Jorge Colodette
Federal University of Viçosa, DEF, Faculty Member
- Received Ph.D from State University of New York, Syracuse, USA in 1986. Worked as visiting scientist at Abitibi-Price... moreReceived Ph.D from State University of New York, Syracuse, USA in 1986. Worked as visiting scientist at Abitibi-Price Inc. in Toronto, Canada as visiting professor at North Carolina State University in Raleigh, USA. Worked as Pulpedit
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Résumé/Abstract Three samples of industrial softwood kraft pulp, two made from southern pine and one made from Western Canadian spruce/pine were bleached to 90% ISO brightness with four ECF sequences: OD (EOP) DD, O (DZ)(EOP) DD, O... more
Résumé/Abstract Three samples of industrial softwood kraft pulp, two made from southern pine and one made from Western Canadian spruce/pine were bleached to 90% ISO brightness with four ECF sequences: OD (EOP) DD, O (DZ)(EOP) DD, O (ZD)(EOP) DD ...
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Research Interests: Chip and Kraft Pulping
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Introdução A relação siringil/guaiacil (S/G) é uma importante característica a ser determinada em ligninas de madeira de Eucalyptus destinada à extração de celulose. Sabe-se que madeiras com maior quantidade de unidades siringil na... more
Introdução A relação siringil/guaiacil (S/G) é uma importante característica a ser determinada em ligninas de madeira de Eucalyptus destinada à extração de celulose. Sabe-se que madeiras com maior quantidade de unidades siringil na lignina são mais facilmente deslignificadas. Vários métodos podem ser utilizados para se determinar esta relação, p orém muitos deles apresentam a desvantagem de necessitar de procedimentos demorados de preparo de amostra. Entretanto a pirólise acoplada à cromatografia gasosa e à espectrometria de massas (Pi-CG/EM) tem sido promissoramente empregada para tal fim, apresentado a vantagem de não requerer procedimentos tediosos de preparo de amostra. 1,2 Diante disso, este trabalho teve o objetivo determinar a relação S/G por Pi-CG/EM em clones de Eucalyptus e comparar os resultados com valores de referência obtidos por oxidação alcalina com nitrobenzeno. Resultados e Discussão As determinações das relações S/G foram realizadas em madeiras de seis clones de E...
Introdução A técnica analítica de pirólise acoplada à cromatografia gasosa e à espectrometria de massas (Pi-CG/EM), tem sido utilizada para determinar a relação siringil/guaiacil (S/G), que é uma importante característica a ser... more
Introdução A técnica analítica de pirólise acoplada à cromatografia gasosa e à espectrometria de massas (Pi-CG/EM), tem sido utilizada para determinar a relação siringil/guaiacil (S/G), que é uma importante característica a ser determinada em ligninas de madeira de Eucalyptus destinada à extração de celulose. Esta técnica tem a vantagem de ter procedimentos rápidos com resultados em pouco tempo, comparado as técnicas já existentes na determinação da relação S/G. Na identificação de clones de Eucalyptus com diferente relação S/G, atualmente se emprega análise exploratória por Análise das Componentes Principais (ACP). Em determinadas situações, o volume de dados gerado é grande, e a utilização de métodos quimiométricos de reconhecimento de padrões pode facilitar a interpretação e a extração de informações úteis dos resultados obtidos. Neste trabalho o nosso objetivo foi identificar a similaridade dos clones, utilizando a área relativa dos cromatogramas de marcadores. Resultados e Disc...
In this study an alternative technique is presented and discussed for measuring yield loss based on the analysis of total organic carbon (TOC) in bleaching filtrates. Oxygen predelignified eucalyptus kraft pulp was subjected to the... more
In this study an alternative technique is presented and discussed for measuring yield loss based on the analysis of total organic carbon (TOC) in bleaching filtrates. Oxygen predelignified eucalyptus kraft pulp was subjected to the DHT(EP)D, D(EP)DD and D(EP)DP bleaching sequences and the gravimetric yield of each stage was determined, with 10 replicates. Then the filtrates were analyzed for TOC and COD. Correlations were established among the three measurement methods (gravimetric, COD and TOC). Yield losses in the DHT stage were more accentuated than in the D0 stage, these losses being recovered in subsequent stages of the bleaching sequence. Yield loss decreased with each advancing stage of the bleaching sequences (D0,DHT>(EP)>D1>P>D2). Yield loss increased with higher kappa factors in the first bleaching stage and with higher temperature in the (EP) stage. The final P stage resulted in greater yield losses than the final D stage. Yield loss intensifies with gain in b...
Bleached eucalyptus kraft pulps are largely used for manufacturing tissue and print & writing (P&W) paper grades and may also be used in mixtures with softwood pulp to improve their strength properties aiming at packaging applications... more
Bleached eucalyptus kraft pulps are largely used for manufacturing tissue and print & writing (P&W) paper grades and may also be used in mixtures with softwood pulp to improve their strength properties aiming at packaging applications such as multilayer cardboard. The final brightness (90 % ISO) and brightness stability (<2% ISO) are rather significant for P&W for it affects optical brighteners demand during paper manufacture. Bleaching chemical demand, effluent load & treatability, pulp OX, brightness stability, beatability and strength are important drivers determining bleach plant operation. This study aimed at investigating the feasibility of using hydrogen peroxide in the High Density Tower (HDT), changing the sequence OQD*(OP)D to OQD*(OP)DP. In addition to improving brightness and brightness stability it was determined that adding hydrogen peroxide in the HDT may save up to 1.2 kg/odt ClO 2 and decrease overall bleaching effluent load. INTRODUCTION Eucalyptus wood has beco...
