EP1979532A2 - Procede de traitement d une pulpe de cellulose-lignine - Google Patents

Procede de traitement d une pulpe de cellulose-lignine

Info

Publication number
EP1979532A2
EP1979532A2 EP06839344A EP06839344A EP1979532A2 EP 1979532 A2 EP1979532 A2 EP 1979532A2 EP 06839344 A EP06839344 A EP 06839344A EP 06839344 A EP06839344 A EP 06839344A EP 1979532 A2 EP1979532 A2 EP 1979532A2
Authority
EP
European Patent Office
Prior art keywords
pulp
ozone
chelant
cellulose
stage
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.)
Withdrawn
Application number
EP06839344A
Other languages
German (de)
English (en)
Other versions
EP1979532A4 (fr
Inventor
Dwane Scott Hutto
Haixuan Zou
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.)
University of Maine System
Original Assignee
University of Maine System
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 University of Maine System filed Critical University of Maine System
Publication of EP1979532A2 publication Critical patent/EP1979532A2/fr
Publication of EP1979532A4 publication Critical patent/EP1979532A4/fr
Withdrawn legal-status Critical Current

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
    • D21C9/147—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
    • D21C9/1026—Other features in bleaching processes
    • D21C9/1042—Use of chelating agents

Definitions

  • This invention relates in general to processes for treating cellulose-lignin materials and in particular to a process for treating a cellulose-lignin pulp such as a wood pulp.
  • Wood contains two main components: a fibrous cellulose portion and a non-fibrous lignin portion.
  • the polymeric chains forming the fibrous cellulose portion are aligned with one another and form strong associated bonds with adjacent chains.
  • the lignin is a three-dimensional polymeric material that bonds the cellulosic fibers and is also distributed within the fibers themselves.
  • the wood is converted to pulp for use in paper manufacturing. Pulp comprises wood fibers capable of being slurried or suspended and then deposited on a screen to form a sheet of paper.
  • pulping techniques There are two main types of pulping techniques: mechanical pulping and chemical pulping. In mechanical pulping, the wood is physically separated into individual fibers.
  • the wood chips are digested with chemical solutions to solubilize a portion of the lignin and thus permit its removal.
  • the commonly used chemical pulping processes include: (a) the kraft process, (b) the sulfite process, and (c) the soda process.
  • the kraft process is the most commonly used and involves digesting the wood chips in an aqueous solution of sodium hydroxide ? ⁇ nd sodium sulfide.
  • the wood pulp produced in the pulping process is usually separated into a fibrous mass and washed.
  • the wood pulp after the pulping process is dark colored because it contains residual lignin not removed during digestion which has been chemically modified in pulping to form chiomophoric groups.
  • delignification and bleaching of wood pulp has been carried out with elemental chlorine.
  • chlorine is a very effective bleaching agent
  • the effluents from chlorine bleaching processes contain large amounts of chlorides produced as the by-product of these processes. These chlorides readily corrode processing equipment, thus requiring use of costly materials in the construction of bleach plants.
  • Ozone delignification and bleaching of wood pulp is a process that would greatly benefit the industry if it can be arranged to work efficiently.
  • Ozone has a very high oxidation potential, and is thought to have the potential to be a very efficient delignification agenit.
  • Ozone potentially could benefit the industry by allowing additional closure of the delignificati on-bleaching process. Since an ozone stage would not add any detrimental ions to the black liquor recovery stream, its wash effluent could be used counter-currently with prior stages. By this means, fuel to the recovery boiler wo ⁇
  • U.S. Patent 6,258,207 by Pan discloses a process aimed at pulping non- woody species. The process consists of three stages: acidic chelation stage; followed by alkaline peroxide stage with chelation, which may or may not be enhanced with either ozone or peracetic acid; followed by a final stage of mechanical pulping. The process is aimed at grasses such as hemp and wheat istraw.
