| 1. |
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Method and models used in the project Pathways to Sustainable European Energy Systems
- 2011
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- This book describes the research that has been carried out during the first period (2006-2010) of the Alliance for Global Sustainability (AGS) project "Pathways to Sustainable European Energy Systems". this interdisciplinary project involves more that 40 researchers and addresses various aspects of the challenges faced in transforming the European energy system. Presented in this book are the energy-related methods and models that originate from different scientific disciplines and traditions and that were applied in the Pathways project. Some of the analytical tools are well-known, well-documented, and widely used in academic research. Others have been developed (or refined) during the Pathways project and are therefore unique. The chapters of this book cover around 30 different methods and models used in the Pathways project and presents an overview of the processes through which the research was conducted and the methods and models were co-ordinated.
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| 2. |
- Eriksson, Gunnar, et al.
(författare)
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Combustion and fuel characterisation of wheat distillers dried grain with solubles (DDGS) and possible combustion applications
- 2012
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Ingår i: Fuel. - : Elsevier. - 0016-2361 .- 1873-7153. ; 102, s. 208-220
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Tidskriftsartikel (refereegranskat)abstract
- The present transition to a sustainable global energy system requires that biomass is increasingly combusted for heat and power production. Agricultural fuels considered include alkali-rich fuels with high phosphorus content. One such fuel is wheat distiller’s dried grain with solubles (wheat DDGS) from wheat-based ethanol production. Further increases in ethanol production may saturate the current market for wheat DDGS as livestock feed, and fuel uses are therefore considered. Fuel properties of wheat DDGS have been determined. The ash content (5.4 ± 1.6 %wt d.s.) is similar to many agricultural fuels. In comparison to most other biomass fuels the sulphur content is high (0.538 ± 0.232 %wt d.s.), and so are the contents of nitrogen (5.1 ± 0.6 %wt d.s.), phosphorus (0.960. ± 0.073 %wt d.s.) and potassium (1.30 ± 0.35 %wt d.s.). To determine fuel-specific combustion properties, wheat DDGS and mixes between wheat DDGS and logging residues (LR 60 %wt d.s. and DDGS 40 %wt d.s.), and wheat straw (wheat straw 50 %wt d.s., DDGS 50 %wt d.s.) were pelletized and combusted in a bubbling fluidised bed combustor (5 kW) and in a pellets burner combustor (20 kW). Pure wheat DDGS powder was also combusted in a powder burner (150 kW). Wheat DDGS had a high bed agglomeration and slagging tendency compared to other biomass fuels, although these tendencies were significantly lower for the mixture with the Ca-rich LR, probably reflecting the higher first melting temperatures of K–Ca/Mg-phosphates compared to K-phosphates. Combustion and co-combustion of wheat DDGS resulted in relatively large emissions of fine particles (<1 μm) for all combustion appliances. For powder combustion PMtot was sixteen times higher than from softwood stem wood. While the Cl concentrations of the fine particles from the the mixture of LR and wheat DDGS in fluidised bed combustion were lower than from combustion of pure LR, the Cl- and P-concentrations were considerably higher from the wheat DDGS mixtures combusted in the other appliances at higher fuel particle temperature. The particles from powder combustion of wheat DDGS contained mainly K, P, Cl, Na and S, and as KPO3 (i.e. the main phase identified with XRD) is known to have a low melting temperature, this suggests that powder combustion of wheat DDGS should be used with caution. The high slagging and bed agglomeration tendency of wheat DDGS, and the high emissions of fine particles rich in K, P and Cl from combustion at high temperature, mean that it is best used mixed with other fuels, preferably with high Ca and Mg contents, and in equipment where fuel particle temperatures during combustion are moderate, i.e. fluidised beds and possibly grate combustors rather than powder combustors.
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| 3. |
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Systems Perspectives on Biorefineries 2013
- 2013
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- Replacing fossil fuels with biomass for the production of energy carriers, materialsand specialty chemicals is a challenge that now confronts humanity. In whichapplications shall we use limited resources of biomass? How can biomass berefined into the products we want? What are the consequences of demanding toomuch? What is an optimal design of a biorefinery? Where should they be located?What policy instruments are required to realise the biorefineries of the future?There is not one final answer to these questions. However, different systems studiescan provide us with complementary pieces of the puzzle. These can be valuableby themselves, or be brought together into a larger and more complex picture.Systems Perspectives on Biorefineries 2013 is an updated edition of SystemsPerspectives on Biorefineries 2012 and contains twelve chapters that address differenttopics related to the immensely important issue of how the world’s biomassresources can, or should, be converted into the goods we need and desire. Thebook is still far from complete, but it is a contribution and a start...
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| 4. |
- Wetterlund, Elisabeth, et al.
