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1.
Dieuwertje L. Schrijvers Philippe Loubet Guido Sonnemann 《The International Journal of Life Cycle Assessment》2016,21(7):976-993
Purpose
Multifunctionality in life-cycle assessment (LCA) is solved with allocation, for which many different procedures are available. Lack of sufficient guidance and difficulties to identify the correct allocation approach cause a large number of combinations of methods to exist in scientific literature. This paper reviews allocation procedures for recycling situations, with the aim to identify a systematic approach to apply allocation.Methods
Assumptions and definitions for the most important terms related to multifunctionality and recycling in LCA are given. The most relevant allocation procedures are identified from literature. These procedures are expressed in mathematical formulas and schemes and arranged in a systematic framework based on the underlying objectives and assumptions of the procedures.Results and discussion
If the LCA goal asks for an attributional approach, multifunctionality can be solved by applying system expansion—i.e. including the co-functions in the functional unit—or partitioning. The cut-off approach is a form of partitioning, attributing all the impacts to the functional unit. If the LCA goal asks for a consequential approach, substitution is applied, for which three methods are identified: the end-of-life recycling method and the waste mining method, which are combined in the 50/50 method. We propose to merge these methods in a new formula: the market price-based substitution method. The inclusion of economic values and maintaining a strict separation between attributional and consequential LCA are considered to increase realism and consistency of the LCA method.Conclusions and perspectives
We identified the most pertinent allocation procedures—for recycling as well as co-production and energy recovery—and expressed them in mathematical formulas and schemes. Based on the underlying objectives of the allocation procedures, we positioned them in a systematic and consistent framework, relating the procedures to the LCA goal definition and an attributional or consequential approach. We identified a new substitution method that replaces the three existing methods in consequential LCA. Further research should test the validity of the systematic framework and the market price-based substitution method by means of case studies.2.
Lucia Rigamonti Mario Grosso Maria Caterina Sunseri 《The International Journal of Life Cycle Assessment》2009,14(5):411-419
Background, aim, and scope Life cycle assessment (LCA) applied to alternative waste management strategies is becoming a commonly utilised tool for decision
makers. This LCA study analyses together material and energy recovery within integrated municipal solid waste (MSW) management
systems, i.e. the recovery of materials separated with the source-separated collection of MSW and the energy recovery from
the residual waste. The final aim is to assess the energetic and environmental performance of the entire MSW management system
and, in particular, to evaluate the influence of different assumptions about recycling on the LCA results.
Materials and methods The analysis uses the method of LCA and, thus, takes into account that any recycling activity influences the environment not
only by consuming resources and releasing emissions and waste streams but also by replacing conventional products from primary
production. Different assumptions about the selection efficiencies of the collected materials and about the quantity of virgin
material substituted by the reprocessed material were made. Moreover, the analysis considers that the energy recovered from
the residual waste displaces the same quantity of energy produced in conventional power plants and boilers fuelled with fossil
fuels.
Results The analysis shows, in the expanded model of the material and energy recovering chain, that the environmental gains are higher
than the environmental impacts. However, when we reduce the selection efficiencies by 15%, the impact indicators worsen by
a percentage included between 10% and 26%. This phenomenon is even more evident when we consider a substitution ratio of 1:<1
for paper and plastic: The worsening is around 15–20% for all the impact indicators except for the global warming for which
the worsening is up to 45%.
Discussion Hypotheses about the selection efficiencies of the source-separated collected materials and about the substitution ratio have
a great influence on the LCA results. Consequently, policy makers have to be aware of the fact that the impacts of an integrated
MSW management system are highly dependent on the assumptions made in the modelling of the material recovery, as well as in
the modelling of the energy recovery.
Conclusions LCA allows to evaluate the impacts of integrated systems and how these impacts change when the assumptions made during the
modelling of the different single parts of the system are modified. Due to the significant impacts that hypotheses about material
recovery have in the results, they should be expressed in a very transparent way in the report of LCA studies, together with
the assumptions made about energy recovery.
Recommendations and perspectives The results suggest that the hypotheses about the value of the substitution ratio are very important, and the case of wood
should therefore be better analysed and a substitution ratio of 1:<1 should be used, as for paper and plastic. It seems that
the assumptions made about which material is replaced by the recycled one are very important too, and in this sense, more
research is needed about what the recycled plastic may effectively substitute, in particular the polyolefin mix. 相似文献
3.
