| 1. |
- Agrawal, Munmun, et al.
(författare)
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Global market trends of tantalum and recycling methods from Waste Tantalum Capacitors: A review
- 2021
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Ingår i: Sustainable Materials and Technologies. - : Elsevier BV. - 2214-9937. ; 29
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Forskningsöversikt (refereegranskat)abstract
- The rapid digitalization of the world, technological up-gradation, and shorten life cycle of electronic gadgets leading to the generation of an enormous amount of waste tantalum capacitors (WTCs) rich in tantalum every year. The need of the hour is to develop an effective way to recycle tantalum from these waste scraps considering the scarcity of tantalum, environmental impacts, resource and energy utilization, and lower recycling rates. In this paper, various existing methods of recovery of metallic tantalum from WTCs have been extensively reviewed. Processes have been examined in light of recovery efficiency, purity of the resultant product, process complexity, and limitations. The bottleneck in the recovery of tantalum from WTCs is the presence of tightly covered mold resin over the surface of the tantalum anode. Various researchers have recovered Ta with varying degrees of success. Pyrolysis, followed by chloride metallurgy, has been proven to be an effective technology on account of its high removal rate, resource and energy utilization, and lesser environmental impacts. This article also explores the global scenario of tantalum. Overall this review provides a foundation to understand the potential barrier and various opportunities associated with the recovery of tantalum from WTCs.
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| 2. |
- Ahlgren, Serina, et al.
(författare)
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Review of methodological choices in LCA of biorefinery systems - key issues and recommendations
- 2015
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Ingår i: Biofuels, Bioproducts and Biorefining. - : Wiley. - 1932-1031 .- 1932-104X. ; 9:5, s. 606-619
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Forskningsöversikt (refereegranskat)abstract
- The current trend in biomass conversion technologies is toward more efficient utilization of biomass feedstock in multiproduct biorefineries. Many life-cycle assessment (LCA) studies of biorefinery systems have been performed but differ in how they use the LCA methodology. Based on a review of existing LCA standards and guidelines, this paper provides recommendations on how to handle key methodological issues when performing LCA studies of biorefinery systems. Six key issues were identified: (i) goal definition, (ii) functional unit, (iii) allocation of biorefinery outputs, (iv) allocation of biomass feedstock, (v) land use, and (vi) biogenic carbon and timing of emissions. Many of the standards and guidelines reviewed here provide only general methodological recommendations. Some make more specific methodological recommendations, but these often differ between standards. In this paper we present some clarifications (e.g. examples of research questions and suitable functional units) and methodological recommendations (e.g. on allocation).
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| 3. |
- Calvin, Katherine, et al.
(författare)
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Bioenergy for climate change mitigation: Scale and sustainability
- 2021
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Ingår i: GCB Bioenergy. - : Wiley. - 1757-1707 .- 1757-1693. ; 13:9, s. 1346-1371
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Forskningsöversikt (refereegranskat)abstract
- Many global climate change mitigation pathways presented in IPCC assessment reports rely heavily on the deployment of bioenergy, often used in conjunction with carbon capture and storage. We review the literature on bioenergy use for climate change mitigation, including studies that use top-down integrated assessment models or bottom-up modelling, and studies that do not rely on modelling. We summarize the state of knowledge concerning potential co-benefits and adverse side effects of bioenergy systems and discuss limitations of modelling studies used to analyse consequences of bioenergy expansion. The implications of bioenergy supply on mitigation and other sustainability criteria are context dependent and influenced by feedstock, management regime, climatic region, scale of deployment and how bioenergy alters energy systems and land use. Depending on previous land use, widespread deployment of monoculture plantations may contribute to mitigation but can cause negative impacts across a range of other sustainability criteria. Strategic integration of new biomass supply systems into existing agriculture and forest landscapes may result in less mitigation but can contribute positively to other sustainability objectives. There is considerable variation in evaluations of how sustainability challenges evolve as the scale of bioenergy deployment increases, due to limitations of existing models, and uncertainty over the future context with respect to the many variables that influence alternative uses of biomass and land. Integrative policies, coordinated institutions and improved governance mechanisms to enhance co-benefits and minimize adverse side effects can reduce the risks of large-scale deployment of bioenergy. Further, conservation and efficiency measures for energy, land and biomass can support greater flexibility in achieving climate change mitigation and adaptation.
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| 4. |
- Gebremeskel, Dawit, et al.
