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1.
Conceptión Jiménez-González Seungdo Kim Michael R. Overcash 《The International Journal of Life Cycle Assessment》2000,5(3):153-159
Life Cycle Assessment (LCA) methodology evaluates holistically the environmental consequences of a product system or activity,
by quantifying the energy and materials used, the wastes released to the environment, and assessing the environmental impacts
of those energy, materials and wastes. Despite the international focus on environmental impact and LCA, the quality of the
underlying life cycle inventory data is at least as, if not more, important than the more qualitative LCA process.
This work presents an option to generate gate-to-gate life cycle information of chemical substances, based on a transparent
methodology of chemical engineering process design (an ab initio approach). In the broader concept of a Life Cycle Inventory
(LCI), the information of each gate-to-gate module can be linked accordingly in a production chain, including the extraction
of raw materials, transportation, disposal, reuse, etc. to provide a full cradle to gate evaluation. The goal of this article
is to explain the methodology rather than to provide a tutorial on the techniques used. This methodology aims to help the
LCA practitioner to obtain a fair and transparent estimate of LCI data when the information is not readily available from
industry or literature. Results of gate-to-gate life cycle information generated using the cited methodology are presented
as a case study.
It has been our experience that both LCI and LCA information provide valuable means of understanding the net environmental
consequence of any technology. The LCI information from this methodology can be used more directly in exploring engineering
and chemistry changes to improve manufacturing processes. The LCA information can be used to set broader policy and to look
at more macro improvements for the environment. 相似文献
2.
Background, Aim and Scope The objective of this life cycle assessment (LCA) study is to develop LCA models for energy systems in order to assess the potential environmental impacts that might result from meeting energy demands in buildings. The scope of the study includes LCA models of the average electricity generation mix in the USA, a natural gas combined cycle (NGCC) power plant, a solid oxide fuel cell (SOFC) cogeneration system; a microturbine (MT) cogeneration system; an internal combustion engine (ICE) cogeneration system; and a gas boiler. Methods LCA is used to model energy systems and obtain the life cycle environmental indicators that might result when these systems are used to generate a unit energy output. The intended use of the LCA analysis is to investigate the operational characteristics of these systems while considering their potential environmental impacts to improve building design using a mixed integer linear programming (MILP) optimization model. Results The environmental impact categories chosen to assess the performance of the energy systems are global warming potential (GWP), acidification potential (AP), tropospheric ozone precursor potential (TOPP), and primary energy consumption (PE). These factors are obtained for the average electricity generation mix, the NGCC, the gas boiler, as well as for the cogeneration systems at different part load operation. The contribution of the major emissions to the emission factors is discussed. Discussion The analysis of the life cycle impact categories indicates that the electrical to thermal energy production ratio has a direct influence on the value of the life cycle PE consumption factors. Energy systems with high electrical to thermal ratios (such as the SOFC cogeneration systems and the NGCC power plant) have low PE consumption factors, whereas those with low electrical to thermal ratios (such as the MT cogeneration system) have high PE consumption factors. In the case of GWP, the values of the life cycle GWP obtained from the energy systems do not only depend on the efficiencies of the systems but also on the origins of emissions contributing to GWP. When evaluating the life cycle AP and TOPP, the types of fuel as well as the combustion characteristics of the energy systems are the main factors that influence the values of AP and TOPP. Conclusions An LCA study is performed to eraluate the life cycle emission factors of energy systems that can be used to meet the energy demand of buildings. Cogeneration systems produce utilizable thermal energy when used to meet a certain electrical demand which can make them an attractive alternative to conventional systems. The life cycle GWP, AP, TOPP and PE consumption factors are obtained for utility systems as well as cogeneration systems at different part load operation levels for the production of one kWh of energy output. Recommendations and Perspectives Although the emission factors vary for the different energy systems, they are not the only factors that influence the selection of the optimal system for building operations. The total efficiencies of the system play a significant part in the selection of the desirable technology. Other factors, such as the demand characteristics of a particular building, influence the selection of energy systems. The emission factors obtained from this LCA study are used as coefficients of decision variables in the formulation of an MILP to optimize the selection of energy systems based on environmental criteria by taking into consideration the system efficiencies, emission characteristics, part load operation, and building energy demands. Therefore, the emission factors should not be regarded as the only criteria for choosing the technology that could result in lower environmental impacts, but rather one of several factors that determine the selection of the optimum energy system. ESS-Submission Editor: Arpad Horvath (horvath@ce.berkeley.edu) 相似文献
3.
