Accounting for transportation impacts in the environmental assessment of waste management plans

Background, aim, and scope  Many recent studies on waste management have described in detail the potential impacts of recycling and final treatment of municipal waste. In public debates, the attention has also been focused on the choice of final disposal technologies (e.g. landfilling vs. incineration). However, a comprehensive assessment of the impacts of waste collection and transport was still lacking. In the present study, we use LCA to evaluate the potential impact of the provincial waste management plan of Varese (northern Italy). Particular attention is devoted to the estimation of environmental impacts generated during waste transport. Materials and methods  A detailed Life Cycle Inventory was built for the transportation phase, based on primary data collected by interviewing the agencies involved in waste collection. To model the recycling and final disposal phase we relied on the BUWAL 250 database. Impacts were evaluated with the Eco-Indicator 99 method in its egalitarian formulation. Results  The results of our analysis reveal that the major potential impacts of the plan are associated with waste collection and transport. These impacts are partially compensated by reduced resource consumption through recycling and energy recovery through incineration. Discussion  The outputs of the LCIA were compared with those obtained by using other ecoindicators (Eco-Indicator 99 hierarchist and individualist, CML2, EPS2000). Although not comparable on a quantitative basis, they are qualitatively consistent. Conclusions  Neglecting the effects of collection and transport might result in a severe underestimation of the environmental impacts of a waste management system, especially as refers to depletion of fossil fuels, emission of respiratory inorganics and climate change. To reduce the environmental impact of waste management systems, an accurate optimisation of waste transport is required. Recommendations and perspectives  Effective waste management planning requires the explicit inclusion of waste collection and transport when comparing alternative management policies.     

Life cycle assessment of lightweight and end-of-life scenarios for generic compact class passenger vehicles

Goal, Scope and Background  The automotive industry has a long history in improving the environmental performance of vehicles - fuel economy and emission improvements, introduction of recycled and renewable materials, etc. The European Union also aims at improving the environmental performance of products by reducing, in particular, waste resulting from End-of-Life Vehicles (ELVs) for example. The European Commission estimates that ELVs contribute to approximately 1 % of the total waste in Europe [9]. Other European Union strategies are considering more life cycle aspects, as well as other impacts including resource or climate change. This article is summarizing the results of a European Commission funded project (LIRECAR) that aims at identifying the environmental impacts and relevance for combinations of recycling / recovery and lightweight vehicle design options over the whole life cycle of a vehicle - i.e. manufacturing, use and recycling/recovery. Three, independent and scientific LCA experts reviewed the study according to ISO 14040. From the beginning, representatives of all Life Cycle Stakeholders have been involved (European materials & supplier associations, an environmental Non-Governmental Organization, recycler’s association). Model and System Definition  The study compared 3 sets of theoretical vehicle weight scenarios: 1000 kg reference (material range of today’s end-of-life, mid-sized vehicles produced in the early 1990’s) and 2 lightweight scenarios for 100 kg and 250 kg less weight based on reference functions (in terms of comfort, safety, etc.) and a vehicle concept. The scenarios are represented by their material range of a broad range of lightweight strategies of most European car manufacturers. In parallel, three End-of-Life (EOL) scenarios are considered: EOL today and two theoretical extreme scenarios (100% recycling, respectively, 100% recovery of shredder residue fractions that are disposed of today). The technical and economical feasibility of the studied scenarios is not taken into consideration (e.g. 100% recycling is not possible). Results and Discussion  Significant differences between the various, studied weight scenarios were determined in several scenarios for the environmental categories of global warming, ozone depletion, photochemical oxidant creation (summer smog), abiotic resource depletion, and hazardous waste. However, these improvement potentials can be only realized under well defined conditions (e.g. material compositions, specific fuel reduction values and EOL credits) based on case-by-case assessments for improvements over the course of the life cycle. Looking at the studied scenarios, the relative contribution of the EOL phase represents 5% or less of the total life cycle impact for most selected impact categories and scenarios. The EOL technology variations studied do not impact significantly the considered environmental impacts. Exceptions include total waste, as long as stockpile goods (overburden, tailings and ore/coal processing residues) and EOL credits are considered. Conclusions and Recommendations  LIRECAR focuses only on lightweight/recycling, questions whereas other measures (changes in safety or comfort standards, propulsion improvements for CO₂, user behavior) are beyond the scope of the study. The conclusions are also not necessarily transferable to other vehicle concepts. However, for the question of end-of-life options, it can be concluded that LIRECAR cannot support any general recommendation and/or mandatory actions to improve recycling if lightweight is affected. Also, looking at each vehicle, no justification could be found for the general assumption that lightweight and recycling greatly influence the affected environmental dimension (Global Warming Potential or resource depletion and waste, respectively). LIRECAR showed that this general assumption is not true under all analyzed circumstances and not as significant as suggested. Further discussions and product development targets shall not focus on generic targets that define the approach/technology concerned with how to achieve environmental improvement (weight reduction [kg], recycling quota [%]), but on overall life cycle improvement). To enable this case-by-case assessment, exchanges of necessary information with suppliers are especially relevant.     

