Life cycle assessment of a pyrolysis/gasification plant for hazardous paint waste

Goal, Scope and Background Life Cycle Assessment (LCA) remains an important tool in Dutch waste management policies. In 2002 the new National Waste Management Plan 2002–2012 (NWMP) became effective. It was supported by some 150 LCA studies for more than 20 different waste streams. The LCA results provided a benchmark level for new waste management technologies. Although not new, operational techniques using combined pyrolysis/gasification are still fairly rare in Europe. The goal of this study is to determine the environmental performance of the only full scale pyrolysis/gasification plant in the Netherlands and to compare it with more conventional techniques such as incineration. The results of the study support the process of obtaining environmental permits. Methods In this study we used an impact assessment method based on the guidelines described by the Centre of Environmental Science (CML) of Leiden University. The functional unit is defined as treatment of 1 ton of collected hazardous waste (paint packaging waste). Similar to the NWMP, not only normalized scores are presented but also 7 aggegated scores. All interventions from the foreground process (land use, emissions, final waste) are derived directly from the site with the exception of emissions to soil which were calculated. Interventions are accounted to each of the different waste streams by physical relations. Data from background processes are taken from the IVAM LCA database 4.0 mostly originating from the Swiss ETH96 database and adapted to the Dutch situation. Allocation was avoided by using system enlargement. The study has been peer reviewed by an external expert. Results and Discussion It was possible to determine an environmental performance for the pyrolysis/ gasification of paint packaging waste. The Life Cycle Inventory was mainly hampered by the uncertainty occurred with estimated air emissions. Here several assumptions had to be made because several waste inputs and two waste treatment installations profit from one flue gas cleaning treatment thus making it difficult to allocate the emission values from the flue gasses. Compared to incineration in a rotary kiln, pyrolysis/gasification of hazardous waste showed better scores for most of the considered impact categories. Only for the impact categories biodiversity and life support the incineration option proved favorable due to a lower land use. Several impact categories had significant influence on the conclusions: acidification, global warming potential, human toxicity and terrestrial ecotoxicity. The first three are related to a better energy efficiency for pyrolysis/gasification leading to less fossil energy consumption. Terrestrial ecotoxicity in this case is related to specific emissions of mercury and chromium (III). A sensitivity analysis has been performed as well. It was found that the environmental performance of the gasification technique is sensitive to the energy efficiency that can be reached as well as the choice for the avoided fossil energy source. In this study a conservative choice for diesel oil was made whereas a choice for heavy or light fuel oil would further improve the environmental profile. Conclusions Gasification of hazardous waste has a better environmental performance compared to the traditional incineration in rotary kilns mainly due to the high energy efficiency. As was determined by sensitivity analysis the differences in environmental performance are significant. Improvement options for a better performance are a decrease of process emissions (especially mercury) and a further improvement of the energy balance by decreasing the electricity consumption for shredders and oxygen consumption or making more use of green electricity. Recommendations and Perspectives Although the life cycle inventory was sufficiently complete, still some assumptions had to be made in order to establish sound mass balances on the level of individual components and substances. The data on input of waste and output of emissions and final waste were not compatible. It was recommended that companies put more emphasis on data storage accounted to particular waste streams. This is even more relevant since more companies in the future are expected to include life cycle impacts in their environmental performance.     

Life cycle assessment evaluation of green product labeling systems for residential construction

Purpose

Life cycle assessment (LCA) is a tool that can be utilized to holistically evaluate novel trends in the construction industry and the associated environmental impacts. Green labels are awarded by several organizations based on single or multiple attributes. The use of multi-criteria labels is a good start to the labeling process as opposed to single criteria labels that ignore a majority of impacts from products. Life cycle thinking, in theory, has the potential to improve the environmental impacts of labeling systems. However, LCA databases currently are lacking in detailed information about products or sometimes provide conflicting information.

Method

This study compares generic and green-labeled carpets, paints, and linoleum flooring using the Building for Environmental and Economic Sustainability (BEES) LCA database. The results from these comparisons are not intuitive and are contradictory in several impact categories with respect to the greenness of the product. Other data sources such as environmental product declarations and ecoinvent are also compared with the BEES data to compare the results and display the disparity in the databases.

Results

This study shows that partial LCAs focused on the production and transportation phase help in identifying improvements in the product itself and improving the manufacturing process but the results are uncertain and dependent upon the source or database. Inconsistencies in the data and missing categories add to the ambiguity in LCA results.

