Nous étudions la distillation extractive continue de mélanges azéotropiques à temperature de bulle minimale avec un entraineur lourd (classe 1.0-1a) avec comme exemples les mélanges acétone-méthanol avec l’eau et DIPE-IPA avec le 2-méthoxyethanol. Le procédé inclut les colonnes de distillation extractive et de régénération de l’entraineur en boucle ouverte et en boucle fermée. Une première stratégie d’optimisation consiste à minimiser la fonction objectif OF en cherchant les valeurs optimales du débit d’entraineur FE, les positions des alimentations en entraineur et en mélange NFE, NFAB, NFReg, les taux de reflux R1, R2 et les débits de distillat de chaque colonne D1, D2. OF décrit la demande en énergie par quantité de distillat et tient compte des différences de prix entre les utilités chaudes et froides et entre les deux produits. La deuxième stratégie est une optimisation multiobjectif qui minimise OF, le coût total annualisé (TAC) et maximise deux nouveaux indicateurs thermodynamiques d’efficacité de séparation extractive totale Eext et par plateau eext. Ils décrivent la capacité de la section extractive à séparer le produit entre le haut et le bas de la section extractive. L’analyse thermodynamique des réseaux de courbes de résidu ternaires RCM et des courbes d’isovolatilité montre l’intérêt de réduire la pression opératoire dans la colonne extractive pour les séparations de mélanges 1.0-1a. Une pression réduite diminue la quantité minimale d’entraineur et accroît la volatilité relative du mélange binaire azéotropique dans la région d’opération de la colonne extractive. Cela permet d’utiliser un taux de reflux plus faible et diminue la demande énergétique. La première stratégie d’optimisation est conduite avec des contraintes sur la pureté des produits avec les algorithmes SQP dans les simulateurs Aspen Plus ou Prosim Plus en boucle ouverte. Les variables continues optimisées sont : R1, R2 et FE (étape 1). Une étude de sensibilité permet de trouver les valeurs de D1, D2 (étape 2) et NFE, NFAB, NFReg (étape 3), tandis l’étape 1 est faite pour chaque jeu de variables discrètes. Enfin le procédé est resimulé en boucle fermée et TAC, Eext et eext sont calculés (étape 4). Les bilans matières expliquent l’interdépendance des débits de distillats et des puretés des produits. Cette optimisation permet de concevoir des procédés avec des gains proches de 20% en énergie et en coût. Les nouveaux procédés montrent une amélioration des indicateurs Eext et eext. Afin d’évaluer l’influence de Eext et eext sur la solution optimale, la seconde optimisation multiobjectif est conduite. L’algorithme génétique est peu sensible à l’initialisation, permet d’optimiser les variables discrètes N1, N2 et utilise directement le shéma de procédé en boucle fermée. L’analyse du front de Pareto des solutions met en évidence l’effet de FE/F et R1 sur TAC et Eext. Il existe un Eext maximum (resp. R1 minimum) pour un R1 donné (resp. Eext). Il existe aussi un indicateur optimal Eext,opt pour le procédé optimal avec le plus faible TAC. Eext,opt ne peut pas être utilisé comme seule fonction objectif d’optimisation mais en complément des autres fonctions OF et TAC. L’analyse des réseaux de profils de composition extractive explique la frontière du front de Pareto et pourquoi Eext augmente lorsque FE diminue et R1 augmente, le tout en lien avec le nombre d’étage. Visant à réduire encore TAC et la demande énergétique nous étudions des procédés avec intégration énergétique double effet (TEHI) ou avec des pompes à chaleur (MHP). En TEHI, un nouveau schéma avec une intégration énergétique partielle PHI réduit le plus la demande énergétique. En MHP, la recompression partielle des vapeurs VRC et bottom flash partiel BF améliorent les performances de 60% et 40% respectivement. Au final, le procédé PHI est le moins coûteux tandis que la recompression totale des vapeurs est la moins énergivore. / We study the continuous extractive distillation of minimum boiling azeotropic mixtures with a heavy entrainer (class 1.0-1a) for the acetone-methanol with water and DIPE-IPA with 2-methoxyethanol systems. The process includes both the extractive and the regeneration columns in open loop flowsheet and closed loop flowsheet where the solvent is recycled to the first column. The first optimization strategy minimizes OF and seeks suitable values of the entrainer flowrate FE, entrainer and azeotrope feed locations NFE, NFAB, NFReg, reflux ratios R1, R2 and both distillates D1, D2. OF describes the energy demand at the reboiler and condenser in both columns per product flow rate. It accounts for the price differences in heating and cooling energy and in product sales. The second strategy relies upon the use of a multi-objective genetic algorithm that minimizes OF, total annualized cost (TAC) and maximizes two novel extractive thermodynamic efficiency indicators: total Eext and per tray eext. They describe the ability of the extractive section to discriminate the product between the top and to bottom of the extractive section. Thermodynamic insight from the analysis of the ternary RCM and isovolatility curves shows the benefit of lowering the operating pressure of the extractive column for 1.0-1a class separations. A lower pressure reduces the minimal amount of entrainer and increases the relative volatility of original azeotropic mixture for the composition in the distillation region where the extractive column operates, leading to the decrease of the minimal reflux