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Noise emissions from transportation remain one of the greatest environmental issues of modern day. Inhabitants in urban environments are especially exposed, with almost 80 million people in the European Union exposed to noise levels exceeding the recommended limits set by the World Health Organization (WHO). While the health-related effects from exposure of traffic noise are problematic and of utmost importance to reduce, availability to efficient transport is also an essential necessity. These conflicting requirements on transportation calls for a more holistic approach to traffic analysis, and to understand the relation between these effects from the traffic. This work investigates properties of traffic, such as the exposure of noise emissions, the vehicle-specific energy demand and duration, to analyse the sustainability of transport. The traffic simulation software SUMO is used to provide a discrete traffic model with individual vehicles, combined with the European vehicle noise source model IMAGINE used to model discrete sound sources that allow for directivity in the sound field and is speed- as well as acceleration-dependent. The resulting cost related to the exposure of noise is then evaluated at several measurement points in the network using a willingness-to-pay (WTP) model. This allows for an analysis of the relation between noise exposure cost and energy efficiency through the estimation of the vehicle-specific energy demand. A time-varying traffic demand is added to analyse the effects of a varying traffic density and congestion to the relation between the different properties. Additionally, the concept of allocating the noise exposure cost down to individual vehicles by means of contributed acoustic energy is expanded to take the main contributing vehicles and time-segments into consideration, and to allow for a non-linear weighting factor. These allocation strategies also allow for a bias to assign a higher cost to noisier vehicles, as vehicles that contribute more to the overall noise exposure than others may be more easily identified. Lastly, the relation between the traffic properties are analysed by means of correlation. Initial studies indicate that the correlation is dependent on the traffic density and the amount of vehicle interaction. Trafikbuller är en av de största miljöproblemen idag. Invånare i stadsmiljöer är särskilt utsatta, där nära 80 miljoner personer i Europeiska Unionen är utsatta för bullernivåer som överskrider Världshälsoorganisationens (WHO) angivna gränsvärden. Medan de hälso-relaterade effekterna från exponering av buller är på en ohållbar nivå och bör reduceras, så är även tillgänglighet till effektiv transport en nödvändighet. Dessa motstridiga krav på transportnätverket kräver en mer holistisk syn på trafikanalys, för att förstå relationen mellan dessa effekter från trafiken. Detta arbete undersöker de effekter som uppstår från trafiken, såsom bullerexponering, det fordons-specifika energibehovet och tiden i trafiken, för att analysera hållbarhetsaspekter för transporter. I detta arbete används trafiksimuleringsprogrammet SUMO för att erhålla en diskret trafikmodell med individuella fordon, i kombination med den europeiska fordonsbullermodellen IMAGINE som används för att modellera diskreta bullerkällor som tar hänsyn till direktivitet i ljudfältet samt fart- och accelerationsberoende. Den resulterande kostnaden för bullerexponeringen beräknas därefter för ett stort antal mätpunkter i nätverket genom en modell för betalningsvilja (WTP). Detta tillåter en analys av förhållandet mellan kostnad från bullerexponering och energieffektivitet baserat på det fordonsspecifika energibehovet. Ett tidsvarierande trafikflöde läggs på för att analysera effekterna från en varierande trafiktäthet och trängsel på förhållandet mellan de olika egenskaperna. Dessutom expanderas konceptet att allokera den buller-relaterade kostnaden ner till enskilda fordon baserat på deras enskilda bullerbidrag. Detta för att potentiellt kunna allokera en större del av den totala kostnaden till fordon som bidrar särskilt mycket till den totala bullernivån eller till särskilda tidsegment med höga bullernivåer, samt att tillåta en ickelinjär viktfunktion. Dessa allokeringsstrategier ger också möjligheten att allokera en högre kostnad till bullriga fordon, då fordon som bidrar mer till den totala bullernivån kan lättare identifieras. Slutligen analyseras förhållandet mellan trafikegenskaperna utifrån korrelation. Inledande studier visar att korrelationen beror på trafiktätheten och mängden fordonsinteraktion i trafiken.