4.
Marieke ten Hoeve Sander Bruun Irina Naroznova Camilla Lemming Jakob Magid Lars S. Jensen Charlotte Scheutz 《The International Journal of Life Cycle Assessment》2018,23(10):1950-1965
Purpose
Life cycle assessments (LCAs) that attempt to provide advice on treatment options for phosphorus (P) containing organic waste products encounter problems related to the quantification of mineral P fertilizer substitution, P loss and crop P uptake after land application. The purpose of this study was to develop a relatively easy to use life cycle inventory model, known as PLCI, that could be used to estimate these values.Methods
A life cycle inventory model for P was developed, which estimates the effect of an application of organic waste followed by ordinary fertilizer management in the modeling period. This was compared with a simulation without the initial waste application. The difference in mineral P fertilizer application (substitution), P loss and crop P uptake was then calculated and expressed as a proportion of the amount of waste applied. As an example, the effect of an initial application of mineral fertilizer, sewage sludge and ash on two farm types was simulated. These results were applied in an LCA case study of different sewage sludge treatment options.Results and discussion
Farm type influenced the P fertilizer substitution, loss and crop uptake factors. The application on an arable farm showed a substitution of 28 to 31%, relatively low P loss and a large spread in crop P uptake for the different P sources, compared with the pig farm. Application on a pig farm showed no mineral P substitution. For substitution, mineral fertilizer outperformed waste product fertilizer with a short modeling period, due to higher immediate P availability, which was not the case with a long period. The LCA case study showed that the P substitution factor had an influence on the environmental impact categories climate change and depletion of reserve-based abiotic resources while the P loss factor influenced freshwater eutrophication. Application of the P loss and substitution factors generated from the PLCI model resulted in higher environmental burdens and lower savings than using conventional factors.Conclusions
The soil P status mainly affected P substitution and loss, with the fertilizer type only having a small influence when soils had a low P status. The PLCI model can facilitate more coherent and rigorous estimates of P substitution and loss to be used in LCA studies involving application of waste products on agricultural land. This is important since P substitution and loss can have an important influence on impact categories, such as freshwater eutrophication and resource depletion.5.
Friederike Ziegler Andreas Emanuelsson John Lucas Eichelsheim Anna Flysjö Vaque Ndiaye Mikkel Thrane 《Journal of Industrial Ecology》2011,15(4):527-538
Southern pink shrimp (Penaeus notialis) are an important Senegalese export commodity. Artisanal fisheries in rivers produce 60%. Forty percent are landed in trawl fisheries at sea. The shrimp from both fisheries result in a frozen, consumer‐packed product that is exported to Europe. We applied attributional life cycle assessment (LCA) to compare the environmental impact of the two supply chains and identify improvement options. In addition to standard LCA impact categories, biological impacts of each fishery were quantified with regard to landed by‐catch, discard, seafloor impact, and size of target catch. Results for typical LCA categories include that artisanal fisheries have much lower inputs and emissions in the fishing phase than does the industrial fishery. For the product from artisanal fisheries, the main part of the impact in the standard LCA categories occurs during processing on land, mainly due to the use of heavy fuel oil and refrigerants with high global warming and ozone depletion potentials. From a biological point of view, each fishery has advantages and drawbacks, and a number of improvement options were identified. If developing countries can ensure biological sustainability of their fisheries and design the chain on land in a resource‐efficient way, long distance to markets is not an obstacle to sustainable trading of seafood products originating in artisanal fisheries. 相似文献
6.
Shelie A. Miller Stephen Moysey Benjamin Sharp Jose Alfaro 《Journal of Industrial Ecology》2013,17(3):352-362
This article presents a framework to evaluate emerging systems in life cycle assessment (LCA). Current LCA methods are effective for established systems; however, lack of data often inhibits robust analysis of future products or processes that may benefit the most from life cycle information. In many cases the life cycle inventory (LCI) of a system can change depending on its development pathway. Modeling emerging systems allows insights into probable trends and a greater understanding of the effect of future scenarios on LCA results. The proposed framework uses Bayesian probabilities to model technology adoption. The method presents a unique approach to modeling system evolution and can be used independently or within the context of an agent‐based model (ABM). LCA can be made more robust and dynamic by using this framework to couple scenario modeling with life cycle data, analyzing the effect of decision‐making patterns over time. Potential uses include examining the changing urban metabolism of growing cities, understanding the development of renewable energy technologies, identifying transformations in material flows over space and time, and forecasting industrial networks for developing products. A switchgrass‐to‐energy case demonstrates the approach. 相似文献
7.
