RU95114367A - Method of delignifying and bleaching lignin-cellulose pulp - Google Patents

Method of delignifying and bleaching lignin-cellulose pulp

Info

Publication number
RU95114367A
RU95114367A RU95114367/12A RU95114367A RU95114367A RU 95114367 A RU95114367 A RU 95114367A RU 95114367/12 A RU95114367/12 A RU 95114367/12A RU 95114367 A RU95114367 A RU 95114367A RU 95114367 A RU95114367 A RU 95114367A
Authority
RU
Russia
Prior art keywords
pulp
bleaching
degree
whiteness
delignification
Prior art date
Application number
RU95114367/12A
Other languages
Russian (ru)
Other versions
RU2097462C1 (en
Inventor
Линстен Магнус
Se]
Баста Йири
Хелльстрем Анна-Софи
Original Assignee
Ека Нобель Актиеболаг (SE)
Ека Нобель Актиеболаг
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ека Нобель Актиеболаг (SE), Ека Нобель Актиеболаг filed Critical Ека Нобель Актиеболаг (SE)
Priority claimed from PCT/SE1993/001019 external-priority patent/WO1994012721A1/en
Publication of RU95114367A publication Critical patent/RU95114367A/en
Application granted granted Critical
Publication of RU2097462C1 publication Critical patent/RU2097462C1/en

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/10—Bleaching ; Apparatus therefor
    • D21C9/16—Bleaching ; Apparatus therefor with per compounds
    • D21C9/166—Bleaching ; Apparatus therefor with per compounds with peracids
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/10—Bleaching ; Apparatus therefor
    • D21C9/1026—Other features in bleaching processes
    • D21C9/1042—Use of chelating agents
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/10—Bleaching ; Apparatus therefor
    • D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
    • D21C9/153—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications with ozone
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/10—Bleaching ; Apparatus therefor
    • D21C9/16—Bleaching ; Apparatus therefor with per compounds
    • D21C9/163—Bleaching ; Apparatus therefor with per compounds with peroxides

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)

Abstract

FIELD: paper-making industry. SUBSTANCE: pulp is delignified with placid or salt thereof, treated with complexing agent and finally bleached with chlorine-free bleaching agent. Delignification step is carried out with strongly oxidizing peracetic acid, which results in noticeable increase in degree of whiteness and in marked decline in kappa number after bleaching, using chlorine-free bleaching agent. The latter comprises at least one of group consisting of peroxide-containing compound, ozone or sodium dithionite which are used in specific sequence or in mixtures. Pulp viscosity is maintained at comparatively high level, since desired effect of increasing degree of whiteness is extremely selective. It is advisable that both delignification and treating with complexing agent should be carried out at pH close to neutral, thereby minimizing need for pH control and providing possibility of in-plant use of spent bleaching liquor, e.g. in pulp washing. During final bleaching with ozone and hydrogen peroxide, proposed method makes it possible to obtain soft wood pulps with degree of whiteness greater than 90% ISO index, and to remove from pulp practically all lignin, while maintaining sufficient pulp concentration level. EFFECT: higher efficiency.

Claims (1)

Изобретение относится к способу делигнификации и отбеливания лигноцеллюлозосодержащей пульпы, в котором пульпу делигнифицируют перкислотой или ее солью, обрабатывают комплексообразующим агентом и затем отбеливают отбеливателем, не содержащим хлор. Делигнификацию возможно осуществлять сильно окисляющей перуксусной кислотой, что приводит к заметному увеличению степени белизны и заметному уменьшению числа каппа после отбеливания отбеливателем, не содержащим хлора, и включающим по крайней мере одно из пероксидсодержащего соединения, озона или дитионита натрия или по выбору их последовательности или смеси. Эффект, выражающийся в увеличении степени белизны, является чрезвычайно селективным, т.е. вязкость пульпы поддерживают по сравнительно высокой степени. Как делигнификацию, так и обработку комплексообразующим агентом целесообразно осуществлять при pH, близком к нейтральному, что сводит к минимуму необходимость в регулировании pH и предоставляет возможность для внутреннего использования отработанного отбелочного раствора, например, для промывки пульпы. При конечном отбеливании озоном и перекисью водорода посредством предлагаемого способа можно получить пульпы мягкой древесины, имеющие степень белизны, превосходящую 90% ИСО, и удалить из пульпы практически весь лигнин при поддержании достаточной концентрации пульпы.The invention relates to a method for the delignification and bleaching of a lignocellulose-containing pulp, in which the pulp is delignified with peracid or its salt, treated with a complexing agent, and then bleached with chlorine-free bleach. It is possible to carry out delignification with strongly oxidizing peracetic acid, which leads to a noticeable increase in the degree of whiteness and a noticeable decrease in the number of kappa after bleaching with a bleach that does not contain chlorine, and includes at least one of a peroxide-containing compound, ozone, or sodium dithionite or, by choice of their sequence or mixture. The effect of increasing the degree of whiteness is extremely selective, i.e. pulp viscosity is maintained at a relatively high degree. It is advisable to carry out both delignification and treatment with a complexing agent at a pH close to neutral, which minimizes the need for pH adjustment and provides an opportunity for the internal use of spent bleaching solution, for example, for washing pulp. With the final bleaching with ozone and hydrogen peroxide, by means of the proposed method it is possible to obtain softwood pulps having a degree of whiteness exceeding 90% ISO, and to remove almost all lignin from the pulp while maintaining a sufficient concentration of pulp.
RU9595114367A 1992-11-27 1993-11-25 Method of delignification and bleaching of lignocellulose-containing pulp RU2097462C1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
SE9203585A SE500605C2 (en) 1992-11-27 1992-11-27 Delignification of softwood pulps to give high brightness - using peracid, complexant and peroxide, with retention of pulp viscosity and strength
SE9203585-6 1992-11-27
SE9300226-9 1993-01-26
PCT/SE1993/001019 WO1994012721A1 (en) 1992-11-27 1993-11-25 Process for delignification of lignocellulose-containing pulp

Publications (2)

Publication Number Publication Date
RU95114367A true RU95114367A (en) 1996-12-27
RU2097462C1 RU2097462C1 (en) 1997-11-27

Family

ID=20387965

Family Applications (1)

Application Number Title Priority Date Filing Date
RU9595114367A RU2097462C1 (en) 1992-11-27 1993-11-25 Method of delignification and bleaching of lignocellulose-containing pulp

Country Status (3)

Country Link
RU (1) RU2097462C1 (en)
SE (1) SE500605C2 (en)
ZA (1) ZA938748B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI127996B (en) 2016-07-01 2019-07-15 Kemira Oyj A process for treating pulp

Also Published As

Publication number Publication date
ZA938748B (en) 1994-06-30
SE9203585L (en) 1994-05-28
RU2097462C1 (en) 1997-11-27
SE500605C2 (en) 1994-07-25
SE9203585D0 (en) 1992-11-27

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