Conclusions

While life cycle thinking in concept can improve the green labeling systems available, LCA data is lacking. Therefore, LCA data and tools need to improve to support and enable market trends.     

Including the use phase in LCA of floor coverings

The results from two previously published case studies were used to assess the importance of use-related emissions from building materials in a life cycle perspective. The first study was an LCA study of linoleum, vinyl flooring, and solid wood flooring, while the second study examined the Volatile Organic Compounds (VOCs) emitted by these floorings. For linoleum and vinyl flooring, the emitted amounts for the use phase are of much the same magnitude as those emitted in the rest of the life cycle, but in the case of solid wood flooring the emissions of the use phase far exceed those of the remaining life cycle. The ranking of the selected floorings in the LCA study did not change when the impact of the use phase was also considered. This study recommends that LCAs should not neglect flooring-related emissions in the use phase when assessing regional and global environmental effects.     

The environmental impacts of operating an Antarctic research station

We present a life cycle assessment (LCA) of the operation of Casey Station in Antarctica. The LCA included quantifying material and energy flows, modeling of elementary flows, and subsequent environmental impacts. Environmental impacts were dominated by emissions associated with freight operations and electricity cogeneration. A participatory design approach was used to identify options to reduce environmental impacts, which included improving freight efficiency, reducing the temperature setpoint of the living quarters, and installing alternative energy systems. These options were then assessed using LCA, and have the potential to reduce environmental impacts by between 2% and 19.1%, depending on the environmental indicator.     

Environmental Evaluation of Different Treatment Processes for Sludge from Urban Wastewater Treatments: Anaerobic Digestion versus Thermal Processes (10 pp)

Background, Aims and Scope Huge amounts of sewage sludge, that need to be handled, are generated all around the world from wastewater treatment plants and its management in an economically and environmentally acceptable way has become a matter of increasing importance during the last few years. In this paper, we make use of Life Cycle Assessment (LCA) to compare biological and thermal processes, that is to say, anaerobic digestion versus pyrolysis and incineration. This paper will complete the analysis performed in a wastewater treatment plant, where sludge post-treatment was identified as one of the main contributors to the environmental impact on the global system. Methods LCA is a tool for evaluating the environmental performance of goods as well as processes or services (collectively termed products). ISO 14040 defines LCA as a compilation and evaluation of the inputs, outputs and the potential environmental impacts of a system throughout its life cycle: from the production of raw materials to the disposal of the waste generated. In this study, data relating to the actual scenario from an existent wastewater treatment plant were considered. Both bibliographical and real data from existing facilities were used for the thermal processes proposed. The Centre of Environmental Science (CML) of Leiden University's methodology was chosen to quantify the potential environmental impacts associated with the different scenarios under study. The software SimaPro 5.1 was used and CML factors (updated in 2002) were chosen for characterisation and normalisation stages. Results and Discussion In a previous study, sewage sludge was found to be a critical point in the environmental performance of a wastewater treatment plant, so different alternatives have been tackled here. Anaerobic digestion followed by land application of pasty sludge comprises both energy recovery and nutrient recovery. Other thermal processes, such as incineration or pyrolysis, allow energy recovery (both electrical and thermal) and, although nutrients are lost, new co-products are produced (tar and char at pyrolysis). Here, the most adverse case (that is to say, the total amount of heavy metals is supposed to be released from the sludge and reach the environment) was applied to consider the most negative impact due to sludge spreading in agricultural soils; so more research is required in order to establish the precise amount of heavy metals that is effectively uptaken by the plants and crops as well as the amount that is transferred to another phase as a leachate. Thermal processes are presented here as a good option to recover energy from the sludge; although the value of nutrients is lost. Tar and char, co-products from pyrolysis, are good examples that were evaluated here, recycling of bottom ashes from sludge incineration or manufacture of ceramic materials from sludge are other options to be studied in the near future. Conclusion During the last few years, several opinions have been declared in favour of land application, incineration or pyrolysis, but many voices have also spoken out against each one. To obtain general conclusions for an overall comparison of different post-treatment of urban wastewater sludge is not easy as there are many contradictory aspects. The most effective utilisation of sewage sludge implies both energy and material re-use, but this is not always possible. Nevertheless, we think that land application of digested sludge is an acceptable option, probably not the best but at least a good one, for sludge treatment as long as efforts are focused on the minimisation of heavy metal content in the final cake.     

