EP0801169B1 - Verfahren zur Entfernung von Lignin aus Chemie-Papierzellstoffen und zur Bleichung dieser Zellstoffe. - Google Patents

Verfahren zur Entfernung von Lignin aus Chemie-Papierzellstoffen und zur Bleichung dieser Zellstoffe. Download PDF

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EP0801169B1
EP0801169B1 EP97400497A EP97400497A EP0801169B1 EP 0801169 B1 EP0801169 B1 EP 0801169B1 EP 97400497 A EP97400497 A EP 97400497A EP 97400497 A EP97400497 A EP 97400497A EP 0801169 B1 EP0801169 B1 EP 0801169B1
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process according
pulp
temperature
pressure
treatment
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EP0801169A1 (de
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Michel Devic
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Arkema France SA
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Atofina SA
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    • 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
    • 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

  • the present invention relates to a method of delignification and bleaching of chemical paper pulp.
  • Chemical paper pulps or chemical pulps are those obtained by cooking lignocellulosic materials, in particular wood, in the presence chemical agents such as sodium hydroxide for KRAFT pastes, sulfite or bisulfite.
  • wood can be used.
  • softwoods such as various species of pines and fir trees
  • hardwoods such as birch, poplar, beech and eucalyptus.
  • the chemical pastes obtained by cooking are subjected to several stages of delignifying treatments and / or bleaching.
  • the first steps of perfecting the delignification resulting from cooking are followed by those of bleaching.
  • the pasta After these delignifying and bleaching treatments, the pasta generally have a high whiteness level, a very high Kappa index weak while retaining good mechanical properties, i.e. without significant degradation of cellulose. This deterioration is detectable by the measurement of the degree of polymerization (DP) of the dough.
  • the PD must remain as high as possible.
  • delignification and bleaching including a step of treatment by hydrogen peroxide in the presence of the alkali metal silicate at a temperature T greater than 100 ° C and at a pressure greater than 1.5 times the pressure of the saturated water vapor at temperature T.
  • the presence of silicate is necessary to obtain a paste delignified and having both a high level of whiteness and a DP.
  • the plaintiff has discovered a new process for delignification and simultaneous bleaching with hydrogen peroxide of a chemical pulp, making it possible to obtain a highly bleached pulp and having retained a good degree of polymerization.
  • This process is characterized in that after pretreatment with a complexing or sequestering agent of transition metals, in particular manganese, it comprises one or more step (s) in which the dough undergoes a treatment with hydrogen peroxide to a temperature T greater than 100 ° C., at a pressure greater than 1.5 times the saturated water vapor pressure at temperature T, in the presence of a polymer comprising units of formula (I) and / or (II ): in which R 1 and R 2 , identical or different, each represent a hydrogen atom or an alkyl group comprising from 1 to 3 carbon atoms and M represents a hydrogen atom, an ammonium group or an alkali or alkaline metal earthy, and in the presence of a compound A chosen from potassium hydroxide, sodium hydroxide, alkali or alkaline earth metal carbonates.
  • a complexing or sequestering agent of transition metals in particular manganese
  • these salts the potassium, sodium, magnesium and calcium salts are advantageously chosen.
  • the average molecular weight of the polymer comprising units of formula (I) and / or formula (II) is generally between 1,000 and 800,000 and preferably between 2,000 and 100,000.
  • the polymer comprising units of formula (I) and / or of formula (II) is known as stabilizing agent for peroxide solutions (GB 1 524 013, FR 2 601 025). It can be prepared using the methods described in the FR 2 237 914, FR 2 237 916 and FR 2 628 745.
  • Compound A is advantageously chosen from carbonates, such as sodium carbonate, potassium carbonate, magnesium carbonate and calcium carbonate, because the process according to the present invention offers in this variant the advantage of not producing any liquid effluent (TEF, Totally Effluent Free). So after evaporation of the washing water (washing is described below) and incineration of organic matter, we easily regenerate the alkali or alkaline earth metal carbonate, without the need for a caustification by lime.
