Bamboo kraft pulping

Despite of the wide use worldwide, the industrial potential of bamboo species in Brazil is not much investigated. However, some encouragement to revert this situation was created in last few years. The aim of this research was to evaluate the technological characteristics of the Bambusa vulgaris biomass for the production of pulp by the kraft process. The technological characteristics of the raw material were determined by the basic density, the chemical composition and the morphology of the fibers. The cooking process was carried out with the application of eight charges of active alkali, in 90 minutes of heating time and 60 minutes in the maximum temperature of 170ºC. All analyzes were also executed with the Eucalyptus spp. and the Pinus spp., in order to make a complete comparison among the species Bambusa vulgaris and the two most used raw materials for the pulp production in Brazil. The Bambusa vulgaris presented a higher basic density, lower holocellulose content and a higher total extractive content. Its fibers have intermediate length and wall thickness, similar to the Eucalyptus spp. and the Pinus spp. Considering the kraft pulping process, the species Bambusa vulgaris demonstrated to be easier to delignify besides presenting almost zero reject content and smaller consumption of active alkali. However, the Eucalyptus spp. and the Pinus spp. obtained the best yields, the lowest specific consumption of raw material and better selectivities

Wood quality of 10 clonal progenies of rubber tree as raw material for bioenergy

The use of wood as a bioenergetic source requires knowledge of its technical properties. The rubber tree Hevea brasiliensis has an economic life cycle of 25 to 30 years in Brazil. It is used for extracting rubber and generating residual wood for fuel. Our goal was to characterize the wood quality of 10 clonal progenies as a source of raw material for bioenergy. Ten clonal progenies of 12-year-old Hevea brasiliensis from an experimental planting in Selvíria municipality were evaluated. Three trees per clone were evaluated for individual properties of Higher Heating Value, immediate chemical analysis, chemical composition, fiber dimensions, thermogravimetric analysis of wood under nitrogen atmosphere and Fourier Transform Infrared Spectrosocopy analysis. We highlight clone IAC 311 for fuel because it presents elevated Higher Heating Value and fixed carbon and less volatile material. However, the other genetic materials studied also meet the specifications for energy use and can be highly viable given their physical, chemical, energy, and thermal properties

Conversion of the Kraft process in soda-DDA (di-sodium salt of 1,4-Dihydro-9,10-Dihydroxianthracene) for Eucalyptus

Neste trabalho buscou-se converter o processo kraft de produção de celulose de Eucalyptus grandis em processo soda através da adição de 1,4-dihidro-9,10-dihidroxi antraceno (DDA). Além da redução/eliminação da sulfidez, procurou-se diminuir a carga alcalina e o consumo de energia sem prejudicar as características do processo e a qualidade da celulose. Na etapa de otimização da dosagem de DDA pôde-se concluir que 0,04% de DDA é a dosagem que apresenta os melhores resultados tanto para o processo como para as características da celulose; com esta dosagem foi possível reduzir a carga alcalina de 14 para 13% (cerca de 7%). Fixados os níveis de DDA e álcali ativo, obteve-se uma redução do fator H da ordem de 20% sem comprometer a qualidade da celulose e as características do processo. Na última etapa do trabalho foi avaliado o efeito da sulfidez em cozimentos de Eucalyptus grandis com 0,04% de DDA, álcali ativo de 13% e fator H de 522. Nesta etapa observou-se que a sulfidez apresenta efeitos benéficos, principalmente sobre a viscosidade; no entanto, o nível de sulfidez ideal ficou entre 5 e 10%. O DDA apresentou efeito bastante pronunciado em cozimentos soda e lcraft de Eucalyptus grandis, permitindo reduzir a carga de reagentes (especialmente sulfeto de sódio) e consumo de energia sem afetar significativamente a qualidade da celulose ou os parâmetros do processo. A redução da sulfidez representa um grande avanço no sentido de reduzir os impactos ambientais provocados pelas fábricas de celulose kraft.In this research was investigated the possibility of convert the kraft pulping process of Eucalyptus grandis in soda process by the addition of disodium salt of 1,4-dihydro-9,10-dihydroxianthracene (DDA). Besides the reduction/elimination of sulfidity, was looked for the reduction of the alkalinity charge and energy consumption without prejudice the process characteristics and pulp quality. In the stage of determination the best level of DDA was concluded that 0,04% of DDA was the level that showed the best results for the process characteristics and also for the pulp; with this level was possible to reduce alkaline charge from 14 to 13% (approximately 7%). After have fixed the levels of DDA and active alkaly, was reached a reduction in the H factor near to 20% without prejudice the pulp quality and process characteristics. On the last stage of this research was evaluated the effect of sulfidity on Eucalyptus grandis cookings with 0,04% of DDA, active alkaly of 13% and H factor of 522. On this stage was observed that sulfidity have a beneficial effect, specially for the pulp viscosity; however, ideal sulfidity level was between 5 and 10%. DDA shows good effects in soda and kraft pulping process of Eucalyptus grandis allowing the reduction of chemical charge (specially sulfidity) and energy consumption during cooking without damage the pulp quality or process characteristics. The sulfidity reduction represents a great advance in the reduction of the environmental impacts caused by kraft pulp mills

