EP0547100B1 - Procede de traitement de la pate lignocellulosique et appareil permettant de realiser ce procede - Google Patents

Procede de traitement de la pate lignocellulosique et appareil permettant de realiser ce procede Download PDF

Info

Publication number
EP0547100B1
EP0547100B1 EP91915560A EP91915560A EP0547100B1 EP 0547100 B1 EP0547100 B1 EP 0547100B1 EP 91915560 A EP91915560 A EP 91915560A EP 91915560 A EP91915560 A EP 91915560A EP 0547100 B1 EP0547100 B1 EP 0547100B1
Authority
EP
European Patent Office
Prior art keywords
washing
treatment
enzyme
pulp
stock
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Lifetime
Application number
EP91915560A
Other languages
German (de)
English (en)
Other versions
EP0547100A1 (fr
Inventor
Lars Saaby Pedersen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Novo Nordisk AS
Original Assignee
Novo Nordisk AS
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 Novo Nordisk AS filed Critical Novo Nordisk AS
Publication of EP0547100A1 publication Critical patent/EP0547100A1/fr
Application granted granted Critical
Publication of EP0547100B1 publication Critical patent/EP0547100B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
    • D21C5/005—Treatment of cellulose-containing material with microorganisms or enzymes
    • 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
    • D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents

Definitions

  • a common stage in the treatment of wood chips for paper production is chemical pulping, e.g. the so-called kraft process which is an alkaline sulphate cooking of the wood chips.
  • the native wood chips contain around 30% lignin, and at the end of the chemical cooking process less than 5% of the lignin compounds is still left in the pulp. Due to the strong brown color of the remaining lignin and its tendency to darken in UV light or by oxidation this has to be removed in order to obtain a white pulp without the tendency to color reversion.
  • After the sulphate cooking a multistage washing of the unbleached kraft brown stock takes place. The well washed brown stock can then be treated with an enzyme preparation followed by a subsequent wash before entering the bleach plant.
  • the invention comprises an improvement of this conventional multistage washing of the unbleached kraft brown stock, followed by the enzyme treatment with the subsequent wash, whereby this improvement is a modification, which improves the economy and facilitates the processing.
  • the brown color can be removed by a multistage bleaching using e.g. chlorine and/or chlorine dioxide.
  • a multistage bleaching using e.g. chlorine and/or chlorine dioxide. Due to the ever increasing environmental concern, the dosage of chlorine and/or chlorine dioxide has to be kept at a minimum, and it is for that reason that the enzymatic treatment of the kraft cooked pulp has been introduced, vide e.g. The third International Conference on Biotechnology in the Pulp and Paper Industry, Swiss, 16-19.6, 1986, page 67-69.
  • the invention comprises the above indicated processes 2) and 3) and is an improvement thereof, as explained in more detail in the following.
  • the purpose of the invention is the provision of a process for treatment of lignocellulosic pulp which requires a less expensive apparatus or stated otherwise the provision of a reduction of the price of the prior art method for treatment of lignocellulosic pulp comprising a multistage washing of the unbleached brown kraft stock with subsequent enzyme treatment, washing and bleaching, and a corresponding apparatus for performance of the process.
  • the purpose of the invention can be fulfilled, if the enzymatic treatment with the subsequent wash is abandoned altogether and the enzymatic treatment is introduced between two brown stock washing units in the multistage washings of the unbleached kraft brown stock, or stated otherwise if the enzyme treatment is introduced upstream the prior art position of the enzyme treatment in the multistage washing, in such manner that the multistage washing for washing out of impurities from the kraft cooking and washing out of the residues from the enzyme treatment is combined.
  • the process for treatment of lignocellulosic pulp according to the invention comprising a multistage washing of the unbleached kraft brown stock and a treatment with a xylanase with high pH activity and stability and high heat stability is characterized by the fact that the xylanase treatment is introduced between two brown stock washing units in such manner that the washed stock from the outlet side of one or more of the washing units is transported to a holding tank, that the xylanase with high pH activity and stability and high heat stability is added directly upstream the holding tank, and that the enzyme treated stock is passed further on in the process to the next washing unit.
  • another non-chlorine bleaching stage e.g. an oxygen delignification stage or an ozone stage may be included either before or after the enzyme stage.
  • Fig. 1 prior art
  • Fig. 2 invention
  • the invention requires one washing unit less than the prior art process, and thus, the process according to the invention fulfils the purpose of the invention.
  • the tank on Fig. 1 used for the enzyme treatment normally also serves as buffer tank between the kraft cooking and the bleaching plant the residence time of the pulp in the tank often varies within a wide range, e.g. between 30 minutes and 24 hours.
  • the tank is an integrated part of the washing process. It only serves the need for holding time for the enzyme treatment, which makes it much easier to control the enzyme treatment time.
  • the invention provides a much better connection to the existing wash water streams.
  • wash water obtained in the process according to the invention will end up in the recovery system for the kraft cooking process, which means that everything that is solubilized during the enzyme treatment will be burned in the recovery boiler whereby the BOD5 load from the enzyme stage on the effluent streams is eliminated.
  • the wash water from the washing stage after the enzyme treatment normally has to be sewered.
  • the enzyme treatment according to the invention also releases more cooking chemicals from the pulp than a conventional wash with water. This makes it possible to obtain an even better recovery of cooking chemicals than normally obtained.
  • the three washing units on Fig. 2 are not limiting to the invention, but just an example. Each single unit can represent more than one washing stage. With three washing units one, two or three enzyme treatment units can be introduced according to the invention; just one enzyme treatment unit is shown on Fig. 2.
  • the invention comprises an apparatus for performance of the process according to the invention.
  • the apparatus according to the invention is characterized by the fact that a holding tank with piping with facilities for introduction of enzyme is introduced downstream one or more of the washing units except for the last washing unit, that piping is provided for further transport of the stock to the next washing unit, and that the conventional enzyme treatment unit downstream the washing unit is abandoned.
  • the pulp P was diluted with fresh water to a consistency of 1% DS and then reconcentrated to a consistency of approximately 20% on a wire screen.
  • This washing sequence is the standard washing stage used throughout this example.
  • This pulp sample was divided into two halves.
  • EXU xylanase activity unit appears from AF 293.9/1, obtainable on request from NOVO NORDISK A/S, Novo Allé, DK-2880 Bagsvaerd, Denmark.
  • the xylanase stage was carried out as follows.
  • the pulp was diluted to the desired consistency by addition of fresh water.
  • the enzyme solution was added and mixed into the pulp by vigorous mixing.
  • the pulp was then placed in a water bath to ensure constant temperature for the remainder of the treatment time. The pulp was not mixed during the three hours of holding time.
  • pulp sample which was enzyme treated between the first and the second washing stage, was carried out according to the invention and will be referred to later as inv 1-2 .
  • the second half of the one stage washed pulp was carried through another standard washing stage. After washing the pH of the pulp suspension was 8.7.
  • the enzyme treatment was carried out as described above.
  • FXU xylanase activity unit appears from AF 293.6/1, obtainable on request from NOVO NORDISK A/S, Novo Allé, DK-2880 Bagsvaerd, Denmark.
  • the enzyme treatment was made as described above.
  • the xylanases used in this example were selected according to their pH optimum in relation to the pH of the pulp.
  • the bleachings were carried out under the following conditions:
  • Kappa number of the pulps after the (D50 C50) E bleachings Kappa number delta Kappa number % Control 2.85 - Prior 2.52 11.6 inv 1-2 2.50 12.3 inv 2-3 2.31 19.0

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Biochemistry (AREA)
  • Microbiology (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)
  • Chemical And Physical Treatments For Wood And The Like (AREA)

Claims (2)

