scholarly journals Structural changes in residual lignin of Eucalyptus urophylla Eucalyptus grandis LH 107 oxygen delignified kraft pulp upon chlorine dioxide bleaching

2011 ◽  
Author(s):  
J. Liu ◽  
X.F. Zhou
Keyword(s):  
Chlorine Dioxide ◽  
Kraft Pulp ◽  
Structural Changes ◽  
Eucalyptus Grandis ◽  
Eucalyptus Urophylla ◽  
Residual Lignin

An improved procedure for isolation of residual lignins from hardwood kraft pulps

Holzforschung ◽  
2004 ◽  
Vol 58 (5) ◽  
pp. 464-472 ◽  
Author(s):  
Ewellyn Augsten Capanema ◽  
Mikhail Yurievich Balakshin ◽  
Chen-Loung Chen
Keyword(s):  
Molecular Mass ◽  
Nitrogen Content ◽  
Mass Distribution ◽  
Kraft Pulp ◽  
Molecular Mass Distribution ◽  
Eucalyptus Grandis ◽  
Kraft Pulps ◽  
Carbohydrate Composition ◽  
Residual Lignin ◽  
Hydrolysis Of

Abstract Residual lignin preparations were isolated from birch, aspen and Eucalyptus grandis kraft pulp by enzymatic hydrolysis of the pulps with cellulase:hemicellulase mixture. Residual lignin preparations were characterized by investigation of nitrogen content, carbohydrate composition and molecular mass distribution. The use of enzyme with high activity and optimization of enzyme charge resulted in significant decrease in protein contaminants in residual lignin preparations as compared to previously published results. A second order law correlation between enzyme mass charge and nitrogen content in birch residual lignin preparations indicates a strong effect of enzyme charge on the amount of protein contaminants. However, the enzyme charge in the range studied does not appreciably affect either the yields of the residual lignin preparations or percentage and composition of carbohydrates in these preparations. The optimal enzyme charge was highest for Eucalyptus grandis pulp and lowest for birch pulp. It has been suggested that a significant part of the hardwood residual lignin in pulps, especially in E. grandis pulp, consists of low molecular mass lignin fragments bonded to pulp carbohydrates. Higher amount of glucose in E. grandis residual lignin preparation compared to those from birch and aspen implied a higher frequency of lignin-cellulose bonds in eucalypt pulp. Different fractions of birch residual lignin have rather similar molecular mass distribution, which was not affected by the charge of the enzyme. Eucalypt residual lignin preparation had higher molecular mass than birch residual lignin.

Oxidized Derivatives of Lipophilic Extractives Formed during Hardwood Kraft Pulp Bleaching

Holzforschung ◽  
2003 ◽  
Vol 57 (5) ◽  
pp. 503-512 ◽  
Author(s):  
C. S. R. Freire ◽  
A. J. D. Silvestre ◽  
C. Pascoal Neto
Keyword(s):  
Hydrogen Peroxide ◽  
Chlorine Dioxide ◽  
Kraft Pulp ◽  
Structural Changes ◽  
Oxidation Products ◽  
Pulp Bleaching ◽  
Peroxide Bleaching ◽  
Kraft Pulp Bleaching ◽  
First Time ◽  
Derivatives Of

Summary The structural changes of E. globulus wood extractives during bleaching with chlorine dioxide (D), oxygen (O), ozone (Z) and hydrogen peroxide (P) were studied. The detailed characterisation of the extractive derivatives detected in the partially bleached D, O, P and Z pulps was achieved by performing reactions of pure reference compounds with the different bleaching agents. The results show that the unsaturated sterols and fatty acids are extensively degraded during chlorine dioxide and ozone bleaching and only partially degraded during oxygen and hydrogen peroxide bleaching. The corresponding saturated extractives as well as the long chain aliphatic alcohols and ω-hydroxyfatty acids were stable during bleaching. The main oxidation products of β-sitosterol and oleic and linoleic acids, including one chlorinated derivative of linoleic acid, were identified here for the first time in E. globulus bleached pulps and bleaching filtrates.