ratio and energy consumption. The first optimization strategy is conducted in four steps under distillation purity specifications: Aspen Plus or Prosim Plus simulator built-in SQP method is used for the optimization of the continuous variables: R1, R2 and FE by minimizing OF in open loop flowsheet (step 1). Then, a sensitivity analysis is performed to find optimal values of D1, D2 (step 2) and NFE, NFAB, NFReg (step 3), while step 1 is done for each set of discrete variables. Finally the design is simulated in closed loop flowsheet, and we calculate TAC and Eext and eext (step 4). We also derive from mass balance the non-linear relationships between the two distillates and how they relate product purities and recoveries. The results show that double digit savings can be achieved over designs published in the literature thanks to the improving of Eext and eext. Then, we study the influence of the Eext and eext on the optimal solution, and we run the second multiobjective optimization strategy. The genetic algorithm is usually not sensitive to initialization. It allows finding optimal total tray numbers N1, N2 values and is directly used with the closed loop flow sheet. Within Pareto front, the effects of main variables FE/F and R1 on TAC and Eext are shown. There is a maximum Eext (resp. minimum R1) for a given R1 (resp. Eext). There exists an optimal efficiency indicator Eext,opt which corresponds to the optimal design with the lowest TAC. Eext,opt can be used as a complementary criterion for the evaluation of different designs. Through the analysis of extractive profile map, we explain why Eext increases following the decrease of FE and the increase of R1 and we relate them to the tray numbers. With the sake of further savings of TAC and increase of the environmental performance, double-effect heat integration (TEHI) and mechanical heat pump (MHP) techniques are studied. In TEHI, we propose a novel optimal partial HI process aiming at the most energy saving. In MHP, we propose the partial VRC and partial BF heat pump processes for which the coefficients of performance increase by 60% and 40%. Overall, optimal partial HI process is preferred from the economical view while full VRC is the choice from the environmental perspective.

Les microalgues sont de plus en plus regardées pour leurs potentiels énergétiques et leurs nombreuses applications. Mais les systèmes de production actuels, que se soit les systèmes dits ouvert comme les bassins ou les systèmes fermés, appelés photobioréacteurs, sont très énergivores et pas assez productifs. Cette thèse propose un nouveau concept de photobioréacteur, composé d'un airlift et d'une plaque mince. Le photobioréacteur est caractérisé expérimentalement et est modélisé sous plusieurs aspects. L'hydrodynamique du système est modélisée pour prédire le comportement des fluides dans le système. Les phénomènes de transferts de masse sont modélisés par le modèle des deux films. La modélisation permet de connaitre l'apport minimum nécessaire en dioxyde de carbone pour la culture des microalgues et permet d'évaluer la concentration en oxygène dissous dans le photobioréacteur. Elle permet aussi d'évaluer son élimination par le système, l'oxygène étant inhibant pour la culture. Les phénomènes de transferts de chaleur sont aussi modélisés, permettant de connaitre l'impact des différents paramètres (ensoleillement, température de l'air ambiant) sur la température de culture. Ces différents modèles sont rassemblés en un modèle global qui est comparé aux résultats expérimentaux de culture d'algues. Le modèle global est ensuite utilisé dans un contexte plus complexe : l'intégration des plaques minces du photobioréacteur aux parois d'un bâtiment. Le modèle global permettra d'étudier l'effet les différentes orientations (Nord, Sud, Est, Ouest en vertical sur les façades et à l'horizontal sur les toits) sur les températures et productivité du système. La consommation d'énergie de la culture est optimisée grâce au modèle. A la suite de cette optimisation, certaines perspectives sur l'intégration énergétique d'un tel système sont proposées. / Microalgae are more and more studied for their energy potential and various applications. However, the actual production processes (open and closed photobioreactor) use a lot of energy and aren't productive enough. This thesis presents a novel process of microalgae culture, with an airlift system coupled to a thin plate. The photobioreactor is experimentally characterized and modeled for many aspects. Hydrodynamics of the system is modeled to predict the fluid behavior in the system. Mass transfers are modeled using the two film model. The model allows knowing minimum carbon needs for microalgae culture. It also allows evaluating dissolved oxygen concentration in the photobioreactor and its elimination efficiency. Oxygen is inhibiting the culture at high concentration. Heat transfers are also modeled, allowing to know climate parameters impact (sunshine, ambient air temperature) on culture temperature. All models are assembled in a global model. This model is compared to microalgae culture experimental results. Finally, the global model is used to study a more complex system: culture thin plates are integrated on the walls of buildings. Global model allow studying different orientation effects on temperature and productivity of the system. Culture is optimized for energy consumption and some perspectives on energy integration of such a system are proposed.