Sheikh Moniruzzaman Moni Roksana Mahmud Karen High Michael Carbajales‐Dale 《Journal of Industrial Ecology》2020,24(1):52-63
In recent literature, prospective application of life cycle assessment (LCA) at low technology readiness levels (TRL) has gained immense interest for its potential to enable development of emerging technologies with improved environmental performances. However, limited data, uncertain functionality, scale up issues and uncertainties make it very challenging for the standard LCA guidelines to evaluate emerging technologies and requires methodological advances in the current LCA framework. In this paper, we review published literature to identify major methodological challenges and key research efforts to resolve these issues with a focus on recent developments in five major areas: cross‐study comparability, data availability and quality, scale‐up issues, uncertainty and uncertainty communication, and assessment time. We also provide a number of recommendations for future research to support the evaluation of emerging technologies at low technology readiness levels: (a) the development of a consistent framework and reporting methods for LCA of emerging technologies; (b) the integration of other tools with LCA, such as multicriteria decision analysis, risk analysis, technoeconomic analysis; and (c) the development of a data repository for emerging materials, processes, and technologies. 相似文献
8.
9.
Wesley W. Ingwersen 《Journal of Industrial Ecology》2011,15(4):550-567
Founded in thermodynamics and systems ecology, emergy evaluation is a method to associate a product with its dependencies on all upstream environmental and resource flows using a common unit of energy. Emergy is thus proposed as an indicator of aggregate resource use for life cycle assessment (LCA). An LCA of gold mining, based on an original life cycle inventory of a large gold mine in Peru, is used to demonstrate how emergy can be incorporated as an impact indicator into a process‐based LCA model. The results demonstrate the usefulness of emergy in the LCA context. The adaptation of emergy evaluation, traditionally performed outside of the LCA framework, requires changes to the conventional accounting rules and the incorporation of uncertainty estimations of the emergy conversion factors, or unit emergy values. At the same time, traditional LCA boundaries are extended to incorporate the environmental processes that provide for raw resources, including ores. The total environmental contribution to the product, doré, is dominated by mining and metallurgical processes and not the geological processes forming the gold ore. The measure of environmental contribution to 1 gram (g) of doré is 6.8E + 12 solar‐equivalent Joules (sej) and can be considered accurate within a factor of 2. These results are useful in assessing a process in light of available resources, which is essential to measuring long‐term sustainability. Comparisons are made between emergy and other measures of resource use, and recommendations are made for future incorporation of emergy into LCA that will result in greater consistency with existing life cycle inventory (LCI) databases and other LCA indicators. 相似文献
10.
John Harvey Alissa Kendall Nick Santero Thomas Van Dam In-Sung Lee Ting Wang 《The International Journal of Life Cycle Assessment》2011,16(9):944-946
Purpose
A workshop was convened on life cycle assessment (LCA) applied to pavement. The workshop’s primary goals were to establish common practices for conducting LCAs for pavements. In general, pavement LCA has been implemented without clear guidelines for modeling assumptions and reporting. This shortcoming has led to challenges in interpreting and comparing pavement LCA outcomes. 相似文献11.