  • U.S. Patent 5,034,096 by Hammer et al. discloses a process for bleaching and delignifying cellulose containing material using peroxides, oxygen, and/or ozone with the addition of cyanamide or cyanamide salt.
  • the process includes a peroxide as a bleaching agent
  • the process also includes a stabilizer or complex former to avoid decomposition of the peroxide.
  • the addition of the stabilizer or complex former can be omitted if the heavy metal salts in the cellulose are removed by washing the cellulose prior to the bleaching.
  • U.S. Patent 6,302,997 by Hurter et al. discloses a process that applies only to nonwood species. The process appears to include an acidic chelation ahead of an ozone stage with or without washing in between.
  • U.S. Patent 5,593,544 by Fahlgren et al. applies to any comminuted cellulosic fiber.
  • the process consists of sequestering agent treatment prior to an oxygen "digestion" stage. At least some of the chelation filtrate must be removed prior to the oxygen step.
  • the oxygen stage is followed by a hydrogen peroxide bleach that may contain peracetic acid or ozone. No mention is made of using chelation with the peroxide-ozone stage. .
  • This invention relates to a process of treating a cellulose-lignin pulp.
  • the pulp is contacted with ozone to bleach and delignify the pulp.
  • the ozone stage is conducted without the addition of a peroxide bleaching agent.
  • a chelant is introduced into the ozone stage to improve selectivity of the delignification.
  • the invention relates to a process of treating a- wood pulp.
  • the pulp is contacted with ozone to bleach and delignify the pulp.
  • the ozone stage produces hydrogen peroxide.
  • a chelant is introduced into the ozone stage to tie up trace metals in the pulp and reduce decomposition of the hydrogen peroxide, thereby improving selectivity of the delignification.
  • the invention relates to a prior process of treating a cellulose-lignin pulp in which, in an ozone stage, the pulp is contacted with ozone to bleach and delignify the pulp.
  • the ozone stage produces hydrogen peroxide which decomposes to produce first .free radicals, and the first free radicals activate decomposition of the ozone to produce second free radicals.
  • the first and second free radicals cause degradation of the cellulose.
  • the present invention improves the prior process by introducing a chelant into the ozone stage to reduce decomposition of the hydrogen peroxide, thereby reducing production of the first free radicals. In turn, this reduces activation of the decomposition of the ozone and production of the second free radicals.
  • the reduced production of the first and second free radicals improves - selectivity of the delignification by reducing degradation of the cellulose.
  • This invention relates to an improved process of ozone bleaching and delignification of a cellulose-lignin pulp.
  • the process may be applicable to any type of pulp made from a lignocellulosic material, such as pulps made from different types of plants that contain primarily cellulose and lignin.
  • the pulp is a wood pulp,. More particularly, in some embodiments the wood pulp is a chemical pulp or a recycle pulp.
  • the process is usually suitable for use with pulp having any consistency.
  • the pulp comprises a suspension of the cellulose-lignin material in water
  • the pulp has a consistency within a range of from about 0.2% to about 50% cellulose-lignin material by weight of the pulp.
  • the pulp is contacted with ozone to bleach and delignify the pulp during what is referred to herein as the "ozone stage".
  • the ozone is applied to the pulp in any suitable manner.
  • the pulp is fed into a reactor and ozone is injected into the reactor in a manner sufficient for the ozone to bleach and delignify the pulp.
  • the bleaching and delignifying of the pulp is conducted in the ozone stage without the addition of a peroxide bleaching agent.
  • the ozone is the only bleaching/delignification agent used during the process. However, this does not exclude any peroxide which may be formed as a by-product during the process.
