundary selection. Int J Life Cycle Assess 5(1):37–46
Shrivastava P, Zhang HC, Li JZ et al (2005) Evaluating obsolete electronic products for disassembly, materials recovery, and environmental impact through a decision support system. Proc IEEE Int Symp Electron Environ, pp 221–225
Suh S, Lenzen M, Treloar GJ et al (2004) System boundary selection in life-cycle inventories using hybrid approaches. Environ Sci Technol 38(3):657–664
Tillman A-M, Ekvall T, Baumann H et al (1994) Choice of system boundaries in life cycle assessment. J Clean Prod 2(1):21–29
Todd JA, Curran MA (1999) Streamlined life-cycle assessment: a final report from the SETAC North America streamlined LCA workgroup. Society of Environmental Toxicology and Chemistry (SETAC) and SETAC Foundation for Environmental Education. Pensacola
Wenzel H, Hauschild MZ, Alting L (1997) Environmental assessment of products: Col. 1/ Methodology, tools and case studies in product development. Chapman & Hall, London
Williams E (2004) Energy intensity of computer manufacturing: hybrid assessment combining process and economic input–output methods. Environ Sci Technol 38(22):6166–6174
Yang JX, Nielsen PH (2001) Chinese life cycle impact assessment factors. J Environ Sci 13(2):205–209
Yang JX, Xu C, Wang RS (2002) Methodology and application of life cycle assessment. China Meteorological Press, Beijing (In Chinese)
Acknowledgments
The authors would like to thank National Basic Research Program of China (973 Program: 2011CB013406) for supporting the investigations.
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Li, T., Zhang, H., Liu, Z. et al. A system boundary identification method for life cycle assessment. Int J Life Cycle Assess 19, 646–660 (2014). https://doi.org/10.1007/s11367-013-0654-5
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DOI: https://doi.org/10.1007/s11367-013-0654-5