Made available in DSpace on 2017-07-21T14:32:38Z (GMT). No. of bitstreams: 1 Tammy Sales Rosa.pdf: 1898317 bytes, checksum: 62f560bd48bfd3197dcc87a1edba0877 (MD5) Previous issue date: 2016-09-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Must of the energy consumption in the world comes from non-renewable sources of energy, the main information occurs in nature in a longer time than their consumption and subject of depletion causing negative impacts in its use. Alternative sources are necessary. The use of biomass as fuel material, is widely used and appears as the main substitute for fossil fuels. The purpose of this work is to evaluate the energy potential of macrófitas Eichhornia crassipes (water hyacinth) and Pistia stratiotes (water lettuce) existing in the region of Campos Gerais, Ponta Grossa, Paraná, Brasil. Assessment took place gravimetric design,analysis growth, immediate analysis and determination of the calorific value. The macrophyte water hyacinth and water lettuce showed intermediate energy potential compared biomasses studied today. Immediate analysis did not show satisfactory values when compared to biomass already used. For higher calorific values the average and the productivity of the dry mass values were similar to biomasses already used. The water hyacinth showed characteristic values about water lettuce. / Grande parte do consumo energético do mundo é proveniente de fontes não renováveis de energia, ou seja, sua formação na natureza ocorre em um tempo maior do que o seu consumo, sendo passíveis de esgotamento e causando impactos negativos na sua utilização. Fontes alternativas se fazem necessárias. O uso de biomassa como material combustível é muito utilizado e aparece como principal substituto dos combustíveis fósseis. Portanto este trabalho teve como objetivo, avaliar potencial energético das macrófitas Eichhornia crassipes (aguapé) e Pistia stratiotes (alface d’água) existentes na região dos Campos Gerais, município de Ponta Grossa, Paraná, Brasil. Para avaliação realizou-se dimensionamento gravimétrico, análise de crescimento, análise imediata e determinação do poder calorífico. As macrófitas aguapé ealface d’água apresentaram potencial energético intermediário quando comparadas as biomassas hoje estudadas. A análise imediata apresentou valores não satisfatórios quando comparados a biomassa já utilizada. Para o poder calorífico superior os valores foram médios e para a produtividade da massa seca os valores foram semelhantes às biomassas já utilizadas.O aguapé mostrou valores característicos superiores a alface d’água.

O gerenciamento de resíduos sólidos urbanos (RSU) tornou-se uma tarefa que demanda ações diferenciadas e articuladas, em função da quantidade e diversidade dos mesmos. O grande desafio está em encontrar soluções ambientalmente seguras, socialmente adequadas e economicamente eficientes para equacionar este problema. Todavia, se corretamente gerenciados, estes resíduos podem ser aproveitados do ponto de vista energético. Estimativas realizadas neste estudo apontam para um potencial de geração de energia a partir de resíduos urbanos, para o Brasil, da ordem de 16 GW (utilizando o processo de incineração) ou 5,8 GW (pela digestão anaeróbia em aterros). Outros benefícios da recuperação energética dos resíduos também podem ser destacados tais como: (a) benefícios estratégicos, uma vez que essa ação pode contribuir como fonte alternativa de energia; (b) benefícios ambientais, pois colabora com organização dos aterros e a mitigação de gases de efeito estufa; (c) benefícios sócio-econômicos, devido ao desenvolvimento de tecnologia nacional com o uso de equipamento e insumos nacionais e, sobretudo, (d) emprego de mão-de-obra qualificada e não qualificada nas várias etapas do processo de recuperação energética. O presente trabalho faz uma análise das tecnologias potencialmente aplicáveis no Brasil, para recuperação energética a partir RSU, e propõe uma série de diretrizes para esse aproveitamento, levando em consideração as especificidades da realidade brasileira. / The management of solid waste (MSW) has become a challenge that demands articulated and non-conventional actions because of the quantity and diversity of such wastes. Finding environmentally friendly, socially adequate and economically efficient solutions to overcome this issue is the challenge to be faced. Nevertheless, if properly managed, these wastes can be recovered from the standpoint of energy. Estimates presented in this work highlight a potential power generation from urban waste, in Brazil, around 16 GW (using incineration process) or 5.8 GW (by anaerobic digestion in landfills). Several other advantages of recovering energy from waste could also be rolled as follows: (a) strategic benefits, since it may contribute as an alternative energy source and increase energy supply; (b) environmental benefits, once it contributes to improve waste management and to the mitigation of greenhouse gases; (c) social-economic benefits, due to the development of a Brazilian technology taking advantage of national equipment and materials, and most important, (d) employment of skilled and unskilled labor in the various stages of the energy recovery process. This thesis analyzes though the technologies potentially applicable in Brazil for energy recovery from MSW, and proposes guidelines for such use taking into account the specificities of the Brazilian reality.

