Black liquor gasification combined cycle with CO2 capture-Technical and economic analysis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Diabetes triggers the loss of tooth structure associated to radiographical and histological dental changes and its evolution to progressive pulp and periapical lesions in rats

The aim of this study was to evaluate the putative influence of diabetes without metabolic control in the loss of tooth structure as well as histological changes in dentin and pulp tissue in rats. Diabetes was induced in Wistar rats (n=25) by intravenous administration of alloxan (42mg/kg). Diabetic and non-diabetic control rats were evaluated at 1, 3, 6, 9 and 12 months of follow-up. In order to evaluate the presence and progression of dental caries and periapical lesions, hemimandibles were removed and submitted to radiographical, histological, and morphometrical procedures. Dental caries were detected after radiographical and histological evaluations in diabetic group from the third month of diabetes onset, increasing gradually in frequency and severity in periods. Diabetic rats dental pulps also presented significant reduction in volume density of collagen fibers and fibroblasts at third month, parallel with a trend towards the increase in inflammatory cells volume density. Diabetic rats presented a generalized pulp tissue necrosis after 6 months of diabetes induction. Moreover, periapical lesions were not detected in control group, while these lesions were observed in all rats after 3, 6, 9, and 12 months of diabetes induction. Uncontrolled diabetes seems to trigger the loss of tooth structure, associated to histological dental changes and mediates its evolution to progressive severe pulp and periapical lesions in rats. Therefore, diabetes may be considered a very important risk factor regarding alterations in dental pulp, development of dental caries, and periapical lesions.

Sanitizers effect in mango pulp and peel antioxidant compounds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modificações na produtividade e nas características físicas e químicas da madeira de Eucalyptus grandis causadas pela adubação com lodo de esgoto tratado

O Eucalyptus grandis é uma das espécies mais cultivadas no Brasil devido à sua produtividade e qualidade da madeira. Avaliaram-se o efeito da aplicação de lodo de esgoto tratado (0 a 40 t ha-1 base seca) e uma dose de adubo mineral nos atributos físicos e químicos da madeira de Eucalyptus grandis de árvores com cinco anos de idade, no Município de Itatinga, São Paulo, Brasil. O tipo de solo foi caracterizado como Latossolo Vermelho-Amarelo Distrófico (argila = 120 g kg-1 na camada de 0-20 cm) e o clima, como mesotérmico úmido (Cwa), segundo a classificação de Köeppen. O delineamento experimental foi o de blocos ao acaso, com seis tratamentos e quatro repetições. O diâmetro à altura do peito (DAP), a altura das árvores e o volume de madeira foram obtidos em todas as parcelas de oito árvores com DAP na classe de maior freqüência. As caracterizações físicas e químicas da madeira foram realizadas de acordo com as normas da ABTCP, TAPPI e ABNT. O lodo de esgoto diminuiu a densidade básica da madeira, mas não afetou os teores de celulose, lignina, extrativos e o poder calorífico da madeira. O decréscimo de densidade da madeira pela adubação com lodo de esgoto foi compensado pela maior produtividade de madeira.

Lodo de esgoto na recuperação de áreas degradadas: efeito nas características físicas do solo

A recuperação de áreas degradadas é um processo lento e requer a adição de resíduos orgânicos como condicionador das propriedades físicas do solo. O lodo de esgoto apresenta elevados teores de matéria orgânica (MO) e nutrientes e, portanto, tem alto potencial para utilização nessas áreas. O objetivo deste trabalho foi verificar o efeito da adição de lodo de esgoto na recuperação das características físicas de um solo degradado (Neossolo Quartzarênico) plantado com espécies nativas da Mata Atlântica, na Fazenda Entre-Rios, pertencente à Cia. Suzano Bahia Sul de Papel e Celulose, na região de Itatinga-SP. O experimento foi conduzido em blocos casualizados com quatro repetições. Os tratamentos foram constituídos por seis doses de lodo de esgoto (0, 2,5, 5, 10, 15 e 20 t ha-1), mais um que recebeu a adubação química. A aplicação de lodo de esgoto, para recuperação de áreas degradadas, aumentou os agregados do solo conforme o aumento das doses de lodo, até 12 meses após sua aplicação. As porosidades (macro, micro e total) do solo foram aumentadas com as maiores doses de lodo de esgoto até seis meses após sua aplicação; apenas a microporosidade foi aumentada até 12 meses após a aplicação. Houve aumento da umidade do solo em função do aumento das doses de lodo no solo até seis meses após a aplicação.