Conversion of the Kraft process in soda-DDA (di-sodium salt of 1,4-Dihydro-9,10-Dihydroxianthracene) for Eucalyptus

Neste trabalho buscou-se converter o processo kraft de produção de celulose de Eucalyptus grandis em processo soda através da adição de 1,4-dihidro-9,10-dihidroxi antraceno (DDA). Além da redução/eliminação da sulfidez, procurou-se diminuir a carga alcalina e o consumo de energia sem prejudicar as características do processo e a qualidade da celulose. Na etapa de otimização da dosagem de DDA pôde-se concluir que 0,04% de DDA é a dosagem que apresenta os melhores resultados tanto para o processo como para as características da celulose; com esta dosagem foi possível reduzir a carga alcalina de 14 para 13% (cerca de 7%). Fixados os níveis de DDA e álcali ativo, obteve-se uma redução do fator H da ordem de 20% sem comprometer a qualidade da celulose e as características do processo. Na última etapa do trabalho foi avaliado o efeito da sulfidez em cozimentos de Eucalyptus grandis com 0,04% de DDA, álcali ativo de 13% e fator H de 522. Nesta etapa observou-se que a sulfidez apresenta efeitos benéficos, principalmente sobre a viscosidade; no entanto, o nível de sulfidez ideal ficou entre 5 e 10%. O DDA apresentou efeito bastante pronunciado em cozimentos soda e lcraft de Eucalyptus grandis, permitindo reduzir a carga de reagentes (especialmente sulfeto de sódio) e consumo de energia sem afetar significativamente a qualidade da celulose ou os parâmetros do processo. A redução da sulfidez representa um grande avanço no sentido de reduzir os impactos ambientais provocados pelas fábricas de celulose kraft.In this research was investigated the possibility of convert the kraft pulping process of Eucalyptus grandis in soda process by the addition of disodium salt of 1,4-dihydro-9,10-dihydroxianthracene (DDA). Besides the reduction/elimination of sulfidity, was looked for the reduction of the alkalinity charge and energy consumption without prejudice the process characteristics and pulp quality. In the stage of determination the best level of DDA was concluded that 0,04% of DDA was the level that showed the best results for the process characteristics and also for the pulp; with this level was possible to reduce alkaline charge from 14 to 13% (approximately 7%). After have fixed the levels of DDA and active alkaly, was reached a reduction in the H factor near to 20% without prejudice the pulp quality and process characteristics. On the last stage of this research was evaluated the effect of sulfidity on Eucalyptus grandis cookings with 0,04% of DDA, active alkaly of 13% and H factor of 522. On this stage was observed that sulfidity have a beneficial effect, specially for the pulp viscosity; however, ideal sulfidity level was between 5 and 10%. DDA shows good effects in soda and kraft pulping process of Eucalyptus grandis allowing the reduction of chemical charge (specially sulfidity) and energy consumption during cooking without damage the pulp quality or process characteristics. The sulfidity reduction represents a great advance in the reduction of the environmental impacts caused by kraft pulp mills

Efeito da antraquinona na curva de cozimento kraft para madeira do híbrido Eucalyptus grandis x Eucalyptus urophylla

