| 1. |
- Ahlgren, Serina, et al.
(författare)
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Indirekt förändrad markanvändning och biodrivmedel - en kunskapsöversikt
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Under senare år har det pågått en debatt om biodrivmedels klimatnytta, detta sedan studier visat att indirekt förändrad markanvändning kan leda till stora utsläpp av växthusgaser. Ökad produktion av biodrivmedel i ett land kan leda till att annan produktion trängs undan, vilket i förlängningen kan leda till omvandling av skogs- eller betesmark till jordbruksmark i andra länder; detta benämns ofta som biodrivmedlets indirekta markanvändning (förkortat iLUC efter engelskans indirect land use change). Syftet med denna studie är att sammanställa den stora mängd litteratur som finns om iLUC kopplad till biodrivmedel, att beskriva ett antal av de metoder som finns för att kvantifiera iLUC samt att sammanställa och analysera resultat från litteraturen. Vidare syftar rapporten till att beskriva om och hur iLUC kan integreras i livscykelanalysmetodik vid beräkning av växthusgaser från produktion av biodrivmedel samt respektive ingå i lagstiftning och certifiering. Denna rapport visar att det finns många olika modeller för att kvantifiera iLUC, med väldigt varierande resultat. Skillnaderna i resultat beror på att modellerna har olika struktur och antaganden. I rapporten påvisas även problematiken med att koppla samman iLUC-modeller med livscykelanalysberäkningar. Alternativa sätt att hantera iLUC-frågan diskuteras också.
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| 2. |
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| 3. |
- 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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| 4. |
- Alvfors, Per, 1954-, et al.
(författare)
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Research and development challenges for Swedish biofuel actors – three illustrative examples : Improvement potential discussed in the context of Well-to-Tank analyses
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Currently biofuels have strong political support, both in the EU and Sweden. The EU has, for example, set a target for the use of renewable fuels in the transportation sector stating that all EU member states should use 10% renewable fuels for transport by 2020. Fulfilling this ambition will lead to an enormous market for biofuels during the coming decade. To avoid increasing production of biofuels based on agriculture crops that require considerable use of arable area, focus is now to move towards more advanced second generation (2G) biofuels that can be produced from biomass feedstocks associated with a more efficient land use. Climate benefits and greenhouse gas (GHG) balances are aspects often discussed in conjunction with sustainability and biofuels. The total GHG emissions associated with production and usage of biofuels depend on the entire fuel production chain, mainly the agriculture or forestry feedstock systems and the manufacturing process. To compare different biofuel production pathways it is essential to conduct an environmental assessment using the well-to-tank (WTT) analysis methodology. In Sweden the conditions for biomass production are favourable and we have promising second generation biofuels technologies that are currently in the demonstration phase. In this study we have chosen to focus on cellulose based ethanol, methane from gasification of solid wood as well as DME from gasification of black liquor, with the purpose of identifying research and development potentials that may result in improvements in the WTT emission values. The main objective of this study is thus to identify research and development challenges for Swedish biofuel actors based on literature studies as well as discussions with the the researchers themselves. We have also discussed improvement potentials for the agriculture and forestry part of the WTT chain. The aim of this study is to, in the context of WTT analyses, (i) increase knowledge about the complexity of biofuel production, (ii) identify and discuss improvement potentials, regarding energy efficiency and GHG emissions, for three biofuel production cases, as well as (iii) identify and discuss improvement potentials regarding biomass supply, including agriculture/forestry. The scope of the study is limited to discussing the technologies, system aspects and climate impacts associated with the production stage. Aspects such as the influence on biodiversity and other environmental and social parameters fall beyond the scope of this study. We find that improvement potentials for emissions reductions within the agriculture/forestry part of the WTT chain include changing the use of diesel to low-CO2-emitting fuels, changing to more fuel-efficient tractors, more efficient cultivation and manufacture of fertilizers (commercial nitrogen fertilizer can be produced in plants which have nitrous oxide gas cleaning) as well as improved fertilization strategies (more precise nitrogen application during the cropping season). Furthermore, the cultivation of annual feedstock crops could be avoided on land rich in carbon, such as peat soils and new agriculture systems could be introduced that lower the demand for ploughing and harrowing. Other options for improving the WTT emission values includes introducing new types of crops, such as wheat with higher content of starch or willow with a higher content of cellulose. From the case study on lignocellulosic ethanol we find that 2G ethanol, with co-production of biogas, electricity, heat and/or wood pellet, has a promising role to play in the development of sustainable biofuel production systems. Depending on available raw materials, heat sinks, demand for biogas as vehicle fuel and existing 1G ethanol plants suitable for integration, 2G ethanol production systems may be designed differently to optimize the economic conditions and maximize profitability. However, the complexity connected to the development of the most optimal production systems require improved knowledge and involvement of several actors from different competence areas, such as chemical and biochemical engineering, process design and integration and energy and environmental systems analysis, which may be a potential barrier.