This thesis assessed the life-cycle environmental impact of a lithium-ion battery pack intended for energy storage applications. A model of the battery pack was made in the life-cycle assessment-tool, openLCA. The environmental impact assessment was conducted with the life-cycle impact assessment methods recommended in the Batteries Product Environmental Footprint Category Rules adopted by the European Commission (2016). The findings in this study showed that the most important parameter in the cradle-to-grave assessment was the use-stage losses, which can be reduced by using electricity grids with high sharesof renewable energy or by increase the round-trip efficiency of the battery system. However, for the cradle-to-gate assessment, five impact categories were found to be relevant. These categories were: climate change, acidification, fossil resource use, resource use (minerals and metals) and particulate matter. Furthermore, within these impact categories, four materials contributed to more than 65 % of all impact. These key materials were; nickel, aluminium, cobalt and graphite. Therefore, a recommendation to battery manufacturers is to prioritise sourcing these four key materials from sustainable suppliers to reduce the overall cradle-to-gate environmental impact. Lastly, by integrating recycling of the battery pack in the end-of-life-stage, it was possibleto achieve a net reduction of 9-20 % of the cradle-to-grave climate change, acidification and fossil resource use compared to not including recycling. Therefore, the development of efficient and large-scale recycling will likely play a major role in reducing the environmental impact from lithium-ion batteries in the future.

[pt] O biodiesel é um biocombustível produzido tipicamente a partir da transesterificação e/ou esterificação, de óleos vegetais (ex. soja e dendê) que é constituído por diferentes tipos de ácidos graxos como, por exemplo, ácido oleico, linoleico, linolênico em composições distintas. Todavia, entre os artigos encontrados na literatura que abordam simulações e intensificação de processos industriais na produção do biodiesel, a composição química do óleo é simplificada, reduzindo-se ao triglicerídeo de maior concentração. A fim de analisar a intensificação do processo de obtenção de biodiesel, a partir do óleo de soja, utilizando destilação reativa, inicialmente, foi realizado a comparação das propriedades do biodiesel, como densidade, viscosidade e composição, produzido via catálise homogênea e heterogênea, considerando-se a composição química total do óleo de soja e considerando apenas o triglicerídeo majoritário, composto por uma molécula de ácido oleio e duas de ácido linoleico. A análise confirmou que não há alteração significativa nos resultados em substituir a composição do biodiesel por uma fração única de triglicerídeos, devido à proximidade de propriedades físico-químicas. Visto isto, o desenvolvimento da simulação e intensificação do processo foi desenvolvido a partir do componente majoritário no óleo de soja. Considerando o déficit de informações completas relacionando os estudos de composição, destilação reativa, integração energética e avaliação econômica, a tese complementa uma metodologia para simular a produção do biodiesel via catálise homogênea e heterogênea, utilizando a destilação reativa (DR), integração energética e considerando a viabilidade financeira de todos os fluxogramas estudados. Nas simulações desenvolvidas resultaram um melhor aproveitamento da energia presente nos correntes quentes disponíveis, e assim reduzindo-se o investimento em utilidades. Concluiu-se que ao empregar a destilação reativa, para catálise homogênea e heterogênea, há energia a ser economizada, em torno de 30 a 48 por cento, ou seja, há disponibilidade de modificação no processo para que ocorra um melhor aproveitamento e economia de energia. A partir disto, empregou-se a integração energética, utilizando o sistema de reaproveitamento energético, obtendo um melhor cenário para o estudo energético proporcionando uma economia de 70 por cento e 65,8 por cento de energia nos processos homogêneo e heterogêneo, respectivamente. Quanto à viabilidade econômica, considerou-se a capacidade do processo com vida útil de 15 anos e as simulações indicaram rendimentos positivos e sugere-se serem viáveis economicamente. Porém, ao empregar a destilação reativa com intensificação do processo, a redução de gastos energéticos e financeiros com o catalisador heterogêneo se mostrou ser a melhor opção energeticamente e economicamente. Comparando o sistema com gastos, o inicial homogêneo, com o econômico, dito anteriormente, a economia de energia das utilidades foi em torno de 80 por cento e a diferença no valor presente líquido (VPL) de 744.089,84 de dólares. O resultado mostrou que o investimento em mais trocadores de calor de correntes de processo somados