Environmental impacts of end-of-life vehicles’ management: recovery versus elimination

Purpose

In Portugal, the management of end-of-life vehicles (ELV) is set out in targets of the European Union policy for the year 2015, including 85 % recycling, 95 % recovery, and maximum of 5 % landfilling. These goals will be attained only through more efficient technologies for waste separation and recycling of shredder residues or higher rates of dismantling components. Focusing on this last alternative, a field experiment was carried out. There is potential for additional recycling/recovery of 10 %.

Methods

Three scenarios were proposed for the management of ELV wastes: (1) scenario 1 corresponds to the baseline and refers to the current management, i.e., the 10 % of ELV wastes are shredded whereby some ferrous and non-ferrous metals are recovered and the remaining fraction, called automotive shredder residues (ASR), is landfilled, (2) scenario 2 wherein the ASR fraction is incinerated with energy recovery, and (3) scenario 3 includes the additional dismantling of components for recycling and for energy recovery through solid recovered fuel, to be used as a fuel substitute in the cement industry. The environmental performance of these scenarios was quantified by using the life cycle assessment methodology. Five impact categories were assessed: abiotic resource depletion, climate change, photochemical oxidant creation, acidification, and eutrophication.

Results and discussion

Compared to the other scenarios, in scenario 1 no benefits for the impact categories of climate change and eutrophication were observed. Scenario 2 has environmental credits due to the recycling of ferrous and non-ferrous metals and benefits from energy recovery. However, this scenario has a significant impact on climate change due to emissions from thermal oxidation of polymeric materials present in the ASR fraction. A net environmental performance upgrading seems to be ensured by scenario 3, mainly due to replacing fossil fuel by solid recovered fuel.

Conclusions

The proposed additional dismantling of ELV (scenario 3) not only brings environmental benefits but also meets the European recovery and recycling targets. The associated increase of dismantling costs can be compensated by the additional recycling material revenues as well as social benefits by a rise in employment.     

BEVSIM: Battery electric vehicle sustainability impact assessment model

To achieve climate neutrality ambitions, greenhouse gas emissions from the transport sector need to be reduced by at least 90% by 2050. To support industry and policy makers on mitigating actions on climate goals it is important to holistically compare and reduce life cycle environmental impacts of road passenger vehicles. A web-based sustainability assessment tool named battery electric vehicle sustainability impact assessment model, BEVSIM, is developed to assess the environmental, circularity, and economic performance of the materials, sub-systems, parts, and individual components of battery electric vehicles and internal combustion engine vehicles. This tool allows to measure and compare impacts resulting from recycling technologies, end-of-life scenarios, and future scenarios resulting from changes in grid mixes. This paper explains the purpose of the tool, its functionality and design as well as the underlying assumptions.     

Environmental impact of thin-film GaInP/GaAs and multicrystalline silicon solar modules produced with solar electricity

