Made available in DSpace on 2014-06-11T19:28:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-25Bitstream added on 2014-06-13T18:57:48Z : No. of bitstreams: 1 santos_lo_me_jabo.pdf: 780193 bytes, checksum: cc0c763c9b87f0bcd74b72f3de8c1fe3 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Este trabalho objetivou testar o uso de tratamento químico combinado ou não com tratamento hidrotérmico, na conservação e qualidade pós-colheita de mangas ‘Tommy Atkins’ e ‘Palmer’, bem como avaliar o efeito da modificação da atmosfera de armazenamento por filmes plásticos e cera de carnaúba no prolongamento da vida útil pós-colheita de mangas ‘Palmer’. Utilizou-se mangas provenientes de pomar comercial de Taquaritinga-SP, safra 2006/2007, que foram colhidas no estádio de maturação “de vez” e imediatamente transportados para o laboratório de Tecnologia dos Produtos Agrícolas da FCAV, Jaboticabal, onde foram selecionadas, visando padronizá-las quanto a coloração, tamanho e ausência de injúrias. Na primeira fase os frutos foram submetidos a tratamento com os fungicidas Sporekill® (cloreto de dodecil dimetil amônio a 12%) e Magnate 500 EC® (imazalil a 50%), associados ou não com tratamento hidrotérmico a 53°C/5 min (‘Tommy Atkins’) e 53°C/10 min (‘Palmer’). Após secagem, eles foram armazenados sob condição de ambiente (23°C, 65% UR), e eram analisados a cada três (‘Palmer’) ou quatro dias (‘Tommy Atkins’), quanto a ocorrência de podridões, aparência, perda de massa e firmeza, assim como quanto ao pH e teores de sólidos solúveis, acidez titulável e ácido ascórbico da polpa. Na segunda fase, o melhor tratamento para a manga ‘Palmer’ foi combinado com diferentes proteções e armazenamento sob condição ambiente (23°C, 65% UR) ou refrigerada (12°C, 65% UR). Os frutos armazenados sob refrigeração, após 28 dias foram levados ao ambiente, para avaliação da evolução do amadurecimento, aos 3 e 6 dias. Utilizou-se os seguintes tratamentos: Testemunha (sem tratamento); Testemunha com tratamento fitossanitário; Filme de polietileno de baixa densidade (PEBD), com espessura de 0,050mm; Polifilme multicamada;... / This work was undertaken to test the use of chemical control in combination or not with hydrothermal treatment on the preservation and post harvest quality of ‘Tommy Atkins’ and ‘Palmer’ mangoes. Also, we evaluated the effect of modifying the storage atmosphere by the use of plastic film and carnauba wax on the shelf life of ‘Palmer’ fruits. Mangoes from a commercial orchard in Taquaritinga-SP were harvested in the season 2006/2007 at the breaker ripening stage, immediately transported to the laboratory of Technology of Agricultural Products, FCAV, Jaboticabal, and selected by color, size and absence of injuries. In the first stage, fruit were treated with the fungicides Sporekill® (12% dodecyl dimethyl ammonium) and Magnate 500 EC® (50% imazalil), associated or not with hydrothermal treatment at 53°C for 5 min (‘Tommy Atkins’) and 53°C for 10 min (‘Palmer’). After drying, fruits were stored at room temperature (23°C, 65% RH), and analyzed every three (‘Palmer’) or four days (‘Tommy Atkins’) for the occurrence of rots, appearance, weight loss and firmness, as well as pH and the levels of soluble solids, titable acidity and ascorbic acid in the pulp. In the second phase, the best treatment for ‘Palmer’ mangoes was combined with different protections and storage at room conditions (23°C, 65% RH) or refrigerated (12°C, 65% RH). Fruits stored with refrigeration were transferred to room conditions after 28 days for ripening evaluations 3 and 6 days later. The following treatments were used: untreated control, fungicide-treated control, low-density polyethylene film (0.050mm), multilayer polyfilm, polyvinyl chloride (PVC) film (0.017mm), and 18% carnauba wax. In the first stage, fruits from the cultivars Palmer and Tommy Atkins submitted to different treatments showed no wilting symptoms until the sixth and eighth day, respectively ...(Complete abstract

