The concept of integration of industries in urban setup is the current trend among researchers and engineers in the field of industrial ecology and environmental engineering. Trend of urbanization forces an increasing human demand for energy, materials, water and other resources. Urban symbiosis nowadays is closely related to the controlling of urban metabolism. Closing material loops works as an effective way for a circular economy where theoretically no waste is generated. In this thesis work, an investigation has been made for studying current symbiotic activities in the city of Linköping and look for any potential energy or by-product synergies from industrial activities and the urban waste streams. Some of the companies have been found to be already engaged in such type of activities, directly or indirectly. Hence, uncovering symbiotic activity is also an important task to consider while assessing the feasibility of a network of industries and urban settlement. Finally, it is concluded that the symbiotic activity in the city of Linköping is developing with discovering of new opportunities from waste and by-products from industries and the city area.  The municipal utility company Tekniska Verken and its subsidiary Svensk Biogas could play the role as anchor tenants and the aeronautics company SAAB, for its huge production line, has good potential to participate in exchange of physical materials.

Background: Logistics is paramount in the business operations as it ensures transit of goods from one point to the other. Green logistics are measures in the logistics systems that are put in place to minimize the environmental implication of logistics operations while at the same time saving on cost. Thus, green logistics is adopted as it conveys a competitive merit which enhances performance of a company. Saudi Basic Industries (SABIC) is one of the biggest petrochemicals in Saudi Arabia and holds the fifth position in the world among the leading producers of petrochemicals. The company already has green logistics in place. Purpose: To explore chemical industries green logistics practices and profitability with a particular case study of SABIC. The goal of this paper was achieved by investigating how has SABIC incorporated green practices into supply chain operations to remain profitable. The study answers “how has chemical industries incorporated green practices into supply chain operations to stay profitable?’ And “how do logistic managers recognize green logistics and to what level do chemical industries apply green logistics? Investigating a chemical industry green logistics is important as it contributes to literature since no single study has been carried out in this area. Suggestions from this study are crucial to SABIC, other chemical industry besides any other industry since in one way or the other companies do logistics. Method: The study utilized interpretivism. This study was a case study type of thesis focusing merely on SABIC, and it employed induction approach as well as the qualitative method of collecting data.  Interviews were used to explore the experiences, beliefs, motivations and views of individual participants. Using non-probability sampling method, five members in SABIC supply chain department were selected. Conclusion: The results show that SABIC or chemical industries utilize most of the green logistics activities (fuel efficiency, route optimization package optimization and calculating carbon emission). However, it was found out that fuel efficiency, route optimizations, and packaging optimization were most common activities. It was also discovered that one major objective of chemical industries going green was to cut cost which contributes positively to its profitability. However, reverse logistics was not familiar because of its nature; it cannot be sufficient on its own.

The Swedish government set a climate goal until the year 2045, to not produce any greenhouse gases until 2045. This study is based on the problems surrounding the climate impact from the construction and real estate sector in Sweden. The construction company Skanska has made a major contribution with the recently new project Juvelen, which today is Sweden's most sustainable building. The demand for constructing buildings with lesser environmental impacts is increasing and constructions as Juvelen may be an important factor to achieve climate goals. Purpose: This study was done to determine the carbon dioxide emissions during the construction phase of Juvelen, which includes the production phase and transports to the construction site, as well as the operational phase. Method: This study is based on a literature study, case study, and a reference object. During the case study, interviews were conducted with various people who have participated in the production of Juvelen. The carbon dioxide calculations consisted of EPD reports obtained from Strängbetong and VSAB. The carbon dioxide calculations for the operational phase were performed through different scenarios with three different scenarios types of energy. Results: The result for Juvelen's carbon dioxide emissions during the construction phase, based on the quantitative data that had obtained from Strängbetong and VSAB, was approximately 3,568 tonnes of CO2e. Renewable High had an emission of 96,472.61 kg CO2e during the 50-year analysis period. Renewable Medium received a sum of 2,519,339.7 kg CO2e and Renewable Low 11,961,913.29 kg CO2e. The 100-year analysis period for the operational phase showed the double value of the 50-year analysis period. Based on the current study and an interview with Ambjörn Gille, it appears that Skanska is making efforts to achieve climate goals by 2045. Conclusions: The conclusion that the work came to was that to achieve the climate goal of net-zero emissions, its necessary that the entire construction and real estate sector needs to adapt, apply new and innovative technology. The differences that emerged from the comparison of the production, operating phase for Juvelen were the choice of material, construction process, and method for construction of Juvelen and the choice of energy scenario.

Industries have faced challenges trying to lower carbon emissions and reach climate goals solely with energy efficiency and renewable energy sources but there are still some emissions that will not be mitigated by this. The purpose of this work has been to evaluate bio-energy with carbon capture and storage with co-combustion in a current study as a way to breach the gap and achieve net zero emissions on AstraZenecas production site Snäckviken. A carbon audit based on GHG Protocol has been performed to evaluate the total emissions at the site. Energy calculations were performed based on the possibilities of co-combustion with waste solvent and biofuel to produce process steam. With the flue gas characteristics for the combustion, calculations for a post combustion carbon capture plant using MEA solvent was made. An economic evaluation has been performed based on a reference plant and carbon captured for the current study. The results showed that the carbon capture lowered the emissions for the production site from 1 020 tons CO2 per year to - 2 400 tons CO2 at a cost of 1 360 SEK/tons CO2. The CO2 avoidance cost was high compared to other studies due to lower capacity. However, great savings could be m ade from handling the waste solvent on site instead of paying for the destruction of the waste. Therefore, a carbon capture plant could still be feasible for the current study.

In response to the ever-intensifying urgency for environmental preservation, the imperative for sectors with substantial carbon footprints to adapt and drive the transition to a low carbon economy is apparent. Sustainability transitions, signifying systemic changes towards sustainable socio-technical systems, emerge as critical in this context, especially within the banking sector. This industry, anchored by its pervasive Information Technology (IT) infrastructure, stands as a key actor in the paradigm shift towards global sustainability. This study investigates the implications of the global transition towards net-zero emissions by 2050 for the IT strategy of banks. This transition necessitates significant changes in the banking sector’s practices, with a particular focus on reducing energy consumption and promoting sustainable operations. The paper presents an in-depth investigation of the factors that banks need to address when adapting their IT strategy to align with these imminent changes. The research methodology followed a qualitative research design, with semi-structured interviews conducted among banking sector practitioners serving as the primary data collection method. Additionally, the study applied the Technological-Organizational-Environmental (TOE) framework to analyze the adoption of sustainable practices in the banking sector. This framework allowed for a comprehensive understanding of the multifaceted nature of the transition towards net-zero emissions, considering the intertwined aspects of technology, organization, and environment. The findings of this research reveal significant insights into the key drivers and strategies required for banks as they make decisions about their IT strategies, particularly in response to the transition towards net-zero emissions. The urgency of environmental sustainability and its integration into strategic planning have emerged as primary drivers, leading to the adoption of Green IT for balancing operational efficiency with environmental responsibility. This strategy has influenced banks’ responses and adaptation by prompting introspective resource management, integrating sustainability into organizational culture, and shaping an environmentally conscious workforce. In conclusion, despite facing various complexities, banks are demonstrating resilience and adaptability in their transition towards sustainability, indicating a future of continuous innovation and transformative practices firmly rooted in sustainability. The findings from this research significantly contribute to the existing body of knowledge, offering deeper insights into the interplay between banking practices and the urgent transition towards net-zero emissions. Future research could further enrich this understanding byassessing the effectiveness of banks’ sustainability initiatives, their achievements against set sustainability targets, and the evolving role of Green IT in driving sustainable banking. / Det växande behovet av miljömässig hållbarhet markerar tydligt nödvändigheten för sektorer med storakoldioxidavtryck att anpassa sig och driva övergången till en ekonomi med minskade koldioxidutsläpp. Övergången till hållbarhet, som innebär systematiska förändringar mot hållbara socio-tekniska system, framstår som avgörande i detta sammanhang, särskilt inom banksektorn. Denna bransch, förankrad av sin omfattande IT-infrastruktur, är en viktig aktör i det paradigmskifte som leder mot global hållbarhet. Denna studie undersöker vad den globala övergången mot nettonollutsläpp fram till 2050 innebär för bankernas IT-strategier. Denna övergång kräver omfattande anpassningar inom banksektorn, med särskild inriktning på att minska energiförbrukningen och främja hållbara verksamhetsmetoder. Rapporten presenterar en djupgående undersökning av de faktorer som banker behöver ta hänsyn till när de anpassar sin IT-strategi för att möta dessa förestående förändringar. Studiemetoden följde en kvalitativ forskningsdesign, med semistrukturerade intervjuer genomförda bland experter och yrkesverksamma inom banksektorn som den primära metoden för datainsamling. Studien applicerade dessutom ramverket Technological-Organizational-Environmental (TOE) för att analysera införandet av hållbara praxis i banksektorn. Detta ramverk möjliggjorde en omfattande förståelse för den flerdimensionella naturen av övergången mot nettonollutsläpp, med hänsyn till de sammankopplade aspekterna av teknik, organisation och externa faktorer. Studiens resultat ger värdefulla insikter om de huvudsakliga drivkrafterna och strategierna som bankerna behöver för att fatta beslut om sina IT-strategier, särskilt i samband med övergången till nettonollutsläpp. Det kritiska behovet av miljömässig hållbarhet och dess integrering i strategisk planering har vuxit fram som centrala drivkrafter, vilket har lett till att Grön IT har antagits för att balansera operativ effektivitet med miljömässigt ansvarstagande. Denna strategi har påverkat bankers respons och anpassning genom att stödja självgranskande resurshantering, integrera hållbarhet i organisationskulturen, och forma en miljömedveten arbetskraft. Sammanfattningsvis, trots mångfald av utmaningar, visar banker motståndskraft och anpassningsförmåga i sin övergång mot hållbarhet, vilket indikerar en framtid av kontinuerlig innovation och omformande metoder som är starkt förankrade i hållbarhet. Resultaten från denna studie bidrar till det befintliga kunskapsfältet, och erbjuder djupare insikter i samspelet mellan bankpraxis och den kritiska övergången mot nettonollutsläpp. Framtida studier kan ytterligare berika denna förståelse genom att utforska effektiviteten i bankers hållbarhetsinitiativ, deras framsteg mot uppsatta hållbarhetsmål, och den utvecklande rollen för Grön IT i att driva hållbar bankverksamhet.

Norway has already an almost emission-free power production and its sales of zero-emission light-duty vehicles surpassed 30% in 2018; a natural next challenge is to identify ways to reduce emissions of heavyduty vehicles. In this work the possibilities to deploy Fuel Cell Electric Trucks (FCET) on the route Oslo-Trondheim are analyzed by doing a techno-economic analysis. The literature study identified that in average 932 kton goods where transported between the cities. The preferred road choice goes through Østerdalen and that an average load for a long-distance truck is 16 tons. The methodology used in the study is based on cost curves for both truck and infrastructure, and a case study with various scenarios is evaluated to find a profitable business case for both an FCET fleet and its infrastructure. The cost curves for trucks are based on total cost of ownership (TCO) as a function of hydrogen price, while the levelized cost of hydrogen (LCOH) is used to present the cost of infrastructure. An analysis was made to identify the trucks component sizes and a FCET for this route would require an onboard hydrogen storage of 46 kg, a fuel cell stack with a nominal power of 200 kW, a battery of 100 kWh (min SOC 22%), and an electric motor with a rated power of 402 kW. TCO was calculated both for an FCET based on the dimensioned components and a biodiesel truck. The results show that an FCET purchased in 2020 can be competitive with biodiesel with a hydrogen price of 38.6 NOK/kgH2. While the hydrogen price can increase to 71.8 NOK/ kgH2 if the FCET is purchased in 2030. To identify the most suitable infrastructure, four different designs of hydrogen refueling stations (HRS) were compared. Furthermore, hydrogen production units (HPUs) with both alkaline or PEM type water electrolyzer were compared. The analysis in this study showed that the most cost competitive option was a 350-bar HRS without cooling, which only can serve type III onboard storage tanks. A HPU with alkaline electrolyzer was the most price competitive alternative. In case each HRS is refueling more than 7 FCETs per day, an HPU in direct connection to HRS is the preferred infrastructure setup. Three HRS are required along the route to ensure a minimum service level for the FCETs. When the TCO of the fuel cell truck and LCOH of the hydrogen infrastructure were compared for a 2020 scenario, no feasible solution was identified. The cost of installing three HRS in 2020, serving a fleet of 14-24 trucks, would cost 16.0 – 17.6 million NOK/year more than a fleet based on biodiesel trucks. In a future scenario, where both the FCET and infrastructure costs decrease due to expected learning curves, a business case can be found if at least 5 FCETs were refueling at each HRS on daily basis, which corresponds to a total fleet of approx. 24 FCETs. Finally, a set of clear recommendations on how to improve the techno-economic analysis in future studies are provided. Both by identifying areas lacking sufficient documentation and by providing steps how the tecno-economic model could be enhanced. / Norge har redan en nästintill utsläppsfri elproduktion och nollutsläppsbilar stod för mer än 30% av nybilsförsäljningen under år 2018. En naturlig nästa utmaning är att finna sätt att minska utsläpp från lastbilar. I detta examensarbete analyseras möjligheterna att introducera bränslecellslastbilar (FCET) efter dess engelska förkortning) på sträckan Oslo - Trondheim genom att göra en teknisk-ekonomisk bedömning. Litteraturstudien visade att i genomsnitt 932 kton gods fraktas mellan städerna, att vägen genom Østerdalen är att föredra och att genomsnittlig last för en långtradare är 16 ton. Arbetets metod bygger på att identifiera kostnadskurvor för både lastbilar och infrastruktur. Dessa kurvor kombineras i olika scenarier för att finna omständigheter där både en FCET-flotta och dess infrastruktur är lönsamma. Kostnadskurvorna för lastbilar baseras på den totala ägandekostnaden (TCO) efter dess engelska förkortning) som en funktion av vätgaspriset, medan den utjämnade kostnaden för vätgas (LCOH) efter dess engelska förkortning) används för att presentera kostnaden för infrastruktur. En analys gjordes för att finna passande storlek på FCET drivlina. För den specifika sträckan krävs en hydrogentank på 46 kg, en bränslecellstack med nominell effekt på 200 kW, ett batteri på 100 kWh (min SOC 22%) och en elmotor med nominell effekt på 402 kW. TCO beräknades både för en FCET baserat på de dimensionerade komponenterna och en lastbil som går på biodiesel. En FCET som köps 2020 blir konkurrenskraftig om vätgaspriset är 38,6 NOK/kgH2, medan vätgaspriset kan öka till 71,8 NOK/kgH2 om FCET köps 2030. Skillnaden är baserad på en framtida prisnedgång för FCET. För att finna den mest lämpliga lösningen på infrastruktur; analyserades fyra olika utformningar av vätgaspåfyllningsstationer (HRS). I tillägg jämfördes vätgasproduktionsenheter (HPU) baserat på antingen alkalisk eller PEM-typ av elektrolysator. Resultaten visade at en 350 bar HRS utan kylning, som endast kan fylla typ III lagringstankar, som det billigaste alternativet. Den alkaliska elektrolysatorn kunde producera vätgas för något lägre kostnad. Det billigaste alternativet för infrastruktur av de olika framtagna scenarios var att placera HPU bredvid HRS om minst 7 FCET tankar dagligen på varje station. Minst 3 HRS krävs längs rutten för att tillhandahålla en minsta servicenivå för FCET. När TCO för bränslecellslastbil och LCOH för infrastruktur jämfördes för ett 2020-scenario så fanns det ingen lönsam lösning. Kostnaden för att installera 3 HRS år 2020 som betjänar en lastbilflotta mellan 14-24 lastbilar skulle kosta 16,0 - 17,6 miljoner NOK/år mer än en lastbilsflotta som går på biodiesel. I ett framtida scenario där både FCET- och infrastrukturkostnaderna minskar på grund av större produktionsvolymer så kan vätgassatsning bli lönsam om minst 5 FCET tankar dagligen på varje HRS. Det motsvarar en lastbilsflotta på omkring 24 lastbilar för hela rutten. Till slut finns en rad klara rekommendationer om hur den tekno-ekonomiska analysen kan förbättras. Det upptäcktes både områden med otillräcklig dokumentation och summerades hur den teknoekonomiska modellen kan förbättras.

It is known that the decarbonization of our economy is crucial for our quest to mitigate climate change and build a sustainable society. Governments are reviewing strategies to eliminate, or at least minimize, the release of carbon emissions into the atmosphere. These efforts are not limited to national energy networks, but also extended to industry and other carbon-intensive sectors. In general, the Pulp & Paper industry is regarded as bio-based and relatively sustainable since most of its raw materials are recycled or come from biogenic sources. However, this is an energy-intensive industry, and even though bioenergy covers most of the energy needs at pulp plants, recycled paper mills do not count on the same resources and rely heavily on fossil fuels to power their operations. This study was performed to assess and compare different decarbonization pathways available for a recycled paper mill. For this, operational data was gathered to characterize the thermal and electric demands and assess locally available resources. Simultaneously, scientific literature was consulted to assemble a technology portfolio, from which the most suitable technologies were selected. Carbon capture and storage, electrification, and hydrogen were chosen to be tested, under different scenarios, using an energy modelling software. Finally, the combinations were evaluated and compared. It was found that under ideal conditions it is possible to achieve an emissions reduction of almost 100% via electrification and hydrogen-based options. However, this would represent a significant increase in the operating cost of the energy system and would depend on the development of the necessary infrastructure. The most promising alternative for this site was a combination of electrification and green electricity purchase agreements. However, further work is needed to improve the efficiency of the energy use and generation, to achieve a carbon-neutral operation without incurring elevated costs. / Det är känt att avkarboniseringen av vår ekonomi är avgörande för vår strävan att mildra klimatförändringarna och bygga ett hållbart samhälle. Regeringar ser över strategier för att eliminera, eller åtminstone minimera, utsläpp av koldioxid i atmosfären. Dessa ansträngningar är inte begränsade till nationella energinät, utan sträcker sig även till industrin och andra kolintensiva sektorer. Massa- och pappersindustrin är biobaserad och relativt hållbar eftersom de flesta av dess råvaror återvinns eller kommer från biogena källor. Detta är dock en energiintensiv industri, och även om bioenergin täcker det mesta av energibehovet vid massafabrikerna, räknar inte återvunnet pappersbruk med samma resurser som är starkt beroende av fossila bränslen för att driva sin verksamhet. Denna studie utfördes för att bedöma och jämföra olika avkolningsvägar tillgängliga för ett återvunnet pappersbruk. För detta samlades operativa data in för att karakterisera de termiska och elektriska kraven och bedöma lokalt tillgängliga resurser. Samtidigt konsulterades vetenskaplig litteratur för att sammanställa en teknologiportfölj, från vilken de mest lämpliga teknologierna valdes ut. Kolavskiljning och lagring, elektrifiering och väte valdes ut för att testas, under olika scenarier, med hjälp av en mjukvara för energimodellering. Slutligen utvärderades och jämfördes kombinationerna. Man, fann att det under ideala förhållanden är möjligt att uppnå en utsläppsminskning på nästan 100 % via elektrifiering och vätebaserade alternativ. Detta skulle dock innebära en betydande ökning av driftskostnaden för energisystemet och skulle bero på utvecklingen av den nödvändiga infrastrukturen. Det mest lovande alternativet för denna plats var en kombination av elektrifiering och köp av grön el. Det krävs dock ytterligare arbete för att effektivisera energianvändningen och energiproduktionen, för att uppnå en koldioxidneutral drift utan förhöjda kostnader.

This work was done on the behalf of Sala-Heby Energi on the use of solar energy in district heating facilities around Sala municipality, the work has looked at the potential in using solar panels for heating through electricity and found that it was possible but it wasn’t economically feasible to recover the investment costs during the lifetime of the solar cells if the investment cost were above 4000 kr per solar panel for most of the district heating networks. Another viable way to generate district heating was with the use of solar thermal collectors the technology was found to be both viable and potentially economically feasible, this was due to the lower size of land needed for allocation and lower overall investment costs, however reaching the company associated with this technology was not possible in the given timeframe. This work analysed Energy storage solutions and the most optimal solution for thermal storage in the use for district heating was the use of hot water tanks, this had the ability to both store energy for night-time use and to have the lowest associated cost.

[ES] En los últimos años, la preocupación mundial con el aumento de las emisiones antropogénicas de gases de efecto invernadero ha motivado a las industrias del transporte y la energía a moverse hacia el desarrollo de tecnologías sostenibles con bajas o nulas emisiones de contaminantes de plantas de generación de potencia. Con este escenario, la oxicombustión surge como uno de los métodos más prometedores para mitigar la huella ambiental de plantas de generación de potencia, al erradicar sus emisiones contaminantes del tubo de escape, además de permitir la captura de dióxido de carbono (CO2) de sus gases producidos en la combustión. De esta manera, el oxígeno puro (O2) se diluye con el gas de escape recirculado para que reaccione con el combustible en el proceso de combustión y, de este modo, la corriente de gases de escape, compuesta principalmente por CO2 y vapor de agua, puede ser sometida a etapas elementales de enfriamiento y presurización para capturar CO2 de alta pureza a temperatura ambiente. Dado este contexto, en esta tesis, se desarrolla un modelo de sistema autosostenible a oxicombustión con captura de carbono para un motor policilíndrico de encendido por compresión (MEC) de 2,2 litros turboalimentado y de inyección directa como demostración de viabilidad de este concepto propuesto, considerando su aplicación potencial para el desarrollo de plantas de potencia de altas prestaciones con cero emisiones. En tales circunstancias, se emplea una membrana conductora mixta iónica-electrónica para generar O2 a partir del aire local. Para ello, se recupera la energía residual de los gases de escape mediante un ciclo Brayton adaptado con el fin de proporcionar las condiciones adecuadas para el correcto funcionamiento de la membrana en términos de temperatura y relación de presión alimentación-permeado. Asimismo, se diseña un sistema de captura de carbono (CC) local, compuesto esencialmente por dos compresores alternativos, tres unidades de refrigeración con separación de líquidos (flashes) y un tanque de almacenamiento de CO2, teniendo en cuenta las temperaturas de salida de los flashes y la presión de funcionamiento de la última etapa de purificación del CO2. En primer lugar, se diseña el modelo del sistema de oxicombustión con el motor y sus componentes auxiliares (intercambiadores de calor y turbocompresores) y, a continuación, el sistema es evaluado bajo condiciones de oxicombustión para la curva de plena carga del motor desde 1250 rpm hasta 3500 rpm en ausencia del CC, contrastando sus resultados con el comportamiento del MEC convencional de referencia. En segundo lugar, se amplía el mapa de funcionamiento de carga del motor de oxicombustión hasta los límites de estabilidad del sistema modificando el dosado oxígeno-combustible y la temperatura de los gases de escape para tres regímenes del motor. Por último, se diseña el CC y se lo acopla a la unidad de generación de O2, reciclando el agua y el exceso de O2 del CC de nuevo a la admisión del motor. A este respecto, un barrido es llevado a cabo sobre el inicio de la inyección y el flujo másico de agua recirculada para encontrar el punto de funcionamiento óptimo a 3500 rpm con respeto a la compensación entre las prestaciones del motor y la potencia de refrigeración adicional. A continuación, se mejora y adapta el modelo del sistema completo de oxicombustión con captura de carbono para una aplicación realista a escala de laboratorio y una prueba de concepto experimental, siguiendo la misma filosofía de compensación. Aunque el diseño final del motor de oxicombustión con captura de carbono presenta un ligero empeoramiento de prestaciones comparado con el MEC convencional de referencia a 3500 rpm, este nuevo concepto propuesto puede seguir siendo competitivo desde el punto de vista de la eficiencia energética como tecnología emergente que puede contribuir a la concepción de plantas de generación de potencia con emisiones cero a escala industrial comercial. / [CA] En els darrers anys, la preocupació mundial amb l'augment de les emissions antropogèniques de gasos d'efecte hivernacle ha motivat les indústries del transport i l'energia a moure's cap al desenvolupament de tecnologies sostenibles amb baixes o nul·les emissions de contaminants de plantes de generació de potència. Amb aquest escenari, l'oxicombustió sorgeix com un dels mètodes més prometedors per mitigar l'empremta ambiental de plantes de generació de potència, en eradicar les emissions contaminants del tub d'escapament, a més de permetre la captura de diòxid de carboni (CO2) dels seus gasos produïts a la combustió. D'aquesta manera, l'oxigen pur (O2) es dilueix amb el gas d'escapament recirculat perquè reaccioni amb el combustible en el procés de combustió i així el corrent de gasos d'escapament, compost principalment per CO2 i vapor d'aigua , pot ser sotmesa a etapes elementals de refredament i pressurització per capturar CO2 d'alta puresa a temperatura ambient. Atès aquest context, en aquesta tesi, es desenvolupa un model de sistema autosostenible a oxicombustió amb captura de carboni per a un motor policilíndric d'encesa per compressió (MEC) de 2,2 litres turboalimentat i d'injecció directa com a demostració de viabilitat d'aquest concepte proposat , considerant la seva aplicació potencial per al desenvolupament de plantes de potència d'altes prestacions amb zero emissions. En aquestes circumstàncies, es fa servir una membrana conductora mixta iònica-electrònica per generar O2 a partir de l'aire local. Per això, es recupera l'energia residual dels gasos d'escapament mitjançant un cicle Brayton adaptat per tal de proporcionar les condicions adequades per al funcionament correcte de la membrana en termes de temperatura i relació de pressió alimentació-permeat. Així mateix, es dissenya un sistema de captura de carboni (CC) local, compost essencialment per dos compressors alternatius, tres unitats de refrigeració amb separació de líquids (flaixos) i un tanc d'emmagatzematge de CO2, tenint en compte les temperatures de sortida dels flaixos i la pressió de funcionament de l'última etapa de purificació del CO2. En primer lloc, es dissenya el model del sistema d'oxicombustió amb el motor i els seus components auxiliars (intercanviadors de calor i turbocompressors) i, a continuació, el sistema és avaluat sota condicions d'oxicombustió per a la corba de plena càrrega del motor des de 1250 rpm fins a 3500 rpm en absència del CC, contrastant els resultats amb el comportament del MEC convencional de referència. En segon lloc, s'amplia el mapa de funcionament de càrrega del motor d'oxicombustió fins als límits d'estabilitat del sistema modificant el dosatge oxigen-combustible i la temperatura dels gasos d'escapament per a tres règims del motor. Finalment, es dissenya el CC i l'acobla a la unitat de generació d'O2, reciclant l'aigua i l'excés d'O2 del CC de nou a l'admissió del motor. Quant a això, un escombrat és dut a terme sobre l'inici de la injecció i el flux màssic d'aigua recirculada per trobar el punt de funcionament òptim a 3500 rpm respecte a la compensació entre les prestacions del motor i la potència de refrigeració addicional. A continuació, es millora i s'adapta el model del sistema complet d'oxicombustió amb captura de carboni per a una aplicació realista a escala de laboratori i una prova de concepte experimental, seguint la mateixa filosofia de compensació. Tot i que el disseny final del motor d'oxicombustió amb captura de carboni presenta un lleuger empitjorament de prestacions comparat amb el MEC convencional de referència a 3500 rpm, aquest nou concepte proposat pot continuar sent competitiu des del punt de vista de l'eficiència energètica com a tecnologia emergent que pot contribuir a la concepció de plantes de generació de potència amb emissions zero a escala industrial comercial. / [EN] In recent years, a worldwide concern with respect to an increase in anthropogenic greenhouse gas emissions has pushed transport and energy industries towards the development of sustainable technologies with low or zero pollutant emissions from powerplants. Within this scenarios, oxy-fuel combustion arises as one of the most promising methods to mitigate the environmental footprint of powerplants, by eradicating their pollutant tailpipe emissions, in addition to enabling carbon dioxide (CO2) capture from their flue gas. In this case, pure oxygen (O2) is diluted with recirculated exhaust gas to react with fuel for the combustion process and, thereby, the exhaust stream, mainly composed of CO2 and water vapor, may be subjected to elementary cooling and pressurizing steps for capturing high-purity CO2 at ambient temperature. Therefore, in this thesis, a self-sustaining oxy-fuel carbon-capture layout model is developed for a 2.2 liter turbocharged and direct-injection multicylinder compression ignition engine (CIE) as a feasibility demonstration of this proposed concept considering its potential application for development of zero-emission high-duty powerplants. In such circumstances, a mixed ionicelectronic conducting membrane is employed to generate O2 from air in-situ. For this purpose, exhaust gas wasted energy is recovered via a tailored Brayton cycle in order to provide suitable conditions for proper membrane operation in terms of temperature and feed-permeate pressure ratio. Also, an in-situ carbon capture system (CC), composed essentially of two reciprocating compressors, three cooling units with liquid separation (flashes) and a CO2 storage tank, is designed taking into account the flash out temperatures and operating pressure of the last CO2 purification step. Firstly, the oxy-fuel layout model with engine and its auxiliary components (heat exchangers and turbochargers) is designed and then assessed under oxyfuel combustion conditions for the engine full-load curve from 1250 rpm to 3500 rpm in the absence of the CC, contrasting its outputs against the baseline conventional multi-cylinder CIE behavior. Secondly, the oxy-fuel powerplant load operation map is extended until system stability limits by modifying oxygen-fuel ratio and exhaust gas temperature for three engine speeds. Finally, the CC is designed and then coupled to the O2 generation unit, recycling water and excess of O2 from CC back to engine intake. In this regard, start of injection and recirculated water mass flow are swept in order to find out optimum operating point concerning the trade-off between powerplant performance and additional cooling power at 3500 rpm. Thereafter, the complete oxy-fuel carbon-capture layout model is enhanced and adapted for realistic application at laboratory scale and experimental proof of concept, following same trade-off philosophy. Although the final oxyfuel carbon-capture engine layout presents slight deterioration in performance if compared to the baseline conventional multi-cylinder CIE at 3500 rpm, this proposed novel concept may be still energy-efficient competitive as an emerging technology which might contribute for conception of zero-emission powerplant on commercial industrial scale. / Farias Da Silva, VH. (2024). Study of oxy-fuel combustion-based power plants with in-situ O2 production and carbon capture [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/207281

In this comparative study were four alternative windows researched to find the most suitable ones for replacement when renovating the Million Programme housing. The methodology in the study involves a combination of methods, using interviews with companies and tenants, email correspondence with people who contributed to the study, and observation of a multi-family building built during the Million Programme. The result shows that all alternatives are ideal, and the only difference is the insulation performance and the energy-efficiency, which can be said to be minimal. CO2-emissions and thus climate impact will be lowered regardless of the choice of windows for replacement based on the alternatives investigated. The interviews show that the customer/client decides the choice of window, which the construction companies pass on to the window-suppliers. The existing windows in the observed building showed low quality of energy efficiency, comfort and thus high climate impact. Finally, it is concluded that focus should be on low U-values and emissions rather than on costs which should not be the deciding factor. Buildings should be renovated within the renovation cycle developed by the Energimyndigheten and Boverket for impact on CO2-emissions and climate. Other measures for improvements are also proposed in this study.