The incorporation of waste prevention activities into life cycle assessments of municipal solid waste management systems: methodological issues

Background, aim, and scope  

Municipal solid waste (MSW) management organizations commonly address both waste treatment and diversion activities in their management plans, yet the application of life cycle assessment (LCA) to MSW rarely incorporates the effects of waste prevention activities (WPAs) in an explicit manner. The primary objective of this paper is to further develop the methodological options for attributional LCAs of MSW to address waste prevention, including product reuse.     

Life cycle assessment of ceramic tiles. Environmental and statistical analysis

Purpose  

The aim of this paper is to conduct a life cycle assessment study of ceramic tiles (single-fired glazed stoneware) in order to identify the stages that produce the greatest impact on the environment and the materials and/or processes that make the largest contribution to that impact. The life cycle is considered to be made up of seven stages: (1) mining the clay, (2) atomising the clay, (3) production of frits and glazes, (4) production of ceramic tiles, (5) distribution, (6) installation and usage, and, on ending their useful life (7) treatment as construction and demolition waste.     

End-of-life and waste management in life cycle assessment—Zurich, 6 December 2011

Introduction  

Waste management is a key component in society's strategy to mitigate the adverse effects of its economic activities. Through its comprehensive system approach, life cycle assessment (LCA) is frequently put forward as a powerful tool for the assessment of waste management activities. However, many methodological challenges regarding the environmental assessment of waste treatment systems still remain, and consensus is still far from being reached in areas like the definition of (temporal) system boundaries, life cycle inventory generation, selection and use of environmental indicators, and interpretation and communication of the LCA results.     

EASEWASTE—life cycle modeling capabilities for waste management technologies

Background, aim, and scope  

The management of municipal solid waste and the associated environmental impacts are subject of growing attention in industrialized countries. European Union has recently strongly emphasized the role of LCA in its waste and resource strategies. The development of sustainable solid waste management systems applying a life cycle perspective requires readily understandable tools for modeling the life cycle impacts of waste management systems. The aim of the paper is to demonstrate the structure, functionalities, and LCA modeling capabilities of the PC-based life cycle-oriented waste management model EASEWASTE, developed at the Technical University of Denmark specifically to meet the needs of the waste system developer with the objective to evaluate the environmental performance of the various elements of existing or proposed solid waste management systems.     

Reliability-based life cycle assessment for future solid waste management alternatives in Portugal

Background, aim, and scope  

This paper presents a study related to the application of the reliability-based life cycle assessment (LCA) to assess different alternatives for solid waste management in the Setúbal peninsula, Portugal. The current system includes waste collection, transport, sorting, recycling, and mechanical and biological treatment (MBT) by means of aerobic treatment and landfill. In addition, some future expansion plans are discussed.     

Life cycle assessment of the average Spanish diet including human excretion

Background, aim and scope  

The aim of this work is to find out to what extent human excretion is relevant in the context of a Spaniard’s overall food intake. A case study dealing with the average Spanish diet is carried out, including the whole life cycle of food: agricultural and animal production, industrial processing, distribution and retail, home storage and cooking, solid waste management and human excretion.     

Life cycle emissions and energy study of biodiesel derived from waste cooking oil and diesel in Singapore

Background, aim and scope  

Biodiesel derived from Waste Cooking Oil (WCO) is considered highly environmentally sustainable since WCO is a waste product from domestic and commercial cooking processes and then recycled to a transportation fuel in Singapore. In addition, it avoids the conversion of land use for crop production. This is a strong advantage for Singapore which has relatively smaller land space than other countries. The import of virgin oil as feedstock into Singapore is also avoided. Therefore, the more appropriate feedstock to produce biodiesel in Singapore context is WCO. According to the National Environment Agency, diesel vehicles in Singapore contribute 50% of the total particulate matter smaller than 2.5 μm (PM_0.25) emissions to air ambient. Hence, the aim of this life cycle assessment study was to compare the environmental performances of biodiesel derived from WCO and low sulphur diesel in terms of global warming potential, life cycle energy efficiency (LCEE) and fossil energy ratio (FER) using the life cycle inventory. The results of this study would serve as a reference for energy policy makers and environmental agencies.     

The formulation of life cycle impact assessment framework for Malaysia using Eco-indicator

Background, aim, and scope  

Life Cycle Assessment (LCA) is an emerging supporting tool designed to help practitioner in systematically assessing the environmental performance of selected product’s life cycle. A product’s life cycle includes the extraction of raw materials, production, and usage, and ends with waste treatment or disposal. Life cycle impact assessment (LCIA) as a part of LCA is a method used to derive the environmental burdens from selected product’s stages. LCIA is structured in classification, characterization, normalization and weighting. Presently most of the LCIA practices use European database to establish the characterization, normalization and weighting value. However, using these values for local LCA practice might not be able to reflect the actual Malaysian’s environmental scenario. The aim of this study is to create a Malaysian version of normalization and weighting value using the pollution database within Malaysia.     