As it becomes more important to replace fossil fuels with alternative fuels, biofuels like ethanol are becoming more commercially used. The increased use of ethanol brings good influences such as lower impact on the environment. However, the use of ethanol can also bring negative effects regarding corrosion of metals. In the automotive industry aluminium has been seen affected by a novel very aggressive corrosion phenomenon, alcoholate corrosion. This master thesis investigation has investigated the effect of a few parameters of importance for alcoholate corrosion; water, temperature, time and pressure. The aluminium alloys AA6063 and A380 have been investigated and the capacity of five different surface treatments of AA6063 has been tested to observe if they inhibit the effect of alcoholate corrosion. Throughout the experiments the water dependence of alcoholate corrosion has showed to be of large importance for the corrosion process. An increase in water content will postpone the start of alcoholate corrosion or prevent corrosion to occur. A correlation between temperature and time has been observed. Higher temperatures results in a shorter time period of exposure before alcoholate corrosion occurs, and vice versa. The effect of different pressures was investigated and showed no effect on alcoholate corrosion when using pressurisation with the inert nitrogen gas. All surface treatments revealed a capacity to protect the aluminium alloy against alcoholate corrosion to different extent. The electroless nickel plating seemed to prevent alcoholate corrosion while the Keronite coating seemed more sensitive to this form of corrosion.

QC 20160311 Mistra Arctic Sustainable Development

Although current trends in global warming are of great concern, energy demand is still increasing, resulting in increasing pollutant emissions. To address this issue, we need reliable renewable energy sources, lowered pollutant emissions, and efficient and profitable processes for energy conversion. We also need to improve the use of the energy, produced by existing infrastructure. Consequently, the work presented in this thesis aims at investigating current scientific and technological challenges in energy conversion through biomass gasification and the alternative use of fossil fuels, such as diesel, in the generation of cleaner electricity through auxiliary power units in the transport sector. Production of chemicals, syngas, and renewable fuels is highly dependent on the development and innovation of catalytic processes within these applications. This thesis focuses on the development and optimization of catalytic technologies in these areas. One of the limitations in the commercialization of the biomass gasification technology is the effective catalytic conversion of tars, formed during gasification. Biomass contains high amounts of alkali impurities, which pass on to the producer gas. Therefore, a new material with alkali tolerance is needed. In the scope of this thesis, a new catalyst support, KxWO3 – ZrO2 with high alkali resistance was developed. The dynamic capability of KxWO3 – ZrO2 to store alkali metals in the crystal structure, enhances the capture of alkali metals "in situ". Alkali metals are also important electronic promoters for the active phase, which usually increases the catalysts activity and selectivity for certain products. Experimental results show that conversion of 1-methylnaphathalene over Ni/KxWO3 – ZrO2 increases in the presence of 2 ppm of gas-phase K (Paper I). This support is considered to contribute to the electronic equilibrium within the metal/support interface, when certain amounts of alkali metals are present. The potential use of this support can be extended to applications in which alkali "storage-release" properties are required, i.e. processes with high alkali content in the process flow, to enhance catalyst lifetime and regeneration. In addition, fundamental studies to understand the adsorption geometry of naphthalene with increasing temperature were performed in a single crystal of Ni(111) by STM analyses. Chapter 9 presents preliminary studies on the adsorption geometry of the molecule, as well as DFT calculations of the adsorption energy. In relation to the use of clean energy for transport applications, hydrogen generation through ATR for FC-APUs is presented in Papers II to V. Two promoted RhPt bimetallic catalysts were selected in a previous bench scale study, supported on La2O3:CeO2/d – Al2O3 and MgO : Y2O3/CeO2 – ZrO2. Catalyst evaluation was performed in a fullscale reformer under real operating conditions. Results showed increased catalyst activity after the second monolithic catalyst due to the effect of steam reforming, WGS reaction, and higher catalyst reducibility of the RhxOy species in the CeO2 – ZrO2 mixed oxide, as a result of the improved redox properties. The influence of sulfur and coke formation on diesel reforming was assessed after 40 h on stream. Sulfur poisoning was evaluated for the intrinsic activity related to the total Rh and Pt area observed after exposure to sulfur. Sulfur concentration in the aged catalyst washcoat was observed to decrease in the axial direction of the reformer. Estimations of the amount of sulfur adsorbed were found to be below the theoretical equilibrated coverage on Rh and Pt, thus showing a partial deactivation due to sulfur poisoning. QC 20150213