à redução de equipamentos da via por catalise heterogênea permitiu alcançar uma relação de custo alternativa mais atraente que o processo tradicional via catálise homogênea ainda que o custo do catalisador seja maior no caso heterogêneo. / [en] Biodiesel is a biofuel typically produced from transesterification and/or esterification of vegetable oils (eg soy and palm oil) which is made up of different types of fatty acids such as, for example, oleic, linoleic, linolenic acid in different compositions. However, among the articles found in the literature that address simulations and intensification of industrial processes in the production of biodiesel, the chemical composition of the oil is simplified, reducing it to the highest concentration triglyceride. In order to analyze the intensification of the process of obtaining biodiesel from soybean oil, using reactive distillation, initially, a comparison of the properties of biodiesel, such as density, viscosity and composition, produced via homogeneous and heterogeneous catalysis was performed, considering - the total chemical composition of soybean oil and considering only the major triglyceride, composed of one molecule of oleic acid and two of linoleic acid. The analysis confirmed that there is no significant change in the results in replacing the biodiesel composition with a single fraction of triglycerides, due to the proximity of physicochemical properties. In view of this, the development of simulation and process intensification was developed from the major component in soybean oil. Considering the lack of complete information relating composition studies, reactive distillation, energy integration and economic evaluation, the thesis complements a methodology to simulate the production of biodiesel via homogeneous and heterogeneous catalysis, using reactive distillation (DR), energy integration and considering the financial feasibility of all studied flowcharts. The simulations developed resulted in a better use of the energy present in the available hot currents, thus reducing the investment in utilities. It was concluded that when using reactive distillation, for homogeneous and heterogeneous catalysis, there is energy to be saved, around 30 to 48 percent, that is, there is availability of modification in the process so that there is a better use and energy saving. From this, energy integration was used, using the energy reuse system, obtaining a better scenario for the energy study, providing savings of 70 percent and 65.8 percent of energy in homogeneous and heterogeneous processes, respectively. As for the economic feasibility, it was considered the capacity of the process with a useful life of 15 years and the simulations indicated positive yields and are suggested to be economically viable. However, by employing reactive distillation with process intensification, the reduction of energy and financial costs with the heterogeneous catalyst proved to be the best option energetically and economically. Comparing the system with expenses, the initial homogeneous, with the economic, mentioned above, the energy savings of the utilities was around 80 percent and the difference in the net present value (NPV) of 744,089.84 dollars. The result showed that the investment in more process current heat exchangers, added to the reduction of equipment in the heterogeneous catalysis path, allowed to reach a more attractive alternative cost ratio than the traditional process via homogeneous catalysis, even though the cost of the catalyst is higher in the heterogeneous case.

Without decarbonizing cities energy and climate objectives cannot be achieved as cities account for approximately two thirds of energy consumption and emissions. This goal of decarbonizing cities has to be facilitated by promoting net-zero/positive energy buildings and districts and replicating them, driving cities towards sustainability goals. Many projects in smart cities demonstrate novel and groundbreaking low-carbon solutions in demonstration and lighthouse projects. However, as the historical, geographic, political, social and economic context of urban areas vary greatly, it is not always easy to repeat the solution in another city or even district. It is therefore important to look for the opportunities to scale up or repeat successful pilots. The purpose of this paper is to explore common trends in technologies and replication strategies for positive energy buildings or districts in smart city projects, based on the practical experience from a case study in Leipzig—one of the lighthouse cities in the project SPARCS. One of the key findings the paper has proven is the necessity of a profound replication modelling to deepen the understanding of upscaling processes. Three models analyzed in this article are able to provide a multidimensional representation of the solution to be replicated.