Seungdo Kim Taeyeon Hwang Michael Overcash 《The International Journal of Life Cycle Assessment》2001,6(1):35-43
The environmental performance of a color computer monitor is investigated by implementing a Life Cycle Assessment. The goal
of this study is to collect LCI data of foreground systems, to identify hot spots, and to introduce life cycle thinking at
the product design stage. Secondary data are used in the background system, and site-specific data are collected in the foreground
system.
Results show that the use phase is the most contributing phase. The operating mode and the energy saving mode during the overall
use phase contribute to the total by 59% and by 9.9%, respectively. In the production phase, the cathode ray tube assembly
process and the printed circuit board assembly process are the most contributing processes. The sensitivity analysis on the
use pattern scenario shows that the contribution ratio of the use phase ranges from 32% to 84%. Even in the home use case,
which is the best case scenario, the use phase is one of the most contributing processes to the environmental performance
of the color computer monitor. There is no significant difference in the choice of the impact assessment methodologies for
identifying the improvement opportunities.
For the external use of Life Cycle Assessment in a short-run product for the market, it is recommended that Life Cycle Assessment
should be carried out in parallel with the product design stage. It is also necessary to have a pre-existing, in-house database
for a product group in order to accelerate life cycle procedures. 相似文献
4.
Mohd Nasir Hassan Muhamad Awang Theng Lee Chong Zulina Zakaria Lim Bee Lay Norjan Yusoff Hukil Sino 《The International Journal of Life Cycle Assessment》1999,4(4):188-190
This paper discusses the application of an LCt model for solid waste management systems in Malaysia. The model was used to analyze the environmental and economic impacts of municipal waste management systems in Malaysia. In the first part of the study, the LCI model was adapted to analyze waste management systems of four selected cities: Kuala Lumpur and Penang to represent urban areas; Seremban to represent moderately urban areas and Muar to represent rural areas. The results have shown that Kuala Lumpur and Penang had greater Global Warming Potential (GWP) and the costs spent on the solid waste management were also higher as compared to that in suburban areas. In the second part of the study, a detailed evaluation was carried out by analyzing the implication of introducing incineration and composting into the solid waste management system, and the results were compared with the current system, i.e. 100 % landfilled. The relative GWP was lower for incineration, but the cost was extremely high. The results also showed that the final solid waste to be disposed to landfills and the impact due to water emissions could be reduced significantly when incineration and composting were introduced. 相似文献
5.
Allocation in Life Cycle Inventory Analysis for Joint Production 总被引:1,自引:0,他引:1
Allocation in joint production is still one of the unresolved and often discussed methodological issues in Life Cycle Inventory Analysis. Using the many years of experience of man agement sciences, a new classification scheme is proposed. It is postulated that companies perform allocation in joint production in view of optimising the products’ performance (economic and/ or environmental), which helps them to maximise their profits. Therefrom it is derived that value judgements and negotiations are inevitable. The proposed classification scheme differentiates between the number of decision-makers involved, and the type of markets for joint products. Several decision-makers have to find fair allocation factors for their commonly operated joint production, whereas individual decision-makers may choose allocation factors considering the (economic and/ or environmental) competitiveness of their joint products. Applied on the case of a small-scale gas-fuelled combined heat and power plant, the methodology proposed shows a strong dependency on the disutility function, i.e., private costs, environmental damage costs or a combination of the two. Presentation and Introduction of this set of articles see Int. J. LCA 4 (3) 175–179 (1999) 相似文献
6.
