| 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
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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.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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