| 1. |
- Björklund, Anna, et al.
(author)
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Recycling revisited - life cycle comparisons of global warming impact and total energy use of waste management strategies
- 2005
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In: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 44:4, s. 309-317
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Journal article (peer-reviewed)abstract
- Recycling of waste materials has been analysed from a life cycle perspective in a number of studies over the past 10-15 years. Publications comparing the global warming impact and total energy use of recycling versus incineration and landfilling were reviewed in order to find out to what extent they agree or contradict each other, and whether there are generally applicable conclusions to be drawn when certain key factors are considered. Four key factors with a significant influence on the ranking between recycling, incineration, and landfilling were identified. Producing materials from recycled resources is often, but not always, less energy intensive and causes less global warming impact than from virgin resources. For non-renewable materials the savings are of such a magnitude, that apparently the only really crucial factor is what material is replaced. For paper products, however, the savings of recycling are much smaller. The ranking between recycling and incineration of paper is sensitive to for instance paper quality, energy source avoided by incineration, and energy source at the mill.
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| 2. |
- Blomberg, Jerry, et al.
(author)
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The economics of secondary aluminium supply: An econometric analysis based on European data
- 2009
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In: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 58:8, s. 455-463
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Journal article (peer-reviewed)abstract
- The purpose of this paper is to analyze the economics of secondary aluminium supply in Western Europe. We derive a supply model of secondary aluminium recovery and recycling, which integrates microeconomic theory of production with a dynamic model of scrap generation and accumulation. The supply function contains the secondary output price, a vector of input prices, and a measure of the size of the stock of old aluminium scrap. The model is estimated using pooled cross-section and annual time-series data for four European countries, Germany, France, Italy and the United Kingdom, over the time period 1983-2000. The estimated own-price elasticity of secondary aluminium supply is low (0.21) as is the supply response to changes in the stock of old scrap. The empirical results are useful for analyzing market behavior and policy impacts in the secondary aluminium market. The low supply responses to changes in the output price can - in combination with the high-income elasticity of material demand - help explain the observed price volatility of secondary aluminium prices. They also suggest that price-based policies influencing the supply side of the market may only have limited impacts on aluminium recycling rates, and that national collection of aluminium scrap is likely to have small influences on secondary aluminium production internationally.
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| 3. |
- Brandén Klang, Anders, 1967-, et al.
(author)
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Sustainable management of combustible household waste-Expanding the integrated evaluation model
- 2008
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In: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 52:8-9, s. 1101-1111
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Journal article (peer-reviewed)abstract
- A previously described model for the evaluation of sustainability in waste management has been expanded and applied to biodegradable and other combustible household waste. The model was applied to a case-study focusing on the special conditions in a municipality in the sparsely populated region of northern Sweden. In this region it is usual that the collection distances are long, the volume of waste is low and treatment facilities are remote. Four scenarios for the management of municipal household waste were compared: incineration, anaerobic digestion, composting and landfilling. A system analysis was performed to ensure that each scenario fulfil all the functions that the waste could provide (heat, electricity, fuel, and soil with a high nutrient content) and a sensitivity analysis was carried out to test the reliability of the results. The results show that the evaluation model can be used to assess the sustainability aspects of different treatment scenarios for combustible household waste. The model also allows for an individual interpretation of the results presented, depending on the choice of priorities. The effects of varying the time horizons and the difference in impact depending on what fuels are ultimately replaced in energy production are discussed.
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| 4. |
- Davis, Jenny, et al.
(author)
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Time-dependent material flow analysis of iron and steel in the UK. : Part 2. Scrap generation and recycling
- 2007
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In: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 51:1, s. 118-140
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Journal article (peer-reviewed)abstract
- This paper presents an analysis of the use of iron and steel in the UK and explores how much of the iron and steel is recycled when it becomes obsolete after use. The first part of this paper series investigated production and consumption trends of iron and steel in the UK, whereas this paper focuses on scrap generation and recycling. Information on the amounts of iron and steel going into different groups of goods, together with values for their estimated lifetimes, have enabled modelling of the annual release of iron and steel from the use phase in the form of end-of-life scrap. This is an application to material flow accounting of the theory of residence time distributions used routinely in chemical reaction engineering. By comparing modelled generation of scrap with actual scrap consumption in the UK, we obtain estimates of loss or accumulation of iron and steel scrap in the UK. The model indicates that as much as 30% of the scrap that was potentially available in 2001 as end-of-life scrap has either been accumulated within the economic system or lost to landfill. © 2006 Elsevier B.V. All rights reserved.
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| 5. |
- Dodoo, Ambrose, et al.
