716 resultados para Combustíveis


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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A produção de alumina pelo processo Bayer produz de 1 a 3 toneladas de resíduo por tonelada de alumínio. Esse resíduo é denominado lama vermelha, composto de minerais não solúveis em hidróxido de sódio concentrado, como hematita e outros óxidos férreos, quartzo e óxidos de titânio. A lama vermelha possui em sua composição variados teores de NaOH, dependendo especificamente da planta industrial utilizada. A proposta desse trabalho é avaliar o processo de absorção de gases provenientes de uma caldeira em contracorrente com uma suspensão de lama vermelha a 27%, em torre spray e em torre de recheio estruturado. Foram realizados experimentos variando-se o tipo de torre de absorção, temperatura da fase líquida e teor de sólidos na fase líquida para avaliar a redução do teor dos gases de combustão na saída da torre de absorção e a variação do pH de acordo com o tempo de operação, para que fosse possível identificar o tempo necessário para que ocorra a neutralização da lama vermelha, bem como a redução no teor de dióxido de carbono, para isso foram realizadas medições dos teores de gases na entrada e na saída da torre de recheio estruturado, bem como medições de temperatura e pH. A absorção de CO2 presente no gás de combustão pela suspensão de lama vermelha se dá pelo processo da carbonatação, no qual o gás reage com o NaOH presente na lama vermelha, sendo a água o catalisador. Os resultados obtidos após os experimentos foram satisfatórios, e concluiu-se que o processo realizado nas torres de absorção é eficiente para a diminuição do pH da lama vermelha e a redução do teor de CO2 liberado para a atmosfera, promovendo um ganho duplo para o meio ambiente.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The contamination of underground waters is a subject of great importance, since a lot of people use this kind of source for public supply. This paperwork manages with how gas stations can contaminate these waters and what are some remediation techniques, used nowadays to solve this problem. The contamination caused by the gas stations can have its origin in the underground storage tanks when they suffer corrosion and show leaking problems. It’s a topic of great relevance, because the hydrocarbons derivated from petroleum present in the fuels can stay for a long time in the environment. Besides that, an analyses of the risk of contamination by gas stations in the city of Rio Claro was made based on three parameters: density of the gas stations, depth of the underground water and hydraulic conductivity. To achieve such goal, maps were elaborated considering those parameters individually and considering the three of them together. Analyzing those maps, it was concluded see that the spots that represent the biggest risks of contamination in Rio Claro are located southeast and center-west.

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A great competition between companies happens nowadays, due to, among other factors, the globalized economic system, the growing consumer demand and the technological advances. This fact implies the need for fast and efficient tools in decision making. A validated simulation model is able to perform this task. Thus, it was parameterized a simulation model of a fuel distribution terminal. It is a complex system because of its great variability. The model´s data input were collected, however the model was not statistically validated, in other word, does not adequately represent the real system. A search was made for the possible causes of this fact: dividing the compartments of tanker trucks, data collection may have been insufficient, inefficient model for unloading of biofuels

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The market segment of fuel distribution composes an important role in the development of Brazil’s industry and economy. However, it is a sector with intense competitiveness, especially in relation to ethanol. The search for competitive advantage and greater strength to the business are, therefore, of high relevance in this context, in which the concepts of Business Process Management has become more visible. Process Mapping, one of these concepts, has proven “TO BE”a strategic tool for companies which believe in flattening the structure and in the potential benefits that the improvement of its processes can provide. Thus, this work aims to map the process of Ethanol Origination of a company engaged in the distribution of this and other fuel products, and other niche markets. It was understood and designed the macro-process aforementioned and identified failures in subprocess related to it. After applying the method to select priority problems, using risk assessment criteria, five subprocess were identified to receive special action, which consisted in seeking improvements with those involved in the process, in representing its current and ideal models and in defining each department’s responsibilities for the activities in the subprocess proposed form. Thus, it is expected to mitigate mainly two negative effects found in the business: employee’s work overload and company's financial exposure

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Leaking of hydrocarbon in fuel underground storage tanks constitute object of concern for urban environmental management, because therefore they provoke damages to the physical, biological and socioeconomic environment. Though laws that regulate this essential activity exist, aiming at to prevent contamination with hydrocarbon, we observe that this still happens. This fact evidences that the selection of places for installation of gas stations has not considered the characteristics of the natural environment, implying in more critical consequences associated to the leaking. The objective of this work is to elaborate a chart applied to the gas stations in Rio Claro/SP. The determination of the Index of Environmental Sensitivity for elaboration of such chart was carried through breaking the selection of factors of Environmental Sensitivity of physical, biological and socioeconomic environment. The balance of these factors was given by means of Ad hoc consultation. The crossing of the information was carried through using the method of overlapping of overlays. The result is a chart that shows us areas with classes of high, middle and low Environmental Sensitivity. One gives credit that this type of material can be used as criterion in the selection of adjusted areas for installations of new gas stations and management of the already installed gas stations. The diagnosis of the current situation of the gas stations in the area and recommendations had also been elaborated.

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Métodos comparativos foram desenvolvidos para detectar e quantificar o corante solvente azul 14 (SA-14) em amostras de combustíveis. O método eletroanalítico foi baseado na técnica de voltametria de onda quadrada (VOQ) com detecção em +0,60 V vs. Ag/AgCl sobre o eletrodo de carbono vítreo, usando tampão Britton-Robinson e N, N-dimetilformamida (1:1, v/v) como eletrólito suporte. Para metodologia, envolvendo a cromatografia líquida de alta performance (CLAE) foi empregada uma fase móvel composta de acetonitrila e cloreto de lítio (85:15, v/v) e a detecção eletroquímica foi realizada em um potencial de oxidação em +0,65 V vs. Ag/AgCl. Sob as melhores condições de trabalho curvas de calibração foram obtidas, para ambos os métodos, as quais foram lineares na faixa de concentração de 5,0×10 -7 a 6,0×10 -6 mol L-1 (VOQ) e 8,0×10 -8 a 3,0×10 -6 mol L-1 (CLAE). Os métodos foram aplicados para quantificar o corante em amostras de álcool e querosene após um simples processo de extração em fase sólida com resultados de recuperação satisfatórios.

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The contamination of the physical environment occurs as a result of the lack of planning and inadequate management of hazardous products. Due to the difficulty of the characterization and study of soil and groundwater, the contamination has been long neglected. The characterization of these areas by research techniques through direct methods such as physical and chemical analysis, are widely used in the diagnosis and monitoring. However, despite presenting quantitative results, this method is not representative in spatial terms. The purpose of this work is to bring geophysical complementation with the diagnosis, bringing the spatial element for the detection of the contamination plume. In the study area, there was a railway accident in 1999 in which three wagons fell and spilled 240,000 L of diesel onto the soil. The main objective is to assess the presence of contaminants in the residual phase and dissolved in the subsurface, using the technique of Electrical Tomography (ETR), understand the effects of natural attenuation process in the degradation of hydrocarbons and changes in electrical properties in soil and groundwater. The results allowed the definition of three distinct patterns of resistivity region with presence of dissolved phase, set in a historical chemical analyzes: low values (> 60Ω.m) associated with the presence of hydrocarbons in an advanced stage of degradation, intermediate values (260Ω.me 511Ω .m) indicative of coexistence of residual hydrocarbons and dissolved phase, and high values (> 1000Ω.m), which reveal the prevalence of residual phase with incipient degradation, possibly in high toxicity concentrations for effective action of biodegradation processes. The diagnostic of areas with potential accumulation of residual phase can subsidize the planning of remediation techniques and promote the complete decontamination of the area

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)