O setor de Celulose e Papel é um importante segmento da economia brasileira e contribui significativamente para a pauta de exportações do país. O Brasil se destaca no mercado mundial como o principal produtor de polpa celulósica de fibra curta branqueada, especificamente produzida a partir de madeiras do gênero Eucalyptus. Na última década observou-se um novo ciclo de crescimento dessa indústria no Brasil. Este trabalho teve como principais objetivos definir a situação atual do Brasil no mercado mundial de polpa celulósica, avaliar a competitividade brasileira do segmento de celulose de mercado no período de 2000 a 2009, analisar as empresas brasileiras mais expressivas e avaliar aspectos relativos à inovação neste segmento. Para a realização deste trabalho foram utilizadas as bases de dados da FAO, SECEX, BRACELPA e RISI; foram calculados índices de competitividade visando a análise comparativa entre os principais países ligados ao segmento de celulose de mercado. Os resultados obtidos mostram que o Brasil é o terceiro maior produtor mundial de polpa proveniente de madeira (wood pulp), é líder em exportação de wood pulp, é o maior produtor mundial de celulose de fibra curta branqueada e é o segundo país mais competitivo; a implantação dos projetos de expansão da produção de polpa celulósica conforme previsto, poderá levar o Brasil ao segundo lugar no ranking mundial dos produtores de celulose; a demanda mundial de polpa branqueada de fibra curta de mercado cresceu no período analisado, em grande parte pela demanda da China, que atualmente ocupa a oitava posição no ranking de produtores de polpa celulósica de madeira wood pulp; destaca-se que a China é um grande produtor mundial de polpa celulósica obtida a partir de não madeiras (non-wood pulp); as maiores empresas brasileiras de celulose de mercado (Fibria Celulose S.A. e Suzano Papel e Celulose S.A.) representam 56,2% da produção brasileira de celulose (market share) e 12,4% da produção mundial de polpa de mercado (market pulp); as duas empresas analisadas neste trabalho apresentam parques industriais modernos e as inovações são na sua grande maioria incrementais; os dados da PINTEC para o segmento de polpa celulósica e outras pastas, da forma disponibilizada, não caracterizam adequadamente este segmento, pois não ponderam os resultados pela participação das empresas no mercado. / The pulp and paper sector is an important segment of the Brazilian economy and contributes significantly to the overall exports of the country. Brazil stands on the world market as the main producer of bleached hardwood pulp, specially produced from wood of Eucalyptus. In the last decade there was a new cycle of growth of this industry in Brazil. This work had as main objective to define the current situation of Brazil in the global pulp market, to evaluate the competitiveness of the Brazilian market pulp segment in the period between 2000 and 2009, Brazilian companies were analyzed and evaluated the most significant aspects of innovation in this segment. For this work were used the databases of the FAO, SECEX BRACELPA and RISI; competitiveness indexes were calculated with the aim of benchmarking the major countries linked to the segment of market pulp. The results show that Brazil is the third largest producer of pulp from wood pulp, is a leader in exports of wood pulp, is the largest producer of bleached hardwood pulp and is the second most competitive country; the implementation of projects to expand pulp production as planned, could lead Brazil to second place in the world of pulp producers, the global demand for market bleached hardwood pulp has grown over this period, largely by demand from China, which currently occupies the eighth position in the ranking of wood pulp producers; it should be emphasized that China is the major global producer of non-wood pulp; the largest Brazilian market pulp companies (Fibria Celulose S.A. and Suzano Papel e Celulose S.A.) have a market share of 56.2% of Brazilian pulp production and 12.4% of the world market pulp production; the two companies analyzed in this study have modern industrial areas and the innovations are mostly incremental. PINTEC data for the pulp segment, as presented, does not adequately characterize this segment because they do not weight the results for the contribution of the companies in the market.

No description available.