(author)
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Carbon implications of end-of-life management of building materials
- 2009
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In: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 53:5, s. 276-286
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Journal article (peer-reviewed)abstract
- In this study we investigate the effects of post-use material management on the life cycle carbon balance of buildings, and compare the carbon balance of a concrete-frame building to that of a wood-frame building. The demolished concrete is either landfilled, or is crushed into aggregate followed by exposure to air for periods ranging from 4 months to 30 years to increase carbonation uptake of CO2. The demolished wood is assumed to be used for energy to replace fossil fuels. We calculate the carbon flows associated with fossil fuel used for material production, calcination emission from cement manufacture, carbonation of concrete during and after its service life, substitution of fossil fuels by recovered wood residues, recycling of steel, and fossil fuel used for post-use material management. We find that carbonation of crushed concrete results in significant uptake of CO2. However, the CO2 emission from fossil fuel used to crush the concrete significantly reduces the carbon benefits obtained from the increased carbonation due to crushing. Stockpiling crushed concrete for a longer time will increase the carbonation uptake, but may not be practical due to space constraints. Overall, the effect of carbonation of post-use concrete is small. The post-use energy recovery of wood and the recycling of reinforcing steel both give higher carbon benefit than the post-use carbonation. We conclude that carbonation of concrete in the post-use phase does not affect the validity of earlier studies reporting that wood-frame buildings have substantially lower carbon emission than concrete-frame buildings.
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| 6. |
- Dornburg, Veronika
(author)
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Optimising waste treatment systems - Part A: Methodology and technological data for optimising energy production and economic performance
- 2006
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In: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 49:1, s. 68-88
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Journal article (peer-reviewed)abstract
- The treatment and utilisation of biomass residues and waste for energy and recycling can contribute significantly to greenhouse gas emission reduction. Therefore, a waste treatment structure should be designed for an efficient saving of fossil primary energy in terms of maximal primary energy savings or minimal costs per unit of primary energy savings. However, this is a complex task, given the large number of technologies, recycling options and their logistic consequences, that necessitate an integrated analysis. Also, on longer term various new and improved technologies become available which can affect performances for options from an economic and/or energy point of view. For that reason, an optimisation tool, that optimises a biomass and waste treatment system for a given amount of biomass and waste, is developed in this study. This optimal biomass and waste treatment system is composed of several treatment installations, that are characterised by scale, location and kind of technology. Important aspects that are taken into account in the analysis are heat distribution, biomass and waste transport and economies of scale. A broad variety of technologies for material recycling, conversion of biomass and/or waste to heat, electricity or transportation fuel are included in the optimisation tool. Performance data of these technologies are based on an extensive review. Examples of included technologies comprise: integrated gasification with combined cycle, waste incineration, pyrolysis, digestion, co-firing in fossil power plants, biomass incineration, hydro-thermal upgrading, paper recycling and chipboard production. A comparison of the different technologies in relation to scale shows that primary energy savings and costs per unit of primary energy savings diverge significantly. In general, the optimisation tool developed here is suitable for analyses of optimal biomass and waste treatment structures in different regions with regard to primary energy savings and their costs. By means of scenario analysis, robust optimal solutions in terms of primary energy savings and their costs can be identified and the influence of important parameters can be analysed. A case study of the Dutch biomass and waste treatment systems has been carried out with the optimisation tool and is presented in part two of this article.
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| 7. |
- Dornburg, Veronika, et al.
(author)
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Optimising waste treatment systems - Part B: Analyses and scenarios for The Netherlands
- 2006
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In: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 48:3, s. 227-248
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Journal article (peer-reviewed)abstract
- Material recycling as well as energetic production of biomass residues and other solid wastes could significantly contribute to fossil primary energy savings. Waste treatment should, therefore, aim to combine pollution abatement with the efficient saving of fossil primary energy. This article identifies optimal waste treatment strategies in The Netherlands. Here, an optimal strategy is one that either maximises the fossil primary energy savings or minimises the costs per unit of fossil primary energy savings that are achieved by the utilisation of available biomass residues and wastes. Also, the influence of different factors - for example, the availability of wastes or technological developments - on the robustness of technological options and on the variation of costs and fossil primary energy savings is studied. With a specially developed optimisation tool (described in Part I of this article series) several variants of Dutch waste treatment systems ('scenarios') are analysed by back casting to the year 2020. This tool allows for quick analyses of complete waste treatment infrastructures. The results show that the objective of the Dutch government to supply 120PJ of primary energy demand in 2020 from biomass and waste seems more than feasible, while in 2000 about 43 PJ were realised. Including material recycling up to 437 PJ primary energy could be saved with an optimised waste treatment infrastructure. Choices made about alternative waste treatment strategies influence the costs strongly. Total costs for the Dutch waste treatment system - not considering revenues from waste treatment tariffs - vary from revenues of 230EUEO million/year to costs of 820EURO million/year. The contributions of material and energy recycling to avoid primary energy use change significantly under different preconditions. In the 11 different scenarios considered, of the primary energy savings achieved 25-76% resulted from material recycling, 20-80% from heat and electricity production, and a more modest 0-21% from the production of transport fuel. (Biomass) integrated gasification with combined cycle, hydro-thermal upgrading and waste separation emerge as key technologies from this study, while for example, waste incineration and biomass co-firing in coal power plants do not come out as most attractive options for the longer term. Generally, large-scale conversion units seem favourable to achieve better economies and energy recovery.
