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  • 1.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Strand, Michael
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Melting Characteristics and Morphology of Bottom Ash and Filter Ash of the Circulating Fluidized Bed Boiler2013Ingår i: 21st European Biomass Conference and Exhibition, Copenhagen, Danmark, 3rd-7th June, 2013, ETA-Florence Renewable Energies , 2013, s. 1189-1191Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this work was to investigate the melting characteristics and morphology of filter ash and bottom ash with and without 7% of peat addition to the fuel of the circulating fluidized bed boiler. The samples were characterized by simultaneous thermal analysis (STA) and scanning electron microscope (SEM). The STA results indicate that the filter ash melts at 1140oC with 10 wt% of the mass loss and Bottom ash partially melts at 1170oC with below 2 wt% of the mass loss. The low melting point of the filter ash is due to the high concentration of the alkali metals in the filter ash. Similar trends were observed in the case of fly ash and bottom ash with peat admixture to the fuel. Furthermore the elementary analysis via scanning electron microscopy, coupled with energy-dispersive X-ray analysis showed that 7% of peat addition to the fuel does not significantly effect on the ash composition.

  • 2.
    Bennani, Mohamed
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för informatik (IK).
    Smarter technologies towards Greener Homes: A Human-Centred Approach2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Advances in technology continuously reshape habits, behaviours and interactions at individual, organisational and societal levels. Information and Communication technology (ICT) is pervasive, and is the bearer of crucial information, analysis and responses to the recipient. It assists in processes such as understanding phenomena and taking appropriate action. It also provides communication means, platforms and tools to interact with one another.

    In the United Kingdom’s (UK) Energy industry, smart meters are currently being deployed by energy suppliers to their customers. These are presented as a revolutionary device that supports a more efficient energy use at home and/or in the workplace, and helps customers save on their energy bill and reduce carbon footprint.

    Using interpretivist phenomenological Human-centred qualitative research, The thesis work explores the impact of using smart meter devices, as perceived by UK customers, in helping to monitor, use and manage energy consumption at home. Also, the study looks into alternative technology and customers’ expectations in the context of energy efficiency. And finally, the principles of a design is presented to respond to customers demands and desires. Passive participant observation, Future workshop and inspiration cards session are the methods and techniques applied in this research to collect  data.

    The findings constitute good grounds for individual consumers to be aware of the opportunities made available by alternative technology. At organisational level it is a basis for energy suppliers to change their behaviour towards a changing demand and adapt by switching their core business to supplying Information and analysis as well as energy efficiency management solutions. At societal level government bodies and regulating agencies can tackle sustainability and green energy issues by controlling the profit driven character of privatised energy companies and responding to real market demand as perceived by consumers.

    Emerging technologies present opportunities that have the capabilities of breaking the status quo of energy supply industry in the UK as well as the rest of world.

    The value of this research is to show customers’ perceived reality and expectations, as well as opportunities to change the way energy is supplied and consumed.

  • 3.
    Bonakdar, Farshid
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Dodoo, Ambrose
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Gustavsson, Leif
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Cost-optimum analysis of building fabric renovation in a Swedish multi-story residential building2014Ingår i: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 84, s. 662-673Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, we analysed the cost-optimum level of building fabric elements renovation in a multi-story residential building. We calculated final energy use for space heating of the building considering a wide range of energy efficiency measures, for exterior walls, basement walls, attic floor and windows. Different extra insulation thicknesses for considered opaque elements and different U-values for new windows were used as energy efficiency measures. We calculated difference between the marginal saving of energy cost for space heating and the investment cost of implemented energy efficiency measures, in order to find the cost-optimum measure for each element. The implications of building lifespans, annual energy price increase and discount rate on the optimum measure were also analysed. The results of the analysis indicate that the contribution of energy efficiency measures to the final energy use reduces, significantly, by increasing the thickness of extra insulation and by reducing the U-value of new windows. We considered three scenarios of business as usual (BAU), intermediate and sustainability, considering different discount rates and energy price increase. The results of this analysis suggest that the sustainability scenario may offer, approximately, 100% increase in the optimum thickness of extra insulation compare to BAU scenario. However, the implication of different lifespans of 40, 50 or 60 years, on the optimum measure appears to be either negligible or very small, depending on the chosen scenario. We also calculated the corresponding U-value of the optimum measures in order to compare them with the current Swedish building code requirements and passive house criteria. The results indicate that all optimum measures meet the Swedish building code. None of the optimum measures, however, meet the passive house criteria in BAU scenario. This study suggests that the employed method of building renovation cost-optimum analyses can be also applied on new building construction to find the cost-optimum design from energy conservation point of view.

  • 4.
    Brandin, Jan
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Hulteberg, Christain
    Kusar, Henrik
    Kungliga tekniska högskolan.
    A review of thermo-chemical conversion of biomass into biofuels: focusing on gas cleaning and up-grading process steps2017Rapport (Övrig (populärvetenskap, debatt, mm))
    Abstract [sv]

    Det är en stor utmaning att ersätta fossila bränslen inom transportsektorn, en tilltalande lösning är att använda biomassa och avfall för produktion av förnyelsebara drivmedel. Termokemisk omvandling av biomassa är ett lovande sätt för att producera olika sorters syntetiska drivmedel, då främst genom förgasningsteknik. En av de främsta utmaningarna i att använda termokemisk omvandling av biomassa och avfall är en rening och uppgradering av rågasen som produceras i förgasaren. Dessa material som är tänkta att ersätta olja och kol innehåller betydande mängder av alkaliska-, oorganiska-, svavel- och klor-föreningar.

    De olika renings- och uppgraderingsstegen påverkar den totala verkningsgraden på hela processen, därför blir hanteringen av värme i de olika process strömmarna viktiga, som för alla processer i flera steg. Dessvärre, har de tillgängliga konventionella gas filtreringsenheterna för att ta bort partiklar och orenheter, och även efterföljande katalytiska omvandlingssteg, lägre optimala arbetstemperaturer än driftstemperaturen hos förgasningsenheterna.

    Denna rapport fokuserar på pågående forskning och utveckling för att hitta ny teknik och lösningar när det gäller rening och uppgradering av rågas till syntesgas, samt efterföljande bränslesyntesprocesser, såsom hetgas-filtrering, smarta uppvärmnings lösningar och högre grad av integrationsprocess, samt katalysatorer som är mer tåliga mot deaktivering. Detta innebär att temperaturen bör vara så hög som möjligt för varje enskild renings- och en uppgraderingsenhet, likväl måste temperaturen och trycket hos den renade syntesgasen uppfylla kraven för nedströms bränslesyntes, d.v.s. Fischer-Tropsch-diesel eller metanol.

    Ett antal orenheter behöver tas bort innan gasen som producerats i förgasaren kan användas, dessa inkluderar partiklar, tjäror, svavelföreningar och ammoniak. Partiklar bildas alltid vid förgasning, oberoende av vilken typ av förgasningsteknik som används, en första grovseparation utförs i en eller flera cyklonfilter vid höga temperaturer. För att separera de finare partiklarna används därefter olika keramiska- eller textilfilter, ett problem är dock kondensation av tjära i filtren, mycket arbete utförs på att försöka uppnå filtrering vid så hög temperatur som möjligt, så att man slipper tjärproblemen.

    Det största hindret när det gäller rening och uppgradering av gaserna är tjära. För att bli av med tjäran från produktgasen finns ett antal olika alternativ, men det väsentligaste är att själva förgasaren drivs vid optimala förhållanden för att minimera att tjära bildas överhuvudtaget.

    För förgasning med fluidiserad bädd och entrained flowförgasning skulle det första steget kunna vara katalytisk tjärkrackning efter att ha avlägsnat alla partiklar. Vid förgasning i fluidiserad bädd kan aktiva katalysatorer tillsättas till den fluidiserande bädden som kan kracka tjäran redan i bädden och hindra att ytterligare eventuell tjära bildas. Katalysatorer som används är främst naturliga mineraler, såsom dolomit och olivin, dessa användes normalt vid reformering eller krackning av kolväten.

    Tjäran kan reformeras till vätgas och kolmonoxid genom termisk reformering såsom när temperaturen höjs till 1300ºC och tjäran sönderfaller. En annan metod för att avlägsna tjära från gasen är att tvätta gasen med hjälp av het olja (200-300ºC). Tjäran löser sig i den heta oljan, som delvis kan vara regenererad och den återstående tjärhaltiga delen kan antingen brännas eller återföras till förgasaren för förgasning.

    Svavelföreningar är en annan viktig kontaminering som behöver tas bort ur gasen, svavelhalten i gasen beror främst på vilken typ av biomassa som används. Nivåer över 100 ppm inte är ovanligt och är inte acceptabelt för efterföljande nedströms katalytiska processer, eller om utsläppen av t.ex. SO2 ska hållas nere.