Agro-Based Biocomposites for Industrial Applications

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Thermoeconomic functional analysis applied in cogeneration systems associated to cellulose plants

Thermoeconomic Functional Analysis is a method developed for the analysis and optimal design of improvement of thermal systems (Frangopoulos, 1984). The purpose of this work is to discuss the cogeneration system optimization using a condensing steam turbine with two extractions. This cogeneration system is a rational alternative in pulp and paper plants in regard to the Brazilian conditions. The objective of this optimization consists of minimizing the global cost of the system acquisition and operation, based on the parametrization of actual data from a cellulose plant with a daily production of 1000 tons. Among the several possible decision variables, the pressure and temperature of live steam were selected. These variables significantly affect the energy performance of the cogeneration system. The conditions which determine a lower cost for the system are presented in conclusion.

Cogeneration system design optimization

Cogeneration system design deals with several parameters in the synthesis phase, where not only a thermal cycle must be indicated but the general arrangement, type, capacity and number of machines need to be defined. This problem is not trivial because many parameters are considered as goals in the project. An optimization technique that considers costs and revenues, reliability, pollutant emissions and exergetic efficiency as goals to be reached in the synthesis phase of a cogeneration system design process is presented. A discussion of appropriated values and the results for a pulp and paper plant integration to a cogeneration system are shown in order to illustrate the proposed methodology.

Cogeneration system design optimization

Cogeneration system design deals with several parameters in the synthesis phase, where not only a thermal cycle must be indicated but the general arrangement, type, capacity and number of machines need to be defined. This problem is not trivial because many parameters are considered as goals in the project. An optimization technique that considers costs and revenues, reliability, pollutant emissions and exergetic efficiency as goals to be reached in the synthesis phase of a cogeneration system design process is presented. A discussion of appropriated values and the results for a pulp and paper plant integration to a cogeneration system are shown in order to illustrate the proposed methodology.

A compostagem como processo catalisador para a reutilização dos resídues de fábrica de celulose e papel

Recognizing the great potential of this residue to increase the eucalyptus forests produtivity - when used in its humidified form - the main objective of this project was to decompose the solid residues generated at Luiz Antonio mill, in a fast and artificial way, by means of piles or ridges of composted materials. The materials used in this composting process were: activated sludge, dregs and grits, wood ash and biomass. Applications of both phosphorus and potassium have been used during the planting phase. Nitrogen, in the form of urea, has been applied in two treatments with the main purpose to decrease the C/N ratio and to speed up the decomposition process. The experiment was carried out in 120 days. The best results were obtained in residue piles with a 3:1 ratio, i.e., 75% residues + 25% biomass. This mixture provided an extremely good aeration, thus enabling an appropriate material mixing and homogenization. Under the technological viewpoint, the results obtained from the composting process were quite satisfactory for VCP industrial residues treatment. This composting process enabled a material accelerated stabilization (lower C/N ratio) and homogenization. After this experiment, it became possible to use all residues just as they were generated by Luiz Antônio pulp and paper mill. This project is of the utmost relevance to VCP's forestry department as far as a significant amount of nutrients is getting back to the soil in the form of mineral and organic materials.

Desenvolvimentos da biopolpação no Brasil

Biopulping is a technology which application can be advantageous to mechanical or chemical pulping. It presents benefits such as the creation of stronger pulp, as well as energy or chemicals savings. This paper gives an overview of the recent efforts to develop biopulping processes in Brazil as well as provides critical information on biopulping development worldwide. Eucalyptus grandis wood chips have been biotreated by Ceriporiopsis subvermispora in a 50-ton biopulping pilot-plant and used to produce TMP and CTMP pulps on a mill scale, Up to 18% and 27% energy savings have been observed for producing 450-470 CSFreeness TMP and CTMP pulps. Despite darker bio-TMP pulps are produced, one-stage bleaching with 5% H2O2 was sufficient to improve brightness values to 70% and 72% for bio-TMP and control pulps, respectively. Understanding biopulping mechanisms is also relevant because more resistant and competitive fungal species could be selected with basis on a function-directed screen-ing project. As far as the chemical changes induced by the fungus in wood are concerned, recent efforts have pointed out for two different types of wood transformations. One of them involves intense lignin depolymerization in short biotreatment periods, while the other indicates that esterification reactions of oxalate secreted by the Jungas on the polysaccharides chains increase the water saturation point of the fibers. Both transformations are expected to affect the fiber-fiber bonding and, consequently, the physical resistance of wood.

Análise do setor de celulose e papel na era da globalização: um olhar sobre sua produção e mão-de-obra

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aproveitamento de resíduos da indústria de celulose e papel em argamassa mista de revestimento interno

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Isolamento e seleção de micro-organismos produtores de xilanase

Pós-graduação em Agronomia - FEIS

Análise de sistemas de cogeração com gaseificação de licor negro no setor de papel e celulose

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)