779 resultados para Ionic liquid, Lignocellulosics, Sugarcane bagasse, Pretreatment
                                
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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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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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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
                                
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
                                
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
                                
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Pós-graduação em Química - IBILCE
                                
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
                                
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Pós-graduação em Engenharia Mecânica - FEG
                                
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Pós-graduação em Biotecnologia - IQ
                                
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In this research the aim was produce a particleboard with alternative materials and evaluated its physical and mechanical characteristics. The raw materials used are residues from sucarcane bagasse (SC) (Saccharum officinarum) and stem leaves of bamboo (B) (Dendrocalamus giganteus), bonded with a bi component adhesive based on castor oil. It was produced particleboards with five different traces: 100% SC, 75% SC+25% B, 50% SC+50% B, 25% SC +75%B and 100 % B. Their physical and mechanical characteristics were evaluated accordingly to Brazilian standard NBR 14810-3. Regarding the results obtained, it can be detached that for physical and mechanical evaluation it is evident a negative relation among the amount the sugarcane bagasse and their physical and mechanical characteristics, that is particleboards with low concentrations of sugarcane bagasse had better results. However all particleboards could be recommended for use as sealing particleboards in the segment of civil construction.
                                
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The biomass resulting from processing sugarcane bagasse has been considered a source of cellulose with the potential production of bio-fuels. This lignocellulose can be processed into ethanol since is hydrolyzed by chemical processes (acids) or biotechnology (enzymes) which generate sugars suit for fermentation. This study had the objective to utilize physical and chemical pre-treatment processes for prehydrolysis of sugarcane bagasse. The experimental treatment was adjusted at a factor of 4 X 2, by the combination of pre-hydrolysis timing (15, 30, 45 and 60 minutes) and sulfuric acid concentrations (7.0% and 9.0%) which was incubated at a temperature of 121° C in an autoclave. The treatment data was subjected to analysis of the variance and averages which were compared using the Tukey test with a probability of 5%. The results obtained showed that through pretreatment acid applied on the lignocellulose material, there was a significant break from the substrate fibers like cellulose, hemicellulose and lignin.
                                
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Pós-graduação em Biotecnologia - IQ
                                
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Ionic liquids based on 1-alkyl-3-methylimidazolium cations and the hydrogen sulfate (or bisulfate) anion, HSO4-, are much more viscous than ionic liquids with alkyl sulfates, RSO4-. The structural origin of the high viscosity of HSO4- ionic liquids is unraveled from detailed comparison of the anion Raman bands in 1-ethyl-3-methylimidazolium hydrogen sulfate and 1-butyl-3-methylimidazolium hydrogen sulfate with available data for simple HSO(4)(-) salts in crystalline phase, molten phase, and aqueous solution. Two Raman bands at 1046 and 1010 cm(-1) have been assigned as symmetric stretching modes nu(s)(S = O) of HSO4-, the latter being characteristic of chains of hydrogen-bonded anions. The intensity of this component increases in the supercooled liquid phase. For comparison purposes, Raman spectra of 1-ethyl-3-methylimidazolium ethyl sulfate and 1-butyl-3-methylimidazolium methyl sulfate have been also obtained. There is no indication of difference in the strength of hydrogen bond interactions of imidazolium cations with HSO4- or RSO4- anions. Raman spectra at high pressures, up to 2.6 GPa, are also discussed. Raman spectroscopy provides evidence that hydrogen-bonded anions resulting in anion-anion interaction is the reason for the high viscosity of imidazolium ionic liquids with HSO4-. If the ionic liquid is exposed to moisture, these structures are disrupted upon absorption of water from the atmosphere.
 
                    