EP0351330B1 - Procédé de fabrication de pâtes chimicothermomécaniques blanchies - Google Patents
Procédé de fabrication de pâtes chimicothermomécaniques blanchies Download PDFInfo
- Publication number
- EP0351330B1 EP0351330B1 EP89420245A EP89420245A EP0351330B1 EP 0351330 B1 EP0351330 B1 EP 0351330B1 EP 89420245 A EP89420245 A EP 89420245A EP 89420245 A EP89420245 A EP 89420245A EP 0351330 B1 EP0351330 B1 EP 0351330B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- weight
- process according
- treatment
- bleaching
- sodium
- 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
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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
- D21C3/00—Pulping cellulose-containing materials
- D21C3/04—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides
- D21C3/06—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides sulfur dioxide; sulfurous acid; bisulfites sulfites
-
- 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
Definitions
- the invention relates to the manufacture of bleached chemothermal-mechanical pulps.
- CTMP pasta means pasta which result from application to a lignocellulosic material, generally wood in the form of chips, treatment using one or more chemical agents combined with heating and mechanical defibration operations.
- CTMP pasta is of definite industrial interest because they make an interesting compromise between pasta mechanical and chemical pulps themselves.
- treatment can take place before, during or after defibration.
- treatment is meant here and in all that follows, the operation during which the lignocellulosic material is present with a sulfite, in practice sodium sulfite Na 2 SO 3 , or a bisulfite, in practice sodium bisulfite NaHSO 3 , or more generally a mixture of sulfur dioxide SO 2 and sodium hydroxide NaOH, at a temperature equal to or greater than 100 ° C., under saturated steam pressure, said sulfite, bisulfite or mixture being indifferently designated by sulfite in all that follows.
- the treatment includes, where appropriate, a conventional impregnation of the lignocellulosic material using a solution of the selected reagents.
- the temperature at which the treatment is carried out generally does not exceed 200 ° C and is preferably included between about 120 ° C and 160 ° C.
- the treatment medium generally has an initial pH preferably chosen between 6 and 12.5.
- Consistency weight concentration in paste expressed in the dry state in the medium, is, in the treatment, for example between 10% and 40%, most often between 15% and 30%.
- the duration of treatment depends on the choice of others parameters but generally does not exceed 1 hour.
- the amount of sulfite is for example between about 0.1% and 10%, most often between 0.5% and 3%, the percentages being given by weight relative to the weight of the lignocellulosic material considered. in the dry state, as will be the case, unless specified or obvious, for the percentages of material in all that follows.
- Chemical agents can be used in the treatment at the same time as sulfite, such as complexing or sequestering agents such as diethylenetriaminepentaacetic acids (DTPA) or ethylenetriaminetraacetic (EDTA) used in the form of sodium salts in quantity generally between about 0.1% and 1%.
- complexing or sequestering agents such as diethylenetriaminepentaacetic acids (DTPA) or ethylenetriaminetraacetic (EDTA) used in the form of sodium salts in quantity generally between about 0.1% and 1%.
- CTMP pasta for example from the work of James P. CASEY, PULP & PAPER CHEMISTRY & CHEMICAL TECHNOLOGY, 3rd edition, vol.I, 1980, in particular pages 241-245, 213-219-229, to the work PULP & PAPER MANUFACTURE, VOL. 2, 1987 - MECHANICAL PULPING -, in particular chapters VIII D and XI, or even to the patent of United States of America No. 4718980 in particular Figure 1.
- bleached CTMP pulps here the CTMP pulps defined above, after they have been bleached using hydrogen peroxide H 2 O 2 in an alkaline medium.
- the dough before being bleached with hydrogen peroxide, must as far as possible be free of chemical agent (s) such as sulfite ions, which it is known that they must cause consumption of H 2 O 2 harmful to bleaching, as indicated for example by H.KRUGER, HUSUSS, TAPPI PROCEEDINGS, 1982 INTERNATIONAL SULFITE PULPING CONFERENCE, 143-148.
- chemical agent such as sulfite ions
- Bleaching of CTMP pulp with peroxide of hydrogen in an alkaline medium is usually carried out and engaging an amount of hydrogen peroxide between approximately 0.5% and 10%, in the presence of approximately 1% to 6% of a 1.33 density sodium silicate solution, including pH between about 9 and 11, at a temperature between about 40 ° C and 100 ° C for about 0.5 to 2 hours, with a consistency between about 10% and 30%.
- the bath of bleaching may contain additives such as mainly a or more sequestering or complexing agents, such as example DTPA, in an amount generally between about 0.1% and 1%.
