Orientador: Antonio José de Almeida Meirelles / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T17:38:53Z (GMT). No. of bitstreams: 1 Bessa_LarissaCastelloBrancoAlmeida_M.pdf: 3274287 bytes, checksum: 0f57997f7783168db1f2649fc09da7f0 (MD5) Previous issue date: 2012 / Resumo: Apesar da sua alta demanda energética, a destilação é uma das técnicas de separação de misturas líquidas mais amplamente utilizada no mundo. Com o intuito de melhorar a eficiência térmica deste processo, possibilidades de integração térmica e alternativas para a redução do consumo energético de colunas de destilação constituem sempre um tópico de intensa investigação. Dentre as técnicas de integração térmica, podem-se citar as diferentes possibilidades de se empregar colunas de múltiplo efeito e o uso de bomba de calor. Desta forma, este trabalho visou estudar dois modelos propostos de integração térmica de colunas de destilação para produção de etanol, considerando uma grande quantidade de compostos minoritários a fim de representar as condições reais encontradas em destilarias industriais. As configurações propostas foram analisadas via simulação computacional utilizando-se o software comercial Aspen Plus, da Aspen Technology, Inc., e foram comparadas do ponto de vista de seu desempenho energético, recuperação de etanol e qualidade do produto. O processo foi otimizado utilizando-se planejamento experimental fatorial, associado à análise de superfícies de respostas. Como etapa preliminar deste trabalho, os resultados obtidos do simulador para as configurações atuais de colunas de destilação foram comparados com dados industriais, através da análise por cromatografia gasosa de amostras coletadas em plantas industriais em operação. Apesar de apresentar alguns desvios significativos, de modo geral o simulador comercial conseguiu reproduzir de forma satisfatória o processo de destilação alcoólica industrial. Os dois modelos de integração térmica estudados apresentaram bons resultados, com consumo específico de vapor de 0,995 e 1,431 kg vapor/L álcool hidratado (significando redução de 54 e 33 % no consumo) no processo em duplo efeito tradicional e adaptado, respectivamente. Apesar de apresentar menor redução de consumo energético, na integração em duplo efeito adaptado a diferença de temperatura entre o topo da coluna A e a base da coluna B1 é de 14,3 ºC, exigindo um trocador de calor com menores dimensões que no caso do duplo efeito tradicional, no qual esta diferença é de apenas 5 ºC. Ainda, o vácuo necessário na integração tradicional é maior que na configuração adaptada, o que exige colunas com maiores diâmetros. Por fim, observou-se que os componentes minoritários, em especial os álcoois superiores, exerceram uma grande influência no consumo de vapor do processo / Abstract: Despite its high energetic demand, distillation is one of the most widely used techniques for separating liquid mixtures in the world. In order to improve the energetic efficiency of this process, possibilities of thermal integration and alternatives for reducing the energy consumption of distillation columns are always a topic of intense investigation. Among the techniques of thermal integration, there are different possibilities of employing the multiple effect columns and the use of heat pump. Thus, this work aimed to study two proposed models for thermal integration of distillation columns to produce ethanol, considering a large amount of minor compounds in order to represent the actual conditions found in the industrial mills. Those proposed configurations were analyzed through computer simulation using the commercial software Aspen Plus, from Aspen Technology, Inc., and they were compared regarding their energetic performance, ethanol recovery and final product quality. The process was optimized using experimental factorial design and surface response analysis. As a preliminary step of this work, the results of the simulator for the current distillation columns configurations were compared with industrial data through analysis by gas chromatography of samples collected from mills in operation. Although it has presented some significant deviations, in general the simulator was able to reproduce satisfactorily the industrial process of alcoholic distillation. Both thermally integrated configurations showed good results, with a specific steam consumption of 0.995 and 1.433 kg steam/L hydrated alcohol (reduction in the consumption of 54 and 33 %) in the traditional and adapted double effect process, respectively. Despite the lower reduction in energy consumption, the process in double effect adapted has presented a temperature difference between the top of column A and the bottom of column B1 of 14.3 ºC, requiring a smaller heat exchanger than in the case of traditional double effect process, in which this difference is only 5 ºC. In addition, the necessary vacuum in the traditional double effect process is greater than in the adapted configuration, which requires columns with larger diameters. Finally, it was observed that minor compounds, in special the high alcohols, had a great influence in the steam consumption of the process / Mestrado / Engenharia de Alimentos / Mestre em Engenharia de Alimentos

