EP0190723A1 - Procédé pour l'amélioration des propriétés mécaniques d'une pâte à papier chimique ou semi-chimique de bagasse - Google Patents

Procédé pour l'amélioration des propriétés mécaniques d'une pâte à papier chimique ou semi-chimique de bagasse Download PDF

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Publication number
EP0190723A1
EP0190723A1 EP86101427A EP86101427A EP0190723A1 EP 0190723 A1 EP0190723 A1 EP 0190723A1 EP 86101427 A EP86101427 A EP 86101427A EP 86101427 A EP86101427 A EP 86101427A EP 0190723 A1 EP0190723 A1 EP 0190723A1
Authority
EP
European Patent Office
Prior art keywords
chemical
oxidizing agent
treatment
bagasse
acid
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Withdrawn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
EP86101427A
Other languages
German (de)
English (en)
French (fr)
Inventor
Jacques Dr. Hageman
Lucien Plumet
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.)
Solvay Chimie SA
Original Assignee
Interox SA
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 Interox SA filed Critical Interox SA
Publication of EP0190723A1 publication Critical patent/EP0190723A1/fr
Withdrawn legal-status Critical Current

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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

Definitions

  • the present invention relates to a method for improving the mechanical properties of chemical or semi-chemical bagasse pulp containing marrow.
  • Bagasse is a lignocellulosic material which generally contains a significant amount of marrow. This is made up of a cellulosic constituent, the parenchyma, which does not have the fibrous structure and cannot be used for papermaking.
  • the bagasse Before cooking for the pulping, the bagasse generally undergoes a pretreatment of mechanical purification aiming at eliminating part of the marrow which it contains.
  • Chemical and semi-chemical paper pulps made from cellulosic materials, in particular bagasse pulps are generally subjected to treatments with oxidizing agents to reduce their lignin content and improve their whiteness. These known methods are generally sequential treatments which comprise several successive bleaching stages, possibly interspersed with washing, dilution and / or concentration stages. To achieve the desired residual lignin level and whiteness, it has thus been proposed to subject the chemical and semi-chemical bagasse pastes to the oxidizing action of chlorine in an acid medium and then to follow this step with an extraction step.
  • Patent US-A-4404061 JJ CAEL, INTERNATIONAL PAPER Co discloses a process for delignification and bleaching of lignocellulosic materials using peroxymonosulfuric acid or a salt of this acid which makes it easier to separate the cellulose non-cellulosic materials (x column 1, lines 50 to 56 and lines 25 to 28 x). Bagasse is cited among the lignocellulosic raw materials (x column 2, line 61 x).
  • the invention overcomes the disadvantages of the known processes by providing a new process for improving the mechanical properties of chemical pulps and semi-chemical bagasse containing a high proportion of marrow, which achieves high brightness levels decreasing appreciably the coloring as well as the polluting load of the effluents.
  • the invention relates to a method for improving the mechanical properties of a chemical or semi-chemical bagasse dough containing at least 25% by weight of marrow, according to which the dough is subjected to a treatment by means of an oxidizing agent; according to the invention, the oxidizing agent is selected from persulfuric acids and their salts.
  • bagasse is intended to denote the fibrous vascular bundles of the stems of plants other than wood belonging to the class of monocots such as cereal straws, sugar cane and cane from EUR, bamboo, esparto, corn stalks, rushes and reeds as well as sabadilla.
  • the invention applies very particularly to crushed stems of sugar cane in the state in which they arise after the sugar extraction operation.
