| 1. |
- Bergman, Filip, 1992-, et al.
(författare)
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A Critical Review of the Sustainability of Multi-Utility Tunnels for Colocation of Subsurface Infrastructure
- 2022
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Ingår i: Frontiers in Sustainable Cities. - : Frontiers Media S.A.. - 2624-9634. ; 4
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Forskningsöversikt (refereegranskat)abstract
- Multi-utility tunnel (MUT) have received increasing attention as an alternative method for installing subsurface infrastructure for the distribution of electricity, telecommunications, water, sewage and district heating. MUTs are described as a potentially more sustainable technology than conventional open-cut excavation (OCE), especially if the entire life cycle of these cable and pipe networks is taken into account. Based on an extensive review of the academic literature, this article aims to identify and critically examine claims made about the pros and cons of using MUT for the placement of subsurface infrastructure. Identified claims are mapped, and their validity and applicability assessed. These claims are then analyzed from a sustainability perspective, based on the three sustainability dimensions and a life cycle perspective. The results show that a variety of advantages and disadvantages of using MUTs for subsurface infrastructure are highlighted by the articles, but several of these are without any empirical support. When some form of empirical support is presented, it usually comes from case-specific analyses of MUTs, and the applicability in other MUT projects is seldom discussed. Economic performance is the sustainability dimension that has received the most attention, while environmental performance has not been analyzed in the reviewed literature, which is a major limitation of the current knowledge. In summary, the knowledge about the sustainability performance of using MUTs for subsurface infrastructure is still limited and incoherent. In order to increase the knowledge, this article points out the importance of new case studies, in which the sustainability consequences of using MUTs for subsurface infrastructure are mapped and evaluated by combining both quantitative and qualitative assessment methods.
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| 2. |
- Bergman, Filip, 1992-
(författare)
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Sustainability performance of multi-utility tunnels : Sustainability assessments for furthering knowledge and understanding
- 2022
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The multi-utility tunnel has received increased attention as an alternative method for the installation of subsurface infrastructure for the distribution of electricity, water, sewage and district heating. In previous research, the multi-utility tunnel (MUT) has been described as a more sustainable technology compared to the conventionally used technique where the cables and pipes are placed with open-cut excavation (OCE), especially when the entire life cycle is taken into account. This thesis aims to contribute to an improved understanding of MUT's sustainability performance in relation to conventional installation using open-cut excavation. This is done by using literature study, interview study and quantitative sustainability assessments to gain an understanding of the current state of knowledge. Furthermore, this thesis also focuses on how knowledge can be deepened with the help of quantitative sustainability assessments and the challenges of conducting this type of assessment. This thesis shows that the state of knowledge regarding MUT's sustainability performance is low and scattered, with a lack of a holistic approach. Direct economic performance has gained the most attention, followed by indirect and social impact, and the environmental impact has so far barely been assessed. The sustainability performance depends to a large extent on the conditions of the specific case, and these should be considered when assessing the technology. Quantitative assessments have the potential to help deepen the knowledge of the sustainability implications of using MUT. The characteristics of MUT have some similarities with other types of physical infrastructure. Similarities are that the systems are long-lived, have project conditions that affect sustainability performance, and impact a broad spectrum of actors. One difference to typical infrastructure systems is that the owner and management structure of MUT is, by design, more complex as several types of utility systems are in use. The characteristics of MUT give some practical considerations that need to be addressed: data availability, including practitioners; detailed data; transparency; and flexibility. This thesis highlights the complexity of assessing MUT´s sustainability performance and advocates that future studies should have a learning-oriented approach so that the knowledge level can collectively and gradually improve over time rather than focusing on decision-oriented studies.