La lignine est une macromolécule, constituant de la biomasse lignocellulosique, qui est composée d’unités propylphénoliques. Cette matière est produite par l’industrie papetière en tant que coproduit de la cellulose. Actuellement, sa valorisation se limite en grande partie à des applications énergétiques. Or, la lignine peut être une source alternative de phénols si elle est dépolymérisée efficacement. Ce travail porte sur la transformation de la lignine en synthons aromatiques dans l’eau et en mélange eau-alcools en conditions sous-critique (225°C et 40-80 bar). Dans un premier temps, des études de conversion sont réalisées en réacteur fermé en utilisant l’eau comme solvant sur une lignine Kraft en présence de catalyseurs (Pt, Pd, Ru sur Al2O3,TiO2, ZrO2), le catalyseur Pd/ZrO2 nous a permis d’obtenir un rendement en phénols identifiés de 2%en 3 heures. Afin d’améliorer la conversion de la lignine en minimisant les réactions de condensations entre unités phénoliques, l’eau est remplacée par un mélange eau/alcool (éthanol, méthanol, isopropanol). La combinaison eau/isopropanol sans catalyseur nous permet d’augmenter le rendement en phénols identifiés de 5%. Nous avons ensuite essayé d’appliquer notre approche en réacteur continu. Même si le mélange eau/isopropanol était le meilleur solvant en réacteur fermé, le passage en réacteur continu s’est avéré complexe par la formation de produits solides. L’utilisation d’un mélange eau/éthanol a permis d’éviter ce problème et un rendement en gaiacol jusqu’à 1% est obtenu. L’éthanol permet de stabiliser des synthons instables dans le milieu par alkylation et estérification / Lignin is a macromolecule comprising lignocellulosic biomass, and is composed of propylphenyl units. Lignin is produced in large amounts by the paper industry when cellulose is isolated from biomass. Currently, its value is largely limited to source of energy and heat in recovery boilers. Nonetheless lignin can be an alternative source of aromatics if depolymerized effectively. The present work focuses on the transformation of lignin into aromatic building blocks using sub-critical water and mixtures of water/alcohols (225°C and 40-80 bar). Preliminary studies were carried out in a batch reactor; water was used as a solvent for the conversion of a Kraft lignin in the presence of catalysts (Pt, Pd, Ru on Al2O3, TiO2, ZrO2). The Pd/ZrO2 catalyst gave the highest yield of identified phenols with 2% in 3 hours. To improve the conversion of the lignin by minimizing condensation reactions between phenolic units, the water was replaced with a mixture water/alcohol (ethanol, methanol, isopropanol). The combination water/isopropanol without catalyst allowed us to increase the yield of identified phenols to 5%. The results obtained in batch reactor were extrapolated to a trickle-bed reactor. Even though the water/isopropanol mixture gave the best results in batch reactor, the implementation on a continuous reactor proved to be complex (formation of solids clogging the reactor). The use of a water/ethanol mixture prevented this problem and a yield in guaiacol of up to 1 % was obtained. Ethanol helps stabilize unstable building blocks by alkylation and esterification. This is evidenced by the NMR and chromatographic analysis

Palm oil empty fruit bunches (EFB) is an abundant and cheap lignocellulose material in South East Asia. Its use as the sole medium for producing lignocellulose-hydrolyzing enzymes would increase its commercial value. A newly isolated Aspergillus niger DSM 26641 was investigated for its capability of producing hemicellulases in EFB hydrolysate obtained by treatment with pressurized hot water (1-20%, w/v) at 120-180◦C in a 1 L Parr reactor for 10-60 min. The optimal hydrolysate for the fungal growth and endoxylanase production was obtained when 10% (w/v) of empty fruit bunch was treated at 120◦C or 150◦C for 10 min, giving an endoxylanase activity of 24.5 mU ml-1 on RBB-Xylan and a saccharification activity of 5 U ml-1 on xylan (DNS assay). When the hydrolysates were produced at higher temperatures, longer treatment times or higher biomass contents, only less than 20% of the above maximal endoxylanase activity was detected, possibly due to the higher carbohydrate concentrations in the medium. Transcriptome analysis showed that 3 endoxylanases (expression levels 59-100%, the highest level was set as 100%), 2 b-xylosidases (4%), 4 side chain-cleaving arabinofuranosidases (1-95%), 1 acetyl xylan esterase (9%) and 2 ferulic acid esterases (0.3-9%) were produced together.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第18606号 / エネ博第302号 / 新制||エネ||62(附属図書館) / 31506 / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 坂 志朗, 教授 杉山 淳司, 准教授 河本 晴雄 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