(författare)
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Long-term electricity supply modelling in the context of developing countries: The OSeMOSYS-LEAP soft-linking approach for Ethiopia
- 2023
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Ingår i: Energy Strategy Reviews. - : Elsevier BV. - 2211-467X. ; 45
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Forskningsöversikt (refereegranskat)abstract
- Long-term power supply modelling is particularly important for developing countries in providing sustainable solutions to electricity problems. This study presents the first detailed and complete model of the Ethiopian electricity system while considering the unique features (dominance of traditional energy, informal economy, urban-rural divide, low electrification, supply shortage, etc.) and context of developing countries that is developed by soft-linking the OSeMOSYS (Open-Source energy Modelling System) and LEAP (Long-range Energy Alternatives Planning System) modelling frameworks. Better system representation and design of plausible scenarios that explore the potential pathways of the future power supply and demand evolution until 2050 is done by performing sensitivity analysis. Sector wise and technological representation of supply and end-uses at a disaggregated level, assessment of centralized grid-based means and decentralized off-grid methods for improving electricity access are the main methodological contributions. Five policy scenarios are employed to explore different possible futures and balance the long-term electricity needs and resources. The improved efficiency scenario reduces the installed capacity by 9 GW which translates into approximately 11% total discounted cost saving (USD $ 4 billion). This economic benefit has made the efficiency scenario the most desirable compared to the other scenarios. Attributed to lower investment costs and abundant resource availability, the results show that renewable technologies are more competitive and favourable.
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| 5. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Environmental Assessment of Emerging Technologies: Recommendations for Prospective LCA
- 2018
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Ingår i: Journal of Industrial Ecology. - : Wiley. - 1530-9290 .- 1088-1980. ; 22:6, s. 1286-1294
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Forskningsöversikt (refereegranskat)abstract
- The challenge of assessing emerging technologies with life cycle assessment (LCA) has been increasingly discussed in the LCA field. In this article, we propose a definition of prospective LCA: An LCA is prospective when the (emerging) technology studied is in an early phase of development (e.g., small-scale production), but the technology is modeled at a future, more-developed phase (e.g., large-scale production). Methodological choices in prospective LCA must be adapted to reflect this goal of assessing environmental impacts of emerging technologies, which deviates from the typical goals of conventional LCA studies. The aim of the article is to provide a number of recommendations for how to conduct such prospective assessments in a relevant manner. The recommendations are based on a detailed review of selected prospective LCA case studies, mainly from the areas of nanomaterials, biomaterials, and energy technologies. We find that it is important to include technology alternatives that are relevant for the future in prospective LCA studies. Predictive scenarios and scenario ranges are two general approaches to prospective inventory modeling of both foreground and background systems. Many different data sources are available for prospective modeling of the foreground system: scientific articles; patents; expert interviews; unpublished experimental data; and process modeling. However, we caution against temporal mismatches between foreground and background systems, and recommend that foreground and background system impacts be reported separately in order to increase the usefulness of the results in other prospective studies.
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| 6. |
- Billen, Gilles, et al.
(författare)
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Reshaping the European agro-food system and closing its nitrogen cycle: The potential of combining dietary change, agroecology, and circularity
- 2021
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Ingår i: One Earth. - : Elsevier BV. - 2590-3322 .- 2590-3330. ; 4:6, s. 839-850
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Forskningsöversikt (refereegranskat)abstract
- After World War II, the evolution of Europe's agro-food system has been marked by intensified use of synthetic fertilizers, territorial specialization, and integration in global food and feed markets. This evolution led to increased nitrogen (N) losses to aquatic environments and the atmosphere, which, despite increasing environmental regulations, continues to harm ecosystems and human well-being. Here, we explore how these N losses can be drastically reduced in a scenario synergistically operating three levers: (1) a dietary change toward less animal products and an efficient recycling of human excreta; (2) the generalization of region-specific organic crop rotation systems involving N2-fixing legumes, making it possible to do without synthetic N fertilizers; and (3) the reconnection of livestock with cropping systems allowing optimal use of manure. This scenario demonstrates the possibility to feed the projected European population in 2050 without imports of feed and with half the current level of environmental N losses.
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| 7. |
- Cardoso Chrispim, Mariana, Postdoktor, 1990-, et al.
(författare)
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Phosphorus recovery from municipal wastewater treatment : Critical review of challenges and opportunities for developing countries
- 2019
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Ingår i: Journal of Environmental Management. - Amsterdam : Elsevier. - 0301-4797 .- 1095-8630. ; 248
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Forskningsöversikt (refereegranskat)abstract
- The aim of this paper is to provide guidance in selecting phosphorus recovery options within the municipal wastewater treatment sector regarding developing countries. This critical review includes a brief contextualization of the resource-oriented sanitation paradigm, the discussion of processes for phosphorus recovery based on methods at full-scale, pilot-scale and laboratory-scale, and a concise discussion of the environmental impacts and benefits associated with phosphorus recovery strategies. Finally, the main challenges related to the implementation of resource recovery strategies, especially for phosphorous, were identified and discussed. According to the results, some of the main drivers for phosphorus recovery are the limited availability of phosphorus, increasing cost of phosphate fertilizers and reduction of maintenance costs. Currently, most of the operational processes are based on crystallization or precipitation from the digester supernatant. Struvite is the most common recovered product. The recovery rate of phosphorus from the liquid phase is lower (10–60% from wastewater treatment plant influent), than from sludge (35–70%) and from sludge ashes (70–98%). Phosphorus recovery remains challenging, and some barriers identified were the integration between stakeholders and institutions, public policies and regulations as well as public acceptance and economic feasibility. In developing countries, the implementation of nutrient recovery systems is challenging, because the main concern is on the expansion of sanitation coverage. Resource recovery approaches can provide benefits beyond the wastewater treatment sector, not only improving the sustainability of wastewater treatment operations, but generating revenue for the utility provider.