abstract: The transport of hydrogen to the Earth’s deep interior remains uncertain. The upper mantle minerals have very low hydrogen solubilities (hundreds of ppm). The hydrogen storage capability in the transition zone minerals (2 wt%) is high compared to those of the upper mantle. The hydrogen storage in the lower mantle is not well known. The main minerals in the lower mantle bridgmanite and ferropericlase have very low hydrogen storage capacities (less than 20 ppm). In order to further understand the hydrogen storage in the lower mantle, a series of experiments had been conducted to simulate the environment similar to the Earth’s mantle. The experiments with hydrous Mg2SiO4 ringwoodite (Rw) show that it converts to crystalline dense hydrous silica, stishovite (Stv) or CaCl2-type SiO2(mStv), containing ∼1 wt% H2O together with bridgmanite (Brd) and MgO at the pressure-temperature conditions expected for lower mantle depths between approximately 660 to 1600 km. Brd would break down partially to dense hydrous silica (6–25 mol%) and(Mg,Fe)O in mid-mantle regions with 0.05–0.27 wt% H2O. The hydrous stishovite has a CaCl2 structure, which is common among hydrous minerals in the lower mantle. Based on this observation, I hypothesize the existence of hydrous phases in the lower mantle. The experiments found a new hexagonal iron hydroxide (η-Fe12O18+x/2Hx) between the stability fields of the epsilon and pyrite-type FeOOH at 60–80 GPa and high temperature. The new phase contains less H2O, limiting the H2O transport from the shallow to the deep mantle in the Fe–O–H system. Possible hydrogen storage in Ca-perovskite was studied. CaPv could contain 0.5–1 wt% water and the water in CaPv could distort the crystal structure of CaPv from cubic to tetragonal structure. In conclusion, hydrogen can be stored in hydrous stishovite in the shallower depth of the lower mantle. At greater depth, the new η phase and pyrite-type phase would take over the hydrogen storage. The role of CaPv in deep water storage needs to be considered in future studies. / Dissertation/Thesis / Doctoral Dissertation Natural Science 2019

<p> Phase equilibrium relations were determined in the system NaAlSiO8-NaAlSiO4-H2O on a P-T projection in the P-T range 0.5-10Kb and 150°-900°C, and on three isobaric (2Kb, 5.15Kb and 7. 32Kb) T-X projections. The T-X stability field of analcite determined in this study has a relatively large distorted pentagonal shape. The petrogenetic problem of analcite is fully discussed. On the composition join NaAlSiO4-H2O, the phase relation is not binary for the transition: nepheline hydrate I = nepheline + H2O; there exists a narrow three-phase zone for the transition. The true P-T curve was determined in terms of a ternary univariant reaction: nepheline hydrate I+ analcite = nepheline + H2O. Another univariant reaction (zeolite species P. = analcite + nepheline hydrate I+ H2O) was found at 2Kb/215°C and 5.15Kb/235°C and determined on a P-T projection. In the system NaAlSi3O8-SiO2-H2O, albite contains a maximum of about 5 Wt.% silica in solid solution at 5.15Kb/670°C.</p> <p> The equilibrium compositions of various univariant phases were determined essentially by phase boundary-location on several isobaric T-X projections. Three singular points were determined: two of them are approximately located at 0.8Kb/390°C and 9.4Kb/475°C on a univariant curve (N-h I+ Anl =Ne+ H2O). The other one is approximately located at 6Kb/655°C on the (Ab) univariant curve.</p> </p> A simple method for determining H2O-solubility in melts was developed and applied to the study of the system NaAlSi3O8-NaAlSiO4-H2O. Using this method, solubility data are simply obtained as by-products of the experimental runs made for the investigation of the phase equilibria. The amount of water required to make an H2O-saturated melt (from the total amount of water in the original charge) is taken as the dissolved water in the melt; the solubility value is corrected by determining the amount of moisture originally absorbed in the starting powder. The method is generally applicable to the determination of H2O-content in any hydrous phase. The H2O-solubility in a melt is not too sensitive to a variation in anhydrous composition of the melt (~ 6±1 Wt.% H2O at 2Kb and ~11±1 Wt.% H2O at ~5Kb in the range of compositions Ab100Ne0-An40Ne60). H2O-solubility in the (Anl) and (Ne) univariant melts was determined up to l0Kb (H2O contents: 4.7 Wt.%/1.1Kb and 850°C, 6.2 Wt. %/2Kb and 804°C, 10.8 Wt. %/5.2Kb and 672°C, l2.2 Wt.