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| 5. |
- Alvors, Per, et al.
(författare)
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Research and development challenges for Swedish biofuel actors – three illustrative examples : Improvement potential discussed in the context of Well-to-Tank analyses
- 2010
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Currently biofuels have strong political support, both in the EU and Sweden. The EU has, for example, set a target for the use of renewable fuels in the transportation sector stating that all EU member states should use 10% renewable fuels for transport by 2020. Fulfilling this ambition will lead to an enormous market for biofuels during the coming decade. To avoid increasing production of biofuels based on agriculture crops that require considerable use of arable area, focus is now to move towards more advanced second generation (2G) biofuels that can be produced from biomass feedstocks associated with a more efficient land use.Climate benefits and greenhouse gas (GHG) balances are aspects often discussed in conjunction with sustainability and biofuels. The total GHG emissions associated with production and usage of biofuels depend on the entire fuel production chain, mainly the agriculture or forestry feedstock systems and the manufacturing process. To compare different biofuel production pathways it is essential to conduct an environmental assessment using the well-to-tank (WTT) analysis methodology.In Sweden the conditions for biomass production are favourable and we have promising second generation biofuels technologies that are currently in the demonstration phase. In this study we have chosen to focus on cellulose based ethanol, methane from gasification of solid wood as well as DME from gasification of black liquor, with the purpose of identifying research and development potentials that may result in improvements in the WTT emission values. The main objective of this study is thus to identify research and development challenges for Swedish biofuel actors based on literature studies as well as discussions with the the researchers themselves. We have also discussed improvement potentials for the agriculture and forestry part of the WTT chain. The aim of this study is to, in the context of WTT analyses, (i) increase knowledge about the complexity of biofuel production, (ii) identify and discuss improvement potentials, regarding energy efficiency and GHG emissions, for three biofuel production cases, as well as (iii) identify and discuss improvement potentials regarding biomass supply, including agriculture/forestry. The scope of the study is limited to discussing the technologies, system aspects and climate impacts associated with the production stage. Aspects such as the influence on biodiversity and other environmental and social parameters fall beyond the scope of this study.We find that improvement potentials for emissions reductions within the agriculture/forestry part of the WTT chain include changing the use of diesel to low-CO2-emitting fuels, changing to more fuel-efficient tractors, more efficient cultivation and manufacture of fertilizers (commercial nitrogen fertilizer can be produced in plants which have nitrous oxide gas cleaning) as well as improved fertilization strategies (more precise nitrogen application during the cropping season). Furthermore, the cultivation of annual feedstock crops could be avoided on land rich in carbon, such as peat soils and new agriculture systems could be introduced that lower the demand for ploughing and harrowing. Other options for improving the WTT emission values includes introducing new types of crops, such as wheat with higher content of starch or willow with a higher content of cellulose.From the case study on lignocellulosic ethanol we find that 2G ethanol, with co-production of biogas, electricity, heat and/or wood pellet, has a promising role to play in the development of sustainable biofuel production systems. Depending on available raw materials, heat sinks, demand for biogas as vehicle fuel and existing 1G ethanol plants suitable for integration, 2G ethanol production systems may be designed differently to optimize the economic conditions and maximize profitability. However, the complexity connected to the development of the most optimal production systems require improved knowledge and involvement of several actors from different competence areas, such as chemical and biochemical engineering, process design and integration and energy and environmental systems analysis, which may be a potential barrier.Three important results from the lignocellulosic ethanol study are: (i) the production systems could be far more complex and intelligently designed than previous studies show, (ii) the potential improvements consist of a large number of combinations of process integration options wich partly depends on specific local conditions, (iii) the environmental performance of individual systems may vary significantly due to systems design and local conditons.From the case study on gasification of solid biomass for the production of biomethane we find that one of the main advantages of this technology is its high efficiency in respect to converting biomass into fuels for transport. For future research we see a