Response of Eucalyptus camaldulensis and Acacia mangium kraft pulp in different ECF bleaching options

Karim, Md. Rezaul; Islam, Nazrul; Malinen, Raimo O.

doi:10.1007/s00226-010-0338-2

Cited by 14 publications

(4 citation statements)

References 7 publications

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“…Também foi menor para a polpa com estágio PO, em razão da alta estabilidade de alvura do peróxido de hidrogênio presente nesse estágio (COLODETTE et al, 2004;EIRAS et al, 2005;ZERONIAN;INGLESBY, 1995), e esse resultado está de acordo com os investigadores Karim et al (2011), trabalho no qual foi verificado que a substituição do estágio D no final da sequência por PO aumenta a estabilidade de alvura, pois o estágio de peróxido pressurizado no final da sequência de branqueamento, possui o poder de estabilizar os grupos carbonílicos na celulose e hemiceluloses, gerados durante o branqueamento. Na Tabela 2, verifica-se que a sequência referência apresentou viscosidade final de 24,2 cP.…”

Section: Resultados E Discussão Branqueamentounclassified

Efeito de reagentes de branqueamento na classificação e refinação de polpa de eucalipto

Favaro

Ventorim

Caraschi

2014

CERNE

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RESUMO:Objetivou-se, neste estudo, avaliar o comportamento do branqueamento de polpa de celulose kraft de eucalipto nas propriedades físicas e mecânicas do papel. A polpa foi branqueada por quatro sequências semelhantes, sendo elas: D(E+P)DD (referência), A HT D(E+P)DD, D(E+P)D(PO), P X (E+P)DD. Cada uma das sequências contendo um dos reagentes analisados: dióxido de cloro, ácido sulfúrico peróxido de hidrogênio pressurizado, e perácido (ácido de Caro). Parte das amostras foi refinada para 40ºSR, enquanto a outra parte foi classificada em equipamento Bauer-McNett. Posteriormente, a porção retida na malha de 50 mesh, foi refinada ao mesmo número de revoluções que sua amostra global. As polpas branqueadas com A HT , P X e PO apresentaram diminuição da resistência mecânica e aumentaram a concentração de polpa em peneiras mais finas, durante a classificação, pois esses reagentes são pouco seletivos. Os resultados encontrados mostraram que polpas branqueadas por reagentes como o perácido e peróxido de hidrogênio pressurizado indicaram menores resistências, assim como suas frações de polpa. No entanto, apesar da baixa seletividade da hidrólise ácida, foi verificado que essa sequência apresentou altos índices de rasgo e tração, tanto da polpa global quanto da polpa classificada, concluindo que as polpas apesar de classificadas, apresentam elevada resistência mecânica. EFFECT OF BLEACHING REAGENTS ON EUCALYPTUS KRAFT PULP FRACTIONATION AND REFINING ABSTRACT:The aim of this study was to evaluate the behavior of eucalyptus kraft pulp bleaching on paper physical and mechanical properties. Pulp was bleached by four similar sequences, each containing one of the reagents analyzed: D(E+P)DD (reference), A HT D(E+P)DD, D(E+P)D(PO), and P X (E+P)DD. Each of the sequences contained one of the studied reagents: chlorine dioxide, sulfuric acid, pressurized hydrogen peroxide, and peracid (Caro's acid). One part of the samples was refined to 40ºSR, whereas the other part was classified in a Bauer-McNett. Subsequently, the part retained in 50 mesh sieve, was refined to the same number of revolutions as the global sample. Pulp bleached in A HT , PO, and P X exhibited reduced mechanical strength and during fractionating increased the concentration of fibers in finer sieves because these reagents are less selective. The results show that pulp bleached in reagents such as pressurized hydrogen peroxide and peracid indicated reduced strength and produced greater fiber concentrations. However, despite the low selectivity of acid hydrolysis, it was found that this sequence had very high tear and tensile strength comparable to classified and global pulp, concluding that regardless of classification, pulp fractions may have high mechanical strength.