Energy consumption rates have been dramatically increasing on a global scale within the last few decades. A significant role in this increase is subjected by the recent high temperature levels especially at summer time which caused a rapid increase in the air conditioning demands. Such phenomena can be clearly observed in developing countries, especially those in hot climate regions, where people depend mainly on conventional air conditioning systems. These systems often show poor performance and thus negatively impact the environment which in turn contributes to global warming phenomena. In recent years, the demand for urban or district cooling technologies and networks has been increasing significantly as an alternative to conventional systems due to their higher efficiency and improved ecological impact. However, to obtain an efficient design for district cooling systems is a complex task that requires considering a wide range of cooling technologies, various network layout configuration possibilities, and several energy resources to be integrated. Thus, critical decisions have to be made regarding a variety of opportunities, options and technologies. The main objective of this thesis is to develop a tool to obtain preliminary design configurations and operation patterns for district cooling energy systems by performing roughly detailed optimizations and further, to introduce a decision-making approach to help decision makers in evaluating the economic aspects and environmental performance of urban cooling systems at an early design stage. Different aspects of the subject have been investigated in the literature by several researchers. A brief survey of the state of the art was carried out and revealed that mathematical programming models were the most common and successful technique for configuring and designing cooling systems for urban areas. As an outcome of the survey, multi objective optimization models were decided to be utilized to support the decision-making process. Hence, a multi objective optimization model has been developed to address the complicated issue of decision-making when designing a cooling system for an urban area or district. The model aims to optimize several elements of a cooling system such as: cooling network, cooling technologies, capacity and location of system equipment. In addition, various energy resources have been taken into consideration as well as different solar technologies such as: trough solar concentrators, vacuum solar collectors and PV panels. The model was developed based on the mixed integer linear programming method (MILP) and implemented using GAMS language. Two case studies were investigated using the developed model. The first case study consists of seven buildings representing a residential district while the second case study was a university campus district dominated by non-residential buildings. The study was carried out for several groups of scenarios investigating certain design parameters and operation conditions such as: Available area, production plant location, cold storage location constraints, piping prices, investment cost, constant and variable electricity tariffs, solar energy integration policy, waste heat availability, load shifting strategies, and the effect of outdoor temperature in hot regions on the district cooling system performance. The investigation consisted of three stages, with total annual cost and CO2 emissions being the first and second single objective optimization stages. The third stage was a multi objective optimization combining the earlier two single objectives. Later on, non-dominated solutions, i.e. Pareto solutions, were generated by obtaining several multi objective optimization scenarios based on the decision-makers’ preferences. Eventually, a decision-making approach was developed to help decision-makers in selecting a specific solution that best fits the designers’ or decision makers’ desires, based on the difference between the Utopia and Nadir values, i.e. total annual cost and CO2 emissions obtained at the single optimization stages. / Die Energieverbrauchsraten haben in den letzten Jahrzehnten auf globaler Ebene dramatisch zugenommen. Diese Erhöhung ist zu einem großen Teil in den jüngst hohen Temperaturniveaus, vor allem in der Sommerzeit, begründet, die einen starken Anstieg der Nachfrage nach Klimaanlagen verursachen. Solche Ereignisse sind deutlich in Entwicklungsländern zu beobachten, vor allem in heißen Klimaregionen, wo Menschen vor allem konventionelle Klimaanlagensysteme benutzen. Diese Systeme verfügen meist über eine ineffiziente Leistungsfähigkeit und wirken sich somit negativ auf die Umwelt aus, was wiederum zur globalen Erwärmung beiträgt. In den letzten Jahren ist die Nachfrage nach Stadt- oder Fernkältetechnologien und -Netzwerken als Alternative zu konventionellen Systemen aufgrund ihrer höheren Effizienz und besseren ökologischen Verträglichkeit satrk gestiegen. Ein effizientes Design für Fernkühlsysteme zu erhalten, ist allerdings eine komplexe Aufgabe, die die Integration einer breite Palette von Kühltechnologien, verschiedener Konfigurationsmöglichkeiten von Netzwerk-Layouts und unterschiedlicher Energiequellen erfordert. Hierfür ist das Treffen kritischer Entscheidungen hinsichtlich einer Vielzahl von Möglichkeiten, Optionen und Technologien unabdingbar. Das Hauptziel dieser Arbeit ist es, ein Werkzeug zu entwickeln, das vorläufige Design-Konfigurationen und Betriebsmuster für Fernkälteenergiesysteme liefert, indem aureichend detaillierte Optimierungen durchgeführt werden. Zudem soll auch ein Ansatz zur Entscheidungsfindung vorgestellt werden, der