need for improvements within the gas up-grading section, including gas cleaning and gas conditioning, to obtain a more efficient process. A major challenge is to remove the tar before the methanation reaction.Three important results from the biomethane study are: (i) it is important not to crack the methane already produced in the syngas, which indicates a need for improved catalysts for selective tar cracking, (ii) there is a need for new gas separation techniques to facilitate the use of air oxidation agent instead of oxygen in the gasifier, and (iii) there is a need for testing the integrated process under realistic conditions, both at atmospheric and pressurized conditions.From the case study on black liquor gasification for the production of DME we find that the process has many advantages compared to other biofuel production options, such as the fact that black liquor is already partially processed and exists in a pumpable, liquid form, and that the process is pressurised and tightly integrated with the pulp mill, which enhances fuel production efficiency. However, to achieve commercial status, some challenges still remain, such as demonstrating that materials and plant equipment meet the high availability required when scaling up to industrial size in the pulp mill, and also proving that the plant can operate according to calculated heat and material balances. Three important results from the DME study are: (i) that modern chemical pulp mills, having a potential surplus of energy, could become important suppliers of renewable fuels for transport, (ii) there is a need to demonstrate that renewable DME/methanol will be proven to function in large scale, and (iii) there is still potential for technology improvements and enhanced energy integration.Although quantitative improvement potentials are given in the three biofuel production cases, it is not obvious how these potentials would affect WTT values, since the biofuel production processes are complex and changing one parameter impacts other parameters. The improvement potentials are therefore discussed qualitatively. From the entire study we have come to agree on the following common conclusions: (i) research and development in Sweden within the three studied 2G biofuel production technologies is extensive, (ii) in general, the processes, within the three cases, work well at pilot and demonstration scale and are now in a phase to be proven in large scale, (iii) there is still room for improvement although some processes have been known for decades, (iv) the biofuel production processes are complex and site specific and process improvements need to be seen and judged from a broad systems perspective (both within the production plant as well as in the entire well-to-tank perspective), and (v) the three studied biofuel production systems are complementary technologies. Futher, the process of conducting this study is worth mentioning as a result itself, i.e. that many different actors within the field have proven their ability and willingness to contribute to a common report, and that the cooperation climate was very positive and bodes well for possible future collaboration within the framework of the f3 center.Finally, judging from the political ambitions it is clear that the demand for renewable fuels will significantly increase during the coming decade. This will most likely result in opportunities for a range of biofuel options. The studied biofuel options all represent 2G biofuels and they can all be part of the solution to meet the increased renewable fuel demand.
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| 6. |
- Andersson, Öivind, et al.
(författare)
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The greenhouse gas emissions of an electrified vehicle combined with renewable fuels: Life cycle assessment and policy implications
- 2021
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619. ; 289, s. 116621-116621
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Tidskriftsartikel (refereegranskat)abstract
- A life cycle assessment is presented for a current vehicle’s greenhouse gas impact when using a combination of electrification and renewable fuels. Three degrees of electrification are considered: a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a battery-electric vehicle. These are combined with fuels with various degrees of renewable content, representing a fossil fuel, a first-generation biofuel and a second-generation biofuel. For charging, the 2020 European electricity mix is used and compared with an electricity mix of low greenhouse-gas intensity. Renewable fuels are found to have a greater potential to reduce the life-cycle greenhouse gas emissions than a low carbon electricity mix. The results are discussed in terms of the supply potential for renewable fuels on the fleet level. It is found that plug-in hybrid vehicles may enable the automotive sector to reach more ambitious climate goals than battery-electric vehicles. An assessment is also made of how the life cycle greenhouse gas emissions compare with the emissions as measured by current policy instruments. The discrepancies indicate that current climate policy instruments are inadequate for minimizing the automotive sector’s climate impact and suggestions for improvements are made.