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L'impact de traitements hydrodrothermiques complémentaires au procédé classique de fabrication des pâtes alimentaires a été étudié afin de définir les relations "procédé / structure / propriétés". Des pâtes 100% blé dur, éventuellement enrichies en protéines, monoglycérides et amylose, ont été produites, puis traitées à la vapeur selon différents couples temps-température, puis cuites de façon conventionnelle ou stérilisées. Les caractéristiques structurales des pâtes ainsi obtenues ont été étudiées à différentes échelles après chaque étape du procédé pour déterminer l'influence des opérations unitaires et de leurs paramètres. Les traitements vapeur induisent principalement une perte de la structure cristalline d'amidon natif, la formation de complexes amylose-lipides avec l'augmentation de la température et de la teneur en eau des pâtes. De plus, la réticulation du réseau protéique est accrue avec la température et la durée du traitement. Ces modifications structurales ont été synthétisées dans un digramme d'état. Toutefois, lorsque les pâtes sont chauffées en excès d'eau, le réseau protéique peut être rompu, les complexes disparaître et l'amylopectine rétrograder. La mesure des propriétés de texture de ces produits a permis d'établir les contributions respectives du mécanisme de plastification par l'eau et des différentes entités structurales présentes dans la pâte. Ces dernières renforcent mécaniquement les pâtes et l'addition des ingrédients permet ainsi d'améliorer les propriétés des produits. Un diagramme de fabrication a été proposé à partir de l'ensemble des résultats obtenus et son application à une formulation appropriée devrait permettre de répondre à l'objectif technique de ces travaux. / The impact of hydrothermal treatments in addition to those of traditional process of pasta manufacturing has been studied to define the relationship "process / structure / properties". Pasta exclusively based on durum wheat semolina and other enriched in protein, amylose and lipids, were produced and then steamed for different time-temperature values, then boiled or sterilized. The structural characteristics of pasta were studied at different scales after each step of the process to determine the influence of unit operations and their parameters. The steam treatments mostly induce a loss of the crystal structure of native starch and the formation of complexes amylose-lipids with increasing temperature and moisture content of pasta. Moreover, the protein network was enhanced by cross-linking as much as temperature and duration of treatment increased. Theses structural changes are synthesized in a states diagram. When the pasta is heated in an excess of water, the protein network can be disrupted, complexes may disappear and amylopectine retrograde. The measurement of the rheological properties of these products have helped to assign the contribution of the mechanism of plasticization by water and of the presence of these structures. These latter mechanically reinforce the pasta and the additions of various ingredients may then improve their properties. based on these overall results, a diagram of the process has been proposed and its application with an appropriate formulation could allow to meet the technical objective of this work.

As cinzas de carvão são subprodutos da combustão de carvão mineral gerados em grandes quantidades a partir de usinas termelétricas no mundo todo. Nos últimos anos, pesquisas sobre a utilização das cinzas estão sendo desenvolvidas visando soluções sustentáveis, garantindo, assim, a preservação do meio ambiente e a saúde humana. As cinzas de carvão podem ser aproveitadas como matéria-prima para síntese de zeólita, material este que possui uma vasta gama de aplicações industriais. Em muitas dessas aplicações é requerido o uso de formas peletizadas de zeólitas. Nesse contexto, o objetivo do presente estudo foi desenvolver um método de obtenção de zeólita de cinzas leves de carvão na forma granular e avaliar seu uso como material adsorvente. A primeira etapa deste estudo consistiu na síntese e caracterização de zeólita convencional (ZCL) e de zeólita do tipo NaA com alto grau de pureza (ZA). As cinzas leves de carvão utilizadas na síntese das zeólitas foram coletadas na Usina Termelétrica Jorge Lacerda, localizada no Estado de Santa Catarina, Brasil, o maior complexo termelétrico a carvão da América Latina. O material de partida e as zeólitas sintetizadas em pó foram caracterizados em termos da composição química, composição mineralógica, morfologia, capacidade de troca catiônica, estabilidade térmica, área superficial específica, distribuição de poros e dos grupos funcionais. As fases zeolíticas formadas por tratamento hidrotérmico foram hidroxisodalita e traços de NaX. A zeólita do tipo NaA foi sintetizada por método de duas etapas apresentando grau de pureza de 84%. O valor de capacidade de troca catiônica da zeólita A com alto grau de