Dynamic (or 2D) FT-IR spectroscopy in combination withpolarized IR irradiation has been used in this work to studywood polymer orientation and interactions on theultrastructural level in wood fibers in the native state aswell as the effects of different pulping processes. The woodpolymer interactions were studied under both dry and humidconditions. The matrix of lignin and hemicelluloses located between thewell-ordered cellulose fibrils in the wood cell wall of sprucewas here shown to be more highly ordered than has earlier beenrevealed. It was confirmed that glucomannan is orientedparallel to the cellulose fibrils and is highly coupled to it.The lignin was also shown to have a main orientation in thestructure although this is probably not as strong as that ofglucomannan. The orientation of the lignin may derive from thefact that the polysaccharides act as templates during thelignification of the cell wall. This organization implies thatnot only the cellulose but also the lignin and thehemicelluloses have different mechanical properties in thelongitudinal and cross-fiber directions. The ability to gain molecular information on the stresstransfer in polymers with dynamic FT-IR spectroscopy made itpossible to verify experimentally earlier molecularcalculations on the stress transfer within the cellulose chain.It was also possible to show, on the molecular level, thedominant importance of the cellulose fibrils for the stresstransfer in the longitudinal direction of pulp fibers,including lignin-rich mechanical pulp fibers. The glucomannanof softwood fibers was also shown to participate in the stresstransfer in the fiber direction indicating a close associationwith the cellulose, whereas the xylan showed no dynamicresponse. Already under dry conditions, the lignin was shown tohave a more viscoelastic response than the polysaccharidesduring the loading of pulp fibers and it was thus able to moveindependently of the cellulose. The enhanced spectral resolution obtained with dynamic FT-IRspectroscopy made it possible to study the crystalstructure/chain order of cellulose in pulp fibers. Thepossibility of following changes in the relative cellulose Iallomorph composition of pulp fibers was demonstrated for somechemical pulps. Dynamic FT-IR experiments under humid conditions and ofelevated temperatures made it possible to study the softeningof the biopolymers in their native environment. This was alsodemonstrated for some different pulps, and this may be apromising tool for obtaining viscoelastic information on themolecular level in composite systems such as wood fibers. <b>Keywords:</b>cellulose, cooperation, crystallinity, dynamictest, glucomannan, hardwood, holocellulose, humidity, infraredspectroscopy, kraft pulp, lignin, mechanical pulp, orientation,polarised light, softwood, strain, sulphite pulp,viscoelasticity, xylan

No description available.

<p>Dynamic (or 2D) FT-IR spectroscopy in combination withpolarized IR irradiation has been used in this work to studywood polymer orientation and interactions on theultrastructural level in wood fibers in the native state aswell as the effects of different pulping processes. The woodpolymer interactions were studied under both dry and humidconditions.</p><p>The matrix of lignin and hemicelluloses located between thewell-ordered cellulose fibrils in the wood cell wall of sprucewas here shown to be more highly ordered than has earlier beenrevealed. It was confirmed that glucomannan is orientedparallel to the cellulose fibrils and is highly coupled to it.The lignin was also shown to have a main orientation in thestructure although this is probably not as strong as that ofglucomannan. The orientation of the lignin may derive from thefact that the polysaccharides act as templates during thelignification of the cell wall. This organization implies thatnot only the cellulose but also the lignin and thehemicelluloses have different mechanical properties in thelongitudinal and cross-fiber directions.</p><p>The ability to gain molecular information on the stresstransfer in polymers with dynamic FT-IR spectroscopy made itpossible to verify experimentally earlier molecularcalculations on the stress transfer within the cellulose chain.It was also possible to show, on the molecular level, thedominant importance of the cellulose fibrils for the stresstransfer in the longitudinal direction of pulp fibers,including lignin-rich mechanical pulp fibers. The glucomannanof softwood fibers was also shown to participate in the stresstransfer in the fiber direction indicating a close associationwith the cellulose, whereas the xylan showed no dynamicresponse. Already under dry conditions, the lignin was shown tohave a more viscoelastic response than the polysaccharidesduring the loading of pulp fibers and it was thus able to moveindependently of the cellulose.