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| 7. |
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| 8. |
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| 9. |
- Bennich, Therese, 1989-
(författare)
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The transition to a bio-based economy : Toward an integrated understanding
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The bio-based economy has gained increasing attention in societal and academic debates over the past two decades, and is argued to hold solutions to several pressing sustainability challenges. However, it is not yet clear if the high-reaching aspirations of the bio-based economy can be realized. The bio-based economy discourse has been criticized for being promissory, vague, and single-sector focused, thereby overlooking larger systemic impacts, trade-offs, and unintended consequences that may result from pursuing the goals of the bio-based economy. Against this background, this thesis aims to advance an integrated and systemic understanding of the transition to a bio-based economy and what it implies for sustainability. Sweden is used as an empirical case, where specific bio-based economy goals, as well as their interactions and sustainability outcomes, are examined. The focus is primarily on developments in the forestry, agriculture, and energy sectors. The analysis also seeks to identify how goals related to the bio-based economy are interconnected with goals promoted by parallel sustainability initiatives, specifically the 2030 Agenda and the associated Sustainable Development Goals (SDGs). Integration is achieved by using systems analysis tools and methods. Further, the weak and strong sustainability paradigms, and the opposing definitions of sustainability they provide, are used to assess the contribution of the bio-based economy to sustainability. The integrated analysis provides a detailed and operational conceptualization of transition pathways to a Swedish bio-based economy. The goals of the Swedish bio-based economy are divergent and broad-reaching, emphasizing that there is no general agreement on what the transition to a bio-based economy entails. The results point to multiple barriers that need to be addressed to realize the goals of the Swedish bio-based economy. Goal conflicts constitute one such barrier. These are found internal to as well as across the bio-based economy and the parallel 2030 Agenda. Additional hindrances include policy resistance, negative cross-sectoral spillovers, and patterns of path dependency. However, the results also highlight several opportunities for supporting the transition process in a Swedish context. These opportunities include the identification of goals and interventions with synergetic potential, which offer a basis for developing efficient implementation strategies with high systemic impact. There is also large potential to support cross-sectoral collaboration and learning, based on shared interests and challenges. Finally, the results emphasize the importance of better understanding and addressing perceptions about risk, conflict, legitimacy, and trust in the transition process.In terms of the overarching question of what the bio-based economy implies for sustainability, the results find that the bio-based economy has been contributing to developments that align primarily with weak sustainability. From the perspective of the strong sustainability paradigm, the prospects of the bio-based economy are less promising, potentially leading to outcomes that could worsen ongoing environmental and social issues. For the future, fundamental changes to the way the bio-based economy is conceptualized and implemented are needed for it to contribute to sustainability according to the notion of strong sustainability.
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| 10. |
- Berglund, Maria, et al.
(författare)
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Assessment of energy performance in the life-cycle of biogas production
- 2006
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Ingår i: Biomass & Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 30:3, s. 254-266
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Tidskriftsartikel (refereegranskat)abstract
- Energy balances are analysed from a life-cycle perspective for biogas systems based on 8 different raw materials. The analysis is based on published data and relates to Swedish conditions. The results show that the energy input into biogas systems (i.e. large-scale biogas plants) overall corresponds to 20-40% (on average approximately 30%) of the energy content in the biogas produced. The net energy output turns negative when transport distances exceed approximately 200 kin (manure), or up to 700 km (slaughterhouse waste). Large variations exist in energy efficiency among the biogas systems studied. These variations depend both on the properties of the raw materials studied and on the system design and allocation methods chosen. The net energy output from biogas systems based on raw materials that have high water content and low biogas yield (e.g. manure) is relatively low. When energy-demanding handling of the raw materials is required, the energy input increases significantly. For instance, in a ley crop-based biogas system, the ley cropping alone corresponds to approximately 40% of the energy input. Overall, operation of the biogas plant is the most energy-demanding process, corresponding to 40-80% of the energy input into the systems. Thus, the results are substantially affected by the assumptions made about the allocation of a plant's entire energy demand among raw materials, e.g. regarding biogas yield or need of additional water for dilution. (c) 2005 Elsevier Ltd. All rights reserved.
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| 11. |
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| 12. |
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| 13. |
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| 14. |
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| 15. |
- Berndes, Göran, 1966, et al.
(författare)
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Bioenergy and Land Use Change-State of the Art
- 2015
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Ingår i: Advances in Bioenergy: The Sustainability Challenge. - Oxford, UK : John Wiley & Sons, Ltd. - 9781118957875 - 9781118957844 ; , s. 249-271
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Bokkapitel (refereegranskat)abstract
- The dedicated production of biomass crops and the collection of residues in agriculture and forestry can lead to undesirable negative impacts and it is crucial that practices are found that ensure that these impacts are avoided or mitigated as far as possible. This chapter concerns the use of biomass for energy and the connection between increased bioenergy use and land use change (LUC). Land use and LUC associated with bioenergy can lead to a multitude of environmental and socioeconomic consequences. The chapter focuses on the question whether greenhouse gas (GHG) emissions associated with LUC could undermine the climate change mitigation benefits of bioenergy. There are, however, several options for mitigating these emissions that can be implemented: development of bioenergy feedstock production systems that integrate with existing agriculture and forestry production, enhancement of land use productivity in agriculture and forestry in general, and legal protection of natural ecosystems.