  • the bleaching and delignifying of the pulp may also be conducted without the addition of cyar, ⁇ amide or cyanamide salt.
  • the process of ozone bleaching and delignification is improved according to the invention by introducing a chelant into the ozone stage along with the ozone and the pulp.
  • the introduction of the chelant improves the selectivity of the delignification of the pulp, so that the ozone bleaches and delignifies the pulp without significantly degrading and weakening the cellulosic fibers of the pulp.
  • Any suitable cheiantfc ⁇ can he ⁇ :erl in such as phosphonate chelants, ethylene- diaminetetraacetic acid (EDTA) 5 and/or diethylenetriamine pentaacetic acid (DTPA).
  • the phosphonate chelants are generally preferred for use in the invention.
  • Some nonlimiting examples of phosphonate chelants are the Dequest® 2010 Series based on hydroxyethylidene 1,1-diphosphonic acid which are manufactured by Solutia Inc., St. Louis, Missouri.
  • the chelant(s) can be introduced into the pulp in any suitable amount.
  • the pulp during the ozone stage comprises a suspension of the cellulose- lignin material (e.g.., wood fibers) in water, and the chelant is introduced into the pulp in an amount within a range of from about 1 to about 100 times the total trace metals (by weight), more specifically from about 10 to about 50 times.
  • the selectivity of the delignification is improved compared to the same process without the chelant.
  • the selectivity is improved by at least about 10%, and more preferably by at least about 20%.
  • the selectivity can be defined in any suitable manner.
  • the selectivity can be defined as ⁇ K/ ⁇ V, where ⁇ K is the change in kappa number that measures delignification and ⁇ V is the change in viscosity that characterizes carbohydrate depolymerization.
  • the selectivity can be defined as ⁇ K/ ⁇ V where ⁇ K is the change in permanganate number that measures delignification, as measured in a test that uses potassium permanganate, KMnO ⁇
  • the ozone bleaching and delignification process of the invention can be conducted using any suitable process conditions.
  • the pulp is reacted with the ozone for a time within a range of from about 1 second to " about 5 hours, or more specifically from about 10 seconds to about 10 minutes.
  • the pulp is reacted with the ozone at a temperature within a range of from about 20 0 C to about 90 0 C 5 or more specifically from about 20 0 C to about 35°C.
  • the pulp is reacted with the ozone at a pH within a range of from 1 to about 7, or more specifically from about 2 to about 6.
  • the pulp treated in the process may include trace metal(s) in the suspension nd the chelant may function to tie up the trace ' metals.
  • the process may include the additional steps, before the ozone stage, of determining the species of trace metal and/or the amount of trace metal in the pulp, and then selecting the chelant type and/or chelant dose to match the trace metal based on the trace metal determination.
  • the pH of the ozone stage may also be adjusted depending on the determination of species and amount of trace metals.
  • Improving selectivity by stabilizing hydrogen peroxide in the ozone stage is a surprising finding in view of the prevailing theory in the pulping industry that the destructive free radicals are a by-product of the ozone reaction with lignin.
  • the destructive free radicals are a by-product of the ozone reaction with lignin.
  • ozone will also decompose to very reactive non-selective free radicals. Free radicals from the decomposition of hydrogen peroxide are activators for ozone: decomposition to free radicals. Once started the cycle is self- sustaining until all 1he ozone is depleted.
  • the free radicals produced by the decomposition of ozone and hydrogen peroxide are very reactive and non-selective.
  • ozone reacts with lignin to produce free radicals seems to be correct in the end result, but neglects the important intermediate steps that can be controlled.
  • the r.rmvpnHrmni theory is that the free radicals are a direct result of the lignin reaction with ozone, and since the goal is to react ozone and lignin, then the production of the harmful free radicals cannot be prevented.