    Svavel kan separeras genom adsorption med ZnO som är en irreversibel process, eller genom kommersiellt tillgängliga reversibla adsorbenter som kan användas. Ytterligare alternativ är att tvätta/skrubba gasen med en aminlösning. Om ett reversibelt alternativ används kan elementärt svavel framställas med hjälp av Claus-processen.

    Ammoniak bildas vid förgasning och nivåer runt 3000 ppm är inte ovanligt, men anses vanligtvis inte ett problem efterföljande nedströms processer. Om gasen förbränns, kan dock kväve eller i värsta fall NOx (så kallad bränsle NOx) bildas. Det finns dock indikationer på att problem kan uppstå, speciellt när förgasning följs av nedströms katalytiska processer, exempelvis vid ångreformering där katalysatorn kan deaktiveras vid långvarig exponering för ammoniak

    Sammansättningen på produktgasen beror framförallt på valet av förgasningsteknik, vilket förgasningsmedel som används, samt viken sorts biomassa sam används. Valet av förgasningsmedel, dvs. luft, syre, vatten, är extra viktigt eftersom det har en direkt inverkan på sammansättningen och kvaliteten hos gasen. Valet av förgasningsmedel påverkar också vilka renings- och uppgraderingsprocesser som kan användas och lämpar sig bäst för olika slutanvändningstillämpningar som t.ex. drivmedel eller för gröna kemikalier.

    Idealt består en syntesgas som är uppgraderad av vätgas och kolmonoxid i korrekt förhållande, med mycket låga halter vatten och koldioxid. Detta innebär att tjäror, partiklar, alkalisalter och oorganiska föreningar, som nämnts tidigare, måste avlägsnas för de flesta tillämpningarna. Genom att använda syre som förgasningsmedel, i stället för luft, kan innehållet av kväve i gasen minimeras, så man undviker efterföljande dyrbar separation av kväve.

    Sammanfattningsvis finns det ett antal olika användningsområden för olika producerade syntesgaser. De olika tillämpningarna kommer att diskuteras i rapporten med början med produktion av vätgas, följt av framställning av syntetisk naturgas (SNG), metanol, dimetyleter, Fischer-Tropsch-diesel och syntes av högre alkoholer, samt beskrivningar av metoder som kombinerar dessa. Processystemen är olika där syntes av SNG och metanol begränsas jämvikt, medan syntes av dimetyleter, (DME), FT-diesel och alkoholer inte är jämviktsberoende. Samtliga reaktioner är exoterma, med undantag för ångreformering av metan och tjäror, vilket medför att det är viktigt att kontrollera temperaturökningen i reaktorerna. Dessutom måste syntes av metanol utföras vid högt tryck (50-100 bar) för att vara industriellt gångbar.

    För att hålla nere kapitalkostnaderna för hela reningssystemet och systemets effektivitet behöver man kompromissa, eftersom hanteringen av fast avfall, t.ex. aska, absorberande medel, bäddmaterial och avloppsvatten alla innebär kostnader.

    Att installera väldigt effektiva katalysatorer resulterar i dyrare gasrening på grund av onödiga kostnader, men nedströms syntesprocesser kommer att dra nytta av effektiv gasrening som förlänger katalysatorernas livstid, särskilt för Fischer-Tropsch-diesel, och DME/metanol syntes. Generellt måste katalysatorerna i de olika uppgraderingsprocesserna vara mer stabila och motståndskraftiga mot olika typer av deaktivering.

    Slutligen är process-intensifiering ett viktigt område för utveckling inom hela kemiindustrin som bland annat omfattar integration av både syntes och separationssteg, med olika former av avancerad värmeväxling med värmeintegration för att öka värmeöverföringshastigheten, och att kombinera exoterma och endoterma reaktioner. Därför är det nödvändigt med nya innovativa lösningar för rening och uppgradering av gaserna för att få fram kostnadseffektiva och effektiva tillämpningar.

  • 5.
    Brandin, Jan
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Odenbrand, Ingemar
    Lund University .
    Poisoning of SCR Catalysts used in Municipal Waste Incineration Applications2017Ingår i: Topics in catalysis, ISSN 1022-5528, E-ISSN 1572-9028, Vol. 60, nr 17-18, s. 1306-1316Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A commercial vanadia, tungsta on titania SCRcatalyst was poisoned in a side stream in a waste incinerationplant. The effect of especially alkali metal poisoningwas observed resulting in a decreased activity at long timesof exposure. The deactivation after 2311 h was 36% whilethe decrease in surface area was only 7.6%. Thus the majorcause for deactivation was a chemical blocking of acidicsites by alkali metals. The activation–deactivation modelshowed excellent agreement with experimental data. Themodel suggests that the original adsorption sites, fromthe preparation of the catalyst, are rapidly deactivated butare replaced by a new population of adsorption sites dueto activation of the catalyst surface by sulphur compounds(SO2, SO3)in the flue gas.

  • 6.
    Bravo, Giangiacomo
    et al.
    Linnéuniversitetet, Fakulteten för samhällsvetenskap (FSV), Institutionen för samhällsstudier (SS).
    Pardalis, Georgios
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Mahapatra, Krushna
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Mainali, Brijesh
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Physical vs. Aesthetic Renovations: Learning from Swedish House Owners2019Ingår i: Buildings, ISSN 2075-5309, E-ISSN 2075-5309, Vol. 9, nr 1, artikel-id 12Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, we identify the socio-economic attributes and attitudes that have influencedhouse owners in renovating their homes in the past. Our study is based on responses to an onlinequestionnaire survey of 971 house owners living in Kronoberg County in Sweden. Results showedthat the interest and willingness of the house owners to perform a renovation varied dependingon their demographic background and the age of the house. The latter positively affected pastrenovations, only when combined with the residence time. Furthermore, the age of house ownersstrongly and positively affected the probability of performing aesthetic type of renovations, becauseof a long time of residence in the house. Younger, town living, and highly educated house ownersseem to be more concerned regarding saving energy, which motivated them to perform physicalrenovations on their house. Our results also suggest that income, level of education, and place ofresidence have an effect on renovation decisions only through their effect on the energy concern ofhouse owners, and a varied effect on renovation decisions, when combined with the time of residencein the house.

  • 7. Bäck, Andreas
    et al.
    Grubbström, Jörgen
    Ecke, Holger
    Pettersson, Jens
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Strand, Michael
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Operation of an Electroctrostatic Precipitator at a 30 MWth oxyfuel plant2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The performance of a full-scale ESP was studied at the Vattenfall AB oxyfuel pilot plant in SchwarzePumpe. The lignite-fired boiler has a 30 MWth top-mounted pulverized coal burner and was operated under conventional air combustion as well as oxyfuel combustion. The ESP was operated with varying numbers of fields in service and at different current/voltage settings. Particle number size distributionsdownstream the ESP were established on-line in the size range 0.015-10 μm, using an electrical mobility spectrometer and an aerodynamic particle sizer. The particle size distribution at oxyfuel operation was qualitatively very similar to the results obtained for air-firing. Gravimetric measurementsof total fly ash concentration showed outlet emissions below 5 mg/Nm3 when the ESP was operatedwith two fields in service at oxyfuel conditions.

  • 8.
    Carlsson, Bo
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Meir, Michaela
    Aventa AS, Norway.
    Rekstad, John
    Aventa AS, Norway.
    Preiss, Dieter
    AEE-INTEC, Austria.
    Ramschak, Thomas
    AEE-INTEC, Austria.
    Replacing traditional materials with polymeric materials in solar thermosiphon systems: Case study on pros and cons based on a total cost accounting approach2016Ingår i: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 125, s. 294-306Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The pros and cons of replacing traditional materials with polymeric materials in solar thermosiphon systems were analysed by adopting a total cost accounting approach.

    In terms of climatic and environmental performance, polymeric materials reveal better key figures than traditional ones like metals. In terms of present value total cost of energy, taking into account functional capability, end user investment cost, O&M cost, reliability and climatic cost, the results suggest that this may also be true when comparing a polymeric based thermosiphon system with a high efficient thermosiphon system of conventional materials for DHW production in the southern Europe regions. When present values for total energy cost are assessed for the total DHW systems including both the solar heating system and the auxiliary electric heating system, the difference in energy cost between the polymeric and the traditional systems is markedly reduced.

    The main reason for the difference in results can be related to the difference in thermal performance between the two systems. It can be concluded that the choice of auxiliary heating source is of utmost importance for the economical competiveness of systems and that electric heating may not be the best choice.