Energy conservation and decarbonization of the building stock is a way to achieve sustainable development goals. Visualizing and monitoring energy consumption with a help of Decision Support Systems (DSS) can help to inform and support making decisions to conserve energy, reduce emissions, save costs and improve overall quality of life. However, there are no clear guidelines to how such tools should be designed, and which demands from the different stakeholders they should meet. This literature review presents an overview of existing DSSs that calculate, optimize, visualize and monitor energy usage in buildings. A total of 22 studies have been selected through an in-depth literature search and analysed in a study matrix split into four categories describing relevant features that are vital for each DSS. The study has identified that main functions of analysed DSSs are: 1) to compare costs for CO2 emission reduction or energy saving for various actions; and 2) to compare current energy performance of buildings. Finally, it has shown a variety of needs for different stakeholders that affect the choice of methods and data used by DSS. Hence it is crucial to ensure early alignment of the needs and functions for the developed tools, in order to be efficient in decision-support for better energy efficiency and climate mitigation. Energibesparing och koldioxidminskning av befintliga byggnader är ett sätt att uppnå de globala målen. Att visualisera och övervaka energiförbrukningen i byggnader med hjälp av ett beslutsstödsystem kan hjälpa till att informera och stödja beslut för att spara energi, minska utsläppen, minska kostnaderna och överlag öka livskvalitén. Det finns dock inga tydliga riktlinjer för hur ett verktyg kan utformas och vilka behov som behöver tillfredsställas från de olika intressenterna. Denna litteraturstudie presenterar en översikt över befintliga beslutsstödsystem som beräknar, optimerar, visualiserar och övervakar energianvändningen i byggnader. Genom en ingående litteratursökning valdes 22 olika studier för en djupare analys med hjälp av en studiematris delad inom fyra olika kategorier som beskriver relevanta funktioner som är viktiga för varje beslutsstödsystem. Studien har identifierat att huvuduppgifterna för varje analyserad beslutsstödsystem är: 1) att jämföra kostnader för CO2 minskning och energibesparing för olika åtgärder; och 2) att jämföra aktuell energiprestanda av byggnader. Slutligen har det visat att olika behov från intressenter styrt de val av metoder och data som används i respektive beslutsstödsystem. Därför är det viktigt att säkerställa en tidig anpassning av behov och huvuduppgifter för de utvecklade verktygen för att vara effektiva i beslutsstöd kring energieffektivisering och klimatpåverkan. 

This project aimed to investigate various areas of improvement in crushing equipment for a digital service, from a sustainability perspective. The results were to be presented in a list where each point corresponds to an area with potential to be implemented in the digital assistance tool. In addition, the sustainability aspect of the items on the list would be presented through a rough estimate of the savings that could be made, either in the form of energy or as emissions. Delimitations were made, to only look at the stationary units, mainly the cone crusher, and to focus on CO2 emissions and energy consumption. A benchmarking was made for companies in similar and in other industries. The method for the project was implemented qualitatively with an inductive approach. Interviews were conducted with a number of employees within the company, all with different areas of responsibility, with the aim of gaining an insight into the company and the entire industry as well as to get an overview of which areas a further investigation could be considered in. Then more interviews were conducted with the same people, to shape and refine these areas into items on the list. The list was prioritized based on whether and when in time an implementation in the digital assistance tool would be possible. The result was a list of 14 points where the first 3 are undeniably low-hanging fruits that could be implemented immediately, the 3 points are; Enhanced visualization of current data, Notice of maintenance, Guidance - Troubleshooting Detta projekt gick ut på att undersöka olika förbättringsområden inom krossutrustning för en digital tjänst, ur ett hållbarhetsperspektiv. Resultaten skulle presenteras i en lista där varje punkt motsvarar ett område med potential att implementeras i det digitala hjälpverktyget. Dessutom skulle hållbarhetsaspekten av punkterna på listan presenteras genom en grov uppskattning av de besparingar som kunde göras, antingen i form av energi eller som utsläpp. Avgränsningar gjordes, att bara titta på de stationära enheterna, främst konkrossen samt att fokusera på CO2 utsläpp och energiförbrukning. En benchmarking gjordes för företag i liknande och i andra industrier. Metoden för projektet genomfördes kvalitativt med ett induktivt tillvägagångssätt. Intervjuer gjordes med ett flertal anställda i företaget, alla med olika ansvarsområden, med syftet att få en insikt i företaget och hela branschen men även för att få en överblick över vilka områden en ytterligare utredning kunde övervägas inom. Sedan gjordes fler intervjuer med samma personer för att forma och finslipa dessa områden till punkter på listan. Listan prioriterades utifrån om och när i tiden en implementation i det digitala verktyget skulle vara möjlig. Resultatet blev en lista med 14 punkter där de 3 första onekligen är lågt hängande frukter som skulle kunna implementeras omgående, de 3 punkterna är; Förbättrad visualisering av aktuell data, Besked om underhåll, Vägledning - Felsökning.