Life cycle assessment framework in agriculture on the farm level 总被引:1,自引:0,他引:1
Guido Haas Frank Wetterich Uwe Geier 《The International Journal of Life Cycle Assessment》2000,5(6):345-348
Life Cycle Assessment (LCA) is a method that can be used to assess the environmental impact of agriculture, but impact categories and the functional unit of classical LCA’s must be adapted to the specific agricultural production process. Serving as an example, the framework of a LCA of 18 grassland dairy farms covering three farming intensity levels and carried out in the Allgäu region in southern Germany is presented. By focussing on the chosen impact categories and the respective, suitable functional units, the specific needs and backgrounds of conducting an agricultural LCA are discussed in general. 相似文献
7.
Matthias Fawer Dennis Postlethwaite Hans -Jürgen Klüppel 《The International Journal of Life Cycle Assessment》1998,3(2):71-74
Zeolite A is a crystalline aluminosilicare which has been used as a builder component in laundry detergents for many years. An LCI for the production of Zeolite A (“cradle-to-factory-gate”) was carried out on behalf of the European Zeolite producers. Data from five European production sites were collected to generate an average LCI for Zeolite A. The plants covered more than 77% of the total European production in 1993 an therefore represent an average situation. The original LCI tables show detailed figures about raw material, intermediates and auxiliary material consumption. The overall energy flow for the production of I t of anhydrous Zeolite is 22400 MJ with a minimal spread of ± 5% over the individual companies. Furthermore 25 air emission parameters and 35 water emission parameters are listed and categorised with respect to their origins e.g. process dependent, transportation, thermal energy and electricity production. Each company is able to compare their individual data with the average LCI to identify any opportunities to improve production processes. In addition, this LCI of Zeolite A provides the basis for any further LCA studies of a product containing Zeolite A, including comparisons and assessments. 相似文献
8.
Jaewon Lee Hye-jin Cho Bokmoon Choi Joonyong Sung Sungyoung Lee Minjong Shin 《The International Journal of Life Cycle Assessment》2000,5(4):205-208
This study was intended to evaluate the environmental impact, and potential improvements for a typical tractor model (LT360D) of LG Machinery Co., Ltd. The life cycle of this study includes all stages from raw material acquisition up to final disposal. The eco-indicator 95 method was employed to perform an impact assessment. The result of this study is expected to represent the environmental feature of typical diesel vehicles at each life cycle stage. This study is a starting point of building life cycle inventories for typical off-road diesel tractors. With this result, environmental weak points of the tractor have been defined, and major improvement strategies have been set up to develop the ‘Green Tractor’. 相似文献
9.
This paper analyses the potential environmental impacts and economic viability of producing biodiesel from microalgae grown in ponds. A comparative Life Cycle Assessment (LCA) study of a notional production system designed for Australian conditions was conducted to compare biodiesel production from algae (with three different scenarios for carbon dioxide supplementation and two different production rates) with canola and ULS (ultra-low sulfur) diesel. Comparisons of GHG (greenhouse gas) emissions (g CO2-e/t km) and costs (¢/t km) are given. Algae GHG emissions (−27.6 to 18.2) compare very favourably with canola (35.9) and ULS diesel (81.2). Costs are not so favourable, with algae ranging from 2.2 to 4.8, compared with canola (4.2) and ULS diesel (3.8). This highlights the need for a high production rate to make algal biodiesel economically attractive. 相似文献
10.
This paper explores the use of LCA as a tool for process environmental management, thereby moving the focus from product to
process oriented analysis. The emphasis is on Improvement Assessment in which the “hot spots” in the system are targeted for
maximum environmental improvements. In this context, it is useful to use multiobjective optimisation which renders Valuation
unnecessary.
The approach is illustrated by the case study of the system processing boron ores to make five different products. The results
of Inventory Analysis and Impact Assessment are presented and discussed. In Improvement Assessment, a number of improvement
options are identified and evaluated, using system optimisation. It is shown that the site environmental performance can be
improved over current operation by an average of 20% over the whole life cycle. Thus the study demonstrates that the optimisation
approach to environmental process management may assist in identifying optimal ways to operate a process or plant from “cradle
to grave”. This may help the process industries not only to comply with legislation but also provide a framework for taking
a more proactive approach to environmental management leading to more sustainable industrial operations and practices. 相似文献
11.
