Tesis: "Energia, Fuel cell"

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Furlan, André Luís. "Análise técnica e econômica do uso do hidrogênio como meio armazenador de energia elétrica proveniente de fontes eólicas." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263953.

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Orientadores: Ennio Peres da Silva, Newton Pimenta Neves Junior Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica Made available in DSpace on 2018-08-20T12:25:52Z (GMT). No. of bitstreams: 1 Furlan_AndreLuis_D.pdf: 2850462 bytes, checksum: cf9586ce36bd523119ff4727d43989f7 (MD5) Previous issue date: 2012 Resumo: Este trabalho faz uma análise técnico-econômica do uso do hidrogênio como meio armazenador de energia elétrica proveniente de fonte eólica, cuja natureza imprevisível do vento não pode garantir sua quantidade de energia elétrica ofertada. Para resolver este problema, foram propostos dois sistemas de armazenamento operando de modos diferentes, para os quais foi desenvolvido um modelo matemático para o dimensionamento deles, implementado numa planilha eletrônica, no qual foram consideradas as principais características e eficiências dos equipamentos que compõem os sistemas, bem como a garantia física característica da usina eólica. A seguir, foi realizada uma análise econômica dos sistemas tendo sido verificado que o custo de produção da energia elétrica a partir do primeiro modo de operação proposto foi aproximadamente 47,5% maior que o custo de produção de energia da usina eólica sem armazenamento (130 R$/MWh) e, considerando o segundo modo, a diferença foi 92% maior. No caso da energia elétrica gerada pela célula a combustível o valor obtido foi de 1.180,00 R$/MWh e 1.250,00 R$/MWh considerando, respectivamente, o primeiro e segundo modo de operação Abstract: The current work aims to present a technical-economical analysis of the use of hydrogen as a means to store energy generated by wind power systems, since the wind regime is unpredictable and thus there is no guarantee for the amount of power offered. First of all, two storage systems were proposed and a mathematical model was established considering the main features and efficiencies of the equipment that compose the systems as well as the wind power energy guarantee. Secondly, an economic analysis of those systems was carried out. The cost of power generation for the first mode of operation was approximately 47,5% larger than that of a similar wind power system without storage (130 R$/MWh) and, concerning the second mode, the power cost was 92% larger. Regarding the energy generated by the fuel cell only, the power cost was respectively 1.180,00 R$/MWh and 1.250,00 R$/MWh for each of the operation modes Doutorado Engenharia Mecanica Doutor em Planejamento de Sistemas Energéticos

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Gonzatti, Frank. "Bases experimentais para o projeto, automação e instalação de sistemas de geração de energia com células de combustível." Universidade Federal de Santa Maria, 2005. http://repositorio.ufsm.br/handle/1/8440.

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The main concern of this dissertation is the establishment of experimental bases for the project, automation, and installation of a micro-power plant for electric power generation based on PEM fuel cell stacks (BCS Technology). The plant operates automatically, and its control is accomplished by a microcontroller acting directly in the temperature, in the humidity of the membrane, in the amount of reaction air, in the monitoring of the individual voltage of each cell and in the attempt of recovery of a possibly problematic cell. For control operation special auxiliary mechanisms are necessary to avoid dangerous conditions to the stack. The making of the prototype is of low cost and easily found items in national market access have been intended. Special controlled atmospheres were also designed and built to shelter the stack and obtain safety operation when the stack is on. Therefore, the work tries to find the theoretical and experimental bases for a static power plant implementation based on fuel cell systems. O tema principal desta dissertação é o estabelecimento de bases experimentais para o projeto, automação e a instalação de uma microcentral de geração de energia elétrica com pilhas de células de combustível do tipo PEM (BCS Technology). Esta central deve operar automaticamente, comandada por microcontrolador que atua diretamente na temperatura, na umidade da membrana, na quantidade de ar de reação, no monitoramento da tensão individual de cada célula e na tentativa da recuperação de células problemáticas. Para que este controle atue são necessários mecanismos auxiliares especiais de forma a não causarem danos às células. Na confecção do protótipo procurou-se especificar dispositivos de baixo custo e de fácil disponibilidade no mercado nacional. Locais especiais também foram projetados e construídos para abrigar a pilha quando em operação de forma a garantir o máximo de segurança. Portanto, este trabalho busca fornecer bases teóricas e experimentais para a implementação de uma central estacionária de geração com pilhas de células de combustível.

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Ramsdorf, Marcelo de Almeida [UNESP]. "Células-combustível a etanol direto embarcadas em aeronaves: estudo de utilização e recuperação de calor residual." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/137847.

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Submitted by MARCELO RAMSDORF (marceloramsdorf@gmail.com) on 2016-04-07T18:09:06Z No. of bitstreams: 1 Dissertacao_Marcelo_Ramsdorf.pdf: 3773711 bytes, checksum: 2740d7feeceb5938048e38e5ea25595e (MD5) Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-04-08T11:53:43Z (GMT) No. of bitstreams: 1 ramsdorf_ma_me_guara.pdf: 3773711 bytes, checksum: 2740d7feeceb5938048e38e5ea25595e (MD5) Made available in DSpace on 2016-04-08T11:53:43Z (GMT). No. of bitstreams: 1 ramsdorf_ma_me_guara.pdf: 3773711 bytes, checksum: 2740d7feeceb5938048e38e5ea25595e (MD5) Previous issue date: 2016-02-26 Não recebi financiamento O uso de células combustível de baixa temperatura embarcadas em aeronaves pode favorecer a geração de energia elétrica sem maiores impactos ambientais. Se, por um lado, o projeto de aeronaves atuais requer o uso de sistemas dedicados, por outro há uma maior demanda de energia elétrica a bordo. Isto significa que a pressurização da cabine, o sistema anti-gelo e a hidráulica da aeronave não devem depender da extração de ar do compressor das turbinas ou da potência de eixo. Entretanto, células combustível a hidrogênio apresentam dificuldades aos projetistas devido aos tanques de armazenamento, componentes em alta pressão e altas temperaturas para a reforma. Neste contexto, as células-combustível a etanol direto são uma tecnologia promissora. Publicações recentes mostram que, devido à baixa eficiência, células a etanol líquido em eletrólitos de membrana polimérica produzem calor residual. Conforme o Diagrama de Sankey obtido neste trabalho, 68% da energia total do combustível é convertida em calor, que deve ser gerenciado para evitar o ressecamento da membrana e o colapso do sistema. No presente trabalho um arranjo teórico de células a etanol direto é estudado. A metodologia leva em conta as demandas de energia de uma aeronave a jato de transporte regional em cada etapa do voo (táxi, decolagem, cruzeiro, descida e pouso). O trabalho apresenta uma contribuição inédita pela análise exergética do arranjo, que fornece um bom critério para a melhor escolha entre um sistema de cogeração ou recuperação de calor a bordo. Em um sistema otimizado, o calor residual pode ser utilizado no aquecimento de cabine ou aquecimento do combustível da aeronave. São apresentadas algumas estimativas de capacidade de aquecimento do combustível e da produção de água aquecida. A metodologia pode auxiliar o projetista a escolher entre duas configurações possíveis (com recuperação de calor no aquecimento de cabine ou puramente elétrico) dependendo da missão proposta para a aeronave. The use of low temperature fuel cell stacks onboard aircrafts may provide a good way to generate electricity with less environment impact. Nowadays, the design of jet aircrafts requires embedded systems, which demand more electric power. This means that cabin air pressure, anti-icing and hydraulics should not depend on the engine bleed air or shaft power. However, hydrogen fuel cells pose difficulties for aircraft designers due to the storage tanks, high pressure systems and high temperatures for reforming. In this context, direct ethanol polimeric fuel cells are a promising technology. Recent publications show that the low efficiency of liquid ethanol in polymeric electrolyte produces waste heat. According to the Sankey Diagram obtained, 68% of the total input energy is heat that must be managed to avoid electrolyte drying and system collapse. In this article, a theoretical direct ethanol fuel cell stack is studied. The methodology takes into account the energy demands of a regional jet for each flight regime (start up, taxi, take off, cruise, descend and landing). It provides an unprecedented exergetic analysis that points out a good hint to choose between cogeneration or heat recovery onboard aircraft. The waste heat may be recovered for cabin and aircraft fuel heating in an optimized system. Some predictions for aircraft fuel heating capacity and water production are also presented. The methodology may help designers to decide which configuration is more appropriate (whether use heat recovery for cabin heating or a pure electric fuel cell stack) for the aircraft mission sought.

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Gonzatti, Frank. "Fundamentos para concepção, controle e automação de uma planta armazenadora de energia utilizando hidrogênio." Universidade Federal de Santa Maria, 2017. http://repositorio.ufsm.br/handle/1/12933.

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Electrical generation with renewable sources is intermittent due to the characteristics of the primary energy (sun, wind, run of water, etc.). This feature can cause fluctuations and distortions on the voltage levels compromising power quality, stability and reliability when connected to an electrical system. The storage of energy acting together either as standalone unit or interconnected to the generating source of the public network can increase the penetration of these sources in the energy matrix. Among the different forms of energy storage, the one using hydrogen is quite promising because of its characteristics such as low environmental impact, high energy density, and energy high storage capacity. In this thesis, it is proposed some basis for designing, controlling and analyzing a hydrogen-based energy storage plant, consisting of a set of an alkaline type electrolyzer, hydrogen storage in the form of metallic hydrides and a fuel cell stack of the type PEM. The proposed plant was modeled and validated through experimental tests. The model allowed simulation of the main physicochemical quantities involved in the process of generation, storage and conversion of hydrogen into electricity storage. The fuel cell stack that is part of the energy storage was automated to avoid damages to the membrane, acting mainly on temperature control, elimination of contaminants on the anode side, and voltage reestablishment through the controlled application of short-circuits. The metal hydride cylinder storing hydrogen has been also automated with the main purpose of performing a thermal exchange in the best possible way between the metal alloy and the environment. Reuniting these devices to make them to act in synchrony, the plant was automated, controlled and monitored through a software developed in the LabView platform, making it more autonomous the whole plant. This program allows also acquisition and storage of the main physico-chemical quantities during the plant operation. These magnitudes collected in the tests along with the simulation results were analyzed and characterized the fundaments of this thesis. A geração de energia elétrica a partir de fontes renováveis é intermitente devido às características da energia primária (sol, vento, fio d'água, etc.) e podem causar oscilações e distorções nos níveis de tensão comprometendo a qualidade da energia, a estabilidade e a confiabilidade quando conectadas ao sistema elétrico. O armazenamento de energia atuando junto a fonte geradora isolada ou interligada à rede pública pode aumentar a penetração dessas fontes, de baixo impacto ambiental, na matriz energética. Entre as diferentes formas de armazenamento de energia, o uso de hidrogênio é considerado bastante promissor devido ao baixo impacto ambiental, alta densidade de energia e alta capacidade de armazenamento. Nessa tese, propõe-se as bases para concepção, controle e análise de uma planta armazenadora de energia baseada em hidrogênio, constituída por um eletrolisador do tipo alcalino, armazenamento de hidrogênio na forma de hidretos metálicos e uma pilha de células a combustível do tipo PEM. A planta proposta foi modelada e validada através de testes experimentais. O modelo permite simular as principais grandezas físico-químicas envolvidas desde o processo de geração, armazenamento e conversão do hidrogênio armazenado em eletricidade. A pilha de células a combustível, que faz parte do armazenador de energia, foi automatizada para operar sem danos a membrana, atuando principalmente no controle da temperatura, na eliminação de contaminantes no lado do ânodo e no reestabelecimento da tensão através da aplicação controlada de curtos-circuitos na pilha. O cilindro de hidreto metálico que armazena o hidrogênio também foi automatizado com o intuito principal de realizar a troca térmica da melhor forma possível entre a liga metálica e o ambiente. Unindo esses dispositivos para atuarem em sincronia, a planta foi automatizada, controlada e monitorada através de um software desenvolvido na plataforma LabView, de tal forma a torná-la mais autônoma. Este programa também permite que sejam adquiridos e armazenados o comportamento das principais grandezas físico-químicas durante operação da planta. Essas grandezas levantadas em testes juntamente com resultados de simulações, foram analisadas e caraterizada os fundamentos desta tese.