QC 20110523

QC 20170613

The aim of this study is to perform a baseline energy survey to understand the existing energy demand and usepattern and to verify the feasibility of a small scale poly-generation project supported by renewable sources ofenergy (biogas based) in a rural area of Bangladesh. A poly-generation solution shall provide multiple outputservices of clean gas, electricity and arsenic free water supply. The project requires using animal dung oragricultural waste to produce biogas and electric energy. The study has analyzed the demand of domesticenergy and water of the village named ‘Matipukur’ in the Jessore district in Bangladesh. The study alsoconsidered available biomass feedstock and energy potential surrounding the village area, as well as the socioeconomicstatus of villagers. The case study included a door to door survey to collect relevant information.Three different economic groups in terms of income scale were investigated throughout the study to obtainbetter insight of the energy-water access situation, requirements and related problems in the village. Almost 98% household of this village relies on biomass for energy due to limited access of modern fuel. Thevillage has various biomass potential in the form of animal dung, fuel wood and agricultural waste which can beused for cooking or serve as the basis for other energy carriers. Kerosene is used for lighting. Among thedifferent fuels, dung meets about 44% of the total demand. The contribution of other fuels for domestic use is24% firewood, 22% agricultural waste, and 2% kerosene. The analytical observation found that the annualaverage energy demand of the village is 8.45 GJ per capita. The share of average demand for cooking and3lighting energy is 8.24 GJ per person/year and 0.21 GJ per person/year respectively. The energy consumptionvaries within different income groups. This study has examined the income per capita, family size, education,agricultural land holding per capita, priorities of their annual expenditure etc. which have direct influence onthe fuel consumption pattern of the household. It could be observed that expenses on energy changes as theincome level increases. About awareness of biogas opportunities and willingness to provide feedstock for apoly generation project, the majority of households answered positively, that is, indicating that they wouldcontribute. Educated respondents showed more positive attitude. Regarding changing of traditional cooking,about 95% of the respondents want to change to a more efficient and reliable cooking system to avoid healthand environmental problems associated with indoor biomass cooking. The study has revealed that only cow dung is not enough to produce clean energy according to demand so theco-digestion method is considered to producing biogas from various energy potentials (animal manure &agricultural waste). The poly-generation system could work with the scenario providing electricity and watersupply for the entire household and cooking gas is limited only for 2/3rd household. Rest 1/3rd household fromlow income group then could be supplied with improve cook stove to meet their daily cooking demand and tominimize indoor pollutions. It is observed that, majority of household has expressed their willingness toprovide raw materials for poly-generation plant though they are using. SIDA funded research project "Biogas based poly generation in Bangladesh"