Boguslaw Bieda 《The International Journal of Life Cycle Assessment》2011,16(6):503-511
Purpose
The goal of this paper is to describe the life cycle inventory (LCI) approach of energy produced by ArcelorMittal Steel Power Plant Poland (AMSPPP) in Krakow, Poland. The present LCI is representative for the reference year 2005 by application of ISO 14040: 2006. The system boundaries were labeled as gate-to-gate (it covered full process chain for energy production). Background data of inputs and outputs from the steel power plant have been inventoried as follows: consumption of energy and fuels, including: power coal (domestic), natural gas, blast furnace gas and coke oven gas, emission of air pollutants, emissions of particulate, air emissions from stockpiles, wastes, internal transport, and land use. 相似文献12.
Fawer Matthias Concannon Martin Rieber Wolfram 《The International Journal of Life Cycle Assessment》1999,4(4):207-212
Soluble alkali silicate glasses, liquids and powders are an important class of primary synthetic chemicals and are produced
in large quantities both in Europe and world-wide. They are utilised in a broad range of application fields, both industrial
and domestic, including detergents, chemical feedstocks, paper manufacture, civil engineering and adhesives. In order to establish
viable figures for the consumption of raw materials, water and energy and the emissions to air and water and solid waste generation,
the production routes for five typical commercial sodium silicate products were traced back to the extraction of the relevant
raw materials from the earth. Life Cycle Inventories for these products were compiled by EMPA St. Gallen / Switzerland on
behalf of CEES, a Sector Group of CEFIC, using the data input based on the production of 1995 from 12 West European silicate
producers covering about 93% of the total alkaline silicate production in Western Europe. 相似文献
13.
Christophe Rafenberg Mayer Eric 《The International Journal of Life Cycle Assessment》1998,3(3):131-144
On behalf of the French press group Le MONDE, four newspapers have been examined in a Life Cycle Assessment study. The products
were the newspaper actually produced and sold in 1995, two other 1995 versions with reduced amounts of unsold circulation
and an improved version manufactured under adequate management control and using paper, inks, printing plates and packaging
material with lower environmental impacts.
Results include the following
System boundaries and references are given in the paper. 相似文献
• | An improved distribution, reducing the unsold circulation by 40% and 80%, does not reduce significantly the relative effect score of the different environmental impacts because the effects of the internal management are predominant. |
• | The development of an improved version of Le MONDE depends more on managerial will than on technical decisions. |
• | The use of vegetal inks improves significantly the air quality inside the printing plant as well as the photochemical oxidant potential. |
14.
Life cycle assessment of primary magnesium production using the Pidgeon process in China 总被引:1,自引:0,他引:1
Feng Gao Zuoren Nie Zhihong Wang Xianzheng Gong Tieyong Zuo 《The International Journal of Life Cycle Assessment》2009,14(5):480-489
Background, aims, and scope China has been the largest primary magnesium producer in the world since year 2000 and is an important part of the global
magnesium supply chain. Almost all of the primary magnesium in China is produced using the Pidgeon process invented in the
1940s in Canada. The environmental problems of the primary magnesium production with the Pidgeon process have already attracted
much attention of the local government and enterprises. The main purposes of this research are to investigate the environmental
impacts of magnesium production and to determine the accumulative environmental performances of three different scenarios.
System boundary included the cradle-to-gate life cycle of magnesium production, including dolomite ore extraction, ferrosilicon
production, the Pidgeon process, transportation of materials, and emissions from thermal power plant. The life cycle assessment
(LCA) case study was performed on three different fuel use scenarios from coal as the overall fuel to two kinds of gaseous
fuels, the producer gas and coke oven gas. The burden use of gaseous fuels was also considered.
Methods The procedures, details, and results obtained are based on the application of the existing international standards of LCA,
i.e., the ISO 14040. Depletion of abiotic resources, global warming, acidification, and human toxicity were adopted as the
midpoint impact categories developed by the problem-oriented approach of CML to estimate the characterized results of the
case study. The local characterization and normalization factors of abiotic resources were used to calculate abiotic depletion
potential (ADP). The analytic hierarchy process was used to determine the weight factors. Using the Umberto version 4.0, the
emissions of dolomite ore extraction were estimated and the transportation models of the three scenarios were designed.
