liu.seSearch for publications in DiVA
Change search
Refine search result
12 1 - 50 of 92
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Oldest first
  • Newest first
Select all
  • 1.
    Renbjörk, Eva
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    ATEX classification for construction of bio-fuel factory2007Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Detta examensprojekt är utfört på Ageratec AB som ligger strax utanför Norrköping. Syftet med hela examensprojektet är att göra layoutritningar som används vid ATEX-klassning för byggnationer av biobränslefabriker, som sedan skall ut till beställaren/kunden.

    Min huvuduppgift var att rita en layoutritning för en speciell modell av biobränslefabrik - processor P1000. Detta från uppmätning av processor P1000 till färdig layoutritning i 3D uppritad i AutoCAD, med klassningsplan över farliga ställen och zoner i fabriken. Tanken var att om tiden medgav skulle även ritningar tas fram för de resterande modeller av biobränslefabriker, vilket inte blev fallet. Ageratecs kunder måste nämligen ta hänsyn och följa ATEX-direktiv för arbete i explosionsfarlig miljö som gäller för att driva en biobränslefabrik.

    Vad ATEX-klassning innebär, hur en biobränslefabrik byggs upp och fungerar från början till färdig framställning av biobränsle samt en översikt över de olika typer av biobränslen som finns, tas upp i denna rapport.

    Ageratec startade år 2004 av Gert och David Frykerås. Det är ett familjeföretag med en omsättning på 30 miljoner per år och 32 anställda år 2007. Ageratec tillverkar och säljer helautomatiska processorer över hela världen i olika storlekar som hanterar en volym mellan 1000-288 000 liter biodiesel per dygn. Biobränslefabrikerna är helautomatiskt styrda med hjälp av ett PLC-system från Mitsubishi Electric.

    Processorerna är framtagna för framställning av biobränsle av vegetabiliska oljor, där anläggningen renar oljan och tillsätter metanol eller etanol. Produkten som kommer ut ur anläggningen är så rent och lättflytande att det kan användas som bränsle till dieselmotorer som det är eller blandas med vanlig diesel.

    Med hjälp av utrustning från Ageratec så är det nu möjligt för rapsodlare att även bli lokala drivmedelsproducenter och förvandla den odlade rapsen till biodiesel. Det enda som krävs är en processor från Ageratec samt tillgång till någon typ av fettsyra. Tider och sekvenser sköts automatiskt av PLC-systemet vilket gör att kunden inte behöver tänka på sådant.

    Biodiesel/RME (RapsMetylEster) är ett miljöbränsle som bildar koldioxid men skillnaden är att den mängd koldioxid som bildas av biobränslet är samma mängd som växterna behöver för sin tillväxt. Biodiesel släpper ut 60-80 procent mindre utsläpp av växthusgasen koldioxid jämfört med vanlig dieselolja. Koldioxidhalten ökar alltså inte vid förbränning av biobränsle. Det enda som bidrar till växthuseffekten är koldioxid, därför måste vi vara noga med att inte odla mer än vad vi behöver.

    Den svenska regeringens mål är att 5,75 procent av transportbränslet år 2010 ska utgöras av förnyelsebara drivmedel. Den svenska rapsarealen har ökat med över 70 procent, till 95 000 hektar under de senaste åren. De flesta dieselmotorer behöver inte anpassas på något sätt för att köra på biodiesel.

  • 2.
    Mandari, Zamda
    Linköping University, The Tema Institute, Department of Water and Environmental Studies.
    Perception and realities of biofuels investment in rural livelihood: the case of Kisarawe district,Tanzania2010Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Increase demand for biofuel in the world as the means to mitigate global climate change, energy option and reduced fule import expenses have attracted many companies to acquire land in developing countries like Tanzania. To invest on biofuel in Africa is believed to be a means for generating incomes from expert, to employ rural people, enhance infrastructure development.However, in Africa biofuels policy is still weak.

    This study mainly focuses on people`s expectation during and after the investment.Issue of compensation procedure and promises seems to be a big problem; something brought tension of being cheated among local communities. Futhermore, community involvement and integration of jatropha with smallholder´s agriculture is also low.

  • 3.
    Hjersing, Charlotte
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Hydrogen production in Escherichia coli: Genetic engineering of the formate hydrogenlyase complex2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Biofuels that are renewable and environmentally benign constitute an important area of research, as the supply of fossil fuels decreases and the amount of green house gases in the atmosphere increases. Biohydrogen is not as well explored as other biofuels, but its properties render it a promising complement, as it is clean and can be used directly in fuel cells to generate electricity, the only waste products being water and heat. Hydrogenproducing microorganisms have the potential to be used to recycle industrial waste, such as carbohydrates from food manufacturing. Hence the cost of waste disposal could be reduced whilst biofuel is being produced through microbial processes.

    Escherichia coli is a well-known microorganism that produces hydrogen under fermentative conditions, through the conversion of formate to hydrogen gas and carbon dioxide, via an enzyme complex called formate hydrogenlyase (FHL). The complex is anchored to the inner cell membrane and consists of seven subunits: a formate dehydrogenase, a [Ni-Fe] hydrogenase, three electron carrier proteins, which together make up a large ‘hydrophilic domain’, and two integral membrane proteins (the ‘membrane domain’).

    Even though the entire bacterial genome is known, the FHL complex remains little understood and has proven difficult to isolate and characterise. During this project, a genetically modified strain producing only the hydrophilic domain of FHL was constructed, and the resultant sub-complex was purified. It was hoped that, if a stable and homogenous core complex could be isolated, it might be subjected to further analysis, such as elucidating the subunit stoichiometry and solving the structure.

    Furthermore, FHL is notoriously oxygen labile, which hampers its study and technological development. However, oxygen tolerance is a natural feature found in some other [Ni-Fe] hydrogenases, and recent research shows that this property is likely dependent on the presence of extra cysteine residues near an important metal cluster in the enzyme. These cysteines are not present in FHL and a complex that could be active in both aerobic and anaerobic conditions may be a useful tool in optimising microbial biohydrogen processes. Thus, three strains that each expressed a modified FHL variant carrying single Cysteine-for-Glycine substitutions were constructed. The modified FHL complexes proved to remain active in vivo, and can serve as the basis of genetically engineering oxygen tolerance into this important enzyme.

  • 4.
    Sasu-Boakye, Yaw
    Linköping University, Department of Management and Engineering, Energy Systems.
    MIND - Modelling in Industry for Increased Energy Efficiency and Reduced Greenhouse Gas Emissions2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In industry, energy efficiency reduces system cost and emissions to the environment. Energy audits are carried out in industry to identify measures that would increase energy efficiency. However, the usual case is that low-cost measures are implemented while capital intensive measures receive less attention possibly due to, example, inadequate information available to study risks involved.

    Decisions support tools have been identified as a means of supporting complex production related investment decision. The aim of this paper is to investigate profitability and potential global CO2 emission reduction of energy conversion investments in a small energy intensive industry by using an optimisation method as a decision support tool.

    The investments are evaluated using consistent future energy market scenarios with interdependent parameters. An optimisation model is developed with reMIND optimisation tool which is used to optimise the system cost of each scenario. The reduction in system cost and global CO2 emissions of the new investments and results from sensitivity analysis are evaluated to determine the optimal investment solution.

    In the report, it is established that optimisation methods provide a structured means of studying the risk involved in capital intensive investments. The optimisation results show that investment in a small-scale steam turbine combined heat and power production is a profitable and robust investment. The net reduction of global CO2 emission is substantial compared with the reference system. Furthermore, it is shown that biofuel policies alone may not make cost intensive biofuel investments attractive, further reduction in investment cost is required.

    The energy savings and global CO2 emission reductions achieved in this study can play an important role in achieving the aims of the European Union to reduce greenhouse gas emissions by 20% and save 20 % of energy by the year 2020.

  • 5.
    Elvemo, Kristian
    Linköping University, Department of Management and Engineering, Energy Systems.
    Kapacitetsanalys av CFB-pannan vid SCA Packaging Munksund AB2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The combined heat and power plant at SCA Packaging Munksund AB is a collaboration between SCA and Vattenfall and it consists of a steam boiler with a circulating fluidized bed which was taken in to service in 2001. Today the company wants to make an evaluation about if there is any changes in the CFPboilers performance since the start, they would also like an evaluation about the maximum capacity. The examination work has then been about executing a performance test and a maximum capacity test. The work has also included the construction of an algorithm that would fictively calculate the content of moisture for the in fed biofuel through the fluegas parameters.

    The CFB-boiler is dimensioned to have a thermal effect of 98 MW, with the quality of the biofuel having a content of moisture at 55 % and the heating value of 7,3 MJ/kg. At this operation point the boiler constructor guarantees an efficiency of 90,57 %. Evaluations made in 2002 concluded an efficiency at 91,1 %. The results from this report showed an efficiency at 92,07 %, one should then note that the biofuel quality then had a content of moisture at 50,05 % and a heating value at 8,48 MJ/kg.

    Future increases in the mills production will mean that they also need to increase the steam production as well. From earlier experiences with the boilers capacity, operators have countered problems with the air/fluegas-system at high loads. The primary result from the maximum capacity test is that the quality of the biofuel sets the limit for how well the boiler can perform. The secondary results indicate that the motor for the fluegasfan and that the bedmaterialreentrysystem are the narrow sections. For the test the contest of moisture was 45 % and the produced steam reached 146 ton/h. Something else that surfaced during the report was that the motor for the secondary air fan was not running at the boiler manufacturer dimensioned speed at 1765 rpm, the actual settings had a maximum synchronous speed at 1500 rpm.

    To investigate how much production capacity that is tied up in the narrow sections is extremely difficult to answer, the timeframe for the report limited the digging for an answer for this question. Instead a theoretical analysis was made on the maximum capacity from a perspective of different contests of moisture for the biofuel, watch Figur 33 and Figur 34 on page 78. These figures cast a light on the importance on the quality of the biofuel, so that the boiler has the ability to deliver high loads. Handling of the biofuel to minimize the loss of quality is something that can be affected with relatively simple methods, the recommendation is that a project group is started that looks over the handling of the biofuel to minimize the quality losses during short time storage.

