Application of LCA as a decision-making tool for waste management systems
- 322 Downloads
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.
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.
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.
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.
KeywordsCardboard decision-making tool LCA methodology packaging plastics recycling waste management
- Ekvall T (1999): System expansion and Allocation in Life Cycle Assessment, with implications for Wastepaper Management. Department of Technical Environmental Planning, Chalmers University of Technology, Gothenburg, SwedenGoogle Scholar
- Eriksson E, Ölund G (1999): Återvinna, förbränna eller deponera? Miljöanalys av producentansvaret för plastforpakningar (Recycling, energy recovery or landfill? Environmental analysis of producer responsibility for plastic packaging), Department of Technical Environmental Planning, Chalmers University of Technology, Gothenburg, SwedenGoogle Scholar
- James KL, Grant T, Sonneveld K (2002): Stakeholder Involvement in Australian Paper and Packaging Waste Management LCA Study. Int J LCA 7 (3) 151–157Google Scholar
- Ross S, Evans D (2002): Excluding Site-Specific Data from the LCA Inventory: How This Affects Life Cycle Impact Assessment. Int J LCA 7 (3) 141–150Google Scholar
- Weidema B (1999): Some important aspects of market-based system delimitation in LCA-with a special view to avoiding allocation, in Final Report for Danish Dutch Workshop on LCA Methods, 16–17 September 1999 at CML, ed. Guinée J, Leiden, p. 33–46Google Scholar
- Rønning A, Ekvall T, Finnveden G (1995): Allocation, Technical Report No 7, LCA-NORDIC, Nordic Council of Ministers, TemaNord, 1995:502Google Scholar
- Askham C, Raadal HL, Hanssen OJ (2000): Analyse av miljøeffektivitet ved innsamling og gjenvinning av drikkekartonger, karton-gemballasje og bølgepapp (Analysis of the environmental effectiveness of collection and recycling of drink cartons, carton packaging and corrugated cardboard). Østfold Research Foundation, OR 24.00Google Scholar
- Askham, C, von Krogh L., Hanssen, O. J. (2001): Det Nytter! (It is beneficial! A 4-page brochure on the environmental benefits of recycling). Østfold Research FoundationGoogle Scholar
- Askham C, von Krogh L, Hanssen OJ (2001): Tilleggssimuleringer og datagrunnlag for en kortversjon av OR 24.00 (Additional simulations and data for a short version of OR24.00). Østfold Research Foundation, OR 07.01Google Scholar
- Ekvall T (1994): Principles for allocation at multi-output processes and cascade recycling, in Proceedings of the European Workshop on Allocation in LCA, eds. Huppes G, Schneider F, CML-S&P, Leiden, p. 91–101Google Scholar
- Wenzel H (1998): Basis of the EDIP method’s allocation model, in Environmental Assessment of products, eds. Hauschild M, Wenzel H, Vol. 2: Scientifc Background, Chapman & Hall, London, p. 541–565Google Scholar
- Borg M, Paulsen J, Trinius W (2001): Proposal of a Method for Allocation in Building-Related Environmental LCA Based on Economic Parameters. Int J LCA 6 (4) 219–230Google Scholar
- Azapagic A, Gift R (1998): Linear Programming as a Tool in Life Cycle Assessment. Int J LCA 3 (6) 305–316Google Scholar
- Heijungs R (ed.), Guinée JB, Huppes G, Lankreijer RM, Udo de Haes HA, Wegener Sleeswijk A, Ansems AMM, Eggels PG, van Duin R, Goede HP (1992): Environmental Life Cycle Assessment of Products, Backgrounds, National Reuse of Waste Research Programme (NOH). CML(Centre of Environmental Science), Leiden, The NetherlandsGoogle Scholar
- Guinée JB, Gorrée M, Heijungs R, Huppes G, Kleijn R, de Koning A, van Oers L, Sleeswijk AW, Suh S, Udo de Haes HA, de Bruijn H, van Duin R, Huijbregts MAJ, Lindeijer E, Roorda AAH, van der Ven BL, Weidema BP (2001): Life cycle assessment-An operational guide to the ISO Standards. CML (Centre of Environmental Science), Leiden, The NetherlandsGoogle Scholar
- ISO international standard 14041, 1998E (1998): Environmental Management-Life cycle assessment-Goal and scope definition and Inventory analysis. International Organisation for Standardisation (ISO), GenevaGoogle Scholar
- ISO international standard 14049/TR (1999): Environmental Management—Life cycle assessment—Examples for the application of ISO 14041. International Organisation for Standardisation (ISO), GenevaGoogle Scholar
- Rogstad T (2001): Gjenvinning: Mangel på brukt plast (Recycling: lack of used plastic). Miljøstrategi (Environmental Strategi) 4, p. 10Google Scholar
- Raadal H L, von Krogh L, Nyland CA, Hanssen OJ (2001): Summary of the report: Life Cycle Assessment and Socio-economic Cost Benefit Analyses of the Treatment of Plastic Packaging Waste from Households in Norway. Østfold Research Foundation OR.39.01Google Scholar
- Raadal HL, von Krogh L, Askham Nyland C, Hanssen, OJ (2001): Miljø- og samfunnsøkonomisk vurdering av håndtering av plastemballasje avfall fra husholdninger i hias- og drammensregionene (Environmental and socio-economic analysis of the treatment of waste from households in the Hias and Drammen regions). Østfold Research FoundationGoogle Scholar
- Raadal HL, Hanssen OJ, Rymoen E (1999): Gjenvinning av plast i Drammensregionen. Vurdering av miljø- og ressurseffektivitet i innsamling og gjenvinning av plastemballasjeavfall (Recycling of plastic in the Drammen region. Assessment of the environmental and resource efficiency of the collection and recycling of plastic packaging waste). Østfold Research Foundation, OR 17.99Google Scholar
- Raadal HL, Hanssen OJ (1999): Gjenvinning av plast i Drammensregionen. Vurdering av deponering, forbrenning og gjenvinning av plastemballasjeavfall (Recycling of plastic in the Drammen region. Assessment of landfill, energy recovery and recycling of plastic packaging waste). Ostfold Research Foundation, OR45.99Google Scholar
- Rogstad T (September 2001): Private communication. Folldal RecyclingGoogle Scholar