Life cycle impact assessment and interpretation of municipal solid waste management scenarios based on the midpoint and endpoint approaches

Purpose  

Few studies have examined differing interpretations of life cycle impact assessment (LCIA) results between midpoints and endpoints for the same systems. This paper focuses on the LCIA of municipal solid waste (MSW) systems by taking both the midpoint and endpoint approaches and uses LIME (Life Cycle Impact Assessment Method based on Endpoint Modeling, version 2006). With respect to global and site-dependent factors, environmental impact categories were divided into global, regional, and local scales. Results are shown as net emissions consisting of system emissions and avoided emissions.     

Design of recycling system for poly(methyl methacrylate) (PMMA). Part 1: recycling scenario analysis

Introduction

In this series of papers, we present a poly(methyl methacrylate) (PMMA) recycling system design based on environmental impacts, chemical hazards, and resource availability. We evaluated the recycling system by life cycle assessment, environment, health, and safety method, and material flow analysis.

Purpose

Previous recycling systems have not focused on highly functional plastics such as PMMA, partly because of lower available volumes of waste PMMA compared with other commodity plastics such as polyethylene or polypropylene. However, with the popularization of PMMA-containing products such as liquid crystal displays, the use of PMMA is increasing and this will result in an increase in waste PMMA in the future. The design and testing of recycling systems and technologies for treating waste PMMA is therefore a high research priority. In this study, we analyze recycling of PMMA monomers under a range of scenarios.

Methods

Based on the differences between PMMA grades and their life cycles, we developed a life cycle model and designed a range of scenarios for PMMA recycling. We obtained monomer recycling process inventory data based on the operational results of a pilot plant. Using this process inventory data, we quantified life cycle greenhouse gas (LC-GHG) emissions and fossil resource consumption, and we calculated the LIME single index.

Results and discussion

PMMA produces more than twice the amount of GHG emissions than other commodity resins. Through scenario and sensitivity analyses, we demonstrated that monomer recycling is more effective than mechanical recycling. Operational modifications in the monomer recycling process can potentially decrease LC-GHG emissions.

Conclusions

Highly functional plastics should be recycled while maintaining their key functions, such as the high transparency of PMMA. Monomer recycling has the potential to achieve a closed-loop recycling of PMMA.     

A life cycle assessment of residential waste management and prevention

Purpose

The oft-cited waste hierarchy is considered an important rule of thumb to identify preferential waste management options and places waste prevention at the top. Nevertheless, it has been claimed that waste prevention can sometimes be less favorable than recycling because (1) recycling decreases only the primary production of materials, whereas waste prevention may reduce a combination of both primary and low-impact secondary production, and (2) waste prevention decreases the quantity of material recycled downstream and the avoided impacts associated with recycling. In response to this claim, this study evaluates the life cycle effects of waste prevention activities (WPAs) on a residential waste management system.

Methods

This life cycle assessment (LCA) contrasts the net impacts of a large residential solid waste management system (including sanitary landfilling, anaerobic digestion, composting, and recycling) with a system that incorporates five WPAs, implemented at plausible levels (preventing a total of 3.6 % of waste generation tonnage) without diminishing product service consumption. WPAs addressed in this LCA reduce the collected tonnage of addressed advertising mail, disposable plastic shopping bags, newspapers, wine and spirit packaging, and yard waste (grass).

Results and discussion

In all cases, the WPAs reduce the net midpoint and endpoint level impacts of the residential waste management system. If WPAs are incorporated, the lower impacts from waste collection, transportation, sorting, and disposal as well as from the avoided upstream production of goods, more than compensate for the diminished net benefits associated with recycling and the displaced electricity from landfill gas utilization.

Conclusions

The results substantiate the uppermost placement of waste prevention within the waste hierarchy. Moreover, further environmental benefits from waste prevention can be realized by targeting WPAs at goods that will be landfilled and at those with low recycled content.     

End of life of buildings: three alternatives, two scenarios. A case study

Purpose

The objective of this case study is to identify the relevant processes needed in the environmental assessment of the end of life of a building and to identify the demolition process variables that significantly affect energy consumption and emissions of greenhouse gases. Different scenarios of demolition, based on three alternatives for managing construction and demolition waste (C&DW) generated during demolition works, are analyzed. This study is based upon typical construction and demolition practices and waste management in Spain.

Methods

Life cycle assessment (LCA) methodology is applied to assess objectively and quantitatively different C&DW management plans during the design phase and to identify the significant environmental aspects. The impact categories considered are global warming potential and human toxicity potential. Furthermore, the indicator primary energy (non renewable energy from fossil fuels) is also studied.

Results

Design of C&DW management plans to enhance the recovery of waste, reducing significantly the selected environmental indicators, was assessed in this study. Waste transport from the demolition work to the treatment plant and the transport of the non-recyclable fraction to the final disposal, as well as the fuel consumption in hydraulic demolition equipment and in the loading/unloading equipment of the treatment plants, are the most significant environmental aspects associated with the management plan based on a selective demolition, whereas in a conventional demolition process, the main environmental aspect is waste transport from the demolition work to final disposal.