% /6.6Kb and 655°C, 13.2 Wt. %/7.3Kb and 652°C and 14(?) Wt.% /10Kb and 632°C ). The origin of water bubbles in quenched hydrous glasses is essentially attributed to the exsolution of the dissolved water in melts upon quenching.</p> <p> The sequence of P-T curves around a quaternary invariant point (~5Kb and ~635°C) in the system NaAlSiO4-KAlSiO4-SiO2-H2O was theoretically discussed. The most probable four P-T diagram types are proposed, one of which is expected to be the real one.</p> <p> Phase relations in the system NaAlSi3O3-NaAlSiO4-H2O are theoretically discussed up to ~15Kb. The discussion is largely based on the equilibrium compositions of invariant phases approximately estimated from data presented in Parts 1 and 2. Six invariant points are examined. Two of them, I5 and I6, have been predicted to occur; I5 is inferred to be located at ~13Kb/~500°C where five phases Jd, N-h I, Anl, Ne and V coexist, and I6 to be located at ~0.5Kb/-375°C where Ab, Ne, Anl, N-h I and V coexist. The phase relations around the other four are partly modified. The maximum P-T stability field of analcite is deduced. The stability field of solidus analcite is extremely large whereas that of liquidus analcite is very much limited. The maximum stability field of liquidus analcite is a small triangular area defined by three invariant points I1 (5.15Kb/657°C), I2 (11Kb/650°C) and I4 (12.5Kb/575°C).</p> / Thesis / Doctor of Philosophy (PhD)

The dramatic change in properties of water near its critical point (i.e. T = 374 °C and p = 22.1 MPa, note: 100 MPa = 0.1 GPa = 1 kbar ≈ 1000 atm) has been a subject of numerous studies and also lead to the development of various applications (e.g. in waste destruction, biomass processing, and the synthesis of advanced ceramic materials). However, comparatively little is known about the behavior of water at gigapascal pressures. The present study attempts to explore catalytical properties and reactivity of extreme water with respect to several oxide systems: SiO2, TiO2 and LiAlSiO4. “Extreme water” here is defined as existing at p,T conditions of 0.25–10 GPa and 200–1000 °C, thus considering both supercritical fluid and hot compressed ice. The study shows that extreme water can make high pressure mineral phases accessible at relatively mild T conditions. At the same time, high pressure aqueous environments appear efficient in stabilizing novel metastable structures and may be considered as a general route for synthesizing new materials. The hydrothermal treatment of SiO2 glass at 10 GPa and 300–550 °C yielded an unusual ultrahydrous form of stishovite with up to 3% of structural water. At the same time, the extreme water environment enhanced notably the kinetics of stishovite formation, making it accessible at unprecedentedly low temperatures. Thus, for the SiO2–H2O system water acts as both catalyst and reactant. For TiO2 a hydrothermal high pressure treatment proved to be of high importance for overcoming the kinetical hindrance of the rutile – TiO2-II transformation. 6 GPa and 650 °C were established as the mildest conditions for synthesizing pure TiO2-II phase in less than two hours. The crystallization of LiAlSiO4 glass in an extreme water environment yielded a number of different phases. In the low pressure region (0.25 – 2 GPa) mainly a zeolite (Li-ABW) and a dense anhydrous aluminosilicate (α-eucryptite) were obtained. At pressures above 5 GPa the formation of novel pyroxene-like structures with crystallographic amounts of structural water was observed. The overall conclusion of this study is that extreme water environments show a great potential for catalyzing phase transitions in oxide systems and for stabilizing novel structures via structural water incorporation. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p>

Midlatitudinal hydrated sulfates on Mars may influence brine pH, atmospheric humidity, and collectively water activity. These factors affect the habitability of the planetary subsurface and the preservation of relict biomolecules. Regolith at grain sizes smaller than gravel, constituting the bulk of the Martian subsurface at regional scales, may be a primary repository of chemical alteration, mechanical alteration, and biosignatures. The Mars Odyssey Gamma Ray Spectrometer with hundreds of kilometers of lateral resolution and compositional sensitivity to decimeter depth provides unique insight into this component of the regolith, which we call soil. Advancing the globally compelling association between H2O and S established by our previous work, we characterize latitudinal variations in the association between H and S, as well as in the hydration state of soil. Represented by H2O:S molar ratios, the hydration state of candidate sulfates increases with latitude in the northern hemisphere. In contrast, hydration states generally decrease with latitude in the south. Furthermore, we observe that H2O concentration may affect the degree of sulfate hydration more than S concentration. Limited H2O availability in soil-atmosphere exchange and in subsurface recharge could explain such control exerted by H2O on salt hydration. Differences in soil thickness, ground ice table depths, atmospheric circulation, and insolation may contribute to hemispheric differences in the progression of hydration with latitude. Our observations support chemical association of H2O with S in the southern hemisphere as suggested by Karunatillake et al. (2014), including the possibility of Fe sulfates as a key mineral group.