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| 8. |
- Durinck, D., et al.
(author)
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Hot stage processing of metallurgical slags
- 2008
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In: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 52:10, s. 1121-1131
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Journal article (peer-reviewed)abstract
- Slags are an indispensable tool for the pyrometallurgical industry to extract and purify metals at competitive prices. Large volumes are produced annually, leading to important economical and ecological issues regarding their afterlife. To maximise the recycling potential, slag processing has become an integral part of the valorisation chain. However, processing is often directed solely towards the cooled slag. In this article, the authors present an overview of the scientific studies dedicated to the hot stage of slag processing, i.e. from the moment of slag/metal separation to complete cooling at the slag yard. Using in-depth case studies on C2S driven slag disintegration and chromium leaching, it is shown that the functional properties of the cooled slag can be significantly enhanced by small or large scale additions to the high temperature slag and/or variations in the cooling path, even without interfering with the metallurgical process. The technology to implement such hot stage processing steps in an industrial environment is currently available. No innovative technological solutions are required. Rather, advances in hot stage slag processing seem to rely primarily on further unravelling the relationships between process, structure and properties. This knowledge is required to identify the critical process parameters for quality control. Moreover, it could even allow to consciously alter slag compositions and cooling paths to tailor the slag to a certain application.
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| 9. |
- Geyer, R., et al.
(author)
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Time-dependent material fl{ligature}ow analysis of iron and steel in the UK. : Part 1: Production and consumption trends 1970-2000
- 2007
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In: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 51:1, s. 101-117
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Journal article (peer-reviewed)abstract
- This paper presents a detailed account of the supply chain for iron and steel in the UK, using material fl{ligature}ow analysis. Due to the lack of a universally agreed methodology of material fl{ligature}ow analysis, we include an explanation of the accounting methodology employed in the study. Data for the supply chain has been collected reaching back three decades, enabling analysis of trends in production and consumption of iron and steel over the years. This fi{ligature}rst part of a series of two papers quantifi{ligature}es the iron and steel fl{ligature}ows through the UK economy including the annual amount of iron and steel embodied in all fi{ligature}nal goods that enter the use phase in the UK. The second part explores the more elusive fl{ligature}ows of scrap generation and recycling. In this fi{ligature}rst paper we show that the UK no longer has the capacity to recycle the scrap it collects and is increasingly relying on foreign economies to do so. We also observe that trade in iron and steel products and ferrous metal containing fi{ligature}nal goods has increased dramatically over the years, but remained relatively balanced. Today, one-half of UK's iron and steel production is exported, whereas one-half of the iron and steel entering the UK use phase comes from imported fi{ligature}nal goods. The efficiency with which the UK iron and steel industry transforms iron ore and scrap into iron and steel products has increased substantially. However, there is no significant downward trend in the absolute level of iron and steel use in the UK. Between 1970 and 1981 the annual amount of steel put to use dropped from 16.4 to 10.7 million metric tonnes but climbed back up to 15 million metric tonnes twice since then. © 2006 Elsevier B.V. All rights reserved.
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| 10. |
- Hage, Olle, et al.
(author)
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Norms and economic motivation in household recycling: Empirical evidence from Sweden
- 2009
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In: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 53:3, s. 155-165
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Journal article (peer-reviewed)abstract
- This paper analyzes the determinants of recycling efforts in Swedish households, and focuses on the case of packaging waste (i.e., paper, glass, plastic, and metal). The analysis builds on a theoretical framework that integrates norm-motivated behavior into a simple economic model of household choice by assuming that the individuals have preferences for maintaining a self-image as morally responsible, and thus norm-compliant, persons. A postal survey was sent out randomly to 2800 households in four different Swedish municipalities, and in the paper self-reported information on recycling rates at the household level is analyzed in an ordered probit regression framework. The results indicate that both economic and moral motives influence inter-household recycling rates. Specifically, convenience matters in the sense that property-close collection in multi-family dwelling houses leads to higher collection rates. The strength of moral (self-enforced) norms explains a large part of the variation across households, but the importance of such norms in driving recycling efforts partly diminishes if improved collection infrastructure makes it easier for households to recycle. Recycling rates at the household level are also positively influenced by the felt ability to favourably affect environmental outcomes as well as by others' recycling efforts. The paper discusses a number of policy implications that follow from the empirical results.
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