| 1. |
- Liu, Qianyun, et al.
(författare)
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Roadside assessment of a modern city bus fleet: Gaseous and particle emissions
- 2019
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Ingår i: Atmospheric Environment: X. - : Elsevier BV. - 2590-1621. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- © 2019 The Authors In many cities worldwide, modern fleets have been introduced to reduce gaseous and particle emissions from city buses. To date, most emission studies are limited to a few vehicles, making a statistically significant assessment of control options difficult, especially under real-world driving conditions. Exhaust emissions of 234 individual city buses were measured under real-world stop-and-go traffic conditions at a bus stop in Gothenburg, Sweden. The buses comprised models fulfilling Euro III-VI and EEV (Enhanced Environmentally Friendly Vehicle) standards with different engine technologies, fuels, and exhaust after-treatment systems, and also included hybrid-electric buses (HEV). Both gaseous (NOx, CO, HC, and SO2) and size-resolved particle number (PN) and mass (PM) emission factors (EF) were calculated for vehicles using compressed natural gas (CNG), diesel (DSL), Rapeseed Methyl Ester (RME) and Hydro-treated Vegetable Oil (HVO) equipped with various after-treatment technologies, e.g., diesel particulate filter (DPF), selective catalytic reduction (SCR) and exhaust gas recirculation (EGR) systems. The highest median EFPN was obtained from Euro VHEV-HVO-SCR buses (MdEFPN = 18×1014 # kg-1) when their combustion engines were used though 53% of their accelerations were below detection limits indicating the use of their electrical engine. The highest MdEFPM was obtained from the Euro V-DSL-SCR buses (MdEFPM = 150 mg kg-1) and the lowest from EEV-CNG buses (below detection threshold) and Euro VIHEV-HVO- SCR+EGR+DPF buses (MdEFPM = 19 mg kg-1). The highest MdEFNOx was obtained from the Euro V-RME-SCR (MdEFNOx = 30 g kg-1) and Euro VHEV-HVO-SCR buses (MdEFNOx = 24 g kg-1), and the lowest from CNG buses (MdEFNOx = 4.8 g kg-1) and Euro VIHEV-HVO-SCR+EGR+DPF buses (MdEFNOx = 7.4 g kg-1). Hybrid buses can give higher PN emissions compared to traditional diesel engines, likely due to downsized combustion engines. Replacing diesel by biodiesel fuel reduced MdEFPM significantly but increased MdEFNOx which may be due to the higher combustion temperature and oxygen contents of the fuel (for RME). Overall, the EEV-CNG buses performed the best regarding both the MdEF and low contribution to the high emitters. It was also found that a small (5%) proportion of the buses contributed significantly (14-30%) to the total emissions. Identification and monitoring the maintenance of the high emitters in the fleets should be considered for the improvement of air quality.
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| 2. |
- Earon, Robert, et al.
(författare)
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Groundwater Resources Potential in Hard Rock Terrain : A Multivariate Approach
- 2014
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Ingår i: Ground Water. - : John Wiley & Sons. - 0017-467X .- 1745-6584.
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Tidskriftsartikel (refereegranskat)abstract
- Groundwater resources are limited and difficult to predict in crystalline bedrock due to heterogeneity and anisotropy in rock fracture systems. Municipal-level governments often lack the resources for traditional hydrogeological tests when planning for sustainable use of water resources. A new methodology for assessing groundwater resources potential (GRP) based on geological and topographical factors using principal component analysis (PCA) and analysis of variance (ANOVA) was developed and tested. ANOVA results demonstrated statistically significant differences in classed variable groups as well as in classed GRP scores with regard to hydrogeological indicators, such as specific capacity (SC) and transmissivity. Results of PCA were used to govern the weight of the variables used in the prediction maps. GRP scores were able to identify 79% of wells in a verification dataset, which had SC values less than the total dataset median. GRP values showed statistically significant correlations using both parametric (using transformed datasets) and non-parametric methods. The method shows promise for municipal or regional level planning in crystalline terrains with high levels of heterogeneity and anisotropy as a hydrogeologically and statistically based tool to assist in assessing groundwater resources. The methodology is executed in a geographic information systems environment, and uses often readily available data, such as geological maps, feature maps and topography, and thus does not require expensive and time-consuming aquifer tests.