Sensitivity analysis as a tool to extend the applicability of LCA findings

Purpose

Life cycle assessment (LCA) results are often used to communicate the environmental impacts of products and measure environmental performance for comparison between different options on the market. Sensitivity analyses are a routine part of LCA but often used with a narrow focus. In a case study on foodstuff packaging, the environmental performance of two food cartons in comparison with competing packaging solutions, i.e. food cartons, glass jars, steel cans, plastic pots and retortable pouches, was examined. Furthermore, the benefits of additional sensitivity analyses as a tool to model country-specific conditions to extend the applicability of LCA findings across a number of systems were evaluated.

Methods

A cradle-to-grave LCA in compliance with ISO standards 14040 and 14044 for the European market (EU27?+?2) was performed. The study was accompanied by a critical review process. The choice of the analysed packaging systems was made according to the European market share. Relevant processes were modelled with primary input data wherever possible; otherwise, average data from public LCI databases were applied. A wide range of environmental impact categories were covered: Climate Change, Ozone Depletion Potential, Summer Smog, Acidification, Eutrophication, Human Toxicity: PM10 and Abiotic Resource Depletion. To comply with ISO standards, a sensitivity analysis on allocation was performed. In addition, sensitivity analyses on recycling rates were included.

Results and discussion

The primary environmental impacts for both food cartons arose from base material production for primary packaging. The environmental performance of the food cartons compared favourably with all competing systems for virtually all examined impact categories, primarily due to the fact that primary packaging materials for food cartons are derived from renewable resources. The additional sensitivity analyses quantifying the influence of end-of-life management did not change overall results yet revealed trajectories that could be indicative of trends in a range of different settings from no to complete recycling. Thus, the additional sensitivity analyses revealed a robust result that may be informative in circumstances that depart from European settings.

Conclusions

Both food cartons show a superior performance in comparison with alternatives. The sensitivity analyses on recycling rates confirm this result even with very low or high quotas applied. These analyses provide valuable information on how different parameters depending on different geographic scopes may influence the overall results. Future LCA work would benefit from low-effort additional sensitivity analyses to broaden applicability of results and examine the robustness of findings.

     

Role of LCA in the design of research and development (R&D) of novel processes subject to IPPC and BAT

Establishing BAT (Best Available Techniques) for processes subject to IPPC is a new barrier and one that processes in the development stage need to be aware of. For multi-functional processes, the sectorial approach adopted under IPPC (Integrated Pollution Prevention and Control) increases the potential problems. Life Cycle Assessment (LCA) is an established tool to assist establishing BAT but is difficult to apply in its full form at the Research and Development (R&D) stage. A review of LCA in the context of a case study, the Trefoil kiln process, concludes that it has the flexibility to cope with multi-functionality and that use of key environmental issues and key indicators could overcome the informational gaps. Environmental burdens can be presented appropriately provided the research identifies appropriate allocation methods. The use of LCA thinking provided useful insight on the content of the research programme.     

Functional unit influence on building life cycle assessment

Purpose

The building sector is one of the most relevant sectors in terms of environmental impact. Different functional units (FUs) can be used in life cycle assessment (LCA) studies for a variety of purposes. This paper aimed to present different FUs used in the LCA of buildings and evaluate the influence of FU choice and setting in comparative studies.

Methods

As an example, we compared the “cradle to grave” environmental performance of four typical Brazilian residential buildings with different construction typologies, i.e., multi-dwelling and single dwelling, each with high and basic standards. We chose three types of FU for comparison: a dwelling with defined lifetime and occupancy parameters, an area of 1 m² of dwelling over a year period, and the accommodation of an occupant person of the dwelling over a day.

Results and discussion

The FU choice was found to bias the results considerably. As expected, the largest global warming indicator (GWi) values per dwelling unit and occupant were identified for the high standard dwellings. However, when measured per square meter, lower standard dwellings presented the largest GWi values. This was caused by the greater concentration of people per square meter in smaller area dwellings, resulting in larger water and energy consumption per square meter. The sensitivity analysis of FU variables such as lifetime and occupancy showed the GWi contribution of the infrastructure more relevant compared with the operation in high and basic standard dwellings. The definition of lifetime and occupancy parameters is key to avoid bias and to reduce uncertainty of the results when performing a comparison of dwelling environmental performances.