Entscheidungsträger in einem frühen Planungsstadium bei der Bewertung städtischer Kühlungssysteme hinsichtlich der wirtschaftlichen Aspekte und Umweltleistung unterstützen soll. Unterschiedliche Aspekte dieser Problemstellung wurden in der Literatur von verschiedenen Forschern untersucht. Eine kurze Analyse des derzeitigen Stands der Technik ergab, dass mathematische Programmiermodelle die am weitesten verbreitete und erfolgreichste Methode für die Konfiguration und Gestaltung von Kühlsystemen für städtische Gebiete sind. Ein weiteres Ergebnis der Analyse war die Festlegung von Mehrzieloptimierungs-Modelles für die Unterstützung des Entscheidungsprozesses. Darauf basierend wurde im Rahmen der vorliegenden Arbeit ein Mehrzieloptimierungs-Modell für die Lösung des komplexen Entscheidungsfindungsprozesses bei der Gestaltung eines Kühlsystems für ein Stadtgebiet oder einen Bezirk entwickelt. Das Modell zielt darauf ab, mehrere Elemente des Kühlsystems zu optimieren, wie beispielsweise Kühlnetzwerke, Kühltechnologien sowie Kapazität und Lage der Systemtechnik. Zusätzlich werden verschiedene Energiequellen, auch solare wie Solarkonzentratoren, Vakuum-Solarkollektoren und PV-Module, berücksichtigt. Das Modell wurde auf Basis der gemischt-ganzzahlig linearen Optimierung (MILP) entwickelt und in GAMS Sprache implementiert. Zwei Fallstudien wurden mit dem entwickelten Modell untersucht. Die erste Fallstudie besteht aus sieben Gebäuden, die ein Wohnviertel darstellen, während die zweite Fallstudie einen Universitätscampus dominiert von Nichtwohngebäuden repräsentiert. Die Untersuchung wurde für mehrere Gruppen von Szenarien durchgeführt, wobei bestimmte Designparameter und Betriebsbedingungen überprüft werden, wie zum Beispiel die zur Verfügung stehende Fläche, Lage der Kühlanlage, örtliche Restriktionen der Kältespeicherung, Rohrpreise, Investitionskosten, konstante und variable Stromtarife, Strategie zur Einbindung der Solarenergie, Verfügbarkeit von Abwärme, Strategien der Lastenverschiebung, und die Wirkung der Außentemperatur in heißen Regionen auf die Leistung des Kühlsystems. Die Untersuchung bestand aus drei Stufen, wobei die jährlichen Gesamtkosten und die CO2-Emissionen die erste und zweite Einzelzieloptimierungsstufe darstellen. Die dritte Stufe war ein Pareto-Optimierung, die die beiden ersten Ziele kombiniert. Im Anschluss wurden nicht-dominante Lösungen, also Pareto-Lösungen, erzeugt, indem mehrere Pareto-Optimierungs-Szenarien basierend auf den Präferenzen der Entscheidungsträger abgebildet wurden. Schließlich wurde ein Ansatz zur Entscheidungsfindung entwickelt, um Entscheidungsträger bei der Auswahl einer bestimmten Lösung zu unterstützen, die am besten den Präferenzen des Planers oder des Entscheidungsträgers enstpricht, basierend auf der Differenz der Utopia und Nadir Werte, d.h. der jährlichen Gesamtkosten und CO2-Emissionen, die Ergebnis der einzelnen Optimierungsstufen sind.

[pt] O objetivo deste trabalho é contribuir para a discussão sobre a participação de atores domésticos no processo decisório de política externa brasileira, tendo em vista as possibilidades de ruptura com o padrão centralizador que tem caracterizado nossa diplomacia, a partir da liberalização política e econômica. Nosso objeto de análise é a política externa de Fernando Henrique Cardoso para a integração energética com a Bolívia, na qual procuramos identificar a participação da Petrobras nas negociações para construção do gasoduto que conecta os dois países. Concluímos que, apesar da consolidação daqueles dois fenômenos na gestão Cardoso, permanece uma tendência à centralização do poder decisório no Executivo. Enquanto as posições da Petrobras foram contrárias às das elites burocráticas que lideraram as negociações, os interesses da empresa foram barrados, levando-a a atuar dentro de sua lógica pública, ou seja, privilegiando objetivos políticos e macroeconômicos em detrimento de metas corporativas. Apenas quando suas preferências convergiram com as do Executivo - o que se deu na fase de implementação do gasoduto -, a Petrobras conseguiu acomodá-las no processo negociador, abrindo brecha para que suas estratégias de expansão fossem postas em prática. O instrumental teórico utilizado reúne abordagens de Economia política, teorias liberais de Relações Internacionais e modelos analíticos de processo decisório de política externa. / [en] The aim of this work is to contribute to the debate on domestic actors participation in the decision-making process of Brazilian foreign policy, regarding the possibilities of change in the patterns of centralization, emerged with political and economic liberalization. Our focus is Cardoso´s foreign policy for energy integration with Bolivia, in which we try to identify the role of Petrobras in negotiations for the construction of the gas pipeline which connects both countries. We conclude that, despite consolidation of those phenomena on Cardoso´s term, there is still a tendency of power decision centralization in Executive sphere. While Petrobras was contrary to bureaucratic elites´s objectives, company´s interests were precluded, leading it to act based on its public side. It meant that company´s priorities were political and macroeconomic objectives, not its corporative aims. It was only when Petrobras´s preferences converged with government ones - which happened during gas pipeline implementation - that they could be incorporated into public policy and company´s growth strategies could be put into practice. Theoretical framework consists of Political Economy approaches, International Relations liberal theories and analytical models of foreign policy decisionmaking process.