  • TEZ liquid effluent
  • sodium carbonate is used.
  • the consistency of the dough is expressed in percent by weight of material dry relative to the total weight of the dough.
  • the amount of polymer used is generally between about 0.05% and about 1.5%, preferably between about 0.1% and approximately 1% and more particularly between approximately 0.2% and approximately 0.5%.
  • compound A is used at a rate of 1 to 15% and preferably from 6 to 10 % for carbonates.
  • the amount of hydrogen peroxide used can vary from 0.5 to about 10%.
  • a quantity of hydrogen peroxide is used between approximately 1 and approximately 4% and very particularly between approximately 1.5 % and about 2.5%.
  • a sequestering agent such as DTPA (diethylenetriaminepentaacetate sodium) or EDTA (sodium ethylenediaminetetraacetate) and preferably amount less than 0.2%.
  • the paste before treatment with peroxide of hydrogen, can be subjected to one or more delignification stage (s) by ozone and / or chlorine dioxide and / or organic or mineral peracids and / or oxygen, known from the paper industry. We prefer to use oxygen.
  • the dough can be washed one or several times in hot or cold water.
  • the transition metal complexing or sequestering agent used in the pretreatment can be chosen from DTPA, EDTA, acids phosphonic or the salts of phosphonic acids. We can also combine several agents to increase the effectiveness of the pretreatment vis-à-vis of more metals.
  • the amount of complexing or sequestering agent is generally understood between about 0.05% and about 1%. We prefer to use a quantity included between about 0.1% and about 0.5%.
  • the pre-treatment temperature is generally 20 to 100 ° C and preferably between about 60 and about 90 ° C.
  • the duration of the pretreatment with the complexing agent is generally from 1 to 30 minutes and preferably 5 to 15 minutes.
  • the consistency of the dough during pretreatment may vary within limits ranging from 1 to 25%. A consistency of between 5 and 15% is preferred.
  • the pretreatment with the complexing agent can be carried out in medium at acidic pH, it is preferable to operate at basic pH.
  • the pH is greater than 7 and less than or equal to 12.5.
  • a pH between 8 and 10 is particularly preferred.
  • the alkaline pH during pretreatment can be obtained either by alkalinity residual pulp at the end of the oxygen treatment, i.e. by the alkalinity of the complexing or sequestering agent, or again by the addition of a base such as NaOH.
  • the manganese content of the dough before treatment with hydrogen peroxide does not exceed 5 ppm by weight relative to the weight of the dry matter of this same paste.
  • the paste is washed with water. Washing can be carried out according to techniques known in the paper industry with hot or cold water.
  • the peroxide is added of hydrogen, compound A, the polymer comprising units of formula (I) and / or (II) and possibly water so as to obtain the chosen consistency, then the mixture is subjected to a pressure greater than 1.5 times the pressure of the saturated water vapor at treatment temperature T and then the mixing at temperature T.
  • the reagents are added to the paste preferably at room temperature or at a temperature below about 60 ° C.
  • the devices generally used in the paper industry for the cooking the pasta and allowing the dough to remain impregnated with the solution aqueous hydrogen peroxide, compound A and polymer at a pressure and at a high temperature for the selected time may be suitable for the implementation of the treatment step with hydrogen peroxide, according to the invention.
  • the dough is decompressed, possibly cooled then washed with water to remove all organic matter and soluble minerals.
  • the wash water can then be concentrated by evaporation then incinerated in a boiler using standard industry techniques paper mill.
  • the ash obtained consists mainly of carbonate recyclable after purification.
  • the consistency of the paste, when treated with hydrogen peroxide is generally between about 4 to 35%.
  • the process can be carried out effectively at low consistency about 4 to about 10% and the medium reaction can be easily transferred by pumping.
  • a consistency of the dough between about 15 and about 25% achieves high levels of whiteness and delignification while saving heating energy.
  • a consistency of between approximately 8 and around 20% is advantageously chosen because it optimizes the process yield.