To mitigate climate change, greenhouse gas emissions must be reduced to net-zero in 2050 requiring a drastic transition in today´s energy sector. To achieve this goal, the use of biofuels produced from lignocellulosic feedstocks, including agricultural and forestry residues, is expected to play an important role. The native ability of the anaerobic thermophile Clostridium thermocellum to efficiently degrade lignocellulose makes this microorganism a promising candidate for consolidated bioprocessing of lignocellulosic feedstocks into the biofuel ethanol. However, improvements in ethanol yield, titre, and tolerance are required for industrial implementation. The aim of this thesis was to increase understanding of the central metabolism of C. thermocellum and thereby aid future metabolic engineering and process optimization efforts focused on improving ethanol production from lignocellulosic material. The atypical glycolysis of C. thermocellum uses pyrophosphate (PPi) instead of ATP as phosphoryl donor. This alteration is hypothesized to increase energetic efficiency but simultaneously decrease thermodynamic driving force resulting in lower achievable ethanol titres. As such, improved understanding of the PPi metabolism has both fundamental and applied importance. Knockout studies combined with physiological characterization of four predicted metabolic PPi sources provided valuable insights into the PPi metabolism and demonstrated that the energetic benefits of PPi usage are likely limited. Furthermore, biochemical characterization of the ATP-Pfk from C. thermocellum and other bacteria demonstrated that PPi might be a key allosteric regulator in bacteria with a PPi-dependent glycolysis. The low thermodynamic driving force of the ethanol formation pathway combined with a flexible redox network are key factors that impact ethanol titre, yield, and tolerance in C. thermocellum. Apart from dominant thermodynamic limitations, physiological characterization of wild-type and a non-ethanol producing mutant at various exogenous ethanol concentrations and temperatures demonstrated that biophysical limitations also impact ethanol tolerance. Lowering the cultivation temperature decreased chaotropic effects of ethanol and improved ethanol tolerance. By-product formation and incomplete substrate utilization decrease obtained ethanol yields. To minimize formation of one specific class of by-products, the mechanism behind amino acid secretion in C. thermocellum was investigated. Cellobiose- or ammonium-limited chemostats of wild-type and knockout strains of NADPH-supplying and NADPH-consuming pathways identified catabolic oversupply of NADPH as the main driver behind amino acid secretion. The malate shunt and the ammonium-regulated shift between nitrogen assimilation pathways with differing cofactor specificities were shown to play key roles in NADPH metabolism and amino acid secretion. To improve substrate utilization, laboratory evolution combined with reverse metabolic engineering was used as a tool to provide insights into increased utilization of glucose and fructose. Reproducible and constitutive growth on these hexose sugars was achieved for evolved mutant strains. Additionally, two mutations were identified that are involved in (regulation of) transport or metabolism of these hexose sugars. Together these findings provide valuable insights into the central metabolism of C. thermocellum and aid future optimizations of this organism for consolidated bioprocessing of lignocellulosic feedstocks into fuels and chemicals. För att mildra klimatförändringarna måste utsläppen av växthusgaser minskas till nettonoll år 2050 vilket kräver en drastisk förändring i dagens energisektor. För att uppnå detta mål förväntas användningen av biobränslen producerade från lignocellulosabaserade råmaterial, såsom jordbruks- och skogsrester, spela en viktig roll. Den naturliga förmågan att effektivt bryta ned lignocellulosa hittas hos den anaerobiska termofilen Clostridium thermocellum och gör denna mikroorganism till en lovande kandidat för konsoliderad bioprocessering av lignocellulosabaserade råmaterial till biobränslet etanol. För industriell implementering krävs dock förbättringar av etanolutbyte, -titer och -tolerans. Syftet med denna avhandling var att öka förståelsen av C. thermocellums centrala metabolism och därigenom vägleda framtida insatser inom metabol ingenjörskonst och processoptimering för att förbättra etanolproduktionen från lignocellulosabaserade råvaror. Den atypiska glykolysen hos C. thermocellum använder pyrofosfat (PPi) i stället för ATP som fosforyldonator. Denna skillnad har hypotiserats öka energieffektiviteten men samtidigt minska den termodynamiska drivkraften, och resultera i en lägre uppnåbar etanoltiter. Därför är en förbättrad förståelse av PPi-metabolismen viktig ur fundamentala och applicerbara perspektiv. Knockoutstudier tillsammans med fysiologisk karaktärisering av fyra predikterade metaboliska PPi-källor gav värdefulla insikter i PPi-metabolismen och visade att energifördelarna med användningen av PPi sannolikt är begränsade. Vidare visade biokemisk karaktärisering av ATP-Pfk från C. thermocellum och andra bakterier att PPi kan vara en viktig allosterisk regulator för bakterier med en PPi-beroende glykolys. Den låga termodynamiska drivkraften hos etanolproduktionsvägen kombinerat med ett flexibelt redoxnätverk är nyckelfaktorer som påverkar etanoltitern, -utbytet och -toleransen hos C. thermocellum. Förutom övervägande termodynamiska begränsningar visade fysiologisk karaktärisering av vildtypen och en modifierad icke-etanolproducerande stam, vid olika extracellulära etanolkoncentrationer och temperaturer, att även biokemiska begränsningar påverkar etanoltoleransen. Att sänka odlingstemperaturen reducerade de kaotropiska effekterna av etanol och förbättrade etanoltoleransen. Produktion av biprodukter och ofullständigt substratutnyttjande minskar erhållna etanolutbyten. För att minimera produktionen av en specifik klass av biprodukter undersöktes mekanismen bakom aminosyrasekretion hos C. thermocellum. Cellobios- eller ammoniumbegränsade kemostater av vildtypen och knockout-stammar av NADPH-producerande och -konsumerande reaktionsvägar identifierade ett katabolisk överskott av NADPH som den främsta drivkraften bakom aminosyrasekretion. Malatshunten samt det ammoniumreglerade skiftet mellan olika assimileringvägar av kväve med specificitet för olika kofaktorer visade sig spela en nyckelroll i NADPH-metabolismen och aminosyrasekretionen. För att öka substratutnyttjandet användes laboratorieevolution kombinerat med reverse metabolic engineering som verktyg för att ge insikter i hur utnyttjande av glukos och fruktos kan förbättras. Laboratorieevolutionen resulterade i stammar med reproducerbar och konstitutiv tillväxt på dessa hexoser. Sedan identifierades två mutationer involverade i (reglering av) transport eller metabolism av dessa hexoser. Tillsammans ger dessa forskningsrön värdefulla insikter i C. thermocellums centrala metabolism och underlättar framtida optimeringar av denna organism för konsoliderad bioprocessering av lignocellulosabaserat råmaterial till bränslen och kemikalier. QC 2023-04-25