  • 9.
    Dhakal, Shobhakar
    et al.
    Asian Institute of Technology, Thailand.
    Srivastava, Leena
    TERI School of Advanced Studies, India.
    Sharma, Bikash
    ICIMOD, Nepal.
    Palit, Debajit
    TERI, India.
    Mainali, Brijesh
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Nepal, Rabindra
    Massey University, New Zealand.
    Purohit, Pallav
    nternational Institute for Applied Systems Analysis (IIASA), Austria.
    Goswami, Anandajit
    TERI School of Advanced Studies, India.
    Malikyar, Ghulam Mohd
    National Environmental Protection Agency, Afghanistan.
    Wakhley, Kul Bahadur
    Royal Government of Bhutan, Bhutan.
    Meeting Future Energy Needs in the Hindu Kush Himalaya2019Ingår i: The Hindu Kush Himalaya Assessment: Mountains, Climate Change, Sustainability and People / [ed] Philippus Wester, Arabinda Mishra, Aditi Mukherji, Arun Bhakta Shrestha, Springer, 2019, s. 167-207Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    As mentioned in earlier chapters, the HKH regions form the entirety of some countries, a major part of other countries, and a small percentage of yet others. Because of this, when we speak about meeting the energy needs of the HKH region we need to be clear that we are not necessarily talking about the countries that host the HKH, but the clearly delineated mountainous regions that form the HKH within these countries. It then immediately becomes clear that energy provisioning has to be done in a mountain context characterized by low densities of population, low incomes, dispersed populations, grossly underdeveloped markets, low capabilities, and poor economies of scale. In other words, the energy policies and strategies for the HKH region have to be specific to these mountain contexts.

  • 10.
    Dodoo, Ambrose
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Gustavsson, Leif
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Effect of energy efficiency requirements for residential buildings in Sweden on lifecycle primary energy use2014Ingår i: Energy Procedia: INTERNATIONAL CONFERENCE ON APPLIED ENERGY, ICAE2014 / [ed] Yan, J; Lee, DJ; Chou, SK; Desideri, U; Li, H, Elsevier, 2014, Vol. 61, s. 1183-1186Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this study we analyze the lifecycle primary energy use of a wood-frame apartment building designed to meet the current Swedish building code or passive house criteria, and heated with district heat or bedrock heat pump. We employ a lifecycle perspective methodology and determine the production, operation and end-of-life primary energy use of the buildings. We find that the passive house requirement strongly reduces the final energy use for heating compared to the current Swedish building code. However, the primary energy use is largely determined by the energy supply system, which is generally outside the mandate of the building standards. Overall, buildings with district heating have lower life-cycle primary energy use than alternatives heated with heat pump. The primary energy for production is small relative to that for operation, but it is more significant as the energy-efficiency standard of building improves and when efficient energy supply is used. Our results show the importance of a system-wide lifecycle perspective in reducing primary energy use in the built environment. A life cycle primary energy perspective is needed to minimize overall primary energy use, and future building energy-efficiency standards may reflect the full energy use during a building's life cycle. This could include primary energy implications for production, operation and end-of-life of buildings.

  • 11.
    Dodoo, Ambrose
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Gustavsson, Leif
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Energy use and overheating risk of Swedish multi-storey residential buildings under different climate scenarios2016Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 97, s. 534-548Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, the extent to which different climate scenarios influence overheating risk, energy use and peak loads for space conditioning of district heated multi-storey buildings in Sweden are explored. Furthermore, the effectiveness of different overheating control measures and the implications of different electricity supply options for space cooling and ventilation are investigated. The analysis is based on buildings with different architectural and energy efficiency configurations including a prefab concrete-frame, a massive timber-frame and a light timber-frame building. Thermal performance of the buildings under low and high Representative Concentration Pathway climate scenarios for 2050–2059 and 2090–2099 are analysed and compared to that under historical climate of 1961–1990 and recent climate of 1996–2005. The study is based on a bottom-up methodology and includes detailed hour-by-hour energy balance and systems analyses. The results show significant changes in the buildings’ thermal performance under the future climate scenarios, relative to the historical and recent climates. Heating demand decreased significantly while cooling demand and overheating risk increased considerably with the future climate scenarios, for all buildings. In contrast to the cooling demand, the relative changes in heating demand of the buildings under the future climate scenarios are somewhat similar. The changes in the space conditioning demands and overheating risk vary for the buildings. Overheating risk was found to be slightly higher for the massive-frame building and slightly lower for the light-frame building.

  • 12.
    Dodoo, Ambrose
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Gustavsson, Leif
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Bonakdar, Farshid
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Effects of future climate change scenarios on overheating risk and primary energy use for Swedish residential buildings2014Ingår i: Energy Procedia: INTERNATIONAL CONFERENCE ON APPLIED ENERGY, ICAE2014 / [ed] Yan, J; Lee, DJ; Chou, SK; Desideri, U; Li, H, Elsevier, 2014, Vol. 61, s. 1179-1182Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this study we use dynamic computer simulation modelling to investigate the potential impact of future climate change scenarios on the risk of overheating and annual primary energy requirements for space heating and cooling of residential buildings in Växjö, Sweden. The buildings are designed to the energy efficiency level of conventional or passive house, and are assumed to be heated with district heating and cooled with mechanical cooling system. We compare different climate change scenarios to a baseline which represents the climate data of Växjö for 1996-2005. The climate change scenarios are based on projected temperature changes under the representative concentration pathways (RCP) 4.5 and 8.5 scenarios. The result shows that the risk of overheating increases under the climate change scenarios. Furthermore space heating demand is reduced and cooling demand is increased for the analyzed buildings, and the changes are proportionally more significant for the passive compared to the conventional building.

  • 13.
    Dodoo, Ambrose
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Tettey, Uniben Yao Ayikoe
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Gustavsson, Leif
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    On input parameters, methods and assumptions for energy balance and retrofit analyses for residential buildings2017Ingår i: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 137, s. 76-89Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study we explore key parameter values, methods and assumptions used for energy balance modelling of residential buildings in the Swedish context and analyse their effects on calculated energy balance of a typical multi-storey building from 1970s and on energy savings of energy efficiency retrofit measures. The parameters studied are related to microclimate, building envelope, occupancy behaviour, ventilation, and heat gains from electric appliances and persons. Our study shows that assumed indoor air temperature, internal heat gains and efficiency of ventilation heat recovery units have significant effect on the simulated energy performance of the studied building and energy efficiency measures. Of the considered microclimate parameter values and assumptions, the outdoor temperature, ground solar reflection and window shading have significant impact on the simulated space heating and cooling demands. On the contrary, the simulated energy performances are less affected by the variations in air pressure outside and the percentage of wind load that hits the building. We found that input data and assumptions used for energy balance calculations and energy saving analyses vary significantly in the Swedish context. These result in significantly different calculated final energy performance of buildings and energy efficiency measures. To inform accurate analysis of energy performance of building and energy saving measures, input parameters used in simulation models need to be appropriate.

  • 14.
    Einvall, Jessica
    et al.
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Albertazzi, Simone
    Bologna University, Italy.
    Hulteberg, Christian
    Catator AB.
    Malik, Azhar
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Basile, Francesco
    Bologna University, Italy.
    Larsson, Ann-Charlotte
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Brandin, Jan
    Catator AB.
    Sanati, Mehri
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Investigation of reforming catalyst deactivation by exposure to fly ash from biomass gasification in laboratory scale2007Ingår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 21, nr 5, s. 2481-2488Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Production of synthesis gas by catalytic reforming of product gas from biomass gasification can lead to catalyst deactivation by the exposure to ash compounds present in the flue gas. The impact of fly ash from biomass gasification on reforming catalysts was studied at the laboratory scale. The investigated catalyst was Pt/Rh based, and it was exposed to generated K2SO4 aerosol particles and to aerosol particles produced from the water-soluble part of biomass fly ash, originating from a commercial biomass combustion plant. The noble metal catalyst was also compared with a commercial Ni-based catalyst, exposed to aerosol particles of the same fashion. To investigate the deactivation by aerosol particles, a flow containing submicrometer-size selected aerosol particles was led through the catalyst bed. The particle size of the poison was measured prior to the catalytic reactor system. Fresh and aerosol particle exposed catalysts were characterized using BET surface area, XRPD (X-ray powder diffraction), and H2 chemisorption. The Pt/Rh catalyst was also investigated for activity in the steam methane reforming reaction. It was found that the method to deposit generated aerosol particles on reforming catalysts could be a useful procedure to investigate the impact of different compounds possibly present in the product gas from the gasifier, acting as potential catalyst poisons. The catalytic deactivation procedure by exposure to aerosol particles is somehow similar to what happens in a real plant, when a catalyst bed is located subsequent to a biomass gasifier or a combustion boiler. Using different environments (oxidizing, reducing, steam present, etc.) in the aerosol generation adds further flexibility to the suggested aerosol deactivation method. It is essential to investigate the deactivating effect at the laboratory scale before a full-scale plant is taken into operation to avoid operational problems.

