958 resultados para Biodiesel, legislação, Brasil


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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In heterogeneous catalysis, numerous elements such as titanium and iron have been studied as nanoscale catalysts, but little is known about the use of niobium in nanocatalysis. The nanostructured particles have intrinsic and different physicochemical characteristics with great potential for use in industrial scale. Brazil having the largest known worldwide niobium reserve has the great challenge of creating pioneering technologies with the metal. Biodiesel is an alternative fuel and renewable substitute for regular diesel. Being biodegradable, non-toxic and have CO2 emissions lower than regular diesel, it contributes to the environment and to the independence from oil. The aim of this work was initially synthesize nanoscale particles of niobium pentoxide (Nanospheres, nanorods, nanofibers, nanocubes) from the sol-gel technique. The characterization of different nanoscale structures obtained was performed using different analytical techniques such as x-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The synthesized nanometer niobium oxide will be used as a heterogeneous catalyst in biodiesel synthesis from commercial soybean oil, checking in detail what the effect of morphology is presented (Nanospheres, nanorods, nanofibers, nanocubes) in the yield of biodiesel synthesis, comparing these results with those already described in literature for the amorphous niobium oxide and other oxide catalysts. The biodiesel obtained was characterized by gas chromatography system equipped with a FID detector

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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 aim of this work was to investigate the effect of different feeding times (2, 4 and 6 h) and applied volumetric organic loads (4.5, 6.0 and 7.5 gCOD L-1 day(-1)) on the performance of an anaerobic sequencing batch biofilm reactor (AnSBBR) treating effluent from biodiesel production. Polyurethane foam cubes were used as inert support in the reactor, and mixing was accomplished by recirculating the liquid phase. The effect of feeding time on reactor performance showed to be more pronounced at higher values of applied volumetric organic loads (AVOLs). Highest organic material removal efficiencies achieved at AVOL of 4.5 gCOD L-1 day(-1) were 87 % at 4-h feeding against 84 % at 2-h and 6-h feeding. At AVOL of 6.0 gCOD L-1 day(-1), highest organic material removal efficiencies achieved with 4-h and 6-h feeding were 84 %, against 71 % at 2-h feeding. At AVOL of 7.5 gCOD L-1 day(-1), organic material removal efficiency achieved with 4-h feeding was 77 %. Hence, longer feeding times favored minimization of total volatile acids concentration during the cycle as well as in the effluent, guaranteeing process stability and safety.

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The research presented in this article aims to identify and to analyze the cases of environmental conflicts in the microrregião de Viçosa, Minas Gerais, Brasil. For this were performed data surveys were conducted in the archives of the Ministério Público regarding the municipalities of microrregião in study and a workshop with various social movements of the mesorregião da Zona da Mata. From this survey on we check the conflict established between environmental legislation and farm workers, and also the concentration of the penalty on small cases of violations of environmental legislation. Thus, we conclude that to think about environmental conflicts is require the recognition of inequalities of power and the different types of knowledge and rationalities involved in the appropriation of natural resources by society.

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Considering agrarian legislation of the last 50 years, this article expressed the objetive to identify and describe the concepts that are used for the characterization and understanding of the conformation of the brazilian agrarian space. We noted, in this context, a process of change in the laws, which suppressed the concepts of latifundio (landlordism) and minifundio (small parcels property), which created concepts of small property, of average property, of productive property and of family agriculture, but which not considered other important definitions: large farms and paternal agriculture. This substitution of interpretative concepts limits the understanding of the brazilian agrarian dynamics, especially if we consider the analysis of contradictory process of development capitalism in the field, in Brazil.

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Los biocombustibles introducen espacios agrícolas en la producción energética. Luego modifican la gobernanza de las redes energéticas y de los territorios productivos. Las principales críticas a los biocombustibles se dirigen a su producción a partir de cultivos tradicionales, pero interesa preguntarse también sobre la sostenibilidad de su producción a partir de cultivos alternativos, que no competirían con los cultivos alimentarios, puesto que se ubicarían en regiones agrícolas marginales. El texto trata sobre las producciones de biocombustibles de los países de América del Sur, en sus contextos internacionales, nacionales y locales. Se profundiza la mirada sobre Argentina, Brasil y Colombia, líderes continentales en el sector. Se analizan la evolución del mercado energético, los actores involucrados y las políticas implementadas. A otra escala, se plantea la puesta en marcha de las cadenas de biocombustibles alternativos.

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The research presented in this article aims to identify and to analyze the cases of environmental conflicts in the microrregião de Viçosa, Minas Gerais, Brasil. For this were performed data surveys were conducted in the archives of the Ministério Público regarding the municipalities of microrregião in study and a workshop with various social movements of the mesorregião da Zona da Mata. From this survey on we check the conflict established between environmental legislation and farm workers, and also the concentration of the penalty on small cases of violations of environmental legislation. Thus, we conclude that to think about environmental conflicts is require the recognition of inequalities of power and the different types of knowledge and rationalities involved in the appropriation of natural resources by society.

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Considering agrarian legislation of the last 50 years, this article expressed the objetive to identify and describe the concepts that are used for the characterization and understanding of the conformation of the brazilian agrarian space. We noted, in this context, a process of change in the laws, which suppressed the concepts of latifundio (landlordism) and minifundio (small parcels property), which created concepts of small property, of average property, of productive property and of family agriculture, but which not considered other important definitions: large farms and paternal agriculture. This substitution of interpretative concepts limits the understanding of the brazilian agrarian dynamics, especially if we consider the analysis of contradictory process of development capitalism in the field, in Brazil.

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Los biocombustibles introducen espacios agrícolas en la producción energética. Luego modifican la gobernanza de las redes energéticas y de los territorios productivos. Las principales críticas a los biocombustibles se dirigen a su producción a partir de cultivos tradicionales, pero interesa preguntarse también sobre la sostenibilidad de su producción a partir de cultivos alternativos, que no competirían con los cultivos alimentarios, puesto que se ubicarían en regiones agrícolas marginales. El texto trata sobre las producciones de biocombustibles de los países de América del Sur, en sus contextos internacionales, nacionales y locales. Se profundiza la mirada sobre Argentina, Brasil y Colombia, líderes continentales en el sector. Se analizan la evolución del mercado energético, los actores involucrados y las políticas implementadas. A otra escala, se plantea la puesta en marcha de las cadenas de biocombustibles alternativos.

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Considering agrarian legislation of the last 50 years, this article expressed the objetive to identify and describe the concepts that are used for the characterization and understanding of the conformation of the brazilian agrarian space. We noted, in this context, a process of change in the laws, which suppressed the concepts of latifundio (landlordism) and minifundio (small parcels property), which created concepts of small property, of average property, of productive property and of family agriculture, but which not considered other important definitions: large farms and paternal agriculture. This substitution of interpretative concepts limits the understanding of the brazilian agrarian dynamics, especially if we consider the analysis of contradictory process of development capitalism in the field, in Brazil.

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Resumo:

The research presented in this article aims to identify and to analyze the cases of environmental conflicts in the microrregião de Viçosa, Minas Gerais, Brasil. For this were performed data surveys were conducted in the archives of the Ministério Público regarding the municipalities of microrregião in study and a workshop with various social movements of the mesorregião da Zona da Mata. From this survey on we check the conflict established between environmental legislation and farm workers, and also the concentration of the penalty on small cases of violations of environmental legislation. Thus, we conclude that to think about environmental conflicts is require the recognition of inequalities of power and the different types of knowledge and rationalities involved in the appropriation of natural resources by society.