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| 3. |
- Cordova, Stephanie S., 1988-
(författare)
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Utilizing CO2 from biomethane production : Sustainability and climate performance
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Biogas solutions offer many benefits for the environment and society, including organic waste treatment as well as being an enabler for energy and nutrient recovery. The products of anaerobic digestion are a biogas, which contains a share of 30 to 50% carbon dioxide (CO2) and 50 to 70% methane, and a liquid remanent, rich in nutrients. The biogas can be upgraded by removing the CO2 to increase the energy content, producing biomethane. At present, CO2 is considered a waste in biomethane production systems, and hence it is emitted into the atmosphere. Nevertheless, biogas upgrading technologies separate a pure-grade CO2 and, likewise, carbon capture processes, providing a pure CO2 flow that can be stored or utilized. Compared to storage, carbon capture and utilization (CCU) technologies deliver valuable carbon-based products required to sustain human activities. The valorization of green CO2 could aid the transition towards defossilization of the economy. Indeed, several CO2 utilization technologies could be incorporated into biomethane production systems, but there is still a limited understanding of the available alternatives and their potential impacts on biomethane systems.This thesis aims to investigate the integration of CO2 utilization technologies in biomethane production systems by revealing its potential, identifying alternatives, and assessing the impacts of the integration. Using Sweden as an example, scenarios of future biomethane production were employed to estimate the potential CO2 available for utilization. To complement the analysis, a qualitative approach made possible the identification of aspects that could affect CO2 utilization in biomethane production. Moreover, a multi-criteria analysis (MCA) framework was developed to identify relevant indicators for assessment and available alternatives for CO2 utilization. The research also includes a life cycle assessment (LCA) to evaluate the climate performance of relevant CCU alternatives in the biomethane production system.Results show that 160 kt of CO2 could be obtained from biomethane production in Sweden, which could potentially increase threefold from 2020 to 2030. The evaluation of alternatives for CO2 utilization includes environmental, technical, economic, and social criteria with sound indicators within an MCA framework. Indicators to evaluate each criterion provide valuable information to identify feasible and sustainable alternatives that can be integrated into biomethane plants. The identified alternatives with a high readiness level are additional methane through methanation, horticulture, mineral carbonates, fuels, pH control, bulk chemicals, and liquefied CO2 for direct use. The results provide information to decision-makers in relation to considerations to take before implementation, like energy requirements, the existence of regulations and standards, and uncertainty. In terms of the climate performance of biomethane with the inclusion of CCU alternatives, the results show a possible reduction of CO2 emissions that depends on the possibility of substituting fossil-based products. The investigated alternatives all result in lower emissions, but concrete curing and methanation using renewable hydrogen produce the best results.To conclude, the potential future increase of green CO2 from biomethane in Sweden creates opportunities to substitute fossil carbon in current applications and mature conversion pathways. Moreover, the inclusion of CCU in biomethane production contributes to reducing biomethane system emissions and diversifying its products. Possible alternatives of CCU that can be integrated into biomethane production systems in the short term include methanation and concrete curing. Other alternatives could be possible but present lower performance and higher uncertainties at the moment.
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| 4. |
- Cordova, Stephanie, 1988-, et al.
(författare)
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What should we do with CO₂ from biogas upgrading?
- 2023
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Ingår i: Journal of CO2 Utilization. - : Elsevier. - 2212-9820 .- 2212-9839. ; 77
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Tidskriftsartikel (refereegranskat)abstract
- Carbon capture and utilization has been proposed as an essential climate change mitigation strategy, but only a few implemented cases exist. During biomethane production from anaerobic digestion, CO₂ is commonly separated and emitted into the atmosphere, which can be utilized as raw material for various products. This research aims to identify and assess CO₂ utilization alternatives for possible integration with biogas upgrading from anaerobic digestion by developing a soft multi-criteria analysis (MCA). A literature review complemented with stakeholder participation enabled the identification of relevant alternatives and criteria for assessment. Potential alternatives for CO₂ utilization include methane, mineral carbonates, biomass production, fuels, chemicals, pH control, and liquefied CO₂. Results show that although no alternative performs well in all indicators, there is an opportunity for short-term implementation for methane, biomass production, mineral carbonates, liquefied CO₂, and pH control. Moreover, the uncertainty analysis reveals that even though the technologies have a high technological development, more information on critical aspects is still required. The soft MCA provides information to decision-makers, practitioners, and the academic community on learning opportunities of the alternatives and indicators to step from development into implementation. For instance, the method can be used to assess more specific systems with different locations and scales or to direct efforts to ease the implementation of CCU.
