| 1. |
- 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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| 2. |
- Egeskog, Andrea, 1981, et al.
(författare)
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Co-generation of biofuels for transportation and heat for district heating systems – an assessment of the national possibilities in the EU
- 2009
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Ingår i: Energy Policy. - Amsterdam : Elsevier BV. - 0301-4215 .- 1873-6777. ; 37:12, s. 5260-5272
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Tidskriftsartikel (refereegranskat)abstract
- Biomass gasification with subsequent synthesis to liquid or gaseous biofuels generates heat possible to use in district heating (DH) systems. The purpose here is to estimate the heat sink capacity of DH systems in the individual EU nations and assess the possibilities for biomass-gasification-based co-generation of synthetic biofuels for transportation and heat (CBH) for DH systems in the EU countries. The possibilities are assessed (i) assuming different levels of competiveness relative to other heat supply options of CBH corresponding to the EU target for renewable energy for transportation for 2020 and (ii) assuming that the potential expansion of the DH systems by 2020 is met with CBH. In general, the size of the DH heat sinks represented by the existing national aggregated DH systems can accommodate CBH at a scale that is significant compared to the 2020 renewable transportation target. The possibilities for CBH also depend on its cost-competitiveness compared to, e.g., fossil-fuel-based CHP. The possible expansion of the DH systems by 2020 represents an important opportunity for CBH and is also influenced by the potential increase in the use of other heat supply options, such as, industrial waste heat, waste incineration, and CHP.
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| 3. |
- Habibi, Shiva, 1978, et al.
(författare)
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Comparison of free-floating car-sharing services in cities
- 2017
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Ingår i: ECEEE Summer Study, 29 May - 3 June, 2017. - 2001-7960. - 9789198387810 ; 2017
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Konferensbidrag (refereegranskat)abstract
- In recent years, free-floating car sharing services (FFCS) have been offered by many organizations as a more flexible option compared to traditional car sharing. FFCS allows users to pick up and return cars anywhere within a specified area of a city. FFCS can provide a high degree of utilization of vehicles and less usage of infrastructure in the form of parking lots and roads and thus has the potential to increase the efficiency of the transport sector. However, there is also a concern that these compete with other efficient modes of transport such as cycling and public transport. The aim of this paper is to better understand how, when and where the vehicles are utilized through logged data of the vehicles’ movements. We have access to data collected on FFCS services in 22 cities in Europe and North America which allows us to compare the usage pattern in different cities and examine whether or not there are similar trends. In this paper, we use the collected data to compare the different cities based on utilization rate, length of trip and time of day that the trip is made. We find that the vehicle utilization rates differ between cities with Madrid and Hamburg having some of the highest utilization levels for the FFCS vehicles. The results form a first step of a better understanding on how these services are being used and can provide valuable input to local policy makers as well as future studies such as simulation models.
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| 4. |
- Magnusson, Thomas, 1970-, et al.
(författare)
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Circular economy, varieties of capitalism and technology diffusion : Anaerobic digestion in Sweden and Paraná
- 2022
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Ingår i: Journal of Cleaner Production. - Amsterdam, Netherlands : Elsevier. - 0959-6526 .- 1879-1786. ; 335
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Tidskriftsartikel (refereegranskat)abstract
- The transition to a circular economy relies on systems that facilitate waste recovery and recirculation of resources. These systems are based on certain enabling technologies. The aim of this paper is to explain how socio-economic structures influence the diffusion of such technologies. It applies a framework built on societal embedding and varieties of capitalism to compare the diffusion of anaerobic digestion (AD) in Sweden in northern Europe and Paraná in southern Brazil. Both Sweden and Paraná have experienced accelerated diffusion of AD, but there are significant differences in the respective diffusion patterns. The comparative analysis points to a tradeoff between system complexity and speed of diffusion. It illustrates how AD can be presented as a solution to various problems, and it further shows how the specific problems that gain attention shape diffusion patterns. By showing how socio-economic structures influence the appointment of problem owners, their agency, and legitimate forms of institutional support, the analysis demonstrates how economic systems condition technology diffusion.
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| 5. |
- Persson, Urban, 1961-, et al.