(författare)
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Implications of system expansion for the assessment of well-to-wheel CO2 emissions from biomass-based transportation
- 2010
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Ingår i: International Journal of Energy Research. - : Hindawi Limited. - 0363-907X .- 1099-114X. ; 34:13, s. 1136-1154
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we show the effects of expanding the system when evaluating well-to-wheel (WTW) CO2 emissions for biomass-based transportation, to include the systems surrounding the biomass conversion system. Four different cases are considered: DME via black liquor gasification (BLG), methanol via gasification of solid biomass, lignocellulosic ethanol and electricity from a biomass integrated gasification combined cycle (BIGCC) used in a battery-powered electric vehicle (BPEV). All four cases are considered with as well as without carbon capture and storage (CCS). System expansion is used consistently for all flows. The results are compared with results from a conventional WTW study that only uses system expansion for certain co-product flows. It is shown that when expanding the system, biomass-based transportation does not necessarily contribute to decreased CO2 emissions and the results from this study in general indicate considerably lower CO2 mitigation potential than do the results from the conventional study used for comparison. It is shown that of particular importance are assumptions regarding future biomass use, as by expanding the system, future competition for biomass feedstock can be taken into account by assuming an alternative biomass usage. Assumptions regarding other surrounding systems, such as the transportation and the electricity systems are also shown to be of significance. Of the four studied cases without CCS, BIGCC with the electricity used in a BPEV is the only case that consistently shows a potential for CO2 reduction when alternative use of biomass is considered. Inclusion of CCS is not a guarantee for achieving CO2 reduction, and in general the system effects are equivalent or larger than the effects of CCS. DME from BLG generally shows the highest CO2 emission reduction potential for the biofuel cases. However, neither of these options for biomass-based transportation can alone meet the needs of the transport sector. Therefore, a broader palette of solutions, including different production routes, different fuels and possibly also CCS, will be needed.
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| 5. |
- Pardon, Gaspard, 1983-
(författare)
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From Macro to Nano : Electrokinetic Transport and Surface Control
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Today, the growing and aging population, and the rise of new global threats on human health puts an increasing demand on the healthcare system and calls for preventive actions. To make existing medical treatments more efficient and widely accessible and to prevent the emergence of new threats such as drug-resistant bacteria, improved diagnostic technologies are needed. Potential solutions to address these medical challenges could come from the development of novel lab-on-chip (LoC) for point-of-care (PoC) diagnostics.At the same time, the increasing demand for sustainable energy calls for the development of novel approaches for energy conversion and storage systems (ECS), to which micro- and nanotechnologies could also contribute.This thesis has for objective to contribute to these developments and presents the results of interdisciplinary research at the crossing of three disciplines of physics and engineering: electrokinetic transport in fluids, manufacturing of micro- and nanofluidic systems, and surface control and modification. By combining knowledge from each of these disciplines, novel solutions and functionalities were developed at the macro-, micro- and nanoscale, towards applications in PoC diagnostics and ECS systems.At the macroscale, electrokinetic transport was applied to the development of a novel PoC sampler for the efficient capture of exhaled breath aerosol onto a microfluidic platform.At the microscale, several methods for polymer micromanufacturing and surface modification were developed. Using direct photolithography in off-stoichiometry thiol-ene (OSTE) polymers, a novel manufacturing method for mold-free rapid prototyping of microfluidic devices was developed. An investigation of the photolithography of OSTE polymers revealed that a novel photopatterning mechanism arises from the off-stoichiometric polymer formulation. Using photografting on OSTE surfaces, a novel surface modification method was developed for the photopatterning of the surface energy. Finally, a novel method was developed for single-step microstructuring and micropatterning of surface energy, using a molecular self-alignment process resulting in spontaneous mimicking, in the replica, of the surface energy of the mold.At the nanoscale, several solutions for the study of electrokinetic transport toward selective biofiltration and energy conversion were developed. A novel, comprehensive model was developed for electrostatic gating of the electrokinetic transport in nanofluidics. A novel method for the manufacturing of electrostatically-gated nanofluidic membranes was developed, using atomic layer deposition (ALD) in deep anodic alumina oxide (AAO) nanopores. Finally, a preliminary investigation of the nanopatterning of OSTE polymers was performed for the manufacturing of polymer nanofluidic devices.
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| 6. |
- Sun, Wenjun, 1989, et al.
(författare)
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An alternating D-A1-D-A2 copolymer containing two electron-deficient moieties for efficient polymer solar cells
- 2013
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 1:37, s. 11141-11144
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Tidskriftsartikel (refereegranskat)abstract
- Unlike normal donor-acceptor (D-A) polymers containing only one electron-deficient segment in their repeating unit, the incorporation of two electron-deficient moieties with different absorption behaviors, forming a D-A1-D-A2 internal structure in the alternating copolymer, showed a broader absorption spectrum than its constituent parts and enhanced photovoltaic performance. This work is anticipated to open the door to the design of new low bandgap polymers with a broader absorption range for efficient polymer solar cells.