pureza foi aproximadamente duas vezes maior do que o valor encontrado para a zeólita convencional (1,84 meq g-1 para ZCL e 3,81 meq g-1 para ZA). Na segunda etapa, os produtos zeolíticos sintetizados neste estudo foram peletizados com a aplicação de diferentes métodos. Os grânulos de zeólitas foram formados manualmente na forma de esferas na faixa de tamanho entre 3 mm e 7 mm a partir da mistura das zeólitas em pó com um ou mais agentes aglutinantes e adição de água deionizada. As diferentes metodologias experimentais de peletização das zeólitas sintetizadas foram comparadas e avaliadas por meio da determinação da capacidade de troca catiônica dos produtos obtidos, trabalhabilidade, resistência mecânica e estabilidade em água. O método de peletização no qual as argilas caulinita e bentonita foram usadas como agentes aglutinantes, na proporção de 5% em massa cada, foi considerado o melhor para a zeólita convencional. Para a zeólita A, foi selecionado o método com 10% de bentonita. Os valores de capacidade de troca catiônica dos produtos zeolíticos foram mantidos após o processo de peletização. Posteriormente foi realizado um estudo direcionado à aplicação da zeólita granular no tratamento de água. A amostra de zeólita A com alto grau de pureza peletizada, obtida pelo método otimizado, foi selecionada para ser usada como material adsorvente no processo de adsorção de íons cádmio em solução aquosa em coluna de leito fixo. Os resultados evidenciaram a potencialidade do uso da zeólita A peletizada no tratamento de efluentes. / Coal ashes are by-products of coal combustion generated in large quantities from thermoelectric plants worldwide. In recent years, research on the use of ash has been developed aiming at sustainable solutions, thus guaranteeing the preservation of the environment and human health. Coal ashes can be used as raw material for zeolite synthesis, which has a wide range of industrial applications. In many such applications the use of zeolite pelletized forms is required. In this context, the objective of the present study was to develop a method to obtain zeolite of light ash from coal in the granular form and to evaluate its use as an adsorbent material. The first step of this study was the synthesis and characterization of zeolite conventional (ZFA) and of the zeolite NaA type with a high degree of purity (ZA). The coal fly ashes used in the synthesis of the zeolites were collected in the Thermoelectric Complex Jorge Lacerda, located in the Santa Catarina State, Brazil, the largest coal burning thermoelectric complex of Latin America. The starting material and the zeolites synthesized in powder were characterized in terms of chemical composition, mineralogical composition, morphology, cation exchange capacity, thermal stability, specific surface area, pore distribution and functional groups. The zeolitic phases formed by conventional hydrothermal treatment were hydroxysodalite and traces of NaX. The zeolite of the NaA type was synthesized by a two-step method with a fusion step having a degree of purity of 84%. The value of cation exchange capacity of zeolite A with high purity was approximately two times higher than the value found for the zeolite conventional (1.84 meq g-1 for ZFA and 3.81 meq g-1 for ZA). In the second step, the zeolitic products synthesized in this study were pelletized with the application of different methods. The zeolite granules were formed manually in the form of spheres in the size range between 3 mm and 7 mm from the powder mixture of zeolite with one or more binders and addition of deionized water. The different experimental methodologies of pelletization the synthesized zeolites were compared and evaluated through of the determination of the cation exchange capacity, workability, mechanical strength and water stability. The pelletization method in which clays kaolinite and bentonite were used as binders in the proportion of 5% by weight each was considered the best for the conventional zeolite. For zeolite-A, was selected the method with 10% bentonite. The cation exchange capacity values of the zeolitic products were maintained after the pelletization process. Subsequently, a study was carried out on the application of granular zeolite in water treatment. The zeolite-A sample with high degree of pelletized purity, obtained by the optimized method, was selected to be used as adsorbent material in the adsorption process of cadmium ions in aqueous solution in a fixed bed column. The results evidenced the potential of the use of pelletized zeolite-A in the treatment of effluents.

