+

WO1996035015A1 - TRAITEMENT DE PATE A PAPIER AVEC UN AGENT CHELATEUR SUIVI D'UN BLANCHIMENT A UN pH SUPERIEUR A 9 - Google Patents

TRAITEMENT DE PATE A PAPIER AVEC UN AGENT CHELATEUR SUIVI D'UN BLANCHIMENT A UN pH SUPERIEUR A 9 Download PDF

Info

Publication number
WO1996035015A1
WO1996035015A1 PCT/SE1996/000405 SE9600405W WO9635015A1 WO 1996035015 A1 WO1996035015 A1 WO 1996035015A1 SE 9600405 W SE9600405 W SE 9600405W WO 9635015 A1 WO9635015 A1 WO 9635015A1
Authority
WO
WIPO (PCT)
Prior art keywords
pulp
chelating agent
bleaching
hydrogen peroxide
treatment
Prior art date
Application number
PCT/SE1996/000405
Other languages
English (en)
Inventor
Rolf Boman
Ulf GERMGÅRD
Kenneth HAFVENSTRÖM
Jonas Lindquist
Original Assignee
Sunds Defibrator Industries Ab
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 Sunds Defibrator Industries Ab filed Critical Sunds Defibrator Industries Ab
Priority to JP8533220A priority Critical patent/JPH11504399A/ja
Publication of WO1996035015A1 publication Critical patent/WO1996035015A1/fr
Priority to NO975038A priority patent/NO975038L/no
Priority to FI974115A priority patent/FI974115A0/fi

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
    • D21C9/1026—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
    • D21C9/1005—Pretreatment of the pulp, e.g. degassing the pulp
    • 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
    • D21C9/1036—Use of compounds accelerating or improving the efficiency of the processes

Definitions

  • This invention relates to chlorine free bleaching of pulp from lignocellulosic material.
  • the method comprises treat ⁇ ment of the pulp with chelating agent and subsequent bleach ⁇ ing in at least one step with chlorine free bleaching agents .
  • the bleaching sequence usually includes only the chemicals oxygen and hydrogen peroxide.
  • Hydrogen peroxide is a highly effective bleaching chemical when the bleaching conditions are the right ones.
  • brightness levels pf substantially full brightness, i.e. almost 90% ISO have been achieved on mill scale. This presupposes, however, very special con ⁇ ditions, such as that the papermaking pulp is subjected
  • a low metal content in the pulp prior to the hydrogen peroxide step is obtained by treating the pulp with a chelating agent, for example EDTA or DTPA , and there ⁇ after to wash the pulp in order to eliminate the released metal ions before the hydrogen peroxide step.
  • a chelating agent for example EDTA or DTPA
  • This method is described in the patent SE 467 006 (EKA Nobel).
  • the treatment with chelating agent shall be carried out between 10-100°C f° r a period of up to 6 hours at a pH between 3.1 and 9.
  • EKA Nobel has at a later date, a.o.
  • the pulpmaking industry of today manufactures paper ⁇ making pulp mostly by digesting and oxygen bleaching the pulp to a far-reaching degree, whereafter the blea ⁇ ching proper is carried out by using all towers and tanks in the existing plants, so that a very long stay- time in the chelating agent step, and especially in the hydrogen peroxide step, is obtained.
  • the pulp is also washed very accurately between the different bleaching steps. Such washing, however, requires large amounts of water, and therefore it cannot be used if and when the bleach plants must be closed at their effluent, which in most pulp mills will be required in order to meet various environmental obligations.
  • the present invention has the object to solve the aforesaid problems. It implies, that papermaking pulp can be bleached with chlorine free chemicals in an effectively closed system without forming disturbing in- crustrations .
  • the invention is described in greater detail in the following by way of some embodiments thereof.
  • the invention is directed to chlorine free bleaching pf pulp, where pH is held above 9, suitably between 9 and 11.5, during the entire delignification and bleaching process.
  • the chelating agent step (Q-step) is carried out at a considerably higher than normal pH prior to a subsequent peroxide bleaching (P-step).
  • P-step peroxide bleaching
  • chelating agents which are active at a con ⁇ siderably higher pH value than that which normally is used at bleaching according to SE-patent 467 006 (see above).
  • the chelating agent EDTA normally used is a poor chelating agent at alkaline conditions and can . be replaced, for example, by DTPA, which is active evwn at higher pH.
  • Incrustrat- ions normally become a problem difficult solve when the bleach plant is closed, because the concentrations of a.o. calcium, barium, oxalate, carbonate and sul ⁇ phate can increase above the solubility maximum, which results in precipitations to begin to form.
  • some type of initiation of the precipitation process is also required, for example via a pH or temperature change, in order to cause the precipitation to start, but in that case the precipitation can proceed very rapidly.
  • Another advantage is, that the metals and a.o.
  • the transistion metals dangerous for the process i.e. especially manganese, further can be oxidized by adding an oxidation agent, so that their capacity of degrading peroxide is reduced, alter ⁇ natively entirely eliminated.
  • the oxidation of these metals is carried out preferably with oxygen gas and/or hydrogen peroxide at a temperature of above 75 C prior to the bleaching with chlorine free bleaching agents, such as hydrogen peroxide.
  • a suggested suitable sequence comprises: digestion - Q-step - 02 ⁇ delignification - Q-step - P-step.
  • An initiating chelating agent step and an oxygen step thus, can be carried out directly after the digestion. Thereafter the treatment proper with chelating agent is carried out prior to the hydrogen peroxide bleach ⁇ ing.
  • the pH value shall be held above 9, suitably at 9-11, preferably at 9-11.5, through the entire sequence.
  • Both Q-steps can advantageously be carried out in the presence of oxidation agent, preferably oxygen and/or hydrogen peroxide for the oxidation of metals present. The metals become thereby less disturbing for the bleaching.
  • bleachings can be carried out where oxygen and/or peracids can be used.
  • the bleach ⁇ ing preferably is carried out in at least two oxidiz ⁇ ing steps, where hydrogen peroxide and oxygen can be used in the same bleaching step.
  • the charge should be 1-10 kg (100%-product) per ton pulp, preferably 2-5 kg per ton pulp.
  • the invention also implies that an effluent-free pro ⁇ cess can be obtained.
  • the process is preferably closed in such a way, that washing steps are carried out after every treatment step (Q-step and, respectively, bleaching step), and the filtrate from every washing step is recycled as washing liquid in preceding washing steps.
  • a high and uniform pH level being maintained during the entire process, no precipitations of in- crustrations occur, in spite of the closing of the bleaching process.