  • 15.
    Gustavsson, Leif
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Truong, Nguyen Le
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Effects of different bioenergy pathways on primary energy efficiency, climate mitigation and energy system integration2015Ingår i: The 10th Conference on Sustainable Development of Energy, Water and Environment Systems – SDEWES 2015. September 27- October 3, 2015, Dubrovnik, Croatia, 2015Konferensbidrag (Refereegranskat)
    Abstract [en]

    Woody biomass is an important renewable energy resource that can be used directly or indirectly in the electricity, heat and transport sectors. Different technologies and conversion pathways can be used to convert woody biomass to supply different types of energy services. The primary energy and climate implications of bioenergy systems depend on which conversion technologies and pathways are used to produce the energy services, as well as how the services would have been supplied without the bioenergy system. Here, we focus on bioenergy for transportation in the context of a total renewable-based energy system. We contrast two different pathways: (i) biomotor fuel production in stand-alone plants and (ii) bioelectricity production in standalone plants and district heating systems with CHP plants and heat storage capacity for electric and plug-in hybrid vehicles. We quantify the primary energy use and the instantaneous biogenic CO2 of the two alternatives, per km of driving distance. We consider both commercially available technologies and emerging technologies for biomass-based conversion systems. Furthermore, for the two alternatives we discuss potential benefits of integration between the electricity, heating and transport sectors, to enable a better use of infrastructure. The results show that primary energy use and instantaneous biogenic CO2 emission vary strongly between the alternatives. The primary energy efficiency is much higher and gives less instantaneous biogenic CO2 emission for electric and plug-in hybrid vehicles compared to vehicles using biomotor fuels. Furthermore, the potential integration benefits between the electricity, heating and transport sectors are much larger due to the integration potential of heat storage capacity in DHS and battery storage capacity in electric and plug-in hybrid vehicles, as well as an improved overall integration capacity between the sectors. This study suggests that use of biomass should be considered in the context of the overall energy system, and in relation to the development of energy conversion technologies and integration potential between different energy sectors, to find primary energy efficient alternatives giving climate benefits in both a short- and long-term perspective.

  • 16.
    Haus, Sylvia
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Climate impact of the sustainable use of forest biomass in energy and material system: a life cycle perspective2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Human society releases greenhouse gas emissions to the atmosphere while providing housing, heat, mobility and industrial production. Man-made greenhouse gas emissions are the main causes of climate change, coming mainly from burning fossil fuels and land-use changes. Sustainably managed forests play an important role in climate change mitigation with the prospect of sustainably providing essential materials and services as part of a low-carbon economy, both through the substitution of fossil-intensive fuels and material and through their potential to capture and store carbon in the long-term perspective.

    The overall aim of this thesis was to develop a methodology under a life cycle perspective to assess the climate impact of the sustainable use of forest biomass in bioenergy and material systems. To perform this kind of analysis a methodological framework is needed to accurately compare the different biological and technological systems with the aim to minimize the net carbon dioxide emissions to the atmosphere and hence the climate impact. In such a comparison, the complete energy supply chains from natural resources to energy end-use services has to be considered and are defined as the system boundaries.

    The results show that increasing biomass production through more intensive forest management or the usage of more productive tree species combined with substitution of non-wood products and fuels can significantly reduce global warming. The biggest single factor causing radiative forcing reduction was using timber to produce wood material to replace energy-intensive construction materials such as concrete and steel. Another very significant factor was replacing fossil fuels with forest residues from forest thinning, harvest, wood processing, and post-use wood products. The fossil fuel that was replaced by forest biomass affected the reductions in greenhouse gas emissions, with carbon-intensive coal being most beneficial to replace. Over the long term, an active and sustainable management of forests, including their use as a source for wood products and bioenergy allows the greatest potential for reducing greenhouse gas emissions.

  • 17.
    Haus, Sylvia
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Gustavsson, Leif
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Sathre, Roger
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Climate mitigation comparison of woody biomass systems with the inclusion of land-use in the reference fossil system2014Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 65, s. 136-144Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    While issues of land-use have been considered in many direct analyses of biomass systems, little attention has heretofore been paid to land-use in reference fossil systems. Here we address this limitation by comparing forest biomass systems to reference fossil systems with explicit consideration of land-use in both systems. We estimate and compare the time profiles of greenhouse gas (GHG) emission and cumulative radiative forcing (CRF) of woody biomass systems and reference fossil systems. A life cycle perspective is used that includes all significant elements of both systems, including GHG emissions along the full material and energy chains. We consider the growth dynamics of forests under different management regimes, as well as energy and material substitution effects of harvested biomass. We determine the annual net emissions of CO2, N2O and CH4 for each system over a 240-year period, and then calculate time profiles of cRF as a proxy measurement of climate change impact. The results show greatest potential for climate change mitigation when intensive forest management is applied in the woody biomass system. This methodological framework provides a tool to help determine optimal strategies for managing forests so as to minimize climate change impacts. The inclusion of land-use in the reference system improves the accuracy of quantitative projections of climate benefits of biomass-based systems. (c) 2014 Elsevier Ltd. All rights reserved.

  • 18.
    Haus, Sylvia
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Gustavsson, Leif
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Sathre, Roger
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Greenhouse Gas Emission Comparison of Woody Biomass Systems with the Inclusion of Land-use in the Reference Fossil System2013Ingår i: 21st European Biomass Conference & Exhibition, Copenhagen, June 3-7, 2013, ETA-Florence Renewable Energies, , 2013, s. 1794-1799Konferensbidrag (Refereegranskat)
    Abstract [en]

    While issues of land-use have been considered in many analyses of biomass systems, little attention has heretofore been paid to land-use in reference fossil systems. In this study we address this limitation by comparing forest biomass systems to reference fossil systems with explicit consideration of land-use in both systems. We estimate and compare the time profiles of greenhouse gas (GHG) emission and cumulative radiative forcing (CRF) of woody biomass systems and reference fossil systems. A life cycle perspective is used that includes all elements of both systems and all GHG emissions along the full material and energy chains. We consider the growth dynamics of forests under different management regimes, as well as energy and material substitution effects. We determine the annual net emissions of CO2, N2O and CH4 for each system over a 240-year period. We then calculate time profiles of CRF as a proxy for climate change impacts. The results show greatest CRF reduction when fertilized forest management is applied in the woody biomass system. The results show the relevance of including land use options in both the biomass and the fossil system to accurately determine the climate impacts and benefits of forest management and product use.

  • 19.
    Hemström, Kerstin
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Gustavsson, Leif
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Mahapatra, Krushna
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Contractor Perceptions of Very Energy Efficient New Multi-Story Residential Buildings2014Ingår i: World Sustainable Building 2014 Barcelona Conference: Sustainable Buildings: Results ; Are We Moving as Quickly as We Should? It's Up to Us!, GBCe , 2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    To facilitate design of policies and strategies which aim to promote a sustainable development of the built environment, a deeper understanding of factors influencing the decisions taken in construction projects is needed. This study investigates Swedish contractors’ perceptions of the new-build of very energy efficiency multi-storey residential buildings (e.g. passive houses). The results of interviews with twenty selected contracts managers disclose several perceived disadvantages and risks associated with such buildings which influence the interest to invest in high energy efficiency. These include several cost and market-related issues as well as issues relating to the performance of the buildings. Without market intervention it seems unlikely that very energy efficient multi-storey residential buildings will diffuse to any substantial degree within the Swedish construction industry.

  • 20.
    Hemström, Kerstin
    et al.
    Mittuniversitetet.
    Mahapatra, Krushna
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Gustavsson, Leif
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Swedish private forest owners’ perceptions and intentions with respect to adopting exotic tree species2013Ingår i: European Journal of Forest Research, ISSN 1612-4669, E-ISSN 1612-4677, Vol. 132, nr 3, s. 433-444Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Swedish forest growth can be increased through intensive forestry practices, enabling an increased use of forest biomass for climate-change mitigation. However, the diffusion of such practices depends on the forest owners’ adoption of them. We study Swedish private forest owners’ perceptions and intentions with respect to increasing forest growth by adopting exotic tree species. The results of a mail-in questionnaire survey show that although a majority of forest owners desire increasing forest growth, most owners have only a basic understanding of exotic tree species and a smaller proportion is interested in adopting them. The intention to adopt exotics seems to depend on the perceived performance of the species with respect to the economic aspects of forest management rather than on environmental or recreational concerns. Whereas a knowledge gap among the private forest owners regarding how to increase forest growth is implied, forest owners with higher self-rated knowledge of forestry and exotics have stronger intentions to adopt such species.

  • 21.
    Hjort, Åke
    et al.
    Euronom AB.
    Carlsson, Bo
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Method and Device for heating a building using a solar collector2014Patent (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    Method when heating a building with solar collectors comprising also a heat pump and energy storage using phase change materials. The invention is charaterized in that the energy storage system comprises to two containers, one placed indoors, where the phase change material has a melting point between 19 and 30 degrees Celsius, and a second container located outdoors and buried in the ground, where the phase change material has a conversion temperature which corresponds to or is lower  than the mean temperature of the ground surrounding the container.