O presente estudo teve por objetivo avaliar os efeitos da adição da antraquinona em uma curva de cozimento, com diferentes cargas de reagentes, por meio do processo kraft de polpação, para a madeira de híbrido de Eucalyptus grandis x Eucalyptus urophylla, visando inferir sobre os parâmetros do processo. A madeira foi transformada em cavacos e classificada para condução das curvas de cozimento kraft. As cargas aplicadas foram de 10% a 24% de álcali ativo e 25% de sulfidez, com uma carga de antraquinona de 0,05% (sobre a massa seca de madeira). Avaliou-se o rendimento bruto e depurado, o teor de rejeitos, o número kappa (nível de deslignificação) e o álcali ativo residual. Observou-se que a adição da antraquinona não afetou o rendimento bruto do processo, porém aumentou o rendimento depurado através da redução do teor de rejeitos, em especial para as baixas cargas de álcali ativo (10% e 12%). Outro efeito observado foi a redução do número kappa com a adição da antraquinona, o que indica o aumento da taxa de deslignificação da madeira. Esse aumento é reforçado pelo menor álcali ativo residual, o que se subentende maior aproveitamento dos reagentes no processo

Performance of Schizolobium amazonicum Wood in Bleached Kraft Pulp Production

This study aimed to evaluate the characteristics of Schizolobium amazonicum wood, specifically its performance in bleached kraft pulp production and the characteristics of its pulp. Chips of Schizolobium amazonicum and Eucalyptus grandis x Eucalyptus urophylla (reference) were used. The following parameters were evaluated in the wood: basic density, total extractives, total lignin, holocellulose, and fiber morphology. The pulping simulations were carried out in a laboratory digester, with parameters set to obtain pulp with kappa number 19 ± 0.5. Both pulps were bleached in a PFI mill and submitted to physical-mechanical tests. The results showed that S. amazonicum wood has low basic density and higher content of extractives when compared to E. grandis x E. urophylla wood. For pulping, S. amazonicum required higher alkali charge and H factor to achieve the same delignification level of E. grandis x E. urophylla, resulting in a lower yield, pulp with lower viscosity, and higher wood specific consumption. During bleaching, the brightness gain and final viscosity of S. amazonicum pulp were lower than E. grandis x E. urophylla pulp. Moreover, S. amazonicum pulp had worse physical-mechanical characteristics than E. grandis x E. urophylla

Anatomic characterization of wood from gallery forest in Midwest of Brasil

Foi estudada a anatomia da madeira de 12 espécies ocorrentes em matas ciliares do centro-oeste brasileiro. Para a qualificação de madeiras destinadas à geração de energia, consideram-se a fração parede das fibras e das células parenquimatosas, o percentual das fibras, dos vasos e dos raios, bem como a densidade. Com relação à indicação de madeiras para produção de celulose, tomou-se por base a fração parede, o coeficiente de rigidez, o índice de Runkel, o coeficiente de flexibilidade, os percentuais de elementos constituintes da madeira e a densidade básica. Maprounea guianensis, Micropholis grandifolia, Ocotea coryrnbosa, Ocotea densiflora, Qualea dichotoma, Siphoneugena densiflora e Tabebuia serratifolia, podem ser utilizadas para geração de energia e Nectandra myriantha e Podocarpus brasiliensis podem ser recomendadas para produção de celulose. _________________________________________________________________________________ ABSTRACTWood of 12 species occurring in gallery forest in the Midwest of Brazil were studied. To qualify woods for energy generation, among other parameters, were considered the wall fraction of fibers, parenchymatic cells, vessel elements, percentage of fibers, parenchyma and vessels and the basic density for pulp production. The woods were qualified on the basis of Runkel index, the rigidity and flexibility coefficient and percentage of fibers and basic density. Wood with possibility to be utilized for energy generation are: Maprounea guianensis, Micropholis grandifolia, Ocotea corymbosa, Ocotea densiflora, Qualea dichotoma, Siphoneugena densiflora, Tabebuia serratifolia, and Nectandra myriantha. Nectandra myriantha and Podocarpus brasiliensis are indicated for pulp production