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| 16. |
- Berndes, Göran, 1966, et al.
(författare)
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Bioenergy and land use change-state of the art
- 2013
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Ingår i: Wiley Interdisciplinary Reviews: Energy and Environment. - : Wiley. - 2041-8396 .- 2041-840X. ; 2:3, s. 282-303
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Forskningsöversikt (refereegranskat)abstract
- Bioenergy projects can lead to direct and indirect land use change (LUC), which can substantially affect greenhouse gas balances with both beneficial and adverse outcomes for bioenergy's contribution to climate change mitigation. The causes behind LUC are multiple, complex, interlinked, and change over time. This makes quantification uncertain and sensitive to many factors that can develop in different directions-including land use productivity, trade patterns, prices and elasticities, and use of by-products associated with biofuels production. Quantifications reported so far vary substantially and do not support the ranking of bioenergy options with regard to LUC and associated emissions. There are however several options for mitigating these emissions, which can be implemented despite the uncertainties. Long-rotation forest management is associated with carbon emissions and sequestration that are not in temporal balance with each other and this leads to mitigation trade-offs between biomass extraction for energy use and the alternative to leave the biomass in the forest. Bioenergy's contribution to climate change mitigation needs to reflect a balance between near-term targets and the long-term objective to hold the increase in global temperature below 2 degrees C (Copenhagen Accord). Although emissions from LUC can be significant in some circumstances, the reality of such emissions is not sufficient reason to exclude bioenergy from the list of worthwhile technologies for climate changemitigation. Policy measures to minimize the negative impacts of LUC should be based on a holistic perspective recognizing the multiple drivers and effects of LUC.
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| 17. |
- Berndes, Göran, 1966, et al.
(författare)
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Bioenergy for climate stabilization
- 2004
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Ingår i: Bioenergy International. ; :no 9, May, s. 5-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 18. |
- Berndes, Göran, 1966, et al.
(författare)
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Cadmium accumulation and Salix-based phytoextraction on arable land in Sweden
- 2004
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Ingår i: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 103:1, s. 207-223
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Tidskriftsartikel (refereegranskat)abstract
- Cadmium accumulation in arable soils causes concern due to possible direct environmental effects and health risks associated with exposure of humans to cadmium through agricultural products. This paper discusses the problem of cadmium accumulation in Swedish arable land, and evaluates Salix (Salix vinimalis) cultivation as a tool for addressing the problem. It is found that Salix cultivation offers an effective option for addressing the cadmium accumulation, especially when the topsoil has high cadmium content due to anthropogenic inflows, and the subsoil naturally contains little cadmium. The estimated practical potential for Salix-based cadmium management (ca. 490 000 ha) is very large compared to the present Salix plantation area in Sweden (ca. 15 000 ha). However, the estimates of the net economic value of cadmium removal from arable land indicate that the economics of Salix production will not improve dramatically due to an induced cadmium removal. Salix-based cadmium management will therefore most likely take place in counties where Salix cultivation can be expected to expand as a response to an unfilled biomass demand in the energy sector. © 2003 Elsevier B.V. All rights reserved.
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| 19. |
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| 20. |
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| 21. |
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| 22. |
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| 23. |
- Berndes, Göran, 1966, et al.
(författare)
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Multifunctional biomass production systems - an overview with presentation of specific applications in India and Sweden
- 2008
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Ingår i: Biofuels, Bioproducts and Biorefining. - : Wiley. - 1932-104X .- 1932-1031. ; 2:1, s. 16-25
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Tidskriftsartikel (refereegranskat)abstract
- This perspective discusses multi-functional biomass production systems, which are located, designed, integrated and managed so as to provide specific environmental services, in addition to biomass supply. Besides discussing the general concept and outlining a range of different possible applications, we present in somewhat more detail specific applications of such systems for the cases of Sweden and India. The overall conclusion is that the environmental benefits from a large-scale establishment of multi-functional biomass production systems could be substantial. Given that suitable mechanisms to put a premium on the provided environmental services can be identified and implemented, additional revenues can be linked to biomass production systems and this could enhance the socioeconomic attractiveness and significantly improve the competitiveness of the produced biomass on the market. The provision of additional environmental services also contributes to local sustainable development, which is in many cases a prerequisite for local support for the production systems.