  • 6.
    Carlsson, Annelie
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering.
    Taking external effects into consideration - the bompetitiveness of biofuel2001In: 1st World Conference and Exhibition on Biomass for Energy and Industy,2000, 2001Conference paper (Other academic)
    Abstract [en]

       

  • 7.
    Vega Norell, Pia Carola
    Linköping University, The Tema Institute, Department of Water and Environmental Studies.
    Verktyg för uppskattning av bioenergipotential i kommuner i mellersta och södra Sverige2009Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis is made by commission of Östergötlands County Administrative Board and the Department for Techniques and Environment at the University of Linköping with the purpose of creating a tool which shows the possibilities for the annual bioenergy production in municipalities located in the south and middle of Sweden. This is intended to contribute to the municipal planning and efficiency development of the environmental work within the energy sector. The tool consists of a handbook and a calculation programme. The first one contains information about surveyed biofuel resources which are organized in three categories; field biofuels; forest biofuels and waste fuels and rest products. For each biofuel resource is there information about factors that might  affect the available quantity biofuels for energy production; General information about these resources as sources of energy; Data that has to be fed into the calculation programme; Information about and ideas for data sources

    The handbook is mainly a foundation preliminary to use of the calculation programme and the assessment of its results.  The calculation programme is an easy-to-use Excel document which transforms data into megawatt per hour (MWh).  The calculation programme is partly based on the average amounts (ton/ha) of vintages in Östergötland 2004-2007.  The purpose has been to have a representative region to relate and compare the results with. The results are to be considered rather as guidance than as absolute numbers.

    The survey on biofuels and the information about these has been performed on the basis of subject relevant internet homepages such as environmental portals, public authorities and universities as well as conversations with actors within the environmental and energy sector.

    As next step has the calculation programme been validated before being tested by Norrköpings environmental strategist Enver Memvic who commented the legibility of the handbook and the practical usage of the calculation programme. For this, he typed in rough numbers.  Moreover, an article about tools for environmental decision making has been read as well as three similar calculation tools have been identified. These commentaries and comparisons have been used as basis for the discussion and final reflection. It has been concluded that the created tool can contribute to the municipal planning and efficiency development of the environmental work within the energy sector as long as the mentioned limitations are considered. Conclusions:

    - The created tool is a supportive part of the decision making process within the energy sector. Due to its understandable content, it is considered to increase the possibilities of participation in decision making.

    - The handbook is an informative foundation with an understandable content which simplifies the usage of the easy-to-use calculation programme. On the other side might the handbook's broad extent hinder a more detailed study of each biofuel. The tool is mainly intended to be used by people who deal with the environmental problematic and who are capable of finding ways to take the best advantage from the calculation results.

    - A tool such as this one would be more effective if it was created for the municipalities of each county. A calculation programme with regional statistics as basis for calculations would contribute with more objective results. These results would still be as guidance. The municipalities would still be responsible for eventually developing the collection of data/ database system.

    -  Waste- and rest-products are not yet considered suitable to be included in such a tool due to the big range of involved actors, waste categories, waste treatments, end-uses that there is a lack of sufficient data for. Such a tool is most suitable for field and forest biofuels resources.

    - The used method for creating this tool can be used again as a pattern for developing the efficiency of it or creating a similar one.

  • 8.
    Bjurman, Therese
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Department of Management and Engineering.
    Waste from glued wood - A base for new products and/or bio-fuel?2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

     

    The Swedwood Company is a supplier to IKEA of wood furniture. They have grown larger concurrently with IKEA and at present they have 47 production units spread over twelve countries of which most are located in Eastern Europe.

    One of the factories is Zbaszynek which is located in Poland. They manufacture so called board-on-frame furniture. A board-on-frame is basically made out of particle board frames which are filled with special design paper that enfolds air. The frames are then covered with their skin; thinner particle boards, so called High Density Fibre (HDF) boards, and then edge banded with plastic stripes and painted and lacquered into desired design.

    This production generates not only furniture, last financial year Zbaszynek generated about 61 000 tons wood waste too. It can be compared to their total production of furniture which reached 439 000 tons during the same period of time. This generation of wood waste has caused a problem for Swedwood in general. A project called IKEA Goes Renewable (IGR) has started within IKEA with the aim to reduce the electric- and heat energy consumption and increase the use of renewable energy sources. But to be able to reduce the heat energy at a board-on-frame factory, such as Zbaszynek, there has to be an economic incentive to do so. But the wood waste is contaminated in comparison with waste from pure wood (free from adhesives, plastics etc.) so purchasers have been hard to find. And since the wood waste is used to generate the heat at the factories, the economic value has become relative low. Zbaszynek earn 1.4 €/MWh for their wood waste at present (energy value of 5.1 MWh/ton), while for example recycled contaminated wood chippings (RT-chippings) are worth about 7.3 €/MWh in Sweden (energy value of 4.4-5.1 MWh/ton). RT-chippings in Sweden are even allowed to contain more contaminations to receive that price, as long as it is not pressure creosoted. 1.4 €/MWh can also be compared to the economic value of coal which is about 13.7 €/MWh, and for district heating to households in Sweden was the average price about 68 €/MWh during 2007 (Energimarknadsinspektionen, 2007).Therefore, the main task of this thesis has been to investigate if there are any possible solutions to increase the economic value of the wood waste in Zbaszynek. There are more board-on-frame factories within Swedwood with the same problem, but Zbaszynek has been the pilot factory during this research.

    The first thing which should be considered in Zbaszynek is to keep the amount of waste as low as possible. The main task should be to reduce the amounts of wood waste; in the end it is a furniture factory and not a waste producer, which should be concerned before taking any further action. It is assumed though that this has already been thought through in Zbaszynek and further investigation of the waste has taken place.The wood waste has been sent to the Eurofins laboratory in Sweden for an analysis and the test results were then compared to wood waste of pure wood. The comparison indicates the nitrogen content being the main difference between Zbaszynek's wood waste and pure wood. Nitrogen compounds, often referred to as NOx can cause severe damage to the environment and foremost lead to increased eutrophication (= Eutrofizacja (Polish) / Övergödning (Swedish)) when it is emitted to the air. Apart from the nitrogen contamination, other significant differences have not been found. The energy content of the wood waste has even revealed it would suit well as bio-fuel, on the condition that proper equipment to reduce the NOx emissions is present. It has been calculated that the energy content, of the generated wood waste in Zbaszynek during Financial Year 2008, reached 310 GWh. Which can be compared to the electricity consumption of 78 GWh as was bought during the same time of period.

    Four main possibilities have been investigated in this report and they are:

    • - Selling the waste to cement producers as alternative fuel

    • - Make new products and use for furniture production again

    • - Make briquettes or pellets and sell as fuel

    • - Start up a Combined Heat and Power plant and produce electricity

    All these alternatives have their advantages and disadvantages but they all seem to be realistic solutions, on a few conditions.

  • 9.
    Åkesson, Ola
    Linköping University, Department of Electrical Engineering.
    Studie samt reglering av luft- och massflöde för en barkpanna2007Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    This report treats two assignments that concerns the biofuel furnace at Billerud Skärblacka AB and how these assignments were solved. The assignments were: reducing the number of CO-spikes and tuning the overfire air control loop. To reduce the number of CO-spikes the possibility that skewness in mass distribution affects the number of CO-spikes were study. The skewnwss of mass distribution was controled and adjusted with two experiments. The conclusion that was made is that the skewness of mass distribution were not sufficient enough to affect the number of CO-spikes. Most likely because there are other factor that affects the number of CO-spikes more than the skewness of mass distribution.

    The objective with tuning the overfire air control loop was to find a faster and better interplayed control loop. To solve the assignment the first thought was to make a model of the furnace. But this idea was too much work for a single master thesis. Therefore a Simulink-model and a control strategy were produced instead. During the work with tuning the overfire air control loop the changes were issued from the control strategy and the Simulink-model were used for the tuning of the air valves. The result from tuning the overfire air control loop were faster regulators and a better tracking of the reference value for the secondary and tertiary air valve along with a reduced levels of carbon monoxide.

  • 10.
    Luwa, Kilama Justine
    Linköping University, The Tema Institute, Department of Water and Environmental Studies.
    Power and Development: Controversies over the Bujagali Hydropower Porject Along the Nile River in Uganda2007Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    Mega projects are in most cases considered as the necessary evil of development. Before their benefits can be reaped, a lot of sacrifices and tough choices have to be made. The fear and uncertainties surrounding such projects range from the impacts on the local people, on the environment, the costs of investment, and to, if the project will deliver the promised benefits. Because of these fears and uncertainties, it is not unusual that most if not all such projects meet a lot of critics and resistance before their success or failures are witnessed. Today, it is more of a requirement than a belief (although without a guarantee) that stakeholders’ involvement and their active participation in all decision-making process concerning a project is the surest way of minimizing conflicts and ensuring justice. The Bujagali hydropower project being an example of such projects and without immunity to the problems faced by other mega project around the world has been a case study for this thesis. This study has therefore focused on institutional arrangements that governed the management and utilization of water resources in connection to hydropower development along the Nile River in Uganda, the procedures and stages of the negotiations for hydropower infrastructure development in Uganda, identified the major stakeholders that take part in such negotiations and looked in detail for what their issues and interests are. It has also examined the attitudes and opinions of stakeholders on the potential and benefits of hydropower against (solar, bio-fuel and geothermal) energy sources in the context of Uganda, taking into consideration the need for socio-economic development, preservation of culture and environmental protection. Finally, it has analyzed the conflicts/controversies that have arisen in the Bujagali hydropower project.