Landscapes

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

Abstract

La présente invention concerne un procédé de traitement d’une pulpe de cellulose-lignine. Au cours d’une étape d’ozone, on met la pulpe en contact avec de l’ozone pour blanchir et délignifier la pulpe. On réalise l’étape d’ozone sans ajout d’un agent de blanchiment peroxyde. On introduit un agent chélatant à l’étape d’ozone de manière à améliorer la sélectivité de la délignification.
EP06839344A 2005-12-14 2006-12-12 Procede de traitement d une pulpe de cellulose-lignine Withdrawn EP1979532A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/300,126 US20070131364A1 (en) 2005-12-14 2005-12-14 Process for treating a cellulose-lignin pulp
PCT/US2006/047416 WO2007070527A2 (fr) 2005-12-14 2006-12-12 Procede de traitement d’une pulpe de cellulose-lignine

Publications (2)

Publication Number Publication Date
EP1979532A2 true EP1979532A2 (fr) 2008-10-15
EP1979532A4 EP1979532A4 (fr) 2011-09-28

Family

ID=38138100

Family Applications (1)

Application Number Title Priority Date Filing Date
EP06839344A Withdrawn EP1979532A4 (fr) 2005-12-14 2006-12-12 Procede de traitement d une pulpe de cellulose-lignine

Country Status (10)

Country Link
US (1) US20070131364A1 (fr)
EP (1) EP1979532A4 (fr)
JP (1) JP2009520120A (fr)
CN (1) CN101426975B (fr)
AU (1) AU2006326561B8 (fr)
BR (1) BRPI0619948A2 (fr)
CA (1) CA2633540A1 (fr)
NO (1) NO20082756L (fr)
WO (1) WO2007070527A2 (fr)
ZA (1) ZA200804881B (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008033747A2 (fr) * 2006-09-11 2008-03-20 Curis, Inc. Petites molécules multifonctionnelles servant d'agents anti-prolifératifs
BR112014031092B1 (pt) 2012-06-13 2022-05-17 University Of Maine System Board Of Trustees Processo para formar nanofibras de celulose a partir de um material celulósico
CN106283794B (zh) * 2016-11-02 2017-11-21 江南大学 一种利用臭氧去除麻纤维木质素的方法

Family Cites Families (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4119486A (en) * 1975-08-14 1978-10-10 Westvaco Corporation Process for bleaching wood pulp with ozone in the presence of a cationic surfactant
US4238282A (en) * 1979-07-23 1980-12-09 Nalco Chemical Company Chemical treatments in bleaching stages which increase pulp brightness
DE3544398A1 (de) * 1985-12-16 1987-06-19 Sueddeutsche Kalkstickstoff Verfahren zur bleiche und delignifizierung von zellstoffhaltigen produkten
US5188708A (en) * 1989-02-15 1993-02-23 Union Camp Patent Holding, Inc. Process for high consistency oxygen delignification followed by ozone relignification
US5164044A (en) * 1990-05-17 1992-11-17 Union Camp Patent Holding, Inc. Environmentally improved process for bleaching lignocellulosic materials with ozone
US5164043A (en) * 1990-05-17 1992-11-17 Union Camp Patent Holding, Inc. Environmentally improved process for bleaching lignocellulosic materials with ozone
EP0565625A1 (fr) * 1991-01-03 1993-10-20 Union Camp Patent Holding, Inc. Procede de blanchiment de pate lignocellulosique sans utilisation de chlore
SE468355B (sv) * 1991-04-30 1992-12-21 Eka Nobel Ab Blekning av kemisk massa genom behandling med komplexbildare och ozon
US5364503A (en) * 1992-02-20 1994-11-15 Macmillan Bloedel Limited Nitric oxide treatment for ozone bleaching
BE1006057A3 (fr) * 1992-07-06 1994-05-03 Solvay Interox Procede pour la delignification d'une pate a papier chimique.
WO1994010377A1 (fr) * 1992-10-23 1994-05-11 Macmillan Bloedel Limited Blanchiment a l'ozone ameliore
US5364506A (en) * 1993-04-28 1994-11-15 The Board Of Trustees Of The Leland Stanford Junior University Method and apparatus for partial oxidation of methane and cogeneration of electrical energy
SE9301960L (sv) * 1993-06-08 1994-07-25 Kvaerner Pulping Tech Blekning av kemisk massa med peroxid vid övertryck
SE502667C2 (sv) * 1993-07-12 1995-12-04 Kvaerner Pulping Tech Behandling av fibermaterial med komplexbildare före kokning
US5662803A (en) * 1996-04-09 1997-09-02 Nalco Chemical Company Stabilizers for additives in aqueous systems containing ozone
CA2189724A1 (fr) * 1996-07-08 1998-01-09 Suezone Chow Methode de reduction en pate
PL332079A1 (en) * 1996-09-11 1999-08-30 Solvay Interox Sa Paper pulp bleaching method
DE69912128T2 (de) * 1998-04-17 2004-06-17 Alberta Research Council, Inc., Edmonton Verfahren zur herstellung lignocellulosehaltiger pulpe aus nicht holzartigem material
SE514947C2 (sv) * 1998-09-09 2001-05-21 Valmet Fibertech Ab Blekning av massa med ozon innefattande oxalsyratillsats
US6302997B1 (en) * 1999-08-30 2001-10-16 North Carolina State University Process for producing a pulp suitable for papermaking from nonwood fibrous materials
US7396974B2 (en) * 2002-02-08 2008-07-08 University Of Maine Oxidation using a non-enzymatic free radical system mediated by redox cycling chelators
DE10320618A1 (de) * 2003-05-08 2004-11-18 Papierfabrik Albbruck Gmbh & Co. Kg Verfahren zum Bleichen von Faserstoffen