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Lopes, Daniel Gabriel. "Analise tecnica e economica da inserção da tecnologia de produção de hidrogenio a partir da reforma de etanol para geração de energia eletrica com celulas a combustivel." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263838.

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Orientador: Ennio Peres da Silva Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica Made available in DSpace on 2018-08-12T18:33:39Z (GMT). No. of bitstreams: 1 Lopes_DanielGabriel_D.pdf: 1342429 bytes, checksum: 07781c234da4ed70010b3d55a91f6986 (MD5) Previous issue date: 2009 Resumo: Este trabalho apresenta uma análise técnica e econômica da utilização do processo de reforma de etanol para produção de hidrogênio e da utilização deste hidrogênio para produção de energia elétrica em uma célula a combustível do tipo PEMFC de 5,0 kW. A análise técnica se fundamenta em dados experimentais, inéditos, obtidos do protótipo de um reformador de etanol desenvolvido a partir de uma parceria entre o Laboratório de Hidrogênio da UNICAMP e a empresa Hytron, levando-se em consideração as principais características do funcionamento real do que representa o estado da arte desta tecnologia no Brasil. A metodologia utilizada para realização da análise econômica foi desenvolvida para se determinar os valores de referência relativos ao custo do hidrogênio produzido (30,34 R$/kg) e da energia elétrica gerada (2,30 R$/kWh) e indicar metas para a inserção futura destas tecnologias. Os resultados obtidos permitiram que se concluísse que os atuais custos de geração do hidrogênio produzido pelo protótipo do reformador de etanol são economicamente competitivos, assim como o custo de geração da energia elétrica com utilização deste hidrogênio na célula a combustível quando comparado com a aplicação de outras tecnologias alternativas, mas não com os preços da eletricidade da rede de distribuição do Sistema Interligado brasileiro. Abstract: This work presents a technical and economical analysis of the use of the technology of hydrogen production by the process of autothermal reforming of ethanol and the use of the hydrogen for the production of electric energy in a 5 kW PEMFC. The technical analysis is founded in unpublished experimental data obtained from the prototype of a ethanol reformer developed by the Hydrogen Laboratory at UNICAMP and by Hytron, taking into account the main characteristics of its real functioning which represents the state of the art of this technology developed in Brazil. The methodology applied for the economical analysis was developed in order to determine the reference values concerning the cost (30,34 R$/kg) of the hydrogen produced and the electric energy generated (2,30 R$/kWh), and to indicate the milestones for the future introduction of these technologies. The results led to the conclusion that the present costs of hydrogen production by the prototype of the ethanol reformer are lower than the present prices practiced in the market, and that the cost of the electric energy generation with the hydrogen in a PEMFC is lower than those obtained by the use of other alternative technologies, except when compared to grid-connected power system in Brazil. Doutorado Doutor em Planejamento de Sistemas Energéticos

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Aguiar, Cassius Rossi de. "Contribuição ao gerenciamento e controle de células a combustível e armazenadores de energia para a operação em geração distribuída." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18153/tde-09112017-103011/.

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A presente tese busca desenvolver uma metodologia para o gerenciamento e controle de uma geração distribuída que utiliza como fonte principal células a combustível do tipo PEM (Proton Exchange Membrane). A finalidade do trabalho consiste em analisar, controlar e gerenciar a operação da célula a combustível (CaC) nas operações ilhada e conectada em relação à rede de distribuição. Nos primeiros capítulos do texto é elaborada uma revisão acerca do princípio de funcionamento e do modelo da CaC. Após este estágio inicial, são analisadas e modeladas as estruturas dos estágios CC e CA que compõem a geração distribuída. Para o modo conectado é desenvolvida uma estratégia para o controle da tensão do link CC que, a partir da regulação da corrente do estágio CA, permite o gerenciamento da potência fornecida pela CaC. Sequencialmente ao texto e com a adição do estágio de armazenamento de energia, é apresentada uma proposta que vincula a dinâmica da CaC com a estrutura de gerenciamento do estágio CC e CA. Esse fato garante que a alteração do ponto de operação da CaC seja descrito conforme uma dinâmica predeterminada, garantindo assim que transitórios não sejam absorvidos pela CaC. Como parte final da tese, é desenvolvida uma estratégia para a inicialização da CaC, a qual associa o próprio comportamento da célula e o estágio de armazenamento de energia. Os resultados apresentados ao longo do texto mostram que as estruturas propostas tornam a CaC menos sensível a transitórios de carga, além de serem capazes de deslocar (gerenciar) o ponto de operação da célula. Ao final de cada capítulo, são apresentados resultados experimentais e de simulações que auxiliam o entendimento e suportam as propostas do trabalho. This thesis proposes a methodology for management and control of distributed generation with a Proton Exchange Membrane Fuel Cell (PEMFC) as the main source. Additionally, the analysis of performance is used when the PEM fuel cell operates in two different operation modes, i.e. in grid-connected and stand-alone modes. In the first chapters, a review of main features and a mathematical model of fuel cells are presented. Sequentially, the theoretical models of the DC- and AC-power converters are analyzed. For grid-connected operation mode, a strategy based on the DC-link voltage control is proposed via current regulation of the AC stage affording thus the management of the power produced by the fuel cell. Additionally, with the use of the storage devices, a proposal that associates the dynamics of the PEM fuel cell with the DC and AC stages is shown. This fact ensures that the movement of the fuel cell operating point is described within a predetermined dynamic, ensuring that transients are not absorbed by the fuel cell. Finally, a strategy for the startup of fuel cell in association with the energy storage stage is developed. The results show that the proposed structures makes the cell less sensitive to the load transient, in order to move (manage) the fuel cell operating point. At the end of each chapter, experimental and simulation results are presented to support the proposed approach.

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CAVALCANTI, Davi de Lima. "Potencial biotecnológico de chlorella vulgaris: aplicação em biocelulas a combustível fotossintética, produção de energia e sequestro de co2." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/18531.

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Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2017-04-10T17:20:12Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO -DAVI CAVALCANTI certa.pdf: 1682949 bytes, checksum: e88ff7ec323c0df6eb4f0102509ba5b3 (MD5) Made available in DSpace on 2017-04-10T17:20:12Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO -DAVI CAVALCANTI certa.pdf: 1682949 bytes, checksum: e88ff7ec323c0df6eb4f0102509ba5b3 (MD5) Previous issue date: 2016-02-23 Capes O crescimento da população mundial vem causando um aumento substancial na demanda por energia o que poderá causar em curto prazo uma crise energética, pois grande parte da energia consumida em todo mundo é proveniente de fontes não renováveis como o petróleo, já que sua prospecção e utilização tem causado grandes danos a natureza, impactando vários ecossistemas e colaborando com o aquecimento global. Por estes motivos, novas tecnologias para geração de energia limpa vêm sendo criadas. Um exemplo destas são as células a combustível, que são dispositivos que convertem energia química em elétrica. Porém esta tecnologia apresenta algumas limitações, como deficiências na transferência de elétrons, baixa geração de potência e altos custos associados a utilização de catalizadores metálicos, os quais aumentam os custos de implantação e dificultam sua utilização em larga escala. Visando superar estas limitações uma variação desta tecnologia foi desenvolvida, a chamada célula a combustível fotossintética. Neste tipo de célula a combustível, microalgas como a Chlorella vulgaris são utilizadas no compartimento catódico substituindo catalizadores químicos melhorando sua sustentabilidade e reduzindo os custos de implantação. As utilizações de cátodos de microalgas também colaboram com o sequestro de carbono da atmosfera, o convertendo em oxigênio e biomassa rica em metabolitos de grande valor comercial como amido e lipídios. No presente estudo a microalga C. vulgaris foi utilizada no compartimento catódico de uma célula a combustível fotossintética a fim de se analisar sua eficiência na produção de energia, sua capacidade de sequestrar o dióxido de carbono da atmosfera e seu acúmulo de materiais de reserva como amido e lipídios totais. Na primeira parte deste estudo a microalga C. vulgaris foi utilizada como aceptora de elétrons em um compartimento catódico, onde durante 10 dias de experimento foram avaliados a quantidade de CO2 capturada pelas células de algas (7mg/L de CO2), a composição da biomassa, Amido (3%) e Lipídios (70%) e parâmetros eletroquímicos como a Eficiência Coulômbica (CE = 33,1%) e densidade de corrente máxima (Idmax = 147 mA cm²). Em seguida esta condição foi submetida a um planejamento fatorial completo 2², onde as variáveis independentes, tempo de iluminação e a concentração de nitrogênio foram testadas sobre a produção de eletricidade e acúmulo de amido e lipídios. Durante os experimentos foi constatado que a iluminação é o fator que mais influi na geração de energia, onde foram obtidos valores de densidade de corrente máxima Idmax = 178 mA/cm² com uma eficiência coulômbica de 42,5%, além de uma acumulação máxima de amido de 38% e 77% de lipídios, demonstrando que a utilização de um cátodo fotossintético para produção de energia é viável e eficiente na produção de metabólitos com elevado valor comercial. The global population growth has caused a substantial increase in demand for energy, which in short-term may cause an energy crisis, since much of the energy consumed throughout the world comes from non-renewable sources like oil. Besides its exploration and use cause great damage to the environment, affecting diverse ecosystems and contributing to global warming. For those reasons, are being created new technologies for clean energy generation. An example of these technologies is Fuel Cells, which are devices that convert chemical energy into electric. However, this technology has some limitations, such as defects in electron transfer, low power output and high costs associated with the use of metal catalysts, which increase deployment costs and hamper its use on a large scale. Aiming to overcome these limitations, a variation of this technology was developed, the so-called photosynthetic fuel cell. In this type of fuel cell, microalgae such as Chlorella vulgaris are used in the cathode compartment replacing chemical catalysts improving their sustainability and reducing deployment costs. The uses of microalgae cathodes also collaborate with carbon capture from the atmosphere, turning it into oxygen and biomass rich in metabolites of great commercial value as starch and lipids. In the current study the microalgae C. vulgaris was used in the cathode compartment of a photosynthetic fuel cell in order to analyze its energy production efficiency, their ability to sequester atmospheric carbon dioxide and its accumulation of reserve materials such as starch and total lipids. The first part of this study microalga C. vulgaris was utilized as an electron acceptor in a cathode compartment, which were analyzed during 10 days of experiment the amount of CO2 captured by the algae cells (7mg/L-1 of CO2), the composition of the biomass starch (3%) and lipids (70%) and electrochemical parameter as coulombic efficiency (CE = 33.1%) and the maximum current density (mA Idmax = 147 cm²). Then this condition was subjected to a complete factorial design 2² where the independent variables, illumination time and the concentration of nitrogen were tested on the production of electricity and accumulation of starch and lipids. During the experiments it was evidenced that enlightenment is the factor that most affects the power generation, which were obtained maximum current density values Idmax = 178 mA/cm² with a coulombic efficiency of 42.5%, and a maximum accumulation of 38% of starch and 77% of lipid, demonstrating that the use of a photosynthetic cathode for energy generation is feasible, and also in the production of metabolites with a high commercial value.