Neste trabalho, foram realizados pré-tratamentos para maximizar o fracionamento dos componentes da biomassa e alcançar uma alta valorização do material. Relatamos uma integração de etapas de pré-tratamentos obter três produtos de alto valor agregado em um conceito de biorrefinaria: xilooligosacarídeo (XOS), xilose e celulose nanofibrilhada (CNF). Foi estudada a maximização de valor da fração hemicelulosica do bagaço de cana-de-açúcar através de extração hidrotérmica, de preferência na forma de XOS, e também se avaliou a produção de CNF, um nanomaterial emergente com inúmeras aplicações em diversos setores, como papel, têxteis e eletrônicos. Para selecionar a melhor condição de solubilização de hemicelulose na forma de XOS, as condições do processo hidrotérmicos foram avaliadas com planejamento experimental estatístico 23, com rotação do tipo estrela, a fim de analisar o efeito combinado de temperatura, tempo e concentração de ácido (H2SO4). A melhor condição experimental para produzir XOS com alto rendimento e seletividade foi a 182 °C durante 5,5 minutos e sem adição de ácido, obtendo um hidrolisado com recuperação de 43 % da xilana inicial na forma de XOS e apenas 2 % na forma de xilose. Um segundo tratamento hidrotérmico foi realizado com o objetivo de remover a xilana residual do bagaço tratado, de preferência na forma de XOS. Devido à alta recalcitrância do material, não foi possível encontrar uma condição experimental para obter alta seletividade para XOS no segundo pré-tratamento e, portanto, foi escolhido obter um hidrolisado rico em xilose, um produto que também possui diversas aplicações. As melhores condições experimentais para se obter um hidrolisado rico em xilose foram determinadas a 168 ° C durante 5,5 minutos e 1,01% m/m de H2SO4, obtendo-se uma recuperação de 36 % da xilana presente inicialmente no bagaço na forma de xilose e apenas 3 % na forma de XOS, sendo este um processo altamente seletivo para recuperação da xilana na forma monomérica. A fração sólida oriunda das etapas de extração da xilana foi deslignificada com NaOH e branqueada em duas etapas, com H2O2 em meio alcalino e com NaClO2 em meio ácido, obtendo pasta celulósica com alto teor de celulose (88,9% m/m de celulose). A polpa celulósica foi processada em um refinador de disco mecânico (SupermassColloider) para produzir celulose nanofibrilada (CNF-B). As propriedades morfológicas do CNF-B foram avaliadas e verificou-se que foi semelhante à nanocelulose de polpa Kraft (CNF-K), em relação as suas dimensões, produzida nas mesmas condições. Além disso, a produção do CNF-B consumiu cerca de um terço da energia necessária para obter o CNF-K. O balanço de massa final do processo mostrou uma alta recuperação dos carboidratos originais em produtos de alto valor agregado. A recuperação da xilana foi de cerca de 88% m/m, sendo 43% m/m de XOS e 36% m/m de xilose. O alto conteúdo recuperado dos coprodutos demonstra a alta seletividade das otimizações realizadas. Por fim, o processo obteve alta recuperação e conversão de celulose à CNF-B, com um rendimento de 88% m/m. / A pretreatment has been pursued to maximize the biomass components and achieve a high material´s valorization. Here, we report an integration of pathways, which have been effective to obtain three high value-added products in a biorefinery concept: XOS, xylose and cellulose nanofibrillated (CNF). The maximization of hemicellulose fraction was studied through hydrothermal extraction from sugarcane bagasse, preferably oligosaccharides (XOS) form, and it was also evaluated CNF production, an emerging nanomaterial with numerous applications in diverse sectors such as paper, textiles and electronics. To select the best condition of hemicellulose solubilization in the form of XOS, the hydrothermal process conditions were evaluated with statistical experimental design to analyze the combined effect of temperature, time and acid concentration (H2SO4). The best experimental condition to produce XOS with high yield and selectivity was at 182 ° C for 5.5 minutes and without acid addition, obtaining a hydrolysate with 75% w/w of XOS content, which corresponds to 43% w/w of the original xylan. A second hydrothermal treatment was performed with the aim of remove a residual xylan from treated bagasse, focusing in XOS form. Because of the high susceptibility of the material, it was not possible to find an experimental condition to achieve high selectivity for XOS in the second pretreatment and, therefore, it was chosen to obtain a hydrolyzate rich in xylose, a product with many applications as well. The best experimental conditions to the hydrolyzate system based in xylose was determined at 168 ° C for 5.5 minutes and 1.01% w/w H2SO4, obtaining a xylose\'s yields of 36% w/w (initial xylan). The solid fraction of the second hydrothermal step was deslignificated with NaOH and bleached in two steps, with H2O2 at alkaline medium and with NaClO2 at acid medium, obtaining cellulosic pulp with high cellulose content (88.9% w/w of cellulose). Cellulosic pulp was processed in a mechanical disc refiner (SupermassColloider) to produce fibrillated nanocellulose (CNF-B). The morphological properties of the CNF-B were evaluated, and it was found to be similar to Kraft pulp nanocellulose (CNF-K) produced at same conditions. Besides that, the production of CNF-B consumed about one third of the energy required to obtain CNF-K. CNF-B and CNF-K were also compared in terms of mean diameter and it was obtained 56.72 nm and 36.83 nm, respectively. The final mass balance of the process showed a high recovery of the original carbohydrates in means of high value-added product. The recovery of xylan was around 88%, being 43% w/w of XOS and 36% w/w of xylose. The high content recovered of the co-products demonstrate the high selectivity of the optimizations performed. Thus, this resulted in a high recovery and conversion of cellulose in the CNF-B with a yield of 88% w/w.