  • the pressure to which the dough is subjected generally reaches a value greater than 1.5 times the pressure of the saturated water vapor at temperature T treatment with hydrogen peroxide before the temperature of the medium exceeds 100 ° C.
  • the pressure is greater than 2 times the pressure of saturated water vapor at treatment temperature T.
  • a pressure of between 5 and 200 bars is used absolute.
  • the pressure is preferably between 5 and 50 bars absolute.
  • a pressure between 5 and 20 bar absolute is economically preferred.
  • the dough can be pressurized by any means suitable for obtaining a pressure greater than 1.5 times the pressure of saturated water vapor at treatment temperature T. So this pressure can be established using a compressed gas such as air or nitrogen. She can also be obtained by pumping the dough with a centrifugal pump or high pressure volumetric in a closed enclosure.
  • the reaction temperature T is most often between 110 and 180 ° C and advantageously from 120 to 150 ° C.
  • Treatment with hydrogen peroxide generally lasts for 1 minute to 3 hours.
  • the duration varies inversely with the increase in temperature.
  • Preferably the duration is from 15 minutes to 1 hour.
  • the dough may undergo a second stage of treatment under the same conditions as above or under usual conditions (temperature below 90 ° C, pressure atmospheric, alkaline medium in the presence of either magnesium sulfate or sodium silicate) or it can be treated with chlorine dioxide in known conditions in the paper industry.
  • the dough after cooking and possibly after delignification by oxygen, is suspended at 10% consistency with 0.5% of a commercial solution at 40% by weight of DTPA and heated to 15 minutes at 90 ° C.
  • the final pH is 8 to 10 depending on the paste chosen.
  • the dough is then filtered and washed with demineralized water.
  • Aqueous solution of hydrogen peroxide, compound A, acid poly- ⁇ -hydroxyacrylic or the corresponding polylactone and demineralized water necessary to obtain the chosen consistency, are added to the dough collected in at). Then the reaction medium thus obtained is placed in a steel autoclave stainless steel. Fully filled autoclave is pressurized with air compressed and then heated to the temperature T chosen for the duration chosen. To to maintain the pressure at the selected reaction value, we open by the autoclave degassing valve intermittently.
  • the autoclave After reaction, the autoclave is cooled and then decompressed, the dough is collected on a filter and washed with demineralized water. We then perform the whiteness, Kappa index and DP measurements according to the paper industry.
  • the washing water can be concentrated by evaporation and then cremated. Ashes consisting mainly of sodium carbonate can be recycled.
  • the amounts of reagents are expressed in for hundred by weight relative to the weight of the dry matter of the dough and the pressures are, unless otherwise indicated, expressed in relative pressure.
  • KF1 KRAFT hardwood pulp
  • the pH of the dough after the pretreatment is 9.5. At the end of the treatment 99% of the hydrogen peroxide was consumed and the final pH was 9.4.
  • the degree of whiteness of the dough is 73.7 ° ISO, the Kappa index is 7.4 and the degree of polymerization (DP) is 1500.
  • Example 2 The procedure is identical to Example 1 but in the absence of the acid poly- ⁇ -hydroxyacrylic and / or corresponding polylactone. The degree of whiteness is then equal to ISO 60.8 °, the Kappa index is 8 and the DP is 1100.
  • Example 2 The procedure is identical to Example 1 except that the amount of polylactone varies.
  • Example 2 The procedure is identical to Example 1 except that the amount of sodium carbonate varies.
  • Table I summarizes the characteristics of the paste obtained at the end of the tests of Examples 1 to 13.
  • Figures 1-3 show the beneficial effect of sodium carbonate and polylactone on the whiteness and the degree of polymerization of the paste KF1.
  • the dough After pretreatment with the complexing agent, the dough is bleached in the conditions recorded in table II.
  • Example 18 8% of a commercial silicate solution is used sodium (density 1.33) instead of carbonate and poly- ⁇ -hydroxyacrylic acid.
  • Example 19 is not in accordance with the invention, since a pressure equal to the saturated water vapor pressure at the process temperature was applied.
  • Example 21 not in accordance with the invention, was carried out in the absence of polymer.
  • Examples 25 and 26 are comparative tests with the use of soda and silicate or soda and magnesium sulfate in place of sodium carbonate and polylactone.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Claims (12)