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Micena, Raul Pereira. "Estação de produção e abastecimento de hidrogênio solar : análise técnica e econômica /." Guaratinguetá, 2020. http://hdl.handle.net/11449/192426.

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Orientador: José Luz Silveira Resumo: A utilização do hidrogênio como insumo energético para aplicações de transporte depende da disponibilização de alternativas renováveis para sua produção. Uma delas são as estações com eletrólise alimentada por uma planta solar fotovoltaica on-grid. Nesse trabalho, assume-se a substituição da atual frota de táxis da cidade brasileira Guaratinguetá-SP por veículos a célula-a-combustível. Para atender a demanda de hidrogênio dos veículos, é preciso produzir 170,24 kg de hidrogênio por dia. Esse hidrogênio deve ser fornecido comprimido a uma pressão de 87,5 MPa e a uma temperatura de -40°C, de acordo com norma vigente. Assim, propõe-se uma análise energética com o cálculo da energia necessária para produzir o gás por meio de uma planta fotovoltaica on-grid, bem como as perdas envolvidas. Também são calculadas energias e perdas relacionadas com a compressão e refrigeração do hidrogênio, bem como o volume dos tanques. Os resultados indicam uma necessidade de geração de 10.037 kWh por dia para atender todos os processos envolvidos na estação de abastecimento. Desse total, 56,53 % é entregue na forma de hidrogênio. Se for considerada a energia solar que incide diretamente sobre os painéis, esse percentual é de 9,33 %. A maior parte das perdas se concentra na conversão da irradiação solar em energia elétrica e na eletrólise da água, sendo estas as duas principais oportunidades para melhorias de eficiência. O custo do hidrogênio foi calculado em 16,197 US$/kg se produzido com energia s... (Resumo completo, clicar acesso eletrônico abaixo) Abstract: The use of hydrogen as an energy carrier for transport applications depends on the availability of renewable alternatives for its production. One of them is the electrolysis stations powered by a grid connected photovoltaic solar plant. In this work, it is assumed that the current taxi fleet in the Brazilian city of Guaratinguetá will be replaced by fuel cell vehicles. To meet the hydrogen demand of vehicles, it is necessary to produce 170.24 kg per day. This hydrogen must be supplied compressed at a pressure of 87.5 MPa and at a temperature of -40 °C, in accordance with current regulations. Thus, an energy analysis is proposed with the calculation of the energy required to produce the gas through a photovoltaic plant connected to the grid, as well as the losses involved. Energies and losses related to hydrogen compression and cooling are also calculated, as well as the volume of the tanks. The results indicate a need to generate 10,037 kWh per day to meet all the processes involved in the supply station. Of this total, 56.53 % is delivered in the form of hydrogen. If the incoming solar in the photovoltaic panels is considered, this percentage is 9.33 %. Most of the losses are concentrated in the conversion of solar irradiation into electrical energy and in the electrolysis of water, these being the two main opportunities for efficiency improvements. The cost of hydrogen was calculated at 16,197 US$/kg if produced with photovoltaic solar energy and at 20,812 US$/kg if produce... (Complete abstract click electronic access below) Mestre

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Carnieletto, Renata. "Aproveitamento de energia vertida turbinável para produção de hudrogênio e geração distribuída." Universidade Federal de Santa Maria, 2011. http://repositorio.ufsm.br/handle/1/8486.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico In many hydroelectric power plants, while the water inflows are greater than demand, part of this water that could be used to generate energy is spilled by the dam gates and literally wasted. This dissertation discusses the use of this wasted hydroelectric potential for hydrogen (H2) generation through water electrolysis. The usage of this hydrogen can happen not only in vehicle engines or industrial applications, but in energy generation through fuel cells and behaving as an energy vector. The H2 production by electrolysis requires an energy source for its processing. This dissertation aims at to mitigate this issue by the use of the secondary energy. Besides the H2 generation aspects, it is presented the complete mathematic model of alkaline electrolyzers. With respect to the wasted hydroelectric potential approach it must be taken into account that alternative sources of energy are settled onto three bases: the energy source itself, the distribution grid and the interconnection energy source-to-grid (or source-to-load). Looking at this fact, the source connection and disconnection from the grid is a challenge for systems engineering. For this dissertation the simulation of Voltage Source Inverters (VSI) was selected to represent the islanded and grid tied conditions. For that, it is proposed an anti-islanding algorithm used to protect the system against faults that may occur in the grid. A reconnection algorithm is also included to obtain the synchronism of the alternative source with the electric grid. To control these inverters, two control techniques are presented along this text: DQ-frame and the proportional and resonant (P+Resonant) control. These control techniques are simulated to evaluate the application efficiency of such controllers. Additionally a smart control in perspectives of the smart grid was also developed and it is proposed in this dissertation. A smart grid integrated to the distribution system allows aggregation of efficient actions of all agents related to electricity services and so strategically making available the electricity goods and services. In this context, based on real-time spot pricing of the electricity obtained from the utility using an advanced metering device, the inverter control algorithm determines the optimal operating mode. This algorithm enables the inverter to: a) schedule local loads; b) determine either to local storage or selling of energy to the grid. Finally, it is shown that on-line fault detection in the system can also make possible a fast restoration of most contingence situations. Em muitas Usinas Hidrelétricas, quando as afluências de água são maiores que a demanda, uma parcela desta água que ainda poderia ser utilizada para gerar energia é desviada para o vertedouro e literalmente desperdiçada. Esta energia recebe a denominação de Energia Vertida Turbinável (EVT). Essa dissertação discute o aproveitamento da EVT para produção de hidrogênio através da eletrólise da água. O uso desse hidrogênio pode ocorrer não apenas em motores de veículos ou aplicações industriais, mas na própria geração de energia elétrica em células a combustível, agindo como vetor energético. A produção de H2 por eletrólise da água convencionalmente necessita de uma fonte de energia para o processo. Essa dissertação sugere a mitigação deste problema pela utilização de energia secundária. Além de aspectos para produção de H2, é apresentada uma modelagem matemática completa de todo este processo envolvendo os eletrolisadores alcalinos. Na abordagem da EVT há que se levar em conta que as fontes alternativas em geral estão assentadas em três fundamentos: a fonte de energia, a rede de distribuição e a interconexão fonte de energia-rede (ou fonte-carga). Com vistas a este fato, a desconexão e re-conexão entre a fonte e a rede pode ser um problema desafiador para a engenharia de sistemas. Para esta dissertação, selecionou-se a simulação dos Inversores VSI (Voltage Source Inverters) como resposta para as condições de ilhamento e conexão à rede elétrica. Para isto, propõe-se um algoritmo anti-ilhamento que visa a proteção contra as faltas que possam ocorrer na rede e um algoritmo de re-conexão à rede, incluindo o meio de sincronismo da fonte alternativa com a rede. Para controlar tais inversores, duas técnicas são apresentadas ao longo deste texto: utilizando as transformações DQ e controle proporcional e ressonante (P+Resonant). Essas duas técnicas de controle são simuladas para se avaliar a eficiência da aplicação de tais controladores. Em adicional, foi desenvolvido um controle inteligente diferenciado com perspectivas ao Smart Grid. O Smart Grid integrado aos sistemas de distribuição permite agregar de forma eficiente as ações de todos os agentes ligados a ele para que, de forma estratégica, sejam disponibilizados bens e serviços de eletricidade. Neste contexto, o controle inteligente proposto para inversores de conexão com rede a utiliza técnicas de gerenciamento pelo lado da demanda e ainda determina automaticamente o ponto ótimo de operação do inversor, possibilitando assim o planejamento e arranjo de cargas locais e a determinação de quando deve ser armazenada energia ou vendida para a rede. Mostra-se finalmente que a detecção das falhas no sistema também poderá ser praticada de forma a se poder atuar rapidamente no restabelecimento das situações de contingência.

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Testi, Luca. "Tecnologie per la produzione di idrogeno da fonti rinnovabili." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/24892/.

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Il seguente elaborato analizza il ciclo di vita dell'idrogeno, a partire dal processo produttivo fino alle sue possibili applicazioni. In particolare si sofferma sulla produzione di idrogeno tramite elettrolisi e sulla sua applicazione all'interno di fuel cells nell'ambito dei trasporti, per ottenere ed utilizzare energia totalmente ad emissioni zero.

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Egute, Nayara dos Santos. "Estudo do processo para a aceleração da geração de amônia a partir de resíduos avícolas visando à produção de hidrogênio." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-12082011-155529/.

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O hidrogênio, utilizado em células a combustível, pode ser produzido a partir de diferentes espécies químicas, entre elas a amônia. O gás amônia como matéria prima para produção de H2 tem sido utilizado devido ao seu alto conteúdo energético e de hidrogênio, pela sua facilidade de decomposição, grande disponibilidade, baixo custo, pelas baixas pressões de armazenamento e pelos subprodutos do processamento serem ambientalmente corretos. Uma das fontes de amônia são os sistemas produtivos de frango de corte e ovos. Nesses sistemas a amônia é gerada a partir da decomposição do ácido úrico encontrado na excreta das aves. O resíduo proveniente dos sistemas de frango de corte é a cama de frango e nos sistemas de produção de ovos é a excreta sem qualquer substrato. A caracterização desses resíduos foi realizada por meio das análises de Espectrometria de Fluorescência de Raios-X por Dispersão de Comprimento de Onda (WDXRF), Análise Elementar CHN, Termogravimetria e Cromatografia a gás acoplada à Espectrometria de massa GC/MS. Os fatores estudados e que influenciam a volatilização da amônia foram: teor de nitrogênio, tempo de criação, enzima urease, temperatura, pH e teor de umidade. Os resultados dos experimentos com a cama de frango e com a excreta permitem concluir que a manipulação dos seguintes parâmetros aumentaram a emissão de amônia: o pH, o teor de nitrogênio, o tempo de criação, idade das aves e acúmulo de excreta, enzima urease e a temperatura. A adição de diferentes quantidades de areia na excreta e de volumes de água na cama de frango inibiram a emissão de amônia. A variação da quantidade de material (cama ou excreta) e do volume do frasco utilizado como câmara incubadora não demonstraram alterações significativas para serem escolhidos como uma variável. Na comparação da cama de frango com a excreta, a excreta foi considerada mais adequada aos objetivos do trabalho, pois a concentração de amônia determinada nos experimentos foi maior nesse material. Devido à grande quantidade de cama de frango e de excretas resultantes dos processos de produção, o reaproveitamento dos resíduos avícolas para a obtenção de amônia se faz necessário para melhorar a qualidade do meio ambiente local. A possibilidade do aumento da emissão de amônia, verificada nesse trabalho, e a sua utilização em um sistema geração de amônia - produção de hidrogênio - célula a combustível, poderá produzir eletricidade no próprio empreendimento, reduzindo os gastos das granjas e destinando adequadamente esses resíduos. The hydrogen, utilized in fuel cells, can be produced from a variety of intermediate chemicals, between them, the ammonia. The ammonia gas as a raw material for the hydrogen production has been used due to its high energetic content, facility of decomposition, high availability, low prices, low storage pressure and its by-products are environmentally correct. One of the sources of ammonia is poultry and egg production systems. In these systems the ammonia is produced from the decomposition of uric acid present in the excreta of birds. The residue from the poultry-rearing farms is the broiler litter and from the egg production system is the excreta without any substrate. The characterization of these residues was performed using the Wavelength-Dispersive X-Ray Fluorescence (WDXRF), Elementary Analysis (CHN), Termogravimetry and GC/MS Gas chromatography/ Mass spectrometry. The studied factors which influence the ammonia volatilization were: nitrogen content, raising period, urease enzyme, temperature, pH and moisture content. The experiment results with poultry litter and excreta allow to conclude that the manipulation of the following parameters increased the ammonia emission: pH, nitrogen content, raising period, age of birds and excreta accumulation, urease enzyme and the temperature. The addition of different amounts of sand in the excreta and different volumes of water in the poultry litter inhibited the emission of ammonia. The variation of the quantity of material (broiler litter or excreta) and the volume of the flask used as incubator chamber showed no significant alterations to be chosen as a variable. The excreta was considered more appropriate than poultry litter for the objectives of this work due to the higher ammonia concentrations determined in this material. Due to the large amount of poultry litter and excreta from the production processes, the reuse of poultry residues to obtain ammonia is necessary to improve the quality of the local environment. The possibility of ammonia emission increment observed in this study, and its use in a system of ammonia generation - hydrogen production - fuel cell might produce electricity in the enterprise, reducing the expenses of the farms and providing a properly destination for these residues.