</p><p>The enhanced spectral resolution obtained with dynamic FT-IRspectroscopy made it possible to study the crystalstructure/chain order of cellulose in pulp fibers. Thepossibility of following changes in the relative cellulose Iallomorph composition of pulp fibers was demonstrated for somechemical pulps.</p><p>Dynamic FT-IR experiments under humid conditions and ofelevated temperatures made it possible to study the softeningof the biopolymers in their native environment. This was alsodemonstrated for some different pulps, and this may be apromising tool for obtaining viscoelastic information on themolecular level in composite systems such as wood fibers.</p><p><b>Keywords:</b>cellulose, cooperation, crystallinity, dynamictest, glucomannan, hardwood, holocellulose, humidity, infraredspectroscopy, kraft pulp, lignin, mechanical pulp, orientation,polarised light, softwood, strain, sulphite pulp,viscoelasticity, xylan</p>

Les pâtes à dissoudre, composées à 95% de cellulose, sont la matière première pour la production de fibres cellulosiques régénérées (viscose, Lyocell…) et de dérivés cellulosiques (ester, éther ou nitrate de cellulose). En tant qu’alternative aux matériaux issus de ressources pétrolières, ces produits connaissent actuellement un fort regain d’intérêt. Ainsi, la production de pâte à dissoudre devrait croître fortement au cours de la prochaine décennie. L’objectif de cette thèse est de proposer des procédés de conversion d’une pâte papetière de résineux en pâte à dissoudre. Pour cela les hémicelluloses présentes dans les pâtes kraft papetières doivent être extraites. Trois méthodes d’extraction d’hémicelluloses ont ainsi été étudiées : (1) une extraction alcaline à froid (CCE) dans des conditions non conventionnelles, (2) un procédé se divisant en deux étapes successives : un stade acide à haute température (150°C) suivie d’une extraction alcaline à chaud (AHCE) et (3) une hydrolyse enzymatique par trois enzymes commerciales (une xylanase, une mannanase, une cellulase). Les deux premières méthodes ont permis de produire des pâtes avec des caractéristiques proches des pâtes à dissoudre commerciales. Cependant, dans les trois voies d’extraction étudiées, l’extraction d’hémicelluloses n’a jamais atteint 100%. Des prétraitements des pâtes (raffinage, explosion à la vapeur, oxydation TEMPO) ont alors été testés pour améliorer l’extraction des hémicelluloses. De nouvelles séquences de purification basées sur la combinaison d’une étape de raffinage suivie d’une extraction alcaline à froid (CCE) peuvent être ainsi imaginées. La dernière partie de ces travaux de thèse s’est intéressée au gonflement des pâtes à dissoudre. Les travaux ont abouti à la création d’une nouvelle méthode simple et rapide de caractérisation du gonflement des fibres de pâte cellulosique. Cette méthode de mesure peut être, dans certaines conditions, considérée comme une mesure alternative de la réactivité des pâtes à dissoudre habituellement caractérisée par le test Fock. / Dissolving pulps, which are composed of 95% cellulose, are the raw materials for the production of regenerated cellulose fibres for textile application and for the production of cellulose derivatives. These products are alternatives to oil based materials. A growing demand in such products is expected in the next decades. Therefore, additional capacities in the production of wood dissolving pulp must be created. The purpose of this work is to develop hemicellulose removal processes with the aim to convert a softwood kraft paper pulp into a dissolving pulp. Three extraction methods were tested: (1) A cold caustic extraction process (CCE) performed under conventional and unconventional conditions; (2) A process consisting in an acid stage at high temperature (up to 150°C) followed by a hot caustic extraction (A-HCE); (3) An enzymatic hydrolysis using xylanase, mannanase, and cellulase. Conversion was quite successful with the two first processes. However, 100% of hemicellulose removal was never reached. In order to improve the hemicellulose extraction efficiency, several pre-treatments were tested (refining, steam explosion, TEMPO oxidation). The addition of a refining stage allows a reduction of the NaOH concentration during CCE extraction without affecting the hemicellulose extraction efficiency. The last part of this thesis work focus on the dissolving pulp swelling. A new and rapid test for the characterization of fibre swelling was developed. This method was used as an approach to the assessment of dissolving pulp reactivity in the viscose process in place of the Fock’s method.