Na busca por soluções que minimizem os impactos ambientais, causados especialmente por atividades da economia que dependem integralmente de alguma fonte de energia para funcionar, surgem novas alternativas de caráter renovável. No caso do setor de transportes, que se destaca na emissão de gases efeito estufa, o etanol hidratado proveniente da cana de açúcar tem se mostrado como uma opção à gasolina. Entretanto, para torná-lo competitivo no mercado, o etanol deve ser viável em termos econômicos e energéticos em todas as etapas da cadeia de suprimento. Na distribuição do etanol hidratado no mercado nacional, há uma importante restrição na regulamentação do setor, que determina que o etanol produzido nas usinas tenha passar por bases de distribuição antes de chegar aos centros de consumo, impedindo a entrega direta do mesmo. Assim, a presente pesquisa teve como objetivo investigar os ganhos econômicos e energéticos da distribuição direta do etanol hidratado no estado de São Paulo. Para isso foram criados dois cenários de avaliação, o primeiro, representando o sistema atual de distribuição e o segundo representando a entrega direta. Na avaliação dos cenários foi desenvolvido um modelo custo e outro de gasto energético. A partir dos cálculos realizados, obteve-se um custo de R$ 559,09 mi para o Cenário 1, e de R$ 295,62 mi para o Cenário 2, o que resultou em um ganho de R$ 263,46 mi a partir da entrega direta. Apesar do ganho, sabe-se que a viabilização da entrega direta depende da implementação de novas estruturas, o que implicaria em novos custos. Neste caso o ganho real estaria no custo de transportes, que representa cerca de R$ 137,33 mi. Com relação ao gasto energético, o Cenário 1 resultou em 1,69 bi de MJ, e o Cenário 2 em 1,22 bi de MJ, representando um ganho de 469,4 mi de MJ. Comparando este ganho com outros valores divulgados na literatura para a mesma etapa da cadeia, observa-se que há grande divergência entre os mesmos. Outro aspecto observado foi a pouca representatividade do gasto energético da etapa de distribuição, quando comparada com a etapa agrícola. / In the search for solutions that minimize environmental impacts, especially caused by economic activities that are completely dependent on any source of energy to operate, new alternatives of renewable character emerge. In the case of the transport sector, which stands in the greenhouse gases emissions, the hydrous ethanol from sugar cane has been shown to be an option to gasoline. However to make it competitive in the market, it should be feasible in economic and energetic terms in all steps of the supply chain. In the scenario of distribution of hydrous ethanol in the domestic market, there is an important legal restriction on the regulation of the sector, which states define that ethanol produced in plants must go through distribution bases before coming to consumption centers , preventing the direct delivery. The present study aimed to investigate the economic and energetic gains of direct distribution of hydrous ethanol in the state of São Paulo. For this evaluation two scenarios were created, them first, representing the current distribution system, and the second, representing the direct delivery. To evaluate both scenarios, a cost and an energy consumption models were developed. From the calculations performed, it was obtained a cost of R$ 559,09 million to Scenario 1, and R$ 295,62 million to Scenario 2, which resulted in a gain of R$ 263,46 million from direct delivery. Despite the gain, it is known that the feasibility of direct delivery depends on the implementation of new structures which would imply on new costs. In this case the real gain would be at the cost of transport, which accounts for approximately R$ 137,33 million. With respect to energy consumption, the Scenario 1 resulted in 1,69 billion of MJ, and Scenario 2 in 1,22 billion of MJ, which represents a gain of 469.4 million of MJ . Comparing this gain with other values reported in the literature for the same step of the supply chain, it is observed that there is a great difference between them. Another significant aspect is the low representativeness of the energy consumption of the distribution step, when compared with the agricultural step.