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Silva, Fellipe Sartori da [UNESP]. "Determinação do custo de energia gerada através da utilização de células a combustível de carbonato fundido e turbina a vapor em um ciclo combinado." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153118.

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Submitted by Fellipe Sartori da Silva null (fellipe_sartori@yahoo.com) on 2018-03-20T14:29:37Z No. of bitstreams: 1 Determinação do custo de energia gerada através da utilização de células a combustível de carbonato fundido e turbina a vapor em um ciclo combinado.pdf: 3065864 bytes, checksum: 1b28d8ca48a059ab95292517f0d2d616 (MD5) Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2018-03-21T13:25:41Z (GMT) No. of bitstreams: 1 silva_fs_me_guara.pdf: 3065864 bytes, checksum: 1b28d8ca48a059ab95292517f0d2d616 (MD5) Made available in DSpace on 2018-03-21T13:25:41Z (GMT). No. of bitstreams: 1 silva_fs_me_guara.pdf: 3065864 bytes, checksum: 1b28d8ca48a059ab95292517f0d2d616 (MD5) Previous issue date: 2018-02-07 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Os modelos energéticos atuais são baseados majoritariamente na utilização de combustíveis fósseis, os quais, além de serem fontes finitas, ainda geram gases poluentes que contribuem para o efeito estufa e, consequentemente, para o aquecimento global. As células a combustível, por possuírem alta eficiência de conversão, baixa emissão, simplicidade de operação e flexibilidade em sua utilização, vêm sendo estudadas como opção mais limpa de geração. A célula a combustível de carbonato fundido, em particular, além de ter vantagens estruturais por operar a alta temperatura, possui calor residual que pode ser aproveitado para cogeração. O presente trabalho propõe uma configuração de ciclo combinado de uma célula a combustível de carbonato fundido de 10 MW, que possui reforma interna de gás natural, com um ciclo a vapor que aproveita o calor residual da célula. A reforma a vapor do gás natural, simulada pelo software STANJAN Chemical Equilibrium Solver, apresentou valores satisfatórios de produção de H2 na temperatura de operação da célula. As análises energética e exergética, simuladas através do software Engineering Equation Solver (EES), apontaram aumentos nas respectivas eficiências globais de 4,8 e 4,6%, respectivamente. A análise exergoeconômica indicou custo de geração de 0,4679 USD/kWh, valor acima das tarifas nacionais. Entretanto, a análise de sensibilidade mostrou que plantas de grande porte com essa configuração podem ser economicamente competitivas em diferentes cenários. Current researches point to a significant increase in energy demand over the next few years. Energy models are mostly based on fossil fuels, which generates greenhouse gases that contribute to global warming. Thus, it becomes necessary to develop equipment and cycles that operate with greater efficiency, as well as new technologies of energy generation with both fossil and renewable sources. Fuel cells are being widely investigated due to their high conversion efficiency, low emissions, structural simplicity and flexibility. Among several fuel cell types, molten carbonate fuel cell has advantages such as fuel flexibility and high operating temperature, which leads to high thermal energy residue. This residue can be used for cogeneration and combined cycles, in order to enhance the global efficiency. This study aimed to introduce a 10 MW internal reforming molten carbonate fuel cell and steam turbine combined cycle. Steam reforming of natural gas was simulated by STANJAN Chemical Equilibrium Solver and presented satisfactory H2 production at MCFC operating temperature. Simulation in Engineering Equation Solver (EES) of energetic and exergetic analysis showed efficiency increases of 4,8 and 4,6%, respectively. Exergoeconomic analysis pointed to a 0,4679 USD/kWh power cost. However, sensitivity analysis showed that higher plants can achieve economic viability in different scenarios

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Senna, Roque Machado de. "Desenvolvimento e demonstração de funcionamento de um sistema híbrido de geração de energia elétrica, com tecnologia nacional composto por um módulo de células a combustível tipo PEMFC e acumulador chumbo ácido." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-24102012-083711/.

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Este trabalho apresenta a contribuição obtida no desenvolvimento de um Gerador de Eletricidade Híbrido (HYBRIDGEN), com tecnologia nacional, focado nos sistemas de terceira geração de energia elétrica híbrido, composto por um módulo de células a combustível tipo PEMFC, associado a um acumulador chumbo ácido. Mostra-se também a sua capacidade de operar em modo contínuo, carga com demanda variável e fator de carga inferior a 50%. Foram abordados quatro temas principais. O primeiro refere-se a um estudo para a melhoria da eficácia na conversão de energia em corrente contínua (cc), ao regular o potencial de saída do conversor cc-cc. A energia é proveniente do módulo de célula a combustível de 1 kWe, equipado com sistema térmico de refrigeração e sistema de alimentação de gases, aqui denominados MCC1. Para tal, foi construído o modelo matemático do sistema conversor de corrente contínua (sistema conversor cc-cc), com solução suportada em equações diferenciais algébricas, ensaios no MCC1, bem como em simulação computacional no programa MATLAB7®. O segundo tema refere-se ao desenvolvimento do projeto e montagem do protótipo do HYBRIDGEN devido à inexistência no mercado brasileiro de um equipamento com as características necessárias tanto para a pesquisa, quanto para uso comercial. Desenvolveu-se uma placa controladora para o acumulador (PCC), os esquemas elétricos, os barramentos e o sistema de relés. Também foi utilizado o MCC1 em desenvolvimento pelo IPEN e ELECTROCELL® com tecnologia 100% nacional. O HYBRIDGEN foi instalado em um sistema móvel. O terceiro tema refere-se à análise de estabilidade do modelo matemático do sistema conversor cc-cc. Utilizou-se de quatro testes de estabilidade, sendo: 1 - pela Resposta em Frequência ao utilizar o Teorema do Mapeamento, de Nyquist; 2 - Lugar das Raízes, de Nyquist; 3 - função de teste Degrau, em pontos de operação e, 4 - função de teste Impulso, em pontos de operação. Por fim, apresentaram-se os resultados dos ensaios de potencial e corrente de uma célula a combustível unitária de 25 cm2, do MCC1, e do HYBRIDGEN. No desenvolvimento dos primeiros testes o MCC1 atingiu 704,55 We, (potência considerada condição predominante de operação). A seguir, demonstrou-se a capacidade do HYBRIDGEN para simultaneamente: alimentar cargas em corrente contínua; carregar o acumulador de 45 Ah; alimentar o inversor de 2 kWe e o autotransformador, para fornecer energia a equipamentos em 12Vcc, 127 Vac e 220Vac, 60 Hz, todos num total de 819,52 We. Esses resultados foram obtidos mesmo com limitações na refrigeração ventilada do MCC1, observadas no decorrer dos testes. Assim, o HYBRIDGEN se mostrou viável tecnicamente, e com grande potencial de uso. This work presents the contribution obtained by the development of the Hybrid Electric Power Generation System (HYBRIDGEN), with Brazilian technology, focused on third generation hybrid system, composed of the fuel cell type PEMFC, associated with a lead acid battery, and shows its variable load demand continuous mode operate ability with load factor below 50%. Four main themes were addressed. The first refers to a study concerning the to direct current (DC) energy converting efficiency improvement to regulate the dc-dc converter output potential. Power comes from the 1 kWe fuel cell stack, equipped with thermal cooling system and gas supply system, here named MCC1. After that a dc-dc converter system mathematical model was built supported on differential algebraic equations solution, the MCC1 trials, as well as in MATLAB7® program computer simulation. The second theme concerns the HYBRIDGEN prototype project and assembly due to lack on equipment on the Brazilian market with the necessary features for both research and for commercial use. Then, a charge controller card (CCC), wiring diagrams, copper bus and relay system were developed. A MCC1 developed by IPEN and ELECTROCELL® with Brazilian technology was use. The HYBRIDGEN can be installed in a mobile system. The third refers to a study concerning the stability analysis of the dc-dc converter system mathematical model. Four stability tests were addressed, namely: 1- The Frequency Response was used the Nyquist Mapping Theorem, 2 - The Nyquist Root Locus , 3 - The Step Test Function on operating points, and 4 - The Impulse Test Function on operating points. Finally, experiments with a 25 cm2 fuel cell unit, the MCC1 module and the HYBRIDGEN were carried out to, potential and current results. In the first MCC1 tests delivered a power output of 704.55 W (considered dominant operation power). Then, it was demonstrated the HYBRIDGEN ability to 819.52 We supply power, simultaneously: direct current loads, charge a 45Ah battery, a 2 kWe inverter and the autotransformer to supply power 12 Vcc, 127Vac, 220Vac, 60 Hz equipment. These results were achieved despite the MCC1 limit in the cooling system observed during the tests. Then, the HYBRIDGEN could be demonstrated technically feasible, and leading to great potential uses.

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Santini, Itamar. "Análise de conversores CC-CC com alto ganho de tensão para aplicações com célula a combustível." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18153/tde-24012017-162247/.