  • 22.
    Joelsson, Jonas
    et al.
    Mittuniversitetet.
    Gustavsson, Leif
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Reductions in greenhouse gas emissions and oil use by DME (di-methyl ether) and FT Fischer-Tropsch) diesel production in chemical pulp mills2012Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 39, nr 1, s. 363-374Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Using energy systems analysis, we examine the potential to reduce CO2 emissions and oil use by integrating motor biofuel production with pulp mills. BLG-DME (black liquor gasification with di-methyl ether production) is compared with solid biomass gasification with BIG-Fr (solid biomass gasification with Fischer-Tropsch fuel production). The studied systems are expanded with stand-alone production of biomass-based electricity and motor fuel so that they yield the same functional unit in terms of motor fuel and electricity as well as pulp or paper product, in order to facilitate comparison. More motor biofuel can be produced in integration with the studied mills with BLG-DME than with BIG-FT because the black liquor flow is large compared with other fuel streams in the mill and the integration potential for BIG-FT is limited by the mill's heat demand. When both systems are required to produce the same functional unit, the BLG-DME system achieves higher system efficiency and larger reductions in CO2 emissions and oil use per unit of biomass consumed. In general, integration of motor biofuel production with a pulp mill is more efficient than stand-alone motor biofuel production. Larger reductions in CO2 emissions or oil use can, however, be achieved if biomass replaces coal or oil in stationary applications.

  • 23.
    Joelsson, Jonas
    et al.
    Mittuniversitetet.
    Gustavsson, Leif
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Swedish biomass strategies to reduce CO2 emission and oil use in an EU context2012Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 43, nr 1, s. 448-468Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Swedish energy strategies for transportation, space heating and pulp industries were evaluated with a focus on bioenergy use. The aims were to 1) study trade-offs between reductions in CO2 emission and oil use and between Swedish reductions and EU reductions, 2) compare the potential contributions of individual reduction measures, 3) quantify the total CO2 emission and oil use reduction potentials. Swedish energy efficiency measures reduced EU CO2 emission by 45-59 Mt CO2/a, at current biomass use and constant oil use. Doubling Swedish bioenergy use yielded an additional 40 Mt CO2/a reduction. Oil use could be reduced, but 36-81 kt of reductions in CO2 emission would be lost per Pi of oil use reduction. Swedish fossil fuel use within the studied sectors could be nearly eliminated. The expansion of district heating and cogeneration of heat with a high electricity yield were important measures. Plug-in hybrid electric cars reduced CO2 emission compared with conventional cars, and the difference was larger with increasing oil scarcity. The introduction of black liquor gasification in pulp mills also gave large CO2 emission reduction. Motor fuel from biomass was found to be a feasible option when coal is the marginal fuel for fossil motor fuel production. (C) 2012 Elsevier Ltd. All rights reserved.

  • 24.
    Johansson, Kristian
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Gustafsson, Filip
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Analys av förluster i småskaligt fjärrvärmenät: En studie för Lessebo Fjärrvärme2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Denna studie analyserar de rapporterat höga förlusterna i ett småskaligt fjärrvärmenät i Lessebo där styrkort för år 2013 redovisar förluster på 38 %. Genom att med en kvantitativ metod beräkna de värmeförluster som sker genom värmeledning i rörnätet görs en bedömning om rörnätets utformning är källan till de höga förlusterna eller ej. Studien ger indikationer på att fjärrvärmenätet i Lessebo är bra utformat och det därför finns oidentifierade orsaker till de höga förlusterna. Utöver redogörande av värmeförluster ger rapporten även kunskaper om fjärrvärmebranschens flera tekniker, begränsningar och framtida utvecklingsmöjligheter.

  • 25.
    Lin, Leteng
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Morgalla, Mario
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Strand, Michael
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Study on char fragmentation during biomass gasification in bubbling fluidized bed2015Ingår i: 23rd European Biomass Conference and Exhibition, 1-4 June 2015, Vienna, Austria, ETA-Florence Renewable Energies , 2015, s. 652-655Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this work a bench scale bubbling fluidized bed gasifier was built to work with an aerosol sampling and measuring system in order to study char fragmentation phenomenon during biomass gasification process. Both barbeque char and wood pellets were gasified in CO2 (20 vol.%) -N2 mixture and steam (30 vol.%)-N2 mixture, respectively. An aerodynamic particle sizer (APS) was used to measure fragmented char particles during the whole gasification process. For the wood pellet gasification case, major fragmentation was observed during the devolatilization stage, which should be attributed to the combined effect of primary fragmentation and attrition. The aerodynamic diameter of those elutriable particles which can be measured by the current system was in the range of 0.5-8 µm. During the char gasification stage, a distinct mode of char fragments was produced in the size range of 1-7 µm in either case. The total mass concentration of elutriable particles gradually increased when gasification of char started, and then decreased while the reaction approached completion.

  • 26.
    Lin, Leteng
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Strand, Michael
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Further development and application of aerosol-based method for on-line investigation of char reactivity in steam2013Ingår i: Proceedings for 21st European Biomass Conference and Exhibition, ETA-Florence Renewable Energies , 2013, s. 875-878Konferensbidrag (Refereegranskat)
    Abstract [en]

    Wood char was prepared from wood pellets under controlled pyrolysis conditions. The gasification kinetics for wood char in 33 vol% steam was established in the temperature range from 800ºC to 1300ºC by the combination of thermogravimetric analysis (TGA) and a novel aerosol-based method. The aerosol method was further developed and demonstrated successfully for generating, transporting and gasifying the suspended char particles (0.5-10 µm) in the steam atmosphere at high temperature up to 1300ºC. A tapered element oscillating microbalance (TEOM) was used to measure the change of mass concentrations of particles in the carrier gas, before and after gasification. The activation energy was 155 kJ·mol-1 for wood char with the pre-exponential factor of 3.56×104. This method can be potentially applied to on-line measure the reactivity of char particles directly in hot gas from the gasifier.

  • 27.
    Lindberg, Marcus
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Sjöfartshögskolan (SJÖ).
    Johansson, Per
    Linnéuniversitetet, Fakulteten för teknik (FTK), Sjöfartshögskolan (SJÖ).
    Joélius, Mikael
    Linnéuniversitetet, Fakulteten för teknik (FTK), Sjöfartshögskolan (SJÖ).
    LNG - Framtidens fartygsbränsle: Vad är det som hämmar utvecklingen av LNG-drift i Sverige?2015Självständigt arbete på avancerad nivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Sjöfarten står idag inför allt strängare miljökrav. För att uppnå miljövänligare resultat har allt fler rederier börjat se sig om efter ett miljövänligare bränsle. Östersjön är ett stort handelsområde där striktare krav från SECA träder i kraft den 1 januari 2015. Fartyg med LNG-drift diskuteras flitigt som ett alternativt bränsle inom den svenska sjöfartsnärningen, då utsläppen av NOx, svavel och partiklar är mindre än tjockoljan (HFO). Ett av problemen med LNG i Sverige är att det i dagsläget inte finns ett tillräckligt utvecklat infrastrukturnät för flytande naturgas. I denna rapport har vi med hjälp av kvalitativa intervjuer kartlagt svenska aktörer inom LNGs infrastrukturutveckling och vad det är som hämmar utvecklingen.

    Vår analys av intervjuerna visade att utvecklingen bromsades av att ingen vågat ta första steget. Hamnarna vill inte bygga terminaler om det inte finns en marknad för distribution och rederierna vill inte bygga fartyg om det inte finns tillgänglighet av LNG. Det har också framkommit att intresset från den svenska staten har varit mycket svagt, näst intill obefintligt. Det finns även en del tomrum i de svenska regelverken kring hanteringen av LNG, vilket är en av faktorerna till att LNGs utveckling hämmas. 

  • 28.
    Mainali, Brijesh
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET). KTH Royal Institute of Technology.
    Ahmed, Hassan
    KTH Royal Institute of Technology.
    Silveira, Semida
    KTH Royal Institute of Technology.
    Integrated approach for provision of clean energy and water in rural Bangladesh2018Ingår i: Ground Water for Sustainable Development, ISSN 2352-801X, Vol. 7, s. 239-249Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ultimate goal of this paper is to explore ways to upgrade energy and water services in rural areas of Bangladesh while improving resource recovery. The study analyzes the potential of a poly-generation system using locally available biomass resources (cow dung and agriculture residue) for providing cooking energy, electricity, and drinking water to a rural community. A questionnaire survey was conducted in Pani Para village with 52 households to investigate demand patterns and estimate the resource potential and amount of biogasneeded in the poly-generation system. A poly-generation system with 150 m3biogas digester and a 10 kWe generator is required to meet cooking energy, electricity and water demand in the village. Co-digestion of available resources including cow dung and agriculture residues can provide 48,250 m3 biogas/year, which is sufficient to supply electricity and clean drinking water to all households in the village. In addition, around two thirds of the households can use biogas for cooking. The sensitivity analysis shows that if the amount of agriculture residues is increased by 15%, also cooking gas can be provided to all households. The results indicate that such integrated solutions are worth further exploration.

