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of delignification in kraft pulping process

Delignification an overview ScienceDirect Topics

Another modification of the kraft process is to replace about 20% of the sodium sulfide with sodium sulfite in the sulfide–sulfite process. The sulfite presumably is able to effectively cleave some lignin linkages to improve the pulping process, to give higher yields, increased brightness and strength, and increased fiber flexibility.

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Detailed Modeling of Kraft Pulping Chemistry. Delignification

This work introduces a phenomena-based model for delignification in the kraft pulping process. The solubilization of lignin is described as a set of chemical reactions representing the entire chemistry of lignin degradation as well as dissolution of the degraded lignin. For modeling, reaction mechanisms and reactions kinetics derived mainly from the literature were used. Each reaction was

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Detailed Modeling of Kraft Pulping Chemistry. Delignification

kraft pulping models. With the model, it is possible to determine the structure of the wood components in the fiber and black liquor at any stage of the pulping process. The simulator should work as a tool to help in understanding the kraft pulping process in more detail. MODEL Basic Principles. The overall idea of this work was to use

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Oxygen delignification process pulp paper mill

Jul 28, 2015· Oxygen Delignification is one of the most significant and well proven pulp bleaching process for ECF (elemental chlorine free) and TCF (total chlorine free) bleached pulp production. It is the first stage of the bleaching process; in this case oxygen and alkali are used to eliminate a portion of the residual lignin in the pulp after cooking.

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Effect of Kraft Pulping on Oxygen Delignification

effect of the major Kraft pulping variables on the response of brownstock pulps to medium consistency oxygen delignification. Kraft pulping was performed on mixed Northeastern hardwood chips in a laboratory rocking digester. Kraft pulps of kappa number 16 and 20 mL KMn04 were produced by pulping under a variety of conditions.

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The Problems in Delignification of Dry Wood by Kraft Process

Chips thickness has the most significant impact on delignification process comparing to other monitored characteristics. The reactions of wood constituents during sulfite and kraft pulping and

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The chemical reactions in Kraft pulping process pulp

Jun 30, 2015· Oxygen delignification process → The chemical reactions in Kraft pulping process. Posted on June 30, 2015 by admin. Kraft pulping process is the most used pulping process in the world. In this process lignin goes into the reactions with the cooking liquor chemicals and split into fragment. These fragments dissolved with the solution and wood

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Chemical Reactions in Kraft Pulping

lignin under kraft pulping conditions. O Karlsson, U Westermark, NP&P Research J. No. 3, vol. 12,1997 5. Degradation of Residual Lignin in Kraft Pulp with Ozone application to Bleaching. D. Lachenal, M. Mauguet. 6 th ISWPC, 1991. 6. A new mechanism for pulp delignification during Chlorination NI.Y. ; Copywrite; K.Lindedahl/2008

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Effect of hardwoods characteristics on kraft pulping

Full Article. Effect of Hardwoods Characteristics on Kraft Pulping Process: emphasis on lignin structure. Ricardo B. Santos, a Ewellyn A. Capanema, b Mikhail Yu. Balakshin, b Hou-Min Chang, a, * and Hasan Jameel a In an attempt to explain variations in delignification behaviors among different hardwood species, the kraft pulping delignification rates of Eucalyptus urograndis, E. nitens, E

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Detailed Modeling of Kraft Pulping Chemistry. Delignification

kraft pulping models. With the model, it is possible to determine the structure of the wood components in the fiber and black liquor at any stage of the pulping process. The simulator should work as a tool to help in understanding the kraft pulping process in more detail. MODEL Basic Principles. The overall idea of this work was to use

More

Effect of Kraft Pulping on Oxygen Delignification

effect of the major Kraft pulping variables on the response of brownstock pulps to medium consistency oxygen delignification. Kraft pulping was performed on mixed Northeastern hardwood chips in a laboratory rocking digester. Kraft pulps of kappa number 16 and 20 mL KMn04 were produced by pulping under a variety of conditions.

