The Influence of Cold Caustic Extraction on the Purity, Accessibility and Reactivity of Dissolving-Grade Pulp

2017 ◽  
Vol 2 (35) ◽  
pp. 11462-11468 ◽  
Author(s):  
Xiaoli Dou ◽  
Yong Tang
Keyword(s):  
Cold Caustic Extraction

scholarly journals Deposition of xylan isolated from Pennisetum purpureum on fibres of Eucalyptus globulus and characterisation of the composition of the surface xylans by immunolabelling and enzymatic peeling

Holzforschung ◽  
2018 ◽  
Vol 72 (11) ◽  
pp. 915-922 ◽  
Author(s):  
Tarja Tamminen ◽  
Atte Mikkelson ◽  
Matti Siika-aho ◽  
Kristiina Kruus ◽  
Jaakko Pere ◽  
...  
Keyword(s):  
Eucalyptus Globulus ◽  
Potential Method ◽  
Pennisetum Purpureum ◽  
Composition Gradient ◽  
Elephant Grass ◽  
Oxygen Delignification ◽  
High Quality ◽  
Enzymatic Peeling ◽  
Cold Caustic Extraction ◽  
Hydrolysis Of

AbstractAdsorption of xylan on pulp is a potential method to improve its properties, especially refinability for high quality printing and writing (P&W) paper grades. In this study, elephant grass [Pennisetum purpureum(Schumach.)] xylan was used for this purpose. The xylan was extracted using cold caustic extraction (CCE) fromP. purpureumbrown pulp, produced by the Soda-AQ process (kappa 20). Xylan resorption was accomplished during the oxygen delignification phase of eucalypt [Eucalyptus globulus(Labill.)] pulp to avoid problems induced by the colour of the lignin-contaminated deposited xylan. Immunolabelling and enzymatic peeling methodologies were compared for the analysis of the spatial distribution of xylan in the fibre wall. The labelling appeared unevenly as faint and brighter patches on fibre surfaces. Increased labelling of xylan was detected on the samples with precipitatedP. purpureumxylan. The enzymatic peeling method using a total hydrolysis enzyme mixture yielded a composition gradient as a function of time, showing clear xylose (Xyl) enrichment in the very beginning of the reaction, reflecting hydrolysis of fibre surfaces. Pure xylanase and endoglucanase hydrolyses yielded different product patterns and kinetics compared to total hydrolysis, but interpretation of those results in terms of xylan localisation was not straightforward.

Kinetics and mechanism of hemicelluloses removal from cellulosic fibers during the cold caustic extraction process

2017 ◽  
Vol 234 ◽  
pp. 61-66 ◽  
Author(s):  
Jianguo Li ◽  
Huichao Hu ◽  
Hailong Li ◽  
Liulian Huang ◽  
Lihui Chen ◽  
...  
Keyword(s):  
Extraction Process ◽  
Kinetics And Mechanism ◽  
Cellulosic Fibers ◽  
Cold Caustic Extraction

Characterization of dissolving pulp by fibre swelling in dilute cupriethylenediamine (CUEN) solution in a MorFi analyser

Holzforschung ◽  
2016 ◽  
Vol 70 (7) ◽  
pp. 611-617 ◽  
Author(s):  
Benoît Arnoul-Jarriault ◽  
Raphaël Passas ◽  
Dominique Lachenal ◽  
Christine Chirat
Keyword(s):  
Crystalline Form ◽  
Dissolving Pulp ◽  
Kraft Pulps ◽  
Fibre Structure ◽  
Birch Wood ◽  
Eucalyptus Wood ◽  
Cold Caustic Extraction ◽  
Dissolving Pulps ◽  
Viscose Process