Results and conclusions The emissions inventory showed that both the Pidgeon process of magnesium production and the Fe–Si production were mainly
to blame for the total pollutant emissions in the life cycle of magnesium production. The characterized results indicated
that ADP, acidification potential, and human toxicity potential decreased cumulatively from scenarios 1 to 3, with the exception
of global warming potential. The final single scores indicated that the accumulative environmental performance of scenario
3 was the best compared with scenarios 1 and 2. The impact of abiotic resources depletion deserves more attention although
the types and the amount of mineral resources for Mg production are abundant in China. This study suggested that producer
gas was an alternative fuel for magnesium production rather than the coal burned directly in areas where the cost of oven
gas-produced coke is high. The utilization of “clean” energy and the reduction of greenhouse gases and acidic gases emission
were the main goals of the technological improvements and cleaner production of the magnesium industry in China.
Recommendation and perspective This paper has demonstrated that the theory and method of LCA are actually helpful for the research on the accumulative environmental
performance of primary magnesium production. Further studies with “cradle-to-cradle” scheme are recommended. Furthermore,
other energy sources used in magnesium production and the cost of energy production could be treated in further research. 相似文献
15.
Gayathri Babarenda Gamage Carol Boyle Sarah J. McLaren Jake McLaren 《The International Journal of Life Cycle Assessment》2008,13(5):401-411
Background, aims and scope The environmental aspects of companies and their products are becoming more significant in delivering competitive advantage.
Formway Furniture, a designer and manufacturer of office furniture products, is a New Zealand-based company that is committed
to sustainable development. It manufactures two models of the light, intuitive, flexible and environmental (LIFE) office chair:
one with an aluminium base and one with a glass-filled nylon (GFN) base. It was decided to undertake a life cycle assessment
(LCA) study of these two models in order to: (1) determine environmental hotspots in the life cycle of the two chairs (goal
1); (2) compare the life cycle impacts of the two chairs (goal 2); and (3) compare alternative potential waste-management
scenarios (goal 3). The study also included sensitivity analysis with respect to recycled content of aluminium in the product.
Materials and methods The LIFE chair models consist of a mix of metal and plastic components manufactured by selected Formway suppliers according
to design criteria. Hence, the research methodology included determining the specific material composition of the two chair
models and acquisition of manufacturing data from individual suppliers. These data were compiled and used in conjunction with
pre-existing data, specifically from the ecoinvent database purchased in conjunction with the SimaPro7 LCA software, to develop
the life cycle inventory of the two chair models. The life cycle stages included in the study extended from raw-material extraction
through to waste management. Impact assessment was carried out using CML 2 baseline 2000, the methodology developed by Leiden
University’s Institute for Environmental Sciences.
Results This paper presents results for global warming potential (GWP100). The study showed a significant impact contribution from
the raw-material extraction/refinement stage for both chair models; aluminium extraction and refining made the greatest contribution
to GWP100. The comparison of the two LIFE chair models showed that the model with the aluminium base had a higher GWP100 impact
than the model with the GFN base. The waste-management scenario compared the GWP100 result when (1) both chair models were
sent to landfill and (2) steel and aluminium components were recycled with the remainder of the chair sent to landfill. The
results showed that the recycling scenario contributed to a reduced GWP100 result. Since production and processing of aluminium
was found to be significant, a sensitivity analysis was carried out to determine the impact of using aluminium with different
recycled contents (0%, 34% and 100%) in both waste-management scenarios; this showed that increased use of recycled aluminium
was beneficial. The recycling at end-of-life scenarios was modelled using two different end-of-life allocation approaches,
i.e. consequential and attributional, in order to illustrate the variation in results caused by choice of allocation approach.
The results using the consequential approach showed that recycling at end-of-life was beneficial, while use of the attributional
method led to a similar GWP100 as that seen for the landfill scenario.
Discussion The results show that the main hotspot in the life cycle is the raw-material extraction/refinement stage. This can be attributed
to the extraction and processing of aluminium, a material that is energy intensive. The LIFE chair model with the aluminium
base has a higher GWP100 as it contains more aluminium. Sensitivity analysis pertaining to the recycled content of aluminium
showed that use of aluminium with high recycled content was beneficial; this is because production of recycled aluminium is
less energy intensive than production of primary aluminium. The waste-management scenario showed that recycling at end-of-life
resulted in a significantly lower GWP100 than landfilling at end-of-life. However, this result is dependent upon the modelling
approach used for recycling.