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Delignification of Wood and Kraft Pulp with

DELIGNIFICATION OF MIXED NORTHERN PINE KRAFT PULP A sample of never-dried, mixed northern pine kraft pulp (Kappa no. 33, vis-cosity 38 mPa•s) was pretreated with dilute sulphuric acid to remove transition metals, washed, and then treated with a 3.8% per-oxymonophosphoric acid solution at room temperature and a 12:1 liquor to wood ratio for 24 h.

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Towards Online Characterization of Oxygen Delignification

Towards Online Characterization of Oxygen Delignification in Kraft Pulping Mika Liukkonen University of Eastern Finland, Dept. Environmental Science, P.O. Box 1627, FIN-70211 Kuopio, Finland approach is demonstrated in an oxygen delignification process, which is an important stage of chemical pulping

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Effect of oxygen delignification process on the lignin

In the kraft pulping process, the increase of alkali active causes a decrease in lignin levels. In the next process, oxygen delignification shows that longer reaction time causes a decrease in the levels of lignin, COD, and BOD 5 . The information from this study will be helpful to the future implementation of kraft pulping integrated with

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DELIGNIFICATION OF WOOD AND KRAFT PULP WITH

DELIGNIFICATION OF SOUTHERN PINE KRAFT LINERBOARD PULP A quantity of southern pine kraft linerboard pulp with a Kappa number of 65 (9.7% lignin) was obtained from a pulp mill in Arkansas. Using the data of Parsad et al.,5 its yield was estimated to be 55%. Initially the pulp was delignified with the POM Na 5[SiVW 11O 40] using a tungstate buffer.

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Modeling of a modified kraft process ResearchGate

A pseudo-dynamic (mathematical) model for delignification in the kraft pulping process has been developed for Pinus casiawood chips of Manipur forests, based on thirty-six laboratory experiments

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Kraft process Wikipedia

The kraft process (also known as kraft pulping or sulfate process) is a process for conversion of wood into wood pulp, which consists of almost pure cellulose fibers, the main component of paper.The kraft process entails treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na 2 S), known as white liquor, that breaks the bonds that link lignin

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The chemical reactions in Kraft pulping process pulp

Jun 30, 2015· Oxygen delignification process → The chemical reactions in Kraft pulping process. Posted on June 30, 2015 by admin. Kraft pulping process is the most used pulping process in the world. In this process lignin goes into the reactions with the cooking liquor chemicals and split into fragment. These fragments dissolved with the solution and wood

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Kraft Pulping Process Model Derived from Relationship of

Kraft Pulping Process Model Derived from Relationship of the Residual Alkali Concentration on Cooking Time or H-Factor, 1994 Pulping Conference Proceedings V. Masura Consumption of active alkali was studied during initial, bulk and residual phases of kraft delignification of spruce wood.

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(PDF) Rate of Delignification of Eucalypts, an Important

This study investigates the effects on the rate of delignification, HexA content and pulp yield of dissolved wood components (DWC) in the cooking liquor during the kraft pulping of Eucalyptus

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Detailed modeling of the kraft pulping chemistry

Apr 23, 2020· 1 INTRODUCTION. Currently, the kraft pulping process is globally the most common pulping process. The popularity of this process can be explained by high strength properties of the pulp, relatively easy recovery of the cooking chemicals and the use of dissolved organic material for energy production. 1 On the other hand, disadvantages of kraft pulping process include the dark

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Detailed modeling of the kraft pulping chemistry

Currently, the kraft pulping process is globally the most common pul-ping process. The popularity of this process can be explained by high called white liquor. During delignification, the white liquor interacts with the wood, resulting in the formation of black liquor, which is a

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[PDF] Multifunctional alkaline pulping, delignification

In this study, multifunctional alkaline pulping was suggested to produce different pulp grades at one mill site, ranging from high-yield paper pulp to high-purity dissolving pulp. In all process modifications, sulfur was successfully replaced by anthraquinone. Autohydrolysis and alkaline pre-extraction were applied to Eucalyptus globulus wood chips, followed by kraft and soda-AQ pulping.

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