Na busca por soluções que minimizem os impactos ambientais, causados especialmente por atividades da economia que dependem integralmente de alguma fonte de energia para funcionar, surgem novas alternativas de caráter renovável. No caso do setor de transportes, que se destaca na emissão de gases efeito estufa, o etanol hidratado proveniente da cana de açúcar tem se mostrado como uma opção à gasolina. Entretanto, para torná-lo competitivo no mercado, o etanol deve ser viável em termos econômicos e energéticos em todas as etapas da cadeia de suprimento. Na distribuição do etanol hidratado no mercado nacional, há uma importante restrição na regulamentação do setor, que determina que o etanol produzido nas usinas tenha passar por bases de distribuição antes de chegar aos centros de consumo, impedindo a entrega direta do mesmo. Assim, a presente pesquisa teve como objetivo investigar os ganhos econômicos e energéticos da distribuição direta do etanol hidratado no estado de São Paulo. Para isso foram criados dois cenários de avaliação, o primeiro, representando o sistema atual de distribuição e o segundo representando a entrega direta. Na avaliação dos cenários foi desenvolvido um modelo custo e outro de gasto energético. A partir dos cálculos realizados, obteve-se um custo de R$ 559,09 mi para o Cenário 1, e de R$ 295,62 mi para o Cenário 2, o que resultou em um ganho de R$ 263,46 mi a partir da entrega direta. Apesar do ganho, sabe-se que a viabilização da entrega direta depende da implementação de novas estruturas, o que implicaria em novos custos. Neste caso o ganho real estaria no custo de transportes, que representa cerca de R$ 137,33 mi. Com relação ao gasto energético, o Cenário 1 resultou em 1,69 bi de MJ, e o Cenário 2 em 1,22 bi de MJ, representando um ganho de 469,4 mi de MJ. Comparando este ganho com outros valores divulgados na literatura para a mesma etapa da cadeia, observa-se que há grande divergência entre os mesmos. Outro aspecto observado foi a pouca representatividade do gasto energético da etapa de distribuição, quando comparada com a etapa agrícola. / In the search for solutions that minimize environmental impacts, especially caused by economic activities that are completely dependent on any source of energy to operate, new alternatives of renewable character emerge. In the case of the transport sector, which stands in the greenhouse gases emissions, the hydrous ethanol from sugar cane has been shown to be an option to gasoline. However to make it competitive in the market, it should be feasible in economic and energetic terms in all steps of the supply chain. In the scenario of distribution of hydrous ethanol in the domestic market, there is an important legal restriction on the regulation of the sector, which states define that ethanol produced in plants must go through distribution bases before coming to consumption centers , preventing the direct delivery. The present study aimed to investigate the economic and energetic gains of direct distribution of hydrous ethanol in the state of São Paulo. For this evaluation two scenarios were created, them first, representing the current distribution system, and the second, representing the direct delivery. To evaluate both scenarios, a cost and an energy consumption models were developed. From the calculations performed, it was obtained a cost of R$ 559,09 million to Scenario 1, and R$ 295,62 million to Scenario 2, which resulted in a gain of R$ 263,46 million from direct delivery. Despite the gain, it is known that the feasibility of direct delivery depends on the implementation of new structures which would imply on new costs. In this case the real gain would be at the cost of transport, which accounts for approximately R$ 137,33 million. With respect to energy consumption, the Scenario 1 resulted in 1,69 billion of MJ, and Scenario 2 in 1,22 billion of MJ, which represents a gain of 469.4 million of MJ . Comparing this gain with other values reported in the literature for the same step of the supply chain, it is observed that there is a great difference between them. Another significant aspect is the low representativeness of the energy consumption of the distribution step, when compared with the agricultural step.