Made available in DSpace on 2015-03-26T13:28:03Z (GMT). No. of bitstreams: 1 texto completo.pdf: 921341 bytes, checksum: 446b365083b78b0c2838f6e14f0457d3 (MD5) Previous issue date: 2011-05-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Bleached kraft pulp production generates large volumes of wastewater. During the process, wood components such as lignin, extractives and fibers are removed and contribute to the organic load of these effluents. Pulp mill wastewater treatment is usually performed by biological processes but part of the organic load has low biodegradability (or high recalcitrance) and is not removed by the treatment. Moreover, some of these compounds be toxic and decrease survival and, or reproduction in aquatic organisms. Pulp mill effluents are commonly treated in activated sludge plants. This system consists of an aeration tank, where organic matter is removed by biomass (biological sludge), and a sedimentation tank (secondary sedimentation), where effluent clarification occurs through settling of the biological sludge, which is recycled to the aeration tank, which allows increasing the biomass concentration and contributes to greater treatment efficiency. The moving bed biofilm reactor (MBBR) has emerged as a new activated sludge system configuration aimed at greater organic matter removal efficiency combined with greater stability, lower solids production and less need for nutrients. In this system, the aeration tank is filled with plastic biofilm carriers that are suspended and in continuous movement within the aeration tank, permitting growth of biomass in both dispersed and biofilm forms. This configuration allows greater biomass retention and may result in better recalcitrant organic matter or toxicity removal from industrial effluent. This study compared activated sludge and MBBR systems in parallel with the MBBR with hydraulic retention times of 12 and 24 hours, and the reactors in series (with MBBR after the activated sludge system), with regard to removal of organic matter, extractives, lignin, phenolic compounds and toxicity of bleached kraft pulp mill effluent, as well as EPS production by biological sludge. Both systems showed high organic matter removal efficiency with no statistically significant differences between reactor configurations. In relation to recalcitrant compounds, the MBBR was more efficient than the activated sludge system in extractives removal, but there was no difference in removal of lignin or phenolic compounds. Protein contents were higher in EPS produced by biological sludge in the reactors operated in series than in parallel. In general, the chronic toxicity to Ceriodaphnia dubia was eliminated through biological treatment, independently of the system or hydraulic retention time. In general, theMBBR and activated sludge systems behaved similarly for most of the parameters analyzed and configurations evaluated. / O processo de produção de polpa celulósica kraft branqueada é conhecido pela geração de grande volume de efluentes. Durante o processo, componentes da madeira, como lignina, extrativos e fibras, são removidos e contribuem para o aumento da carga orgânica destes efluentes. O tratamento destas águas residuárias normalmente é realizado por processos biológicos e parte destes compostos orgânicos possui baixa biodegradabilidade (ou alta recalcitrância) e não são removidos durante o tratamento. Além disso, alguns desses compostos apresentam efeitos tóxicos e podem causar problemas em relação à sobrevivência e, ou reprodução de organismos aquáticos. Um dos processos biológicos mais utilizados por indústrias de polpa celulósica é o sistema de lodos ativados. Este sistema é composto por um tanque de aeração, no qual ocorre a remoção da matéria orgânica através de sua utilização por uma biomassa (lodo biológico), e um decantador (decantador secundário), no qual ocorre a clarificação do efluente através da sedimentação dos sólidos em suspensão. O fornecimento do oxigênio é realizado por aeradores superficiais, sopradores de ar ou injeção de oxigênio puro. O sistema apresenta ainda uma linha de recirculação de lodo, responsável