Neste trabalho, foram realizados pré-tratamentos para maximizar o fracionamento dos componentes da biomassa e alcançar uma alta valorização do material. Relatamos uma integração de etapas de pré-tratamentos obter três produtos de alto valor agregado em um conceito de biorrefinaria: xilooligosacarídeo (XOS), xilose e celulose nanofibrilhada (CNF). Foi estudada a maximização de valor da fração hemicelulosica do bagaço de cana-de-açúcar através de extração hidrotérmica, de preferência na forma de XOS, e também se avaliou a produção de CNF, um nanomaterial emergente com inúmeras aplicações em diversos setores, como papel, têxteis e eletrônicos. Para selecionar a melhor condição de solubilização de hemicelulose na forma de XOS, as condições do processo hidrotérmicos foram avaliadas com planejamento experimental estatístico 23, com rotação do tipo estrela, a fim de analisar o efeito combinado de temperatura, tempo e concentração de ácido (H2SO4). A melhor condição experimental para produzir XOS com alto rendimento e seletividade foi a 182 °C durante 5,5 minutos e sem adição de ácido, obtendo um hidrolisado com recuperação de 43 % da xilana inicial na forma de XOS e apenas 2 % na forma de xilose. Um segundo tratamento hidrotérmico foi realizado com o objetivo de remover a xilana residual do bagaço tratado, de preferência na forma de XOS. Devido à alta recalcitrância do material, não foi possível encontrar uma condição experimental para obter alta seletividade para XOS no segundo pré-tratamento e, portanto, foi escolhido obter um hidrolisado rico em xilose, um produto que também possui diversas aplicações. As melhores condições experimentais para se obter um hidrolisado rico em xilose foram determinadas a 168 ° C durante 5,5 minutos e 1,01% m/m de H2SO4, obtendo-se uma recuperação de 36 % da xilana presente inicialmente no bagaço na forma de xilose e apenas 3 % na forma de XOS, sendo este um processo altamente seletivo para recuperação da xilana na forma monomérica. A fração sólida oriunda das etapas de extração da xilana foi deslignificada com NaOH e branqueada em duas etapas, com H2O2 em meio alcalino e com NaClO2 em meio ácido, obtendo pasta celulósica com alto teor de celulose (88,9% m/m de celulose). A polpa celulósica foi processada em um refinador de disco mecânico (SupermassColloider) para produzir celulose nanofibrilada (CNF-B). As propriedades morfológicas do CNF-B foram avaliadas e verificou-se que foi semelhante à nanocelulose de polpa Kraft (CNF-K), em relação as suas dimensões, produzida nas mesmas condições. Além disso, a produção do CNF-B consumiu cerca de um terço da energia necessária para obter o CNF-K. O balanço de massa final do processo mostrou uma alta recuperação dos carboidratos originais em produtos de alto valor agregado. A recuperação da xilana foi de cerca de 88% m/m, sendo 43% m/m de XOS e 36% m/m de xilose. O alto conteúdo recuperado dos coprodutos demonstra a alta seletividade das otimizações realizadas. Por fim, o processo obteve alta recuperação e conversão de celulose à CNF-B, com um rendimento de 88% m/m. / A pretreatment has been pursued to maximize the biomass components and achieve a high material´s valorization. Here, we report an integration of pathways, which have been effective to obtain three high value-added products in a biorefinery concept: XOS, xylose and cellulose nanofibrillated (CNF). The maximization of hemicellulose fraction was studied through hydrothermal extraction from sugarcane bagasse, preferably oligosaccharides (XOS) form, and it was also evaluated CNF production, an emerging nanomaterial with numerous applications in diverse sectors such as paper, textiles and electronics. To select the best condition of hemicellulose solubilization in the form of XOS, the hydrothermal process conditions were evaluated with statistical experimental design to analyze the combined effect of temperature, time and acid concentration (H2SO4). The best experimental condition to produce XOS with high yield and selectivity was at 182 ° C for 5.5 minutes and without acid addition, obtaining a hydrolysate with 75% w/w of XOS content, which corresponds to 43% w/w of the original xylan. A second hydrothermal treatment was performed with