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| 3. |
- André, Hampus, 1989
(författare)
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Resource and Environmental Impacts of Resource-Efficiency Measures Applied to Electronic Products
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Natural resources such as ecosystems, land, water and metals underpin the functioning of economies and human well-being, and are becoming increasingly scarce due to growth in population and affluence. Metals are increasingly demanded for their specific properties as modern technology develops. The dependence on metals is of growing concern due to the environmental impacts related, for example, to energy use and local impacts from mining, as well as the scarcity risks posed by socio-economic, geological and geopolitical constraints. Thus, there is a clear need to use metals and other natural resources more efficiently. The vision of a circular economy has been proposed as a way to do this, for example by improving durability, reusing, repairing and recycling. Such so-called resource-efficiency (RE) measures are commonly assumed to be environmentally beneficial, although the evidence is not plentiful. It is plausible that focusing on recirculating products and materials could shift burdens to other environmental impacts or life cycle stages. It has therefore been argued that a life cycle-based approach, such as in life cycle assessment (LCA), is useful to critically assess the environmental implications of RE measures. LCA aims to quantify the environmental impacts of products over their entire life cycles - from cradle to grave - assessing a wide range of impacts such as toxicity, climate change and metal resource use. For metal resource use, however, there are a number of perspectives as to what constitutes the actual environmental problem. These perspectives are represented in a variety of life cycle impact assessment methods (LCIA) which have previously been shown to give diverging results. Electronic products are emblematic of metal resource use challenges since they deploy a broad spectrum of scarce metals. This thesis aims to provide knowledge on the potential for RE measures to reduce the environmental impacts of electronic products, by addressing the following research questions: (1) What resource-efficiency measures result in reduced potential environmental impacts and resource use – for what types of products and under what conditions? (2) How does extended use of electronic products through design for increased technical lifetime, reuse and repair affect environmental impacts, particularly metal resource use? (3) How does the application of different LCIA methods for metal resource use influence interpretations of resource-efficiency measures applied to electronic products? This thesis builds on three appended papers which are all based on comparative assessments of resource efficiency, studied as resource use and environmental impacts per function delivered, using LCA and material flow analysis. The results indicate that extended use of electronic products through increasing technical lifetimes, reusing and repairing, is generally resource-efficient. Exceptions may occur, however, if extended use is insufficient to motivate impacts from producing more durable products or spare parts. Use extension of electronic products leads to resource efficiency in two distinct ways: through the intended use extension and by increasingly steering material flows into recycling. Further resource efficiency could be realised by combining RE measures over the entire life cycles of products. With regards to metal resource use, the choice of LCIA method can influence the interpretation of the results of RE measures for electronic products. Therefore, it is advisable to use several complementary LCIA methods to minimise the risks of overlooking potentially important resources issues. Furthermore, better understanding and transparency of such issues is valuable in order to provide more comprehensive information to decision-makers.
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| 4. |
- Lindahl, Niklas, 1981, et al.
(författare)
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Early stage techno-economic and environmental analysis of aluminium batteries
- 2023
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Ingår i: Energy Advances. - : Royal Society of Chemistry (RSC). - 2753-1457. ; 2:3, s. 420-429
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Tidskriftsartikel (refereegranskat)abstract
- For any proper evaluation of next generation energy storage systems technological, economic, and environmental performance metrics should be considered. Here conceptual cells and systems are designed for different aluminium battery (AlB) concepts, including both active and passive materials. Despite the fact that all AlBs use high-capacity metal anodes and materials with low cost and environmental impact, their energy densities differ vastly and only a few concepts become competitive taking all aspects into account. Notably, AlBs with high-performance inorganic cathodes have the potential to exhibit superior technological and environmental performance, should they be more reversible and energy efficient, while at the system level costs become comparable or slightly higher than for both AlBs with organic cathodes and lithium-ion batteries (LIBs). Overall, with continued development, AlBs should be able to complement LIBs, especially in light of their significantly lower demand for scarce materials. Several aluminium battery concepts are evaluated at material, cell and system levels for technical, economic and environmental performance, which enables them to complement lithium-ion batteries in the future.
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| 5. |
- Englund, Oskar, 1982, et al.