Gustav Sandin Greg M. Peters Magdalena Svanström 《The International Journal of Life Cycle Assessment》2014,19(4):723-731
Purpose
The nature of end-of-life (EoL) processes is highly uncertain for constructions built today. This uncertainty is often neglected in life cycle assessments (LCAs) of construction materials. This paper tests how EoL assumptions influence LCA comparisons of two alternative roof construction elements: glue-laminated wooden beams and steel frames. The assumptions tested include the type of technology and the use of attributional or consequential modelling approaches.Methods
The study covers impact categories often considered in the construction industry: total and non-renewable primary energy demand, water depletion, global warming, eutrophication and photo-chemical oxidant creation. The following elements of the EoL processes are tested: energy source used in demolition, fuel type used for transportation to the disposal site, means of disposal and method for handling allocation problems of the EoL modelling. Two assumptions regarding technology development are tested: no development from today’s technologies and that today’s low-impact technologies have become representative for the average future technologies. For allocating environmental impacts of the waste handling to by-products (heat or recycled material), an attributional cut-off approach is compared with a consequential substitution approach. A scenario excluding all EoL processes is also considered.Results and discussion
In all comparable scenarios, glulam beams have clear environmental benefits compared to steel frames, except for in a scenario in which steel frames are recycled and today’s average steel production is substituted, in which impacts are similar. The choice of methodological approach (attributional, consequential or fully disregarding EoL processes) does not seem to influence the relative performance of the compared construction elements. In absolute terms, four factors are shown to be critical for the results: whether EoL phases are considered at all, whether recycling or incineration is assumed in the disposal of glulam beams, whether a consequential or attributional approach is used in modelling the disposal processes and whether today’s average technology or a low-impact technology is assumed for the substituted technology.Conclusions
The results suggest that EoL assumptions can be highly important for LCA comparisons of construction materials, particularly in absolute terms. Therefore, we recommend that EoL uncertainties are taken into consideration in any LCA of long-lived products. For the studied product type, LCA practitioners should particularly consider EoL assumptions regarding the means of disposal, the expected technology development of disposal processes and any substituted technology and the choice between attributional and consequential approaches. 相似文献12.
Ivan Muñoz Joan Rieradevall Xavier Domènech Cristina Gazulla 《The International Journal of Life Cycle Assessment》2006,11(5):323-334
Goal, Scope and Background The new European legislation concerning End-of-Life Vehicles (ELVs) will allow, in 2015, the landfilling of only 5% of the
average vehicle weight, which means that the automotive industry must make a great effort in order to design their products
taking into account their recyclability when they become waste. In the present work, LCA is used to assess an existing automotive
component, a plastic door panel, and to compare it with a designed-for-recycling prototype panel, based on compatible polyolefins.
Main Features A \\\'cradle to grave\\\' LCA is carried out for the panel currently produced and the prototype. The following scenarios
are analyzed for plastic waste: landfilling (current practice in Spain), energy recovery in a MSW incinerator or in a cement
kiln, and mechanical recycling.
Results and Discussion The production and use phases together contribute more than 95% in most impact indicators. When the current and prototype
products are compared, a decrease in the environmental impact appears for the prototype in the production phase and also at
end-of-life if recycling is considered with full substitution of virgin polymers. The overall impact reduction ranges from
18% in the toxicity indicators to 80% in landfill use. Energy recovery in cement kilns appears as a good alternative to recycling
in some indicators, such as landfill use or resource depletion. A sensitivity analysis is performed on the quality of recycled
plastic, and the results suggest that the benefits of recycling are substantially reduced if full substitution is not achieved.
Conclusion LCA has been shown to be a very useful tool to validate from an environmental point of view a redesigned automotive component;
in addition, it has allowed one to identify not only the benefits from increased recyclability, but also improvements in other
life cycle phases which were not previously expected.
Recommendation and Perspective From this case study several recommendations to the company have been drawn in order to design environmentally friendly components
for car interiors, and ecodesign is expected to be introduced in the company procedures.
- Glossary
ABS: Acrilonitrile-butadiene-styrene; ASR: Automobile shredder residue; DEHP: Di(ethylhexyl)phtalate; ELV: End-of-life vehicles;
EPDM: Ethylene propylene diene monomer; MSW: Municipal solid waste; MSWI: Municipal solid waste incinerator; NEDC: New European
driving cycle; PA GF: Polyamide glass fiber reinforced; PE: Polyethylene; PES: Polyester; POM: Polyoxymethylene; PP T16: Polypropylene
16% talc filled; PUR: Polyurethane; PVC: Polyvinyl chloride; TPO: Thermoplastic olefin 相似文献
13.
