862 resultados para alternative energy sources


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Since the beginning of life in society, the human being has sought sources of energy that can be used continuously, or stored to be consumed in times of need. The various energy generation processes has enabled the human race for the implementation of many activities ranging from food preparation, handling of large industries and even the possibility of total annihilation by the availability of powerful nuclear weapons. In Brazil, whereupon the various deleterious aspects and especially the finite resources used on a large scale for the energy conservation, there is a huge devotion of society referred to the prospects for alternatives to the use of energy in local, regional and global, but overall, as it wouldn’t be different, the main factors in this scenario are economic. The fact that the unused potential of a region in the use of alternative sources of energy leads to a larger socio-environmental prejudice generalized to all. The purpose of this project is targeted for a comprehensive, systemic and integrated discussion about some of the main alternative energy sources, associated with technical procedures related to them, to contribute to a better and effective use of natural resources available in each region of the country, in order to minimize the impacts on the environment in which they are inserted.

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Faced with the global discussion about the development of new alternative energy sources, this work tries to contribute to the understanding of the introduction of biodiesel in the energy market, identifying the barriers in the social logic, economic and productive in different spaces, rural and urban. Based on the guidelines of the National Biodiesel Production and Use Program (PNPB), it intended to accompany the implementation of public policies in relation to family farmers settled in the Pontal, located in the western region of São Paulo. In parallel, we will analyze the organizational structure and logistics of the production of biodiesel in the city, although it does not dependent on agricultural production and it is not a target of public policies, it takes advantage of the demand created by PNPB when it comes to increasing the amount of biodiesel blended with mineral origin diesel. The activity examined in the urban space is the collection of used frying oil held by Ecosanta Biofuels, a company located in the town of Maua, São Paulo metropolitan region. The monograph aims to broaden our understanding despite the urban-rural issue regarding the obstacles and opportunities in expanding renewable energy

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The substitution of diesel by biodiesel meets the current scenario to increase the consumption of alternative energy sources promoting sustainable development of a country. However, the production of biodiesel concurrently generates the formation of glycerine in the process is a by-product. The main application of glycerine is in the food industry, cosmetics, soaps, pharmaceuticals, among others, but these segments are not capable of absorbing the generated volume of glycerine, whereas the total volume of the biodiesel produced about 10% correspond to glycerine. Glycerine obtained from the transesterification reaction (necessary for production of biodiesel) triglycerides and alcohol contains certain impurities such as water, salts, esters, alcohol, and residual oil, which decrease the value. Thus, the purification process or the direct use of glycerine become essential to make it competitive biodiesel production process. This work aims to evaluate the different processes of purification and the use of glycerine obtained as by-product in the production of biodiesel. The research was theoretical, based on technical articles and theses published on this subject, and from these databases was established a summary of the most important processes

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The renewable energy sources presents an important role on the world's current context, its growing is essentially connected to the environmental issues and the energetic security, guided by the search for alternatives of energy. Among the alternative energy sources, the wind energy shows great importance in the brazilian territory, it has a great potential still unexplored and constant growth in the national electric matrix. The specific factor of generation, the conjuncture and the incentive politics influence on the expansion of wind energy in Brazil. Thus, the brazilian wind sector shows features which can be evaluated enable its developing. Keeping that in mind, the present work aims identify which are the advantages and the difficulties for the expansion of this energy source in the brazilian electric matrix. For that, the work studies the different parameters: features of electric generation of the different energy sources, incentive politics, generation costs, CO2 emission, evolution of wind energy in Brazil, the brazilian wind potential, and the regime of complementarily hydro-wind

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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There is a great global concern about the depletion and the high cost of fossil fuel reserves exploitation, more than ever, it is necessary to make a profound study and take advantage of alternative sources that can be used as energy efficiency with an appropriate pricing and low environmental impact. Brazil, which has highlighted using alternative energy sources as the use of ethanol and, in recent years, has been encouraging the expansion of its energy matrix in which the biodiesel will have a strategic importance within the agrobusiness area. Biodiesel is a fuel that can replace the diesel, which is a petroleum derivative. It is an ester, produced in the transesterification reaction of vegetable oils and animal greases, in an alcohol with an additional catalyst, are converted into fatty acids and result in esters with glycerol as sub products. The objective of this study was to estimate the final energy balance for the process biodiesel production from oil chicken waste. The energy balance estimation was quantified in calorific value according to the energy expenditure by calorimetric bomb method. The relationship between input and output of energy was around 0.97. In a first evaluation, the procedures adopted should be improved enough, so the process can become energetic and economically viable.