  • 29.
    Mainali, Brijesh
    et al.
    Royal Institute of Technology.
    Emran, Saad Been
    Royal Institute of Technology.
    Silveira, Semida
    Royal Institute of Technology.
    Greenhouse gas mitigation using poultry litter management techniques in Bangladesh2017Ingår i: Energy Journal, ISSN 0195-6574, E-ISSN 1944-9089, Vol. 127, s. 155-166Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Poultry activities have expanded significantly in Bangladesh in recent years. The litter generated from rural poultry farms is often dumped in low ground neighboring areas resulting in greenhouse gas emissions, as well as water and air pollution. This study estimates the GHG emissions of a typical rural layer poultry farm in Bangladesh, and identifies the GHG emissions reduction potential when poultry litter management techniques are used to produce biogas, generating electricity and bio-fertilizer. Life-cycle assessment (LCA) has been used for a systematic evaluation of GHG-emissions considering the local supply chain in a typical rural layer poultry farm. The analysis shows that the GHG-emissions at the poultry farm amount to 1735 KgCO2eq/10000 eggs produced if the litter is untreated. With the installation of an anaerobic digester, the emission intensity could be reduced by 65% if the gas is used to replace LPG for cooking purposes. If 100% digested slurry is utilized as bio-fertilizer, the emissions intensity could be further reduced by 17 times compared to the case without slurry utilization. These results justify the consideration of national programs to improve conditions in poultry farms in Bangladesh. 

  • 30.
    Mainali, Brijesh
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET). KTH Royal Institute of Technology.
    Luukkanen, Jyrki
    University of Turku, Finland.
    Silveira, Semida
    KTH-Royal Institute of Technology.
    Kaivo-oja, Jari
    University of Turku, Finland.
    Evaluating Synergies and Trade-Offs among Sustainable Development Goals (SDGs): Explorative Analyses of Development Paths in South Asia and Sub-Saharan Africa2018Ingår i: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 10, nr 3, artikel-id 815Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Understanding the linkages between multiple targets of Sustainable Development Goals(SDGs) may help to integrate different sectoral programmes and develop coherent cross-sectoralpolicy to explore synergies. Synergy is interaction among two or more actions, which will lead toan impact greater or less than the sum of individual effects. Therefore, synergy can be positive ornegative (trade-off). This paper aims at developing an analytical framework to evaluate sectorallinkages and examine potential synergies and trade-offs among various SDGs’ goals and targets.Synergies and trade-offs related to energy access (SDG7), clean water and sanitation access (SDG6),food security and sustainable agriculture (SDG2) and poverty alleviation (SDG1) have been evaluatedfrom the perspective of developing countries using examples from South Asia (Bangladesh, Nepal,and Sri Lanka) and Sub-Saharan Africa (Ghana, Ethiopia and Rwanda), and historical data for theperiod between 1990 and 2012. The analytical framework includes both qualitative and quantitativemethods. Network analysis technique has been used for exploring the conceptual linkage amongdifferent indicators, and capturing the targets associated with SDGs. Advanced SustainabilityAnalysis (ASA) developed under the European framework programme has been used for quantifyingthe synergies and trade-offs among sustainability indicators. The analysis showed strong synergyamong various SDG targets. Interestingly, the potential synergy differs from country to countryand over time. Ghana and Sri Lanka had relatively higher potential synergy, whereas Rwanda andNepal had relatively lower potential synergy among the various targets. Higher synergy valueswere evidenced in those cases where the policy have recognized and emphasized on linkages amongcross-sectoral targets.

  • 31.
    Mainali, Brijesh
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Mahapatra, Krushna
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Pardalis, Georgios
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Evaluating market models for deep-energy renovation using SWOT and PEST Analysis2018Ingår i: 14th Conference on Advanced Building Skins, 28-29 October, 2018, Bern, Switzerland, 2018Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Buildings are responsible for 40% of energy consumption and 36% of CO2 emissions in the EU. Sweden and Denmark are cold climatic countries with strong demand for space heating and hot water in the residential sector. Large section of the detached houses in these countries are built more than 30 years ago and need refurbishment. Despite of huge energy saving potentials with deep renovation of these houses, there exists several challenges in realizing those saving potential. This paper evaluates the market for deep renovation of single-family houses in these two Nordic countries using PEST and SWOT analysis. Comparative analysis between two countries will help to understand the common and country specific drivers and barriers and to develop strategic recommendation in accordance.

  • 32.
    Mainali, Brijesh
    et al.
    KTH Royal Institute of Technology, Sweden.
    Pachauri, Shonali
    International Institute for Applied Systems Analysis, Austria.
    Rao, Narasimha D.
    International Institute for Applied Systems Analysis, Austria.
    Silveira, Semida
    KTH Royal Institute of Technology, Sweden.
    Assessing rural energy sustainability in developing countries2014Ingår i: Energy for Sustainable Development, ISSN 0973-0826, Vol. 19, s. 15-28Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Providing sustainable energy access is one of the most critical global challenges. This paper introduces a method for evaluating the status and progress of rural household energy sustainability in developing countries using a new composite indicator, the energy sustainability index (ESI). The ESI combines 13 techno-economic, environmental and social indicators of sustainability using principal component analysis (PCA). We apply the ES! to China, India, South Africa, Sri-Lanka, Bangladesh and Ghana between 1990 and 2010. The analysis suggests that South Africa's rural energy sustainability index is highest followed by China, Sri Lanka, India, Bangladesh and Ghana respectively. All the countries' rural energy sustainability has improved relatively over time except Ghana's. Improvements result mainly from increasing rural electricity use and increasing access to clean and efficient cooking fuels.

  • 33.
    Mainali, Brijesh
    et al.
    KTH Royal Instute of Technology.
    Silveira, Semida
    KTH Royal Instute of Technology.
    Alternative pathways for providing access to electricity in developing countries2013Ingår i: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 57, s. 299-310Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The discussion on electrification pathways tends to dangle between the merits of centralized on-grid versus decentralized off-grid electrification, and most of the time, both routes are promoted in parallel. However, the basis for choosing pathways has neither been very clear nor rational. This study compares three pathways for rural electrification considering (i) off-grid renewable energy (RE) technologies for individual households (ii) mini grids (with micro hydro and diesel generators) and (iii) grid extension. Different technological pathways are analyzed considering various technical and socio-economic parameters in two country cases: Nepal and Afghanistan. Levelized cost of electricity (LCOE) is taken as the main basis for comparison of the various options, in which both environmental externalities and life cycle costs are considered. The analysis shows that the micro hydro based mini grid technology is the most competitive alternative for electrifying isolated and remote rural areas in both countries. Individual household technology should be promoted only in places with scattered households where there is no possibility of mini grid solution. The choice of technology and the pathway adopted in Nepal seems functional, though some flaws within the pathways need to be addressed. In Afghanistan, the technological pathways for rural electrification are not well-defined and the country lacks a clear cut national policy framework for rural electrification. Here, micro hydro based mini grid would be a more sustainable proposition rather than diesel generators as promoted in the transitional phase. Afghanistan can benefit from lessons learnt in Nepal not least in the formation of markets for renewable technologies.

  • 34.
    Mainali, Brijesh
    et al.
    Royal Institute of Technology, Sweden.
    Silveira, Semida
    Royal Institute of Technology, Sweden.
    Financing off-grid rural electrification: Country case Nepal2011Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 36, nr 4, s. 2194-2201Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    More than 61% of the total population of Nepal has no access to electricity. The majority is poor and live in rural areas. In recent years, rural electrification has had high priority in government policies, and micro hydro and solar PV have been the most commonly adopted off-grid technologies. The financial mix in the off-grid rural electrification is generally characterized by subsidy, equity and credit. In this paper, we analyze how rural electrification has been funded and the impact of subsidy policies on the renewable energy market, focusing on the projects implemented under the ‘subsidy policy 2000’. Our study is based on official data obtained from authorities in Nepal and a survey carried out among private supply and installation companies, NGOs and financial institutions. The study shows that awareness levels in adopting RE-technologies and willingness of people to access and pay for electricity have increased significantly. However, there is a huge financial gap between the cost of electrification and the affordability. Bridging this gap is a crucial issue that needs to be addressed for the smooth expansion of rural electrification in the country.

  • 35.
    Mainali, Brijesh
    et al.
    Royal Institute of Technology, Sweden.
    Silveira, Semida
    Royal Institute of Technology, Sweden.
    Renewable Energy Market in Rural Electrification: Country Case Nepal2012Ingår i: Energy for Sustainable Development, ISSN 0973-0826, Vol. 16, nr 2, s. 168-178Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Markets for Renewable Energy (RE) technologies are emerging in Nepal in connection with rural electrification in the country. Two promising technologies are in evidence – solar home system (SHS) and micro-hydro. The availability of abundant renewable resources, lack of fossil fuels and difficult geographical terrain for grid line extensions contribute to the advantages of RE based decentralized rural electrification in Nepal. The distributional analysis shows increase in extensive growth and decrease in the intensive growth rate of rural electrification thus indicating market expansion with uneven penetration among the rural people. Solar PV technology is still not in the reach of the economic poor. This paper discusses and analyzes RE based rural electrification supply models, economics behind rural electrification, market drivers and market distribution in the rural areas of Nepal. Access to credit and cumbersome subsidy delivery mechanism have been perceived as the major factors affecting the expansion of rural electrification by the stakeholders, requiring innovations in credit and subsidy delivery system so that a larger rural population can have access to electrification.