Conclusions

This paper highlights the need for adequate choice and setting of FU to support intended decision-making in LCA studies of the building sector. The use of at least two FUs presented a broader picture of building performance, helping to guide effective environmental optimization efforts from different approaches and levels of analysis. Information regarding space, time, and service dimensions should be either included in the FU setting or provided in the building LCA study to allow adjustment of the results for subsequent comparison.

     

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。     

Life cycle assessment standards

The newly emerging LCA standards provide an opportunity to review and improve upon the current LCA methodology. As more industrial practitioners enter the arena, the opportunity arises to not only demand environmental improvement from industrial service and product providers but also to fill LCA data gaps. A framework is suggested for improvement in the current LCA framework that focuses on the business relationships of the industrial practitioner. The framework seeks to promote environmental improvement from industrial sectors through the identification of state-of-the-art technologies used throughout a life cycle. Basing LCAs on the best performers in an industry will create a market for a high level of environmental performance, disperse the responsibility of inventory data gathering, and improve upon the advancements already anticipated through the widespread application of LCA.     

Life cycle assessment of a waste lubricant oil management system

Purpose

This paper compares 16 waste lubricant oil (WLO) systems (15 management alternatives and a system in use in Portugal) using a life cycle assessment (LCA). The alternatives tested use various mild processing techniques and recovery options: recycling during expanded clay production, recycling and electric energy production, re-refining, energy recovery during cement production, and energy recovery during expanded clay production.

Methods

The proposed 15 alternatives and the actual present day situation were analyzed using LCA software UMBERTO 5.5, applied to eight environmental impact categories. The LCA included an expansion system to accommodate co-products.

Results

The results show that mild processing with low liquid gas fuel consumption and re-refining is the best option to manage WLO with regard to abiotic depletion, eutrophication, global warming, and human toxicity environmental impacts. A further environmental option is to treat the WLO using the same mild processing technique, but then send it to expanded clay recycling to be used as a fuel in expanded clay production, as this is the best option regarding freshwater sedimental ecotoxicity, freshwater aquatic ecotoxicity, and acidification.

Conclusions

It is recommended that there is a shift away from recycling and electric energy production. Although sensitivity analysis shows re-refining and energy recovery in expanded clay production are sensitive to unit location and substituted products emission factors, the LCA analysis as a whole shows that both options are good recovery options; re-refining is the preferable option because it is closer to the New Waste Framework Directive waste hierarchy principle.     

Environmental Impact and Added Value in Forestry Operations in Norway

The forestry sector is experiencing an increasing demand for documentation about its environmental performance. Previous studies have revealed large differences in environmental impact caused by forestry operations, mainly due to differences in location and forestry practice. Reliable information on environmental performance for forestry operations in different regions is thus important. This article presents a case study of forestry operations in Norway. Environmental impact and value added of selected operations were assessed. This was done with a hybrid life cycle assessment (LCA) approach. Main results, including a sensitivity analysis, are presented for a set of four impact categories. The production chain assessed included all processes from seedling production to the delivery of logs to a downstream user. The environmental impact was mainly caused by logging, transport by forwarders, and transport by truck. These three operations were responsible for approximately 85% of the total environmental impact. The contribution to value added and total costs were more evenly distributed among the processes in the value chain. The sensitivity analysis revealed that the difference in environmental impact between the worst case scenario and the best case scenario was more than a factor of 4. The single most important process was the transport distance from the timber pile in the forest to the downstream user. The results show that the environmental impact from forestry operations in boreal forests was probably underreported in earlier studies.     

Evaluation of water services system through LCA. A case study for Iasi City,Romania

Purpose

The main objective of this paper is to analyse through life cycle assessment (LCA), the entire water services system in Iasi City (Romania): a representative city for the problems faced by the water services sector in Romania. Furthermore, the study is aimed at demonstrating the usefulness of the LCA approach as a support instrument for water resources management.

Methods

The life cycle inventory (LCI) of the Iasi water system was organized considering the water system components, as well as their function related to the water use life cycle: before the tap system as production phase (water abstraction, transport, treatment and distribution) and after the tap section as post-use phase (wastewater collection, treatment and discharge). The foreground data describing the LCI processes were provided directly by the company operating the Iasi water system, while the data for the background processes were sourced or selected from Ecoinvent 2.0 database. The assessment considers the quantification of environmental impacts (according to the CML 2000 baseline and Ecological Scarcity 2006 methodologies) of water supply (abstraction, treatment and distribution) and wastewater disposal (collection and treatment) relative to 1 m³ of tap water.