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O presente trabalho aborda a análise e o desenvolvimento de conversores CC-CC com alto ganho de tensão, para aplicações com fontes de energia de baixíssima tensão, porém capazes de fornecer altas correntes, como: painéis fotovoltaicos, células a combustível e baterias. O principal objetivo deste trabalho é elevar a tensão de uma única célula a combustível até um nível adequado de tensão para realizar a carga de uma bateria com tensão nominal de aproximadamente 12 V, de modo eficiente, com baixa ondulação na corrente de entrada do conversor e com baixa ondulação na tensão de saída. Para alcançar o objetivo proposto, dezenas de topologias de conversores foram estudadas, analisadas, simuladas e implementadas. O trabalho também apresenta uma comparação entre topologias de conversores CC-CC que realizam a transferência de energia por meio de indutores acoplados, com uma topologia de conversor que opera com transferência direta de energia por meio de um transformador. Por fim, os resultados experimentais são apresentados com o intuito de validar os resultados simulados e teóricos. This work shows the analysis and development of DC-DC converters with high voltage gain, for applications with energy sources of low input voltage, but capable of providing high currents, such as: photovoltaic panels, fuel cells and batteries. The main objective of this work is to raise the voltage of a single fuel cell to a suitable vol-tage level to efficiently charge a battery with rated voltage of approximately 12 V, with low current ripple in the converter and with low output voltage ripple. To achieve the proposed objective, dozens of topologies of converters were studied, analyzed, simulated and implemented. This work shows a comparison between topologies of DC-DC converters that perform power transfer via coupled inductors, with a converter topology operating with direct energy transfer through a transformer. Finally, experimental results are presented in order to validate the theoretical and simulated results.

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de, la Torre Jorge. "FUEL CELLS: HYPE OR REALITY? OVERVIEW OF FUEL CELL TECHNOLOGIES FEASIBILITY STATUS WITH AN EMPHASIS ON AUTOMOTIVE AND RESIDENTIAL PROTON EXCHANGE MEMBRANE FUEL CELLS (PEMFCs)." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1309540374.

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Ferreira, Andre Augusto. "Sistema supervisorio de gestão de multiplas fontes de suprimento para aplicações em veiculos eletricos." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260860.

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Orientador: Jose Antenor Pomilio Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação Made available in DSpace on 2018-08-09T17:49:15Z (GMT). No. of bitstreams: 1 Ferreira_AndreAugusto_D.pdf: 4648060 bytes, checksum: fec10ea5d77379b209259bd3174d9224 (MD5) Previous issue date: 2007 Resumo: Este trabalho propõe uma estratégia de gestão de energia, para aplicações em veículos elétricos, baseado em um sistema supervisório nebuloso que combina três diferentes fontes de suprimento, em termos de densidade de energia e de densidade de potência, a saber: célula a combustível, bateria e supercapacitor. O sistema supervisório coordena o fluxo de potência entre os dispositivos de suprimento de energia e provê elevada qualidade de energia necessária para um bom desempenho do sistema de propulsão do veículo elétrico. A estratégia proposta de gestão de energia do conversor eletrônico com múltiplas entradas possibilita o controle individual da transferência de potência das fontes de suprimento, em suas melhores regiões da atuação. Um conveniente arranjo entre as fontes e alocação dos recursos disponíveis permite reduzir o dimensionamento da célula a combustível. Adicionalmente, a vida útil destas fontes e a imunidade do sistema de suprimento a variações bruscas de demanda de potência são melhoradas. Um protótipo de 3 kW é simulado e avaliado experimentalmente, incluindo um banco de baterias de chumbo-ácido e supercapacitor, para comprovar a eficácia da estratégia de controle proposta Abstract: This work introduces an Energy Management strategy, for electrical vehicle applications, based on a fuzzy logic supervisory system that is able to combine three different power supply sources, i. e., fuel cell, battery and supercapacitor. The supervisory system coordinates the power flow between the power sources so that the system is able to provide high power quality, which is needed to achieve the desirable dynamic performance of the propulsion system. The proposed energy management strategy of a multiple input power electronic converter takes advantage of the individual characteristics of each power sou rce and makes than operate atthe best operation region. Through adequate power sources arrangements and use of the available resources, the fuel cell size is reduced. In addition, the power sources¿ life time and the system ride-through at sudden load disturbances are increased. Simulation and experimental results of a 3 kW prototype, with real supercapacitor and lead-acid batteries bank, prove that the fuzzy logic is a suitable energy management control strategy Doutorado Automação Doutor em Engenharia Elétrica

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Costa, Luzia Bouzan Oliveira. "Avaliação do ciclo de vida da produção de biogás via estação de tratamento de esgoto e uso em célula a combustível de óxido sólido." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-24102012-080923/.

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A busca pelo uso de energia renovável, bem como a mitigação dos impactos antropogênicos, desempenha importante papel no desenvolvimento da sociedade contemporânea. O uso de energia de origem renovável é uma possível solução para os problemas relacionados aos impactos ambientais, em especial, às alterações climáticas. Uma importante fonte de energia renovável é a biomassa oriunda de resíduos orgânicos que, após a digestão anaeróbia, resulta em um gás rico em metano, conhecido como biogás. Sob o ponto de vista de qualidade ambiental, o aproveitamento energético dos resíduos produzidos a partir do tratamento das águas residuárias domésticas pode minimizar os impactos ambientais à medida que permite a diminuição da carga orgânica descartada na água e no solo. Adicionalmente, também é possível mitigar os efeitos negativos de emissões de metano na atmosfera quando o biogás é utilizado na produção de energia por meio das células a combustível (CaC) do tipo óxido sólido (SOFC). Neste sentido, o presente trabalho objetivou avaliar o ciclo de vida da ETE, da unidade geradora de biogás, sua purificação e uso em CaCs, identificando o potencial de mitigação dos gases do efeito estufa e de aproveitamento energético do biogás. Dentre os principais resultados obtidos, a etapa construtiva, é a principal contribuinte da demanda acumulada de energia, participando com 55% da CED, enquanto a etapa de tratamento do esgoto, fase líquida, destaca-se na produção de emissões atmosféricas, cerca de 23.500 Kg CO2 eq por dia. O potencial de emissões dos gases de efeito estufa podem ser evitados, durante todo o ciclo, em cerca de 3.000 kg CO2 eq por dia. A energia total que pode ser aproveitada com o biogás gerado na ETE e usado em CaC, do tipo SOFC, é de cerca de 14.000 kWh/dia, o que pode suprir em 100% a demanda de eletricidade da fase de tratamento. Os resultados apresentados lançam um desafio e geram oportunidades para pesquisadores e planejadores de sistemas energéticos desenvolverem estratégias ambientalmente saudáveis para a utilização dos recursos renováveis. The search for renewable energy use and mitigation of anthropogenic impacts play an important role in the development of contemporary society. The use of energy from renewable sources is a possible solution to the problems related to environmental impacts, in particular, climate change. An important renewable energy source is biomass deriving from organic waste, after the anaerobic digestion, resulting in a gas rich in methane, known as biogas. From the point of view environmental quality, energy recovery of waste generated from the treatment of domestic wastewater can minimize environmental impacts as it allows the reduction of organic load dropped in water and soil. Additionally, it is also possible to mitigate the negative effects of methane emissions in the atmosphere when the biogas is used in the production of energy through solid oxide fuel cells (SOFC). In this sense, this study aimed at assessing the life cycle of a Wastewater Treatment Plant (WWTP), the biogas-generating unit, its purification and fuel cells use by identifying the potential mitigation of greenhouse gases and energy use of biogas. Among the main results obtained, the constructive phase is the main contributor to the cumulative energy demand, accounting for 55% of the CED, while in the step of sewage treating its particularly important the production of atmospheric emissions, about 23,500 kg CO2eq per day. The potential for emissions of greenhouse gases can be avoided throughout the cycle, at around 3,000 kg CO2eq per day. The total energy that can be produced with the biogas generated in WWTP and burned in the SOFC is approximately 14,000 kWh/day, which can provide 100% of the power demand of the treatment phase. The results presented launch challenges and generate opportunities for researchers and energy systems planners to develop strategies for environmentally healthy use of renewable resources.

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18

NASCIMENTO, Aldreany Pereira do. "Estudo de uma célula a combustível hidrogênio/ar de 1 kW de eletrólito membrana polimérica." Universidade Federal de Campina Grande, 2016. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/290.

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Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-03-15T16:40:52Z No. of bitstreams: 1 ALDREANY PEREIRA DO NASCIMENTO - DISSERTAÇÃO PPGEQ 2016..pdf: 4384493 bytes, checksum: 8cf20c9f79749f12b562389c82ec5d3f (MD5) Made available in DSpace on 2018-03-15T16:40:52Z (GMT). No. of bitstreams: 1 ALDREANY PEREIRA DO NASCIMENTO - DISSERTAÇÃO PPGEQ 2016..pdf: 4384493 bytes, checksum: 8cf20c9f79749f12b562389c82ec5d3f (MD5) Previous issue date: 2016-10-30 Capes A crise do petróleo juntamente com a grande necessidade de novas fontes de energias sustentáveis leva ao desenvolvimento de tecnologias mais limpas e eficientes. Neste contexto, as células a combustível aparecem como uma das soluções promissoras para a geração de energia elétrica, tendo como produto da reação, basicamente água e calor. Este trabalho de dissertação consiste na caracterização de uma célula a combustível PEM (Polymer Electrolyte Membrane) alimentada com hidrogênio e ar para a conversão de energia elétrica da energia química contida no gás hidrogênio. A célula a combustível utilizada é de potência nominal de 1 kW, constituída por 72 células ligadas em série com um sistema de controle próprio. A caracterização é feita através da utilização de uma carga resistiva configurável com base num microcontrolador. A partir dos parâmetros registrados (corrente e tensão), a curva de polarização, a densidade de corrente e a eficiência foram calculadas com base nos sistemas de curto circuito ligado e desligado (SCU: ON e SCU: OFF, respectivamente). Os resultados mostram uma potência máxima de saída de aproximadamente 623 W (37,09 V, 16,78 A), e uma densidade de corrente de 209,75 mA/cm2, com uma eficiência operacional em torno de 42 %, com o sistema de SCU: OFF. Para o sistema SCU: ON a potência máxima de saída é em torno de 664 W (39,10 V, 17,81 A) com densidade de corrente de 222,62 mA/cm2 e uma eficiência operacional de 44 %. O sistema de carga variável mostrou-se satisfatório para testar a célula, com um desvio entre a potência nominal e a real inferior a 20 %. Os relativamente baixos valores de eficiência do sistema (<20 %) são explicados pelo tempo de vida da célula. The use of new sustainable energy sources is dependent on the development of clearer and more efficient technologies. Therefore, the fuel cells appear like a promising solution for the electrical energy generation, since that the reaction products are water and heat. This work plans to characterize a polymer electrolyte membrane fuel cell, feeding with hydrogen and air. The tested 1 kW nominal power fuel cell is constituted by 72 cells connected in serial. The characterization is made using a variable resistive charge system. It comprises 64 resistors (20 W) together with blowers for cooling. From the electrical parameters (voltage and current), the polarization curve, the current density and the efficiency of the fuel cell were calculated, with the short-circuit system on and off (SCU: ON and SCU: OFF). A maximum output power of 623 W (37.09 V and 16.78 A), with a current density of approx. 209.75 mA/cm2 and an efficiency around 42 % are obtained when the SCU is OFF. With the SCU: ON, the values are 664 W (39.10 V and 17.81 A), 222.62 mA/cm2 and 44 %, respectively. The results show that the resistive charge system is appropriate to test this kind of fuel cell. The low global efficiency values (< 20 %) can be explained by the fuel cell age.

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19

Mignani, Andrea. "Prospettive per le future tecnologie in ambito automotive." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21457/.