Landscapes

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

Abstract

Cette invention concerne un procédé de blanchiment sans chlore de pâte à papier constituée de matière ligno-cellulosique, ledit procédé consistant à traiter la pâte avec un agent chélateur et à procéder ensuite à son blanchiment, en au moins une étape, avec des agents de blanchiment ne contenant pas de chlore. Conformément à ce procédé, le PH est maintenu à une valeur supérieure à 9 lors de l'étape de traitement par l'agent chélateur et au cours des étapes ultérieures de blanchiment.
PCT/SE1996/000405 1995-05-02 1996-03-27 TRAITEMENT DE PATE A PAPIER AVEC UN AGENT CHELATEUR SUIVI D'UN BLANCHIMENT A UN pH SUPERIEUR A 9 WO1996035015A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP8533220A JPH11504399A (ja) 1995-05-02 1996-03-27 キレート化剤でのパルプの処理およびそれに続く９より高いｐＨ値での漂白
NO975038A NO975038L (no) 1995-05-02 1997-10-31 Behandling av masse med chelateringsmiddel og påfölgende bleking ved en pH-verdi over 9
FI974115A FI974115A0 (fi) 1995-05-02 1997-11-03 Massan käsittely kelatointiaineella ja seuraava valkaisu pH-arvossa yli 9

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9501623-4 1995-05-02
SE9501623A SE9501623L (sv) 1995-05-02 1995-05-02 Blekning av massa

Publications (1)

Publication Number Publication Date
WO1996035015A1 true WO1996035015A1 (fr) 1996-11-07

Family

ID=20398166

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1996/000405 WO1996035015A1 (fr) 1995-05-02 1996-03-27 TRAITEMENT DE PATE A PAPIER AVEC UN AGENT CHELATEUR SUIVI D'UN BLANCHIMENT A UN pH SUPERIEUR A 9

Country Status (6)

Country Link
JP (1) JPH11504399A (fr)
CA (1) CA2219767A1 (fr)
FI (1) FI974115A0 (fr)
NO (1) NO975038L (fr)
SE (1) SE9501623L (fr)
WO (1) WO1996035015A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998051855A1 (fr) * 1997-05-14 1998-11-19 Mo Och Domsjö Aktiebolag Procede de reduction des problemes lies au tartre dans la production de pate a papier blanchie, a l'aide d'un circuit ferme de liquide de lavage
WO1999027178A1 (fr) * 1997-11-25 1999-06-03 Amylum Belgium N.V. Perfectionnements apportes au procede de blanchiment de la pate chimique et dispersions intermediaires de pate
WO1999046441A1 (fr) * 1998-03-10 1999-09-16 Solvay (Societe Anonyme) Procede de blanchiment et/ou de delignification de pates a papier

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1994012721A1 (fr) * 1992-11-27 1994-06-09 Eka Nobel Ab Procede de delignification de pulpe contenant de la cellulose ligneuse
WO1995009944A1 (fr) * 1993-10-01 1995-04-13 Union Camp Patent Holding, Inc. REDUCTION DES DEPOTS PAR REGULATION DU pH ET DE LA CONCENTRATION DE SELS