  • 11.
    Gerebring, Linnéa
    Linköping University, Department of Physics, Chemistry and Biology.
    Yeast Saccharomyces cerevisiae strain isolated from lager beer shows tolerance to isobutanol.2016Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The development of biofuels has received much attention due to the global warming and limited resources associated with fossil fuels. Butanol has been identified as a potential option due to its advantages over ethanol, for example higher energy density, compatibility with current infrastructure and its possibility to be blended with gasoline at any ratio. Yeast Saccharomyces cerevisiae can be used as a producer of butanol. However, butanol toxicity to the host limits the yield produced. In this study, four strains of yeast isolated from the habitats of lager beer, ale, wine and baker ́s yeast were grown in YPD media containing isobutanol concentrations of 1.5 %, 2 %, 3 % and 4 %. Growth was measured to determine the most tolerant strain. Gene expression for the genes RPN4, RTG1 and ILV2 was also measured, to determine its involvement in butanol stress. The genes have in previous studies seen to be involved in butanol tolerance or production, and the hypothesis was that they all should be upregulated in response to butanol exposure. It was found that the yeast strain isolated from lager beer was most tolerant to isobutanol concentrations of 2 % and 3 %. It was also found that the gene RPN4 was upregulated in response to isobutanol stress. There was no upregulation of RTG1 or ILV2, which was unexpected. The yeast strain isolated from lager beer and the gene RPN4 is proposed to be investigated further, to be able to engineer a suitable producer of the biofuel butanol. 

  • 12.
    Hansson, Cecilia
    Linköping University, Department of Physics, Chemistry and Biology.
    Identification of a butanol tolerant Saccharomyces cerevisiae strain and of a gene associated with enhanced butanol tolerance.2016Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The most widely used biofuel on the market today is ethanol derived from food crops, such as maize and sugarcane. Ethanol is renewable and environmental friendly but the low energy density makes it unable to compete with fossil fuels. Enlarged focus on replacing fossil fuels with biofuels from renewable biomass have identified isobutanol and 1-butanol as future biofuels, possessing similar capabilities as gasoline e.g. high octane number and energy density. The yeast Saccharomyces cerevisiae can produce butanol through fermentation of carbohydrates but butanol concentrations over 2% is toxic to most strains. To reach the commercial requirements for economic and efficient isobutanol production using S. cerevisiae, higher butanol tolerance is crucial.

    The butanol tolerance of isolated strains of S. cerevisiae from different habitats were examined using spot plating and growth measurements. The results showed variance in butanol tolerance between strains, where the most tolerant strains were able to grow in isobutanol concentration up to 3 %. The expression of genes associated with increased butanol tolerance was investigated by Quantitative Real-time PCR. Data showed an upregulation of RPN4 in strains subjected to butanol induced stress. The study aims to identify butanol tolerant strains that can be engineered for efficient butanol production for sustainable biofuel production.

  • 13.
    Westberg, Emilie
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Qualitative and Quantitative Analysis of Biodiesel Deposits Formed on a Hot Metal Surface2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis aims to investigate the formation of deposits from thermally degraded biodiesel on a hot metal surface under the influence of sodium or copper contaminations. Biodiesel or Fatty Acid Methyl Esters (FAMEs) is a widely utilized biofuel with the potential to replace fossil fuels, however, issues regarding the thermal and oxidative stability prevent the progress of biodiesel for utilization as vehicle fuel. The thermal degradation of biodiesel causes formation of deposits often occurring in the fuel injectors, which could result in reduced engine efficiency, increased emissions and engine wear. However, still have no standard method for evaluation of a fuels’ tendency to form deposits been developed. In this study biodiesel deposits have been formed on aluminum test tubes utilizing a Hot Liquid Process Simulator (HLPS), an instrument based on the principle of the Jet Fuel Thermal Oxidation Tester (JFTOT). Quantitative and qualitative analyses have been made utilizing an array of techniques including Scanning Electron Microscopy (SEM), Gas Chromatography Mass Spectrometry (GCMS) and Attenuated Total Reflectance Fourier Transform Infrared Spectrometry (ATR-FTIR). A multi-factorial trial investigating the effects of sodium hydroxide and copper contaminations at trace levels and the impact of a paraffin inhibitor copolymer additive on three different FAME products, two derived from rapeseed oil and one from waste cooking oil as well as a biodiesel blend with mineral diesel, was conducted.The results exhibited that FAMEs are the major precursor to deposit formation in diesel fuel. The SEM analyses exploited the nature of FAME deposits forming porous structures on hot metal surfaces. Sodium hydroxide proved to participate in the deposit formation by forming carboxylic salts. However, the copper contamination exhibited no enhancing effect on the deposits, possibly due to interference of the blank oil in which copper was received. The paraffin inhibitor functioning as a crystal modifier had significant reducing effect on the deposit formation for all biodiesel samples except for the FAME product derived from waste cooking oil. Further studies are needed in order to investigate the influence of glycerin and water residues to the biodiesel deposit formation. Mechanisms involving oxidative or thermal peroxide formation, polymerization and disintegration have been suggested as degradation pathways for biodiesel. The involvement of oxidation intermediates, peroxides, was confirmed by the experiments performed in this thesis. However, the mechanisms of biodiesel deposit formation are complex and hard to study as the deposits are seemingly insoluble. Nevertheless, ATR-FTIR in combination with JFTOT-processing has potential as standard method for evaluation of deposit forming tendencies of biodiesel.

  • 14.
    Wetterlund, Elisabeth
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Difs, Kristina
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy policies affecting biomass gasification applications in district heating systems2009In: Proceedings of the First International Conference on Applied Energy, 5-7 January 2009, Hong Kong, 2009, 1502-1512 p.Conference paper (Refereed)
    Abstract [en]

    Biomass gasification is considered a key technology in reaching targets for renewable energy and CO2 emissions reduction. This study evaluates policy instruments affecting the profitability of biomass gasification applications integrated in a Swedish district heating (DH) system for the medium-term future (around year 2025). Two gasification applications are included: co-production of SNG (synthetic natural gas) for use as transportation fuel and DH heat in a biorefinery, and BIGCC CHP (biomass integrated gasification combined cycle, combined heat and power). Using an optimisation model the level of policy support necessary to make biofuel production competitive to electricity generation, and the level of tradable green electricity certificates necessary to make gasification based electricity generation competitive to conventional steam cycle technology, are identified. The results show that in order for investment in SNG production to be competitive to investment in electricity production in the DH system, support policies promoting biofuels in the range of 16-22 EUR/MWh are needed. For investment in BIGCC CHP to be competitive to investment in conventional steam cycle CHP tradable green electricity certificates in the range of 4-15 EUR/MWh are necessary. The necessary policy support levels are very sensitive to variations in investment costs. It is concluded that the large capital commitment and strong dependency on policy tools makes it necessary that DH suppliers believe in the long-sightedness of future policy tools, in order for investments in large-scale biomass gasification in DH systems to be realised.

  • 15.
    Henning, Dag
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Danestig, Maria
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Local development possibilities for sustainable energy supply and use in Sweden2007In: In B. Frostell, Å. Danielsson, L. Hagberg, B.-O. Linnér, E. Lisberg Jensen (eds., Science for Sustainable Development - The Social Challenge with emphasis on conditions for change, Proceedings from the 2nd VHU Conference, Linköping 6-7 September, Uppsala: VHU, 2007Conference paper (Other academic)
    Abstract [en]

    Large structural changes are necessary to reduce the resource use in industrialised countries to a sustainable level. Modifications of municipalities’ normal operations can contribute to a more ecologically, economically and socially sustainable society through, for example, promotion of measures concerning energy conservation and renewable energy supply. In the Swedish Energy Agency’s Sustainable municipality programme, it is developed how spatial plans of ground use and building development can promote local renewable energy sources and efficient energy utilisation. Energy issues can be integrated in spatial planning through scenarios of future energy supply and use, which are discussed by local stakeholders. It can be shown how wall insulation, solar heating and heat recovery can reduce primary energy demand and that switching from electricity to biofuel can reduce CO2 emissions. The indicator heat load density depends on building structure and shows, for instance, preconditions for district heating, which often is a favourable heating option. If the local energy utility is involved in spatial planning, it may facilitate the introduction of temporary solutions, such as pellets boilers, to make more customers chose district heating in areas where the network is delayed. District heating systems enable efficient electricity generation in combined heat and power (CHP) plants, which can be elucidated by an optimisation model that considers economy and environment. Strategic spatial planning can promote establishment and expansion of district heating networks.

  • 16.
    Krook, Joakim
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Mårtensson, Anders
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Metal contamination in recovered waste wood used as energy source in Sweden.2004In: Resources, Conservation and Recycling, ISSN 0921-3449, Vol. 41, no 1, 1-14 p.Article in journal (Refereed)
    Abstract [en]

    Large amounts of recovered waste wood (RWW) originating from construction and demolition activities (C&DWW) and industrial activities (IWW) are annually generated in Sweden. RWW is also imported for use as an energy source at biofuel boilers. Increased use of biomass is one strategy to decrease environmental impact, in general, and the emissions of green house gases, in particular. This study addresses the environmental and resource implications of metal occurrence in RWW that is used as an energy source at biofuel boilers. RWW contains elevated concentrations of arsenic, chromium, copper, zinc, mercury, nickel, lead and possibly cadmium. The metal composition of Swedish and imported RWW differs in that Swedish RWW contains higher concentrations of arsenic, chromium, zinc, nickel and copper, while imported RWW contains higher concentrations of lead, mercury and cadmium. Ashes from combustion of RWW are nowadays generally disposed in landfills due to their elevated metal concentrations. This practice makes it impossible to use these ashes as filler material thereby replacing extraction of raw materials and decreasing the need for landfill space. Furthermore, landfilling leads to accumulation of hazardous heavy metals that poses a future environmental and health problem. If RWW from construction and demolition should contribute optimally to a sustainable energy system, cleaner waste wood flows are a prerequisite. The elementary measure is to track potential pollution sources in this waste stream and find out which are significant. Furthermore, since most of the RWW is untreated and unpolluted wood, there is a great environmental potential to separate this flow through the waste management system. Such an approach might lead to decreased environmental pollution of heavy metals and an improved resource management.