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Gli ultimi decenni hanno visto un notevole incremento dell'attenzione verso temi quali i cambiamenti climatici, le energie alternative, le emissioni inquinanti e climalteranti. L'analisi riportata cerca di individuare quali tecnologie possano ragionevolmente risultare più idonee nell'affrontare e risolvere le problematiche legate, in generale, al settore dei trasporti ed, in particolare, a quello automotive. Le tecnologie analizzate riguardano veicoli dotati di tradizionali Motori a Combustione Interna (MCI), Veicoli Elettrici a Batteria (BEV) e Veicoli a Celle a Combustibile (FCV). Per ognuna di queste tre modalità di propulsione si è messo in evidenza il livello tecnologico odierno, con i relativi punti di forza e le difficoltà attuali in termini di prestazioni, costi del sistema e delle infrastrutture. Ci si è inoltre concentrati sulle possibili future soluzioni tecnologiche che in prospettiva potranno rendere ogni diverso sistema di propulsione sempre più competitivo sul mercato mondiale, cercando un compromesso tra prestazioni, consumi, costi ed impatto ambientale. Tutto lo studio ha come principale linea guida una particolare attenzione al tema ambientale in quanto risulta ormai evidente come negli ultimi anni questo aspetto abbia assunto un'importanza tale da essere messo al centro non solo della vita di ogni singolo cittadino, ma anche delle iniziative dei governi e, di conseguenza, delle strategie delle diverse aziende appartenenti ad ambiti anche molto differenti tra loro.

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20

Calder, Michael Alexander. "Modeling of a Microbial Fuel Cell." Thesis, Norwegian University of Science and Technology, Department of Energy and Process Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-8837.

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It is clear that society worldwide must immediately begin to mitigate its environmental damage in order to sustain life on Earth. In this regard, researchers all over the global are exploring new energy efficient alternatives to power everything from cars to cell phones. The following brief describes research conducted on Microbial Fuel Cells (MFC) and its ability to utilize bacteria to produce electricity from biological masses for low energy consumer products While structurally the MFC is very similar to a Conventional Fuel Cell, the two systems have inherent differences that change the reactions, inputs and energy output. Currently, we have found MFC to produce only a fraction of the power (~1A/cm2 vs ~1mA/ cm2 ) produced by a conventional CFC, however, its versatility keeps MFCs as a promising fuel source potential. A Multi-disciplinary University Research Initiative has organized to examine and test the potential of MFC. The team is divided into three teams based on industry domains and expertise: microbiology, chemistry and electrochemistry, and engineering and modeling. The followin master thesis research was part of the engineering and modeling team lead by Professor Ronney XX. The goal of our team was to construct a first version of a computational model simulating the MFC system. The computational model is be based on combustion kinetics and a diffusion-reaction system theories, and is manipulated to immatate a biological system that can maximize its energy output. The model has been constructed in Fluent. Starting out with a 1D model, and consequently moved on to a 2D version. The final model is a diffusion-reaction system with 6 different species, a 3-step reaction, including a bacterial anodic oxidation, a cathodic reduction, and a possibility of taking into account a counteracting anodic reaction for oxygen crossover through the membrane. While the model has been proven to correlate well with lab tested experimental results, the team will continue to identify conditions to maximize the MFCs efficiency and energy output.

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21

Buche, Silvain. "Polymer electrolyte fuel cell diagnostics." Thesis, University of Bath, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285318.

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22

Swedenborg, Samuel. "Modeling and Simulation of Cooling System for Fuel Cell Vehicle." Thesis, Uppsala universitet, Elektricitetslära, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-326070.

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This report is the result of a master’s thesis project which covers the cooling system in Volvo Cars’ fuel cell test vehicle. The purpose is to investigate if the existing cooling system in the fuel cell test vehicle works with the current fuel cell system of the vehicle, in terms of sufficient heat rejection and thus sustaining acceptable temperature levels for the fuel cell system. The project also aims to investigate if it is possible to implement a more powerful fuel cell system in the vehicle and keep the existing cooling system, with only a few necessary modifications. If improvements in the cooling system are needed, the goal is to suggest improvements on how a suitable cooling system can be accomplished. This was carried out by modeling the cooling system in the simulation software GT-Suite. Then both steady state and transient simulations were performed. It was found that the cooling system is capable of providing sufficient heat rejection for the current fuel cell system, even at demanding driving conditions up to ambient temperatures of at least 45°C. Further, for the more powerful fuel cell system the cooling system can only sustain sufficient heat rejection for less demanding driving conditions, hence it was concluded that improvements were needed. The following improvements are suggested: Increase air mass flow rate through the radiator, increase pump performance and remove the heat exchanger in the cooling system. If these improvements were combined it was found that the cooling system could sustain sufficient heat rejection, for the more powerful fuel cell system, up to the ambient temperature of 32°C.

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23

Nilsson, Henrik. "Vätgas och bränsleceller : Ny energi för Försvarsmakten?" Thesis, Swedish National Defence College, Swedish National Defence College, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-106.

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The purpose of this paper is to identify the current status of fuel cell technology and to establish whether said technology is mature enough to be implemented into the Swedish Armed Forces. The question to be answered in this paper is as follows: Can hydrogen gas and fuel cells be used as an alternative source of energy within the Swedish Armed Forces?This paper is based on theoretical studies and reports from prior research done on fuel cells. By studying these facts a predictive answer has been obtained. The answer I have come to, is that the maturity of fuel cell technology is currently inadequate for the Swedish Armed Forces to implement, especially considering its harsh working conditions.

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24

Mirzababaei, Jelvehnaz. "Solid Oxide Fuel Cells with Methane and Fe/Ti Oxide Fuels." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1415461807.

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25

Kim, Hyea. "High energy density direct methanol fuel cells." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37106.

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The goal of this dissertation was to create a new class of DMFC targeted at high energy density and low loss for small electronic devices. In order for the DMFC to efficiently use all its fuel, with a minimum of balance of plant, a low-loss proton exchange membrane was required. Moderate conductivity and ultra low methanol permeability were needed. Fuel loss is the dominant loss mechanism for low power systems. By replacing the polymer membrane with an inorganic glass membrane, the methanol permeability was reduced, leading to low fuel loss. In order to achieve steady state performance, a compliant, chemically stable electrode structure was investigated. An anode electrode structure to minimize the fuel loss was studied, so as to further increase the fuel cell efficiency. Inorganic proton conducting membranes and electrodes have been made through a sol-gel process. To achieve higher voltage and power, multiple fuel cells can be connected in series in a stack. For the limited volume allowed for the small electronic devices, a noble, compact DMFC stack was designed. Using an ADMFC with a traditional DMFC including PEM, twice higher voltage was achieved by sharing one methanol fuel tank. Since the current ADMFC technology is not as mature as the traditional DMFCs with PEM, the improvement was accomplished to achieve higher performance from ADMFC. The ultimate goal of this study was to develop a DMFC system with high energy density, high energy efficiency, longer-life and lower-cost for low power systems.

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26

Hull, Brent. "Fuel cell mositure and energy recovery." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/16428.

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27

Ospina, Alvarado Angelica Maria. "Holistic Analysis of Fuel Cells for Residential Application." Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19746.

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The development of an index to compare different sources of energy is presented; the index address the appraisal of the source of energy from its sustainable performance and also using the factors that influence the user's decision making process of adopting an alternative energy. The index is used to compare the fuel cell system and the traditional grid system powered by coal fired power plants, for a typical residential unit located in the rural Appalachian region in Ohio.

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28

Laguna, Bercero Miguel A. "Hydrogen and fuel cells: an efficient and clean energy alternative." Revista de Química, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/100084.

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El avance tecnológico más importante de las próximas décadas pasa por el uso del hidrógeno como combustible, sustituyendo el consumo masivo de los combustibles fósiles. De esta manera, utilizando tecnologías basadas en pilas de combustible, conseguiremos sistemas energéticos más eficientes que los actuales y, además respetuosos, con el medio ambiente. The most important technological development in the coming decades will be the use of hydrogen as an alternative to the widely used fossil fuels. By the use of fuel cell based technologies, it will be feasible to produce energy systems that will be more efficient than the current ones and that will also be environmentally friendly.

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29

Hedström, Lars. "Fuel Cells and Biogas." Doctoral thesis, KTH, Energiprocesser, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-13219.

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This thesis concerns biogas-operated fuel cells. Fuel cell technology may contribute to more efficient energy use, reduce emissions and also perhaps revolutionize current energy systems. The technology is, however, still immature and has not yet been implemented as dominant in any application or niche market. Research and development is currently being carried out to investigate whether fuel cells can live up to their full potential and to further advance the technology. The research of thesis contributes by exploring the potential of using fuel cells as energy converters of biogas to electricity. The work includes results from four different experimental test facilities and concerns experiments performed at cell, stack and fuel cell system levels. The studies on cell and stack level have focused on the influence of CO, CO2 and air bleed on the current distribution during transient operation. The dynamic response has been evaluated on a single cell, a segmented cell and at stack level. Two fuel cell systems, a 4 kW PEFC system and a 5 kW SOFC system have been operated on upgraded biogas. A significant outcome is that the possibility of operating both PEFCs and SOFCs on biogas has been established. No interruptions or rapid performance loss could be associated with the upgraded biogas during operation. From the studies at cell and stack level, it is clear that CO causes significant changes in the current distribution in a PEFC; air bleed may recover the uneven current distribution and also the drop in cell voltage due to CO and CO2 poisoning. The recovery of cell performance during air bleed occurs evenly over the electrode surface even when the O2 partial pressure is far too low to fully recover the CO poisoning. The O2 supplied to the anode reacts on the anode catalyst and no O2 was measured at the cell outlet for air bleed levels up to 5 %. Reformed biogas and other gases with high CO2 content are thus, from dilution and CO-poisoning perspectives, suitable for PEFC systems. The present work has enhanced our understanding of biogas-operated fuel cells and will serve as basis for future studies. QC20100708

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30

Troughton, Gavin L. "Anodes for the direct methanol fuel cell." Thesis, University of Newcastle Upon Tyne, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335195.

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31

Mwinga, Makani. "Design and development of a fuel cell power supply unit." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2524.

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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2017. Fuel cell (FC) technology is one of the most sought-after renewable energy technology. However, the output voltage of FC stacks is inherently unstable; as such, it is of little or no use for most power supply applications. In addition to the unstable output voltage, FC stacks are susceptible to high current ripple, which can reduce the system’s life expectancy. The work carried out in order to stabilise the output voltage, and to reduce the current ripple of FC stacks involves a review of some existing converter topologies used for power conditioning units (PCUs), modelling, design, control and simulation of different converter topologies and the experiment of the prototype circuit for the interleaved boost voltage multiplier (IBVM) converter topology. In the process to stabilise the stack output voltage and to reduce the stack output current ripple, it is also required to improve the system response to load changes. This work presents results that show that system works, with the voltage stabilised, the stack output current ripple reduced and the response time reduced. A relative evaluation of the dynamic behaviour of four converter topologies in power conditioning units is carried out, and these are the isolated current-fed full-bridge (ICFFB) converter, the boost converter, the sepic converter and the IBVM converter. The simulation results of the four topologies show that the output voltage of a PEMFC stack was stabilised, and that the IBVM topology is a better topology compared to the others, especially when it comes to reducing the stack current ripple.

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32

Aaron, Douglas Scott. "Transport in fuel cells: electrochemical impedance spectroscopy and neutron imaging studies." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34699.