Results and discussion

For this given system, the results have pointed out that the before the tap system generates higher impacts than the after tap system, mainly due to the energetic effort needed for water supply and the fairly high water losses in the distribution system. However, the after the tap system, specifically the discharge of treated wastewater is still responsible for many of the water-related impact such as Eutrophication (when using CML) or Emissions to surface waters (when using the Ecological Scarcity method). Apart from the LCA approach, this study presents several scenarios for the improvement of the environmental performance of the water services, such as: changing between water sources, improving the distribution system and upgrading the wastewater treatment plant.

Conclusions

This study has demonstrated the usefulness of LCA to describe, compare and predict the environmental performance of complex water services systems (and all its components). The results have provided a reference case for the environmental profile of Iasi city water system, and have enabled the identification of its improvement alternatives. Also, this study, which represents a premiere for Romania, has opened future research directions which may include the development perspectives of the Iasi water services system, as well as improvements of LCIA methodologies to better represent the local specific water-related impacts.     

A method for improving Centre for Environmental Studies (CML) characterisation factors for metal (eco)toxicity — the case of zinc gutters and downpipes

Background, aim and scope  

The environmental impact of building products made from heavy metals has been a topic of discussion for some years. This was fuelled by results of life cycle assessments (LCAs), where the emission of heavy metals strongly effected the results. An issue was that the characterisation factors of the Centre for Environmental Studies (CML) 2000 life cycle impact assessment (LCIA) methodology put too much emphasis on the impact of metal emissions. We adjusted Zn characterisation factors according to the most recent insights in the ecotoxicity of zinc and applied them in an LCA using zinc gutters and downpipes as an example.     

6th SETAC-Europe Meeting: LCA — Selected Papers

A study of industry’s use of LCA has been performed as a special analysis of the Business Environmental Barometer (B.E.B.). The B.E.B. is an international questionnaire survey on industry’s environmental management practices (LCA included), repeated every two years. The first round in 1993 included the Nordic countries. The 1997 round will include eight European countries. This analysis intends to describe industry’s LCA use as such (e.g. active industrial sectors, applications, changes over time) and differences between companies working with LCA and those not working with LCA. The survey indicates that industry is in the process of internalising LCA knowledge, although most companies are still in the learning phase. LCA companies have more developed environmental management systems than non-LCA companies. A company’s LCA use seems to be a competitor-driven activity, judging from LCA distribution among industrial sectors.     

Do wood-based panels made with agro-industrial residues provide environmentally benign alternatives? An LCA case study of sugarcane bagasse addition to particle board manufacturing

Purpose

Sugarcane bagasse is one of the main agro-industrial residues which can be used to produce wood-based panels. However, more investigations related to its environmental performance assessment are needed, focusing on questions such as: Does it provide environmental benefits? What are its main environmental impacts? Could it substitute wood as raw material? Accordingly, this paper presents a life cycle assessment (LCA) study of particle board manufactured with sugarcane bagasse residues.

Methods

The cradle-to-gate assessment of 1 m³ of particle board made with sugarcane bagasse (PSB) considered three main subsystems: bagasse generation, bagasse distribution, and PSB production. For the inventory of PSB, dataset from two previous LCA studies related to the conventional particle board production and the ethanol life cycle for the Brazilian context were used. The allocation criterion for the bagasse generation subsystem was 9.08 % (economic base). The potential environmental impact phase was assessed by applying the CML and USEtox methods. PSB was compared with the conventional particle board manufactured in Brazil by the categories of the CML and USETox, and including land use indicators. Finally, two scenarios were analyzed to evaluate the influence of the allocation criteria and the consumption of sugarcane bagasse.

Results and discussion

All hotspots identified by CML and USETox methods are mainly related to the PSB production subsystem (24–100 % of impacts) due to heavy fuel oil, electricity, and urea-formaldehyde resin supply chain. The bagasse generation subsystem was more relevant to the eutrophication category (75 % of impacts). The bagasse distribution subsystem was not relevant because the impacts on all categories were lower than 1 %. PSB can substitute the conventional particle board mainly because of its lower contribution to abiotic depletion and ecotoxicity. Regarding land use impacts, PSB showed lower values according to all indicators (38–40 % of all impacts), which is explained by the lower demand for land occupation in comparison to that of the traditional particle board.