  • 17.
    Henning, Dag
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Trygg, Louise
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Gebremedhin, Alemayehu
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Enhanced biofuel utilisation in Swedish industries, buildings and district heating2006In: the World Bioenergy 2006 Conference and exhibition on Biomass for Energy, Jönköping, Sweden, 30 may – 1 June, 2006, 198-203 p.Conference paper (Refereed)
  • 18.
    Klugman, Sofia
    et al.
    University of Gävle.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    A Swedish integrated pulp and paper mill - Energy optimisation and local heat cooperation2009In: Energy Policy, ISSN 0301-4215, Vol. 37, no 7, 2514-2524 p.Article in journal (Refereed)
    Abstract [en]

    Heat cooperation between industries and district heating companies is often economically and environmentally beneficial. In this paper, energy cooperation between an integrated Swedish pulp and paper mill and two nearby energy companies was analysed through economic optimisations. The synergies of cooperation were evaluated through optimisations with different system perspectives. Three changes of the energy system and combinations of them were analysed. The changes were process integration, extending biofuel boiler and turbine capacity and connection to a local heat market. The results show that the single most promising system change is extending biofuel and turbine capacity. Process integration within the pulp and paper mill would take place through installing evaporation units that yield less excess heat but must in this particular case be combined with extended biofuel combustion capacity in order to be beneficial. Connecting to the local heat market would be beneficial for the pulp and paper mill, while the studied energy company needs to extend its biofuel capacity in order to benefit from the local heat market. Furthermore, the potential of reducing CO2 emissions through the energy cooperation is shown to be extensive; particularly if biofuel and turbine capacity is increased.

  • 19.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Wolf, Anna
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Using an optimisation model to evaluate industrial symbiosis in the forest industry2008In: Journal of Cleaner Production, ISSN 0959-6526, Vol. 16, no 14, 1536-1544 p.Article in journal (Refereed)
    Abstract [en]

    In this work, a model comprising a pulp mill, a sawmill, a district heating network and a biofuel upgrading plant is used to demonstrate how the MIND method, an optimization method based on mixed integer linear programming, can be used to evaluate industrial symbiosis in the forest industry. Using this method, both energy and material flows on both the supply and the demand side can be studied simultaneously. The method can be used to find improvements in the structure of the modelled system, to find the optimal operational strategy of a given system, and to evaluate and compare different systems. The total system costs for stand-alone cases and integrated industrial symbiosis system configuration are compared, generating results that can be used as decision support when planning industrial symbiosis initiatives in the forest industry. The results of this study showed that there are financial benefits to industrial symbiosis compared to the same system operated in stand-alone mode, and that the industrial symbiosis configuration generates a more stable system. However, it is difficult to generalize the results from a case study, and the main conclusion drawn is that it is possible to show that industrial symbiosis has economical benefits, although the magnitude of these benefits needs to be evaluated from case to case.

  • 20.
    Wolf, Anna
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Energy Systems.
    Vidlund, Anna
    Department of Chemical Engineering and Technology, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Andersson, Eva
    Department of Energy and Environment, Chalmers, Göteborg, Sweden.
    Energy efficient pellet production in the forest industry: A study of obstacles and success factors2005In: Biomass and Bioenergy, ISSN 0961-9534, Vol. 30, no 1, 38-45 p.Article in journal (Refereed)
    Abstract [en]

    With an expanding market for upgraded biofuel in many countries, it is important to develop efficient production methods for upgrading wet biomass. The possibilities for heat recovery can be improved if the upgrading process is integrated with other energy-intensive processes, as for example a pulp mill or a sawmill, in a biofuel combine. This work evaluates obstacles and success factors for forming such biofuel combines with the forest industry. Case studies and calculations on theoretical cases have been used together with literature references to evaluate how a biofuel combine can be realised and to compile obstacles and success factors for a combine.

    It could be seen from the case studies that an excess of by-products and waste heat, together with an existing need for investments are important driving forces for the formation of biofuel combines in the forest industry. The market was also identified as an important factor, which can be both an obstacle and a success factor depending on the situation. It was concluded that the existence of a small-scale pellet market near the plant is important for economic feasibility when sawdust is used as raw material. The conditions for the biofuel combine are different depending on the form of ownership. When a pulp mill or sawmill owns the pellet factory, it was concluded that minimising the risk by using well-known technologies can be an important factor for the realisation of the combine.

  • 21.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Ivner, Jenny
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Svensson, Niclas
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Classification of Industrial Symbiosis Synergies:: Application in the Biofuels Industry2009In: Industrial Symbiosis and Eco-Industrial Parks, Aalborg: GIN 2009 , 2009, 2394- p.Conference paper (Other academic)
    Abstract [en]

    In the production of biofuels for transportation, i.e. biodiesel, bioethanol and biogas, a vast range of unique resource flows, surpluses and by-products exist in each respective process. The current research project aims to find synergies, demands and surplus material and energy flows which will thereafter be applied to the biofuel industry and external industries in a collaborative effort to increase energy efficiencies and environmental performance through the use of synergies and industrial symbiosis. This is being conducted in order to determine conditions for implementation, why some processes and synergies exist, how the processes can be made better and to identify new material flows between industries.

    During an investigation of synergies apparent in the regional biofuel industries, many synergies were discussed during a brainstorming session with industrial actors and researchers. These synergies were recorded and classified in terms of their interaction with other biofuel and external industries. Using the theories of industrial symbiosis, a classification method was developed based upon these interactions as well as the origin and destination of their resources. Previous terms from the theories of synergies research were used as background material. Thereafter symbols and classifications were based on the interactions of the synergy, i.e. between biofuel industries and external synergies. Furthermore the origins/destinations were also classified as either a product/process or as a utility but with expanded and refined boundaries.

    Example: 2UP (A synergy of Class 2, i.e. biofuel to external industry synergy, which originates as a utility and is destined as a product/process for the external industry.)

    Thus far the project has produced a classification scheme for biofuel synergy projects and research. Using the classification method, synergies produced at future brainstorming sessions and discussions with industry will alleviate the reproduction, recording and organization of synergies for upcoming interaction with biofuel industries worldwide.

  • 22.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Ivner, Jenny
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Svensson, Niclas
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Biofuel Synergy Development: Classification and Identification of Synergies Using Industrial Symbiosis2009Report (Other academic)
    Abstract [en]

    Many critics argue that biofuel production worldwide account for huge losses in energy and materials. Moreover, a large portion of studies around biofuel production are concentrated on stand-alone plants, particularly ethanol production. However, by including by-products and making use of excess energy and material streams, industrial symbiosis methods can be applied to biofuel industries to improve both environmental and economical performance. The following report outlines an approach to apply industrial symbiosis to several biofuel industry actors through synergy development. Synergies were produced during a brainstorming session in order to bring forward innovative and technically feasible ideas toward partnership. From those synergies developed, the report outlines a method to classify synergies and cooperation between biofuel and external industries in order to ease implementation and understanding of possible symbiosis options for industry and academia.

  • 23.
    Henning, Dag
    et al.
    Optensys Energianalys .
    Gebremedhin, Alemayehu
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Energy Systems.
    Future biofuel utilisation for small-scale heating and large-scale heat, electricity and automotive fuel production2008In: World Bioenergy 2008. Taking you from Know-how to Show-how,2008, 2008Conference paper (Refereed)
    Abstract [en]

         

  • 24.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Mwakaje, Agnes G
    University Dar Es Salaam.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Biofuel development initiatives in Tanzania: development activities, scales of production and conditions for implementation and utilization2009In: JOURNAL OF CLEANER PRODUCTION, ISSN 0959-6526, Vol. 17, no Sp. Iss. SI Suppl. 1, S69-S76 p.Article in journal (Refereed)
    Abstract [en]

    In recent years biofuel activities have increased dramatically in Africa. Simultaneously biofuels have become popular for fuel alternatives and criticism in the media. Nonetheless biofuel initiatives are taking place on different scales. A depiction of several of these activities has been produced through descriptions and categorization based on scale, distribution and implementation. These initiatives exist due to a complex interaction of social and technical factors which have influenced their success for being introduced, and continues to influence the scale on which they exist and what will happen to them in the future. Conditions for implementation are furthermore explored regarding legislation, use of biofuels, environmental sustainability and the production of a new energy system in Tanzania.

  • 25.
    Difs, Kristina
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Trygg, Louise
    Increased industrial district heating use in a CHP system: economic consequences and impact on global CO2 emissions2009In: 5th European Conference on Economics and Management of Energy in Industry, 2009Conference paper (Other academic)
    Abstract [en]

    The use of district heating (DH) in industrial processes is relatively limited compared to other fuels and electricity. Hence, the industrial sector has great potential to convert from electricity and fossil fuels to DH. In addition, DH is mainly used for space heating and hot tap water, which makes the DH demand strongly seasonally dependent. By converting industrial processes like cooling, drying and industrial heating to DH, the heat load curve will be more evenly distributed throughout the year, thus utilizing the DH production resources better. This paper analyses how conversions from electricity or other fuels to district heating (DH) in industrial processes will affect an energy system. The effect of a more evenly distributed heat load profile is analysed with different policy instruments, fuel prices and electricity prices. In this study, three CHP plants acting as base load plants, which utilize different fuels (biofuel, waste and natural gas), are analysed. The result shows that when the use of district heating in industrial processes is increased it will lead to reduced system cost in both the biofueled and waste-incinerated combined heat and power system. Furthermore, when considering European electricity production in coal condensing and natural gas power plants, conversion to DH will also lead to possible reduced global CO2 emissions.