Abstract The swelling of dissolving pulps has been investigated by a new method based on the MorfiR analyser, which is measuring the width variation of thousands of fibres in a cupriethylenediamine (CUEN) solution in a few minutes. Pulps from various origins were analysed coming from softwood, birch wood, eucalyptus wood, kraft pulps, sulphite pulps and ECF and TCF bleached pulps, which were modified by several treatments including chemical (cold caustic extraction, hypochlorite) or enzymatic (cellulase) methods. The swelling was much affected by the crystalline form of cellulose and the hemicellulose content but did not depend neither on the cellulose DP nor on the fibre structure (hardwood vs. softwood). The dissolving pulp reactivity in the viscose process was also assessed by swelling in dilute solutions of cupriethylenediamine (CUEN) instead of the Fock’s method.

scholarly journals Enzymatic Fibre Modification During Production of Dissolving Wood Pulp for Regenerated Cellulosic Materials

2021 ◽  
Vol 12 ◽  
Author(s):  
Pedro E. G. Loureiro ◽  
Sonia M. S. Cadete ◽  
Radina Tokin ◽  
Dmitry V. Evtuguin ◽  
Henrik Lund ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Average Molecular Weight ◽  
Wood Pulp ◽  
Kraft Pulping ◽  
Dissolving Pulp ◽  
Raw Material ◽  
Pulp Yield ◽  
Polysaccharide Monooxygenases ◽  
Cold Caustic Extraction ◽  
Cellulosic Fibres

The production of regenerated cellulosic fibres, such as viscose, modal and lyocell, is based mainly on the use of dissolving wood pulp as raw material. Enzymatic processes are an excellent alternative to conventional chemical routes in the production of dissolving pulp, in terms of energy efficiency, reagent consumption and pulp yield. The two main characteristics of a dissolving pulp are the cellulose purity and the molecular weight, both of which can be controlled with the aid of enzymes. A purification process for paper-grade kraft pulp has been proposed, based on the use of xylanases in combination with hot and cold caustic extraction, without the conventional pre-hydrolysis step before kraft pulping. This enzyme aided purification allowed the production of a dissolving pulp that met the specifications for the manufacture of viscose, < 3% xylan, > 92% ISO brightness and 70% Fock’s reactivity. Endoglucanases (EGs) can efficiently reduce the average molecular weight of the cellulose while simultaneously increasing the pulp reactivity for viscose production. It is shown in this study that lytic polysaccharide monooxygenases act synergistically with EGs in the modification of bleached dissolving pulp.

Xylan deposition onto eucalypt pulp fibers during oxygen delignification

Holzforschung ◽  
2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Marcelo Coelho dos Santos Muguet ◽  
Cristiane Pedrazzi ◽  
Jorge Luiz Colodette
Keyword(s):  
Mechanical Properties ◽  
Pulp Mill ◽  
Physical And Mechanical Properties ◽  
Pulp Fibers ◽  
Oxygen Delignification ◽  
Industrial Practice ◽  
Eucalyptus Pulp ◽  
Low Energy Consumption ◽  
Cold Caustic Extraction ◽  
Xylan Content

Abstract A novel alternative was investigated for elevating the xylan content of eucalyptus pulp through xylan deposition in the course of the oxygen delignification stage. The pH in the range of 10–13 was the only variable evaluated, while the other variables were kept constant in a range similar to industrial practice. Xylans were obtained from unbleached and bleached eucalyptus pulps by cold caustic extraction (CCE), giving rise to brown xylan liquor (BXL) and white xylan liquor (WXL), respectively. The liquors were added to a commercial brown pulp during oxygen delignification. The xylan-enriched pulps were subsequently bleached to 90% ISO with the D(EP)D sequence, beaten in a PFI mill and evaluated for their physical and mechanical properties. Xylan deposition occurred at variable degrees depending upon the pH. Pulp bleachability was not impaired by WXL xylan deposition but was slightly negatively affected by BXL xylan. Pulp beatability was improved by both WXL and BXL xylan deposition. The deposited xylan was more stable across bleaching and beating with the WXL xylan than the BXL xylan deposits. At low energy consumption, the deposited xylan improved pulp physical and mechanical properties. Xylan extraction by CCE with subsequent deposition in the oxygen delignification is an interesting technique to manufacture eucalypt pulps of high xylan content. The potential for industrial application is high as no significant modification of current pulp mill installations is needed.