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The sugarcane industry has been important in the Brazilian economy since the colonial period. The search for alternative energy sources has gained more prominence, by offering a product generating clean energy. With the opening of the Brazilian economy, the sector has undergone transformations operating in a free market environment requiring greater efficiency and competitiveness of those involved in order to stay in business. This scenario is producer/supplier independent, and social aspects related to their stay in the market. Although its share in sugarcane production is smaller than the plant itself, it is still considerable having reached around 20% to 25% in 2008 by employing labor, also production factors had an important economic impact in the regions where they operate. Therefore, this study aimed to estimate the economic efficiency and production of independent sugarcane producers in the state of Paraná through the DEA model. The Data envelopment analysis (DEA) is a nonparametric technique that, using linear programming constructs production borders from production units that employ similar technological processes to transform inputs into outputs.The results showed that of the total surveyed, 13.56% had maximum efficiency (an efficiency score equal to 1). The average efficiency under variable returns to scale (BCC-DEA) was 0.71024. One can thus conclude that for the majority of the samples collected, it might be better use of available resources to the in order to obtain the economic efficiency of the production process.

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Pós-graduação em Engenharia Elétrica - FEIS

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Com o objetivo de identificar áreas do Estado de Alagoas com boas perspectivas de aproveitamento eólico, comparou-se dados de velocidade e direção do vento observados por torres anemométricas do projeto Atlas Eólico e Disseminação da Tecnologia Eólica no Estado de Alagoas. A série utilizada é de 12/2007 a 11/2008 e o estudo focou três regiões distintas: Litoral, Agreste e Sertão. Os padrões médios com maiores velocidades do vento ocorreram na região do Agreste (7,1 ±1,2 ms-1 mensal), seguido do Sertão (6,8 ±0,9 ms-1 mensal) e Litoral ( 5,3 ±0,8 ms-1 mensal). A regularidade da velocidade e a pouca variabilidade de direção do vento torna Alagoas uma ótima opção para a instalação de aerogeradores.

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In recent years the need for the design of more sustainable processes and the development of alternative reaction routes to reduce the environmental impact of the chemical industry has gained vital importance. Main objectives especially regard the use of renewable raw materials, the exploitation of alternative energy sources, the design of inherently safe processes and of integrated reaction/separation technologies (e.g. microreactors and membranes), the process intensification, the reduction of waste and the development of new catalytic pathways. The present PhD thesis reports results derived during a three years research period at the School of Chemical Sciences of Alma Mater Studiorum-University of Bologna, Dept. of Industrial Chemistry and Materials (now Dept. of Industrial Chemistry “Toso Montanari”), under the supervision of Prof. Fabrizio Cavani (Catalytic Processes Development Group). Three research projects in the field of heterogeneous acid catalysis focused on potential industrial applications were carried out. The main project, regarding the conversion of lignocellulosic materials to produce monosaccharides (important intermediates for production of biofuels and bioplatform molecules) was financed and carried out in collaboration with the Italian oil company eni S.p.A. (Istituto eni Donegani-Research Center for non-Conventional Energies, Novara, Italy) The second and third academic projects dealt with the development of green chemical processes for fine chemicals manufacturing. In particular, (a) the condensation reaction between acetone and ammonia to give triacetoneamine (TAA), and (b) the Friedel-Crafts acylation of phenol with benzoic acid were investigated.

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In this project we developed conductive thermoplastic resins by adding varying amounts of three different carbon fillers: carbon black (CB), synthetic graphite (SG) and multi-walled carbon nanotubes (CNT) to a polypropylene matrix for application as fuel cell bipolar plates. This component of fuel cells provides mechanical support to the stack, circulates the gases that participate in the electrochemical reaction within the fuel cell and allows for removal of the excess heat from the system. The materials fabricated in this work were tested to determine their mechanical and thermal properties. These materials were produced by adding varying amounts of single carbon fillers to a polypropylene matrix (2.5 to 15 wt.% Ketjenblack EC-600 JD carbon black, 10 to 80 wt.% Asbury Carbon's Thermocarb TC-300 synthetic graphite, and 2.5 to 15 wt.% of Hyperion Catalysis International's FIBRILTM multi-walled carbon nanotubes) In addition, composite materials containing combinations of these three fillers were produced. The thermal conductivity results showed an increase in both through-plane and in-plane thermal conductivities, with the largest increase observed for synthetic graphite. The Department of Energy (DOE) had previously set a thermal conductivity goal of 20 W/m·K, which was surpassed by formulations containing 75 wt.% and 80 wt.% SG, yielding in-plane thermal conductivity values of 24.4 W/m·K and 33.6 W/m·K, respectively. In addition, composites containing 2.5 wt.% CB, 65 wt.% SG, and 6 wt.% CNT in PP had an in–plane thermal conductivity of 37 W/m·K. Flexural and tensile tests were conducted. All composite formulations exceeded the flexural strength target of 25 MPa set by DOE. The tensile and flexural modulus of the composites increased with higher concentration of carbon fillers. Carbon black and synthetic graphite caused a decrease in the tensile and flexural strengths of the composites. However, carbon nanotubes increased the composite tensile and flexural strengths. Mathematical models were applied to estimate through-plane and in-plane thermal conductivities of single and multiple filler formulations, and tensile modulus of single-filler formulations. For thermal conductivity, Nielsen's model yielded accurate thermal conductivity values when compared to experimental results obtained through the Flash method. For prediction of tensile modulus Nielsen's model yielded the smallest error between the predicted and experimental values. The second part of this project consisted of the development of a curriculum in Fuel Cell and Hydrogen Technologies to address different educational barriers identified by the Department of Energy. By the creation of new courses and enterprise programs in the areas of fuel cells and the use of hydrogen as an energy carrier, we introduced engineering students to the new technologies, policies and challenges present with this alternative energy. Feedback provided by students participating in these courses and enterprise programs indicate positive acceptance of the different educational tools. Results obtained from a survey applied to students after participating in these courses showed an increase in the knowledge and awareness of energy fundamentals, which indicates the modules developed in this project are effective in introducing students to alternative energy sources.