O sistema energético pode ser visto não apenas como uma restrição, mas também como uma oportunidade para o desenvolvimento produtivo de uma sociedade. Pela segunda ótica, o objetivo principal a ser perseguido é a da garantia do suprimento energético e da adequação das formas e fontes de energia aos usos finais demandados. Ao mesmo tempo, dentro do contexto global de preocupação com as mudanças climáticas, faz-se necessário conceber uma nova trajetória de desenvolvimento para o estado de São Paulo, mais moderna, com maior participação de fontes renováveis de energia, focada na diminuição da ntensidade energética, e mais voltada ao desenvolvimento tecnológico. Este trabalho procurou, então, mostrar que o estado de São Paulo já promoveu uma verdadeira transformação de sua matriz energética em termos da participação de energias renováveis, no entanto, que os paulistas ainda devem encarar outros desafios maiores como saber lidar com a tendência não declinante de sua intensidade energética nos últimos anos. Enfim, ao decompor o indicador de intensidade energética para o estado de São Paulo, buscou-se explicitar as possíveis causas de forma a observar se há um tradeoff aparente entre o uso de fontes energéticas renováveis e a estagnação dos valores da intensidade energética estadual. / The energy system can be understood not only as a constraint, but also as an opportunity for a society productive development. Taking the second approach, the main objective to be pursued is that of securing energy supply and adequacy of forms and sources of energy to the demanded end uses. At the same time, within the context of global concern about climate change, it is necessary to devise a new development path for the state of São Paulo, more modern, with a higher share of renewable energy sources, focused on reduction of energy intensity and more focused on technological development. This study sought to show, therefore, that the state of São Paulo has promoted a true transformation of its energy matrix in terms of the share of renewable energies. However, the state must still face other major challenges such as how to deal with its non-downward energy intensity trend in recent years. Finally, by decomposing the energy intensity indicator for the state of São Paulo, we sought to clarify the possible causes in order to observe whether there is an apparent tradeoff between the use of renewable energy sources and the stagnation of the state energy intensity values.

O motor a álcool pré-vaporizado tem potencial para ser uma alternativa mais eficiente e menos poluente aos motores a álcool convencionais. Nele, o combustível é vaporizado com calor rejeitado pelo próprio motor e admitido na fase gasosa, aproveitando-se das vantagens dos motores com combustíveis nessa fase sem alguns dos seus inconvenientes. O projeto foi aperfeiçoado buscando viabilidade técnica e econômica para sua instalação em veículos automotores. Água do sistema de arrefecimento cede calor para a ebulição do combustível. As novas tecnologias para injeção de combustíveis gasosos contribuem para esse objetivo, bem como o desenvolvimento de um sistema sustentável e auto-ajustável de geração de vapor de etanol que usa a água do sistema de arrefecimento. Conseguiu-se maior eficiência em quase todos os regimes de funcionamento estudados, bem como meios de reduzir as principais emissões automotivas indesejáveis. / Pre-vaporized ethanol engine (PVEE) has potential to be more efficient and less pollutant than conventional ethanol-powered engines. In it, fuel is vaporized with heat rejected by engine itself and intook in gaseous form, taking advantage of this kind of fuel but without some of its inconveniences. The PVEE project was polished looking for economical and technical liability to future use in automotive vehicles. New gaseous fuel injection technologies contribute to this goal, together the development of a sustainable and self-adjustable ethanol vapor generating system who uses water from engine\'s cooling systems. Better efficiency was achieved in almost all investigated regimes, as well as were found ways to reduce the main undesirable automotive emissions.