(författare)
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Current and future prospects for heat recovery from waste in European district heating systems : a literature and data review
- 2016
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Ingår i: Energy. - London : Elsevier. - 0360-5442 .- 1873-6785. ; 110, s. 116-128
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Tidskriftsartikel (refereegranskat)abstract
- Municipal solid waste has seen increasing annual volumes for many decades in contemporary Europe and constitutes, if not properly managed, an environmental problem due to local pollution and greenhouse gas emissions. From an energy perspective, waste is also an alternative fuel for power and heat generation; energy recovery from waste represents an effective measure to reduce landfilling and avoid disposal emissions while simultaneously reducing the equivalent demand for primary energy supply. A key factor for obtaining the full synergetic benefits of this energy recovery is the presence of local heat distribution infrastructures, without which no large-scale recovery and utilisation of excess heat is possible. In this paper, which aims to estimate municipal solid waste volumes available for heat recovery in European district heating systems in 2030, a literature and data review is performed to establish and assess current and future EU (European Union) waste generation and management. Main conclusions are that more heat can be recovered from current Waste-to-Energy facilities operating at low average heat recovery efficiencies, that efficient incineration capacity is geographically concentrated, and that waste available for heat recovery in 2030 is equally determined by total generation volumes by this year as by future EU deployment levels of district heating. © 2015 Elsevier Ltd.
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| 6. |
- Averfalk, Helge, 1988-, et al.
(författare)
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Low‐temperature excess heat recovery in district heating systems : The potential of European Union metro stations
- 2020
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Ingår i: Book of Abstracts. ; , s. 34-34
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents an assessment of the excess heat recovery potential from EU metro stations. The assessment is a sub-study on low temperature recovery opportunities, explored in the H2020 ReUseHeat project, and consists of spatial mapping of 1994 underground stations with quantitative estimates of sensible and latent heat, monthly and annually, attainable in rejected platform ventilation exhaust air. Being a low-temperature source, the assessment conceptually anticipates recovery of attainable heat with compressor heat pumps to facilitate the temperature increase necessary for utilisation in district heating systems. Further, the paper explores the influence on useful excess heat volumes from low-temperature heat recoveries when distributed at different temperature levels. The findings, which distinguishes available (resource) and accessible (useful) excess heat potentials, indicate an annual total EU28 available potential of ~21 PJ, characterised by a certain degree of seasonal temporality, and corresponding accessible potentials of ~40 PJ per year at 3rd generation distribution, and of ~31 PJ at anticipated 4th generation conditions. Despite lower accessible volumes, utilisation in 4th generation systems are naturally more energy efficient, since relatively less electricity is used in the recovery process, but also more cost-effective, since heat pumps, at lower temperatures, can be operated at capacities closer to design conditions and with less annual deviations.
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| 7. |
- Dénarié, Alice, et al.
(författare)
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A validated method to assess the network length and the heat distribution costs of potential district heating systems in Italy
- 2021
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Ingår i: International Journal of Sustainable Energy Planning and Management. - Aalborg, Denmark : Aalborg Universitetsforlag. - 2246-2929. ; 31, s. 59-78
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Tidskriftsartikel (refereegranskat)abstract
- The evaluation of the district heating network investment costs requires the knowledge of its topology. However, when assessing district heating potential, the topology is not known a priori and a simulation is required. One method for modelling future heat networks involves the use of Minimum Spanning Tree, from the graph theory. In this work, the MST is used together with real networks lengths to elaborate an updated equation describing the effective width in correlation with the number of building ratio instead of plot ratio. The reason motivating the use of simulated networks lies in the goal of analysing sparse areas where there’s a general lack of data. In this study, the census cells vertexes and local roads layout are used as inputs for the application of the MST in order to simulate DH network layouts in areas where DH is not present. The method has been validated by running simulations in areas where DH is already present, allowing the comparison of the respective lengths. The validation shows a variable but systematic overestimation of the simulated lengths. The study of the error has brought to the definition of a correlation between accuracy of results and the share of buildings with centralized heating systems suitable for DH connection. The updated version of the effective width confirms the exponential tendency and gives higher results for Italian cities then for Scandinavian ones, showing an important impact of the city structure in the curve. The city of Milano is finally used as a case study to show the effects of using the updated effective width curve.
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| 8. |
- Dénarié, Alice, et al.