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Current environmental and energy sustainability trends have instigated considerable interest in alternative energy technologies that exhibit reduced dependence on fossil fuels. The advantages of such a direction are two-fold: reduced greenhouse gas emissions (notably CO2) and improved energy sustainability. Fuel cells are recognized as a potential technology that achieves both of these goals. However, improvements to fuel cell power density and stability must be realized to make them economically competitive with traditional, fossil-based technologies. The work in this dissertation is largely focused on the use of analytical tools for the study of transport processes in three fuel cell systems toward improvement of fuel cell performance. Polymer electrolyte membrane fuel cells (PEMFCs) are fueled by hydrogen and oxygen to generate electrical current. Microbial fuel cells (MFCs) use bacteria to degrade carbon compounds, such as those found in wastewaters, and simultaneously generate an electric current. Enzyme fuel cells (EFCs) operate similarly to PEMFCs but replace precious metal catalysts, such as platinum, with biologically-derived enzymes. The use of enzymes also allows EFCs to utilize simple carbon compounds as fuel. The operation of all three fuel cell systems involves different modes of ion and electron transport and can be affected negatively by transport limitations. Electrochemical impedance spectroscopy (EIS) was used in this work to study the distribution of transport resistances in all three fuel cell systems. The results of EIS were used to better understand the transport resistances that limited fuel cell power output. By using this technique, experimental conditions (including operating conditions, construction, and materials) were identified to develop fuel cells with greater power output and longevity. In addition to EIS, neutron imaging was employed to quantify the distribution of water in PEMFCs and EFCs. Water content is an integral aspect of providing optimal power output from both fuel cell systems. Neutron imaging contributed to developing an explanation for the loss of water observed in an operating EFC despite conditions designed to mitigate water loss. The findings of this dissertation contribute to the improvement of fuel cell technology in an effort to make these energy devices more economically viable.

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33

Wang, Ying-Chin. "Using Red Blood Cells in Microbial Fuel Cell Catholyte Solution to Improve Electricity Generation." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1398945679.

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34

González, Guerrero MªJosé. "Enzymatic microfluidic fuel cells: from active to passive power sources." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/322082.

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Esta tesis presenta el desarrollo y la fabricación de pilas de combustibles microfluídicas para aplicaciones portátiles de baja potencia. En concreto, pilas biológicas que utilizan las enzimas en la degradación de la glucosa. El trabajo está dividido en dos secciones dependiendo de si los dispositivos fabricados son activos, es decir, los reactivos son suministrados a la micropila por bombeo (Capítulo 2 y 3). O si por el contrario los reactivos fluyen sin necesidad de mecanismos externos los dispositivos serán pasivos (Capítulo 4 y 5). En el primer capítulo de la tesis se ha llevado a cabo la primera aproximación en el desarrollo de micro pilas de combustible glucosa/O2 con el objetivo de hacer posible las primeras medidas electroquímicas con enzimas. La pila microfluídica fue construida sobre un sustrato de vidrio en el cual se grabaron electrodos de oro mediante técnicas de microfabricación. Por otro lado, se utilizó fotolitografía suave para la fabricación de los canales (con forma de Y) en PDMS. Esta forma de canal permitió fluir dos soluciones en paralelo usando una bomba de jeringa. Como primera aproximación, las enzimas se encontraban fluyendo de manera continua a través del canal. Eso provocaba experimentos caros y dificultaba su posible aplicación portátil. De este modo, el siguiente aspecto en abordarse fue la inmovilización de los biocatalizadores sobre los electrodos de la micro pila. El Capítulo 2 presenta la fabricación de una pila de combustible que posee los biocatalizadores inmovilizados en la superficie de los electrodos lo cual hace que los biocatalizores sean aprovechados más eficientemente que en la anterior pila. Los electrodos se han fabricado utilizando resina pirolizada y se han usado por primera vez con éxito en pilas microfluídicas enzimáticas de este tipo. La pila está compuesta por diferentes capas de material plástico laminado que han sido cortadas usando un plotter de corte. Esto hace que la fabricación del dispositivo sea rápida, barata y compatible con la manufacturación a gran escala. El canal microfluídico se ha definido también sobre este tipo de material plástico, evitando el largo proceso litográfico relacionado con el PDMS. Por otro lado, el canal (en forma de Y) permite optimizar la potencia que obtenemos de la pila cuando bombeamos dos soluciones diferentes. Por otro lado, el dispositivo necesita ser simplificado para finalmente obtener una fuente de energía portátil. Con este objetivo se abordó la siguiente fase de la tesis. El Capítulo 4 describe la fabricación de una pila microfluídica implementada utilizando sustratos de papel a través de los cuales fluyen los reactivos (de manera pasiva) por efecto capilar. Los componentes de la pila se cortaron utilizando un plotter de corte, lo que permitía fabricar dispositivos con mucha rapidez. Se probó el buen funcionamiento de una pila de combustible de papel y enzimática obteniendo valores de potencia similares a los presentados en el Capítulo 3 (donde las soluciones eran bombeadas). A partir de aquí el trabajo se centró en aproximar la pila de papel a la simplicidad de los test de flujo lateral. Así que la micro pila fue adaptada y operada con éxito usando una única solución, generando energía de una bebida comercial. El Capítulo 5 presenta una micropila de combustible fabricada en papel mucho más sofisticada y pequeña que la del capítulo anterior. Se probó satisfactoriamente una nueva combinación de biocatalizadores que permitió trabajar utilizando muestras a pH neutro. Además, el tamaño compacto del sistema abrió la posibilidad de operar la pila de combustible con fluidos fisiológicos como por ejemplo la sangre. Finalmente, se ha demostrado que es posible tener una pila preparada para alimentar dispositivos que requieran poca demanda de energía. Sin embargo, todavía se deben hacer esfuerzos para acercar esta pila a un mundo real, debido principalmente a que el tiempo de vida de las enzimas es todavía limitado. This thesis presents the development and fabrication of microfluidic fuel cells for low power and portable applications. Specifically, biological fuel cells that use enzymes for glucose degradation. This work is divided in two sections depending on whether the fabricated devices are active, i. e. the reagents are supplied into the micro fuel cell by pumping (Chapters 2 and 3). If, on the contrary, the reagents flow without needing external mechanisms they are passive devices (Chapters 4 and 5). In the first chapter of the thesis the first approach in the development of glucose/O2 micro fuel cells was conducted in order to allow for the initial electrochemical measurements with enzymes. The microfluidic fuel cell was fabricated using a glass substrate in which gold electrodes were impressed using microfabrication techniques. On the other hand, soft lithography was used to fabricate the Y-shaped PDMS channels. This channel shape enabled to flow two solutions in parallel using a syringe pump. The enzymes were continuously flowing through the channel causing expensive experiments in addition to hindering its possible portable application. Thereby, the biocatalysts immobilization on the electrodes was next addressed in this thesis. Chapter 2 presents the fabrication of a micro fuel cell with enzymes trapped on the electrode surfaces which lead to an effective use of the biocatalysts. The electrodes were fabricated using pyrolyzed resists and were successfully used for the first time in enzymatic microfluidic fuel cells of this kind. The fuel cell was formed by different layers of plastic laminated materials cut using a cutter plotter. This promotes a fast and inexpensive device fabrication which is compatible with large scale manufacturing. The microfluidic channel was also defined on this type of plastic materials, thus avoiding the long lithographic process related to the PDMS. Moreover, this Y-shaped channel allows to optimize the power obtained from the fuel cell when two different solution are pumped into the system. Therefore, the following aspect to be addressed was the biocatalyst immobilization over the electrodes of the micro fuel cell Chapter 4 describes the construction of a microfluidic fuel cell fabricated using paper substrates. The reagents flow through this paper (in a passive way) by capillary action. The fuel cell components were cut using a cutting plotter which allows fabricating devices much faster. The proper functioning of this paper-based microfluidic fuel cell was verified obtaining similar power values to those presented in Chapter 3 (were solution were pumped). From here, the work focused on bringing the paper fuel cell closer to the simplicity of lateral flow tests. The fuel cell was then adapted and successfully operated using a single solution, generating energy from a commercial drink. Chapter 5 presents a microfluidic paper-based fuel cell smaller and more sophisticated than the one presented in previous chapter. A new combination of enzyme was tested which allowed to work with samples at neutral pH. Additionally, the compact size of the system opened the possibility to operate the paper fuel cell with physiological fluids, such as blood. Finally, it was demonstrated that was possible to have a fuel cell ready to fed devices demanding low energy. However, more efforts have to be done in the field to approach this fuel cell to a real world mainly due to the still limited lifetime of the enzymes.

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35

Cameli, Fabio. "Microbial Fuel Cell for Waste Water Treatment." Thesis, KTH, Skolan för kemivetenskap (CHE), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-183074.

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Microbial Fuel Cell is a novel technology that can be used for a waste water treatment in order to simultaneously remove carbonaceous matter and nitrogen while producing electrical power. Even if it is not an established technology so far, MFC could be a cost effective option for waste water treatment and the major challenge of this process will be the device scale-up. Exoelectrogenic bacteria are capable of converting the chemical energy of organic matter into electrical energy by transferring the electrons produced in the oxidation to the anode electrode. This project focused on developing a single device for nitrification, denitrification and carbon removal. Two double air-cathode single chamber MFCs are used to test the feasibility of this process that could replace the biological unit in a waste water treatment train. The cells tested in this study were manufactured with the purpose of achieving a high surface area on both the anode electrode (vitreous carbon foam) and the air-cathode electrodes (metallic mesh with diffusion layer and active layer) with different catalysts for the reduction reaction (cobalt and platinum). The bacterial biofilm growth is a fundamental step and the cells Open Circuit Potential was monitored during all the start-up period to determine the microorganism acclimation: a three days lag period was observed in both cells before the potential rise. The second cell was forced to reach higher voltage through an anode polarization and that seems to positively affect the biofilm stability at lower voltages transferring a greater amount of electrons and hence obtaining a higher current and power generation. For this reason after three weeks of inoculation the second cell reached an open circuit potential of 0.76 V which is a promising value for such a system. Electrochemical and biological tests were conduced in order to test the power production of the cell and the substrate removal from the waste water. Polarization curves were used to evaluate power generation (and the maximum production under a specific external load) and the cell voltage trend which is characterized by activation and ohmic losses: 32 mW/ and 41 mW/ are the power density normalized by cathode surface (72 ) reached by respectively first and second cell. The experimental conditions were varied from low to high temperature and from low to high inlet flow rate but the most affecting phenomenon seems to be the biofilm formation since significant voltage drops were noticed after long closed circuit operation. Higher cell voltage characterized the second cell thanks to more active cathode (platinum catalyst used) and more negative bacterial biofilm but a bigger drop in current generation over time affects the system performance and the most reliable reason is the shorter acclimation time compared to the first cell. Cyclic voltammetry tests were carried out on both electrodes to study the potential range of activity and determine an optimal operational voltage despite of mass transport or kinetic limitations. Substrate removal tests at different retention times in power generation conditions (external load 100 Ω) showed a relatively high total nitrogen consumption (maximum 72.2 %) for the first cell while lower values were achieved by the second system meaning that a longer acclimation period is beneficial for nitrifying and denitrifying bacteria to thrive on the cathode biofilm. Effluent pH level are almost similar to the initial values probably because of nitrification and denitrification protons offset.

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36

Pakulytė, Giedrė. "Kuro elementai ir jų panaudojimo galimybės, aprūpinant pastatų kompleksą energija." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060620_215349-85000.