Com o objetivo de gerar um material mais homogêneo quanto à forma e tamanho das partículas formadas (nanopartículas), o presente trabalho visa o estudo das variáveis de preparação do Nb2O5.nH2O via microemulsão inversa (ME). Por meio de um planejamento fatorial completo, estudou-se a influência da concentração do agente precursor, da ordem de adição das microemulsões e da razão água/surfatante (W) no tamanho das partículas formadas. Para análise comparativa, Nb2O5.nH2O também foi preparado pelos métodos da precipitação convencional (PC) e da precipitação em solução homogênea (PSH). Os materiais preparados foram caracterizados por difratometria de raios X (DRX), termogravimetria (TG), microscopia eletrônica de varredura (MEV) e de transmissão (MET), espectrômetria de energia dispersiva (EDS), espectroscopia de absorção no infravermelho por transformada de Fourier (FTIR) e análise de área superficial específica pelo método B.E.T. A adsorção de íons fosfato em Nb2O5.nH2O foi estudada. A melhor forma de preparação do Nb2O5.nH2O via ME foi a utilizada no experimento 2. As micrografias MEV confirmam que os materiais preparados pelo método ME possuem partículas esféricas menores que as dos materiais preparados pelos métodos PC e PSH. Dos modelos cinéticos estudados, o que melhor se ajustou aos dados experimentais de adsorção de íons fosfato nos materiais preparados foi o de pseudo 2a ordem. A quantidade de íons fosfato adsorvida aumenta com a redução do pH da solução inicial. O modelo de isoterma de Langmuir simulou adequadamente os resultados de equilíbrio obtidos, sendo observada a seguinte ordem de capacidade de adsorção: ME2>PSHu>PC>PSHc. A adsorção de íons fosfato em Nb2O5.nH2O é espontânea e endotérmica. Os íons fosfatos podem ser dessorvidos da superfície do Nb2O5.nH2O através do ajuste do pH da solução. A adsorção de íons fosfato em óxido de nióbio hidratado envolve mecanismos de quimissorção, fisissorção e troca iônica. / In the present study the parameters of Nb2O5.nH2O precipitation via reverse microemulsion were investigated with the objective to synthesize homogeneous nanoparticles according to morphology, structure and size. Basic synthesis parameters, such as addition order of microemulsions (O), ratio of water to surfactant (W), ratio of NbOF5-2 to water, were determined by design of experiments. The Nb2O5.nH2O was also prepared by co-precipitation and homogeneous solution method. The materials were characterized by X-ray diffraction (XRD), thermal analysis (TG/DTG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and BET specific surface area measurements. The phosphate adsorption onto Nb2O5.nH2O was performed. The best way to prepared Nb2O5.nH2O via reverse microemulsion was used in experiment 2. MEV micrographs confirmed that materials prepared by microemulsion were smallest than materials prepared by co-precipitation and homogeneous solution. The kinetic data corresponded very well to the pseudo-second-order equation. The phosphate adsorption tended to increase with a decrease of pH. The data fitted well to the Langmuir model and the adsorption capacity for the Nb2O5.nH2O presented the following decreasing order: ME2>PSHu>PC>PSHc. The thermodynamic parameters evaluated reveal the spontaneous and endothermic nature of phosphate adsorption onto Nb2O5.nH2O. Phosphate can be desorbed from the surface of hydrous niobium oxide by adjusting the pH values of the solution. The phosphate adsorption occurs by the mechanisms of chemisorptions, physisorptions and ion-exchange.