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
No further relevant documents disclosed *
See also references of WO2007070527A2 *

Also Published As

Publication number Publication date
AU2006326561B8 (en) 2011-04-07
NO20082756L (no) 2008-08-11
CA2633540A1 (fr) 2007-06-21
BRPI0619948A2 (pt) 2011-10-25
ZA200804881B (en) 2009-03-25
WO2007070527A2 (fr) 2007-06-21
EP1979532A4 (fr) 2011-09-28
AU2006326561B2 (en) 2011-03-17
JP2009520120A (ja) 2009-05-21
CN101426975A (zh) 2009-05-06
CN101426975B (zh) 2011-09-21
WO2007070527A3 (fr) 2008-11-13
AU2006326561A1 (en) 2007-06-21
US20070131364A1 (en) 2007-06-14

Similar Documents

Publication Publication Date Title
JP2843892B2 (ja) リグノセルロース含有パルプの漂白方法
CA2067295C (fr) Procede de blanchiment de matiere contenant de la lignocellulose
US6702921B2 (en) Methods to enhance pulp bleaching and delignification using an organic sulfide chelating agent
DE19614587A1 (de) Verfahren und Bleichlösung zum Bleichen von cellulosischen Faserstoffen
CA1154205A (fr) Amelioration de la blancheur de la pate a papier blanchie a l'ozone
US5639348A (en) Bleaching compositions comprising sulfamates and borates or gluconates and processes
US20150240423A1 (en) Effect of low dose xylanase on pulp in prebleach treatment process
EP0789798B1 (fr) Procede de delignification et de blanchiment de cellulose chimique
AU2006326561B8 (en) Process for treating a cellulose-lignin pulp
JP5285896B2 (ja) 漂白アルカリ化学パルプの製造方法
WO2008060519A2 (fr) Procédé de blanchiment amélioré avec au moins une étape d'extraction
US10006168B2 (en) Method for treating chemical pulps by treatment with ozone in the presence of magnesium ions
US11384480B2 (en) Method for bleaching paper pulp
US20120031575A1 (en) Pulp Bleaching and Alkaline Extraction Method
US20030168190A1 (en) Method for controlling the delignfication and bleaching of a pulp suspension
US20100224336A1 (en) Process of bleaching a wood pulp
US5645688A (en) Bleaching compositions and processes employing sulfamates and polyaminocarboxylic acids
LT3269B (en) Process for bleaching of lignocellulose-containing pulps

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: 20080714

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA HR MK RS

R17D Deferred search report published (corrected)

Effective date: 20081113

DAX Request for extension of the european patent (deleted)
RBV Designated contracting states (corrected)

Designated state(s): FI SE

REG Reference to a national code

Ref country code: DE

Ref legal event code: 8566

A4 Supplementary search report drawn up and despatched

Effective date: 20110831

RIC1 Information provided on ipc code assigned before grant

Ipc: D21C 9/10 20060101AFI20110825BHEP

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20120330