Conclusions

PSB can replace the traditional particle board due to its better environmental performance. The analysis of the economic allocation criterion was relevant only for the EP category, being important to reduce diesel and N-based fertilizers use during sugarcane cultivation. Regarding the influence of the sugarcane bagasse consumption, it is suggested that the sugarcane bagasse be mixed up to 75 % during particle board manufacturing so that good quality properties and environmental performance of panels can be provided.     

A comprehensive approach towards product and organisation related environmental management tools

The international standardisation of Environmental Management (EM) is documented by the ISO 14000 series. Within this series a number of Environmental Management tools are treated. Therefore, it can be seen as a “toolbox” which offers several options for sound Environmental Management practices in organisations. However, a number of questions remain because they are not treated by the standards themselves. Some examples are which of the tools should be applied to what kind of Environmental Management problem or what are the synergisms and antagonisms between these tools. To illustrate the importance of a comprehensive choice and a compatible approach towards EM-tools, Life Cycle Assessment (ISO 14040 series) is discussed in the context of Environmental Management Systems (ISO 14001). The focus of ISO 14001 are organisations, while LCA deals with products or processes. In principle, they are not compatible, since the life-cycle approach analyses one production chain from “cradle to grave” or even back to the cradle, while a management system according to ISO 14001 analyses organisations, i.e. a number of product chains, from “gate to gate”. LCAs, however, could be compiled by aggregating several “gate to gate” energy and material balances of companies. LCA can assist in prioritising and achieving the objectives of an EM-System. LCA can also help to understand the environmental impact of organisations and what share of their overall environmental burden is produced “inside the gates” or “outside the gates”, respectively.     

Continent-specific Intake Fractions and Characterization Factors for Toxic Emissions: Does it make a Difference?

Goal and Scope The goal of this study is to explore the potentials and limitations of using LCA as the basis for setting ecolabelling criteria in developing countries. The practicality of using LCA for this purpose, as required by ISO 14020, has been criticised as lacking in transparency and scientific rigour. Furthermore, ecolabelling is not widespread in developing countries. The application of LCA has therefore been illustrated by using the specific case of shrimp aquaculture in Thailand, as a basis for ecolabelling criteria for a typical product intended for export from a developing country. Method For the LCA case study, the functional unit is the standard consumer-package size, containing 1.8 kg of frozen shrimp produced by conventional intensive aquaculture in Thailand, subject to an appropriate environmental management system. The impact assessment method used in this study is CML 2 Baseline 2000. Results According to the results from the LCA study, farming appears to be the key life cycle stage generating the most significant environmental impacts: abiotic depletion and global warming, which arise mainly from the use of energy; and eutrophication caused by wastewater discharged from the shrimp ponds. It is possible to cover these impacts by quantitative ecolabelling criteria. Other important impacts could not be quantified by the LCA: depletion of wild shrimp broodstock, impacts of trawling on marine biodiversity and the choice of suitable farm sites. These impacts, which are also related to the farming stage, must be covered by 'hurdle criteria'. Conclusions and recommendations. For the present case, LCA provides a basis for quantifying a number of important ecolabelling criteria related to the use of abiotic resources and to emissions. Other important issues, connected with the use of biotic natural resources and land, are not quantifiable by current LCA methodology, but were also revealed and clarified by using an LCA framework for the analysis. Thus, focussing the assessment on life cycle considerations, as required by ISO 14024, was effective in identifying all key environmental issues. In the light of this case study, main limitations and barriers associated with the application of LCA to setting ecolabelling criteria particularly in developing countries are discussed, including recommendations on how to overcome them.     

Life cycle assessment of the environmental influence of wooden and concrete utility poles based on service lifetime

Purpose

Many applications of life cycle assessment do not consider the variability of the service lifetime of different structures, and this may be a relevant factor in an environmental impact assessment. This paper aims to determine the influence of the service lifetime on the potential environmental impacts of wooden and concrete poles in the electricity distribution system.

Methods

The estimation of service lifetime was conducted using the factorial method. The life cycle assessment was applied using SimaPro software and considered the entire life cycle of utility poles, from the extraction of raw materials to the final disposal. Then, an evaluation of the environmental impacts using the CML IA baseline method was performed. The study included the analysis of uncertainty using the Monte Carlo method.