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| 5. |
- Esguerra, John Laurence, 1991-
(författare)
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Developing strategies for improved economic performance and reduced climate impact of landfill mining in Europe
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Landfill mining refers to the re-circulation of resources from the previously deposited wastes. It is an alternative approach for managing landfills that integrates resource recovery with site remediation. Several resources that can be recovered in landfills include scrap metals for recycling, combustibles for energy recovery, and inert materials for construction applications. In addition, land can be recovered for alternative uses, or landfill void space can be liberated for the deposition of future wastes. At present, landfill mining is still an emerging concept with few project implementations. Consequently, the assessments of its economic and climate implications are case study-specific, limiting the understanding of its potential in a wider geographical scope. This thesis aims to assess the economic performance and climate impact of landfill mining in Europe towards the development of sound strategies for implementation. Different project setups are assessed in relation to varying factors at the site level such as waste composition and landfill settings, and at the system level such as policy and market conditions and background material and energy. In doing so, a factor-based method is developed and applied to generate multiple scenarios (531, 441 scenarios per project setup) and determine the underlying important factors and their interrelations that drive the results. Such understanding is used to develop and discuss strategies for improvement by addressing relevant questions for specific stakeholders, including project investors (i.e., which landfill sites to prioritize?), landfill mining practitioners (i.e., how to set up such projects?), and policymakers (i.e., which policy instruments can effectively support such projects?). Results show that landfill mining is preferable in terms of climate than economy. In general, about 50% of the scenarios are climate beneficial, while only about 20% of the scenarios are profitable. Possible economic and climate improvements are shown by employing internal thermal treatment of combustibles and extending fines residue utilization as construction aggregates. However, these require overarching conditions such that the choice of project setup must be in line with the selection of landfills for mining. Preferable site and system-level conditions are identified in general but it is also discussed that the plausibility of finding such conditions may be difficult at present. This steers the development of more tailored strategies on what can be done now by the landfill practitioners in terms of setting up projects under current policy and market conditions in specific regions, or what can be done by the policymakers in terms of implementing various policy instruments that can drive such changes at the system level. In this regard, the future of landfill mining research can be guided towards addressing key challenges and potential solutions for improvement elicited through a generic and learning-oriented assessment. Furthermore, this thesis highlights the role of assessment as a tool for learning and guiding the development of emerging concepts such as landfill mining.
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| 6. |
- Esguerra, John Laurence, 1991-
(författare)
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Economics of Landfill Mining : Usefulness and Validity of Different Assessment Approaches
- 2020
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Landfill mining (LFM) is an alternative strategy to manage landfills that integrates remediation with secondary resource recovery. At present, LFM remains as an emerging concept with a few pilot-scale project implementations, which presents challenges when assessing its economic performance. These challenges include large knowledge deficits about the individual processes along the LFM process chain, lack of know-how in terms of project implementation and economic drivers, and limited applicability of results to specific case studies. Based on how these challenges were addressed, this thesis aims to analyze the usefulness and validity of different economic assessments of LFM towards the provision of better support for decision-making and in-depth learning for the development of cost-efficient projects. Different studies were analyzed including the previous studies through a systematic literature review and the factor-based method that is developed in this thesis. Four categories of economic assessment approaches were derived in terms of the study object that is about either an individual LFM project (case-study specific) or multiple LFM projects in a region (generic); and in terms of the extent of analysis that is about either the identification of the net economic potential (decision-oriented) or extended towards an in-depth learning of what builds up such result (learning-oriented). Across the different approaches, most of the previous studies have questionable usefulness and validity. The unaddressed parametric uncertainties exclude the influence of using inherently uncertain input data due to large knowledge deficits. While the narrowly accounted scenario uncertainties limits the fact that LFM can be done in various ways and settings in terms of site selection, project set-up and regulatory and market conditions. In essence, these uncertainties propagate from case-study specific to generic study object. From decision-oriented to learning-oriented studies, the identification of what builds up the result are unsystematically determined that raises issues on their subsequent recommendations for improvement based on superficially derived economic drivers. The factor-based method, with exploratory scenario development and global sensitivity analysis, is presented as an approach to performing generic and learning-oriented studies. As for general recommendations, applied research is needed to aid large knowledge deficits, methodological rigor is needed to account for uncertainties and systematically identify economic drivers, and learningoriented assessment is needed to facilitate future development of LFM. This thesis highlights the important role of economic assessments, which is not only limited for the assessment of economic potential but also for learning and guiding the development of emerging concepts such as LFM.
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| 7. |
- Gustafsson, Marcus, 1987-, et al.
(författare)
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Cleaner heavy transports : Environmental and economic analysis of liquefied natural gas and biomethane
- 2021
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Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 278
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Tidskriftsartikel (refereegranskat)abstract
- Looking to reduce climate change impact and particle emissions, the heavy-duty transport sector is moving towards a growth within technology and infrastructure for use of liquefied natural gas (LNG). This opens an opportunity for the biogas market to grow as well, especially in the form of liquefied biomethane (LBM). However, there is a need to investigate the economic conditions and the possible environmental benefits of using LBM rather than LNG or diesel in heavy transports. This study presents a comparison of well-to-wheel scenarios for production, distribution and use of LBM, LNG and diesel, assessing both environmental and economic aspects in a life cycle perspective. The results show that while LNG can increase the climate change impact compared to diesel by up to 10%, LBM can greatly reduce the environmental impact compared to both LNG and diesel. With a German electricity mix, the climate change impact can be reduced by 45 – 70% compared to diesel with LBM from manure, and by 50 – 75% with LBM from food waste. If digestate is used to replace mineral fertilizer, the impact of LBM can even be less than 0. However, the results vary a lot depending on the type of feedstock, the electricity system and whether the calculations are done according to RED or ISO guidelines. Economically, it can be hard for LBM to compete with LNG, due to relatively high production costs, and some form of economic incentives are likely required.