  • the method according to the invention is intended for all chemical or semi-chemical bagasse pastes, that is to say on the one hand chemical pastes having undergone a delignifying treatment in the presence of chemical reagents such as sodium in alkaline medium (kraft or sulphate cooking), sulfur dioxide or a metal salt of sulfurous acid in acid medium (sulphite cooking), a salt of sulfurous acid in neutral medium (semi-chemical cooking in neutral sulfite also called NSSC) and on the other hand semi-chemical pastes obtained by treatment with cold caustic soda followed by mechanical defibration.
  • chemical reagents such as sodium in alkaline medium (kraft or sulphate cooking), sulfur dioxide or a metal salt of sulfurous acid in acid medium (sulphite cooking), a salt of sulfurous acid in neutral medium (semi-chemical cooking in neutral sulfite also called NSSC) and on the other hand semi-chemical pastes obtained by treatment with cold caustic soda followed by mechanical defibration.
  • the invention is particularly intended for pasta with a high marrow content, such as those where this content is between 25 and 40% and preferably between 30 and 40%.
  • the treatment of the dough consists in subjecting it to an oxidizing agent selected from persulfuric acids and their salts.
  • an oxidizing agent selected from persulfuric acids and their salts.
  • all persulfuric acids in the liquid state or in aqueous or organic solution may be suitable, as well as all the salts of these acids.
  • Peroxymonosulfuric acid also called Caro acid, is preferred.
  • the quantity of oxidizing agent which it is advisable to use depends on a large number of parameters, among which appear in particular the nature of the selected bagasse, the purification pretreatment which it has undergone, the technique selected for pulping, the oxidizing agent selected, any subsequent steps in the bleaching sequence and the degree of whiteness sought.
  • the oxidizing agent is generally used in sufficient quantity health so that at the end of the complete whitening sequence, the dough has acquired a high final whiteness, most often greater than 80 degrees from the ISO standard.
  • Caro acid in an amount of between 0.1 and 8 g per 100 g of dry paste. Most often, it is between 0.5 and 5 g / 100 g of dry dough.
  • the temperature at which the treatment with the oxidizing agent is carried out is not critical. It is generally in the range from 298 to 343 K. The selection of an optimum temperature value depends on the possibilities of the apparatus used. Generally low temperatures in the range of 298 to 313 K are preferred.
  • the consistency or weight content of the mixture formed from the bagasse dough and the oxidizing agent is generally, in the process according to the invention, at least 2X and most often at least 3X. It generally does not exceed 40% and more often than not 30%.
  • the treatment of bagasse dough with the oxidizing agent can be carried out in the presence of additives such as, for example, compounds of an acidic nature or pH regulators such as buffers.
  • the acidic compounds can be sulfuric, hydrochloric, nitric or orthophosphoric acids. Sulfuric acid is preferred. Bicarbonates of alkali metals or of ammonium can be chosen alone or as a mixture with a compound with an acidic character as pH regulators.
  • the process according to the invention is generally carried out in the presence of sulfuric acid.
  • the dose of sulfuric acid is generally 0.1 to 20% of the weight of dry bagasse. It is also possible to use other additives such as sequestering and stabilizing agents, surfactants, agents capable of protecting the cellulosic chains to prevent their depolymerization, wetting agents, activating agents and anti-corrosion agents.
  • the duration of the treatment with the oxidizing agent is variable and depends on various factors, in particular the nature of the bagasse, the technique used for pulping, the oxidizing agent selected and the working temperature. In principle, there is no maximum limit to the duration of treatment with the oxidizing agent and, if care is taken to exceed a minimum required to reach the physico-chemical equilibria and often being around 50 at 80 minutes, it is safe for the dough to prolong the treatment, for example when it is imposed by the residence time in an existing apparatus. In general, the duration of the treatment with the oxidizing agent is from 15 to 150 minutes and most often from 60 to 105 minutes.
  • the oxidizing agent used is peroxymonosulfuric acid or Caro acid.