Background, aim, and scope  The environmental burden of photovoltaic (PV) solar modules is currently largely determined by the cumulative input of fossil energy used for module production. However, with an increased focus on limiting the emission of CO₂ coming from fossil fuels, it is expected that renewable resources, including photovoltaics, may well become more important in producing electricity. A comparison of the environmental impacts of PV modules in case their life cycle is based on the use of PV electricity in contrast to conventional electricity can elucidate potential environmental drawbacks in an early stage of development of a solar-based economy. The goal of this paper is to show for ten impact categories the environmental consequences of replacing fossil electricity with solar electricity into the life cycle of two types of PV modules. Materials and methods  Using life cycle assessment (LCA), we evaluated the environmental impacts of two types of PV modules: a thin-film GaInP/GaAs tandem module and a multicrystalline silicon (multi-Si) module. For each of the modules, the total amount of fossil electricity required in the life cycle of the module was substituted with electricity that is generated by a corresponding PV module. The environmental impacts of the modules on the midpoint level were compared with those of the same modules in case their life cycle is based on the use of conventional electricity. The environmental impacts were assessed for Western European circumstances with an annual solar irradiation of 1000 kWh/m². For the GaInP/GaAs module, the environmental impacts of individual production steps were also analysed. Results  Environmental burdens decreased when PV electricity was applied in the life cycle of the two PV modules. The impact score reductions of the GaInP/GaAs module were up to a factor of 4.9 (global warming). The impact score reductions found for the multi-Si module were up to a factor of 2.5 (abiotic depletion and global warming). Reductions of the toxicity scores of both module types were smaller or negligible. This is caused by a decreased use of fossil fuels, on the one hand, and an increased consumption of materials for the production of the additional solar modules used for generating the required PV electricity on the other. Overall, the impact scores of the GaInP/GaAs module were reduced more than the corresponding scores of the multi-Si module. The contribution analysis of the GaInP/GaAs module production steps indicated that for global warming, the cell growth process is dominant for supply with conventional electricity, while for the solar scenario, the frame becomes dominant. Regarding freshwater aquatic ecotoxicity scores associated with the life cycle of the GaInP/GaAs module, the cell growth process is dominant for supply with conventional electricity, while the reactor system for the cell growth with the associated gas scrubbing system is dominant for the solar scenario. Discussion  There are uncertainties regarding the calculated environmental impact scores. This paper describes uncertainties associated with the used economic allocation method, and uncertainties because of missing life cycle inventory data. For the GaInP/GaAs module, it was found that the global warming impact scores range from −66% to +41%, and the freshwater aquatic ecotoxicity scores (for an infinite time horizon) range from −40% to +300% compared to the default estimates. For both impact categories, the choices associated with the allocation of gallium, with the electricity mix, with the conversion efficiency of the commercially produced GaInP/GaAs cells, and with the yield of the cell growth process are most influential. For freshwater aquatic ecotoxicity, the uncertainty concerning the lifetime of the reactor system for the GaInP/GaAs cell growth process and the gas scrubbing system is particularly relevant. Conclusions  Use of PV electricity instead of fossil electricity significantly reduces the environmental burdens of the GaInP/GaAs and the multi-Si module. The reductions of the toxicity scores, however, are smaller or negligible. Toxicity impacts of the GaInP/GaAs cells can be reduced by improvement of the yield of the cell growth process, a reduced energy demand in the cell growth process, reduction of the amount of stainless steel in the cell growth reactor system and the gas scrubbing system, and a longer lifetime of these systems. Recommendations and perspectives  Because the greenhouse gas emissions associated with the production of fossil-fuel-based electricity have an important share in global warming on a world-wide scale, switching to a more extensive use of solar power is helpful to comply with the present international legislation on the area of global warming reduction. As reductions in toxicity impact scores are smaller or negligible when fossil electricity is replaced by PV electricity, it is desirable to give specific attention to the processes which dominantly contribute to these impact categories. Furthermore, in this study, a shift in ranking of several environmental impacts of the modules has been found when PV electricity is used instead of fossil electricity. The results of a comparative LCA can thus be dependent of the electricity mix used in the life cycles of the assessed products. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Life cycle assessment comparison among different reuse intensities for industrial wooden containers

Goal, scope and background  The industrial packages sector has great importance for the transport sector in Europe. These containers, mainly wooden pallets and spools, are subject to European legislation, which promotes their reuse and recycling. This study uses life cycle assessment (LCA) to assess the environmental impact of the current management system in this sector and the benefits and drawbacks of different reuse intensities as a waste prevention strategy as opposed to the recycling option. Materials and methods  In this paper, four case studies located in Spain and representative of the wooden package sector in Europe are analysed: high reuse pallet, low reuse pallet, low reuse spool and null reuse spool. For the LCA study cases, the functional unit is that required to satisfy the transport necessity of 1,000 t by road. The impact and energy consumption assessment methods used are CML 2 Baseline 2000 and Cumulative Energy Demand. Data are mostly provided by the leading enterprises and organisations in this sector. Results  The paper provides, as a first result, a comprehensive inventory of the systems under study. Secondly, our assessment shows that the systems with higher reuse intensity show a reduction in energy and wood consumption and all the environmental impact categories except for the global warming potential from 34.0% to 81.0% in the pallet study cases and from 50.4% to 72.8% in the spool ones. This reduction is at the expense of the maintenance stage, which on the contrary increases its impact, although it is still relatively small—less than 7% in all the impact categories and flow indicators of the study cases. The highest impact stages are transport, raw material extraction and the process chain. The final disposal and maintenance stages are the lowest impact, contributing at most to less than 30% of the impact in the pallet study cases and 10% in the spool cases. Discussion  Wood consumption (WC), directly related to the number of containers needed to satisfy the functional unit, is the main factor in determining the impact of the stages, especially in the raw materials extraction and process chain stages, assuming that these are undertaken with the same technologies in all the case studies. Other variables, such as the management system, the maintenance index and the final disposal scenario, affect the impact of the remaining stages: transport, maintenance and final disposal. The global warming potential results obtained demonstrate the environmental benefits of using containers made of a renewable resource such as wood instead of using other materials, but these results are not expected to prioritise the lower reuse systems because of their better performance in this category. Conclusions  Reuse, a strategy capable of reducing the environmental impacts of the wooden container systems, is preferable to recycling, while the package maintenance tasks are still feasible. Therefore, reuse, combined with recycling as final disposal, should be encouraged to reduce the demand for natural resources and the waste generated. Recommendations  Based on these results, attention should be paid to the maintenance stage, which, being the lowest-impact one, could substantially reduce the impact of the remaining stages.     