  • 36.
    Mainali, Brijesh
    et al.
    KTH Royal Instute of Technology.
    Silveira, Semida
    KTH Royal Instute of Technology.
    Using a sustainability index to assess energy technologies for rural electrification2015Ingår i: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 41, s. 1351-1365Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper introduces a method for evaluating the sustainability performance of energy technologies applied in rural electrification, using the multivariate technique called Principal component analysis (PCA).The sustainability is assessed in terms of energy technology sustainability index (ETSI). The ETSI has been used for assessing the sustainability performance of ten different energy systems in the case of India. Since this method is static in nature, the sustainability performance analysis is made for three different years (2005, 2010 and 2015) to capture technological advancements and changes in market conditions for the various technologies over time. The result shows that mature technologies such as biomass gasifiers, biogas and microhydro technologies have relatively better sustainability performance among the options analyzed. There is slight increment in their sustainability performance in the ten year period considered. Emerging technologies such as solar and wind have fairly good improvement in the sustainability performance over the studied time but still have difficulties competing with the mature technologies and conventional technologies without policy support. Analysis has been made with probable, minimum and maximum capital costs, operational and fuel costs to capture uncertainty among the input assumptions, and sensitivity has been reflected in the analysis of energy technology sustainability index (ETSI). This ETSI could help improve energy technology assessments, particularly when it comes to the feasibility of available alternatives.

  • 37.
    Morgalla, Mario
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Lin, Leteng
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Strand, Michael
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Characterization Of Particulate Matter In Biomass Gasification2015Ingår i: Proceedings for the 23rd European Biomass Conference and Exhibition / [ed] I. Obernberger, D. Baxter, A.Grassi, P.Helm, ETA-Florence Renewable Energies , 2015, s. 664-667Konferensbidrag (Refereegranskat)
    Abstract [en]

    The purpose of this work is to examine the potential of monitoring heavy tar compounds contained in the product gas of a biomass gasifier. The hot product gas from atmospheric indirect bubbling fluidized bed gasification of wood pellets was extracted. The sampling and conditioning system consisted of a high-temperature dilution probe, a primary thermodenuder and a secondary thermodenuder. Online and semi-online instruments were used to characterize the aerosol in terms of number size distribution and particle mass concentration. The fine mode (mobility equivalent diameter db < 150 nm) was found to mainly consist of heavy tar compounds. An Electrical low­pressure impactor (ELPI) was used to measure this mode with a time resolution of 1 second and thus showed the potential for online measurements of heavy tar.

  • 38.
    Munkacsi, Noemi
    et al.
    Budapest University of Technology and Economics, Hungary.
    Mahapatra, Krushna
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Communication and Household Adoption of Heating Products in Hungary2019Ingår i: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, nr 2, s. 1-22, artikel-id 305Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Existing studies of heating products have analyzed the adoption of energy-efficient heating technologies from diverse micro and macroeconomic aspects, such as diffusion of innovation, willingness to pay, business models, energy pricing, etc., but the analysis from a marketing management approach based on end customer insight is still lacking. Understanding the decision-making process of end customers, and the influence of social environment at the diverse stages of the purchase process leads to a focused market strategy, thereby contributes toward overcoming the multi-level segmentation challenge faced by the manufacturers of heating products. In this context, a two-step exploratory research was conducted in December 2013 with end customers of the residential heat market in Hungary. The end customers were found to be active decision-makers engaged in deliberate planning in the purchase of heating products. They start searching for information by turning mainly to online information sources and they actively integrate their social network in all stages of the decision-making process, which means that the role of the installer is relatively less influential along the whole purchasing process. Identified influencing communication channels at the diverse stages of the purchase process may support manufacturers to develop a user-centric marketing strategy by optimizing the communication instruments in their marketing mix by, for instance, including direct end customer communication via online channels and by de-emphasizing offline communication channels.

  • 39.
    Munkacsi, Noemi
    et al.
    Budapest University of Technology and Economics, Hungary.
    Mahapatra, Krushna
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    The role of social influence in the end customer purchasing decisions on the heat market2017Ingår i: Proceedings from eceee Summer Studies, European Council for an Energy Efficient Economy (ECEEE), 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this paper is to examine the role of social influence on the end customer behaviour in the purchase of heating products in residential segment. The study is based on interviews and questionnaire survey of homeowners in Hungary in 2013. Respondents are open to learn about diverse innovative heating technologies, energy types and diverse heating fuels irrespective of any purchase intention. They plan their purchase based on deliberate considerations rather than facing an emergency heating appliance breakdown. Furthermore, influence of the social environment prevails at the diverse stages of the purchase process. End customers actively conduct social search (family, friends, neighbours, colleagues, other customers with purchase experience over the Internet, etc.) besides the influencing role of the installer.

  • 40.
    Nilsson, Bengt
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Nilsson, Daniel
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Thörnqvist, Thomas
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Distribution of logging residues at the clear-felled site after fuel adapted logging operations2015Ingår i: Papers of the 23rd European Biomass Conference: Setting the course for a biobased economyExtracted from the Proceedings of the International Conference held in Viennna, Asutria1-4 June 2015 / [ed] Obernberger I, Baxter D, Grassi A, Helm P, ETA-Florence Renewable Energies , 2015, s. 270-272Konferensbidrag (Refereegranskat)
    Abstract [en]

    During extraction of logging residues previous studies in Sweden have shown that up to 50% of the available logging residues will not reach the energy-conversion site. The remaining potential of the logging residues are therefore lost by handling either at the clear-felled site, during transportation or due to decomposition. An outtake of 100% is not possible or desired, since the Swedish Forest Agency recommends that at least 20% of the logging residues should be left at the clear-felled site after a fuel adapted logging operation. In this study the losses at the clear-felled area is examined by studying the distribution of the remaining logging residues under and between the harvester heaps as well amount of logging residues that are left at the roadside landing after comminution. The results show that most of the reaming logging residues are well distributed at the clear-felled area between the harvester heaps. Additional logging residues are left at the clear-felled area since the forwarder cannot gather all logging residues from under the harvester heaps. In addition to this a not insignificant amount of logging residues are left at the roadside landing.

  • 41.
    Nilsson, Bengt
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Nilsson, Daniel
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Thörnqvist, Thomas
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Distributions and Losses of Logging Residues at Clear-Felled Areas during Extraction for Bioenergy: Comparing Dried- and Fresh-Stacked Method2015Ingår i: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 6, nr 11, s. 4212-4227Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is well known that a large proportion of available logging residues intended for extraction will not reach the energy-conversion industry, because some are lost during transportation or left on the clear-felled area. However, there is little understanding of where logging residue losses occur in the supply chain. In this study, the distribution of logging residues for two methods (dried- and fresh-stacked method) to extract logging residues were studied in one clear-felled area. In addition, residue fractions were examined in a detailed comparison. Even though the fresh-stacked method left somewhat more logging residues at the clear-felled area, the differences are small between the methods. Approximately 30% of the total amount of logging residues was left behind between the harvester heaps, with an additional 10%-15% under these heaps and approximately 2%-3% beneath the windrows. The final product that was delivered to the energy-conversion industry was very similar, regardless of the extraction method used. The delivered chipped logging residues had moisture contents of 37% and 36% following fresh- and dried-stacked methods respectively, and in both cases the needle content in the processed logging residues was approximately 10%. However, the total amount of fine fractions (needles and fines) was slightly higher following dried-stacking.

  • 42.
    Nilsson, Daniel
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Nilsson, Bengt
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Thörnqvist, Thomas
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Nutrient removal after whole-tree harvesting with the traditional Swedish dried-stacked method for removal of logging residues2015Ingår i: Papers of the 23rd European Biomass Conference: Setting the course for a biobased economyExtracted from the Proceedings of the International Conference held in Viennna, Asutria1-4 June 2015 / [ed] Obernberger I, Baxter D, Grassi A, Helm P, ETA-Florence Renewable Energies , 2015, s. 9-13Konferensbidrag (Refereegranskat)
    Abstract [en]

    Bioenergy from logging residues is an important contributor to Swedish energy supplies. Logging residues where long defined and regarded as the unmerchantable aboveground biomass left behind in the clear-felled area, consisting of branches, tops and small trees that are gathered after the round wood harvest, but logging residues are nowadays regarded as a third assortment next to timber and pulpwood with high economic value. However long-term experiments on removal of logging residues from Norway spruce (Picea abies (L.)Karst) stands have shown both growth reductions and growth increase in the next generation, because of decreasing amounts of nutrients. So an increased removal of logging residues requires some sort of compensation of nutrients. Therefore it is of importance to investigate how much nutrients that is removed from the stand after whole-tree harvesting.