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| 24. |
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| 25. |
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| 26. |
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| 27. |
- Björkman, Max, et al.
(författare)
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Balancing Different Environmental Effects of Forest Residue Recovery in Sweden - A Stepwise Handling Procedure
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- An increased use of forest fuels is important in the reduction of our dependence on fossil fuels and in attempting to mitigate climate change. However, an increased use will also result in an intensified forestry. Recovery of forest residues (logging residues and stumps) results in a higher pressure on the forest ecosystems and adds environmental effects to those already existing in conventional forestry of stem-wood harvest. The purpose of this study is to use current research on forest residue recovery and its environmental effects and suggest an approach to how these potential positive and negative effects can be balanced. For this task suitable environmental system analysis tools are identified, as well as relevant environmental quality objectives that are connected to the forestry operation. The report suggests an environmental evaluation model in which environmental impact assessment is the fundamental part to balance local and regional effects, such as acidification, eutrophication and biodiversity. Life cycle assessment is integrated to consider global effects, such as greenhouse gas performance. Relevant environmental quality objectives are used as a measure where the compatibility between the recovery of forest residues and the development of the environmental objectives is assessed. The need for regional/local assessments is stressed as an important aspect regarding the applicability of the model, as well as improved preciseness of the environmental quality objectives utilised.
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| 28. |
- Björnsson, Lovisa, et al.
(författare)
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Bioolja från befintliga kraftvärmeverk-en systemstudie : Sammanfattning av ett forskningssamarbete mellan Lunds Tekniska Högskola, Karlstad universitet och Kraftringen Energi
- 2021. - Rapport 123
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Rapport (populärvet., debatt m.m.)abstract
- Samhällets pågående omställning mot minskade utsläpp av växthusgaser kräver bland annat stora mängder fasta biobränslen och flytande biodrivmedel. Den svenska biobränslepotentialen domineras av bi- och restprodukter från skogen, som sågspån från sågverken och grenar och toppar (sk grot) från avverkning av skog. Att omvandla trä till flytande bränslen med hög omvandlingseffektivitet är utmanande, och kräver kommersialisering av ny och innovativ teknik. Behovet av flytande biodrivmedel i transportsektorn har därför hittills framför allt tillgodosetts genom import. Ett utökat och resurseffektivt utnyttjande av den inhemska potentialen av biomassa från skogen skulle kunna vara en viktig komponent i att nå både målet om ett fossilfritt samhälle och mål om miljömässig hållbarhet och spårbarhet för råvaran. Kraftvärmesektorn är i stora delar redan fossilfri och hanterar redan idag inhemska fasta bio-bränslen från skogen. I befintliga kraftvärmeverk finns potential för ökad nyttjandegrad av anläggningen, en befintlig infrastruktur för bränslehantering och möjlighet till värmeavsättning i fjärrvärmenät. Detta skapar förutsättningar för att i tillägg till el och värme komplettera med processer för produktion av flytande energibärare från inhemska, spårbara och hållbara biobränslen från skogen.I denna skrift sammanfattas ett forskningsprojekt där möjligheten att vidareutveckla en befintlig kraftvärmeanläggning genom integrerad produktion av pyrolysolja undersökts. Vi har ställt oss frågor som: Kan vi åstadkomma inhemsk produktion av flytande bränsle från skogsbaserade fasta biobränslen genom att kraftvärmeproduktion kombineras med pyrolysoljeproduktion? Kan detta förbättra konkurrenskraften för kraftvärmeverket vid ett framtida vikande behov av fjärrvärme inom bostadssektorn? Vad innebär möjligheten att bli producent av pyrolysolja både för egen förbrukning och för andra marknader som transportsektorn, för kraftvärmeverket och för klimatet?
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| 29. |
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| 30. |
- Björnsson, Lovisa, et al.