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| 8. |
- Ding, Yunji, et al.
(författare)
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Recovery of precious metals from electronic waste and spent catalysts: A review
- 2019
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Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 141, s. 284-298
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Forskningsöversikt (refereegranskat)abstract
- Precious metals are widely applied in many industry fields due to their excellent corrosion resistance, good electrical conductivity and high catalytic activity. However, the reserves of precious metals falls short of the production globally. The rapid generation of end-of-life products has become the significant resources of precious metals. Among these products, electronic waste (e-waste) and spent catalysts are more concentrated since they account for over 90% of precious metals in industry. This article provides an overview of various technologies on the recovery of precious metals from e-waste and spent catalysts. It shows that recycling technologies have been significantly improved in recent years. The recycling processes have transferred from leaching by aqua regia, cyanide and chlorine in acid solution to less pollution agents leaching. Environment-oriented technologies have been raised great attention in precious metals recycling. The advantages and environmental impacts of these recycling technologies have been discussed in detail. However, there are still some challenges for future promotion. In order to achieve the environment-friendly and sustainable recycling for precious metals with high recovery rate, several considerations have been proposed.
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| 9. |
- Lee, Christina, 1992, et al.
(författare)
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The environmental impact of extraction: A holistic review of the quarry lifecycle
- 2024
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Ingår i: Cleaner Environmental Systems. - 2666-7894. ; 13
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Forskningsöversikt (refereegranskat)abstract
- As more companies start disclosing environmental, social, & governance (ESG) information, a holistic understanding of environmental impact is needed to provide transparency on the different concerns of stakeholders from different backgrounds. The extraction industries are poised to play a pivotal role in providing key environmental information to downstream organizations. However, these industries face unique environmental challenges, making it difficult to identify what is significant to disclose. This article explores significant environmental impacts within the quarrying sector, from a lifecycle perspective. Quarries, where mechanical extraction and processing for rock products (including aggregates and ornamental stone) occur, are integral for infrastructure projects worldwide. To identify significant environmental aspects that should be considered in comprehensive environmental assessment for quarry stakeholders, a systematic literature review is conducted with in-depth content analysis. This reveals potential significant environmental impacts, trends, and crucial knowledge gaps. Nine relevant environmental aspects are found across six lifecycle stages for quarries. Notably, differences in environmental concepts are observed. To help overcome some conceptual barriers and improve understanding at a holistic level, environmental aspects are mapped to endpoint impacts where notable damages can occur. The findings suggest more harmonization of significance assessment for environmental impacts is needed to facilitate cross-disciplinary discourse. Waste management and transport emerge as key areas that demand increased attention. Additionally, future research efforts should focus on exploring ways to reduce environmental impact in quarries.
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| 10. |
- Liu, Jun, et al.
(författare)
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Resource utilization of municipal solid waste incineration fly ash - cement and alkali-activated cementitious materials: A review
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 852
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Forskningsöversikt (refereegranskat)abstract
- The increase in municipal solid waste (MSW) production has led to an increase in MSW incineration fly ash (MSWIFA) production. MSWIFA contains toxic and harmful substances such as heavy metals and dioxins, which can cause harm to the environment if not treated properly. Only a few MSWIFAs will be landfilled directly, and the rest will need to be treated by other methods. The treatment of MSWIFA can be divided into three types: separation, stabilization/solidification (S/S), and thermal treatment, which are either not fully developed or too costly. Resource utilization is a sustainable means of treating MSWIFA. MSWIFA is used in the production of cement and alkali-activated cementitious materials as a means of resource utilization with significant advantages. This can alleviate the consumption of nature and reduce greenhouse gas emissions in conventional cement production. Compared with MSWIFA cement, MSWIFA alkali-activated cementitious material can be achieved with almost no consumption of natural resources, which is worthy of further research to realize the large-scale application of MSWIFA. At the end of the paper, the perspective of separation of dioxins from MSWIFA, co-processing of MSWI ash, and production of “MSWIFA green materials” is presented.
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