Commercial bamboo chips were evaluated as raw material for dissolving pulp production. The chips were auto-hydrolyzed (AH) and subsequently cooked by the NaOH/AQ process and bleached to full brightness with the O-CCE-D-(EP)-D-P sequence.... more
Commercial bamboo chips were evaluated as raw material for dissolving pulp production. The chips were auto-hydrolyzed (AH) and subsequently cooked by the NaOH/AQ process and bleached to full brightness with the O-CCE-D-(EP)-D-P sequence. The term CCE designates a cold caustic extraction stage. The bamboo chip chemistry (22.4% lignin, 19.5% xylans, 49.3% cellulose, 16.8% total extractives, and 1.5% ash) was apparently unfavorable; however high quality dissolving pulp was produced using the aforementioned technologies, even when compared to results obtained with traditional eucalypt commercial wood chips. The pulp showed high brightness (92.4 % ISO) and α-cellulose content (94.9%). Its contents of hemicelluloses, extractives and ash were within acceptable levels for a dissolving pulp aimed at viscose rayon production. Thus, the bamboo chip furnish investigated can be regarded as a viable raw material for dissolving pulp production.
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Kraft pulps derived from pine species are largely used for high strength paper products. The quality of such pulps hasbeen improved significantly in the last decades through advances in wood quality and adequate choice of pine species.... more
Kraft pulps derived from pine species are largely used for high strength paper products. The quality of such pulps hasbeen improved significantly in the last decades through advances in wood quality and adequate choice of pine species. The quality ofpine fibers can be further improved by incorporating other fibers to them. In fact, the mixture of pine fibers with hardwood fibers iscommon practice around the world. An alternative to further improve the quality of pine fibers is by mixing them with wood fibersproduced by modern techniques. This study evaluated the impact of mixing 10-40% of eucalyptus wood fibers produced by the P-RCAPMP process on the Pinus radiata fiber properties. The pulp mixes were beat in a PFI mill and evaluated for the main physicalproperties. It was observed that the eucalyptus wood fibers improve the bonding capacity of the Pinus radiata fibers. At a given tensilestrength, the properties of tear index and opacity of the pulp mix increase with increasing prop...
Celulose Nipo-Brasileira is one of the largest eucalyptus bleached kraft pulp mills in Brazil. It produces 860,000 tpy in two lines that are equipped with continuous digesters. Line 1 and line 2 produces ECF (Elemental Chlorine Free) pulp... more
Celulose Nipo-Brasileira is one of the largest eucalyptus bleached kraft pulp mills in Brazil. It produces 860,000 tpy in two lines that are equipped with continuous digesters. Line 1 and line 2 produces ECF (Elemental Chlorine Free) pulp with the sequences: Dhot(EOP)D(EP)D and D(EOP)DP, respectively. The mill has an activated sludge effluent treatment plant comprised of two aeration tanks with 20,000 m3 and it is equipped with superficial aerators followed by four secondary clarifiers (two for each reactor). In the last decades, CENIBRA has been optimizing and changing its processes in order to improve environmental performance. Aiming at decreasing effluent volume, COD and AOX loads, the Ahot(EOP)D(PO) sequence has been proposed and evaluated in lab-scale trials, with partial filtrate recycling. This paper proposes a filtrate recycling scheme that reduces bleach plant effluent volume by 9 m3/adt (air dry ton), i.e., about 50% of the total. The filtrate saved is partially diverted ...
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The Suzano Papel e Celulose S/A, located in Suzano-SP, increased its production from 425.000 to 525.000 adt/yr and that resulted in a decrease of the oxygen delignification residence time from 46 to 38 min. Predicted production expansion... more
The Suzano Papel e Celulose S/A, located in Suzano-SP, increased its production from 425.000 to 525.000 adt/yr and that resulted in a decrease of the oxygen delignification residence time from 46 to 38 min. Predicted production expansion to 575.000 adt/yr will further decrease this time to 34 min. This significant reaction time reduction may lead to decrease post O-stage brightness with negative impact on bleaching chemicals demand and effluent load. The main goal of this study was evaluating the influence of introducing a second oxygen stage at Suzano mill. It was observed that decreasing single O-stage reaction time from 46 to 34 min resulted in 5% lower delignification efficiency and 1.4% lower ISO brightness. These losses were more than compensated by increasing reaction temperature from 98 ºC to 105 ºC, without any perceptive effect on pulp quality. The intensive use of oxygen in the double O-stage process caused a decrease of 0.86 kg/adt of ClO 2 for pulp bleaching to 90% ISO ...
Heat treatment can change wood color without any use of environmentally harmful chemicals, and the efficiency of this process depends on the raw material to be treated. The objective of this study was to evaluate the influence of... more
Heat treatment can change wood color without any use of environmentally harmful chemicals, and the efficiency of this process depends on the raw material to be treated. The objective of this study was to evaluate the influence of extractives on the color change of Eucalyptus pellita and Pinus radiata wood during heat treatment. The extractives were extracted in cold water and in dichloromethane as well as totally removed and the wood was treated at 170°C and 200°C for three hours under atmospheric pressure and in presence of air for evaluating the lightness (L*), green-red coordinate (a*), blue-yellow coordinate (b*), color saturation (C) and tonality angle (H) values. Pinus radiata wood was more resistant to discoloration by heat treatment. The removal of total and cold water-soluble extractives before heat treatment changed the L* value of Pinus radiata, a* value of Eucalyptus pellita, and b*, C, and H values of both species. Removal of extractives soluble in dichloromethane did not affect the color of heat treated wood. Thus, understanding the influence of extractives on heat treated wood can allow adapting the raw material to the process for enhancing the applicability of heat treatment for changing wood color.