  1. Procédé de traitement d'une pâte lignocellulosique comportant un lavage en plusieurs étapes de pâte kraft brune non-blanchie et un traitement à l'aide d'une xylanase ayant une activité et une stabilité à pH élevé et une stabilité à température élevée, caractérisé en ce que le traitement à la xylanase est introduit entre deux unités de lavage de pâte brune de manière telle que la pâte lavée provenant du côté sortie de l'une ou plusieurs des unités de lavage est transportée vers un réservoir de retenue, que la xylanase ayant une activité et une stabilité à pH élevé et une stabilité à température élevée est ajoutée directement en amont du réservoir de retenue, et que la pâte traitée à l'enzyme passe plus loin dans le procédé vers l'unité de lavage suivante.
  2. Appareil pour mettre en oeuvre le procédé selon la revendication 1, caractérisé en ce qu'un réservoir de retenue ayant une tuyauterie munie d'accessoires destinés à l'introduction d'une enzyme est introduit en aval d'une ou de plusieurs des unités de lavage à l'exception de la dernière unité de lavage, en ce que tuyauterie est prévue pour transporter la pâte à papier vers le réservoir de lavage suivant, et en ce que l'unité de traitement à l'enzyme habituel située en aval de l'unité de lavage est abandonnée.
EP91915560A 1990-08-24 1991-08-21 Procede de traitement de la pate lignocellulosique et appareil permettant de realiser ce procede Expired - Lifetime EP0547100B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DK203490A DK203490D0 (da) 1990-08-24 1990-08-24 Fremgangsmaade til behandling af lignocellulosepulp og apparat til udfoerelse af processen
DK2034/90 1990-08-24
PCT/DK1991/000239 WO1992003608A1 (fr) 1990-08-24 1991-08-21 Procede de traitement de la pate lignocellulosique et appareil permettant de realiser ce procede

Publications (2)

Publication Number Publication Date
EP0547100A1 EP0547100A1 (fr) 1993-06-23
EP0547100B1 true EP0547100B1 (fr) 1995-02-22

Family

ID=8109613

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91915560A Expired - Lifetime EP0547100B1 (fr) 1990-08-24 1991-08-21 Procede de traitement de la pate lignocellulosique et appareil permettant de realiser ce procede

Country Status (11)

Country Link
EP (1) EP0547100B1 (fr)
JP (1) JPH05509137A (fr)
AT (1) ATE118842T1 (fr)
BR (1) BR9106763A (fr)
CA (1) CA2090338A1 (fr)
DE (1) DE69107620D1 (fr)
DK (1) DK203490D0 (fr)
ES (1) ES2069307T3 (fr)
FI (1) FI930803A0 (fr)
NZ (1) NZ239501A (fr)
WO (1) WO1992003608A1 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2521615T3 (es) 2001-06-06 2014-11-13 Novozymes A/S Endo-beta-1,4-glucanasa
NZ537597A (en) 2002-06-14 2008-07-31 Diversa Corp Xylanases, nucleic acids encoding them and methods for making and using them
CA2638801C (fr) 2006-02-14 2016-12-13 Verenium Corporation Xylanases, acides nucleiques codant pour elles et leurs procedes de preparation et d'utilisation
BRPI0820615B1 (pt) 2007-12-06 2020-05-12 Novozymes A/S Célula microbiana hospedeira recombinante, métodos para produzir um polipeptídeo tendo atividade de acetil-xilano esterase, método para produzir uma proteína e método de degradar um material contendo xilano
CN107338233A (zh) 2009-09-29 2017-11-10 诺维信股份有限公司 具有木聚糖酶活性的多肽和编码该多肽的多核苷酸
ES2574054T3 (es) 2009-11-06 2016-06-14 Novozymes, Inc. Polipéptidos con actividad de xilanasa y polinucleótidos que los codifican

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0373107B1 (fr) * 1988-11-23 1994-03-23 Sandoz Ag Utilisation d'enzymes de Auréobasidium pullulans pour le blanchiment de pâte
FI90888B (fi) * 1989-02-14 1993-12-31 Enso Gutzeit Oy Menetelmä selluloosamassan valkaisemiseksi