Application of pure, thermostable, alkali-tolerant xylanase in bleaching of oxygen-delignified pine kraft pulp

TAPPI Journal ◽  
2015 ◽  
Vol 14 (11) ◽  
pp. 689-694
Author(s):  
QINGZHI MA ◽  
QI WANG ◽  
CHU WANG ◽  
NIANJIE FENG ◽  
HUAMIN ZHAI
Keyword(s):  
Intrinsic Viscosity ◽  
Chlorine Dioxide ◽  
High Purity ◽  
Kraft Pulp ◽  
Alkaline Media ◽  
Industrial Scale ◽  
Elemental Chlorine ◽  
Effect Of Oxygen ◽  
Alkaline Tolerant ◽  
Ecf Bleaching

The effect of oxygen (O2)-delignified pine kraft pulp pretreatment by high-purity, thermostable, and alkaline-tolerant xylanases on elemental chlorine free (ECF) bleaching of O2-delignification kraft pulp was studied. The study found that xylanase pretreatment preserved the intrinsic viscosity and yield of O2-delignified pulp while causing about 7% of delignification with high delignification selectivity. The xylanases with high purity, higher thermostability (75°C~80°C) in highly alkaline media (pH 8.0~9.5) could be applied on an industrial scale. Pulp pretreatment by the high-purity, thermostable, and alkaline tolerant xylanases could improve pulp brightness or reduce the chlorine dioxide (ClO2) consumption. In a D0ED1D2 bleaching sequence using the same amount of ClO2, the xylanase-pretreated pulp obtained a higher brightness (88.2% vs. 89.7% ISO) at the enzyme dose of 2 U/g pulp; or for the same brightness as control (88.2% ISO), the ClO2 dosage in the D0 stage was reduced by 27%, which represents a 16% savings in total ClO2 used for bleaching.

Optimization of elemental chlorine-free bleaching for a softwood kraft pulp • part 2: economic analysis of chemical and steam consumption

TAPPI Journal ◽  
2010 ◽  
Vol 9 (9) ◽  
pp. 47-53 ◽  
Author(s):  
BRIAN N. BROGDON
Keyword(s):  
Chlorine Dioxide ◽  
Previous Investigation ◽  
Kraft Pulp ◽  
Energy Costs ◽  
Alkaline Extraction ◽  
Stage Versus ◽  
Kraft Pulps ◽  
Steam Consumption ◽  
Elemental Chlorine ◽  
Softwood Kraft Pulp

Our previous investigation [1] re-analyzed the data from Basta and co-workers (1992 TAPPI Pulping Conference) to demonstrate how oxidative alkaline extraction can be augmented and how these changes affect chlorine dioxide consumption with elemental chlorine-free (ECF) sequences. The current study manipulates extraction delignification variables to curtail bleaching costs with a conventional U.S. Southern softwood kraft pulp. The economic advantages of ~0.35% to 0.65% H2O2 peroxide reinforcement in a 70°C (EOP)-stage versus 90°C (EO)-stage are predisposed to the brightness targets, to short or long bleach sequences, and to mill energy costs. Minimized bleaching costs are generally realized when a 90°C (EO) is employed in D0(EO)D1 bleaching, whereas a 70°C (EOP) is economically advantageous for D0(EOP)D1E2D2 bleaching. The findings we disclose here help to clarify previous ECF optimization studies of conventional softwood kraft pulps.

scholarly journals Eucalypt Clonal Hybrid Influences the Carbon Amount of Below-Ground Biomass in Oxisol, Brazil

2020 ◽  
Vol 3 (1) ◽  
pp. 53
Author(s):  
Grasiele Dick ◽  
Humberto J. Eufrade-Junior ◽  
Mauro V. Schumacher ◽  
Gileno B. Azevedo ◽  
Saulo P. S. Guerra
Keyword(s):  
Carbon Concentration ◽  
Eucalyptus Grandis ◽  
Eucalyptus Camaldulensis ◽  
Eucalyptus Urophylla ◽  
Ground Biomass ◽  
Homogeneity Of Variances ◽  
Below Ground ◽  
Hybrid Eucalyptus ◽  
Carbon Determination ◽  
Hybrid Clones