Economic and environmental assessment of automotive plastic waste end-of-life options: Energy recovery versus chemical recycling

Most automotive plastic waste (APW) is landfilled or used in energy recovery as it is unsuitable for high-quality product mechanical recycling. Chemical recycling via pyrolysis offers a pathway toward closing the material loop by handling this heterogeneous waste and providing feedstock for producing virgin plastics. This study compares chemical recycling and energy recovery scenarios for APW regarding climate change impact and cumulative energy demand (CED), assessing potential environmental advantages. In addition, an economic assessment is conducted. In contrast to other studies, the assessments are based on pyrolysis experiments conducted with an actual waste fraction. Mass balances and product composition are reported. The experimental data is combined with literature data for up- and downstream processes for the assessment. Chemical recycling shows a lower net climate change impact (0.57 to 0.64 kg CO₂e/kg waste input) and CED (3.38 to 4.41 MJ/kg waste input) than energy recovery (climate change impact: 1.17 to 1.25 kg CO₂e/kg waste input; CED: 6.94 to 7.97 MJ/kg waste input), while energy recovery performs better economically (net processing cost of −0.05 to −0.02€/kg waste input) compared to chemical recycling (0.05 to 0.08€/kg waste input). However, chemical recycling keeps carbon in the material cycle contributing to a circular economy and reducing the dependence on fossil feedstocks. Therefore, an increasing circularity of APW through chemical recycling shows a conflict between economic and environmental objectives.     

Life cycle assessment of fuel ethanol from cassava in Thailand

Goal and Scope  A well-to-wheel analysis has been conducted for cassava-based ethanol (CE) in Thailand. The aim of the analysis is to assess the potentials of CE in the form of gasohol E10 for promoting energy security and reducing environmental impacts in comparison with conventional gasoline (CG). Method  In the LCA procedure, three separate but interrelated components: inventory analysis, characterization and interpretation were performed for the complete chain of the fuel life cycle. To compare gasohol E10 and CG, this study addressed their impact potentials per gasoline-equivalent litre, taking into account the performance difference between gasohol and gasoline in an explosion motor. Results and Discussions  The results obtained show that CE in the form of E10, along its whole life cycle, reduces certain environmental loads compared to CG. The percentage reductions relative to CG are 6.1% for fossil energy use, 6.0% for global warming potential, 6.8% for acidification, and 12.2% for nutrient enrichment. Using biomass in place of fossil fuels for process energy in the manufacture of ethanol leads to improved overall life cycle energy and environmental performance of ethanol blends relative to CG. Conclusions and Outlook  The LCA brings to light the key areas in the ethanol production cycle that researchers and technicians need to work on to maximize ethanol’s contribution to energy security and environmental sustainability ESS-Submission Editor: Mark Goedkoop (goedkoop@pre.nl)     

Using LCA to Assess Eco-design in the Automotive Sector: Case Study of a Polyolefinic Door Panel (12 pp)