Conclusions With respect to goal 1, the study found that the raw-material extraction/refinement stage of the life cycle was a significant
factor for both LIFE chair models. This was largely due to the use of aluminium in the product. For goal 2, it was found that
the LIFE chair model with the aluminium base had a higher GWP100 than the GFN model, again due to the material content of
the two models. Results for goal 3 illustrated that recycling at end-of-life is beneficial when using a system expansion (consequential)
approach to model recycling; if an attributional ‘cut-off’ approach is used to model recycling at end-of-life, there is virtually
no difference in the results between landfilling and recycling. Sensitivity analysis pertaining to the recycled content of
aluminium showed that use of higher recycled contents leads to a lower GWP100 impact.
Recommendation and perspectives Most of the GWP100 impact was contributed during the raw-material extraction/refinement stage of the life cycle; thus, the
overall impact of both LIFE chair models may be reduced through engaging in material choice and supply chain environmental
management with respect to environmental requirements. The study identified aluminium components as a major contributor to
GWP100 for both LIFE chair models and also highlighted the sensitivity of the results to its recycled content. Thus, it is
recommended that the use of aluminium in future product designs be limited unless it is possible to use aluminium with a high
recycled content. With respect to waste management, it was found that a substantial reduction in the GWP100 impact would occur
if the chairs are recycled rather than landfilled, assuming an expanding market for aluminium. Thus, recycling the two LIFE
chair models at end-of-life is highly recommended. 相似文献
16.
Merete Høgaas Eide Thomas Ohlsson 《The International Journal of Life Cycle Assessment》1998,3(4):209-215
Two different methods for Life Cycle Inventory (LCI) applied to the dairy industry was performed at two dairies. In the simplified
method, total environmental loads from a dairy was registred and allocated to liquid milk. Energy and emissions are measured
for each process step for the detailed method. Both methods have advantages and disadvantages. The simplified method captures
all energy and emissions of dairy processing, but treats the dairy as a “black box”. The energy consumption was found to be
1, 27 MJ/1 and 2,55 MJ/1 for the two dairies. By use of the detailed method it is easy to “loose” information, and it is very
time consuming. The energy consumption was lower than for the simplified method. The environmental loads can on the other
hand be divided on the different process steps. The main conclusion is that choice of method depends on the purpose of the
LCA-study. 相似文献
17.
On the limitations of life cycle assessment and environmental systems analysis tools in general 总被引:1,自引:0,他引:1
Göran Finnveden 《The International Journal of Life Cycle Assessment》2000,5(4):229-238
The potential and limitations of life cycle assessment and environmental systems analysis tools in general are evaluated.
More specifically this is done by exploring the limits of what can be shown by LCA and other tools. This is done from several
perspectives. First, experiences from current LCAs and methodology discussions are used including a discussion on the type
of impacts typically included, quality of inventory data, methodological choices in relation to time aspects, allocation,
characterisation and weighting methods and uncertainties in describing the real world. Second, conclusions from the theory
of science are practised. It is concluded that it can in general not be shown that one product is environmentally preferable
to another one, even if this happens to be the case. This conclusion has important policy implications. If policy changes
require that it must be shown that one product is more (or less) environmentally preferable before any action can be taken,
then it is likely that no action is ever going to take place. If we want changes to be made, decisions must be taken on a
less rigid basis. It is expected that in this decision making process, LCA can be a useful input. Since it is the only tool
that can be used for product comparisons over the whole life cycle, it can not be replaced by any other tool and should be
used. Increased harmonisation of LCA methodology may increase the acceptability of chosen methods and increase the usefulness
of the tool. 相似文献
18.