Mathematical Model for Predicting the Dissolution Behaviors of Hemicelluloses During Cold Caustic Extraction Process

AIChE Journal ◽  
2018 ◽  
Vol 65 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Qing-Qing Guan ◽  
Hua-Jing Zhou ◽  
Lin-Cai Peng ◽  
Ke-Li Chen ◽  
Liang He ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Extraction Process ◽  
Cold Caustic Extraction

Hardwood kraft pulp fibre oxidation using acidic hydrogen peroxide

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Axel Martinsson ◽  
Merima Hasani ◽  
Hans Theliander
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Times ◽  
Compositional Analysis ◽  
Accessible Surface Area ◽  
Carbonyl Groups ◽  
Cold Caustic Extraction ◽  
Cross Links ◽  
Acidic Conditions ◽  
Hardwood Pulp ◽  
Accessible Surface

Abstract Gaining insight into the oxidation of hardwood kraft fibres using hydrogen peroxide at mildly acidic conditions was the main aim of this study. The oxidized hardwood pulp had an increased number of carbonyl groups and, when formed into sheets, an enhanced durability in water was seen due to the formation of cross-links, known as hemiacetals. The carbonyl groups formed were found to be mainly ketones with the exception of the case with longer reaction times (60–90 minutes) at 85 °C, where aldehydes were detected. Through compositional analysis it was found that mainly xylan was oxidized, likely due to the higher amount of xylan close to the surface of the fibre wall. The influence of xylan on the oxidation process was investigated using cold caustic extraction (CCE) performed prior to oxidation. When the CCE pulp was oxidized, there was an increased rate of introduced carbonyl groups and degradation was more pronounced. This is likely due to the accessible surface area being increased, caused by the formation of pores when the lower molecular weight xylan was being extracted during CCE.

Mechanical pretreatment improving hemicelluloses removal from cellulosic fibers during cold caustic extraction

2015 ◽  
Vol 192 ◽  
pp. 501-506 ◽  
Author(s):  
Jianguo Li ◽  
Yishan Liu ◽  
Chao Duan ◽  
Hongjie Zhang ◽  
Yonghao Ni
Keyword(s):  
Cellulosic Fibers ◽  
Mechanical Pretreatment ◽  
Cold Caustic Extraction

Addition of corn fiber xylan to eucalyptus and pinus pulp and its effect on pulp bleachability and strength

2018 ◽  
Vol 33 (3) ◽  
pp. 414-419
Author(s):  
Bianca Moreira Barbosa ◽  
Alessandro Guarino Lino ◽  
Bruno de Freitas Homem de Faria ◽  
Alex Ramos de Aguiar ◽  
Fernando José Borges Gomes ◽  
...  
Keyword(s):  
Strength Properties ◽  
Corn Fiber ◽  
Variable Degree ◽  
Oxygen Delignification ◽  
Rational Use ◽  
Cold Caustic Extraction ◽  
Pulp Properties ◽  
The Impact ◽  
Corn Fibers

AbstractCorn fibers are a significant residue of agriculture due to the huge amounts, which has fueled interest in a more rational use of its components, particularly regarding hemicelluloses. The impact of hemicellulose redeposition on printer and writing (P&W) paper grade pulp properties are discussed in this paper. Xylans extracted from corn fibers (16.9 % xylans) by cold caustic extraction (CCE) were added to commercial brown pulps (eucalypt and pine) in the oxygen delignification (O-stage) and further bleached to 90 % ISO brightness. Hemicelluloses deposition occurred at variable degree (up to 7 % on pulp weight). Pulp bleachability was not impaired by xylan deposition for eucalypt and pine pulps. Xylan deposition onto fibers was more efficient in eucalypt pulp than pine. Pulp beatability and strength properties were improved by xylan deposition for P&W paper grades.

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