Global warming and the energy crisis are two of the greatest challenges on which mankind is currently focused. This has forced governments and other organisations to think how to protect the environment and how to reduce fuel costs. A variety of new and exciting technologies are being investigated to address the energy problem. Alternative energy sources such as solar power, fuel cells, wind power and tidal waves are active areas of commercial and scientific pursuit. A major area of current research is moving towards the hydrogen economy and hydrogen based energy systems. Hydrogen can be produced in many ways, most commonly by steam reforming of hydrocarbon (70% to 85% thermal efficiency) but the downside is that it releases carbon mono oxide (CO)), compared with commercial PEM electrolysers where performance has been reported to be 56 -73% at normal temperature pressure(NTP) with zero carbon emission. Electrochemical production of hydrogen has several advantages: (i) It gives pure hydrogen. (ii) It allows portability (e.g. Solar energy could be used to power the electrochemical cell). (iii) It can be produced on demand. The generation of Hydrogen via electrolysis has been the subject of many studies over the last two hundred years. However, there is still room for further work to improve both the efficiency of the process and methods of storage of the gas. The cleanest method at present is to produce hydrogen by electrolysis, and the main focus of this research is to design and develop such a green energy fuel cell for on-demand application. The aim of the work presented in this thesis was to further investigate the electrolysis method for hydrogen production. An Electrochemical fuel cell contains a minimum of two electrodes: the positively charged electrode called the anode where oxygen bubble will form, and the second negatively charged electrode called the cathode, where hydrogen bubbles will form during a chemical reaction caused by applying electrical current between these electrode. The project was initiated with the objective of finding a low cost solution for on-demand hydrogen generation. To establish a starting point, the first cell (cell-1) design was based on the work of Stephen Barrie Chambers (see chapter 3) to check the performance levels. The fabrication of the cell-1 design resulted in a mixture of hydrogen and oxygen in the same chamber, which means the cell-1 design, has a possible fire and explosion hazard. The device also has the drawback of lower performance of hydrogen production; columbic efficiency is between 40% to 46% at 1 amp to 3 amp current in 30% KOH alkaline solution. However, the advantage of reproducing Stephen’s innovation is that it allowed a quick and deep understanding of hydrogen generation. This thesis presents recent work on the fabrication of low cost electrolysis cells containing continuous flow alkaline (KOH, up to 30%) electrolyte using low cost electrodes (stainless steel 316) and membranes based on ultrahigh molecular weight polyethylene (UHMW PE) to produce hydrogen without the hazard of fire and explosion. In this research an On-Demand Hydrogen Generation cell-3 achieved a 95% hydrogen generation coulombic efficiency, which is about 49% efficiency improvement as compared to the stainless steel electrode, and was 22% better than the nano structured electrode. The typical cell voltage is 2.5 V at current flow ranging from 30 to 120 mA cm-2 in 30% KOH electrolyte. The achievement here of such high efficiencies paves the way for more research in the areas of space management, electrode surface structure and flow control (based on the application requirement). This invention can be used for aeronautic, marine and automotive application as well as in many other areas.