Trevor Zink Frank Maker Roland Geyer Rajeevan Amirtharajah Venkatesh Akella 《The International Journal of Life Cycle Assessment》2014,19(5):1099-1109
Purpose
Waste management for end-of-life (EoL) smartphones is a growing problem due to their high turnover rate and concentration of toxic chemicals. The versatility of modern smartphones presents an interesting alternative waste management strategy: repurposing. This paper investigates the environmental impact of smartphone repurposing as compared to traditional refurbishing using Life Cycle Assessment (LCA).Methods
A case study of repurposing was conducted by creating a smartphone “app” that replicates the functionality of an in-car parking meter. The environmental impacts of this prototype were quantified using waste management LCA methodology. Studied systems included three waste management options: traditional refurbishment, repurposing using battery power, and repurposing using a portable solar charger. The functional unit was defined as the EoL management of a used smartphone. Consequential system expansion was employed to account for secondary functions provided; avoided impacts from displaced primary products were included. Impacts were calculated in five impact categories. Break-even displacement rates were calculated and sensitivity to standby power consumption were assessed.Results and discussion
LCA results showed that refurbishing creates the highest environmental impacts of the three reuse routes in every impact category except ODP. High break-even displacement rates suggest that this finding is robust within a reasonable range of primary cell phone displacement. The repurposed smartphone in-car parking meter had lower impacts than the primary production parking meter. Impacts for battery-powered devices were dominated by use-phase charging electricity, whereas solar-power impacts were concentrated in manufacturing. Repurposed phones using battery power had lower impacts than those using solar power, however, standby power sensitivity analysis revealed that solar power is preferred if the battery charger is left plugged-in more than 20 % of the use period.Conclusions
Our analysis concludes that repurposing represents an environmentally preferable EoL option to refurbishing for used smartphones. The results suggest two generalizable findings. First, primary product displacement is a major factor affecting whether any EoL strategy is environmentally beneficial. The benefit depends not only on what is displaced, but also on how much displacement occurs; in general, repurposing allows freedom to target reuse opportunities with high “displacement potential.” Second, the notion that solar power is preferable to batteries is not always correct; here, the rank-order is sensitive to assumptions about user behavior. 相似文献14.
Per H Nielsen Michael Hauschild 《The International Journal of Life Cycle Assessment》1998,3(3):158-168
For the inventory analysis of environmental impacts associated with products in Life Cycle Assessment (LCA) there is a great
need for estimates of emissions from waste products disposed at municipal solid waste landfills (product specific emissions).
Since product specific emissions can not be calculated or measured directly at the landfills, they must be estimated by modeling
of landfill processes. This paper presents a landfill model based on a large number of assumptions and approximations concerning
landfill properties, waste product properties and characteristics of various kinds of environmental protection systems (e.g.
landfill gas combustion units and leachate treatment units). The model is useful for estimation of emissions from waste products
disposed in landfills and it has been made operational in the computer tool LCA-LAND presented in a following paper. In the
model, waste products are subdivided into five groups of components: general organic matter (e.g. paper), specific organic
compounds (e.g. organic solvents), inert components (e.g. PVC), metals (e.g. cadmium), and inorganic non-metals (e.g. chlorine,)
which are considered individually. The assumptions and approximations used in the model are to the extent possible scientifically
based, but where scientific information has been missing, qualified estimates have been made to fulfill the aim of a complete
tool for estimation of emissions. Due to several rough simplifications and missing links in our present understanding of landfills,
the uncertainty associated with the model is relatively high. 相似文献
15.
Goal, Scope and Background Green Productivity (GP) is a new paradigm in sustainable manufacturing where resource conservation and waste minimization
constitute the strategy in simultaneously enhancing environmental performance and productivity. This productivity approach
to the sustainability of industries requires the adoption of clean production technology and the development of appropriate
indicators and instruments to measure environmental performance in a continuous improvement strategy that focuses on the manufacturing
stage of the product life cycle. The analysis may be expanded to include the entire life cycle with increasing details on
impacts, improvement strategies and indicators.
Methods The study proposes a methodology for GP assessment that integrates the essential components of life cycle assessment (LCA)
and multicriteria decision analysis specifically the analytic hierarchy process (AHP). LCA provides a systematic and holistic
perspective for GP analysis that spans inventory, impact and improvement assessment. The AHP is utilized as a decision framework
and valuation tool for impact and improvement assessment to come up with priority weights. Indicators are derived and measured
from a streamlined LCA focused on a number of parameters within the gate-to-gate analysis to demonstrate the GP concept in
relation to resource utilization and waste minimization. An input-output approach using a suitable material balance in a scenario
analysis provides the basis of GP performance measurement.