pelo retorno da biomassa decantada ao tanque de aeração, o que permite o aumento da concentração da biomassa e contribui para uma maior eficiência do tratamento. O reator de biofilme e leito móvel (MBBR) surgiu como uma nova configuração do sistema de lodos ativados visando maior eficiência de remoção de matéria orgânica combinada com maior estabilidade, menor produção de sólidos e menor necessidade de nutrientes. Neste sistema, o tanque de aeração é preenchido com meios suportes que possibilitam o crescimento aderido juntamente com o crescimento disperso no meio líquido. Esta configuração permite maior retenção da biomassa e pode implicar em uma maior remoção de matéria orgânica recalcitrante ou tóxica de efluentes industriais. O presente estudo comparou o sistema de lodos ativados e reator MBBR operados em paralelo com tempos de detenção hidráulica de 12 e 24 horas, além dos reatores em série (com o MBBR após o sistema de lodos ativados). Foram avaliadas as eficiências dos sistemas em relação à remoção de matéria orgânica, extrativos, lignina, compostos fenólicos e toxicidade do efluente de uma fábrica de polpa kraft branqueada de eucalipto, além de produção de EPS pelo lodo biológico. Os resultados indicaram grande eficiência de remoção de matéria orgânica de ambos os sistemas nas diferentes configurações testadas, e não foram observadas diferenças significativas entre os tratamentos. Em relação aos compostos recalcitrantes, o MBBR apresentou-se mais eficiente na remoção de extrativos do que o sistema de lodos ativados, mas não houve diferença significativa para a remoção de compostos fenólicos. Em geral, o tratamento biológico foi capaz de eliminar a toxicidade a Ceriodaphnia dubia, independentemente do reator ou tempo de detenção hidráulico. De maneira geral, o reator MBBR comportou-se de maneira semelhante ao sistema de lodos ativados, para a maioria dos parâmetros analisados e para as configurações testadas.

Made available in DSpace on 2015-03-26T13:28:30Z (GMT). No. of bitstreams: 1 texto completo.pdf: 402091 bytes, checksum: c86b326d507251f55728ecbdac152bce (MD5) Previous issue date: 2007-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Bleached kraft pulp and textile effluents contain hard to degrade and, or toxic substances, and these industries often cannot meet legal limits for effluent chemical oxygen demand using conventional effluent treatment. Use of advanced oxidation processes (AOPs) is therefore being studied to treat their effluents. AOPs use a strong oxidizing agent to degrade organic matter but present high cost and data on their application in industrial effluents is lacking. The objective of this study was therefore to evaluate efficiency of combining AOPs (TiO2/UV, H2O2/UV, H2O2/TiO2/UV) with aerobic biological treatment to increase removal of recalcitrant organic matter in industrial effluents. Neither pretreatment of alkaline bleached kraft pulp effluent nor post-treatment of combined bleached kraft pulp effluent by the AOPs resulted in increased effluent biodegradability probably because of high effluent chloride levels. Under the conditions studied, the AOPs were not able to attack and degrade the recalcitrant organic matter in the kraft pulp effluent, contrary to literature reports. However, AOP treatment of acid bleached kraft pulp effluent should be evaluated since a beneficial effect of the AOPs was observed at low effluent pH. Pretreatment of textile effluent presented favorable results with the best treatment being 5 mmol L-1 H2O2/TiO2/UV. However, the efficiency of the process decreased with the increase in concentration of organic matter in the raw effluent. Even after aerobic biological treatment to reduce COD (755 mg L-1), satisfactory results were not obtained. For the textile effluent, the effect of COD concentration on AOP efficiency should be studied in greater detail since these processes present potential as a pretreatment. / Os efluentes das indústrias de celulose kraft branqueada e têxtil contêm substâncias de difícil degradação e, ou tóxicas. Estas indústrias, através de tratamentos convencionais não conseguem atingir