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Human’s energy demand is growing and there is a necessity to solve questions of sustainable energetics, such as security of energy supply, energy efficiency and environment protection. Possible way of the solution of these problems is new and more efficient technologies and new energy sources. Fuel cells are one of the developing and environmentally clean technologies. This master’s report is dealing with cogeneration technologies and only fuel cells are analyzed thoroughly. Most usable type of fuel cells for decentralized power and heat generation is identified and its operating principles and properties are analyzed. Advantages and disadvantages of solid oxide fuel cells are given. Power of the fuel cell is chosen in the particular case, when energy demand of building complex of the hospital is analyzed. The fuel cell is integrated into the energy supply system with other equipment. There are made several alternatives to estimate the operation of the system technologically and economically. The simple pay back period and the net present value are used to estimate economical benefit of the system, when prices of energetic sources and fuel cells are varied. Finally, academic knowledge and calculation results are summarized and conclusions of the final report are given.

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37

Schneider, Kenneth. "Photo-microbial fuel cells." Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.675704.

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Fundamental studies for the improvement of photo-microbial fuel cells (pMFCs) within this work comprised investigations into ceramic electrodes, toxicity of metal-organic frameworks (MOFs) and hot-pressing of air-cathode materials. A novel type of macroporous electrode was fabricated from the conductive ceramic Ti2AlC. Reticulated electrode shapes were achieved by employing the replica ceramic processing method on polyurethane foam templates. Cyclic voltammetry of these ceramics indicated that the application of potentials larger than 0.5 V with regard to a Ag/AgCl reference electrode results in the surface passivation of the electrode. Ti2AlC remained conductive and sensitive to redox processes even after electrochemical maximisation of the surface passivation, which was shown electrochemically and with four terminal sensing. Application of macroporous Ti2AlC ceramic electrodes in pMFCs with green algae and cyanobacteria resulted in higher power densities than achieved with conventional pMFC electrode materials, despite the larger surface area of the Ti2AlC ceramic. The effect of electrode surface roughness and hydrophobicity on pMFC power generation and on cell adhesion was examined using atomic force and confocal microscopy, contact angle measurements and long-term pMFC experiments. The high surface roughness and fractured structure of Ti2AlC ceramic was beneficial for cell adhesion and resulted in higher pMFC power densities than achieved with materials such as reticulated vitrified carbon foam, fluorine doped tin oxide coated glass or indium tin oxide coated plastic. Toxicity of the MOF MIL101 and its amine-modified version MIL-101(Cr)-NH2 on green algae and cyanobacteria was assessed on the basis of both growth in liquid culture and by exclusion zones of agar colonies around MOF pellets. MOF MIL101 was found harmless in concentrations up to 480 mg L-1 and MIL-101(Cr)-NH2 did not exhibit toxic effects at a concentration of 167 mg L-1. Air-cathodes were produced from a range of carbon materials and ion-exchange membranes. Hot-pressing of Zorflex Activated Carbon Cloth FM10 with the proton-selective Nafion® 115 membrane provided the best bonding quality and pMFC performance.

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38

Saxe, Maria. "Bringing fuel cells to reality and reality to fuel cells : A systems perspective on the use of fuel cells." Doctoral thesis, KTH, Energiprocesser, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9192.

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With growing awareness of global warming and fear of political instability caused by oil depletion, the need for a society with a sustainable energy system has been brought to the fore. A promising technology often mentioned as a key component in such a system is the fuel cell technology, i.e. the energy conversion technology in focus in this thesis. The hopes and expectations on fuel cells are high and sometimes unrealistically positive. However, as an emerging technology, much remains to be proven and the proper use of the technology in terms of suitable applications, integration with society and extent of use is still under debate. This thesis is a contribution to the debate, presenting results from two fuel cell demonstration projects, looking into the introduction of fuel cells on the market, discussing the prospects and concerns for the near-term future and commenting on the potential use in a future sustainable energy system. Bringing fuel cells to reality implies finding near-term niche applications and markets where fuel cell systems may be competitive. In a sense fuel cells are already a reality as they have been demonstrated in various applications world-wide. However, in many of the envisioned applications fuel cells are far from being competitive and sometimes also the environmental benefit of using fuel cells in a given application may be questioned. Bringing reality to fuel cells implies emphasising the need for realistic expectations and pointing out that the first markets have to be based on the currently available technology and not the visions of what fuel cells could be in the future. The results from the demonstration projects show that further development and research on especially the durability for fuel cell systems is crucial and a general recommendation is to design the systems for high reliability and durability rather than striving towards higher energy efficiencies. When reliability and durability are achieved fuel cell systems may be introduced in niche markets where the added values presented by the technology compensate for the initial high cost. QC 20100909 Energy Systems Programme Clean Urban Transport for Europe GlashusEtt

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39

MASSI, JUNIOR LUIZ. "Abrigo temporário para desabrigados em situações emergenciais, com suporte de energia elétrica a partir de células a combustível a hidrogênio." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/23513.

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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-03-03T14:44:05Z No. of bitstreams: 0 Made available in DSpace on 2015-03-03T14:44:05Z (GMT). No. of bitstreams: 0 Dissertação (Mestrado em Tecnologia Nuclear) IPEN/D Instituto de Pesquisas Tecnológicas do Estado de São Paulo, São Paulo

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40

Lewis, Spenser M. "Simplified core physics and fuel cycle cost model for preliminary evaluation of LSCR fueling options." Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51772.

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The Liquid Salt Cooled Reactor (LSCR) provides several potential benefits compared to pressurized water-cooled reactor systems. These include low operating pressure of the liquid salt coolant, the high burnup tolerance of the fuel, and the high operating temperatures which leads to increases in efficiency. However, due to inherently low heavy metal loading, the fuel cycle design presents specific challenges. In order to study options for optimizing the fuel design and fuel cycle, SCALE6.1 was used to create simplified models of the reactor and look at various parameters. The primary parameters of interest included packing factor and fuel enrichment. An economic analysis was performed on these results by developing a simple fuel cycle cost (FCC) model that could be used to compare the different options from an economic standpoint. The lithium enrichment of the FLiBe coolant was also investigated. The main focus was to understand the practical limitations associated with the Li-7 enrichment and whether it could be used for beneficial purposes. The main idea was to determine whether a lower-than-equilibrium enrichment could be used at reactor start up so that the Li-6 isotope acts as a burnable absorber. The results for the lithium enrichment study showed that the enrichment converges over time, but the amount of time required to reach steady state is much too long and the FLiBe coolant could not be utilized for reactivity control as a burnable absorber. The results found through this research provide reasonable guidelines for expected costs and narrow down the types of configurations that should be considered as fuel design options for the LSCR. Additionally, knowledge was gained on methods for modeling the system not only accurately but also efficiently to reduce the required computing power and time.

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41

Oedegaard, Anders. "Development and characterisation of a portable direct methanol fuel cell stack." Gerhard-Mercator-Universitaet Duisburg, 2006. http://www.ub.uni-duisburg.de/ETD-db/theses/available/duett-03012006-080812/.

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This thesis deals with the development and characterisation of a portable direct methanol fuel cell stack. In addition, calculations of the transport of methanol and water in the membrane are compared with experimentally determined values. It also includes investigations of the behaviour of single-cells and some of its components, as the anode gas diffusion layer and the anode flow-field. For the addition of methanol to the anode feed loop, a passive concept based on a permeable tube was developed and verified by both experiments and simulations.

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42

Wang, Chao. "A COMPUTATIONAL STUDY OF LINKING SOLID OXIDE FUEL CELL MICROSTRUCTURE PARAMETERS TO CELL PERFORMANCE." Wright State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=wright1377786080.

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43

Wright, Emma Victoria. "Investigation of a novel solid oxide fuel cell interconnect." Thesis, Keele University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265019.

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44

Holtkamp, John Calvin. "New Formic Acid Fuel Cell Orientations to Reduce the Cost of Cell Components." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1257239630.

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45

Still, Michael Joseph. "All-air moisture and energy recovery system for fuel cell exhaust." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17051.

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46

Fedock, John Andrew. "Low temperature polymer electrolyte fuel cell performance degradation." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002565.

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47

Copek, Tomáš. "Ukládání elektrické energie do výhřevných plynů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241877.

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This master’s thesis deals with Power to Gas technology. In this concept electrical energy is used for hydrogen production via electrolysis. Hydrogen can be injected in limited amount into natural gas grid, used for power generation via fuel cells or as a reactant for methanation process. Characteristics of hydrogen and ways of hydrogen production, storage and transport are described. Fuel cells are described as a device which uses hydrogen for power production. Crucial part of this thesis consists of a description of Power to Gas concept and a design of Power to Gas unit with electrical power of 9,5 kW. Three different units were designed for three different times of day operation. Efficiency and economical assessment was carried out for these three Power to Gas units.

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48

Raji, Atanda Kamoru. "Modelling and development of fuel cell off grid power converter system." Thesis, [S.l. : s.n.], 2008. http://dk.cput.ac.za/cgi/viewcontent.cgi?article=1039&context=td_cput.

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49

Balogun, Sunday Julius. "Static Optimization of Fuel Cell Plug-In Hybrid Electric Vehicle." Thesis, Northern Illinois University, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10978070.

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This thesis focuses on the static optimization of a fuel cell plug-in hybrid electric vehicle. The vehicle is been powered by three (3) sources of electrical energy. These sources of electrical energy are: fuel cell, supercapacitor, and lithium-ion battery. The main target of this thesis is to make good the performance of a fuel cell plug-in hybrid electric vehicle. This will be achieved by applying static optimization method on the dynamic equations of a moving hybrid vehicle. The optimization model of this plug-in hybrid electric vehicle (PHEV) was formulated bases on multiple objectives. The objective parameters are: cost, volume, and mass. We were able to apply static optimization algorithm to find optimal solutions for both the objective values and decision variables of the multiple energy sources. The optimization model formulated from the dynamic equations, objective specifications, and design constrains were found to be feasible, bounded, and optimizable by subjecting the primal optimization model to its equivalent dual optimization test. Advanced vehicle simulator (ADVISOR) was used to stimulate vehicle performance of our design on a standard driving cycle. The results provide a better outcome than that of standard driving cycles.

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50

Sanchez, Antonio. "Energy management in electric systems fed by fuel cell stacks." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00590217.

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The growth of distributed energy resources together with the incorporation of new technologies in the generation and storage of energy are imposing new control and operational strategies. Due to its storage capability and that it is considered to be clean energy; fuel cell (FC) is one of the most promissory technologies as a stationary energy source in micro grids and also in transportation applications. Therefore, two main issues are addressed in this work; the conception, design, and setup of a fully instrumented test bench for proton exchange membrane (PEM) FC stacks and the design and experimental test of a new dynamic energy-exchange control strategy for multi source and multi load systems. To define the test bench instrument requirements, in the first part a complete dynamic model review is given. In the next section, relevant information regarding the setup of the FC test bench design and implementation is included, i.e., specification criteria of the instruments and acquisition and data display system. Some experimental results are performed in order to demonstrate the potentialities of the setup. In the following chapter, a new dynamic energy exchange control strategy (DSER) is introduced and tested in a two port system via simulation and experimentation. In order to establish a comparison and integrate the DSER in a FC application, in the fifth chapter a three port system - including a static model of FC - and two different control approaches, are tested via simulation. The thesis is closed with some concluding remarks and some potential research topics generated from this work.

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Tesis sobre el tema "Energia, Fuel cell"

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