Results and Conclusion The diagnostic model is applied on a semiconductor assembly/packaging operation. From the streamlined life cycle inventory,
impact factors were derived for water resource depletion (WRD), energy resource depletion (ERD), human toxicity-air (HTA),
human toxicity-land (HTL), human toxicity-water (HTW), aquatic ecotoxicity (ETA) and terrestrial ecotoxicity (ETT). Valuation
of impact factors using the AHP showed the high significance of ETT, HTL, WRD and ERD. This especially reflects the impact
of the industry on the solid waste problem as a result of emissions to land associated with human toxicity and ecotoxicity
effects and the intensive use of water and energy resources. Using scenario analysis, the effect of implementing a process-based
improvement technique on a product-specific operation was determined and the highest values in GP are for energy utilization,
water utilization and terrestrial ecotoxicity.
Recommendation and Perspective Expert system technology was explored in developing a diagnostic prototype that emulates how human experts diagnose green
productivity of manufacturing processes. The aim was to investigate how such a diagnosis could be performed in an intelligent
fashion that it is also easily accessible as a decision support for industries. The expert system model will provide flexibility
in testing the relationships of environmental performance and productivity parameters as well as in preserving and disseminating
valuable human expertise in GP program implementation. This is a continuing research effort that is building the knowledge
base for GP assessment. It will include case studies over a wider range or level of detail regarding the impacts and improvement
techniques and the other stages of the product life cycle. 相似文献
16.
Gurbakhash S. Bhander Thomas H. Christensen Michael Z. Hauschild 《The International Journal of Life Cycle Assessment》2010,15(4):403-416
Background, aim, and scope
The management of municipal solid waste and the associated environmental impacts are subject of growing attention in industrialized countries. European Union has recently strongly emphasized the role of LCA in its waste and resource strategies. The development of sustainable solid waste management systems applying a life cycle perspective requires readily understandable tools for modeling the life cycle impacts of waste management systems. The aim of the paper is to demonstrate the structure, functionalities, and LCA modeling capabilities of the PC-based life cycle-oriented waste management model EASEWASTE, developed at the Technical University of Denmark specifically to meet the needs of the waste system developer with the objective to evaluate the environmental performance of the various elements of existing or proposed solid waste management systems. 相似文献17.
Application of a Life Cycle Model for European Union Policy‐Driven Waste Management Decision Making in Emerging Economies
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Nemanja Stanisavljevic James W. Levis Morton A. Barlaz 《Journal of Industrial Ecology》2018,22(2):341-355
Solid waste life cycle modeling has predominantly focused on developed countries, but there are significant opportunities to assist developing and transition economies to minimize the environmental impact of solid waste management (SWM). Serbia is representative of a transition country and most (92%) of its waste is landfilled. As a Candidate European Union (EU) country, Serbia is expected to implement SWM strategies that meet EU directives. The Solid Waste Life‐Cycle Optimization Framework (SWOLF) was used to evaluate scenarios that meet EU goals by 2030. Scenarios included combinations of landfills, anaerobic digestion, composting, material recovery facilities (MRFs), waste‐to‐energy (WTE) combustion, and the use of refuse‐derived fuel in cement kilns. Each scenario was evaluated with and without separate collection of recyclables. Modeled impacts included cost, climate change, cumulative fossil energy demand, acidification, eutrophication, photochemical oxidation, total eco‐toxicity, and total human toxicity. Trade‐offs among the scenarios were evaluated because no scenario performed best in every category. In general, SWM strategies that incorporated processes that recover energy and recyclable materials performed well across categories, whereas scenarios that did not include energy recovery performed poorly. Emissions offsets attributable to energy recovery and reduced energy requirements associated with remanufacturing of recovered recyclables had the strongest influence on the results. The scenarios rankings were robust under parametric sensitivity analysis, except when the marginal electricity fuel source changed from coal to natural gas. Model results showed that the use of existing infrastructure, energy recovery, and efficient recovery of recyclables from mixed waste can reduce environmental emissions at relatively low cost. 相似文献
18.
