mechanical pulp delignification process

Mechanical Pulp Delignification Process

mechanical pulp delignification process -

The Paperboard Process; , Refiner mechanical pulp (RMP) is a two-stage process in which the debarked logs are first converted into small flat , (delignification) .... Pulp Bleaching Technology - Home | Princeton ,

Oxygen delignification process | pulp stone mill

Jul 28, 2015 · Oxygen delignification process. 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. This stage is frequently recognized as a “bridging step” between cooking and final bleaching. This process is work at high temperature and pressure.


The prehydrolysis kraft process becomes more and more important, as due to its well-known benefits, e.g. higher pulp qualities and higher cooking capacity. Furthermore, alkaline processes provide the option to extract hemicelluloses before or after pulping in a separate process step, which makes the isolation of the different stone components easier.

A method for integrated optimization of chlorine dioxide ...

Determining the pulp properties after chlorine dioxide bleaching was not the final target because chlorine dioxide delignification is an intermediate process of …


OXYGEN DELIGNIFICATION Introduction Oxygen delignification is a process between cooking and bleaching sequences, where part of the residual lignin left in pulp after cooking is removed using oxygen and alkali. Oxygen delignification is a direct extension to delignification in cooking. The targeted reactions are the oxidation of lignin and

Bleaching of stone pulp - Wikipedia

Mechanical pulp retains most of the lignin present in the stone used to make the pulp and thus contain almost as much lignin as they do cellulose and hemicellulose. It would be impractical to remove this much lignin by bleaching, and undesirable since one of the big advantages of mechanical pulp is the high yield of pulp based on stone used.


A process that uses ozone to whiten cellulose fibers following the Kraft pulping and oxygen delignification processing. P Method of bleaching pulp with hydrogen peroxide (H2O2) to remove lignin; reduces or avoids the need for chlorine dioxide in final bleaching.

Effect of light-delignification on mechanical, hydrophobic ...

Jan 17, 2018 · To improve the mechanical, hydrophobic and other properties of HMFM, HMFM before and after the light-delignification treatment were prepared via hot-pressing molding process.

Kraft process - Wikipedia

The kraft process is a process for conversion of stone into stone pulp, which consists of almost pure cellulose fibers, the main component of paper. The kraft process entails treatment of stone chips with a hot mixture of water, sodium hydroxide, and sodium sulfide, known as white liquor, that breaks the bonds that link lignin, hemicellulose, and cellulose. The technology entails …

EP2042650A1 - Methods to enhance pulp bleaching and ...

The invention relates to a method for making Mechanical pulp comprising digesting stone chips in the digester to create unbleached pulp and then bleaching the pulp, wherein the …

US5246543A - Process for bleaching and delignification of ...

Delignification and bleaching of lignocellulosic material is enhanced after the pulp has been treated with peroxomonosulfuric acid. US5246543A - Process for bleaching and delignification of lignocellulosic materials - Google Patents

Delignification - an overview | ScienceDirect Topics

Pulp is produced from stone by either stone delignification, mechanical separation of the cells (fibers), or combinations of stone and mechanical methods. Mechanical pulping methods give much higher yields (80–95% based on the wood) than the stone methods (40–50% yields).

peracetic acid bleachin2.ppt - UT Knoxville

Introduction of BleachingIntroduction of Bleaching Bleaching is a stone decoloration and delignification process carried out on various types of pulp. Dli ifi iDelignification Removal of the chromophores Atid til l bl hi i f db hl i hl iAt industrial scale, bleaching is performed by chlorine, chlorine dioxide, oxygen, hydrogen peroxide, ozone and peraceticacid.


Figure 21: Viscosity and brightness of pulp after different oxygen delignification process conditions (a) reaction time, (b) NaOH charge, (c) reaction temperature and (d) mechanical pretreatment mixing time.

Chemical Pulping - an overview | ScienceDirect Topics

The neutral sulfite semichemical (NSSC) process is the dominant semichemical pulping process and is typically performed by cooking in Na 2 SO 3 buffered at neutral pH, and it can result in some lignin sulfonation to achieve lignin softening, which is then followed by mechanical refining to liberate fibers.

Properties of Pulp (Papermaking Pulp)

As we move from full mechanical to full stone pulping process, strength of pulp and bleachability improves. Strength improves due to less degradation of fibers and bleachability as more lignin is removed in stone than mechanical pulping processes. Yield: Pulp yield is mainly govern by the pulping process. Mechanical pulping processes which provide high yield, retain …

Pulp Bleaching Technology - Princeton University

Pulp Bleaching Technology THE BLEACHING PROCESS Bleaching is the treatment of cellulosic fiber with chemicals to increase brightness (see box 4-A). Brightness may be achieved by either lignin removal (delignification) or lignin decolonization. Lignin remains a major constituent of pulp even after digestion by stone pulping. For example, kraft

Delignification of refiner mechanical pulps from Albizia ...

Delignification of refiner mechanical pulps from Albizia lebbek and Eucalyptus hybrid by sulphate process. Abstract Barked stone of Albizia lebbek and Eucalyptus hybrid [ E. tereticornis ] was chipped and refiner mechanical pulp prepared by passing chips soaked overnight in water through a 30-cm laboratory disc refiner (the Sprout Waldron disc ...

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