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| 8. |
- Gustafsson, Marcus, 1987-, et al.
(författare)
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Climate performance of liquefied biomethane with carbon dioxide utilization or storage
- 2024
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Ingår i: Renewable and sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 192
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Tidskriftsartikel (refereegranskat)abstract
- In the process of upgrading biogas to biomethane for gas grid injection or use as a vehicle fuel, biogenic carbon dioxide (CO₂) is separated and normally emitted to the atmosphere. Meanwhile, there are a number of ways of utilizing CO₂ to reduce the dependency on fossil carbon sources. This article assesses the climate performance of liquefied biomethane for road transport with different options for utilization or storage of CO₂. The analysis is done from a life cycle perspective, covering the required and avoided processes from biogas production to the end use of biomethane and CO₂. The results show that all of the studied options for CO₂ utilization can improve the climate performance of biomethane, in some cases contributing to negative CO₂ emissions. One of the best options, from a climate impact perspective, is to use the CO₂ internally to produce more methane, although continuous supply of hydrogen from renewable sources can be a challenge. Another option that stands out is concrete curing, where CO₂ can both replace conventional steam curing and be stored for a long time in mineral form. Storing CO₂ in geological formations can also lead to negative CO₂ emissions. However, with such long-term storage solutions, opportunities to recycle biogenic CO₂ are lost, together with the possibility of de-fossilizing processes that require carbon, such as chemical production and horticulture.
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| 9. |
- Gustafsson, Marcus, 1987-, et al.
(författare)
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Scenarios for upgrading and distribution of compressed and liquefied biogas : Energy, environmental, and economic analysis
- 2020
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Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 256
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Tidskriftsartikel (refereegranskat)abstract
- In the transition towards fossil-free transports, there is an increasing interest in upgraded biogas, or biomethane, as a vehicle fuel. Liquefied biogas has more than twice as high energy density as compressed biogas, which opens up the opportunity for use in heavy transports and shipping and for more efficient distribution. There are several ways to produce and distribute compressed and liquefied biogas, but very few studies comparing them and providing an overview. This paper investigates the energy balance, environmental impact and economic aspects of different technologies for upgrading, liquefaction and distribution of biogas for use as a vehicle fuel. Furthermore, liquefaction is studied as a method for efficient long-distance distribution.The results show that the differences between existing technologies for upgrading and liquefaction are small in a well-to-tank perspective, especially if the gas is transported over a long distance before use. Regarding distribution, liquefaction can pay back economically after 25–250 km compared to steel container trailers with compressed gas, and reduce the climate change impact after 10–30 km. Distribution in gas grid is better in all aspects, given that it is available and no addition of propane is required. Liquefaction can potentially expand the geographical boundaries of the market for biogas as a vehicle fuel, and cost reductions resulting from technology maturity allow cost-effective liquefaction even at small production capacities.
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| 10. |
- Gustafsson, Marcus, 1987-, et al.
(författare)
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Well-to-wheel climate performance of gas and electric vehicles in Europe
- 2021
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Ingår i: Transportation Research Part D. - : Elsevier. - 1361-9209 .- 1879-2340. ; 97
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Tidskriftsartikel (refereegranskat)abstract
- Focusing on tailpipe emissions, current EU policies do not favor the use of biofuels in transports. This paper analyzes the well-to-wheel climate performance of gas and electric vehicles in Europe, taking into account the share of biomethane in vehicle gas as well as the production systems for biomethane and electricity in different countries. The results show that both gas and electric vehicles can significantly reduce the climate change impact of transports compared to diesel. In an average European electricity system, electricity has around 30% lower climate impact than diesel for a heavy truck, and 65-70% lower for a passenger car or city bus. Average European vehicle gas reduces the climate impact by up to 28% compared to diesel, or 11% compared to fossil natural gas, and in some countries vehicle gas has lower climate impact than electricity. This demonstrates the importance of not limiting analysis and policy to tailpipe emissions.
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