The experience of electric energy shortage in 2001 demonstrated that our dependence almost exclusively on hydroelectricity could fetch great problems to Brazil. Thus being, the existence of trustworthy alternatives of energy must exist, at the very least, as a reserve. For this reason, the perspective of decentralizing the energy production as a form of promoting the socioeconomic development of remote communities not connected to the public distribution system as well for mass production of electricity, are the motivations of this work. Such situation justified the analysis of performance and development of the integration of diverse types of alternative primary sources by transforming them into current sources as a means of preventing the circulation of current due to voltage differences across the sources. Control of the load voltage uses the modulation of a secondary load in parallel with a primary load in such a way that current excesses from the current sources are drained only through the secondary load, remaining unchanged the conditions for the primary load. To manage the voltage and current distribution in the main load, a module, dedicated and expandable controller is proposed for hybrid systems of electric energy generation such as those using wind-solar-storage for generation of electric energy in a trustworthy form, unassisted and independent. The proposed integrated system of energy does allow the control and integration of the most usual forms of energy generation such as hydraulic, wind, storage of energy, specially, in batteries. The control program is also adjusted to integrate other forms of generation, independent of its origin. The control as a whole is based on the algorithm "Hill Climbing Control" (HCC) for individual maximization of the generated power and rotation in each source and regulating the voltage across the load, in order to get the best advantage from the installations. In this dissertation is also shown some practical results about the proposed theory on a prototype of control based on the micro controller PIC18F452 for distribution of energy from a power plant of electric energy generation installed and operating in the CEEMA-UFSM campus. Furthermore, the controller module of power as presented in this work is more useful among others because it allows the use of hybrid electronics and microelectronics that are able of concentrating several circuits in a only "chip", including control functions for power conversion, A/D devices, program memory, data memory, modules for capture and comparison, timers and PWM modules. / A experiência do racionamento de energia elétrica no ano de 2001 no Brasil demonstrou que nossa dependência quase que exclusivamente da hidroeletricidade pode nos trazer grandes problemas. Assim sendo, a existência de alternativas de energia confiáveis deve existir, no mínimo, como reserva. Por esse motivo, a perspectiva da descentralização da produção de energia como forma de promoção do desenvolvimento sócio-econômico de comunidades não atendidas pelas formas convencionais de energia bem como para produção em massa de energias alternativas para grandes sistemas de potência, foram as motivações deste trabalho. A necessidade de um conhecimento melhor da integração entre as fontes de energia. Tais temas justificaram a realização da análise do desempenho e o desenvolvimento de tecnologia para a integração de diversos tipos de fontes alternativas transformadas em fontes de corrente como forma de se evitar a circulação de correntes entre as fontes por diferenças individuais de tensão. O controle da tensão de carga usa a modulação de uma carga secundária em paralelo com outra primária tal que os excessos de corrente das fontes sejam drenados apenas para a carga secundária mantendo-se inalteradas as condições da carga primária. Para gerenciar a distribuição das correntes e a tensão na carga principal, utilizou-se um controlador modular, dedicado e expansível para sistemas híbridos de geração de energia elétrica tais como o eólico-solararmazenamento para geração de energia elétrica de forma confiável, desassistida e autônoma. O sistema de energia desenvolvido permite o controle e o acionamento integrados das formas mais conhecidas de geração de energia envolvendo fontes como a hidráulica, a eólica, armazenadores de energia, em especial, as baterias. O programa de controle é adequado para integrar outras formas de geração, independente de sua origem. O controle como um todo, baseia-se no algoritmo "Hill Climbing Control" (HCC) para maximização individual da potência gerada em cada fonte e para o contingenciamento da rotação pela carga, de modo a se obter o melhor proveito das instalações. Por outro lado, a tensão de saída é modulada através da carga secundária de tal forma a compor uma impedância a ser vista pela fonte de corrente resultante das fontes primárias que estabilize em torno da tensão nominal. Esta dissertação mostra os resultados práticos relativos a um protótipo de controle baseado no PIC18F452 para distribuição de energia a partir de uma central de geração de energia elétrica instalado e funcionando no campus da UFSM. O módulo controlador de potência como se apresenta, presta-se para a utilização dos recursos da eletrônica híbrida e da microeletrônica que podem concentrar num único "chip" diversos circuitos, incluindo conversores de potência, conversores A/D, memória de programa, memória de dados, módulos de captura e comparação, temporizadores e módulos PWM, entre outros.