  • 26.
    Djuric Ilic, Danica
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Dotzauer, Erik
    School of Sustainable Development of Society and Technology, Mälardalen University, Västerås, Sweden.
    Trygg, Louise
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    District heating and ethanol production through polygeneration in Stockholm2012In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 91, no 1, 214-221 p.Article in journal (Refereed)
    Abstract [en]

    Ethanol can be produced with little impact on the environment through the use of polygeneration technology. This paper evaluates the potential of integrating a lignocellulosic ethanol plant into a district heating system by case study; the plant has an ethanol capacity of 95 MW with biogas. electricity and heat as by-products. Stockholms district heating system is used as the case study, but the results may be relevant also for other urban areas. The system has been studied using MODEST - an optimisation model framework. The results show that introducing the plant would lead to a significant reduction in the cost of heat production. The income from the biofuels and electricity produced would be about (sic)76 million and (sic)130 million annually, respectively, which is an increase of 70% compared to the income from the electricity produced in the system today. Assuming that the electricity produced will replace marginal electricity on the European electricity market and that the biofuel produced will replace gasoline in the transport sector, the introduction of the polygeneration plant in the district heating system would lead to a reduction of global CO(2) emissions of about 0.7 million tonnes annually.

  • 27.
    Wetterlund, Elisabeth
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Leduc, Sylvain
    International Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, Laxenburg A-2361, Austria.
    Dotzauer, Erik
    Mälardalen University, P.O. Box 883, SE-721 23 Västerås, Sweden.
    Kindermann, Georg
    International Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, Laxenburg A-2361, Austria.
    Optimal localisation of biofuel production on a European scale2012In: Energy, ISSN 0360-5442, Vol. 41, no 1, 462-472 p.Article in journal (Refereed)
    Abstract [en]

    This paper presents the development and use of an optimisation model suitable for analysis of biofuel production scenarios in the EU, with the aim of examining second generation biofuel production. Two policy instruments are considered – targeted biofuel support and a CO2 cost. The results show that over 3% of the total transport fuel demand can be met by second generation biofuels at a cost of approximately 65-73 EUR/MWh. With current energy prices, this demands biofuel support comparable to existing tax exemptions (around 30 EUR/MWh), or a CO2 cost of around 60 EUR/tCO2. Parameters having large effect on biofuel production include feedstock availability, fossil fuel price and capital costs. It is concluded that in order to avoid suboptimal energy systems, heat and electricity applications should also be included when evaluating optimal bioenergy use. It is also concluded that while forceful policies promoting biofuels may lead to a high biofuel share at reasonable costs, this is not a certain path towards maximised CO2 emission mitigation. Policies aiming to promote the use of bioenergy thus need to be carefully designed in order to avoid conflicts between different parts of the EU targets for renewable energy and CO2 emission mitigation.

  • 28.
    Nordén, Björn
    et al.
    he Norwegian Institute for Nature Research, Oslo, Norway and Department of Biology and Environmental Science, University of Gothenburg, Göteborg, Sweden.
    Paltto, Heidi
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology.
    Claesson, Christina
    Department of Biology and Environmental Science, University of Gothenburg, Göteborg, Sweden.
    Götmark, Frank
    Department of Biology and Environmental Science, University of Gothenburg, Göteborg, Sweden.
    Partial cutting can enhance epiphyte conservation in temperate oak-rich forests2012In: Forest Ecology and Management, ISSN 0378-1127, Vol. 270, 35-44 p.Article in journal (Refereed)
    Abstract [en]

    The strongly increasing demand for biofuel from forests poses new challenges for biodiversity conservation. Methods that may combine biofuel production with conservation goals need to be tested for various forest types. One possible conservation-oriented management alternative is partial cutting of closed canopy oak-rich forests (may also be called conservation thinning). Such cutting may counteract succession and restore a semi-open canopy structure, which may favor epiphytes. We evaluated this possibility by surveying the epiphyte community of lichens and bryophytes on large oaks in 24 oak-rich temperate forests in southern Sweden. Treatment plots, and reference plots with no cutting, were surveyed before, and 6 years after cutting. In the treatment plots, about 25% of the basal area was harvested, and mainly small and intermediate sized successional trees were removed. We detected significant positive effects of partial cutting on species density for both lichens and bryophytes. The additional variation in light influx at tree level (after the cutting) could not explain the change in species density. The increase in density of lichen species was highest on oaks with small trunk diameter and on oaks with deep bark crevices. The pooled frequency of species of conservation concern increased after the cutting, but the change in species composition was weak; colonization events occurred over mean minimum distances of 63.5 m to the nearest potential source tree (n = 22 events and 9 species). Overall, we found significantly higher colonization rates, and significantly lower extinction rates per tree for lichens in the treatment plots. We conclude that partial cutting influenced epiphytes of large oaks positively, as was the case for several other organism groups at the same study sites (previous studies). A mild form of biofuel harvesting may represent sustainable resource-use in these forests, compatible with conservation. However, part of the forest should be kept untouched for species vulnerable to changes in microclimatic conditions, and for evaluation of long-term effects.

  • 29.
    Axelsson, Lisa
    et al.
    Chalmers University of Technology, Göteborg, Sweden.
    Franzén, Maria
    Chalmers University of Technology, Göteborg, Sweden.
    Ostwald, Madelene
    Linköping University, Department of Thematic Studies, Centre for Climate Science and Policy Research. Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Chalmers University of Technology, Göteborg, Sweden.
    Berndes, Goran
    Chalmers University of Technology, Göteborg, Sweden.
    Lakshmi, G
    Indian Institute Science, Bangalore, India.
    Ravindranath, N H
    Indian Institute Science, Bangalore, India.
    Jatropha cultivation in southern India: assessing farmers experiences2012In: Biofuels, Bioproducts and Biorefining, ISSN 1932-104X, E-ISSN 1932-1031, Vol. 6, no 3, 246-256 p.Article in journal (Refereed)
    Abstract [en]

    Together with 106 farmers who started growing Jatropha (Jatropha curcas L.) in 20042006, this research sought to increase the knowledge around the real-life experience of Jatropha farming in the southern India states of Tamil Nadu and Andhra Pradesh. Launched as an alternative for diesel in India, Jatropha has been promoted as a non-edible plant that could grow on poor soils, yield oil-rich seeds for production of bio-diesel, and not compete directly with food production. Through interviews with the farmers, information was gathered regarding their socio-economic situation, the implementation and performance of their Jatropha plantations, and their reasons for continuing or discontinuing Jatropha cultivation. Results reveal that 82% of the farmers had substituted former cropland for their Jatropha cultivation. By 2010, 85% (n = 90) of the farmers who cultivated Jatropha in 2004 had stopped. Cultivating the crop did not give the economic returns the farmers anticipated, mainly due to a lack of information about the crop and its maintenance during cultivation and due to water scarcity. A majority of the farmers irrigated and applied fertilizer, and even pesticides. Many problems experienced by the farmers were due to limited knowledge about cultivating Jatropha caused by poor planning and implementation of the national Jatropha program. Extension services, subsidies, and other support were not provided as promised. The farmers who continued cultivation had means of income other than Jatropha and held hopes of a future Jatropha market. The lack of market structures, such as purchase agreements and buyers, as well as a low retail price for the seeds, were frequently stated as barriers to Jatropha cultivation. For Jatropha biodiesel to perform well, efforts are needed to improve yield levels and stability through genetic improvements and drought tolerance, as well as agriculture extension services to support adoption of the crop. Government programs will -probably be more effective if implementing biodiesel production is conjoined with stimulating the demand for Jatropha biodiesel. To avoid food-biofuel competition, additional measures may be needed such as land-use restrictions for Jatropha producers and taxes on biofuels or biofuel feedstocks to improve the competitiveness of the food sector compared to the bioenergy sector.

  • 30.
    ASTON, WJ
    et al.
    CRANFIELD INST TECHNOL,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    BIOSENSORS AND BIOFUEL CELLS1984In: Biotechnology & genetic engineering reviews, ISSN 0264-8725, Vol. 1, 89-120 p.Article, review/survey (Refereed)
    Abstract [en]

    n/a

  • 31.
    Brito, Paula
    et al.
    Cranfield University, Cranfield MK43 0AL, Beds, England.
    P. F. Turner, Anthony
    Cranfield University, UK.
    Mediated Biocatalytic Electrodes and Enzyme Stabilisation for Power Generation2010In: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 22, no 08-jul, 732-743 p.Article, review/survey (Refereed)
    Abstract [en]

    This contribution considers the origins, principles and recent literature published on enzymatic biofuel cells, with a focus on performance and stability. Modified or new biofuel cell components, such as modified electrodes, new enzymes and the use of new mediators to improve power output and stability are reviewed. The development of biofuel cells to date leaves huge potential for further improvement and practical application. Cooperation between different fields of science is essential to realise important potential applications in human health and power generation; future research needs to achieve this are discussed.

  • 32.
    Berglund, Björn
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Ersson, Carolina
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Martin, Michael
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Challenges for developing a system for biogas as vehicle fuel: lessons from Linkoping, Sweden2011Conference paper (Other academic)
    Abstract [en]

    Biofuels are being employed in nearly all the EU member states to fulfill the targets set up by the European Directive 2003/30/EC to have a 5.75% share of renewable energy in their transport sector by 2010. In Sweden ethanol is the leading biofuel, while biogas mainly depend on local initiatives with the city of Linköping as a case in point.

    Our purpose with this article is to analyze the development of biogas in Linköping within a framework of technological transition theory. To this we add a set of concepts from large technical systems-literature to address and re-analyze two earlier studies on the biogas development in Linköping to achieve a deeper understanding of this success story. We argue that the establishment of a development trajectory for biogas depended on the ability of the involved actors to establish and nurture their social network, to create learning processes and stimulate the articulation of expectations and visions. It was also important that these three factors were allowed to influence each other for the system to gain a momentum of its own.

    Furthermore, the biogas development in Linköping is found to be interesting in that the triggers for the development came from a variety of levels and angles. Initially, the rising fuel prices after the oil crises in the 1970’s resulted in an increased interest in renewable fuels in general. Second, an anticipated national pipeline for natural gas planned through Linköping was considered a huge potential for methane exports. A part from these external energy incentives, the local trigger was the bad urban air quality caused by the public transport authority’s bus fleet. The breakthrough came when it was discovered that by-product biogas from the wastewater treatment facility could be used as a fuel for transport.