Results and discussion

In general, the wooden poles had a lower potential environmental impact compared to the concrete poles. The result of the sensitivity analysis considering the variability of the chromated copper arsenate wood preservative retention rate suggests that the frequency of maintenance affects the service lifetime. Often, the comparison of products in the LCA perspective is carried out by considering similar useful lifetime services for the different alternatives, and this study shows that the environmental performance of products or services is directly proportional to the lifetime. It is a crucial parameter that has to be clarified in order to reduce uncertainty in the results.

Conclusions

Thus, some factors such as material quality, design adjustments and routine maintenance extend the service lifetime of a product or process and are shown to be effective ways to reduce environmental impacts. Therefore, the service lifetime has a significant influence on the development of the life cycle assessment. Comparative LCA studies are often sensitive to parameters that may even change the ranking of selected impact categories. All in all, from the sensitivity analysis highlighted in this study, the variability of lifetime service has proven to be one of the most prominent factors influencing comparative LCA results.

     

Life cycle assessment of two baby food packaging alternatives: glass jars vs. plastic pots

Background, aim, and scope  This paper compares the life cycle assessment (LCA) of two packaging alternatives used for baby food produced by Nestlé: plastic pot and glass jar. The study considers the environmental impacts associated with packaging systems used to provide one baby food meal in France, Spain, and Germany in 2007. In addition, alternate logistical scenarios are considered which are independent of the two packaging options. The 200-g packaging size is selected as the basis for this study. Two other packaging sizes are assessed in the sensitivity analysis. Because results are intended to be disclosed to the public, this study underwent a critical review by an external panel of LCA experts. Materials and methods  The LCA is performed in accordance to the international standards ISO 14040 and ISO 14044. The packaging systems include the packaging production, the product assembly, the preservation process, the distribution, and the packaging end-of-life. The production of the content (before preservation process), as well as the use phase are not taken into account as they are considered not to change when changing packaging. The inventory is based on data obtained from the baby food producer and the suppliers, data from the scientific literature, and data from the ecoinvent database. Special care is taken to implement a system expansion approach for end-of-life open and closed loop recycling and energy production (ISO 14044). A comprehensive impact assessment is performed using two life cycle impact assessment methodologies: IMPACT 2002+ and CML 2001. An extensive uncertainty analysis using Monte Carlo as well as an extensive sensitivity study are performed on the inventory and the reference flows, respectively. Results  When looking at the impacts due to preservation process and packaging (considering identical distribution distances), we observe a small but significant environmental benefit of the plastic pot system over the glass jar system. Depending on the country, the impact is reduced by 14% to 27% for primary energy, 28% to 31% for global warming, 31% to 34% for respiratory inorganics, and 28% to 31% for terrestrial acidification/nutrification. The environmental benefit associated with the change in packaging mainly results from (a) production of plastic pot (including its end-of-life; 43% to 51% of total benefit), (b) lighter weight of packaging positively impacting transportation (20% to 35% of total benefit), and (c) new preservation process permitted by the plastic system (23% to 34% of total benefit). The jar or pot (including cap or lid, cluster, stretch film, and label) represents approximately half of the life cycle impacts, the logistics approximately one fourth, and the rest (especially on-site energy, tray, and hood) one fourth. Discussion  The sensitivity analysis shows that assumptions made in the basic scenarios are rather conservative for plastic pots and that the conclusions for the 200-g packaging size also apply to other packaging sizes. The uncertainty analysis performed on the inventory for the German market situation shows that the plastic pot system has less impact than the glass jar system while considering similar distribution distances with a confidence level above 97% for most impact categories. There is opportunity for further improvement independent of the type of packaging used, such as by reducing distribution distances while still optimizing lot size. The validity of the main conclusions presented in this study is confirmed by results of both impact assessment methodologies IMPACT 2002+ and CML 2001. Conclusions  For identical transportation distances, the plastic pot system shows a small but significant reduction in environmental burden compared to the glass jar system. Recommendations and perspectives  As food distribution plays an important role in the overall life cycle burdens and may vary between scenarios, it is important to avoid additional transportation of the packaged food in order to maintain or even improve the advantage of the plastic pot system. The present study focuses on the comparison of packaging systems and directly related consequences. It is recommended that further environmental optimization of the product also includes food manufacturing (before preservation process) and the supply chain of raw materials.