Luis Bárzaga-Castellanos Ronald Neufert Gernot Kayser Bernd Markert 《The International Journal of Life Cycle Assessment》1999,4(6):329-339
The overall reduction of the environmental impact by the use of selective catalytic reduction (SCR) of nitrogen oxide emissions
in power plants was determined by strict application of ISO 14040 and ISO/DIS 14041. Special emphasis was placed on the implementation
of the total product life cycle (PLC) of ammonium molybdate as a key input material. The environmental impact was generated
by application of the life cycle assessment (LCA) concept of “ecoscarcity” and integrated in the life cycle inventory analysis
(LCI) of SCR systems. The LCI was used to generate the life cycle impact assessment (LC1A) by use of different quantitative
valuation methods. Under consideration of the overall LCIA results and the environmental protection costs of the SCR variants,
the Ecological Effectiveness of the SCR alternatives was determined. The results enable plausible conclusions with regard
to the ecological advantages of the use of deNOx catalysts in the SCR used in hard-coal fired power plants. 相似文献
19.
Callie W. Babbitt Angela S. Lindner 《The International Journal of Life Cycle Assessment》2008,13(3):202-211
Background, Goal, and Scope
Currently, only 40%, or 44.5 million metric tons, of coal combustion products (CCPs) generated in the United States each year by electric utilities are diverted from disposal in landfills or surface impoundments and recycled. Despite promising economic and environmental savings, there has been scant attention devoted to assessing life cycle impacts of CCP disposal and beneficial use. The objective of this paper is to present a life cycle inventory considering two cases of CCP management, including the stages of coal mining and preparation, coal combustion, CCP disposal, and CCP beneficial use. Six beneficial uses were considered: concrete production, structural fills, soil amendments, road construction, blasting grit and roofing granules, and wallboard.Methods
Primary data for raw material inputs and emissions of all stages considered were obtained from surveys and site visits of coal-burning utilities in Florida conducted in 2002, and secondary data were obtained from various published sources and from databases available in SimaPro 5.1 (PRé Consultants, Amersfoort, The Netherlands).Results
Results revealed that 50 percent of all CCPs produced, or 108 kg per 1,000 kg of coal combusted, are diverted for application in a beneficial use; however, the relative amounts sold by each utility is dependent on the process operating parameters, air emission control devices, and resulting quality of CCP. Diversion of 50% of all CCPs to beneficial use applications yields a decrease in the total raw materials requirements (with the exception of gravel and iron) and most emissions to air, water, and land, as compared to 100% disposal.Discussion
The greatest reduction of raw materials was attributed to replacing Portland cement with fly ash, using bottom ash as an aggregate in concrete production and road construction in place of natural materials, and substituting FGD gypsum for natural gypsum in wallboard. The use of fly ash as cementitious material in concrete also promised significant reductions in emissions, particularly the carbon dioxide that would be generated from Portland cement production. Beneficial uses of fly ash and gypsum showed reductions of emissions to water (particularly total dissolved solids) and emissions of metals to land, although these reductions were small compared to simply diverting 50% of all CCPs from landfills or surface impoundments.Conclusions
This life cycle inventory (LCI) provides the foundation for assessing the impacts of CCP disposal and beneficial use. Beneficial use of CCPs is shown here to yield reductions in raw material requirements and various emissions to all environmental compartments, with potential tangible savings to human health and the environment.Recommendations and Perspectives
Extension of this life cycle inventory to include impact assessment and sensitivity analysis will enable a determination of whether the savings in emissions reported here actually result in significant improvements in environmental and human health impacts.20.
Bente Solberg-Johansen Roland Clift Andrew Jeapes 《The International Journal of Life Cycle Assessment》1997,2(1):16-19
One of the main shortcomings of Life Cycle Assessment (LCA) when applied to the Nuclear Fuel Cycle, is that there is currently
no recognised procedure to deal with radionuclide emissions in the Impact Assessment stage. A framework which considers both
human and environmental impacts is required and a methodology which is compatible with the other impact assessment approaches
in LCA must be developed. It is important that the discussion is not only restricted to concepts, but that a working methodology
is developed which can be readily applied by LCA practitioners. A provisional method is available for assessing radiological
impacts on human health, but no consideration has been given to potential effects on the environment. A methodology is proposed
in this paper which assesses irradiation of the environment using Environmental Increments (EI) as the quality standard. This
approach is based on the same principles as for the Ecotoxicity classification group, and it represents a working methodology
which can be continuously improved as knowledge in the area increases. 相似文献