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Section: Resultados E Discussão Branqueamentounclassified

Efeito de reagentes de branqueamento na classificação e refinação de polpa de eucalipto

Favaro

Ventorim

Caraschi

2014

CERNE

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“…This is because aromatic ring opening produces water-soluble di-carboxylic acids, such as muconic or succinic acid. 11 Chemical charges to different bleaching sequences are presented in Table 1. OCEH bleaching sequence reduces about 40% of net chlorine usage to the reference, CEHH.…”

Section: Results and Disscussionmentioning

confidence: 99%

Assessment of Aox Content in Bleaching Effluent of Eucalyptus Tereticornis Kraft Pulps

Bhatnagar¹

2022

Curr. World Environ

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The research aim is to reduce the organochlorine content in bleach plant effluents by modifying conventional (CEHH) bleaching sequences. Majority of pulp and paper mills generally adopted CEHH or CEH bleaching sequences, using chlorine or chlorinated compounds to remove the color from pulps. Organochlorine compounds are mainly generated from chlorination and alkali extraction stages. The purpose of the study is to substitute elemental chlorine in bleaching with oxygen, chlorine dioxide, or peroxide. Investigations of AOX content of various traditional and innovative ECF bleaching sequences were conducted. In this study, kraft pulps of Eucalyptus tereticornis with kappa numbers of 44.91 and 26.46 and its oxygen-delignified pulps of kappa numbers 21.32 and 13.03 were used. In terms of AOX, various ECF bleaching sequences were compared to the reference sequence (CEHH). AOX value was 4.45, 3.42, 2.27 kg/tp for the pulp bleached adopting OCEH, ODEH, ODEP bleaching sequence and 9.24 kg/tp for the pulp bleached adopting CEHH bleaching sequence for the pulp corresponding to Kappa number 44.91. Similarly, the AOX value was 2.60 , 1.78 1.24 Kg/tp for the pulps bleached adopting the OCEH, ODEH, ODEP bleaching sequence and 5.56 Kg/tp for the pulp bleached adopting the CEHH sequence for the pulp corresponding kappa number 26.46. Due to partial-delignification of oxygen, AOX production was reduced up to 50%.

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“…The sequence presenting the lowest value for the compression index was the sequence A HT D(PO). Sequences using acid hydrolysis and pressurized hydrogen peroxide are known to be more reactive to carbohydrates (Karim et al, 2011). Pulps that were bleached by more aggressive sequences, such as the sequences using the (PO) stage, presented low mechanical properties due to the degradation of the polysaccharides in the pulp (Favaro et al, 2014).…”

Section: Physico-mechanical Test Compression Indexesmentioning

confidence: 99%

A Study of the Physico-Mechanical Properties in Short Bleaching Sequences

Ferraz

Ventorim

2018

Rev. Árvore

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The kraft pulp of Eucalyptus spp. is relatively easy to be bleached. Therefore, studies have been carried out to reduce the number of stages of bleaching in the plant and minimize process costs. The present work aimed to evaluate the use of two short bleaching sequences in the physico-mechanical properties of cellulosic pulp as well as to compare these values to the ones obtained by usual bleaching sequences. The four bleaching sequences were ECF (elemental chlorine free), D0(E+P)D1P, AHTD0(E+P)D1P, and AHTDP and AHTD (PO). For each bleaching sequence the brightness, brightness reversion and total cost of reagents were evaluated. Physical and mechanical analyses were performed according to the methodologies of the Technical Association of the Pulp and Paper Industry (TAPPI, 2002). The AHTD (PO) sequence showed higher brightness, less brightness reversion, lower total cost and better smoothness compared to the reference sequences. However, it had a lower tear index and a lower compression index. The AHTDP sequence did not reach target brightness, however, it presented brightness reversion and lower total cost than the reference sequences. The AHTDP sequences showed high compression and smoothness, but presented a low compression index.

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Response of Eucalyptus camaldulensis and Acacia mangium kraft pulp in different ECF bleaching options

Cited by 14 publications

References 7 publications

Efeito de reagentes de branqueamento na classificação e refinação de polpa de eucalipto

Efeito de reagentes de branqueamento na classificação e refinação de polpa de eucalipto

Assessment of Aox Content in Bleaching Effluent of Eucalyptus Tereticornis Kraft Pulps

A Study of the Physico-Mechanical Properties in Short Bleaching Sequences

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