- the dough is preferably treated with an acid such as SO 2 to stabilize its whiteness, before being diluted with water to a very low consistency, for example of the order of 1%, to allow its transfer. , its storage and its use in stationery.
- an acid such as SO 2
- Aqueous effluents mainly from washing, classification, water separation operations final dilution before or during papermaking depending on whether this manufacturing is integrated into manufacturing or not of dough, which contains practically no more sulfite but a still high polluting load, are necessarily recycled and in particular serve as a washing agent for the paste to remove sulfite before bleaching with hydrogen peroxide.
- the present invention avoids the disadvantages above industrial technique known for make bleached CTMP pasta, without the level of white of this pasta is felt, on the contrary.
- CTMP chemothermal mechanical pulps
- said treatment possibly taking place before, during or after defibration and consisting of the action of a sulfite chosen from sodium sulfite, sodium bisulfite, a mixture of sulfur dioxide and sodium hydroxide, at a temperature equal to or greater than 100 ° C., under saturated steam pressure, the CTMP paste thus obtained is then bleached with hydrogen peroxide in an alkaline medium, characterized in that no solid matter or any material liquid are eliminated from the start of said treatment until the end of said bleaching. All that has been stated above applies to the definition of the invention, with the exception of what, after refining, affects, prior to bleaching, washing operations, classification and reconcentration of the dough. which no longer take place.
- a lag time of between 5 and 30 minutes at the outlet temperature of the refiner allows the completion of the treatment.
- the reducing agent is most often chosen from thiourea dioxide or formamidinesulfinic acid, sodium hydrosulfite or dithionite, and sodium borohydride.
- the quantity of reducing agent used may vary depending on the nature of it. It is generally understood, for the first two cited between approximately 0.1% and 5% and between about 0.01% and 0.5% for the third which is conveniently used in the form of an aqueous solution as by example the solution containing 12% by weight of sodium borohydride and marketed under the name of BOROL® by the company VENTRON Corporation.
- the invention finds all its interest in practice when it is aimed at obtaining CTMP pulps bleached up to a high degree of white, for example 80 ° and more when it is measured in the usual way today at the length d wave of 457 nm with magnesium oxide as a reference standard using the spectrophotometer of the General Electric or Elrepho type.
- the amount of sulfite expressed as SO 2 2 is then preferably between approximately 0.5% and 3% and the amount of hydrogen peroxide preferably between 3% and 10%, most often between 4% and 6% .
- Another object of the invention is a method according to the invention in which the bleached CTMP pulp is refined straight out of laundering. This refinement is performed at atmospheric pressure.
- the advantage reported by the U.S. Patent No. 4,718,980 in Case only mechanical and thermomechanical pastes is thus preserved in the case of CTMP pulp whitened without then have to thicken the dough.
- the invention is therefore also a manufacturing process bleached CTMP pasta, as previously presented from said invention, characterized in that the bleached CTMP pulp is refined directly after bleaching and therefore in that it is not removed from solid or liquid matter from the dough from the start of processing to the end of refining after bleaching.
- the classification can thus be carried out on dough bleached and refined. Dilute with clear industrial water and recycle classification refusals to the pulp refiner bleached is then done without inconvenience.
- the method of the invention in which there is no to reheat the dough, allows to dispense with a contribution of calories from a source outside the system provided that the conservation of calories in the system is sufficient well insured.
- the process of the invention compared to known techniques, therefore saves mechanical as well as thermal energy.
- the invention applies to soft wood or coniferous, like hardwood or hardwood.
- Figure 1 is a diagram of a sequence of such operations according to a mode which one can hold as preferred.
- Figure 2 is a diagram illustrating an example of the known technique as it is commonly adopted.
- wood chips usually washed, are conveyed from the feed hopper 101 to 102, chip preheating chamber at the water vapor introduced by 103, from where they exit to pass with the solution of the reagents introduced by 104, in the refiner 105 then in cyclone 106 from where water vapor is separated by 107.
- the dough passes through the latency zone 108 before being intimately mixed with the bleaching reagents supplied by 109, to be bleached in the bleaching tower 110.
- the bleached pulp coming out of 110 is directly fed into the refiner at atmospheric pressure 111 where it comes from to be classified in 112 after dilution with clear industrial water introduced by 113.
- Classification refusals sufficiently refocused, are refined separately (circuit not shown) or recycled by 114 to the entrance to the refiner 111.
- the dough is acidified with known manner and sent to storage 115 and / or to the papermaking by 116.