The objective of this study was to evaluate whether there is an influence of different clonal hybrids of Eucalyptus urophylla on the carbon concentration and amount in below-ground biomass in trees cultivated in Oxisol, Brazil. Stumps and roots of three different eucalypt hybrid clones, AEC 0144, AEC 0223, and VM01, were selected, weighed immediately after being removed from the ground, and sampled for carbon determination and moisture content at the laboratory. The Shapiro-Wilk and Bartlett tests were used to evaluate data distribution and the homogeneity of variances, respectively. Analysis of variance (ANOVA) complemented by the Scott-Knott test was used to evaluate the effects of specie/hybrid on the below-ground biomass (dry matter) and carbon amount per stump. The hybrid type of Eucalyptus urophylla does not influence the carbon concentration; however, there is a difference in below-ground biomass production and carbon amount with it being higher for Eucalyptus urophylla × Eucalyptus camaldulensis when compared to the species Eucalyptus urophylla and hybrid Eucalyptus urophylla × Eucalyptus grandis.

scholarly journals EFICIÊNCIA DE ISCAS GRANULADAS À BASE DE SULFLURAMIDA E DE CLORPIRIFÓS NO CONTROLE DE Atta sexdens sexdens(HYMENOPTERA: FORMICIDAE), NO TRÓPICO ÚMIDO.

1996 ◽  
Vol 26 (3) ◽  
pp. 145-150 ◽  
Author(s):  
Adalton Pinheiro da CRUZ ◽  
José Cola ZANUNCIO ◽  
Ronald ZANETTI ◽  
Odilávio Sá GOMES
Keyword(s):  
Eucalyptus Grandis ◽  
Eucalyptus Urophylla ◽  
Atta Sexdens

Este trabalho foi realizado em plantios de eucalipto urograndis (Eucalyptus urophylla χ Eucalyptus grandis)da Jari Celulose S.A., no município de Almeirim, Pará, no período de agosto/94 a janeiro/95. Foi testada a eficiência de uma isca granulada com sulfluramida e de três outras com clorpirifós, em três dosagens cada por metro quadrado de formigueiro, no controle de Atta sexdens sexdens(Hymenoptera: Formicidae). Os resultados foram comparados com os de uma isca à base de dodecacloro (0,45%) a 10 gramas por metro quadrado de formigueiro. A isca granulada com sulfluramida a 6, 8 e 10 gramas por metro quadrado de formigueiro apresentou 77,78%, 100,00% e 88,90% de controle, respectivamente, assemelhando-se à isca a base de dodecacloro que apresentou 100,00% de formigueiros mortos. As outras iscas, em qualquer dosagem, apresentaram eficiência abaixo de 45,00%.

scholarly journals Painéis Compensados Fabricados com Lâminas de Três Espécies de Eucaliptos

2017 ◽  
Vol 24 (0) ◽  
Author(s):  
Sandra Kazmierczak ◽  
Everton Hillig ◽  
Setsuo Iwakiri
Keyword(s):  
Eucalyptus Grandis ◽  
Eucalyptus Urophylla ◽  
Eucalyptus Saligna ◽  
Eucalyptus Dunnii ◽  
E 32

RESUMO O objetivo foi analisar a qualidade de painéis compensados produzidos com lâminas de Eucalyptus saligna, Eucalyptus dunnii e o híbrido Eucalyptus urophylla x Eucalyptus grandis, em diferentes composições de misturas. Foram produzidos painéis com 500 × 500 × 14 mm e sete camadas de lâminas, coladas com fenol-formaldeído (FF), na gramatura de 360 g. m-2 em linha dupla e teores de sólidos de 28% e 32%. A prensagem dos painéis foi realizada a 130 °C, 12 kgf. cm-2 e 15 minutos. Analisaram-se as propriedades massa específica, umidade, absorção d’água, inchamento em espessura, cisalhamento na linha de cola e flexão estática. Os resultados foram comparados aos requisitos do catálogo técnico da ABIMCI e das normas EN 314-2 e DIN 68792. Os painéis de Eucalyptus dunnii apresentaram menores valores de propriedades mecânicas, com tendência de aumento quando em misturas. Os painéis de Eucalyptus saligna e do híbrido Eucalyptus urophylla x Eucalyptus grandis apresentaram bons resultados, tanto puros como em mistura com as outras espécies.