(författare)
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Large-scale deployment of grass in crop rotations as a multifunctional climate mitigation strategy
- 2023
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Ingår i: GCB Bioenergy. - : Wiley. - 1757-1707 .- 1757-1693. ; 15:2, s. 166-184
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Tidskriftsartikel (refereegranskat)abstract
- The agriculture sector can contribute to climate change mitigation by reducing its own greenhouse gas (GHG) emissions, sequestering carbon in vegetation and soils, and providing biomass to substitute for fossil fuels and other GHG-intensive products. The sector also needs to address water, soil, and biodiversity impacts caused by historic and current practices. Emerging EU policies create incentives for cultivation of perennial plants that provide biomass along with environmental benefits. One such option, common in northern Europe, is to include grass in rotations with annual crops to provide biomass while remediating soil organic carbon (SOC) losses and other environmental impacts. Here, we apply a spatially explicit model on >81,000 sub-watersheds in EU27 + UK (Europe) to explore the effects of widespread deployment of such systems. Based on current accumulated SOC losses in individual sub-watersheds, the model identifies and quantifies suitable areas for increased grass cultivation and corresponding biomass- and protein supply, SOC sequestration, and reductions in nitrogen emissions to water as well as wind and water erosion. The model also provides information about possible flood mitigation. The results indicate a substantial climate mitigation potential, with combined annual GHG savings from soil-carbon sequestration and displacement of natural gas with biogas from grass-based biorefineries, equivalent to 13%–48% of current GHG emissions from agriculture in Europe. The environmental co-benefits are also notable, in some cases exceeding the estimated mitigation needs. Yield increases for annual crops in modified rotations mitigate the displacement effect of increasing grass cultivation. If the grass is used as feedstock in lieu of annual crops, the displacement effect can even be negative, that is, a reduced need for annual crop production elsewhere. Incentivizing widespread deployment will require supportive policy measures as well as new uses of grass biomass, for example, as feedstock for green biorefineries producing protein concentrate, biofuels, and other bio-based products.
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| 6. |
- Maia De Souza, Danielle, et al.
(författare)
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Ecosystem services in life cycle assessment: A synthesis of knowledge and recommendations for biofuels
- 2018
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Ingår i: Ecosystem Services. - : Elsevier BV. - 2212-0416. ; 30, s. 200-210
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Forskningsöversikt (refereegranskat)abstract
- There is an increasing trend in promoting the use of biofuels for transportation as a low-fossil carbon energy source, but little knowledge on their multidimensional environmental impacts. Whole-system approaches, such as life cycle assessment (LCA), have been extensively employed to analyze the environmental performance of different biofuels. However, it remains unclear to which extent biofuels impact ecosystems and the services they provide, in particular related to different management practices. To overcome this challenge, this paper draws recommendations to better holistically address ecosystem services (ES) in LCA, with a focus on biofuels. We first pinpoint some of the challenges in accounting for the concept of ES in decision-making and review some of the existing ES classification frameworks and the usefulness of the cascade model. Second, we discuss the implications of identified context-specific aspects on the modeling of biofuel production impacts on ES in LCA. Finally, we propose a conceptual framework to link ES classification systems, the cascade model and the LCA approach. Although some challenges still remain unsolved, due to the existing life cycle impact assessment structure, existing ES frameworks and the cascade model are helpful tools to better include ES into LCA of different biofuels.
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| 7. |
- Diamond, Miriam, et al.
(författare)
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Exploring the planetary boundary for chemical pollution
- 2015
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 78, s. 8-15
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Forskningsöversikt (refereegranskat)abstract
- Rockström et al. (2009a, 2009b) have warned that humanity must reduce anthropogenic impacts defined by nine planetary boundaries if “unacceptable global change” is to be avoided. Chemical pollution was identified as one of those boundaries for which continued impacts could erode the resilience of ecosystems and humanity. The central concept of the planetary boundary (or boundaries) for chemical pollution (PBCP or PBCPs) is that the Earth has a finite assimilative capacity for chemical pollution, which includes persistent, as well as readily degradable chemicals released at local to regional scales, which in aggregate threaten ecosystem and human viability. The PBCP allows humanity to explicitly address the increasingly global aspects of chemical pollution throughout a chemical's life cycle and the need for a global response of internationally coordinated control measures. We submit that sufficient evidence shows stresses on ecosystem and human health at local to global scales, suggesting that conditions are transgressing the safe operating space delimited by a PBCP. As such, current local to global pollution control measures are insufficient. However, while the PBCP is an important conceptual step forward, at this point single or multiple PBCPs are challenging to operationalize due to the extremely large number of commercial chemicals or mixtures of chemicals that cause myriad adverse effects to innumerable species and ecosystems, and the complex linkages between emissions, environmental concentrations, exposures and adverse effects. As well, the normative nature of a PBCP presents challenges of negotiating pollution limits amongst societal groups with differing viewpoints. Thus, a combination of approaches is recommended as follows: develop indicators of chemical pollution, for both control and response variables, that will aid in quantifying a PBCP(s) and gauging progress towards reducing chemical pollution; develop new technologies and technical and social approaches to mitigate global chemical pollution that emphasize a preventative approach; coordinate pollution control and sustainability efforts; and facilitate implementation of multiple (and potentially decentralized) control efforts involving scientists, civil society, government, non-governmental organizations and international bodies.