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     

Life cycle assessment of Australian automotive door skins

Background, aim, and scope  Policy initiatives, such as the EU End of Life Vehicle (ELV) Directive for only 5% landfilling by 2015, are increasing the pressure for higher material recyclability rates. This is stimulating research into material alternatives and end-of-life strategies for automotive components. This study presents a Life Cycle Assessment (LCA) on an Australian automotive component, namely an exterior door skin. The functional unit for this study is one door skin set (4 exterior skins). The material alternatives are steel, which is currently used by Australian manufacturers, aluminium and glass-fiber reinforced polypropylene composite. Only the inputs and outputs relative to the door skin production, use and end-of-life phases were considered within the system boundary. Landfill, energy recovery and mechanical recycling were the end-of-life phases considered. The aim of the study is to highlight the most environmentally attractive material and end-of-life option. Methods  The LCA was performed according to the ISO 14040 standard series. All information considered in this study (use of fossil and non fossil based energy resources, water, chemicals etc.) were taken up in in-depth data. The data for the production, use and end-of-life phases of the door skin set was based upon softwares such as SimaPro and GEMIS which helped in the development of the inventory for the different end-of-life scenarios. In other cases, the inventory was developed using derivations obtained from published journals. Some data was obtained from GM-Holden and the Co-operative research Centre for Advanced Automotive Technology (AutoCRC), in Australia. In cases where data from the Australian economy was unavailable, such as the data relating to energy recovery methods, a generic data set based on European recycling companies was employed. The characterization factors used for normalization of data were taken from (Saling et. al. Int J Life Cycle Assess 7(4):203–218 2002) which detailed the method of carrying out an LCA. Results  The production phase results in maximum raw material consumption for all materials, and it is higher for metals than for the composite. Energy consumption is greatest in the use phase, with maximum consumption for steel. Aluminium consumes most energy in the production phase. Global Warming Potential (GWP) also follows a trend similar to that of energy consumption. Photo Oxidants Creation Potential (POCP) is the highest for the landfill scenario for the composite, followed by steel and aluminium. Acidification Potential (AP) is the highest for all the end-of-life scenarios of the composite. Ozone Depletion Potential (ODP) is the highest for the metals. The net water emissions are also higher for composite in comparison to metals despite high pollution in the production phases of metallic door skins. Solid wastes are higher for the metallic door skins. Discussion  The composite door skin has the lowest energy consumption in the production phase, due to the low energy requirements during the manufacturing of E-glass and its fusion with polypropylene to form sheet molding compounds. In general, the air emissions during the use phase are strongly dependent on the mass of the skins, with higher emissions for the metals than for the composite. Material recovery through recycling is the highest in metals due to efficient separation techniques, while mechanical recycling is the most efficient for the composite. The heavy steel skins produce the maximum solid wastes primarily due to higher fuel consumption. Water pollution reduction benefit is highest in case of metals, again due to the high efficiency of magnetic separation technique in the case of steel and eddy current separation technique in the case of aluminium. Material recovery in these metals reduces the amount of water needed to produce a new door skin set (water employed mainly in the ingot casting stage). Moreover, the use of heavy metals, inorganic salts and other chemicals is minimized by efficient material recovery. Conclusions  The use of the studied type of steel for the door skins is a poor environmental option in every impact category. Aluminium and composite materials should be considered to develop a more sustainable and energy efficient automobile. In particular, this LCA study shows that glass-fiber composite skins with mechanical recycling or energy recovery method could be environmentally desirable, compared to aluminium and steel skins. However, the current limit on the efficiency of recycling is the prime barrier to increasing the sustainability of composite skins. Recommendations and perspectives  The study is successful in developing a detailed LCA for the three different types of door skin materials and their respective recycling or end-of-life scenarios. The results obtained could be used for future work on an eco-efficiency portfolio for the entire car. However, there is a need for a detailed assessment of toxicity and risk potentials arising from each of the four different types of door skin sets. This will require greater communication between academia and the automotive industry to improve the quality of the LCA data. Sensitivity analysis needs to be performed such as the assessment of the impact of varying substitution factors on the life cycle of a door skin. Incorporation of door skin sets made of new biomaterials need to be accounted for as another functional unit in future LCA studies. Discussion contributions to this article from the readership would the highly welcome. The authors     

Life cycle assessment of primary magnesium production using the Pidgeon process in China

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.     

Life Cycle of Titanium Dioxide Nanoparticle Production

Life cycle impact of emissions, energy requirements, and exergetic losses are calculated for a novel process for producing titanium dioxide nanoparticles from an ilmenite feedstock. The Altairnano hydrochloride process analyzed is tailored for the production of nanoscale particles, unlike established commercial processes. The life cycle energy requirements for the production of these particles is compared with that of traditional building materials on a per unit mass basis. The environmental impact assessment and energy analysis results both emphasize the use of nonrenewable fossil fuels in the upstream life cycle. Exergy analysis shows fuel losses to be secondary to material losses, particularly in the mining of ilmenite ore. These analyses are based on the same inventory data. The main contributions of this work are to provide life cycle inventory of a nanomanufacturing process and reveal potential insights from exergy analysis that are not available from other methods.     

Recycling of aluminum can in terms of Life Cycle Inventory (LCI)

Background, Aims and Scope  Life Cycle Assessment is a technique for evaluating the environmental performance of a given product by: identifying and quantifying the energy and raw materials used in its manufacturing process, as well as the emissions of pollutants to water, soil, and air inherent in this production, use and disposal, and evaluating the environmental impact associated with the use of energy and materials and the emissions of pollutants, thus identifying opportunities to improve the system in order to optimize the environmental performance of the product. CETEA (Packaging Technology Center) has conducted a Life Cycle Assessment — LCA study of aluminum can with emphasis in life cycle inventory, collecting data for the reference years 2000–2002. The goal of this paper is to present part of this complete study, focusing the influence of aluminium recycling rate on the Life Cycle Inventory (LCI) of aluminum beverage cans in Brazil. Methods  The adopted methodology was based on the recommendations of SETAC — Society of Environmental Toxicology and Chemistry and the ISO 14040 Standard, approved by the Sub-Committee 05 of the Environmental Administration Technical Committee, TC-207, from ISO — INTERNATIONAL ORGANIZATION FOR STANDARDIZATION [1,2]. Data storage and modeling were performed by employing the PIRA Environmental Management System — PEMS [3]. Results  Taking into account the impact categories adopted in this study, it has been shown that recycling helps to improve the aluminium can environmental profile measured as LCI data. Discussion  For the transformed aluminium products, the recycling rate affects the values of the environmental parameters inventoried, but not in the same proportion, since the contribution of other stages of the product system life cycle and the recycling process remain unchanged, including the yield of this process. In general, the recycling balance is always positive due to the importance of the stages that precede the packaging production and the problem of increasing the municipal waste volume. Conclusions  The advantages of the recycling are obviously concentrated on the inventoried parameters related to the primary aluminum production and to the package disposal. The verified benefits of the recycling increase with the recycling rate enhancement. However, the effects on the inventory do not have the same magnitude of the recycling rate. This happens due to the relative contributions of the other life cycle stages, such as the transportation and sheet or can production. In agreement with the presented results, it is possible to conclude that the aluminum can recycling reduces part of the consumption of natural resources and the emissions associated to the stages previous to the production of the packaging. The parameters specifically related to the stage of aluminum production suffer reduction directly proportional to the increase of the recycling rate. In this way, all of the efforts made to increase the recycling rate will have a positive contribution to the LCI of the aluminum can. Recommendations  It is worth pointing out that LCA studies are iterative and dynamic. The data can always be refined, substituted or complemented with updated information in order to improve the representativeness of the analyzed sector. Perspectives  From this study, the aluminum sector in Brazil is able to quantify the benefits of future actions for environmental improvement of the Brazilian aluminum industry, as well as to contribute technically to Environmental Labeling initiatives regarding aluminum products. ESS-Submission Editor: Alain Dubreuil (dubreuil@nrcan.gc.ca)     