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The purpose of this paper is to analyze innovations and the innovation system and its dynamics in the ethanol sector in the State of Sao Paulo. More specifically, this paper focuses on the development process in the sector, the public policies taken to promote the sector, and the organizations and key players involved in these policies and their responses to unforeseeable changes in economic, social and technological environments. To this end, this paper takes an historical perspective and reviews data on the cultivation of sugar cane, the production of ethanol, and on sugar cane yields as indicators of the innovations achieved in the sector. The geographical distribution of these indicators is also examined. Next, several cases in Piracicaba and Campinas in the State of Sao Paulo are presented; these give us a more concrete idea of the processes involved in innovation and technology transfer. Based on these observations, the ethanol cluster and the innovation system of the State of Sao Paulo are discussed from the viewpoint of the flowchart approach to industrial cluster policy.

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Green innovation, which enables us to extract energy from food crops, caused a food shortage in 2008. Countries suffering severe damage started to reconsider their agricultural policy with the aim of becoming more autonomous. The food price hike of the time looks like a reversal of the celebrated Singer-Prebisch thesis proposed in the 1950s. This paper examines the consequences of this trend on the comparative advantages and development strategies of developing countries. For that purpose, first, trends and short-run fluctuations in the prices of fuel and bio-energy crops are investigated. It is shown that the price series of fuels and the crops are synchronized only after the fuel extracting technology came into effect. Second, the reversal of the Singer-Prebisch thesis is underpinned by the generic form of an endogenous growth model developed by Rebelo (1991). It is shown that as an economy grows, appreciation of the non-reproducible, such as mineral resources and raw labor, over the reproducible, such as capital goods, is the norm rather than an anomaly. Third, the consequences of the food price hike and underlying capital accumulation on the development strategies of labor-abundant and low-income countries are explored. It is concluded that the impact of the food price hikes on the alteration of a development strategy is only incremental, without reinforcement from raw-labor-saving innovation. A case study of inventions by JUKI Corporation, a world-leader in the sewing machine market exemplifies the fact that, of all the major inventions the company have made, raw-labor-saving inventions have not dominated, although JUKI's machines are sold to one of the most raw-labor-intensive industries.

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Actualmente existe un gran interés por ampliar las fuentes de energías alternativas para aviación y conseguir con ello una reducción de la huella de carbono y de la fuerte dependencia energética de los combustibles fósiles en diferentes países. Por ello, se están llevando a cabo muchos estudios de investigación que tienen por objetivo la conversión de la materia prima vegetal o biomasa en una nueva fuente de energía. Sin embargo, la sustitución exitosa de los combustibles derivados del petróleo por biocombustibles, requiere el cumplimiento de unos requisitos estrictos, y unas propiedades adecuadas. Este proyecto estudia la compatibilidad de materiales con las mezclas de bioqueroseno de coco (CBK20), babasú (BBK20) y palmiste (PBK20), con queroseno comercial Jet A-1 (K-2). Los materiales estudiados son poliméricos, metálicos y composites de aviación que forman parte del sistema combustible del avión. Este estudio pretende demostrar que tanto los materiales utilizados, como los combustibles investigados, son compatibles cuando se encuentran en contacto a cierta temperatura. Para ello, se han comparado sus propiedades siguiendo las normas de referencia establecidas. ABSTRACT Currently there is a strong interest to expand alternative energy sources for aviation and thereby achieve a reduction in carbon footprint and the strong energy dependence on fossil fuels in different countries. It is therefore being carried out many researches based on the conversion of vegetable feedstock in a new energy source. However, a successful replacement of petroleum fuels with biofuels, requires compliance with strict requirements and suitable properties. This project studies the materials compatibility with blends of coconut (CBK20), babassu (BBK20) and palm kernel (PBK20) biokerosene with commercial aviation jet fuel Jet A-1 (K-2). Polymeric and elastomeric materials, metals and aviation composites has been studied as part of the aircraft fuel system. The objective of this study is to demonstrate that both, the tested materials and the fuels investigated, are compatible when they are in contact at a certain temperature. For this reason, materials and kerosene properties have been compared using the standard test methods