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| 8. |
- Muangmeesri, Suthawan, 1997-, et al.
(författare)
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Recycling of Polyesters by Organocatalyzed Methanolysis Depolymerization : Environmental Sustainability Evaluated by Life Cycle Assessment
- 2024
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 12:10, s. 4114-4120
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Tidskriftsartikel (refereegranskat)abstract
- Polyethylene terephthalate (PET) is one of the most common plastics and can be cascaded mechanically during its life cycle. However, recycling affects the mechanical properties of the material, and the virgin material is constantly in demand. If a worn material could be depolymerized to its chemical building blocks, then a virgin polymer could be generated from old fibers. In this work, we have developed a benign organo-catalytic depolymerization of PET to yield dimethyl terephthalate (DMT) and ethylene glycol (EG) without the need for purification of generated monomers. By recirculating the solvent and organo-catalyst, a solvent/substrate ratio of 3:1 was achieved. The depolymerization was successfully applied to other polyesters, polycarbonates, and polycotton. The cotton isolated from the polycotton depolymerization was successfully processed into viscose fibers with a tenacity in the range of nonwaste cotton-derived viscose filaments. The global warming potential (GWP) of PET depolymerization was evaluated by using life cycle assessment (LCA). The GWP of 1 kg PET recycling is 2.206 kg CO2 equivalent, but the process produces DMT, EG, and heat, thereby avoiding the emissions equivalent to 4.075 kg CO2 equivalent from the DMT, EG, and steam-energy production through conventional pathways. Thus, the net result potentially avoids the emission of 1.88 kg of CO2 equivalent. The impact of this process is lower than that of waste PET incineration and conventional PET recycling technologies.
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| 9. |
- Thomas, Jean-Baptiste, et al.
(författare)
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A comparative environmental life cycle assessment of hatchery, cultivation, and preservation of the kelp Saccharina latissima
- 2021
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Ingår i: Ices Journal of Marine Science. - : Oxford University Press (OUP). - 1054-3139 .- 1095-9289. ; 78:1, s. 451-467
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Tidskriftsartikel (refereegranskat)abstract
- Seaweed cultivation and processing industries could contribute to sustainable blue growth and the European bioeconomy. This article contributes a case study evaluation of environmental sustainability of preserved brown seaweed Saccharina latissima by means of environmental life cycle assessment of a pilot facility in Sweden. The study accounts for nutrient bioremediation and carbon capture and includes two alternative hatchery processes, a 2-ha longline cultivation, and four alternative preservation methods (hang-drying outdoors, heated air-cabinet drying, ensiling, and freezing). The study found that as a result of carbon capture and nitrogen and phosphorus uptake (bioremediation) by seaweed, more CO2 and PO4 equivalents are (temporarily) absorbed than emitted by the supply chain. The extent of emissions is most affected by preservation methods undertaken. Impact profiles of the supply chain show that the greatest impact shares result from freezing and air-cabinet drying, both the two most energy-intensive processes, followed by the cultivation infrastructure, highlighting strategic optimization opportunities. Hatchery processes, harvesting, and the low-energy ensilage and hang-drying outdoors were found to have relatively small impact shares. These findings presage the environmentally friendliness of seaweed-based products by documenting their potential to mitigate eutrophication and climate change, even when taking a life cycle perspective.
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| 10. |
- Vikström, Hanna, 1985-, et al.
(författare)
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Lithium availability and future production outlooks
- 2013
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 110:10, s. 252-266
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Tidskriftsartikel (refereegranskat)abstract
- Lithium is a highly interesting metal, in part due to the increasing interest in lithium-ion batteries. Several recent studies have used different methods to estimate whether the lithium production can meet an increasing demand, especially from the transport sector, where lithium-ion batteries are the most likely technology for electric cars. The reserve and resource estimates of lithium vary greatly between different studies and the question whether the annual production rates of lithium can meet a growing demand is seldom adequately explained. This study presents a review and compilation of recent estimates of quantities of lithium available for exploitation and discusses the uncertainty and differences between these estimates. Also, mathematical curve fitting models are used to estimate possible future annual production rates. This estimation of possible production rates are compared to a potential increased demand of lithium if the International Energy Agency’s Blue Map Scenarios are fulfilled regarding electrification of the car fleet. We find that the availability of lithium could in fact be a problem for fulfilling this scenario if lithium-ion batteries are to be used. This indicates that other battery technologies might have to be implemented for enabling an electrification of road transports.
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