    In this study the removal of the nutrients nitrogen (N), phosphorus (P), calcium (Ca), potassium (K) and magnesium (Mg) have been investigated by laboratory analysis of the nutrients together with the actual removal of stemwood, bark and logging residues. The study has also investigated the distribution of nutrients at the clear-felled area.

    The results show that approximately half of the total nutrient removed in whole tree harvesting is done with the removal of stemwood and bark. The results also show that approximately 30% of the total amount of nutrients is left at the clear-felled area.

  • 43.
    Paulrud, Susanne
    et al.
    Research Institutes of Sweden (RISE).
    Gustavsson, Lennart
    Research Institutes of Sweden (RISE).
    Johansson, Jimmy
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Tekniska och ekonomiska förutsättningar för oljeersättning i industrin med pyrolysolja2017Övrigt (Övrigt vetenskapligt)
  • 44.
    Persson, Helena
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Carlsson, Bo
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Perers, Bengt
    DTU.
    Development and validation of a TRNSYS/TRNSED-software for combi-heating systems2013Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    There is a need for accurate and readily available information about theoptimization, economics, and environmental impacts of combi-heating systems.Accordingly, the authors have developed TRNSYS-based software called Flexifuel thatincludes a TRNSED application for calculating the annual system performance ofcombi-heating systems involving any combination of heat pumps, flat or vacuumtube solar collectors, pellet burners, electric auxiliary heaters, and heatstorage tanks. Selection of less complex software systems and types reduces thesimulation time without significantly affecting the accuracy of the results.Annual performance data for a system can be simulated in from one to twominutes. Comparison of accumulated theoretical and measured performance dataover the time period for a full-scale test plant with heat pumps and solarcollectors showed that simulation errors were below 5%.

  • 45.
    Persson, Helena
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Perers, Bengt
    DTU.
    Carlsson, Bo
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Type12 and Type56: a load structure comparison in TRNSYS2011Konferensbidrag (Refereegranskat)
  • 46.
    Poudel, Bishnu Chandra
    et al.
    Mid Sweden University.
    Sathre, Roger
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Bergh, Johan
    SLU, Alnarp.
    Gustavsson, Leif
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
    Lundström, Anders
    Hyvonen, Ritta
    Potential effects of intensive forestry on biomass production and total carbon balance in north-central Sweden2012Ingår i: Environmental Science and Policy, ISSN 1462-9011, E-ISSN 1873-6416, Vol. 15, nr 1, s. 106-124Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We quantify the potential effects of intensive forest management activities on forest production in north-central Sweden over the next 100 years, and calculate the potential climate change mitigation feedback effect due to the resulting increased carbon stock and increased use of forest products. We analyze and compare four different forest management scenarios (Reference, Environment, Production, and Maximum), all of which include the expected effects of climate change based on SRES B2 scenario. Forest management practices are intensified in Production scenario, and further intensified in Maximum scenario. Four different models, BIOMASS, HUGIN, Q-model, and Substitution model, were used to quantify net primary production, forest production and harvest potential, soil carbon, and biomass substitution of fossil fuels and non-wood materials, respectively. After integrating the models, our results show that intensive forestry may increase forest production by up to 26% and annual harvest by up to 19%, compared to the Reference scenario. The greatest single effect on the carbon balance is from using increased biomass production to substitute for fossil fuels and energy intensive materials. Carbon stocks in living tree biomass, forest soil and wood products also increase. In total, a net carbon emission reduction of up to 132 Tg (for Maximum scenario) is possible during the next 100 years due to intensive forest management in two Swedish counties, Jamtland and Vasternorrland

  • 47.
    Razmjoo, Narges
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Hermansson, Sven
    Strand, Michael
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Characterization of the fuel bed combustion of wood residues in a 4 MW grate boiler2015Ingår i: European Biomass Conference and Exhibition Proceedings, 2015, s. 741-744Konferensbidrag (Refereegranskat)
    Abstract [en]

    Information about distributions of temperature and gas species within the fuel bed is of great importance in studying the formation of pollutants in an industrial-scale biomass boiler. The main objective of this study was to investigate the gas composition and temperature in some available sections of the fuel bed of a 4 MW reciprocating grate boiler, burning mixture of fresh pine wood chips, bark, and sawdust with two significantly different moisture content levels. The averageCO, CO2,CH4, and O2 concentrations measured during the combustion of the more moist fuel (about 60 mass %) were about 12, 12, 2, and 4 vol. %, respectively, whereas the corresponding values for the less moist fuel (about 45 mass %) were about15, 10, 2.5, and 5 vol. %, respectively. Higher concentration of CO and lower concentration of CO2 for the less moist fuel could originate either from the char conversion process or from the reactions of the devolatilizationgas products.

  • 48.
    Razmjoo, Narges
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Strand, Michael
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    In-bed combustion charachteristics of wet wood chips and sawdust in a full-scale grate boiler2017Ingår i: Proceedings 13th International Conference on Energy for a Clean Environment, 2017Konferensbidrag (Refereegranskat)
  • 49.
    Rehnström, Johan
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Sjöfartshögskolan (SJÖ).
    Isak, Undestam
    Linnéuniversitetet, Fakulteten för teknik (FTK), Sjöfartshögskolan (SJÖ).
    Effektivisering av kylmedelskylare på Nybro Energis kraftvärmeverk.: Bibehållen kyleffekt även vid höga omgivningstemperaturer för full effekt på pannan utan att överstrida befintlig ljudnivå. Minskning av elförbrukning.2018Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Avfallseldade kraftvärmeverk får idag betalt för att ta emot och elda avfall. Dessa intäkter är ofta högre än intäkterna från elproduktion och värmeproduktion så man vill under de flesta förhållanden elda så mycket som det är möjligt. För att göra sig av överskottseffekten som kan uppstå kyler man bort det man inte behöver.

    Nybro Energis kraftvärmeverk i Transtorp använder sig utav 6 stycken kylpaket med 4 fläktar på varje för att kunna kyla bort denna överskottseffekt. Vid installeringen var målsättningen att kunna kyla bort 10MW men det visade sig att under sommaren när utomhustemperaturen blev högre kunde kyleffekten gå ner till 7MW.

    Vår undersöknings syfte var att med en ny motor med ett högre cos α göra tester på en av fläktarna och se om man kan öka kyleffekten och få ner förbrukningen på motorerna utan att kylpaketen ska ge ifrån sig högre ljudnivåer än tidigare.

    Ett alternativ till att enbart sänka strömförbrukningen för den befintliga motorn är att faskompensera och det framgick att elförbrukningen gick att sänka från 8.2A till 3.88A.

    Det framgick att den nya motorn när den frekvensstyrs på 40hz drar högre aktiv effekt men avsevärt mindre reaktiv effekt som gör den billigare i drift. Under mätningarna för att få fram kyleffekten uppmättes tvivelaktiga värden som visade att den kylde sämre på 40hz än den tidigare motorn trots ett högre varvtal. Detta stämmer inte teoretiskt och det är orimligt att den inte kommer kyla. På 40hz kommer den nya motorn även att ge ifrån sig mindre ljud. Detta trots att en fläkt ska låta mer på ett högre varvtal det konstaterades att bullret från själva motorn är lägre i den nya motorn. Går man upp i frekvens till 50hz och räknar med 28 stycken nya motorer få man en ljudökning på 5dB på 300m jämfört med den gamla motorn. Denna går att sänka 3dB om man lyckas eliminera den intilliggande väggens ljudreflekterande egenskaper. Den nya motorn rekommenderas då den har många fördelar och vill man köra på högre frekvenser kan man med fördel använda sig utav ljudabsorbenter längs väggen för att eliminera dennas dubblerande effekt på ljudnivån.

  • 50.
    Sathre, Roger
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Gustavsson, Leif
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Haus, Sylvia
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för bygg- och energiteknik (BE).
    Time Dynamics and Radiative Forcing of Forest Bioenergy Systems2013Ingår i: Forest BioEnergy Production: Management, Carbon Sequestration and Adaptation, Springer, 2013, s. 185-206Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    In this chapter we explore the temporal dynamics of using forest bioenergy to mitigate climate change. We consider such issues as: growth dynamics of forests under different management regimes; the substitution effects of different bioenergy and biomaterial uses; temporary carbon storage in harvested biomass; the availability of different biomass fractions at different points of a wood product life cycle; and changes in carbon content of forest soils. We introduce the metric of radiative forcing, which quantifies the accumulating energy due to the global greenhouse effect, and we describe a method to estimate quantitatively and to compare the cumulative radiative forcing (CRF) of forest bioenergy systems and reference fossil energy systems. In three case studies, we describe the time dynamics and estimate the CRF profiles of various forest biomass systems.

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