(författare)
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Integrating bio-oil production from wood fuels to an existing heat and power plant - evaluation of energy and greenhouse gas performance in a Swedish case study
- 2021
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Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388 .- 2213-1396. ; 48
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Tidskriftsartikel (refereegranskat)abstract
- Combined heat and power (CHP) production in combination with a district heating (DH) grid gives an energy efficient use of wood fuels. The heat demand in the DH grid will, however, decline in the coming decades, and operators are seeking additional heat sinks. In this case study, the integration of a pyrolysis unit into an existing CHP plant was investigated as a possible solution. The retrofitted pyrolysis unit makes use of excess heat and yields a liquid bio-oil. Pyrolysis integrated with CHP production was shown to give a net energy yield of at least 80%, and to decrease the net heat output to the DH grid. The carbon footprint of the delivered heat was very low at maximum 1.6 g CO(2)eq/MJ. Prolonging the operation of the pyrolysis unit to periods without heat delivery to the DH grid would increase the use of existing installations, but at the cost of energy yields decreasing to 63-70%. Up to 2.8 PJ(LHV)/yr crude bio-oil could be produced at the investigated CHP plant. The bio-oil was shown to have a low carbon footprint, 1.7-4.0 g CO(2)eq/MJ(LHV), which makes it attractive for the rapidly expanding transport biofuel market.
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| 31. |
- Börjesson, Pål, et al.
(författare)
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Agricultural crop-based biofuels - resource efficiency and environmental performance including direct land use changes
- 2011
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 19:2-3, s. 108-120
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Tidskriftsartikel (refereegranskat)abstract
- This paper analyses biofuels from agricultural crops in northern Europe regarding area and energy efficiency, greenhouse gases and eutrophication. The overall findings are that direct land use changes have a significant impact on GHG balances and eutrophication for all biofuels, the choice of calculation methods when by-products are included affecting the performance of food crop-based biofuels considerably, and the technical design of production systems may in specific cases be of major importance. The presented results are essential knowledge for the development of certification systems. Indirect land use changes are recognised but not included due to current scientific and methodological deficiencies. (C) 2010 Elsevier Ltd. All rights reserved.
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| 32. |
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| 33. |
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| 34. |
- Börjesson, Pål, et al.
(författare)
-
Bioenergins historik och framtid
- 2024
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Ingår i: Perspektiv på bioenergi : Biomassans framtida roll i en föränderlig värld - Biomassans framtida roll i en föränderlig värld. - 1102-3651. - 9789186961596 ; :Rapport Nr 133, s. 13-19
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 35. |
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| 36. |
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| 37. |
- Börjesson, Pål, et al.
(författare)
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Biogas as a resource-efficient vehicle fuel
- 2008
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Ingår i: Trends in Biotechnology. - : Elsevier BV. - 0167-7799. ; 26:1, s. 7-13
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Tidskriftsartikel (refereegranskat)abstract
- There are currently strong incentives for increased use of renewable fuels in the transport sector worldwide. However, some bioethanol and biodiesel production routes have limitations with regard to resource efficiency and reduction of greenhouse gases. More efficient biofuel systems are those based on lignocelluloses and novel conversion technologies. A complementary strategy to these is to increase the production of biogas from the digestion of organic residues and energy crops, or from byproducts of ethanol and biodiesel production. Compared with other biomass-based vehicle fuels available so far, biogas often has several advantages from an environmental and resource-efficiency perspective. This provides the motivation for further technological development aiming to reduce costs and thereby increased economic competitiveness of biogas as a vehicle fuel.
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| 38. |
- Börjesson, Pål
(författare)
-
Biogas from waste materials as transportation fuel-benefits from an environmental point of view.
- 2008
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 57:2, s. 271-275
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Tidskriftsartikel (refereegranskat)abstract
- In this paper various biogas systems based on waste materials have been analysed from an environmental point of view. The analyses are based on Swedish conditions using a systems analysis approach from an energy and life cycle perspective. The biogas produced is used as a transportation fuel replacing petrol in light-duty vehicles. The overall aims are to quantify the potential environmental effects when current waste handling and transportation fuel systems are replaced. A general conclusion is that the indirect environmental benefits (e.g. reduced emissions of ammonia and methane, and nitrogen leaching) from altered handling of organic waste materials and land-use may often significantly exceed the direct environmental benefits achieved when biogas replaces petrol (e.g. reduced emissions of carbon dioxide and air pollutants). Such indirect benefits are seldom considered when biogas is evaluated from an environmental point of view. However, the environmental impact from different biogas systems can vary significantly due to factors such as the waste materials utilised, different reference systems being replaced, and local conditions.