a legislação com relação à demanda química de oxigênio. Devido a este fato, estuda-se o uso de processos oxidativos avançados (POAs) para tratar estes efluentes. Os POAs são processos que utilizam um oxidante forte para degradar a matéria orgânica, no entanto, apresentam altos custos, faltando dados de sua aplicação em efluentes reais. Portanto, o objetivo deste trabalho foi avaliar a eficiência dos POAs no tratamento de efluentes reais, juntamente com o tratamento biológico para aumentar a remoção da matéria orgânica recalcitrante. Para o efluente de celulose kraft, os POAs, tanto no pré-tratamento do efluente alcalino como no pós-tratamento do efluente combinado, não resultaram em aumento da biodegradabilidade, provavelmente devido ao alto teor de cloretos no efluente. Contudo, recomenda-se que se faça um estudo com o efluente ácido já que se observou um efeito benéfico de realizar o pré-tratamento oxidativo em pH baixo. Portanto, nas condições estudadas os POAs não conseguiram atacar a matéria orgânica recalcitrante nos efluentes da indústria de celulose, ao contrário dos relatos encontrados na literatura. O efluente têxtil apresentou resultados favoráveis no pré-tratamento, com o melhor tratamento sendo com 5 mmol L-1 H2O2/TiO2/UV. Porém, a eficiência do processo diminuiu com o aumento da concentração da matéria orgânica no efluente bruto. Mesmo após o tratamento biológico aeróbio no laboratório para reduzir a DQO (DQO = 755 mg L-1) não foi obtido um resultado satisfatório. Para o efluente têxtil, recomenda-se estudar mais detalhadamente o efeito da concentração de DQO do efluente sobre os POAs, uma vez que os mesmos apresentam potencial como pré-tratamento.

O setor de Celulose e Papel é um importante segmento da economia brasileira e contribui significativamente para a pauta de exportações do país. O Brasil se destaca no mercado mundial como o principal produtor de polpa celulósica de fibra curta branqueada, especificamente produzida a partir de madeiras do gênero Eucalyptus. Na última década observou-se um novo ciclo de crescimento dessa indústria no Brasil. Este trabalho teve como principais objetivos definir a situação atual do Brasil no mercado mundial de polpa celulósica, avaliar a competitividade brasileira do segmento de celulose de mercado no período de 2000 a 2009, analisar as empresas brasileiras mais expressivas e avaliar aspectos relativos à inovação neste segmento. Para a realização deste trabalho foram utilizadas as bases de dados da FAO, SECEX, BRACELPA e RISI; foram calculados índices de competitividade visando a análise comparativa entre os principais países ligados ao segmento de celulose de mercado. Os resultados obtidos mostram que o Brasil é o terceiro maior produtor mundial de polpa proveniente de madeira (wood pulp), é líder em exportação de wood pulp, é o maior produtor mundial de celulose de fibra curta branqueada e é o segundo país mais competitivo; a implantação dos projetos de expansão da produção de polpa celulósica conforme previsto, poderá levar o Brasil ao segundo lugar no ranking mundial dos produtores de celulose; a demanda mundial de polpa branqueada de fibra curta de mercado cresceu no período analisado, em grande parte pela demanda da China, que atualmente ocupa a oitava posição no ranking de produtores de polpa celulósica de madeira wood pulp; destaca-se que a China é um grande produtor mundial de polpa celulósica obtida a partir de não madeiras (non-wood pulp); as maiores empresas brasileiras de celulose de mercado (Fibria Celulose S.A. e Suzano Papel e Celulose S.A.) representam 56,2% da produção brasileira de celulose (market share) e 12,4% da produção mundial de polpa de mercado (market pulp); as duas empresas analisadas neste trabalho apresentam parques industriais modernos e as inovações são na sua grande maioria incrementais; os dados da PINTEC para o segmento de polpa celulósica e outras pastas, da forma disponibilizada, não caracterizam adequadamente este segmento, pois não ponderam os resultados pela participação das empresas no mercado. / The pulp and paper sector is an important segment of the Brazilian economy and contributes