    When the plans for the national pipeline were rejected, a fruitful co-operation between the municipally owned production facility and the public transport authority was set up to meet the constructed demand from public transport. This cooperative pair-arrangement was the starting point for the biogas niche trajectory as other actors subsequently were enrolled to increase the size and agency of the network.

    Nowadays, biogas and other renewable fuels play a significant role in the supply of transport fuels for Linköping. In 2009, a total of 9.5% of all transport fuels used in Linköping were from renewable sources, i.e. biogas (4.6%), ethanol and biodiesel. This puts the city well ahead of the European target of 5.75% renewable fuels by 2010.

  • 33.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Svensson, Niclas
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Fonseca, Jorge
    Linköping University, Department of Management and Engineering, Environmental Technology and Management.
    Assessing the Environmental Performance of Integrated Ethanol and Biogas Production:: Quantifying Industrial Symbiosis in the Biofuel Industry2011Report (Other academic)
    Abstract [en]

    As the production of biofuels continues to expand worldwide, criticism about many issues, including the energy output versus input and the competition with food, has been raised andthe sustainability of biofuels in recent years has been constantly debated. However, the current biofuel systems may be optimized to increase the energy efficiency and environmentalperformance. By using concepts from industrial symbiosis, the material and energy exchangesmay be optimized to result in these performance improvements. This paper offers aquantification of the environmental performance of industrial symbiosis in the biofuelindustry through integration of biogas and ethanol processes using a life cycle approach.Results show that although increasing integration between the biogas and ethanol plants isassumed to produce environmental benefits, not all impact categories have achieved this andthe results depend upon the allocation methods chosen. Thus the increasing integration alsobrings about increased complexity for the system.

  • 34.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Improving the Environmental Performance of Biofuels with Industrial Symbiosis2011In: Biomass and Bioenergy, ISSN 0961-9534, Vol. 35, no 5, 1747-1755 p.Article in journal (Refereed)
    Abstract [en]

    In the production of biofuels for transport many critics have argued about the poor energyefficiency and environmental performance of the production industries. Optimism is thusset on the production of second generation biofuels, while first generation biofuelscontinue to dominate worldwide. Therefore it is interesting to consider how the environmentalperformance of first generation biofuel industries can be improved. The field ofindustrial symbiosis offers many possibilities for potential improvements in the biofuelindustry and theories from this research field are used in this paper to highlight howenvironmental performance improvements can be accomplished. This comes in the formof by-product synergies and utility synergies which can improve material and energyhandling. Furthermore, the processes and products can gain increased environmentalperformance improvements by the adaption of a renewable energy system which will actas a utility provider for many industries in a symbiotic network. By-products may thereafterbe upcycled through biogas production processes to generate both energy and a biofertilizer. A case study of an actual biofuel industrial symbiosis is also reviewed to providesupport for these theories.

  • 35.
    Lundgren, Joakim
    et al.
    Division of Energy Engineering, Luleå University of Technology.
    Ji, Xiaoyan
    Division of Energy Engineering, Luleå University of Technology.
    Grip, Carl-Erik
    Division of Energy Engineering, Luleå University of Technology.
    Wetterlund, Elisabeth
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Svensson, Elin
    Division of Heat and Power Technology, Chalmers.
    Harvey, Simon
    Division of Heat and Power Technology, Chalmers.
    Lundmark, Robert
    Economics Unit, Luleå University of Technology.
    Alriksson, Stina
    School of Natural Sciences, Linnaeus University.
    Wang, Chuan
    PRISMA, Swerea MEFOS AB.
    Resin, Monika
    Billerud Karlsborg AB.
    Lundstedt, Karin
    Billerud Karlsborg AB.
    Brännström, Mattias
    Billerud Karlsborg AB.
    Hoffner, Nils
    Billerud Karlsborg AB.
    Development of a regional-economic process integration model for Billerud Karlsborg AB2010Report (Other academic)
    Abstract [en]

    The pulp and paper industry is an energy-intensive industrial sector that faces several challenges such as increased competition and rising feedstock and energy prices. To adress this, it is crucial for the industry to improve the material and energy efficiencies to the greatest possible extent. Process integration methods like pinch analysis and mathematical programming are useful tools for evaluating possible process alternatives, i.e. applications of new technologies, changes to new equipment and/or different operating conditions. Development of industrial energy combines is an interesting approach towards an overall optimization of energy and material flows. One problem is often that there are a large number of essentially different actors and financers that are interested in studying other parameters than those that are normally investigated in process integration studies, for example national or regional economics and various social values.In this project, engineering, economic and statistical tools and methods have been applied separately as well as in combination for different types of investigations conducted at the paper and pulp mill Billerud Karlsborg AB in Kalix, Sweden. One main objective has been to develop a process integration model of the mill based on the reMIND method to be used for introductory process simulations of the existing mill configuration. Additionally, pinch analysis has been used to identify alternatives for energy savings in the mill. Another objective has been to develop a regional economic market model (ReCOM) that should be suitable for analysis and predictions of price changes on relevant feedstock markets. A more simplified model based on the reMIND method has been used for intitial studies on how the mill can be turned into a biorefinery. The main purpose of that work has been to investigate if biomass gasification can be economically interesting for the mill and if so, under what boundary conditions. A statistical technique, conjoint analysis, has been used to study and analyze the attitude of employed people at the mill to changes in the production process that may affect for example the local and global environment etc. Finally, possible interactions between the different models and tools have been investigated.The reMIND modelling of the existing mill configuration has showed several alternatives to save steam and fuel. For example, if the wood-chips supplied to the digester is pre-heated from a temperature of 0°C to say 60°C by the use of low grade residual heat, approximately 1.5 ton per hour of 10 bar steam or 5 ton per hour of biomass fuels can theoretically be saved. Furthermore, if the inlet liquor temperature to effect 4 of the evaporation plant increases from 85 to 105°C, the steam used for evaporation decreases from 77 to 66 ton per hour and as a consequence, the biomass fuel supply to the bark boiler decreases from 51 to 39 ton per hour. This, however, also leads to a slightly reduced electricity production, from 35 to 34 MW due to a reduced production of the high pressure steam.The results from the developed ReCOM model, suggest that only none to small changes in the fibrous input prices from an increase in the fuel price (affecting the forestry sector) and a small price increase as a result from a reduced supply of purchasable wood-chips and pulp wood. The small effect that increasing fuel prices has on the fibrous input prices can largely be explained by the relatively small cost share that fuels have in the forestry sector. An increase of the labour costs would most likely have a larger impact. As for the price effect from a reduction in the supply of purchasable wood-chips, there is a substitution possibility between purchased and internally produced wood-chips for the pulp mill. However, when the limit for how much internally produced wood-chips is reached its will probably results in larger price effectsThe Pinch study of the mill indicated that there is a theoretical steam-saving potential of 18.5 MW, corresponding to 12% of the current steam demand. Two different retrofit proposals were suggested for how to achieve specific steam saving levels in practice. According to a basic retrofit proposal, a steam saving of 5.8 MW could be achieved at an investment cost of 7 MSEK while a more rigorous retrofit would enable steam savings of 11 MW at an investment cost of 14.5 MSEK. An approach for using these results in a reMIND model of the mill has also been proposed.The results from the more simplified reMIND modelling have showed that if the mill starts to produce DME via biomass gasification, the necessary policy support to make it economically feasible ranges from 92-561 SEK per MWh biofuel (DME) over four different future scenarios. This could be compared to the Swedish exemption from energy tax on biofuels, which currently amounts to approximately 275 SEK per MWh. It is also concluded that biomass gasification results in a larger net CO2 reduction when integrated with the pulp and paper mill, than when the mill and the gasification plant operate separately.The conjoint analysis showed that it is possible to find groups of respondents that were unknown prior to the study. If an organisation wants to implement a change in the process, conjoint analysis can be used to identify groups of participants with similar preferences and then tailor information to suit these specific groups.Many possibilities for the different models to interact have been identified and illustrated. The interaction between the reMIND method and ReCOM is based on exchanging information on fibrous input prices and quantities and conducted through an iterative process. The results indicate that the models can interact to produce more robust and reliable conclusions regarding optimal resource utilization suggesting that the described approach is feasible and that further research efforts can be made to extend the models. Pinch analysis and reMIND modelling has in other studies shown to be able to interact iteratively. In this study, the retrofit proposals obtained from the pinch analysis could serve as inputs to future reMIND modelling. Another interaction between reMIND and pinch analysis that has been identified during the project is to use pinch analysis to evaluate the opportunity to pre-heat certain process streams. The results from a conjoint analysis are quantitative in form of regression coefficients. However, to use these numbers for example in a Pareto front analysis will be difficult as the numbers has no monetary, energy or emission unit. Nonetheless, conjoint analysis can interact in many different ways with ReCOM as well as the reMIND models. For example, to choose scenarios to be modelled in ReCOM where the factors in the conjoint analysis can be tailored to indicate how the market would respond in a hypothetical situation. Conjoint analysis can be used to weight different factors in the reMIND model. The weighting can possibly also be used in the ReCOM model.This work has illustrated how the various engineering, economic and statistical methods and tools can be used both separately and in combination to help an industry towards more energy-efficient production processes.