(författare)
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Assessment of renewable and waste heat recovery for DH through GIS mapping : the national potential in Italy
- 2020
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Ingår i: Book of Abstracts. ; , s. 129-129
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This work aims at showing the potential of waste and renewable heat recovery in Italy through detailed mapping of these sources. The ambition of this analysis is to highlight the areas with important heat recovery potential and to show how the matching with suitable heat demand would allow its exploitation through district heating expansion. The importance of waste heat and renewable heat potentially recoverable to reduce primary energy consumption in the civil sector is widely recognized. Nevertheless, these potential is widely unexploited in Italy. The processes and energy sources have been analysed in terms of geographical location, quantification of available heat and recovery costs with a special focus on temperature levels. The main distinction between low temperature and high temperature heat sources has been applied in order to identify the heat recovery characteristics and the consequent additional costs for temperature upgrades. The inputs of the analysis performed in this work come from national database, which has allowed obtaining more detailed and wider results with respect to international existing studies on the same subject. Two different approaches have been used to map potential heat: one to identify and quantify existing waste heat recovery and one to assess and estimate energy coming from potential new plants. The analysed sources belonging to the first category are industrial processes, waste to energy plants, waste water treatment plants and datacentres, while biomass, geothermal energy and electrolysis plants estimation belong to the second one. Results shows that the national available waste and renewable heat amount to 270 TWh which is an important outcome in comparison with a national heat demand for the residential and tertiary sector of 400 TWh. Out of this results, according to a nuts 3 regional aggregation of heat demand, 95 TWh could be recovered in DH. The reduction from theoretical potential of 270 TWh to 95 TWh is due to geographical matching of heat demand and available waste heat and on some hypothesis related to the diffusion of DH. This work shows the huge unexpressed potential of waste heat reutilisation in Italy and how the mapping of recoverable heat and not only its quantification is essential to properly estimate the utilization potential.
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| 9. |
- Dénarié, Alice, et al.
(författare)
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Assessment of waste and renewable heat recovery in DH through GIS mapping : The national potential in Italy
- 2021
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Ingår i: Smart Energy. - Amsterdam : Elsevier. - 2666-9552. ; 1
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Tidskriftsartikel (refereegranskat)abstract
- This work aims at showing the unexploited potential of waste and renewable heat in Italy through detailed mapping of these sources. The ambition is to highlight the areas with an important heat recovery potential that could be exploited through DH expansion. The recoverable heat sources have been analysed in terms of geographical location, and recovery aspects with a special focus on temperature levels and technological implications for temperature upgrades. The methodology presented in this work addresses not only the theoretical potential of waste heat and renewable heat use in DH, but also several technical aspects to get a result as closer as possible to the realistic potential at national level. Two different approaches have been used to map potential heat: one to quantify existing waste heat recovery from industrial processes, waste to energy plants, wastewater treatment plants and one to estimate the energy coming from potential new plants based on biomass, geothermal energy and solar thermal. Results shows that for a total heat demand for the civil sector of 329 TWh, out of which 114 TWh come out being suitable for a DH connection, the national available waste and renewable heat that could be integrated in DH amounts to 156 TWh. These results show the significant unexpressed potential of waste heat use in Italy and how its mapping is essential to properly estimate the utilization potential. This work has been commissioned by AIRU, Italian DH association. Copyright © 2021 Elsevier Ltd.
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| 10. |
- Lichtenwöhrer, Peter, et al.
(författare)
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Report on decarbonisation design-approaches based on urban typologies : Deliverable D2.5
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report identifies different typology-based approaches and methods for decarbonising the energy sector of cities. Respectively, typologies were evaluated, and design approaches were developed. In a first step, already existing typologies were evaluated, including a study by the Technical University of Darmstadt and examples from the City of Vienna. In a next step, conceivable structuring criteria and decarbonisation approaches from existing work within the DCP project were identified and summarised. These include structuring criteria such as heat demand density, renewable energy sources or types of refurbishment activities. On this basis, a new typology was developed. Five highly weighted criteria could be derived from the results of the expert survey, including structural energy efficiency, coverage of district heating, potential for renewable sources, potential for waste heat and heat demand density. These criteria formed the basis for the development of the novel typology. The first typology represents areas with high compatibility with highly weighted criteria, the third typology represents areas with comparably low compatibility, while the second typology is associated in between. Based on the developed typology, six design approaches were presented in this report. One short-term and one long-term approach for each typology include recommendations as well as concrete measures for strategic decision-making.
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