Made available in DSpace on 2017-07-10T15:14:36Z (GMT). No. of bitstreams: 1 _kenia_G_Santos.pdf: 1228191 bytes, checksum: c9c0f5b98cfa5d23ac78b799e2ea76c1 (MD5) Previous issue date: 2016-02-12 / Fundação Araucária / The stability of a fuel is critical to providing better engine performance. The biodiesel derived from babassu stands out in relation to this feature. Thus, we sought in this study comparing the effects of the mixture of hydrated ethanol and absolute ethanol with biodiesel in variable proportions of 10, 20 and 30% ethanol (absolute and hydrated) by volume performance in the motor generator diesel cycle direct injection and on some physical and chemical characteristics. Among these, they analyzed properties such as viscosity and density, which are characteristics that influence the spark. And beyond these, the calorific value of the mixtures was also determined. Subsequently, biodiesel blends/hydrous ethanol and biodiesel/anhydrous ethanol to concentrations of 10%, 20%, 30%, 100% biodiesel babassu oil and diesel fuel were tested in diesel cycle engine, which evaluated the consumption of fuels (mL), volumetric consumption, generated load and energy efficiency with variations of resistive loads of 1.5, 3 and 4.5 kW. The physicochemical properties of biodiesel contribute to the assessment of the established parameters for better quality biodiesel. And the viscosity and density analysis is influential on the combustion of mixtures in the engine. The high calorific value (PCS) for all treatments with the use of each, it follows that the PCS no influence on consumption. The variation of the resistive load caused a change in motor behavior and motor generator system as a whole. The highest efficiency obtained for mixtures was resulting in effective charge of 4.5 kW for mixtures of B80E20 (hydrated ethanol: 12% less efficient than biodiesel) and B80E20 (absolute ethanol: 10% less efficient than biodiesel). The application of ethanol with an additive to biodiesel helps reduce the use of fossil fuels. / A estabilidade de um combustível é fundamental para proporcionar melhor desempenho do motor. O biodiesel proveniente oriundo do babaçu destaca-se em relação a essa característica. Com isso, buscou-se neste trabalho avaliar comparativamente os efeitos da mistura do etanol hidratado e etanol absoluto com biodiesel em proporções variadas de 10, 20 e 30% de etanol (absoluto e hidratado), em volume, no desempenho no motor gerador ciclo diesel de injeção direta e sobre algumas características físico-químicas. Dentre estas, analisaram-se propriedades como a viscosidade e densidade que são características que influenciam na ignição. E além destas, o poder calorífico das misturas também foi determinado. Posteriormente, as misturas de biodiesel/etanol hidratado e biodiesel/etanol absoluto com concentrações de 10%, 20% e 30%, biodiesel 100% de babaçu e diesel foram testados no motor de ciclo Diesel, em que foram avaliados o consumo dos combustíveis (mL), consumo volumétrico, carga gerada e eficiência energética com variações de cargas resistivas de 1,5, 3 e 4,5 kW. As propriedades físico-químicas do biodiesel contribuem para a avaliação dos parâmetros estabelecidos para melhor qualidade do biodiesel. E as análises de viscosidade e densidade são influenciadoras na combustão das misturas no motor. O poder calorífico superior (PCS) para todos os tratamentos com o consumo de cada um, conclui-se que o PCS não influenciou no consumo. A variação da carga resistiva causou uma mudança no comportamento do motor e do sistema motor gerador como um todo. A maior eficiência obtida para as misturas foi resultante na carga efetiva de 4,5 kW para as misturas de B80EH20 (12% menos eficiente que o biodiesel) e B80EA20 (10% menos eficiente que o biodiesel). A aplicação do etanol com um aditivo ao biodiesel favorece a redução do uso de combustíveis fósseis