- the additional means 217 is a thickening, reconcentration equipment dough between its classification in 212 and its bleaching in 210.
- the aqueous effluent collected from 217 by 218 contributes to form clear industrial water which is introduced par 213 to serve as a paste washing agent.
- Softwood shavings are refined under saturated steam pressure at 120 ° C with 2.75% Na 2 SO 3 to yield a paste with a white degree of 57 °.
- This pulp is bleached, without removing any liquid or solid material, using H 2 O 2 : 5%, NaOH: 2%, silicate: 4%, DTPA: 0.5%, for 2 hours at 90 ° C at a consistency of 15%.
- the bleached pulp obtained has a degree of whiteness of 77.9 °.
- a mechanical pulp of a softwood wheel is subjected to a pressure treatment of saturated steam at 120 ° C with 2.75% Na 2 SO 3 and 0, 5% DTPA for 30 minutes at a consistency of 20%, before being bleached directly, without elimination of solid or liquid material, as in Example 1.
- the bleached pulp obtained has a degree of white equal to 78.7 °
- the dough is bleached after washing with water industrial white as in example 1 its degree of white is 78.6 ° and is still lower, at most equal to that achieved by operating according to the invention.
- Example 2 and the comparison it includes, is repeated with the difference that 1% of BOROL® is present with sulfite.
- the degree of white of the bleached pulp is equal to 82.2 ° while it is only 80.9 ° in the comparison.
- the whiteness of the bleached dough is only 1 ° to that achieved by proceeding according to the invention.
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
- Thermotherapy And Cooling Therapy Devices (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Seasonings (AREA)
- Adhesives Or Adhesive Processes (AREA)
- Glass Compositions (AREA)
- Preparation Of Compounds By Using Micro-Organisms (AREA)
Description
- la production d'une quantité très importante d'effluents aqueux, environ 100 tonnes par tonne de papier,
- la reconcentration nécessaire de la pâte avant blanchiment, qui implique l'usage d'un appareillage coûteux, filtre pour pâte ou presse par exemple, au moyen duquel il reste malgré tout difficile d'atteindre une consistance élevée dont il est connu qu'elle favorise l'action du peroxyde d'hydrogène.
Tout ce qui a été énoncé plus avant s'applique à la définition de l'invention, à l'exception de ce qui, après raffinage, touche, en amont du blanchiment, aux opérations de lavage, de classage et de reconcentration de la pâte qui n'ont plus lieu. Lorsque le traitement est effectué pendant l'opération du raffinage, un temps de latence d'une durée comprise entre environ 5 et 30 minutes à la température de sortie du raffineur permet l'achèvement du traitement.
C'est même alors le mode préféré de réalisation du traitement dans le procédé de l'invention.
- les quantités, comme cela a déjà été signalé, sont exprimées en % en poids par rapport à la matière lignocellulosique prise à l'état sec, sauf précision,
- par DTPA est désignée une solution aqueuse à 40 % en poids de sel de sodium de l'acide diéthylènetriaminepentaacétique et la quantité de DTPA est celle de cette solution,
- par lavage est désignée l'opération combinant dilution et pressage de la pâte,
- le borohydrure de sodium est appliqué sous forme de BOROL® et la quantité indiquée est celle de cette présentation,
- par silicate est désignée une solution aqueuse de silicate de sodium de densité égale à 1,33,
- le degré de blanc est mesuré à la longueur d'onde de 457 nm avec l'oxyde de magnésium comme standard de référence à l'aide d'un spectrophotomètre de type ELREPHO fabriqué par KARL ZEISS.
Claims (10)
- Procédé de fabrication de pâtes chimicothermomécaniques (CTMP) blanchies à partir d'une matière lignocellulosique, généralement du bois sous forme de copeaux, cette matière étant soumise à un défibrage et à un traitement chimique pour donner une pâte CTMP, ledit traitement pouvant avoir lieu avant, pendant ou après le défibrage et consistant en l'action d'un sulfite choisi parmi le sulfite de sodium, le bisulfite de sodium, un mélange de dioxyde de soufre et l'hydroxyde de sodium, à une température égale ou supérieure à 100°C, sous pression de vapeur d'eau saturée, la pâte CTMP ainsi obtenue étant ensuite blanchie à l'aide de péroxyde d'hydrogène en milieu alcalin, caractérisé en ce qu'aucune matière solide ni aucune matière liquide ne sont éliminées depuis le début dudit traitement jusqu'à la fin dudit blanchiment.
