261 resultados para Casca de arroz carbonizada
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The waste, exaggerated and incorrect disposal of biomass are common practices in modern times where everything is disposable. However the growing concern with the nature and the environment compel man to give nobler destinations for these products through sustainability and recycling of waste. Banana peel is a residual biomass, which is not consumed. It generates tons of waste per week in São Paulo city. This trash is disposed in dumps and landfills, which could be reduced by using it as reinforcement in natural composites. The high density polyethylene (HDPE) is a polymer derived from the ethylene polymerization and is easily recycled. Which makes it a sustainable material. In the present work characteristics of the natural composite composed with banana peel and high-density polyethylene were studied. It was noted that removing the lignin present in the banana peel, the fiber introduces a significant improvement in thermal resistance. The preparation of composite was made with a ratio of 5% and 10% of reinforcement in comparison with polymeric matrix mass. Composites were thermally, mechanically and microscopically characterized. The addition of fiber in the polymer increased the mechanical strength of the composite. The fiber surface treatment with distilled water removed the amorphous material present in the fibers, improving significantly thermal stability and increasing crystallinity of the celullose. The addition of 5% fiber in mass to the polymer increased significantly the tensile strength and elasticity modulus for the composite. With 10% of fiber addiction there were also an improvement when compared with pure HDPE, but when compared with 5% composite the mechanical properties are slightly lower. This may be due to the fiber particle size, which are small and eventually become a hub of tension ... (Complete abstract click electronic access below)
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Isolate microorganisms that fermenting xylose to ethanol is a challenge to expand production of biofuels from lignocellulosic materials. For this work was tested fermentation of xylose by yeast strains isolated from grape skins (Vitis spp) in order to ethanol produce. The yeasts were grown in submerged fermentation with xylose as a carbohydrate source. Aliquots were taken every 24 hours to measure cell growth, sugar consumption and ethanol production. The yeast had an production ethanol average of 2.5 g / L and yield (Ye / s) 0.12 g / g, showing that they have the ability to produce ethanol from xylose.
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Pós-graduação em Ciência Florestal - FCA
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Pós-graduação em Agronomia (Agricultura) - FCA
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Pós-graduação em Agronomia - FEIS
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Pós-graduação em Agronomia (Energia na Agricultura) - FCA
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Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE
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The global energy scenario is currently a widely discussed topic, with growing concern about the future supplies. Thus, much attention has been dedicated to the utilization of biomass as an energy resource. In this respect, orange peel has become a material of great interest, especially to Brazil, which generates around 9.5 million tons of this waste per year. To this end, the authors studied the kinetics of the thermal processing of dried orange peel in inert and oxidizing atmosphere. The thermodynamic parameters were determined by the Ozawa-Flynn-Wall method for the global process observed during heating from the 25 degrees C up to 800 degrees C. The thermal analysis in air and nitrogen showed 3-2 stages of mass loss, respectively, with approximately 20% residual mass under a nitrogen atmosphere. The increase in the values of activation energy for the conversion points between 20% and 60% for thermal effects in air and nitrogen atmosphere was observed. The activation energy obtained in an oxidizing atmosphere was higher than that obtained under a nitrogen atmosphere. The fourier-transform infrared spectroscopy and X-ray diffraction analysis showed that the material has a high level of complexity with the presence of alkali and alkaline earth groups as well as phosphate, plus substances such as pectin, cellulose and lignin.
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Coffee husk is an abundant by-product generated by the coffee industry and it can be used for the production of-value-added phenolic compounds. Currently, this residue has no commercial use due to the presence of anti-nutritional compounds and it is returned to the soil or burned. The aim of this study was to evaluate the content of phenolic compounds in Robusta coffee husk, the adequacy of this residue as substrate for fermentation processes, as well as evaluating the influence of fungal solid state fermentation to obtain phenolic compounds from this residue. In the present study, the use of different solvents for the extraction of polyphenols was evaluated and the content was found to be in the range of 96.9-159.5 mg of galic acid (GA).g(-1) substrate, depending on the solvent used. The best solvent was acetone, therefore it was selected for extraction. Studies were carried out to evaluate the effect of solid-state fermentation in the release of phenolic compounds, using the filamentous fungi Penicillium purpurogenum. The total phenolic content increased from 159.5 up to 243.2 mg GA.g(-1) substrate as a result the solid-state fermentation.
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Pós-graduação em Agronomia - FEIS
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Agronomia - FEIS
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Pós-graduação em Agronomia (Energia na Agricultura) - FCA
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)