  • the Caro acid is preferably used in the form of a solution.
  • the solvent is most often water.
  • the amount of solvent is advantageously at least 0.1% and generally does not exceed 99.5% of the total weight of the mixture which essentially comprises bagasse paste, the solvent, Caro acid and any additives.
  • the solvent is water, it is used in an amount of at least 0.5X and most often at least 1% of the total weight of the mixture. In general, the amount of water used does not exceed 95%, most often not 90X and preferably not 85X of the total weight of the mixture.
  • the treatment with Caro acid is carried out under acidic or neutral pH conditions in a wide range of pH values ranging from 1 to 7.
  • the choice of a value particular pH must be done according to the type of cooking to which the dough was subjected and according to the content of it in alkali or acid.
  • Preferred pH values are between 1 and 3.
  • the treatment with the oxidizing agent can be followed by a conventional bleaching sequence using bleaching agents well known for bleaching bagasse pulp such as chlorine in an acid medium (step C), caustic soda (step E of alkaline extraction), sodium or calcium hypochlorite in alkaline medium (step H), hydrogen peroxide in alkaline medium (step P) and chlorine dioxide in acid medium (step D).
  • bleaching agents well known for bleaching bagasse pulp such as chlorine in an acid medium (step C), caustic soda (step E of alkaline extraction), sodium or calcium hypochlorite in alkaline medium (step H), hydrogen peroxide in alkaline medium (step P) and chlorine dioxide in acid medium (step D).
  • bleaching agents well known for bleaching bagasse pulp such as chlorine in an acid medium (step C), caustic soda (step E of alkaline extraction), sodium or calcium hypochlorite in alkaline medium (step H), hydrogen peroxide in alkaline medium (step P) and chlorine dioxide in acid medium (step D).
  • the application of the pretreatment, with the oxidizing agent, in accordance with the process according to the invention most often makes it possible to substantially reduce the amounts of these reagents, particularly those of chlorinated reagents. This results in the significant advantage of a reduction in the content of chloride ions and of chlorinated organic compounds in the effluents of the bleaching installation and therefore a considerable reduction in environmental pollution.
  • the method according to the invention makes it possible to obtain pasta with a better degree of whiteness than those obtained by the methods of the prior art. All other things remaining equal, it thus allows the use of bagasse whose residual marrow content is higher, which reduces the cost of the pretreatment of purification or demoelling. In general, bagasse with a residual marrow content of between 30 and 40% is suitable in most cases.
  • a chemical paste from Iraqi sugar cane bagasse which has been cooked with lime (initial whiteness 37.6 ° ISO, kappa index 39.6) and still containing 25 to 35X by weight of marrow has been subjected to a conventional whitening sequence in four stages : CEHH (example 1R) or PCEH (example 2R) under the following operating conditions. The percentages of reagents are given relative to the weight of the dry paste.
  • Table II shows the results of the evaluations carried out on the bleached pasta according to the same methods as in Examples 1R and 2R.
  • the notation C A symbolizes the treatment with Caro acid.
  • Examples 3 and 4 also show that it is possible, with a whiteness equal to that obtained with the reference CEHH sequence (example 1R), to obtain, with the process according to the invention, the elimination of the second step H, a pulp with better solidity, a reduction of 8 to 5.2% (example 3) and from 8 to 4.75% (example 4) of the total load of active chlorine and less pollution of the effluents.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
EP86101427A 1985-02-04 1986-02-04 Procédé pour l'amélioration des propriétés mécaniques d'une pâte à papier chimique ou semi-chimique de bagasse Withdrawn EP0190723A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8501608A FR2576930B1 (fr) 1985-02-04 1985-02-04 Procede pour la delignification et le blanchiment de pate a papier chimique ou semi-chimique de bagasse
FR8501608 1985-02-04