Bo Weidema 《Journal of Industrial Ecology》2000,4(3):11-33
Abstract: In a life‐cycle assessment (LCA) involving only one of several products from the same process, how are the resource consumption and the emissions associated with this process to be partitioned and distributed over these co‐products? This is the central question in co‐product allocation, which has been one of the most controversial issues in the development of the methodology for life‐cycle assessment, as it may significantly influence or even determine the result of the assessments. In this article, it is shown that in prospective life‐cycle assessments, co‐product allocation can always be avoided by system expansion. Through a number of examples, it is demonstrated how system expansion is performed, with special emphasis on issues that earlier have been a focus of the allocation debate, such as joint production (e.g., of chlorine and sodium hydroxide, zinc and heavy metals, and electricity and heat), the handling of “near‐to‐waste” by‐products, processes simultaneously supplying services to multiple product systems, and credits for material recycling and downcycling. It is shown that all the different co‐product situations can be covered by the same theoretical model and the same practical procedure, and that it is also possible to include the traditional co‐product allocation as a special case of the presented procedure. The uncertainty aspects of the presented procedure are discussed. A comparison is made with the procedure of ISO 14041, “Life‐cycle assessment—Goal and scope definition and inventory analysis,” the international standard. 相似文献
19.
Simone Nessi Lucia Rigamonti Mario Grosso 《The International Journal of Life Cycle Assessment》2013,18(7):1358-1373
Purpose
Waste prevention has been assigned increasing attention worldwide during recent years, and it is expected to become one of the core elements of waste management planning in the near future. In this framework, this paper presents and discusses two possible LCA approaches for the evaluation of the environmental and energetic performance of municipal solid waste (MSW) management systems which include the effects of waste prevention activities.Methods
The two approaches are conceived for the comparison of waste management scenarios including waste prevention activities with baseline scenarios without waste prevention. For both of them, the functional unit is defined and the system boundaries are described with reference to different typologies of waste prevention activities identified in an extensive review. The procedure for the calculation of the LCA impacts of scenarios is also reported and an example illustrating the processes to be included in system boundaries for a specific waste prevention activity is provided.Results and discussion
The presented approaches lead to the same result in terms of difference between the LCA impacts of a waste prevention scenario and of a baseline one. However, because of the partially different upstream system boundaries, different values of the impacts of single scenarios are obtained and the application of the two approaches is more suitable in different situations and in analyses with different purposes. The methodological aspects that can complicate the applicability of the two approaches are discussed lastly.Conclusions
The environmental and energetic performance of MSW management scenarios including waste prevention activities can be evaluated with the two LCA approaches presented in this paper. They can be used for many purposes such as, among the most general, evaluating the upstream and downstream environmental consequences of implementing particular waste prevention activities in a given waste management system, complementing waste reduction indicators with LCA-based indicators and supporting with quantitative evidence the strategic and policy relevance of waste prevention. 相似文献20.
Alexandra Ewing Lanka Thabrew Debra Perrone Mark Abkowitz George Hornberger 《Journal of Industrial Ecology》2011,15(6):937-950
Establishing a comprehensive environmental footprint that indicates resource use and environmental release hotspots in both direct and indirect operations can help companies formulate impact reduction strategies as part of overall sustainability efforts. Life cycle assessment (LCA) is a useful approach for achieving these objectives. For most companies, financial data are more readily available than material and energy quantities, which suggests a hybrid LCA approach that emphasizes use of economic input‐output (EIO) LCA and process‐based energy and material flow models to frame and develop life cycle emission inventories resulting from company activities. We apply a hybrid LCA framework to an inland marine transportation company that transports bulk commodities within the United States. The analysis focuses on global warming potential, acidification, particulate matter emissions, eutrophication, ozone depletion, and water use. The results show that emissions of greenhouse gases, sulfur, and particulate matter are mainly from direct activities but that supply chain impacts are also significant, particularly in terms of water use. Hotspots were identified in the production, distribution, and use of fuel; the manufacturing, maintenance, and repair of boats and barges; food production; personnel air transport; and solid waste disposal. Results from the case study demonstrate that the aforementioned footprinting framework can provide a sufficiently reliable and comprehensive baseline for a company to formulate, measure, and monitor its efforts to reduce environmental impacts from internal and supply chain operations. 相似文献