  • 36.
    Alvors, Per
    et al.
    Kungl. Tekniska Högskolan, KTH, Stockholm.
    Arnell, Jenny
    Svenska Miljöinstitutet.
    Berglin, Niklas
    Innventia AB, Stockholm, Sweden.
    Björnsson, Lovisa
    Miljö- och energisystem, Lunds Tekniska Högskola, Lund.
    Börjesson, Pål
    Miljö- och energisystem, Lunds Tekniska Högskola, Lund.
    Grahn, Maria
    Department of Energy and Environment, Chalmers University of Technology, Sweden.
    Harvey, Simon
    Chalmers University of Technology, Dept. of Energy and Environment, Heat and Power Technology Division,Göteborg, Sweden.
    Hoffstedt, Christian
    Innventia AB, Stockholm, Sweden.
    Holmgren, Kristina
    Svenska Miljöinstitutet.
    Jelse, Kristian
    Svenska Miljöinstitutet.
    Klintbom, Patrik
    Volvo AB, Sweden.
    Kusar, Henrik
    Kemisk Teknologi, Kungliga Tekniska Högskolan, KTH, Stockholm.
    Lidén, Gunnar
    Department of Chemical Engineering, Lund University, Sweden.
    Magnusson, Mimmi
    Skolan för kemivetenskap, Kungliga Tekniska Högskolan, Stockholm.
    Pettersson, Karin
    Energi och miljö/Energiteknik, Chalmers Tekniska Högskola, Göteborg.
    Rydberg, Tomas
    Svenska Miljöinstitutet.
    Sjöström, Krister
    School of Chemical Science and Engineering, Kungliga Tekniska Högskolan, Stockholm.
    Stålbrand, Henrik
    Biokemi och Strukturbiologi, Lunds universitet, Lund.
    Wallberg, Ola
    Institutionen för kemiteknik, Lunds universitet, Lund.
    Wetterlund, Elisabeth
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Zacchi, Guido
    Institutionen för kemiteknik, Lunds universitet, Lund.
    Öhrman, Olof
    Institutionen för samhällsbyggnad och naturresurser, Luleå Tekniska universitet.
    Research and development challenges for Swedish biofuel actors – three illustrative examples: Improvement potential discussed in the context of Well-to-Tank analyses2010Report (Other academic)
    Abstract [en]

    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.

  • 37.
    Wetterlund, Elisabeth
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Optimal Localization of Biofuel Production on a European Scale2010Report (Other academic)
    Abstract [en]

    Second generation biofuels use non-food lignocellulosic feedstock, for example waste or forest residues, and have in general lower environmental impact than first generation biofuels. In order to reach the 2020 target of 10% renewable energy in transport it will likely be necessary to have a share of at least 3% second generation fuels in the EU fuel mix. However, second generation biofuel production plants will typically need to be very large which puts significant demand on the supply chain. This makes it necessary to carefully choose the geographic location of the production plants. A geographic explicit model for determining the optimal location of biofuel production has been developed at IIASA and has previously been used in studies on national scale. The model is based on mixed integer linear programming and minimizes the total cost of the supply chain, taking into account supply as well as demand side.

    The aim of this study is to develop the localization model to cover the European Union, and to use it to analyze how for example policy instruments and energy prices affect second generation biofuel production. Two policy instruments are considered; targeted biofuel support and a CO2 cost. Two feedstock types (forest residues and lignocellulosic waste) and three biofuel production technologies (methanol, Fischer-Tropsch diesel (FTD) and lignocellulosic ethanol) are included. For all three technologies heat for district heating is co-produced, and for FTD and ethanol electricity is also co-produced.

    The results show that with current energy prices and a targeted biofuel support equivalent to existing tax exemptions, over 1.5% of the total transport fuel demand can be met by second generation biofuels to a cost of 18 €/GJ. A CO2 cost of 100 €/tCO2results in a biofuel production equivalent to 2% of the total fuel demand, but to a higher cost (23 €/GJ). Targeted biofuel support promotes FTD which has higher biofuel efficiency, while a CO2 cost shifts the production towards ethanol due to larger co-production of electricity and high CO2 emissions from displaced electricity. In order to reach a 3% second generation fuel share to a reasonable cost waste feedstock must be used. If only forest residues are considered the biofuel supply cost exceeds 30 €/GJ, compared to around 11 €/GJ if low cost waste can also be used. The CO2 reduction potential is found to be strongly connected to the co-products, in particular electricity, with a high biofuel share not being a guarantee for a large decrease of CO2 emissions.

    It is concluded that in order to avoid suboptimal overall energy systems, heat and electricity applications should also be included when evaluating optimal bioenergy use. It is also concluded that while forceful policies promoting biofuels may lead to a high share of second generation biofuels to reasonable costs, this is not a certain path towards maximized reduction of CO2 emissions. Policies aiming at promoting the use of bioenergy thus need to be carefully designed in order to avoid conflicts between different parts of the EU targets for renewable energy and CO2 emission mitigation.

  • 38.
    Leduc, Sylvain
    et al.
    International Institute of Applied Systems Analysis (IIASA), Laxenburg, Austria.
    Wetterlund, Elisabeth
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Dotzauer, Erik
    Mälardalen University, Västerås.
    Biofuel production in Europe - Potential from lignocellulosic waste2010In: Proceedings Venice 2010, Third International Symposium on Energy from Biomass and Waste, Venice, Italy: CISA, Environmental Sanitary Engineering Centre , 2010Conference paper (Other academic)
    Abstract [en]

    The objective of this study is to analyze the biofuel potential in Europe fromlignocellulosic waste (wood waste and paper and cardboard waste). Ethanol from fermentationand Fischer-Tropsch (FT) diesel from gasification are the two biofuels considered. As thosebiofuels are not yet commercially available, the optimal locations of the production plants haveto be determined. The analysis is carried out with a geographic explicit model that minimizes thetotal cost of the biofuel supply chain. A mixed integer linear program is used for theoptimization. The results show that ethanol production plants are selected in a majority of thestudied cases. Ethanol plants are mainly set up in areas with a high heat demand and/or highelectricity or heat price, whereas FT diesel production plants are set up in areas where the heatdemand is low all year round. A high cost for emitting CO2 as well as high transport fossil fuelprices favor the selection of FT diesel over ethanol production plants. With a CO2 cost of 100€/tCO2 applied, the biofuel production from waste can potentially meet around 4% of theEuropean transport fuel demand.

  • 39.
    Wetterlund, Elisabeth
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Harvey, Simon
    Chalmers University of Technology.
    Biomass gasification integrated with a pulp and paper mill - the need for economic policies promoting biofuels2010In: Chemical Engineering Transactions, ISSN 1974-9791, Vol. 21, 1207-1212 p.Article in journal (Refereed)
    Abstract [en]

    In this study we analyse economic policy support for biofuels, with the aim to determine the amount of support necessary to make investments in a gasification based biorefinery producing DME (dimethyl ether) profitable for a pulp and paper mill. As a case the integrated Swedish pulp and paper mill of Billerud Karlsborg is studied, using mixed integer linear programming and different future energy market scenarios. The results show that the required support is strongly connected to the price ratio of oil to biomass, with the support ranging from 10 EUR/MWh biofuel (lower than the present tax exemption of 14 EUR/MWh) to 61 EUR/MWh. The required support is shown to be sensitive to changes of the capital cost, but not to the pulp and paper production rate of the host mill. It is concluded that strong policy instruments will be required for forest industry based biorefineries to be desirable for the future.

  • 40.
    Wetterlund, Elisabeth
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Pettersson, Karin
    Heat and Power Technology, Chalmers University of Technology.
    Magnusson, Mimmi
    Energy Processes, KTH (Royal Institute of Technology).
    Implications of system expansion for the assessment of well-to-wheel CO2 emissions from biomass based transportation2010In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 34, no 13, 1136-1154 p.Article in journal (Refereed)
    Abstract [en]

    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.

  • 41.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Improving the Environmental Performance of Biofuels with Industrial Symbiosis2009Manuscript (preprint) (Other academic)
    Abstract [en]

    In the production of biofuels for transport many critics have argued about the poor energy efficiency and environmental performance of the production industries. Optimism is thus set on the production of second generation biofuels, while first generation biofuels continue to dominate worldwide. Therefore it is interesting to consider how the environmental performance of first generation biofuel industries can be bettered. The field of industrial symbiosis offers many possibilities for potential improvements in the biofuel industry. It is shown in this research that integration between the respective biofuel industries is possible. This comes in the form of by-product synergies and utility synergies which can improve material and energy handling and environmental performance of the processes. Furthermore, the processes and products can gain increased environmental performance improvements by the adaption of a renewable energy system which will act as a utility provider for many industries in a symbiotic network. By-products may thereafter be upcycled through biogas production processes to generate both energy and a bio-fertilizer. A case study of an actual biofuel industrial symbiosis is also reviewed to provide support for these theories.

  • 42.
    Wetterlund, Elisabeth
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Biomass gasification in district heating systems - The effect of economic energy policies2010In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 87, no 9, 2914-2922 p.Article in journal (Refereed)
    Abstract [en]

    Biomass gasification is considered a key technology in reaching targets for renewable energy and CO2 emissions reduction. This study evaluates policy instruments affecting the profitability of biomass gasification applications integrated in a Swedish district heating (DH) system for the medium-term future (around year 2025). Two polygeneration applications based on gasification technology are considered in this paper: (1) a biorefinery plant co-producing synthetic natural gas (SNG) and district heat; (2) a combined heat and power (CHP) plant using integrated gasification combined cycle technology. Using an optimisation model we identify the levels of policy support, here assumed to be in the form of tradable certificates, required to make biofuel production competitive to biomass based electricity generation under various energy market conditions. Similarly, the tradable green electricity certificate levels necessary to make gasification based electricity generation competitive to conventional steam cycle technology, are identified. The results show that in order for investment in the SNG biorefinery to be competitive to investment in electricity production in the DH system, biofuel certificates in the range of 24-42 EUR/MWh are needed. Electricity certificates are not a prerequisite for investment in gasification based CHP to be competitive to investment in conventional steam cycle CHP, given sufficiently high electricity prices. While the required biofuel policy support is relatively insensitive to variations in capital cost, the required electricity certificates show high sensitivity to variations in investment costs. It is concluded that the large capital commitment and strong dependency on policy instruments makes it necessary that DH suppliers believe in the long-sightedness of future support policies, in order for investments in large-scale biomass gasification in DH systems to be realised.