Publications (1)

Publication Number Publication Date
EP0190723A1 true EP0190723A1 (fr) 1986-08-13

Family

ID=9315961

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86101427A Withdrawn EP0190723A1 (fr) 1985-02-04 1986-02-04 Procédé pour l'amélioration des propriétés mécaniques d'une pâte à papier chimique ou semi-chimique de bagasse

Country Status (13)

Country Link
EP (1) EP0190723A1 (enrdf_load_stackoverflow)
JP (1) JPS61179390A (enrdf_load_stackoverflow)
CN (1) CN86101158A (enrdf_load_stackoverflow)
AU (1) AU5293886A (enrdf_load_stackoverflow)
BR (1) BR8600421A (enrdf_load_stackoverflow)
EG (1) EG17850A (enrdf_load_stackoverflow)
ES (1) ES8802335A1 (enrdf_load_stackoverflow)
FR (1) FR2576930B1 (enrdf_load_stackoverflow)
IN (1) IN164977B (enrdf_load_stackoverflow)
PH (1) PH21180A (enrdf_load_stackoverflow)
PT (1) PT81909B (enrdf_load_stackoverflow)
TN (1) TNSN86016A1 (enrdf_load_stackoverflow)
ZA (1) ZA86598B (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0415149A3 (en) * 1989-08-18 1992-01-29 Degussa Aktiengesellschaft Process for bleaching and delignification of lignocellulosic materials
WO1992015752A1 (fr) * 1991-03-11 1992-09-17 Interox International S.A. Procede pour le blanchiment d'une pate a papier chimique et application de ce procede au blanchiment d'une pate kraft
EP0560421A1 (fr) * 1992-03-09 1993-09-15 SOLVAY INTEROX (Société Anonyme) Procédé pour la décoloration et le blanchiment de vieux papiers colorés
US5246543A (en) * 1989-08-18 1993-09-21 Degussa Corporation Process for bleaching and delignification of lignocellulosic materials

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009015555A1 (fr) * 2007-07-27 2009-02-05 Shandong Tralin Paper Co., Ltd Pâte à papier à base d'herbe utilisée dans la fabrication du papier et son procédé de préparation

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4404061A (en) * 1981-08-17 1983-09-13 International Paper Company Bleaching of lignocellulosic materials with monopersulfuric acid or its salts

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4404061A (en) * 1981-08-17 1983-09-13 International Paper Company Bleaching of lignocellulosic materials with monopersulfuric acid or its salts

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0415149A3 (en) * 1989-08-18 1992-01-29 Degussa Aktiengesellschaft Process for bleaching and delignification of lignocellulosic materials
US5091054A (en) * 1989-08-18 1992-02-25 Degussa Corporation Process for bleaching and delignification of lignocellulosic
US5246543A (en) * 1989-08-18 1993-09-21 Degussa Corporation Process for bleaching and delignification of lignocellulosic materials
WO1992015752A1 (fr) * 1991-03-11 1992-09-17 Interox International S.A. Procede pour le blanchiment d'une pate a papier chimique et application de ce procede au blanchiment d'une pate kraft
BE1004674A3 (fr) * 1991-03-11 1993-01-12 Interox Internat Sa Procede pour le blanchiment d'une pate a papier chimique et application de ce procede au blanchiment d'une pate kraft.
AU660301B2 (en) * 1991-03-11 1995-06-22 Solvay Interox Process for bleaching a chemical paper pulp
US5698075A (en) * 1991-03-11 1997-12-16 Solvay Interox (Societe Anonyme) Process for bleaching a chemical paper pulp in an oxygen-peroxymonosulfuric acid-hydrogen peroxide sequence
EP0560421A1 (fr) * 1992-03-09 1993-09-15 SOLVAY INTEROX (Société Anonyme) Procédé pour la décoloration et le blanchiment de vieux papiers colorés

Also Published As

Publication number Publication date
TNSN86016A1 (fr) 1990-01-01
BR8600421A (pt) 1986-10-14
PH21180A (en) 1987-08-07
ZA86598B (en) 1987-01-28
ES551586A0 (es) 1987-04-16
FR2576930A1 (fr) 1986-08-08
PT81909B (fr) 1987-05-13
PT81909A (fr) 1986-02-01
ES8802335A1 (es) 1987-04-16
IN164977B (enrdf_load_stackoverflow) 1989-07-15
EG17850A (en) 1991-11-30
FR2576930B1 (fr) 1988-08-12
JPS61179390A (ja) 1986-08-12
AU5293886A (en) 1986-08-07
CN86101158A (zh) 1986-07-30

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