- Procédé suivant la revendication 1, caractérisé en ce que la quantité de sulfite exprimée en dioxyde de soufre en poids par rapport au poids de la matière lignocellulosique considérée à l'état sec, est comprise entre 0,5% et 3 %.
- Procédé suivant la revendication 1 ou 2, caractérisé en ce qu'un agent plus électronégatif que l'ion sulfite est présent dans le traitement en même temps que le sulfite.
- Procédé suivant la revendication 3, caractérisé en ce que l'agent est choisi parmi le dioxyde de thiourée, le borohydrure de sodium et le dithionite de sodium.
- Procédé suivant la revendication 4, caractérisé en ce que la quantité de dioxyde de thiourée ou de dithionite de sodium est comprise entre 0,1% et 5% au poids par rapport au poids de la matière lignocellulosique considérée à l'état sec.
- Procédé suivant la revendication 4, caractérisé en ce que la quantité de borohydrure de sodium est comprise entre 0,01% et 0,5% en poids par rapport au poids de la matière lignocellulosique considérée à l'état sec.
- Procédé suivant l'une des revendications 1 à 6, caractérisé en ce que dans le traitement le pH initial est compris entre 6 et 12,5.
- Procédé suivant la revendication 1 à 7, caractérisé en ce que la quantité de péroxyde d'hydrogène dans le blanchiment est comprise entre 3% et 10% en poids par rapport au poids de la matière lignocellulosique considérée à l'état sec.
- Procédé suivant la revendication 8, caractérisé en ce que la quantité de péroxyde d'hydrogène est comprise à 4 % et 6% en poids par rapport au poids de la matière lignocellulosique considérée à l'état sec.
- Procédé suivant l'une des revendications 1 à 9, caractérisé en ce que la pâte CTMP blanchie est raffinée directement après le blanchiment sans qu'aucune matière solide, ni aucune matière liquide ne soient éliminées depuis le début dudit traitement jusqu'à la fin du raffinage après blanchiment.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR8809703A FR2634233B1 (fr) | 1988-07-12 | 1988-07-12 | Procede de fabrication de pates chimicothermomecaniques blanchies |
FR8809703 | 1988-07-12 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0351330A1 EP0351330A1 (fr) | 1990-01-17 |
EP0351330B1 true EP0351330B1 (fr) | 1998-09-30 |
Family
ID=9368520
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP89420245A Expired - Lifetime EP0351330B1 (fr) | 1988-07-12 | 1989-07-06 | Procédé de fabrication de pâtes chimicothermomécaniques blanchies |
Country Status (12)
Country | Link |
---|---|
EP (1) | EP0351330B1 (fr) |
JP (1) | JPH0268377A (fr) |
AT (1) | ATE171741T1 (fr) |
AU (1) | AU616541B2 (fr) |
CA (1) | CA1335406C (fr) |
DE (2) | DE351330T1 (fr) |
ES (1) | ES2012324T3 (fr) |
FI (1) | FI96522C (fr) |
FR (1) | FR2634233B1 (fr) |
NO (1) | NO176726C (fr) |
NZ (1) | NZ229902A (fr) |
PT (1) | PT91128B (fr) |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2615874B1 (fr) * | 1987-05-25 | 1992-02-21 | Atochem | Procede de preparation de pates chimicothermomecaniques |
FR2675518B1 (fr) * | 1991-04-17 | 1996-10-18 | Atochem | Procede de preparation de pate a papier a haut rendement et blanchie, a partir de copeaux de bois. |
US20030062138A1 (en) * | 2001-05-09 | 2003-04-03 | Hache Maurice Joseph Albert | Method for brightening mechanical pulps |
JP4501329B2 (ja) * | 2002-03-29 | 2010-07-14 | 日本製紙株式会社 | グラビア印刷用塗工紙 |
BRPI0810574B1 (pt) * | 2007-04-24 | 2018-10-23 | Basf Se | processos para a produção de partículas de madeira branqueada, e para a produção de materiais baseados em madeira clara a branca |
US9932709B2 (en) | 2013-03-15 | 2018-04-03 | Ecolab Usa Inc. | Processes and compositions for brightness improvement in paper production |