Transmission charges are levied against generators and suppliers for their use of transmission networks. The majority of existing transmission charging methods were designed for a system dominated by conventional and controllable generation. The resultant transmission charges reflect network users’ contribution to the system peak. The integration of renewable generation brings fundamental challenges in transmission planning and charging. Main criteria of transmission planning have changed from meeting system peak demand to the trade-offs between operational and investment costs. Transmission charging is required to effectively reflect these trade-offs. This research work aims to develop novel transmission charging methods for low carbon power systems, reflecting the contribution to transmission investments from different generation technologies, different locations, and critically different times. It firstly identifies the key drivers and key conditions of transmission investments under the economic criteria. In the second step, the key drivers and conditions are reflected in the developing of T-LRIC method, ToU-LRIC method and ToU-ICRP method. Major innovations of the proposed methods include 1. reflecting the trade-offs between operational and investments costs by employing investment time horizons to reflect the impacts of system operation on transmission investments (T-LRIC method and ToU-LRIC method). 2. differentiating various generation technologies by firstly quantifying their impacts on the time horizons of network investments, then translating these impacts to transmission charges (T-LRIC method and ToU-LRIC method). 3. providing time-specific transmission charges, in which Time-of-Use periods are identified by clustering time-series congestion costs or transmission charges, thus reflecting the typical conditions of system congestions and the required transmission investments (ToU-LRIC method and ToU-ICRP method). The main benefits from introducing these innovations are i) to guide the short-run behaviours of network users, thus mitigating transmission congestions and promoting efficient utilization of existing networks; ii) to incentivize appropriate generation expansion, thus reducing or deferring costly future transmission investments.

This research focuses on studying the feasibility of placing large wind turbines on deep-ocean platforms. Water tank studies have been conducted using the facilities at Alden Research Laboratories (ARL) on 100:1 scale Tension Leg Platform (TLP) and Spar Buoy (SB) models. Froude scaling was used for modeling the offshore wind turbine designs. Primary components of the platform turbine, tower, and cable attachments were fabricated in ABS plastic using rapid prototyping. A wireless data acquisition system was installed to prevent umbilical data cables from affecting the behavior of the platform when exposed to wave loading. In Phase I testing, Froude-scaled TLP and Spar Buoy models at a 100:1 scale were placed in a water flume and exposed to periodic waves at amplitudes ranging from 0.5 cm - 7.5 cm and frequencies ranging from 0.25 Hz - 1.5 Hz. The testing was conducted on simple tower and turbine models that only accounted for turbine weight at the nacelle. In Phase II testing, emphasis was placed on further testing of the tension leg platform as a more viable design for floating offshore wind turbines. The tension leg platform scale model was improved by adding a disc to simulate drag force incident at the top of the tower, as well as a rotor and blades to simulate the gyroscopic force due to turbine blade rotation at the top of the tower. Periodic wave motions of known amplitude and frequency were imposed on the model to study pitch, heave, roll, surge, sway motions and mooring cable tensions (in Phase II only) using accelerometers, inclinometers, capacitance wave gage, and load cells. Signal analysis and filtering techniques were used to refine the obtained data, and a Fourier analysis was conducted to study the dominant frequencies. Finally, Response Amplitude Operators (RAO's) were plotted for each data set to standardize the results and study the overall trend with respect to changes in wave amplitude and frequency. For Phase I testing, it is shown that surge motion of the platform dominates other motions for both the tension leg platform and spar buoy, and varying tether pretension has little effect on response amplitude operator values. For phase II testing, it was found that the introduction of thrust and gyroscopic forces increases sway and pitch motions as well as upstream tether forces. Coupling effects of pitch motion with roll and sway due to the presence of gyroscopic forces were also seen. The present experimental results can be used to validate the hydrodynamic kernels of linear frequency-domain models, time-domain dynamics models, and computational simulations on floating wind turbines. Numerical analysis and simulations have been conducted in a separate study at WPI. These simulations are comparable to the experimental results.