significantly to the overall exports of the country. Brazil stands on the world market as the main producer of bleached hardwood pulp, specially produced from wood of Eucalyptus. In the last decade there was a new cycle of growth of this industry in Brazil. This work had as main objective to define the current situation of Brazil in the global pulp market, to evaluate the competitiveness of the Brazilian market pulp segment in the period between 2000 and 2009, Brazilian companies were analyzed and evaluated the most significant aspects of innovation in this segment. For this work were used the databases of the FAO, SECEX BRACELPA and RISI; competitiveness indexes were calculated with the aim of benchmarking the major countries linked to the segment of market pulp. The results show that Brazil is the third largest producer of pulp from wood pulp, is a leader in exports of wood pulp, is the largest producer of bleached hardwood pulp and is the second most competitive country; the implementation of projects to expand pulp production as planned, could lead Brazil to second place in the world of pulp producers, the global demand for market bleached hardwood pulp has grown over this period, largely by demand from China, which currently occupies the eighth position in the ranking of wood pulp producers; it should be emphasized that China is the major global producer of non-wood pulp; the largest Brazilian market pulp companies (Fibria Celulose S.A. and Suzano Papel e Celulose S.A.) have a market share of 56.2% of Brazilian pulp production and 12.4% of the world market pulp production; the two companies analyzed in this study have modern industrial areas and the innovations are mostly incremental. PINTEC data for the pulp segment, as presented, does not adequately characterize this segment because they do not weight the results for the contribution of the companies in the market.

O presente estudo analisou a influência de clones do híbrido de Eucalyptus grandis x Eucalyptus urophylla, com densidades básicas e cargas de álcali ativo diferentes, no processo de polpação e branqueamento. As características e propriedades das polpas não-branqueadas, licor preto residual, branqueamento, morfologia e propriedades físico-mecânicas das polpas branqueadas foram analisadas para avaliar os efeitos dos fatores clone e carga de álcali ativo. As polpações foram realizadas aplicando-se cargas de álcali ativo de 12,5%, 13,5% e 14,5%. Em seguida, as polpas não-branqueadas foram submetidas a uma pré-deslignificação com oxigênio e branqueadas através da seqüência D0EOPD1. As polpas branqueadas foram refinadas em moinho PFI e analisadas quanto às resistências físico-mecânicas. Os resultados obtidos indicam que a madeira do clone G-31 apresentou menor densidade básica e teor de holocelulose, e maiores teores de extrativos totais e lignina Klason comparativamente à madeira do clone C-41. Os clones mostraram rendimentos bruto e depurado semelhantes. O clone G-31 produziu polpa com menor número kappa na menor carga alcalina e polpa com maior número kappa na maior carga alcalina revelando uma importante interação significativa clone x álcali ativo. Os fatores álcali ativo, clone e interação clone x álcali ativo tiveram influências nos parâmetros avaliados na polpação. Os licores residuais dos clones apresentaram valores semelhantes de pH, teor de sólidos solúveis, densidade e álcalis residuais. O clone G-31 consumiu mais álcali ativo residual. O fator que exerceu maior influência nestes parâmetros foi a carga de álcali ativo. O branqueamento mostrou para o clone G-31 maior eficiência na prédeslignificação com oxigênio e menor número kappa. A viscosidade intrínseca da celulose branqueada e a alvura foram mais elevadas para o clone C-41. O aumento da carga alcalina reduziu ligeiramente a alvura do clone G-31 e elevou a alvura do clone C-41. Os fatores álcali ativo, clone e interação clone x álcali ativo tiveram influências nos parâmetros avaliados no branqueamento. A fibra da polpa branqueada do clone G-31 apresentou, significativamente, maiores comprimento, espessura da parede, índice de enfeltramento, fração