scholarly journals Parâmetros dendrométricos e correlações com propriedades tecnológicas em um híbrido clonal de Eucalyptus urophylla x Eucalyptus grandis

2010 ◽  
Vol 34 (5) ◽  
pp. 947-959 ◽  
Author(s):  
Fabricio Gomes Gonçalves ◽  
José Tarcísio da Silva Oliveira ◽  
Gilson Fernandes da Silva ◽  
Mauro Eloi Nappo ◽  
Mario Tomazelo Filho
Keyword(s):  
Eucalyptus Grandis ◽  
Eucalyptus Urophylla

A qualidade da madeira aparentemente está associada às características dendrométricas, que por sua vez são influenciadas pelas condições de crescimento. Os objetivos deste estudo foram a caracterização dendrométrica e a realização de correlações de Pearson entre alguns parâmetros tecnológicos da madeira do híbrido clonal de Eucalyptus urophylla x Eucalyptus grandis sob três estratos silviculturais. Os dados dendrométricos foram analisados mediante a análise de regressão. Os resultados mostraram que o híbrido apresenta comportamento similar ao das demais madeiras da mesma espécie que cresceram em outras regiões, destacando-se a espessura do alburno no E1 (talhadia simples, 70 meses e com um desbaste), com pouca variação ao longo do fuste. Todas as árvores apresentaram, em geral, baixa conicidade ao longo do fuste e baixo volume de casca entre os estratos. Na correlação de Pearson foram avaliados entre si nove parâmetros dendrométricos, sete físicos e três mecânicos, longitudinalmente em seções de 3 m e na posição medula-casca nas duas primeiras toras. Os coeficientes encontrados demonstram haver fortes correlações entre as propriedades, destacando-se a densidade básica em relação às demais características e o coeficiente de anisotropia, ambas importantes no processo de desdobro e secagem da madeira. Não houve correlações significativas nas contrações lineares e volumétricas ao longo do comprimento do fuste. A variação radial mostrou boas correlações entre todas as propriedades mecânicas avaliadas nas duas primeiras toras. Em contrapartida, as propriedades físicas avaliadas na posição radial não apresentaram correlações significativas.

scholarly journals DENSITOMETRIA DE RAIOS X NA MADEIRA E CARVÃO DE CLONE DEEucalyptus grandis W. Hill ex Maiden X Eucalyptus urophylla S. T. Blake1

2016 ◽  
Vol 40 (1) ◽  
pp. 155-162 ◽  
Author(s):  
Marina Donária Chaves Arantes ◽  
Paulo Fernando Trugilho ◽  
Mario Tomazello Filho ◽  
José Tarcísio Lima ◽  
Graziela Baptista Vidaurre
Keyword(s):  
Eucalyptus Grandis ◽  
Eucalyptus Urophylla

RESUMO O objetivo deste trabalho foi determinar a densidade relativa aparente por meio da técnica de raios X da madeira e do carvão de um clone de Eucalyptus grandis x Eucalyptus urophylla com 6 anos. A amostragem consistiu na retirada de baguetas de 2 cm de diâmetro no DAP, com trado motorizado, em 50 árvores distribuídas em três classes de diâmetro. Após a determinação da densidade relativa aparente das baguetas, pela técnica de densitometria por raios X, as amostras foram carbonizadas em um forno elétrico (mufla) e suas densidades, determinadas pela mesma técnica. Os valores mais altos de densidade aparente da madeira utilizando a técnica de raios X foram encontrados nas classes diamétricas de 14,1 e 11,4 cm. Os valores de densidade relativa aparente nas amostras de carvão tenderam a aumentar no sentido medula-casca em todas as classes diamétricas.

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