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| 39. |
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| 40. |
- Börjesson, Pål
(författare)
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Biomass in a Sustainable Energy System
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The increased use of biomass for energy is as a key strategy in reducing carbon dioxide (CO2) emission, which represents the largest anthropogenic contribution to the greenhouse effect. In this thesis, aspects of an increase in the utilisation of biomass in the Swedish energy system are treated. Modern bioenergy systems should be based on high energy and land-use efficiency since biomass resources and productive land are limited. The energy input, including transportation, per unit biomass produced is about 4-5% for logging residues, straw and short-rotation forest (Salix). Salix has the highest net energy yield per hectare among the various energy crops cultivated in Sweden (Article I). The CO2 emissions from the production and transportation of logging residues, straw and Salix, are equivalent to 2-3% of those from a complete fuel-cycle for coal (Article II). Substituting biomass for fossil fuels in electricity and heat production is, in general, less costly and leads to a greater CO2 reduction per unit biomass than substituting biomass-derived transportation fuels for petrol or diesel. Transportation fuels produced from cellulosic biomass provide larger and less expensive CO2-emission reductions than transportation fuels from annual crops (Article III). Biomass has the potential to become the dominating energy source in Sweden. The current use of about 80 TWh/yr could increase to about 200 TWh/yr, taking into account estimated production conditions around 2015. Swedish CO2 emissions could be reduced by about 50% from the present level if fossil fuels are replaced and the energy demand is unchanged (Articles III and IV). There is a good balance between potential regional production and utilisation of biomass in Sweden. Future biomass transportation distances need not be longer than, on average, about 40 km. About 22 TWh electricity could be produced annually from biomass in large district heating systems by cogeneration (Article IV). Cultivation of Salix and energy grass could be utilised to reduce the negative environmental impact of current agricultural practices, such as the emission of greenhouse gases, nutrient leaching, decreased soil fertility and erosion, and for the treatment of municipal waste water and sludge, leading to increased recirculation of nutrients (Article V). About 20 TWh biomass could theoretically be produced per year at an average cost of less than 50% of current production cost, if the economic value of these local environmental benefits is included (Article VI).
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| 41. |
- Börjesson, Pål, et al.
(författare)
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Biomass Transportation
- 1996
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Ingår i: Renewable Energy. - : Elsevier BV. - 0960-1481. ; 9:1-4, s. 1033-1036, s. 1033-1036
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Tidskriftsartikel (refereegranskat)abstract
- Extensive utilisation of logging residues, straw, and energy crops will lead to short transportation distances and thus low transportation costs. The average distance of transportation of biomass to a large-scale conversion plant, suitable for electricity or methanol production using 300 000 dry tonne biomass yearly, will be about 30 km in Sweden, if the conversion plant is located at the centre of the biomass production area. The estimated Swedish biomass potential of 430 PJ/yr is based on production conditions around 2015, assuming that 30% of the available arable land is used for energy crop production. With present production conditions, resulting in a biomass potential of 220 PJ/yr, the transportation distance is about 42 km. The cost of transporting biomass 30-42 km will be equivalent to 20-25% of the total biomass cost. The total energy efficiency of biomass production and transportation will be 95-97%, where the energy losses from transportation are about 20%. Biomass transportation will contribute less than 10% to the total NOx, CO, and HC emissions from biomass production, transportation, and conversion.
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| 42. |
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| 43. |
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| 44. |
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| 45. |
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| 46. |
- Börjesson, Pål
(författare)
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Emissions of CO2 from Biomass Production and Transportation in Agriculture and Forestry
- 1995
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904. ; 37:6-8, s. 1235-1240
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Tidskriftsartikel (refereegranskat)abstract
- Net CO2 emissions have been calculated for the production and transportation of biomass in Swedish agriculture and forestry, using fossil-fuel-based energy inputs. An analysis of how a transition from a fossil-fuel-based energy system to a CO2-neutral biomass-based system would affect the energy efficiency in biomass production and transportation, has also been carried out. Production and transportation of short-rotation forest (Salix), straw, and logging residues exhibited the lowest CO2 emissions per unit energy delivered, equal to about 50% of those from perennial ley crops and 10 to 30% of those from annual food crops. Compared with CO2 emissions from a complete fuel-cycle for coal, net emissions of CO2 from Salix production, including transportation 50 km by truck, are 35 to 40 times lower when fossil-fuel inputs are used. Future increases in yield and technological development are estimated to reduce net CO2 emissions from biomass production by 30 to 50% in a fossil-fuel-based energy system around the year 2015. A transition from a fossil-fuel-based, to a CO2-neutral biomass-based energy system around 2015, is estimated to increase the energy input in biomass production and transportation by about 40% and 20%, respectively, resulting in a decreased net energy output from biomass production (including transportation) by about 4%.
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| 47. |
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| 48. |
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