Usability of national reporting data as a reference for generic unit processes

Background, aim and scope  Renewable energy sources nowadays constitute an increasingly important issue in our society, basically because of the need for alternative sources of energy to fossil fuels that are free of CO₂ emissions and pollution and also because of other problems such as the diminution of the reserves of these fossil fuels, their increasing prices and the economic dependence of non-producers countries on those that produce fossil fuels. One of the renewable energy sources that has experienced a bigger growth over the last years is wind power, with the introduction of new wind farms all over the world and the new advances in wind power technology. Wind power produces electrical energy from the kinetic energy of the wind without producing any pollution or emissions during the conversion process. Although wind power does not produce pollution or emissions during operation, it should be considered that there is an environmental impact due to the manufacturing process of the wind turbine and the disposal process at the end of the wind turbine life cycle, and this environmental impact should be quantified in order to compare the effects of the production of energy and to analyse the possibilities of improvement of the process from that point of view. Thus, the aim of this study is to analyse the environmental impact of wind energy technology, considering the whole life cycle of the wind power system, by means of the application of the ISO 14040 standard [ISO (1998) ISO 14040. Environmental management—life cycle assessment—principles and framework. International Standard Organization, Geneva, Switzerland], which allows quantification of the overall impact of a wind turbine and each of its component parts using a Life Cycle Assessment (LCA) study. Materials and methods  The procedures, details, and results obtained are based on the application of the existing international standards of LCA. In addition, environmental details and indications of materials and energy consumption provided by the various companies related to the production of the component parts are certified by the application of the environmental management system ISO 14001 [ISO (2004) ISO 14001 Environmental management systems—requirements with guidance for use. International Standard Organization, Geneva, Switzerland]. A wind turbine is analysed during all the phases of its life cycle, from cradle to grave, by applying this methodology, taking into account all the processes related to the wind turbine: the production of its main components (through the incorporation of cut-off criteria), the transport to the wind farm, the subsequent installation, the start-up, the maintenance and the final dismantling and stripping down into waste materials and their treatment. The study has been developed in accordance with the ISO 14044 standard [ISO (2006) ISO 14044: Environmental management—life cycle assessment—requirements and guidelines. International Standard Organization, Geneva, Switzerland] currently in force. Results  The application of LCA, according to the corresponding international standards, has made it possible to determine and quantify the environmental impact associated with a wind turbine. On the basis of this data, the final environmental effect of the wind turbine after a lifespan of 20 years and its subsequent decommissioning have been studied. The environmental advantages of the generation of electricity using wind energy, that is, the reduction in emissions and contamination due to the use of a clean energy source, have also been evaluated. Discussion  This study concludes that the environmental pollution resulting from all the phases of the wind turbine (manufacture, start-up, use, and dismantling) during the whole of its lifetime is recovered in less than 1 year. Conclusions  From the developed LCA model, the important levels of contamination of certain materials can be obtained, for instance, the prepreg (a composite made by a mixture of epoxy resin and fibreglass). Furthermore, it has been concluded that it is possible to reduce the environmental effects of manufacturing and recycling processes of wind turbines and their components. Recommendations and perspectives  In order to achieve this goal in a fast and effective way, it is essential to enlist the cooperation of the different manufacturers.     