Conclusions

LCA studies allow an assessment of different demolition processes. A tool for recording environmental data has been developed. This tool provides in a systematic manner life cycle inventory and life cycle impact assessment of the end of life of a building, facilitating the study of management plans in the design phase.     

Application of LCSA to used cooking oil waste management

Purpose

Used cooking oil (UCO) is a domestic waste generated as the result of cooking and frying food with vegetable oil. The purpose of this study is to compare the sustainability of three domestic UCO collection systems: through schools (SCH), door-to-door (DTD), and through urban collection centres (UCC), to determine which systems should be promoted for the collection of UCO in cities in Mediterranean countries.

Methods

The present paper uses the recent life cycle sustainability assessment (LCSA) methodology. LCSA is the combination of life cycle assessment (LCA), life cycle costing, and social life cycle assessment (S-LCA).

Results and discussion

Of the three UCO collection systems compared, the results show that UCC presents the best values for sustainability assessment, followed by DTD and finally SCH system, although there are no substantial differences between DTD and SCH. UCC has the best environmental and economic performance but not for social component. DTD and SCH present suitable values for social performance but not for the environmental and economic components.

Conclusions

The environmental component improves when the collection points are near to citizens’ homes. Depending on the vehicle used in the collection process, the management costs and efficiency can improve. UCO collection systems that carry out different kind of waste (such as UCC) are more sustainable than those that collect only one type of waste. Regarding the methodology used in this paper, the sustainability assessment proposed is suitable for use in decision making to analyse processes, products or services, even so in social assessment an approach is needed to quantify the indicators. Defining units for sustainability quantification is a difficult task because not all social indicators are quantifiable and comparable; some need to be adapted, raising the subjectivity of the analysis. Research into S-LCA and LCSA is recent; more research is needed in order to improve the methodology.     

Life cycle inventory for electric energy system in Brazil

Goal, Scope and Background  

The goal of this paper is to present the modeling of life cycle inventory (LCI) for electric energy production and delivery in Brazil for the reference year 2000 by application of ISO 14040. Site specific data along with sector production data have been combined to construct an energy production model, which has been applied to emissions estimation. Background-data of all the inputs and outputs from the system have been inventoried as follows: gross electric energy generation, installed nameplate capacity, flooded area, losses, emissions to air / water, process waste, used fuel, efficiency and land use.     

Service life prediction of residential interior finishes for life cycle assessment

Purpose  

Service life of building products has an important influence on life cycle assessment (LCA) results of buildings. The goal of this study was to propose a systematic approach to estimate service life of building products by including both technical and social factors.     

Inventory analysis of the timber industry in Ghana

Background, aim, and scope  

The timber sector, i.e., forestry and timber industry, plays an important role in the socioeconomic development of Ghana through timber products export. Timber production in this sector is associated with increasing environmental burdens in terms of use of materials and energy, production of emissions and waste, and land use changes. The purpose of this study was to compile a comprehensive life cycle inventory (LCI) to identify the most dominant environmental pressures for five major production lines in the timber industry, and to evaluate the influence of the choice of the functional unit on the results (1 m³, 1 kg, and 1 euro). LCA’s of wood typically base their functional unit on volume, but mass or money may be more appropriate for the rather different products considered in this study.     

A system dynamics approach in LCA to account for temporal effects—a consequential energy LCI of car body-in-whites

Purpose  

The purpose of this paper is to take steps towards a life cycle assessment that is able to account for changes over time in resource flows and environmental impacts. The majority of life cycle inventory (LCI) studies assume that computation parameters are constants or fixed functions of time. This assumption limits the opportunities to account for temporal effects because it precludes consideration of the dynamics of the product system.     

Life cycle carbon footprint of the National Geographic magazine

Purpose  

Climate change is an urgent and serious global problem. Life cycle assessment methods may be used to evaluate the life cycle carbon footprint of a product, such as the National Geographic magazine. The results of the study provide the publisher and material suppliers with information to reduce life cycle greenhouse gas (GHG) emissions. The study also informs consumers of the GHG emissions associated with the product. The purpose of this study was to document the life cycle carbon footprint of the National Geographic magazine.     

Practitioners' use of life cycle costing with environmental costs—a Swedish study

Purpose  

The aim of this paper is to describe life cycle costing (LCC) practices in some Swedish organisations, investigate probable changes and determine whether and how environmental costs (internal and/or external) are considered in current LCC.     

Parameterised inventories for life cycle assessment

Background and Objective  

Life cycle assessment (LCA) is a highly data intensive undertaking, where collecting the life cycle inventory (LCI) data is the most labour intensive part. The aim of this paper is to show a method for representing the LCI in a simplified manner which not only allows an estimative, quantitative LCA, but also the application of advanced analysis methods to LCA.