As atuais condições ambientais tem direcionado o foco de muitas pesquisas para o reaproveitamento de resíduos agroindustriais na obtenção de novos materiais. Entre estes resíduos, destacam-se as fibras naturais, como o bagaço de cana-de-açúcar, principalmente por apresentarem características importantes para as aplicações industriais: de origem renovável, biodegradável e de baixo custo. A celulose extraída de fibras vegetais revela-se como uma alternativa promissora para a produção de materiais híbridos orgânico-inorgânicos com propriedades multifuncionais e amplas aplicações. Este trabalho busca primeiramente à obtenção de híbridos celulose/óxido de alumínio hidratado a partir do tratamento e modificação da celulose extraída do bagaço de cana-de-açúcar e sua posterior aplicação na produção de membranas. As fibras de celulose foram tratadas com clorito de sódio em meio ácido e com a mistura de ácidos nítrico e acético, com objetivo de verificar a influência do tratamento químico da celulose nas propriedades térmicas dos híbridos formados. O Al2O3.nH2O foi preparado pelo método da precipitação convencional partindo-se do alumínio metálico. As celuloses tratadas e o Al2O3.nH2O foram caracterizados por DRX, FTIR, TG, DSC e MEV. O tratamento químico das fibras de celulose não interferiu na estabilidade térmica e no processo de combustão das celuloses. Os híbridos foram produzidos nas proporções de 5, 10, 15 e 20% de óxido hidratado e caracterizados por DRX, TG, DSC, Calorimetria de Combustão e MEV/EDS. Os resultados obtidos mostraram uma boa interação entre as fibras de celulose e o óxido de alumínio hidratado. As análises de calorimetria de combustão e de DSC em ar sintético permitiram observar que o Al2O3.nH2O agiu como um agente retardante de chamas. A proporção definida para a produção de membranas foi 95Cel/05Al2O3.nH2O. Membranas de celuloses puras e dos híbridos 95CelA/05Al2O3.nH2O e 95CelB/05Al2O3.nH2O foram produzidas nos sistemas solventes de NaOH/ureia e NaOH/tioureia e caracterizadas por DRX, TG, DSC e MEV/EDS. A dissolução das fibras de celulose nos sistemas solventes promoveram a conversão da celulose tipo I (nativa) em celulose tipo II (regenerada). As membranas preparadas com os híbridos 95CelA/05Al2O3.nH2O e 95CelB/05Al2O3.nH2O em NaOH/ureia e 95CelA/05Al2O3.nH2O em NaOH/tioureia apresentaram maior estabilidade térmica e resistência à combustão que as membranas de celulose. / The current environmental conditions has directed the focus of much research for the reuse of industrial residues in obtaining new materials. Among these residues, there are the natural fibers such as sugarcane bagasse, mainly because of the important features for industrial applications: source renewable, biodegradable and low cost. Cellulose extracted from plant fibers revealed as a promising alternative for the production of organic-inorganic hybrid materials with multifunctional properties and broad applications. This paper seeks primarily to obtain hybrids cellulose/hydrous aluminum oxide from the treatment and modification of cellulose extracted from crushed sugarcane and its subsequent application in the production of membranes. Cellulose fibers were treated with sodium chlorite in acid and a mixture of nitric and acetic acids, in order to verify the influence of the chemical treatment of cellulose in the thermal properties of hybrids formed. The Al2O3.nH2O was prepared by the conventional precipitation method starting from metallic aluminum. The treated pulps and Al2O3.nH2O were characterized by XRD, FTIR, TG, DSC and SEM. The chemical treatment of cellulose fibers did not affect the thermal stability of the combustion process celluloses. Hybrids were produced in proportions of 5, 10, 15 and 20% hydrated oxide and characterized by XRD, TG, DSC Calorimetry Combustion and SEM / EDS. The results showed a good interaction between the cellulose fibers and hydrated aluminum oxide. Analyses of combustion calorimetry and DSC in synthetic air propose that the Al2O3.nH2O acted as a flame retardant agent. The set ratio for the production of membranes was 95Cel/05Al2O3.nH2O. Pure cellulose membranes and hybrid 95CelA/05Al2O3.nH2O 95CelB/05Al2O3.nH2O and solvent systems were produced in NaOH/urea and NaOH/thiourea and characterized by XRD, TG, DSC and SEM/EDS. The dissolution of cellulose fibers in solvent systems promoted conversion of cellulose I type (native) type II cellulose (regenerated).The membranes prepared from the hybrids 95CelA/05Al2O3.nH2O and 95CelB/05Al2O3.nH2O in NaOH/urea 95CelA/05Al2O3.nH2O in NaOH/thiourea showed higher thermal stability and resistance to combustion the membranes.