Also Published As

Publication number Publication date
ES2069307T3 (es) 1995-05-01
FI930803A (fi) 1993-02-23
JPH05509137A (ja) 1993-12-16
WO1992003608A1 (fr) 1992-03-05
NZ239501A (en) 1993-01-27
BR9106763A (pt) 1993-06-29
EP0547100A1 (fr) 1993-06-23
ATE118842T1 (de) 1995-03-15
FI930803A0 (fi) 1993-02-23
DK203490D0 (da) 1990-08-24
DE69107620D1 (de) 1995-03-30
CA2090338A1 (fr) 1992-02-25

Similar Documents

Publication Publication Date Title
JP4499280B2 (ja) 過酸による化学パルプの漂白
EP0512590B1 (fr) Procédé de blanchiment de matériaux contenant de la lignocellulose
SE439508B (sv) Sett for blekning av i vatten uppslammade oxygendelignifierade, cellulosahaltiga massor
WO1994012721A1 (fr) Procede de delignification de pulpe contenant de la cellulose ligneuse
US5571378A (en) Process for high-pH metal ion chelation in pulps
EP0395792A2 (fr) Procédé de blanchiment de pâte
US6221206B1 (en) Method for oxygen delignification of a digested pulp
EP0547100B1 (fr) Procede de traitement de la pate lignocellulosique et appareil permettant de realiser ce procede
US4560437A (en) Process for delignification of chemical wood pulp using sodium sulphite or bisulphite prior to oxygen-alkali treatment
US4274912A (en) Process for bleaching preoxidized paper pulp
JP5232164B2 (ja) 高温での最終オゾン処理によって化学紙パルプを漂白する方法
WO1996009434A1 (fr) Procede de blanchiment de pate kraft
EP0464110B1 (fr) Procede de blanchiment servant a la production de pulpes tres claires
US3884752A (en) Single vessel wood pulp bleaching with chlorine dioxide followed by sodium hypochlorite or alkaline extraction
EP0513140B2 (fr) Procede de blanchiment de pulpe chimique
US6319357B1 (en) Method for two-stage oxygen bleaching and delignification of chemical pulp
US4238281A (en) Simplified bleaching process
EP0656966B1 (fr) Traitement pour eaux residuelles
US5728264A (en) Avoidance of salt scaling by acidic pulp washing process
KR100538083B1 (ko) 리그노셀룰로오스성 물질의 산소 탈리그닌화
US7182835B2 (en) Two-stage chlorine bleaching process with filtrate recirculation
JPH08503749A (ja) リグノセルロース含有パルプの漂白方法
WO1992007998A1 (fr) Procede de blanchiment de pate
JPH05247864A (ja) セルロースパルプの漂白法
EP0520140A1 (fr) Blanchiment par ozone-extraction alcaline sans lavage intermédiaire

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19930115

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LI LU NL SE

17Q First examination report despatched

Effective date: 19940422

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LI LU NL SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 19950222

Ref country code: LI

Effective date: 19950222

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19950222

Ref country code: DK

Effective date: 19950222

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19950222

Ref country code: CH

Effective date: 19950222

REF Corresponds to:

Ref document number: 118842

Country of ref document: AT

Date of ref document: 19950315

Kind code of ref document: T

REF Corresponds to:

Ref document number: 69107620

Country of ref document: DE

Date of ref document: 19950330

ET Fr: translation filed
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2069307

Country of ref document: ES

Kind code of ref document: T3

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19950509

Year of fee payment: 5

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19950523

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 19950818

Year of fee payment: 5

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19950821

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19950822

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19950824

Year of fee payment: 5

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19950831

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19960116

Year of fee payment: 5

26N No opposition filed
GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19950821

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Effective date: 19960821

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19960822

Ref country code: ES

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 19960822

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Effective date: 19960831

BERE Be: lapsed

Owner name: NOVO NORDISK A/S

Effective date: 19960831

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19970430

EUG Se: european patent has lapsed

Ref document number: 91915560.6

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 19990601