基于生命周期方法的生活垃圾资源化利用系统生态效率分析

我国生活垃圾产量大但处理能力不足,产生多种环境危害,对其资源化利用能够缓解环境压力并回收资源。为探讨生活垃圾资源化利用策略,综合生命周期评价与生命周期成本分析方法,建立生态效率模型。以天津市为例,分析和比较焚烧发电、卫生填埋-填埋气发电、与堆肥+卫生填埋3种典型生活垃圾资源化利用情景的生态效率。结果表明,堆肥+卫生填埋情景具有潜在最优生态效率;全球变暖对总环境影响贡献最大,而投资成本对经济影响贡献最大。考虑天津市生活垃圾管理现状,建议鼓励发展生活垃圾干湿组分分离及厨余垃圾堆肥的资源化利用策略。     

Influence of functional unit on the life cycle assessment of traction batteries

Goal, Scope and Background This paper describes the influence of the choice of the functional unit on the results of an environmental assessment of different battery technologies for electric and hybrid vehicles. Battery, hybrid and fuel cell electric vehicles are considered as being environmentally friendly. However, the batteries they use are sometimes said to be environmentally unfriendly. At the current state of technology different battery types can be envisaged: lead-acid, nickel-cadmium, nickel-metal hydride, lithium-ion and sodium-nickel chloride. The environmental impacts described in this paper are based on a life cycle assessment (LCA) approach. One of the first critical stages of LCA is the definition of an appropriate and specific functional unit for electric and hybrid vehicle application. Most of the known LCA studies concerning batteries were performed while choosing different functional units, although this choice can influence the final results. An adequate functional unit, allowing to compare battery technologies in their real life vehicle application should be chosen. The results of the LCA are important as they will be used as a decision support for the end-of-life vehicles directive 2000/53/EC (Official Journal of the European Communities L269/24 2000). As a consequence, a thorough analysis is required to define an appropriate functional unit for the assessment of batteries for electric vehicles. This paper discusses this issue and will mainly focus on traction batteries for electric vehicles. Main Features An overview of the different parameters to be considered in the definition of a functional unit to compare battery technologies for battery electric vehicle application is described and discussed. An LCA study is performed for the most relevant potential functional units. SimaPro 6 is used as a software tool and Eco-indicator 99 as an impact assessment method. The influence of the different selected functional units on the results (Eco-indicator Points) is discussed. The environmental impact of the different electric vehicle battery technologies is described. A sensitivity analysis illustrates the robustness of the obtained results. Results and Discussion Five main parameters are considered in each investigated functional unit: an equal depth of discharge is assumed, a relative number of batteries required during the life of the vehicle is calculated, the energy losses in the battery and the additional vehicle consumption due to the battery mass is included and the same lifetime distance target is taken into account. On the basis of the energy content, battery mass, number of cycles and vehicle autonomy three suitable functional units are defined: ‘battery packs with an identical mass’, ‘battery packs with an identical energy content’ and ‘battery packs with an identical one-charge range’. The results show that the differences in the results between these three functional units are small and imply less variation on the results than the other uncertainties inherent to LCA studies. On the other hand, the results obtained using other, less adequate, functional units can be quite different. Conclusions When performing an LCA study, it’s important to choose an appropriate functional unit. Most of the time, this choice is unambiguous. However, sometimes this choice is more complicated when different correlated parameters have to be considered, as it is the case for traction batteries. When using a realistic functional unit, the result is not influenced significantly by the choice of one out of the three suitable functional units. Additionally, the life cycle assessment allowed concluding that three electric vehicle battery technologies have a comparable environmental impact: lead-acid, nickel-cadmium and nickel-metal hydride. Lithium-ion and sodium-nickel chloride have lower environmental impacts than the three previously cited technologies when used in a typical battery electric vehicle application. Recommendations and Perspectives The article describes the need to consider all relevant parameters for the choice of a functional unit for an electric vehicle battery, as this choice can influence the conclusions. A more standardised method to define the functional unit could avoid these differences and could make it possible to compare the results of different traction battery LCA studies more easily.     

LCA application to integrated waste management planning in Gipuzkoa (Spain)

Goal, Scope and Background  Gipuzkoa is a department of the Vasque Country (Spain) with a population of about 700,000 people. By the year 2000 approximately 85% of municipal solid waste in this area was managed by landfilling, and only 15% was recycled. Due to environmental law restrictions and landfill capacity being on its limit, a planning process was initiated by the authorities. LCA was used, from an environmental point of view, to assess 7 possible scenarios arising from the draft Plan for the 2016 time horizon. Main Features  In each scenario, 9 waste flows are analysed: rest waste, paper and cardboard, glass containers, light packaging, organic-green waste, as well as industrial/commercial wood, metals and plastics, and wastewater sludge. Waste treatments range from recycling to energy recovery and landfilling. Results  Recycling of the waste flows separated at the source (paper and cardboard, glass, light packaging, organic-green waste, wood packaging, metals and plastics) results in net environmental benefits caused by the substitution of primary materials, except in water consumption. These benefits are common to the 7 different scenarios analysed. However, some inefficiencies are detected, mainly the energy consumption in collection and transport of low density materials, and water consumption in plastic recycling. The remaining flows, mixed waste and wastewater sludge, are the ones causing the major environmental impacts, by means of incineration, landfilling of partially stabilised organic material, as well as thermal drying of sludge. With the characterisation results, none of the seven scenarios can be clearly identified as the most preferable, although, due to the high recycling rates expected by the Plan, net environmental benefits are achieved in 9 out of 10 impact categories in all scenarios when integrated waste management is assessed (the sum of the 9 flows of waste). Finally, there are no relevant differences between scenarios concerning the number of treatment plants considered. Nevertheless, only the effects on transportation impacts were assessed in the LCA, since the plant construction stage was excluded from the system boundaries. Conclusions  The results of the study show the environmental importance of material recycling in waste management, although the recycling schemes assessed can be improved in some aspects. It is also important to highlight the environmental impact of incineration and landfilling of waste, as well as thermal drying of sludge using fossil fuels. One of the main findings of applying LCA to integrated waste management in Gipuzkoa is the fact that the benefits of high recycling rates can compensate for the impacts of mixed waste and wastewater sludge. Recommendations and Outlook  Although none of the scenarios can be clearly identified as the one having the best environmental performance, the authorities in Gipuzkoa now have objective information about the future scenarios, and a multidisciplinary panel could be formed in order to weight the impacts if necessary. In our opinion, LCA was successfully applied in Gipuzkoa as an environmental tool for decision making.     