  • 43.
    Martin, Michael
    Linköping University, Department of Management and Engineering, Environmental Technique and Management . Linköping University, The Institute of Technology.
    Biogas and Renewable Fuel Consumption: 2008 Figures for Linköping and Östergötland2009Report (Other academic)
    Abstract [en]

    Since the early 1990s, biogas consumption in Linköping has been increasing. With the expansion of infrastructure and vehicles capable of using biogas, Linköping is a leading model for biogas vehicles and fleet worldwide. Over the past few years biogas production has grown at a nearly constant rate of 20%. Since the start when only a limited amount of biogas was delivered primarily to the bus fleet, over 8.5 million m3 were delivered in 2009 (Svensk Biogas, 2009). Currently biogas is used in the public transport sector, vehicle fleets and more than a thousand personal vehicles. This development, along with the use of ethanol and biodiesel has led to a large increase in the use of renewable fuels in the municipality. While biogas and other renewable fuels make up only a small portion of the vehicle fuels consumed in the municipality, this portion continues to grow.

    Regional and national administrations have been challenged with European directives to include renewable energy in many sectors. In the transport sector, according to the European Directive 2003/30/EC all countries are to have a 5.75 % share of renewable energy in their transport sector by 2010 (EU, 2003). Thereafter, every member state is required to have a minimum of 10% in 2020. To meet these goals, member states are looking for solutions in various technologies, i.e. biofuels, hybrids, electric vehicles and hydrogen fuel cells. Currently, biofuels are being employed in nearly all the member states to fulfill the targets, with biogas, ethanol and biodiesel being most common. Sweden is a leader in the use of ethanol, while municipalities such as Linköping have put an emphasis in making use of industrial wastes to produce biogas. Locally produced renewable energy will thus provide vehicle fuel for the municipality of Linköping in order to reduce environmental impacts and meet vehicle fuel targets.

    Linköping has become a benchmarked city in the use and production of biogas. However, how much biogas and other renewable fuels does Linköping currently employ? The aim of this research paper is to analyze the use of renewable and fossil fuels in the region in order to quantify the percentage in relation to the European Directive 2003/30/EC. The research project will provide details regarding the share of petrol, diesel, biodiesel, ethanol and thereafter biogas in the current vehicle fuel consumption.

  • 44.
    Englund, Oskar
    et al.
    Chalmers University of Technology.
    Berndes, Göran
    Chalmers University of Technology.
    Johnsson, Hannes
    Chalmers University of Technology.
    Ostwald, Madelene
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, Faculty of Arts and Sciences.
    Environmental Impact Assessments: Suitable for supporting assessment of biofuel sustainability?2011Report (Other (popular science, discussion, etc.))
    Abstract [en]

    The European Union requires that 10% of the energy in the transport sector shall come from renewable sources by 2020. In addition, biofuels used for transport need to fulfill certain sustainability requirements set out in the Renewable Energy Directive (RED). To meet these requirements, the EU will need to produce and import large amounts of sustainable biofuels. Therefore, there is a need for ways to verify the sustainability of imported biofuels, so that unsustainable biofuels can be avoided. One strategy may involve analyzing Environmental Impact Assessment (EIA) reports (EIRs) conducted for specific biofuel projects. For EIRs to be useful as such information sources they need to be sufficiently comprehensive in relation to the RED but also sufficiently reliable. In this study, 19 biofuel project EIRs are analyzed with respect to how they cover the RED sustainability considerations. In addition, EIA legislation, requirements, quality, and enforcement are discussed to determine not only whether EIRs can be sufficiently comprehensive, but also sufficiently reliable for supporting information to studies intended to assess the sustainability of biofuels, from an RED perspective. Notable differences between EIRs for different types of projects were found. EIRs for projects including both plantation establishment and the construction of a biofuel plant had better RED coverage than EIRs for projects including either the plantations or the biofuel plant. As might be expected, EIAs for “plantation projects” generally leave out features related to biofuel processing, and EIAs for “biofuel plant” projects generally leave out features related to feedstock production. In general, EIA legislation is insufficient and most target countries seem to have rather low potential to enforce legislation. Several additional EIA-related problems need to be overcome in order for EIRs to be regarded as sufficiently reliable information tools.

  • 45.
    Henders, Sabine
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Palm, Matilda
    Physical Resource Theory, Chalmers University of Technology, Göteborg.
    Englund, Oskar
    Physical Resource Theory, Chalmers University of Technology, Göteborg.
    Sustainability criteria for land use activities in the carbon market2011Report (Other academic)
  • 46.
    Baas, Leenard
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Planning and Uncovering Industrial Symbiosis: Comparing the Rotterdam and Östergötland regions2011In: Business Strategy and the Environment, ISSN 0964-4733, E-ISSN 1099-0836, Vol. 20, no 7, 428-440 p.Article in journal (Refereed)
    Abstract [en]

    Industrial ecology is defined as the study of material and energy flows through industrial systems and as such may focus on a geographic area, resource and/or industry sector. In these types of setting, industrial ecology is also often known as industrial symbiosis (IS). The proximity of companies in industrial estates facilitates the linking of utilities and the exchange of wastes and by-products, which may eventually be useful inputs for adjacent industrial processes. The typical model that has been applied in several regions of the world is one where an anchor-tenant organization with energy and by-product linkages is connected to companies physically located nearby. In the case of biomass symbiosis, however, the resource chains are not explicitly arranged by their industrial setting and the supply of waste and by-products is able to be organized in a more scattered way.

    In this article, the role of industrial symbiosis is analyzed in respect of the planned industrial symbiosis activities in the Rotterdam Harbour and Industry Complex in the Netherlands and in the application of renewable energy in the Östergötland region in Sweden.

    The objective of this article is to discuss the similarities and differences between the planned industrial symbiosis activities in Rotterdam and the unplanned biomass and industrial symbiosis activities in the Östergötland region. By presenting this knowledge in this article, it is anticipated that further development of industrial symbiosis application processes may be achieved. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.

  • 47.
    Leduc, Sylvain
    et al.
    International Institute of Applied Systems Analysis, Laxenburg, Austria.
    Wetterlund, Elisabeth
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Dotzauer, Erik
    Mälardalen University, Västerås.
    Kindermann, Georg
    International Institute of Applied Systems Analysis, Laxenburg, Austria.
    CHP or biofuel production in Europe?2012In: Energy Procedia, ISSN 1876-6102, Vol. 20, 40-49 p.Article in journal (Refereed)
    Abstract [en]

    In this study, the opportunity to invest in combined heat and power (CHP) plants and second-generation biofuel production plants in Europe is investigated. To determine the number and type of production plants, a mixed integer linear model is used, based on minimization of the total cost of the whole supply chain. Different policy scenarios are studied with varying values of carbon cost and biofuel support. The study focuses on the type of technology to invest in and the CO2 emission substitution potential, at constant energy prices. The CHP plants and the biofuel production plants are competing for the same feedstock (forest biomass), which is available in limited quantities. The results show that CHP plants are preferred over biofuel production plants at high carbon costs (over 50 EUR/tCO2) and low biofuel support (below 10 EUR/GJ), whereas more biofuel production plants would be set up at high biofuel support (over 15 EUR/GJ), irrespective of the carbon cost. Regarding the CO2 emission substitution potential, the highest potential can be reached at a high carbon cost and low biofuel support. It is concluded that there is a potential conflict of interest between policies promoting increased use of biofuels, and policies aiming at decreased CO2 emissions.

  • 48.
    Kuchler, Magdalena
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Stability rather than change is the order of the day: the case of second-generation biofuelsManuscript (preprint) (Other academic)
    Abstract [en]

    This paper takes a critical look at the conceptualization of second-generation bioenergy based on the institutional discourse pursued by food and agriculture-, energy security-, and climate change-focused international organizations. Set against the backdrop of two distinct perspectives on the understanding and role of innovation, progress, and the future in contemporary capitalist societies, the paper explores how advanced biofuels are distinguished from their conventional predecessors, how the intention to shift from first- to second-generation production patterns is facilitated and justified, and the role of innovation in pursuing this shift. I argue that the notions of “new” and “innovative” put forward in the advanced biofuel project not only exemplify the illusion of an emptied and decontextualized future, but also express an ideological view devoid of utopian potential.

  • 49.
    Kuchler, Magdalena
    et al.
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Linnér, Björn-Ola
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Challenging the food vs. fuel dilemma: Genealogical analysis of the biofuel discourse pursued by international organizations2012In: Food Policy, ISSN 0306-9192, Vol. 37, no 5, 581-588 p.Article in journal (Refereed)
    Abstract [en]

    This paper looks critically at how food and agriculture-, energy security-, and climate change-oriented international organizations have consolidated and modified the biofuel discourse in relation to the agricultural system. Using Foucault-based genealogical analysis of discursive formations, the paper traces the last 20 years of institutions’ biofuel debate in relation to rural production. We find that the prevalent motive is an aspiration to combine the agriculture and energy markets into one, which prompts structural changes and challenges in the rural sector. This has implications for the future role and shape of global agriculture and – contrary to the food vs. fuel perspective – calls for re-conceptualizing the biofuel debate as the food vs. food dilemma.

  • 50.
    Martin, Michael
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Production synergies in the current biofuel industry: Opportunities for development2012In: Biofuels, ISSN 1759-7269, Vol. 3, no 5, 545-554 p.Article in journal (Refereed)
    Abstract [en]

    Background: With criticism about the economic viability and environmental performance of biofuels, theuse of byproducts and integration with external industries could be achieved to improve their performanceand provide further use for byproducts and wastes. Methodology: A review of potential byproduct andutility exchanges between biofuel and external industries has been documented in this article through aliterature review and brainstorming workshop, and results have been classified based on their interactions.Results: It has been found that byproduct exchanges, especially those between biofuel industries, andexchanges between the biofuel industries and the food, feed, agriculture and energy industries, offer manypotential exchanges. Conclusion: The identified synergies offer possibilities for potential collaborationpartners in symbiotic exchanges with the biofuel industry.

12 1 - 50 of 92
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf