Made available in DSpace on 2015-05-08T15:00:08Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2032932 bytes, checksum: 0a9d3a6d8d6a035afe37c1d839780916 (MD5) Previous issue date: 2010-08-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work presents the mathematical models used in the simulation of an absorption refrigeration system (SRA). Two models are presented: one for permanent simulation and another for simulation in transient regime. Balance equations of mass, concentration and energy are used together with other equations that complete the system of equations. The properties of ammonia and water solution are determined allowing estimating a variety of status points of the system. The implementation of the model was made in Engineering Equation Solver-EES. The model was validated using the results obtained in the test of a commercial refrigeration system of the ROBUR. / No presente trabalho apresentam-se os modelos matemáticos utilizados na simulação de um sistema de refrigeração por absorção (SRA). Dois modelos são apresentados: um para simulação em regime permanente e outro para simulação em regime transiente. Equações de balanço de massa, concentração e energia serão utilizadas juntamente com outras equações que fazem o fechamento do sistema de equações. As propriedades da solução de amônia e água serão determinadas, possibilitando o cálculo dos diversos pontos de estados do sistema em estudo. A implementação dos modelos foi feita no Engineering Equation Solver EES. A validação do modelo foi feita através dos dados obtidos no ensaio de um sistema de refrigeração comercial da ROBUR.

Orientador: Ricardo Alan Verdu Ramos / Banca: Emanuel Rocha Woiski / Banca: Eduardo Mirko Valenzuela Turdera / Resumo: Neste trabalho são realizadas análises termodinâmicas, termoeconômicas e econômicas aplicadas a uma usina de açúcar e álcool com processo de extração por difusão, envolvendo desde a configuração inicial de implantação da usina até a expansão para uma planta moderna de potência cujo principal objetivo é a produção de excedente de energia elétrica. São consideradas quatro situações: a configuração inicial da planta, definida como Caso 1, que opera visando gerar energia elétrica apenas para o próprio consumo e, também, vapor para o processo de produção de álcool; na seqüência tem-se a configuração, definida como Caso 2, onde o intuito é produzir o máximo de energia elétrica que o turbogerador pode fornecer e vapor para a produção de álcool e, também açúcar; na configuração seguinte, definida como Caso 3, é adicionada na planta uma turbina de condensação visando um melhor aproveitamento para a geração de energia elétrica; e, por fim, na última configuração, definida como Caso 4, é adicionada uma nova turbina de extração condensação e uma caldeira de alta pressão, priorizando a geração de energia elétrica / Abstract: In this work thermodynamic, thermoeconomic and economical analyses were accomplished in a sugar-alcohol factory with extraction process for diffusion, considering the initial configuration implanted until the expansion for a modern power plant whose main objective is the production of electric power surplus. Four situations were considered: the initial configuration of the plant, defined as Case 1, that operates generating electric power just for the own consumption and, also, steam for the alcohol production process; in sequence it was studied the configuration defined as Case 2, where the intention is to produce the maximum of electric power that the turbogenerator can supply and steam for the production of alcohol and, also, sugar; in the following configuration, defined as Case 3, it is added in the plant a condensation turbine for a better use in the electric power generation; and, finally, in the last configuration, defined as Case 4, it is added a new extractioncondensation turbine and a high pressure boiler, prioritizing the electric power generation / Mestre

Este trabalho apresenta uma avaliação comparativa de desempenho termodinâmico de sistemas térmicos em uma unidade industrial de fabricação de celulose e papel Kraft. Foram coletados dados de projeto e operação para o sistema atual de utilidades e de um novo sistema em fase de implantação. A análise exergética é utilizada como ferramenta de avaliação quantitativa e qualitativa para os principais componentes do sistema de cogeração de energia: caldeiras de força, caldeiras de recuperação química, turbinas e válvulas redutoras. Diferentes critérios de desempenho globais e relativos são determinados através de balanços simultâneos de energia e entropia (balanços exergéticos). As irreversibilidades ou entropia gerada nos sistemas são determinadas através da exergia destruída. Esta abordagem revela os principais pontos onde a energia é degradada em sua qualidade, indicando onde devem ser buscadas alternativas de otimização termoeconômica para um melhor aproveitamento dos recursos energéticos disponíveis. / This work presents a comparative evaluation from thermodynamic performance view of thermal systems in a Kraft pulp and paper mill. The design information and the data of the industrial operation were collected for the current utility system and for the new system that has been buit. The exergy analysis is applied as the quantitative and qualitative evaluation tool for the main energy conversion systems: power boilers, chemical recovery boiler, turbines and throttling valves. Different global and relatives performance criteria are estimated by simultaneous energy and entropy balances (exergy balances). The irreversibility or generated entropy in the systems is determined by the destroyed exergy. This approach reveals the places where energy quality is mainly degraded and shows where alternatives for optimization must be sought for a better use of the available energetic resources.

Offshore oil platforms are used for the exploitation and production of hydrocarbons and consist of a processing plant and a utility plant. The oil and gas industry operations are energy-intensive and, in the case of offshore platforms, the need to decrease energy consumption and reduce CO2 emissions has increased. In the oil and gas industry, the ISO 50001 standard promotes the implementation of energy management systems and proposes indicators based on energy. Interestingly, after several decades of knowledge of the concept of exergy, this has not been formally implemented in the programs and strategies of the oil and gas industry organizations. In this research, the implementation of the exergy method and the carbon capture and storage strategy for the assessment of the performance of a floating, production and storage offloading units FPSO is proposed. FPSO platforms and their processing and utility plants may have different configurations depending on, among others, the reservoir characteristics and production requirements. The possible configurations can therefore be numerous. In this sense, some operation scenarios based on different well-fluid compositions and operation modes are studied. The platform models are developed and simulated using the software Aspen HYSYS®. Results show that, on average, the reduction of 88.8% in CO2 emissions is penalized with a reduction in exergy efficiency of 1.7 points. Further, results allow a better understanding of exergy and environmental performance of the FPSO. / Plataformas de petróleo offshore são utilizadas para a exploração e produção de hidrocarbonetos e consistem em uma planta de processamento e uma planta de utilidade. As operações da indústria de petróleo e gás são de energia intensiva e, no caso de plataformas offshore, é necessário cada vez mais diminuir o consumo de energia e reduzir as emissões de CO2. Na indústria de petróleo e gás, a norma ISO 50001 promove a implementação de sistemas de gestão de energia e propõe indicadores baseados em energia. Entretanto, após várias décadas de conhecimento do conceito de exergia, este não foi formalmente implementado nos programas e estratégias das organizações da indústria de petróleo e gás. Neste trabalho, propõe-se a implementação da análise exergética e a estratégia de captura e armazenamento de carbono para a avaliação do desempenho de unidades flutuantes, de produção, de armazenamento e transferência FPSO. As plataformas FPSO e suas plantas de processamento e utilidade podem ter diferentes configurações dependendo, entre outras, das características do reservatório e dos requisitos de produção. As configurações possíveis podem, portanto, ser numerosas. Neste sentido, são estudados alguns cenários de operação baseados em diferentes composições dos fluidos do poço e em três modos de operação. Os modelos de plataforma são desenvolvidos e simulados usando o software Aspen HYSYS®. Os resultados mostram que, em média, a redução de 88,8% nas emissões de CO2 é penalizada com uma redução da eficiência exergética de 1,7 pontos. Além disso, os resultados permitem uma melhor compreensão da exergia e desempenho ambiental do FPSO.

Le captage et le stockage du dioxyde de carbone est la solution pour réduire les émissions de CO2 des grandes sources fixes. Le captage du CO2 par « Antisublimation » consiste à refroidir les fumées sous le point triple du CO2 qui passe alors directement de la phase vapeur à la phase solide. La variation de la concentration de CO2 induit une variation de la température d'environ 20 K à travers l'échangeur de chaleur. Son optimisation exergétique est une nécessité pour améliorer la séparation du CO2 et la performance énergétique du procédé.De nouvelles équations sont proposées pour calculer les propriétés thermodynamiques du CO2 à l'équilibre solide-vapeur qui sont jusqu'alors mal définies. Un diagramme psychrométrique CO2-N2 est développé pour représenter le glissement de température. L'étude du transfert de chaleur et de masse côté fumées nécessite la compréhension de l'antisublimation. La théorie classique de la nucléation est adoptée pour identifier les paramètres qui influent sur le transfert de masse et de la morphologie du givre. Une étude expérimentale qualitative et quantitative est effectuée pour étudier la formation de givre et sa dépendance vis-à-vis de la sursaturation et de la concentration du soluté. L'observation du CO2 solide sous 200x de grossissement prouve que l'antisublimation se fait par nucléation hétérogène. Un modèle CFD transitoire multi-phase et multi-composant est proposé pour simuler la formation du givre et sa croissance en fonction de la structure de l'échangeur et des conditions d'écoulement. / The carbon dioxide capture and storage is the solution to reduce CO2 emissions from large stationary sources. CO2 capture by "Antisublimation" consists in cooling flue gases under the CO2 triple point, which goes then directly from vapor to solid phase. The CO2 concentration variation induces a temperature variation of about 20 K through the heat exchanger. The exergy optimization of the heat exchanger is a necessity to improve the CO2 separation and the process energy performance.Since the CO2 properties under the triple point are not defined, new equations are proposed to calculate CO2 thermodynamic properties for solid-vapor equilibrium. A CO2-N2 psychrometric chart is developed to represent the flue-gas gliding temperature. The study of the flue–gas side heat and mass transfer requires antisublimation understanding. The classical nucleation theory is adopted to identify parameters that affect the mass transfer and frost morphology. A qualitative and quantitative experimental investigation is performed to study the frost formation and its dependence on the supersaturation and solute concentration. The solid CO2 observation under 200x magnification ratio proves that antisublimation occurs by heterogeneous nucleation. A CFD multiphase and multi-component transient model able to predict the frost formation and growth as a function of the heat-exchanger structure and flow conditions is proposed.

L’objectif de la thèse est de concevoir un design le plus optimisé possible d’une centrale à charbon pulvérisée fonctionnant en oxy-combustion. Une telle centrale intègre un système de production d’oxygène (ASU), une chaudière, un cycle électrogène, des équipements de dépollution ainsi qu’un système de purification et de compression du CO2 (CPU). Ainsi, dans un premier temps, la thèse portera sur la compréhension, l’analyse et la modélisation des différents procédés qui composent la chaîne d’une centrale fonctionnant en oxy-combustion. Ensuite, les performances et la configuration de la centrale seront optimisées de façon à réduire la destruction d’exergie tout s’assurant de la compétitivité économique de la solution ainsi obtenue. A l’issue de cette thèse, les origines des pertes exergétiques du système étudié et les schémas d’intégration permettant de maximiser les gains énergétique à l’échelle de la centrale seront identifiées. De plus, les stratégies de dépollution des fumées les plus adaptées seront définies et les nouveaux procédés intégrés seront évalués à la fois d’un point de vue technico-économiques et flexibilité. / The objective of the thesis is the conception of an optimized oxy-fired pulverized-coal power plant. Such a power plant is constituted of an oxygen production system (ASU), a boiler, power cycle, depollution equipments and a CO2 purification and compression system (CPU). After a first step consists in understanding, analyzing and modeling the different processes composing the oxy-combustion system; the work will focus on the optimization of the performances and the configuration of the power plant by minimizing exergy destructions while ensuring economic competitiveness of the obtained solution. At the end of the thesis, the origins of the exergetic losses in the system as well as the thermal integration scheme allowing the maximization of the energetic gains at power plant level will be identified. Additionally, the most adapted flue gas depollution strategies will be defined and the new integrated process schemes will be evaluated on both a techno-economic and flexibility basis.

Det råder koncensus bland klimatforskare världen över att en omställning från fossila bränslen till mer klimatneutrala alternativ måste ske i energiproduktionen om det ska gå att hejda den globala uppvärmningen. Ett alternativ för att lyckas med detta är att producera energin från förnybara energikällor som vind och solkraft. Detta är också något som utnyttjas i allt högre grad runt om i världen, men problem uppstår dock när en stor del av en regions andel av energiproduktionen kommer från dessa källor. Det skapas en prisvolatilitet på marknaden, med priser som varierar lika mycket som vindstyrkan eller solinstrålningen. Ibland sjunker priserna så lågt att det är svårt att nå en lönsamhet för kraftverken. För att komma till bukt med denna obalans på energimarknaden kommer det att behöva byggas ett energilagringssystem som lagrar energin de förnybara källorna producerar. Ett alternativ för att lagra energi är att utvinna vätgas genom elektrolys när priserna på elmarknaden är låga för att sälja detta till olika aktörer. Tanken är att prisdalar ska jämnas ut om en överproduktion av el motverkas av en ökande elförbrukning genom vätgasframställning. På samma sätt jämnas pristopparna ut genom att upphöra med denna framställning när elproduktionen minskar. De aktörer som kan tänkas använda den producerade vätgasen kan vara allt från förbrukare inom industrin, vätgasbilar i transportsektorn, stationära bränsleceller för reservkraftverk, omvandling av koldioxid till biogas med hjälp av vätgas och konvertering av oljeeldade värmepannor. Vätgas är en skrymmande gas vid normalt tryck och temperatur, varför lagring måste ske i högt tryck eller i vätskefas. Detta göra att lagring och transport är två av de kostsammaste aspekterna i vätgashanteringen. Elpriset är också en stor kostnadsdrivare när vätgas framställs genom elektrolys. Dock kan en del av kostnaden för inköp av elenergi till en sådan här elektrolysanläggning undvikas om den placeras inom ett så kallat icke konscessionspliktigt nät, där ingen överföringsavgift behöver betalas. Exempel på sådana områden är vindkraftsparken på berget Uljabuouda utanför Arjeplog och fjärrvärmeverket på Hedensbyn i Skellefteå. Det huvudsakliga syftet med denna rapport har varit att undersöka om det är ekonomiskt försvarbart att lagra energi i form av vätgas genom elektrolysframställning. För att undersöka detta valdes att placera två tänkta elektrolysörer på Uljabuouda och Hedensbyn tillsammans med en jämförelseanläggning i Arjeplogs samhälle. Dessutom valdes två olika storlekar på elektrolysörerna, en som producerar 150 Nm3 vätgas i timmen, kallad C150, och en annan som producerar 300 Nm3, kallad C300. Förutom det huvudsakliga syftet har rapporten undersökt vilket snittpris på el det varit under de senaste fyra åren. Det presenteras också några beräkningar för olika marknadsaktörers möjligheter att använda vätgas. Undersökningens resultat Lönsamheten för elektrolysören styrs i första hand av om all vätgas som produceras kan säljas, givet att anläggningen placeras inom icke koncessionspliktigt nät. Placeras den utanför sagda område är lönsamheten betydligt sämre. Placering av elektrolysören på Hedensbyn ger lite bättre ekonomiskt resultat och kortare återbetalningstid i jämförelse med en placering på Uljabuouda. Det här beror till största del på de stordriftsfördelar som antas erhållas i anslutning till ett bemannat fjärrvärmeverk. Återbetalningstiden i år för en elektrolysör som producerar 150 Nm3/h, med en drifttid på 4000 h/år och ett försäljningspris för vätgasen på 90 kr/kg är följandeUljabuouda: 11,3 år Arjeplog: 14,4 år Hedensbyn: 10,8 år Återbetalningstiden i år för en elektrolysör som producerar 300 Nm3/h, med en drifttid på 4000 h/år och ett försäljningspris för vätgasen på 90 kr/kg är följandeUljabuouda: 7,92 år Arjeplog: 9,25 år Hedensbyn: 7,75 år Det är osäkert om det går få tillstånd att bygga en elektrolysör på Uljabuouda. Detta gör att det kanske inte ens är lönt att överväga byggnation av en elektrolysör på detta ställe. De senaste fyra åren har snittpriset på el har varit 274 kr/MWh. Vid ett så lågt elpris kan vindkraftverk få problem med lönsamhet för sin elproduktion. Marknadsundersökningen visar att marknaden för vätgas i Västerbotten och Norrbotten inte är speciellt stor i nuläget. Den kan dock komma att växa. Biltestverksamheten i Arjeplog kan inom en snar framtid förbruka en väsentlig del av det som en elektrolysör i storlek C150 producerar. Fjärrvärmeverket på Hedensbyn är också en möjlig förbrukare av vätgas i sina uppstartsbrännare. / There is a consensus amongst climate scientists around the world that a shift from fossil fuels to more climate-neutral alternatives must take place in the energy production in order to cope with global warming. One way to succeed with this is to produce energy from renewable sources such as wind and solar power. This is also something that is increasingly being utilized around the world, but problems arise when a large part of a region's share of energy production comes from these sources. There can be price volatility in the market, with prices that vary as much as wind or solar radiation. Sometimes prices drop so low that it is difficult to achieve profitability for power plants. In order to overcome this imbalance in the energy market, an energy storage system will need to be built that stores the energy the renewable sources produce. An alternative to storing energy is to extract hydrogen through electrolysis when prices in the electricity market are low to sell this to different players. The idea is that price valleys will be leveled out if an overproduction of electricity is counteracted by increasing electricity consumption through hydrogen production. Similarly, pricing peaks are leveled by ending this production when power generation decreases. The operators who may use the hydrogen produced may range from industrial users, hydrogen vehicles in the transport sector, stationary fuel cells for reserve power plants, conversion of carbon dioxide to biogas by hydrogen and conversion of oil-fired boilers. Hydrogen is a bulky gas at normal pressure and temperature, so storage must take place in high pressure or in liquid phase. This means that storage and transportation are two of the most expensive aspects of hydropower management. Electricity price is also a major cost driver when hydrogen is produced by electrolysis. However, part of the cost of purchasing electricity for such an electrolysis plant can be avoided if it is placed within a so-called non-licensed network, where no transfer fee is required. Examples of such areas are the wind farm on the Uljabuouda mountain outside Arjeplog and the district heating plant at Hedensbyn in Skellefteå. The main purpose of this report has been to investigate whether it is economically justifiable to store energy in the form of hydrogen through electrolysis production. To investigate this, it was decided to place two thought electrolysers on Uljabuouda and Hedensbyn together with a comparison facility in Arjeplog's society. In addition, two different sizes were selected on the electrolysis tubes, one that produces 150 Nm3 hydrogen per hour, called C150, and another that produces 300 Nm3, called the C300. In addition to the main purpose, the report has examined the average price of electricity for the last four years. It also presents some estimates for the potential of various market participants to use hydrogen. Survey results: The profitability of the electrolyzer is primarily governed by the fact that all hydrogen produced can be sold, given that the plant is placed within non-concessionary networks. Placed outside the stated area, profitability is significantly reduced. Placement of the electrolyzer on Hedensbyn gives a little better financial performance and a shorter payback time compared to a location on Uljabuouda. This is largely due to the economies of scale assumed to be obtained in connection with a manned district heating plant. The payback time in figures for an electrolyzer that produces 150 Nm3/h, with a running time of 4000 h/year and a sales price of 90 kr/kg of hydrogen is the followingUljabuouda: 11,3 år Arjeplog: 14,4 år Hedensbyn: 10,8 år The payback time in figures for an electrolyzer producing 300 Nm3 / h, with a running time of 4000 h / year and a sales price of 90 kr / kg of hydrogen is the followingUljabuouda: 7,92 år Arjeplog: 9,25 år Hedensbyn: 7,75 år It is uncertain whether permission is being given to build an electrolyzer on Uljabuouda. This may make the construction of an electrolytic tube there not even worth to consider. In the past four years, the average electricity price has been 274 kr / MWh. This is a low electricity price due to overproduction of electricity. At such a low electricity price, wind turbines can have problems with profitability for their production. The market survey shows that the market for hydrogen in Västerbotten and Norrbotten is not particularly high at present. However, it may grow. The car test business in Arjeplog can in the near future consume an essential part of what an electrolytic tube in size C150 produces. The district heating plant at Hedensbyn is also a potential hydrogen source in its boot burner.

Copper is an essential metal in today’s economy, due to its superior electrical and thermal conductivities, alloying properties, and chemical uses. Most copper is produced viamining and refining, and most copper is found in the earth’s crust as chalcopyrite, CuFeS2. Typically, chalcopyrite is concentrated and fed to a high temperature pyrometallurgical process which produces >99.99% purity copper cathodes. Recently, Freeport-McMoRan Inc. has implemented a hydrometallurgical autoclave-leaching process that takes chalcopyrite concentrate and produces copper cathodes. It is imperative that these pyrometallurgical and hydrometallurgical processes be modeled and compared so that the extraction industry can best decide which technology to apply in the future. This work presents transient, reduced-order models for the comparison of the two processes using exergy balances. Exergy is typically thought of as the maximum work extractable from a system as it spontaneously reacts to the state of the surrounding environment; for extractive processes, it is also helpful to think of exergy as the minimum work required to effect a concentration, e.g. of copper. Exergy balances are thus similar to first law balances, but they comment on the location and magnitude of usefulenergy flows, instead of energy flows in general. For the baseline case, this work found that the pyrometallurgical process up to 99.5% copper anode stored 54% of the fed exergy in product, lost 20% of the fed exergy, and destroyed the remaining 26%. In contrast, the hydrometallurgical process up to 30 grams-per-liter copper pregnant-leach-solution stored 5% of the fed exergy in product, lost 9% of the fed exergy, and destroyed the remaining 86%. The effects of process variations are also looked at. It is recommended that this work be incorporated in whole-plant exergy balances to more precisely examine the tradeoffs between the pyrometallurgical and hydrometallurgical routes of copper extraction from chalcopyrite concentrates.

<p>U okviru doktorske disertacije predstavljen je<br />razvoj hibridnog modela za ocenjivanje životnog ciklusa<br />proizvoda i procesa. Razvoj hibridnog modela se ogleda<br />kroz unapređenje postojećeg metodskog okvira LCA, te je<br />stoga uključio razvoj svih faza LCA, a koje obuhvataju<br />definisanje cilja i predmeta, inventar životnog ciklusa,<br />ocenjivanje uticaja životnog ciklusa i interpretaciju<br />rezultata. Najznačajnija unapređenja su sprovedena u<br />okviru faza inventara životnog ciklusa i ocenjivanja uticaja<br />životnog ciklusa. Izmene koje se odnose na način<br />prikupljanja podataka, su razvijene zbog uključivanja<br />parametara potrebnih za izračunavanje vrednosti sadržaja<br />eksergije tokova. Unapređenje faze ocenjivanja uticaja<br />životnog ciklusa se ogleda kroz razvoj originalnog pristupa<br />za izračunavanje ukupne potro&scaron;nje eksergije, kroz<br />uključivanje dodatne kategorije uticaja, razvijanje<br />indikatora kategorije uticaja i razvijanje pristupa za<br />izračunavanje karakterizacionih faktora. Sprovedena je i<br />analiza postojećih LCIA metoda, radi izbora adekvatnog<br />metoda u koji će biti uključena dodatna kategorija uticaja,<br />kao i indikator kategorije uticaja, koji zajedno opisuju<br />ukupnu potro&scaron;nju eksergije tokom čitavog životnog<br />ciklusa. Takođe, prilikom razvoja kategorije uticaja su<br />po&scaron;tovani određeni kriterijumi, koje ona mora da zadovolji<br />da bi mogla biti adekvatno uključena u odabrani LCIA<br />metod. Pored toga, bitan deo unapređenja ocenjivanja<br />uticaja životnog ciklusa, leži u razvoju proračuna<br />karakterizacionih faktora. Razvijena dodatna kategorija<br />uticaja nazvana je Ukupna potro&scaron;nja eksergije - UPE, a<br />izražava se preko indikatora MJex. LCIA metod koji je<br />odabran na osnovu SWOT analize u koji je ova dodatna<br />kategorija uticaja uključena je CML metod. Postavljeni<br />hibridni metodski okvir posmatra kompletan životni ciklus,<br />ali i svaki od jediničnih procesa koji uključuju elementarne<br />tokove, odnosno tokove uzete iz prirodnog sistema bez<br />dodatne obrade, kao i tokove proizvoda, odnosno tokovekoji su na neki način izmenjeni od strane pojedinih<br />antropogenih sistema. Izračunavanje sadržaja eksergije i<br />karakterizacionih faktora je sprovedeno kako za<br />elementarne tokove tako i za tokove proizvoda.<br />Funkcionalnost i praktična primenljivost razvijenog<br />hibridnog modela je verifikovana na dva primera, koji su<br />obuvatili proizvodnju laminatnog parketa i međusobnu<br />komparaciju hibridnih baznih predajničkih stanica i<br />konvencionalnih baznih predajničkih stanica. Dobijeni<br />rezultati daju jednu zaista detaljniju i &scaron;iru sliku mehanizma<br />nastanka i izvora negativnih uticaja tokom životnog ciklusa<br />posmatranih industrijskih sistema. Time je potvrđena<br />njegovu praktična primenljivost, kao i ukupni cilj<br />istraživanja. Rezultati istraživanja realizovani u okviru<br />doktorske disertacije, u op&scaron;tem smislu, daju doprinos<br />stvaranju osnove za izdradnju puta ka razvoju i proizvodnji<br />održivih proizvoda i procesa. Razvijeni hibridni model za<br />ocenjivanje životnog ciklusa proizvoda i procesa pruža<br />dodatne informacije, koje mogu biti korisne u procesu<br />dono&scaron;enja odluka na svim nivoima, kako u industriji tako i<br />u državnim institucijama.</p> / <p>This PhD thesis presented the development of a<br />hybrid model for life cycle assessment of products and<br />processes. The development of a hybrid model includes the<br />improvement of the existing methodological LCA<br />framework, and therefore of all phases of the LCA:<br />definition of goal and scope, inventory analysis, life cycle<br />impact assessment and interpretation. The most significant<br />improvements have been made within the inventory<br />analysis and life cycle impact assessment phases.<br />Improvement have been made in relation to the method of<br />data collection, due to the inclusion of parameters for<br />calculation of the exergy content of in- and output flows.<br />Improvement of the life cycle impact assessment phase is<br />reflected through the development of original approach for<br />calculating the total consumption of exergy, through the<br />inclusion of additional impact category, development of<br />indicator for impact category and development of method<br />for calculation of characterization factors. The analysis of<br />existing LCIA methods was performed, in order to choose<br />the appropriate method that will incorporate this additional<br />impact category, as well as an impact category indicator,<br />which together should describe the total consumption of<br />exergy throughout the entire life cycle. Further,<br />development of this impact category have been complied<br />with certain criteria which it must meet in order to be<br />properly incorporated in the chosen LCIA method. Besides<br />this, an important part of improvement of the life cycle<br />impact assessment is the development of method for<br />calculation of characterization factors. Developed<br />additional impact category is named Total exergy<br />consumption, and it&#39;s expressed through indicator of MJex.<br />LCIA method that is chosen based on the performed<br />SWOT analysis and which incorporated this additional<br />impact category is CML method. Developed hybrid<br />methodological framework takes into account the entire life<br />cycle, and each of the unit processes that involves<br />elementary flows (flows taken from the natural system<br />without any further processing), as well as product flows(flows that are in some way altered by certain<br />anthropogenic system). Calculation of exergy and<br />characterization factors was performed for both elementary<br />and product flows.<br />Functionality and practical applicability of the<br />developed hybrid model was verified through two case<br />studies, which are the production of laminate parquet<br />flooring and comparison of hybrid base transceiver stations<br />and conventional base transceiver stations. The obtained<br />results provided more detailed and more broader insight of<br />the mechanism of the generation and source of negative<br />impacts throughout the life cycle of observed industrial<br />systems. Thus, the practical applicability of the developed<br />hybrid model and goal of the research have been<br />confirmed. The results of the research contribute to<br />creation of the foundation for designing a path towards<br />development and manufacturing of sustainable products<br />and processes. The developed hybrid model for the life<br />cycle assessment of products and processes provides<br />additional information that may be useful in decisionmaking<br />process at all levels, within both industry and<br />government institutions.</p>

The change in climate as a consequence of anthropogenic activities is a subject ofmajor concerns. In order to reduce the amount of greenhouse gas emissions inthe atmosphere, the utilization of renewable, fossil-free power generationapplications becomes inevitable. Geothermal and solar energy play a major rolein covering the increased demand for renewable energy sources of today’s andfuture’s society. A special focus hereby lies on the Concentrating Solar Powertechnologies and different geothermal concepts. The costs for producingelectricity through Concentrating Solar Power and therefore Parabolic Trough Collectorsas well as geothermal conversion technologies are still comparatively high. Inorder to minimize these expenses and maximize the cycle’s efficiency, thepossible synergies of a hybridization of these two technologies becomeapparent. This thesis therefore investigates the thermodynamic and economicbenefits and drawbacks of this combination from a global perspective. For that,a Parabolic Trough Collector system is combined with the geothermal conversionconcepts of Direct Steam, Single and Double Flash, Organic Rankine as well asKalina Cycles. The solar integrations under investigation are Superheat,Preheat and Superheat &amp; Reheat of the geothermal fluid. The thermodynamicanalysis focuses on the thermal and utilization efficiencies, as well as therequired Parabolic Trough Collector area. The results indicate that in the caseof the Superheat and Superheat &amp; Reheat setup, the thermal efficiency canbe improved for all geothermal concepts in comparison to their correspondinggeothermal stand-alone case. The Preheat cases, with the major contributionfrom solar energy, are not able to improve the cycle’s thermal efficiencyrelative to the reference setup. From an exergy perspective the findings varysignificantly depending on the applied boundary conditions. Still, almost allcases were able to improve the cycle’s performance compared to the referencecase. For the economic evaluation, the capital investment costs and thelevelized costs of electricity are studied. The capital costs increasesignificantly when adding solar energy to the geothermal cycle. The levelizedelectricity costs could not be lowered for any hybridization case compared tothe reference only-geothermal configurations. The prices vary between20.04 €/MWh and 373.42 €/MWh. When conducting a sensitivity analysison the solar system price and the annual mean irradiance, the Kalina Superheatand Superheat &amp; Reheat, as well as the Organic Rankine Preheathybridizations become cost competitive relative to the reference cases.Concluding, it is important to remark, that even if the hybridization of the ParabolicTrough and the different geothermal concepts makes sense from a thermodynamicperspective, the decisive levelized costs of electricity could not be improved.It is, however, possible that these costs can be further reduced under speciallocal conditions, making the addition of Parabolic Trough solar heat tospecific geothermal concepts favorable.