Orientador: Helenice de Oliveira Florentino Silva / Resumo: A escassez de combustíveis fósseis e a demanda por fontes alternativas de energia renovável e limpa são impulsionadores para o desenvolvimento de biocombustíveis, tais como o biohidrogênio. Este gás é conhecido por seu alto valor calorífico, extrema leveza e baixa densidade, além de, ao ser queimado, produzir apenas vapor d'água e calor. Dentre os modos de produção, destaca-se a fermentação escura, a qual gera biohidrogênio e subprodutos através do tratamento microbiológico de resíduos agroindustriais. O objetivo deste trabalho foi modelar matematicamente este bioprocesso, estudar suas propriedades à luz da teoria de estabilidade, além de propor um modelo de otimização que determine uma combinação das concentrações de substrato e bactérias, tais que maximizem o rendimento da produção de biohidrogênio. Foram propostas duas heurísticas para a resolução do modelo, Algoritmo de Busca em Vizinhança Variável e Algoritmo Memético. Os resultados das simulações numéricas mostraram que o modelo obtido corrobora com a dinâmica bioquímica e microbiológica do bioprocesso. / Abstract: The lack of fossil fuels and the demand of alternative, renewable and clean energy sources promote development in biofuels, as biohydrogen. It is known by its high heat, extreme lightness and low density and also when it burns, the products are only steam and energy. Among the productions ways, we highlight dark fermentation, which generates biohydrogen and subproducts through organic waste microbiological treatment. The aim of this work was to mathematical model this bioprocess, to study its properties via stability analysis, besides to propose a optmization model to determine a combination of substract and bacteria concentrations, in order to maximize biohydrogen production yield. To solve the mathematical model have been proposed two heuristics: Variable Neighboor Search Algorithm and Memetic Algorithm. Numeric simulations showed that the mathematical model corroborates with the bioprocess microbial and biochemical dynamics. / Mestre

The benefits of the Oceans and Seas have been exploited by societies for many centuries; the marine offshore and naval sectors have been the predominant users of the waters. It has been overlooked until recently, that significant amounts of energy can be harnessed by waves, providing an additional abundant resource for renewable energy generation. The increasing energy needs of current societies have led to the consideration of waves as an exploitable renewable resource. During the past decades, advancements have been made towards commercialising wave energy converters (WECs), though significant knowledge gap exists on the accurate estimation of the potential energy that can be harnessed. In order, to enhance our understanding of opportunities within wave energy highly resolved long-term resource assessment of potential sites are necessary, which will allow for not only a detailed energy estimation methodology but also information on extreme waves that are expected to affect the survivability and reliability of future wave energy converters. This research work aims to contribute the necessary knowledge to the estimation of wave energy resources from both highly energetic and milder sea environment, exhibiting the opportunities that lay within these environments. A numerical model SWAN (Simulating WAves Nearshore), based on spectral wave formulation has been utilised for wave hindcasting which was driven by high resolution temporal and spatially varying wind data. The capabilities of the model, allow a detailed representation of several coastal areas, which are not usually accurately resolved by larger ocean models. The outcome of this research provides long-term data and characterisation of the wave environment and its extremes for the Scottish region. Moreover, investigation on the applicability of wave energy in the Mediterranean Sea, an area which was often overlooked, showed that wave energy is more versatile than expected. The outcomes provide robust estimations of extreme wave values for coastal waters, alongside valuable information about the usage of numerical modelling and WECs to establish energy pattern production. Several key tuning factors and inputs such as boundary wind conditions and computational domain parameters are tested. This was done in a systematic way in order to establish a customized solution and detect parameters that may hinder the process and lead to erroneous results. The uncertainty of power production by WECs is reduced by the introduction of utilization rates based on the long-term data, which include annual and seasonal variability. This will assist to minimize assumptions for energy estimates and financial returns in business plans. Finally, the importance of continuous improvements in resource assessment is stressed in order to enhance our understanding of the wave environment.

Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Includes bibliographical references (leaf 112). / The opportunities for utilizing Jamaica/s rich supply of renewable energy resources as a base for stead, environmentally sound rural development is tremendous. This thesis explores as way of tapping this potential. Jamaica's current plans for both energy and rural community development are reviewed and general suggestions offered as to how the necessary integration of the two plans can be achieved for short and long term energy conscious planning and program implementation. The focus of the proposal is on the development of Rural Community Development Centers that would be designed to build a renewable energy infrastructural base for the specific communities and generally respond to the energy, educational and productive needs as they change over time. / by Michael Onaje Jackson. / M.Arch.