La pompe à chaleur industrielle très haute température (PAC THT) à compression mécanique de vapeur, fonctionnant à l'électricité, figure parmi l'une des technologies innovantes les plus efficaces permettant de valoriser les rejets thermiques industriels à basse et moyenne température (<90 °C). Néanmoins, compte tenu des besoins industriels actuels de chaleur, les niveaux de température cible atteignable par les PACs restent trop faibles et freinent fortement son implantation. Les procédés de séchage, dans leur grande majorité, rejettent des buées ou de la vapeur d'eau à moyenne température (50 °C-90 °C) et ont des besoins de chaleur à très haute température (110 °C-150 °C). Le grand écart de température entre la source et le besoin de chaleur ainsi que le niveau de température du besoin, font qu'aujourd'hui envisager l'intégration d'une PAC dans ce type de procédés relève d'un défi énergétique et technologique particulièrement intéressant, dont l'enjeu économique est considérable. Les présents travaux de recherche envisagent à l'aide d'une méthodologie générique d'optimisation de cycles thermodynamiques basée sur la minimisation de la production d'entropie dans les échangeurs de chaleur de déceler les architectures de PACs les plus efficaces d'un point de vue énergétique. L'analyse théorique a permis de déceler la haute efficacité énergétique des architectures transcritiques de PACs dans des conditions de grands glissements de température entre l'entrée et la sortie du besoin de chaleur. Le développement d'un démonstrateur de PAC transcritique très haute température fonctionnant au R32 (PAC T-THT R32) a permis d'une part de démontrer la faisabilité technique d'une PAC, pouvant atteindre la température cible de 120 °C en partant de 60 °C avec une source de chaleur disponible à 50 °C, et d'autres part de démontrer sa haute efficacité énergétique (COP = 4). / The mechanical vapour compression high temperature heat pump for industry using electricity is one of the most effective innovative technologies to recover the industrial waste heat at low and medium temperature (<90°C). However, given the current industrial heat needs, the heat pump target temperature levels remain too low and slow strongly its implantation. Overwhelmingly, the drying processes reject saturated moist air at middle temperature (50°C-90°C) and have heat needs at very high temperature (110°C-150°C). The large temperature difference between the source and the heat need and the level off temperature that is needed, today, makes the heat pump integration in such processes an interesting energy and technological challenge, whose economic stake is considerable. The present works tackle, with a generic methodology of thermodynamic optimisation cycles based on the entropy minimization in the heat exchangers, to identify the most efficiency heat pump architectures from an energy point of view. The theoretical analysis allowed to detect the transcritical heat pump architecture, in conditions of high temperature glides between the inlet and the outlet of the heat need. The development of a transcritical high temperature heat pump demonstrator using the R32 as working fluid allowed to demonstrate the technical feasibility of a heat pump that can reach the target temperature of 120°C from 60°C with an available heat source at 50°C, and to demonstrate its high energy efficiency (COP = 4).

The thesis focuses on theoretical and empirical analysis of oil and natural gas flows in Eurasia and maps Ukraine's transit position in the regional oil and gas supply chain. The aim of the thesis is to objectively evaluate possibilities of Eurasian energy integration by enlargement of the European energy market further to the East and to prospect Ukraine's involvement into a new geopolitical energy alliance, driven by EU. This dissertation builds up on economical, geographical, historical and political premises of markets integration as well as system approach of energy alliances development. It argues that (i) energy integration on contrary to traditional economic stream can be explained by system approach and geopolitical stream of energy expansionism; (ii) EU infrustructural oil and gas projects imply deeper integration of EU member-states with involed non-members and (iii) Ukraine's oil and gas transit status within Eurasian region facilitates its growing involvement into EU energy intiatives guided by the European rules. The thesis is organized into three chapters. The first one is predominately theoretical and seeks to summarize current theoretical approaches towards integration and trends of energy markets in Eurasia. The second chapter introduces the role of oil and gas transport capacities and Ukraine's transit status in resolving disparities of Eurasian energy supply chain. The third chapter describes condition of Ukrainian oil and gas infrastructure and tackles issues for reformation of national oil and gas transit pipelines. Securing access to energy supplies has been a driving factor of global development since the industrial revolution. Increasing demand for oil and gas has undermined energy and economic security of world centers. In Eurasia Europe and Asia has been competing for fossil fuels originating from Russia, Middle East and Central Asia. Since recently Eurasian energy security problem is being solved by development of new supply routes. These infrastructural projects are initiated by oil and gas consumers, suppliers and transitors competing over control in the infrastructure. Such competition destabilises Eurasian relations, leads to energy "wars", political conflicts and increases supplies disruption risks. To secure stability of energy supply chain producers, transitors and consumers of oil and gas resources should integrate, closely cooperate and jointly invest into improving the existing supply routes and efficiency of fuels consumtion, production and transportation. Oil and gas should be traded for technologies and capital securing control in the infrustucture of mutual interests. Development of further bilateral and multilateral tools of joint interest would also help in resolving energy related contradictions of the participating parties. The leading role in driving energy integration in Eurasia belongs to the EU being the most mature and advanced integration grouping in Eurasia. EU realises TEN-e projects and from recently a common foreign energy policy aimed to strengthen external cooperation with oil and gas suppliers and transitors, including Ukraine. Since 1970s Ukraine has been an important oil and gas transitor for Russian and Central Asian oil and gas to Europe. Ukrainian pipelines intermediate 10 % of oil and 50 % of gas imports of Europe. To counterbalance Russian energy diplomacy over Ukraine, EU is supporting Ukraine's efforts in such energy alliances as INOGATE or GUAM. Ukraine's recent accession to the South Eastern-European Energy Community should improve stability of gas and oil supplies to Europe and facilitate reformation of national transit capacities.