the aim of remove a residual xylan from treated bagasse, focusing in XOS form. Because of the high susceptibility of the material, it was not possible to find an experimental condition to achieve high selectivity for XOS in the second pretreatment and, therefore, it was chosen to obtain a hydrolyzate rich in xylose, a product with many applications as well. The best experimental conditions to the hydrolyzate system based in xylose was determined at 168 ° C for 5.5 minutes and 1.01% w/w H2SO4, obtaining a xylose\'s yields of 36% w/w (initial xylan). The solid fraction of the second hydrothermal step was deslignificated with NaOH and bleached in two steps, with H2O2 at alkaline medium and with NaClO2 at acid medium, obtaining cellulosic pulp with high cellulose content (88.9% w/w of cellulose). Cellulosic pulp was processed in a mechanical disc refiner (SupermassColloider) to produce fibrillated nanocellulose (CNF-B). The morphological properties of the CNF-B were evaluated, and it was found to be similar to Kraft pulp nanocellulose (CNF-K) produced at same conditions. Besides that, the production of CNF-B consumed about one third of the energy required to obtain CNF-K. CNF-B and CNF-K were also compared in terms of mean diameter and it was obtained 56.72 nm and 36.83 nm, respectively. The final mass balance of the process showed a high recovery of the original carbohydrates in means of high value-added product. The recovery of xylan was around 88%, being 43% w/w of XOS and 36% w/w of xylose. The high content recovered of the co-products demonstrate the high selectivity of the optimizations performed. Thus, this resulted in a high recovery and conversion of cellulose in the CNF-B with a yield of 88% w/w.

Les zéolithes sont largement utilisées en catalyse acide, particulièrement en pétrochimie. Toutefois, leur activité n'est pas optimale à cause des limitations diffusionnelles imposées par leur structure microporeuse. Diverses approches ont été proposées pour contourner ces limitations et notamment la préparation des zéolithes mésoporeuses. Après une évaluation industrielle des différentes méthodes rapportées dans la littérature, la première partie de la thèse a été consacrée à la mise au point, la compréhension et l'optimisation d'une procédure de préparation de zéolithes à mésoporosité contrôlée à l'aide d'un agent structurant organique. Nous nous sommes intéressés à la recristallisation de la zéolithe Y qui permet de créer un volume mésoporeux important au sein des cristaux de zéolithe par transformation pseudomorphique. Dans une seconde partie, nous rapportons la première synthèse de zéolithes mésoporeuses à partir d'un agent structurant récupérable et recyclable en conditions douces dans l'eau. En synthétisant un agent structurant thermosensible adapté aux conditions de recristallisation, une mésostructure contrôlée a pu être obtenue au sein de la zéolithe. L'extraction du polymère en solution aqueuse a été optimisée et son recyclage sur quatre cycles de recristallisation a été démontré. / Zeolites are widely used in acid catalysis, especially in petrochemistry. However, their activity is not optimal because of diffusional limitations imposed by their microporous structure. Various approaches have been proposed to circumvent these limitations, including the preparation of mesoporous zeolites. After an industrial assessment of the different methods reported in the literature, the first part of the thesis was devoted to the development, understanding and optimization of a procedure for preparation of zeolites with controlled mesoporosity using an organic structuring agent. We studied the recrystallization of the zeolite Y, which creates a large mesoporous volume in the zeolite crystals by pseudomorphic transformation. In the second part, we report the first synthesis of mesoporous zeolites using a structuring agent recoverable and recyclable under mild conditions in water. By synthesizing a structuring agent adapted to the conditions of thermal recrystallization, controlled mesostructure could be obtained within the zeolite. The extraction of the polymer in aqueous solution has been optimized and recycling of four cycles of recrystallization has been demonstrated.