parede e índice de Runkel; e menores diâmetro do lume, coeficiente de flexibilidade e “coarseness”. O menor valor de “coarseness” mostrou fibras mais leves na polpa do clone G-31. O fator clone exerceu a maior influência nas propriedades físicas e mecânicas da polpa branqueada. A polpa branqueada do clone G-31 apresentou, significativamente, menor número de revoluções no moinho PFI para atingir o índice de tração de 70 N.m/g, baixo grau Schopper Riegler para atingir este nível de tração e gerou folhas com valores mais elevados de volume específico e opacidade. Estas características e propriedades permitiram concluir que a polpa do clone G-31 foi a mais atrativa e indicada para a fabricação de papéis de imprimir e escrever. A polpa branqueada do clone C-41 apresentou valores mais elevados de volume específico aparente e ascensão capilar Klemm quando analisadas sem refino. Estas propriedades foram mais evidentes nas cargas alcalinas mais elevadas. A polpa do clone C-41 mostrou características mais favoráveis para a fabricação de papéis para fins sanitários. / The present study has analyzed the influences of Eucalyptus grandis x Eucalyptus urophylla hybrid clones with different specific gravity and active alkali charges in the bleaching and pulping process. The characteristics and properties of unbleached pulp, residual black liquor, bleaching, bleached fiber morphology and bleached pulp physical-mechanical properties were analyzed to evaluate the effects of the active alkali charge and clone factors. The pulping were realized applying active alkali charges of 12,5%, 13,5% and 14,5%. Then, the unbleached pulps were submitted to an oxygen delignification and bleached with the sequence D0EOPD1. The bleached pulps were refined using PFI mill and the physical-mechanical properties were analyzed. The results showed that G-31 wood clone presented lower specific gravity and holocellulose content and higher total extractives and Klason lignin contents when compared to C-41 wood clone. Both of them showed similar pulp yield total and screening. The G-31 clone produced pulp with lower kappa number in the lowest alkaline charge and pulp with higher kappa number in the highest alkaline charge showing an important significant interaction between clone and active alkali. The factors active alkali, clone and clone x active alkali interaction influenced in the evaluated parameters in the pulping. The clones residual black liquor showed similar values of pH, soluble solids content, density and residual alkalis. The G-31 clone consumed more residual active alkali. The factor that exerted the highest influence in these parameters was the active alkali charge. The bleaching showed that the G-31 clone has higher efficiency in the oxygen delignification and lower kappa number. The bleached pulp viscosity and brightness were higher for C-41 clone. The increase in the alkaline charge reduced slightly the G-31 clone brightness and elevated the C-41 clone brightness. The factors active alkali, clone and clone x active alkali interaction influenced in the bleaching parameters evaluated. The fiber of the G-31 bleached pulp showed, significantly, higher length, wall thickness, felting index, wall ratio and Runkel index, and lower lumen diameter, flexibility coefficient and coarseness. The lowest value of coarseness showed lighter fibers in the G-31 pulp. The factor clone exerted the highest influence in the physical and mechanical properties of the bleached pulp. The G-31 bleached pulp showed, significantly, lowest revolutions number in the PFI mill to reach tensile index of 70 N.m/g, low Schopper Riegler degree to reach this tensile index and generated sheets with higher values to bulk and opacity. These characteristics and properties allow to conclude that G-31 pulp was the most attractive and indicated to produce printing and writing papers. The bleached pulp of C-41 clone showed higher values of bulk and capillarity Klemm when analyzed without refining. These properties were more evident in the highest alkaline charges. The C-41 pulp showed characteristics more favorable to the production of tissue papers.