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1994012721A1 (fr) * 1992-11-27 1994-06-09 Eka Nobel Ab Procede de delignification de pulpe contenant de la cellulose ligneuse
WO1995009944A1 (fr) * 1993-10-01 1995-04-13 Union Camp Patent Holding, Inc. REDUCTION DES DEPOTS PAR REGULATION DU pH ET DE LA CONCENTRATION DE SELS

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998051855A1 (fr) * 1997-05-14 1998-11-19 Mo Och Domsjö Aktiebolag Procede de reduction des problemes lies au tartre dans la production de pate a papier blanchie, a l'aide d'un circuit ferme de liquide de lavage
WO1999027178A1 (fr) * 1997-11-25 1999-06-03 Amylum Belgium N.V. Perfectionnements apportes au procede de blanchiment de la pate chimique et dispersions intermediaires de pate
WO1999046441A1 (fr) * 1998-03-10 1999-09-16 Solvay (Societe Anonyme) Procede de blanchiment et/ou de delignification de pates a papier
BE1011785A3 (fr) * 1998-03-10 2000-01-11 Solvay Procede de blanchiment et/ou de delignification de pates a papier chimiques.

Also Published As

Publication number Publication date
SE9501623D0 (sv) 1995-05-02
NO975038D0 (no) 1997-10-31
FI974115L (fi) 1997-11-03
NO975038L (no) 1997-10-31
FI974115A0 (fi) 1997-11-03
JPH11504399A (ja) 1999-04-20
CA2219767A1 (fr) 1996-11-07
SE9501623L (sv) 1996-11-03

Similar Documents

Publication Publication Date Title
CA1190360A (fr) Delignification catalytique par un peroxyde en milieu alcalin
JP4499280B2 (ja) 過酸による化学パルプの漂白
US5785812A (en) Process for treating oxygen delignified pulp using an organic peracid or salt, complexing agent and peroxide bleach sequence
US5658429A (en) Process for bleaching of lignocellulose-containing pulp using a chelating agent prior to a peroxide-ozone-peroxide sequence
WO1979000637A1 (fr) Blanchiment de materiau lignocellulosique avec des agents de blanchiment contenant du peroxyde
US6007678A (en) Process for delignification of lignocellulose-containing pulp with an organic peracid or salts thereof
WO1996012063A1 (fr) Procede d'elimination de groupes d'acide hexenuronique dans de la pate de cellulose par traitement thermique
WO1996009434A1 (fr) Procede de blanchiment de pate kraft
EP0789798B1 (fr) Procede de delignification et de blanchiment de cellulose chimique
EP0464110B1 (fr) Procede de blanchiment servant a la production de pulpes tres claires
CA2647781C (fr) Procede de blanchiment de pate chimique
WO1996035015A1 (fr) TRAITEMENT DE PATE A PAPIER AVEC UN AGENT CHELATEUR SUIVI D'UN BLANCHIMENT A UN pH SUPERIEUR A 9
AU665461B2 (en) Method of treating process water
EP0693144A1 (fr) Procede d'epuration d'eau de traitement
AU686024B2 (en) Treatment of chemical pulp with a chelating agent and an oxidizing agent in connection with bleaching
WO1997008381A1 (fr) Procede pour empecher l'accumulation de metaux dans un processus de blanchiment de pate a papier en circuit ferme
WO1994029512A1 (fr) Procede de blanchiment de la pate de cellulose sans produits chimiques chlores
WO1998014657A1 (fr) Oxydation des ions metal perturbateurs dans des procedes de blanchiment
EP0951599B1 (fr) Traitement de pate avec un chelateur sans utiliser de tour de blanchiment
SE512137C2 (sv) Förfarande för blekning av lignocellulosahaltig massa
Dang Pulp pretreatments for improved selectivity and extended oxygen delignification
CA2134730C (fr) Procede rapide de blanchiment sans chlore avec recirculation des filtrats
EP0726980A1 (fr) Procede de separation des ions metalliques de la pate a papier
CA2363939A1 (fr) Methode d'amelioration de la clarte et de l'aptitude au blanchiment de la pate kraft et de reduction de rejets d'effluents de blanchiment

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AT CA FI JP NO US

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
ENP Entry into the national phase

Ref document number: 2219767

Country of ref document: CA

Ref country code: CA

Ref document number: 2219767

Kind code of ref document: A

Format of ref document f/p: F

Ref country code: AT

Ref document number: 1996 9026

Date of ref document: 19961107

Kind code of ref document: A

Format of ref document f/p: F

WWE Wipo information: entry into national phase

Ref document number: 19969026

Country of ref document: AT

ENP Entry into the national phase

Ref country code: US

Ref document number: 1997 945769

Date of ref document: 19971031

Kind code of ref document: A

Format of ref document f/p: F

Ref country code: JP

Ref document number: 1996 533220

Kind code of ref document: A

Format of ref document f/p: F

WWE Wipo information: entry into national phase

Ref document number: 974115

Country of ref document: FI

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载