  1. Verfahren zur Entfernung von Lignin aus einem Chemiezellstoff und zur Bleichung dieses Zellstoffs, dadurch gekennzeichnet, daß es nach einer Vorbehandlung mit einem Komplexierungsmittel oder Sequestrierungsmittel für Übergangsmetalle einen oder mehrere Schritte umfaßt, in dem oder denen der Zellstoff einer Behandlung mit Wasserstoffperoxid bei einer Temperatur T oberhalb von 100 °C bei einem Druck, der größer als das 1,5-fache des Sättigungsdampfdrucks von Wasser bei der Temperatur T ist, in Gegenwart eines Polymers, das Einheiten der Formel (I) und/oder Formel (II)
    Figure 00190001
    Figure 00190002
    enthält, worin R1 und R2, die gleich oder verschieden sind, jeweils ein Wasserstoffatom oder eine Alkylgruppe mit 1 bis 3 Kohlenstoffatomen darstellen und M ein Wasserstoffatom, eine Ammoniumgruppe, ein Alkalimetall oder Erdalkalimetall bedeutet, und in Gegenwart einer Verbindung A, die unter Kaliumhydroxid, Natriumhydroxid, Alkalimetallcarbonaten und Erdalkalimetallcarbonaten ausgewählt wird, unterzogen wird.
  2. Verfahren zur Entfernung von Lignin aus einem Chemiezellstoff und zur Bleichung dieses Zellstoffs ohne Entstehung Abwässern, dadurch gekennzeichnet, daß es nach einer Vorbehandlung mit einem Komplexierungsmittel oder Sequestrierungsmittel für Übergangsmetalle umfaßt:
    (i) einen oder mehrere Schritte, in dem oder denen der Zellstoff einer Behandlung mit Wasserstoffperoxid bei einer Temperatur T oberhalb von 100 °C bei einem Druck, der größer als das 1,5-fache des Sättigungsdampfdrucks von Wasser bei der Temperatur T ist, in Gegenwart eines Polymers, das Einheiten der Formel (I) und/oder Formel (II)
    Figure 00200001
    Figure 00200002
    enthält, worin R1 und R2, die gleich oder verschieden sind, jeweils ein Wasserstoffatom oder eine Alkylgruppe mit 1 bis 3 Kohlenstoffatomen darstellen und M ein Wasserstoffatom, eine Ammoniumgruppe, ein Alkalimetall oder Erdalkalimetall bedeutet, und in Gegenwart einer Verbindung A, die unter Kaliumhydroxid, Natriumhydroxid, Alkalimetallcarbonaten und Erdalkalimetallcarbonaten ausgewählt wird, unterzogen wird
    (ii) einmaliges oder mehrfaches Waschen des Zellstoffs mit Wasser am Ende dieser Behandlung und
    (iii) Verbrennen des Waschwassers.
  3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der Zellstoff vor der Behandlung mit Wasserstoffperoxid einem oder mehreren Verfahrensschritten, in denen eine Ligninentfernung durchgeführt wird, unterzogen wird.
  4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß das Mittel zur Ligninentfernung unter Sauerstoff, Ozon, organischen und anorganischen Persäuren ausgewählt wird.
  5. Verfahren nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß es sich bei dem Komplexierungsmittel um DTPA handelt.
  6. Verfahren nach Anspruch 5, dadurch gekennzeichnet, daß der pH-Wert des Mediums bei der Vorbehandlung im Bereich von 8 bis 10 liegt.
  7. Verfahren nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß es sich bei der Verbindung A um Natriumcarbonat handelt.
  8. Verfahren nach Anspruch 7, dadurch gekennzeichnet, daß die verwendete Menge an Natriumcarbonat 1 bis 15 %, bezogen auf die Trockensubstanz des Zellstoffs, beträgt.
  9. Verfahren nach einem der Ansprüche 1 bis 8, dadurch gekennzeichnet, daß es sich bei dem Polymer um eine Poly(α-hydroxyacrylsäure), deren Polylacton oder die entsprechenden Salze handelt.
  10. Verfahren nach Anspruch 9, dadurch gekennzeichnet, daß das mittlere Molekulargewicht des Polymers im Bereich von 2 000 bis 100 000 liegt.
  11. Verfahren nach Anspruch 9 oder 10, dadurch gekennzeichnet, daß die verwendete Polymermenge 0,1 bis 1 %, bezogen auf die Masse des Zellstoffs im trockenen Zustand, beträgt.
  12. Verfahren nach einem der Ansprüche 1 bis 11, dadurch gekennzeichnet, daß der Druck des Mediums einen Wert oberhalb des 1,5-fachen des Sättigungsdrucks bei der Temperatur T erreicht, bevor seine Temperatur 100 °C überschreitet.
EP97400497A 1996-04-12 1997-03-04 Verfahren zur Entfernung von Lignin aus Chemie-Papierzellstoffen und zur Bleichung dieser Zellstoffe. Expired - Lifetime EP0801169B1 (de)