Life cycle assessment of composite materials made of recycled thermoplastics combined with rice husks and cotton linters

Background, aim, and scope  The goal of this study is to analyze the environmental impact of new composite materials obtained from the combination of recycled thermoplastics (polypropylene [PP] and high-density polyethylene [HDPE]) and biodegradable waste of little economic value, namely, rice husks and recycled cotton. The environmental impact of these materials is compared to the impact of virgin PP and HDPE using life cycle assessment. Materials and methods  From-cradle-to-grave life cycle inventory studies were performed for 1 kg of each of the three new composites: PP+cotton linters, PP+rice husks, and HDPE+cotton linters. Inventory data for the recycling of thermoplastics and cotton were obtained from a number of recycling firms in Spain, while environmental data concerning rice husks were obtained mainly from one rice-processing company located in Spain. Life cycle inventory data for virgin thermoplastics were acquired from PlasticsEurope. Two different scenarios—incineration and landfilling—were considered for the assessment of disposal phase. A quantitative impact assessment was performed for four impact categories: global warming over a hundred years, nonrenewable energy depletion, acidification, and eutrophication. Results  The composites subject to analysis exhibited a significantly reduced environmental impact during the materials acquisition and processing phases compared to conventional virgin thermoplastics in all of the impact categories considered. The use of fertilizers for rice cultivation, however, impaired the results of the rice husk composite in the eutrophication category where it nevertheless outperformed its conventional counterparts. The compounding phase fundamentally implies an electric consumption. The disposal phase was analyzed with regard to emissions in the global warming category. Discussion  Composites obtained from renewable sources are still in an incipient state of development in comparison with petroleum-derived plastics. In the future, as mass production of these plastics becomes more widespread, their environmental impact can be expected to reach lower levels than those obtained in our study. The new materials exhibited adequate mechanical performance for the application analyzed (structures used in aquaculture). Conclusions  The composites subject to analysis exhibited a significantly reduced environmental impact compared to conventional virgin thermoplastics using 1 kg of material as a functional unit. Recommendations and perspectives  In accordance with the International Organization for Standardization 14044:2006 standard, it would be advisable to avoid impact allocation. This posed some difficulties, since rice husks are a coproduct of rice. Thus, some impact allocation was done in our study on the basis of economic value. It would also be advisable to take the land use impact category into consideration when performing comparative studies between composites and conventional plastics, albeit the definition of this category is currently the subject of scientific debate.     

Development of a Consumer Environmental Index and Results for Washington State Consumers

Consumer choices affect sustainability of societal systems, and state governments increasingly are interested in environmental impacts of consumption. This article describes a Consumer Environmental Index (CEI) to track the impacts of product purchase, use, and disposal and applies this initial CEI to Washington State in the United States. CEI has modules for product and service use, upstream resource extraction and manufacturing, and downstream disposal. CEI uses hybrid life cycle assessment (LCA) methods, combined with purchasing data from the Bureau of Labor Statistics (BLS) Consumer Expenditure Survey. For Washington State, when human health and ecosystem toxicity impact was assessed with the TRACI/CalTOX methods, weighted aggregate and per consumer impacts in all categories increased during the 6 years from 2000 to 2005. For impacts per real dollar spent, only the CEI's climate change component declined, falling nearly 7% between 2000 and 2005. Purchasing details in the BLS expenditure surveys enable the CEI to track environmental impact details on 700 individual categories of products and services. For example, sugar, motor oil, and wood heat appear to have serious environmental impacts, whereas recycling of paper, cardboard, and food and beverage container discards can be as effective at reducing greenhouse gas emissions as cutting vehicle fuel usage nearly in half. Such results may serve to increase understanding of environmentally effective actions to reduce climate, human health, and ecosystem impacts of consumption.     

Influence of assumptions about selection and recycling efficiencies on the LCA of integrated waste management systems

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.