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| 7. |
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European Energy Pathways - Pathways to sustainable european energy systems
- 2011
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- To meet the challenge of climate change, the world must substaintially reduce emissions of greenhouse gases (GHGs). this must be accomplished in a way that maintains security of supply and competitiveness.This book presents to pathways towards sustainable European energy systems - the "Policy Pathway" and the "Market Pathway". These to pathways differ with respect to where the main responsability lies for transforming the energy system in following the pathway. The Policy pathway takes its departure from the EU Energy and Climate Package, and has a strong focus on targeted policies that promote energy efficiency and energy from renewable sources. The Market Pathway relies more on the market to transform the energy system, and presents a future in which the cost associated with emitting CO2 (and other GHGs) is the dominating policy measure.This book describes the research that has been carried out during the first period (2006-2010) of the AGS project "Pathways to Sustsainable Energy Systems". This interdisciplinary project involved more than 40 researchers and addressed various aspects of the challenges faced in transforming the European energy system. The chapters in this book cover more than 30 topics and presents an overall picture of the results obtained to date from various activities in the Pathways project.
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| 8. |
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Systems Perspectives on Biorefineries 2012
- 2012
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- Replacing fossil fuels with biomass for the production of energy carriers, materials and specialty chemicalsis a challenge that now confronts humanity. In which applications shall we use limited resourcesof biomass? How can biomass be refined into the products we want? What is an optimal design of abiorefinery? How is the most advantageous portfolio of policy instruments designed to realise the biorefineriesof the future?There is not one final answer to these questions. However, different systems studies can provide us withcomplementary pieces of the puzzle. These can be valuable by themselves, or be brought together into alarger and more complex picture. Systems perspectives on Biorefineries 2012 contains nine chapters thataddress different topics related to the immensely important issue of how the world’s biomass resourcescan, or should, be converted into the goods we need and desire. The book is far from complete, but it is acontribution and a start...
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| 9. |
- Kannisto, Hannes, 1979, et al.
(författare)
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Efficient low temperature lean NOx reduction over Ag/Al2O3-A system approach
- 2011
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Ingår i: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 104:1-2, s. 74-83
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Tidskriftsartikel (refereegranskat)abstract
- This study focuses on lean NOx reduction (LNR) by n-octane using silver-alumina based catalysts, with the addition of hydrogen. The work takes a system approach, where parameters such as temperature, reformate gas composition, fuel penalty and realistic monolith samples are considered. The LNR catalyst samples were prepared by impregnation and sol-gel methods and the NOx reduction performance was characterized by flow-reactor experiments, where realistic engine-out gas compositions were used. The hydrogen feed over the LNR catalyst samples was determined via data achieved by autothermal reforming experiments over a rhodium based catalyst, using real diesel as feedstock. The LNR catalyst samples generally show an enhanced NOx reduction when hydrogen is added to the gas feed. In particular, a 2 wt% silver-alumina sample with the addition of minute amounts of platinum, shows a high increase in NOx reduction when hydrogen is added to the feed. The addition of CO, a potential poison in the reaction and a by-product from the reforming, did not show any significant effect on the LNR catalyst performance at the conditions used. This is beneficial, since it renders a CO clean-up step in the reformer system unneeded. Ammonia formation is discussed in terms of a possible dual-SCR system. Finally, the fuel penalty for hydrogen production and hydrocarbon addition is taken into consideration. It is found that an addition of 1000 ppm H-2 leads to unacceptable fuel penalties. (C) 2011 Elsevier B.V. All rights reserved.
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| 10. |
- Lindgren, Mikaela, 1987, et al.
(författare)
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Confinement dependence of electro-catalysts for hydrogen evolution from water splitting
- 2014
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Ingår i: Beilstein Journal of Nanotechnology. - : Beilstein Institut. - 2190-4286. ; 5:1, s. 195-201
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Tidskriftsartikel (refereegranskat)abstract
- Density functional theory is utilized to articulate a particular generic deconstruction of the electrode/electro-catalyst assembly for the cathode process during water splitting. A computational model was designed to determine how alloying elements control the fraction of H2 released during zirconium oxidation by water relative to the amount of hydrogen picked up by the corroding alloy. This model is utilized to determine the efficiencies of transition metals decorated with hydroxide interfaces in facilitating the electro-catalytic hydrogen evolution reaction. A computational strategy is developed to select an electro-catalyst for hydrogen evolution (HE), where the choice of a transition metal catalyst is guided by the confining environment. The latter may be recast into a nominal pressure experienced by the evolving H2 molecule. We arrived at a novel perspective on the uniqueness of oxide supported atomic Pt as a HE catalyst under ambient conditions.
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