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FR9604611 1996-04-12
FR9604611A FR2747407B1 (fr) 1996-04-12 1996-04-12 Procede de delignification et de blanchiment de pates a papier chimiques

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EP0801169A1 EP0801169A1 (de) 1997-10-15
EP0801169B1 true EP0801169B1 (de) 2001-06-20

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US (1) US6554958B1 (de)
EP (1) EP0801169B1 (de)
JP (1) JP3054378B2 (de)
CN (1) CN1085756C (de)
CA (1) CA2200486C (de)
DE (1) DE69705255T2 (de)
ES (1) ES2160300T3 (de)
FR (1) FR2747407B1 (de)
NO (1) NO321519B1 (de)

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FI117393B (fi) 2003-01-10 2006-09-29 Kemira Oyj Menetelmä selluloosakuitumateriaalin valkaisemiseksi
FI120202B (fi) 2003-01-10 2009-07-31 Kemira Oyj Polymeerikoostumus ja sen käyttö
JP4595285B2 (ja) * 2003-02-28 2010-12-08 日本製紙株式会社 未晒クラフトパルプ処理方法および高白色度漂白パルプ製造方法
US20100101743A1 (en) * 2007-02-21 2010-04-29 Solvay (Societe Anonyme) Process for the bleaching of paper pulp
EP2128331A1 (de) * 2008-05-26 2009-12-02 SOLVAY (Société Anonyme) Verfahren zum Bleichen von Papierzellstoff
CN102002876A (zh) * 2010-09-17 2011-04-06 南开大学 一种草类原料无氯无硫清洁制浆方法
EP2726670A4 (de) * 2011-06-30 2015-03-25 Nano Green Biorefineries Inc Katalytische umwandlung von biomasse
BR112018015468A2 (pt) 2016-01-28 2018-12-18 Nano Green Biorefineries Inc produção de celulose cristalina
FR3062138B1 (fr) * 2017-01-23 2019-06-07 Centre Technique De L'industrie Des Papiers, Cartons Et Celluloses Procede de blanchiment d'une pate a papier

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LU74434A1 (de) * 1976-02-25 1977-09-12
US4787959A (en) * 1977-07-29 1988-11-29 Atochem Process for preparing chemical paper pulps by cooking, intermediate grinding and a final alkaline peroxide delignification
US5241026A (en) 1986-07-03 1993-08-31 Sandoz Ltd. Polylactones of poly-α-hydroxyacrylic acid
DE3720806C2 (de) 1986-07-03 1997-08-21 Clariant Finance Bvi Ltd Verwendung eines Stabilisators in Peroxydbleichverfahren
SE466061B (sv) * 1990-04-23 1991-12-09 Eka Nobel Ab Blekning av kemisk massa genom behandling med foerst ett komplexbildande aemne och sedan ett peroxidinnehaallande aemne
CA2063351C (en) * 1992-03-18 1996-08-13 Stanley Alan Heimburger Process for bleaching hardwood pulp
SE500616C2 (sv) * 1993-06-08 1994-07-25 Kvaerner Pulping Tech Blekning av kemisk massa med peroxid vid övertryck
SE501613C2 (sv) * 1993-08-03 1995-03-27 Kvaerner Pulping Tech Sätt vid integrering av blekning och återvinning vid framställning av massa
FR2719854B1 (fr) * 1994-05-11 1996-06-21 Atochem Elf Sa Procédé de préparation de pâtes à papier chimiques délignifiées et blanchies.
FR2719853B1 (fr) 1994-05-11 1996-06-21 Atochem Elf Sa Procédé de délignification et de blanchiment d'une pâte à papier chimique.

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FR2747407B1 (fr) 1998-05-07
EP0801169A1 (de) 1997-10-15
CN1167855A (zh) 1997-12-17
US6554958B1 (en) 2003-04-29
CN1085756C (zh) 2002-05-29
ES2160300T3 (es) 2001-11-01
CA2200486C (fr) 2002-01-15
NO321519B1 (no) 2006-05-15
CA2200486A1 (fr) 1997-10-12
FR2747407A1 (fr) 1997-10-17
JP3054378B2 (ja) 2000-06-19
DE69705255D1 (de) 2001-07-26
NO971407L (no) 1997-10-13
NO971407D0 (no) 1997-03-25
DE69705255T2 (de) 2001-10-11
JPH1025685A (ja) 1998-01-27

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