US20100224333A1 (en) * | 2009-03-09 | 2010-09-09 | Prasad Duggirala | Method and chemical composition to improve efficiency of mechanical pulp |
EP2924166A1 (fr) * | 2014-03-25 | 2015-09-30 | Basf Se | Procédé de fabrication de fibre de bois blanchie |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE834808C (de) * | 1950-08-31 | 1952-03-24 | Degussa | Verfahren zum Bleichen von mechanisch erzeugten, schwer bleichbaren Faserstoffen, insbesondere Holzschliff |
US3284283A (en) * | 1964-02-17 | 1966-11-08 | Fmc Corp | Production of wood pulps including treatment of cellulosic fibers with bisulfite ion followed by alkali metal borohydride |
SE416481B (sv) * | 1977-05-02 | 1981-01-05 | Mo Och Domsjoe Ab | Fofarande och anordning for behandling av vedflis for avlegsnande av tungmetaller och harts |
CA1212505A (fr) * | 1984-07-17 | 1986-10-14 | Rudy Vit | Methode et installation de conversion du bois, des residus du bois et de la biomasse et pate |
US4718980A (en) * | 1985-12-30 | 1988-01-12 | Weyerhaeuser Company | Interstage treatment of mechanical pulp |
FR2615874B1 (fr) * | 1987-05-25 | 1992-02-21 | Atochem | Procede de preparation de pates chimicothermomecaniques |
SE460124B (sv) * | 1988-09-14 | 1989-09-11 | Sunds Defibrator | Saett foer framstaellning av kemimekanisk massa av loevved |
-
1988
- 1988-07-12 FR FR8809703A patent/FR2634233B1/fr not_active Expired - Fee Related
-
1989
- 1989-07-06 AT AT89420245T patent/ATE171741T1/de not_active IP Right Cessation
- 1989-07-06 NO NO892805A patent/NO176726C/no unknown
- 1989-07-06 DE DE198989420245T patent/DE351330T1/de active Pending
- 1989-07-06 EP EP89420245A patent/EP0351330B1/fr not_active Expired - Lifetime
- 1989-07-06 DE DE68928822T patent/DE68928822T2/de not_active Expired - Fee Related
- 1989-07-06 ES ES89420245T patent/ES2012324T3/es not_active Expired - Lifetime
- 1989-07-11 NZ NZ229902A patent/NZ229902A/xx unknown
- 1989-07-11 CA CA000605392A patent/CA1335406C/fr not_active Expired - Fee Related
- 1989-07-11 AU AU37999/89A patent/AU616541B2/en not_active Ceased
- 1989-07-11 FI FI893372A patent/FI96522C/fi not_active IP Right Cessation
- 1989-07-11 PT PT91128A patent/PT91128B/pt not_active IP Right Cessation
- 1989-07-12 JP JP1180113A patent/JPH0268377A/ja active Granted
Non-Patent Citations (3)
Title |
---|
International Sulfite Pulping Conference 1982; Tappi Proceedings; H.Krüger et al; Bleaching of sulfite pups with peroxide and oxygen, possibilities and limitation, Tappi proceedings, pages 143 * |
The Joint Textbook Committee of the Paper Industry, Pulp and Paper Manufacture; Vol. 2; Third Edition, 1987; R.Barton et al; Mechanical Pulping; pages 99-111, 155, 157 * |
TMP Survey, Pulp & Paper, July 1978, pages 99-110 * |
Also Published As
Publication number | Publication date |
---|---|
JPH0268377A (ja) | 1990-03-07 |
JPH0250236B2 (fr) | 1990-11-01 |
NO892805D0 (no) | 1989-07-06 |
CA1335406C (fr) | 1995-05-02 |
AU616541B2 (en) | 1991-10-31 |
ES2012324T3 (es) | 1998-11-16 |
FI96522C (fi) | 1996-07-10 |
FR2634233B1 (fr) | 1995-04-14 |
PT91128B (pt) | 1994-12-30 |
NO176726C (no) | 1995-05-16 |
ES2012324A4 (es) | 1990-03-16 |
NO892805L (no) | 1990-01-15 |
FI893372A0 (fi) | 1989-07-11 |
FR2634233A1 (fr) | 1990-01-19 |
DE68928822T2 (de) | 1999-05-27 |
FI96522B (fi) | 1996-03-29 |
AU3799989A (en) | 1990-01-18 |
ATE171741T1 (de) | 1998-10-15 |
DE68928822D1 (de) | 1998-11-05 |
FI893372A (fi) | 1990-01-13 |
EP0351330A1 (fr) | 1990-01-17 |
NO176726B (no) | 1995-02-06 |
DE351330T1 (de) | 1990-06-13 |
PT91128A (pt) | 1990-02-08 |
NZ229902A (en) | 1991-09-25 |
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GBC | Gb: translation of claims filed (gb section 78(7)/1977) | ||
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