EP0171575A1 - Process for the delignification and bleaching of cellulose pulps - Google Patents
Process for the delignification and bleaching of cellulose pulps Download PDFInfo
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- EP0171575A1 EP0171575A1 EP85108213A EP85108213A EP0171575A1 EP 0171575 A1 EP0171575 A1 EP 0171575A1 EP 85108213 A EP85108213 A EP 85108213A EP 85108213 A EP85108213 A EP 85108213A EP 0171575 A1 EP0171575 A1 EP 0171575A1
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- Prior art keywords
- oxygen
- hydrogen peroxide
- bleaching
- delignification
- pulp
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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
Definitions
- the invention relates to the delignification of pulps with oxygen and hydrogen peroxide in an acid medium.
- the pulps obtained chemically, e.g. accruing from the sulfite process or the alkaline baking soda or sulfate process contain, in addition to the main component cellulose, small amounts of lignin, hemicelluloses and some other components.
- the accompanying cellulose substances, especially lignin, cause discoloration of the cellulose or of products made from it.
- bleaching is carried out in multi-stage systems with, for example, chlorine, hypochlorite, oxygen and hydrogen peroxide.
- a disadvantage of the use of chlorine and hypochlorite is the formation of chlorinated substances that are difficult to biodegrade and some have mutagenic properties exhibit. Evaporation and combustion of this wastewater is the best way to reduce wastewater problems.
- the recycling of the wastewater from the bleach to the chemical treatment process of the digestion is problematic because of the corrosion caused by chlorine ions.
- Bleaching agents that contain or require neither chlorine ions nor cations such as Na + are therefore desirable for universal use.
- the acid delignification with peroxides preferably hydrogen peroxide
- peroxides preferably hydrogen peroxide
- the acidic treatment is followed by an alkaline extraction step in order to remove the lignin which has become soluble.
- the object of the invention is a method for delignifying and bleaching cellulose, in which a Return of the wastewater from the bleach to the chemical treatment process is possible without any problems.
- the invention relates to a process for the delignification and bleaching of pulps with oxygen and hydrogen peroxide, characterized in that pulp pulps are simultaneously treated with hydrogen peroxide and oxygen at a pH ⁇ 5.
- Sulfite pulps which have been produced using calcium or magnesium sulfite are preferably used.
- the mixture contains oxygen in an amount of 0.1 to 5% by weight and 0.1 to 3% by weight of hydrogen peroxide, based on dry cellulose.
- the process is carried out at 60 to 120 ° C, preferably 80 to 100 ° C, at 2 to 30%, preferably 8 to 15%, consistency and under an oxygen pressure of 0.03 to 0.5 MPa, preferably at 0.3 MPa.
- the most suitable pH range is from 1 to 4, preferably 1.5 to 3.
- the wastewater from the acidic oxygen / peroxide treatment can be recycled without problems in countercurrent to the pulp in the digestion of the cooking acid in the digestion process after the calcium or magnesium sulfite process. If a final bleaching follows the acidic oxygen / peroxide treatment, it is shown as a further advantage that up to 50% of the total wastewater pollution caused by the bleaching and delignification arises in the O / P stage in accordance with the lignin degradation.
- Table 2 compares the COD values (chemical oxygen demand) with a conventional CEHH sequence and those with acidic O / P treatment with a subsequent HH end bleaching process.
- the kappa number was reduced to 8.3 by the O / P stage.
- the values for the final whiteness (R457) are very close at 88.6 (a) and 89.2 (b).
- the strengths also differ very little. With 30 SR, 4.8 km tear length and 820 mNm / m tear strength are obtained, after b) 4.7 km tear length and 830 mNm / m tear strength.
- variant b Since the COD value is decisive for the amount of the wastewater tax to be paid, variant b proves to be more cost-effective. It enables wastewater pollution to be reduced by evaporating and burning the amount of wastewater generated in the acidic O / P stage, in this case by 26.8 kg O 2 / t COD.
- the remaining 43.1 kg O 2 / t COD have a BS B 5 value (biological oxygen demand) of 32.3 kg O 2 / t, so they are 74.9% degradable.
- bleaching sequences such as CD- HD, HHD or PD or HPD, PH, HH can also follow the O / P stage.
- Table 3 shows the results of a further variant.
- the delignification in the O / P stage was almost 50%, a kappa number of 10.5 was determined.
- the strengths of the pulps produced with both sequences differ only slightly; at 30 SR, 6.2 and 6.0 km tear length as well as 1420 and 1480 mNm / m tear tear were determined for a) and b).
- the wastewater load expressed as COD can be reduced by 48.6%, while the wastewater resulting from the bleaching sequence a cannot be reduced in this simple way.
- Table 4 shows the advantages of a combination of the method according to the invention with oxygen delignification in the presence of MgO, which is state of the art. Delignification with oxygen in the presence of Mg0 leads to a lignin breakdown to approx. 60% of the initial value. Subsequent acid treatment with oxygen and hydrogen peroxide reduces the kappa number to 8.2, corresponding to ⁇ 40% of the initial value. Since both the wastewater of the O Mg O and the O / P stage of the evaporation can be fed, a reduction of the COD in the wastewater by over 60% is possible.
- Another preferred embodiment consists in the combination with the delignification in the presence of magnesium oxide, hydrogen peroxide and oxygen in the alkaline range.
- the following example concerns delignification and bleaching of a book sulfite pulp with a kappa number of 16.3:
Abstract
Description
Die Erfindung betrifft die Delignifizierung von Zellstoffen mit Sauerstoff und Wasserstoffperoxid in saurem Medium.The invention relates to the delignification of pulps with oxygen and hydrogen peroxide in an acid medium.
Die auf chemischem Weg gewonnenen Zellstoffe, wie sie z.B. aus dem Sulfitverfahren oder den alkalischen Natron- oder Sulfatverfahren anfallen, enthalten neben dem Hauptbestandteil Cellulose noch geringe Mengen Lignin, Hemicellulosen und einige andere Bestandteile. Die genannten Begleitstoffe der Cellulose, vor allem das Lignin, bewirken die Verfärbung des Zellstoffes oder daraus hergestellter Produkte.The pulps obtained chemically, e.g. accruing from the sulfite process or the alkaline baking soda or sulfate process contain, in addition to the main component cellulose, small amounts of lignin, hemicelluloses and some other components. The accompanying cellulose substances, especially lignin, cause discoloration of the cellulose or of products made from it.
Um aus dem Zellstoff Papier oder andere Produkte von hoher Weiße, die nicht zur Vergilbung neigen, herzustellen, ist eine Entfernung der nach dem chemischen Aufschluß verbliebenen Begleitstoffe durch eine Bleiche notwendig.In order to produce paper or other products of high whiteness, which do not tend to yellowing, it is necessary to remove the accompanying substances which have remained after the chemical digestion by bleaching.
Gemäß Stand der Technik wird die Bleiche in mehrstufigen Systemen mit z.B. Chlor, Hypochlorit, Sauerstoff und Wasserstoffperoxid durchgeführt. Nachteilig ist bei der Anwendung von Chlor und auch Hypochlorit die Bildung chlorierter Substanzen, die biologisch schwer abbaubar sind und teilweise mutagene Eigenschaften aufweisen. Eindampfung und Verbrennung dieser Abwässer ist die beste Methode zur Verringerung der Abwasserprobleme. Die Rückführung des Abwassers aus der Bleiche in den Chemikalienaufbereitungsprozeß des Aufschlusses ist wegen der durch Chlorionen verursachten Korrosion jedoch problematisch.According to the prior art, bleaching is carried out in multi-stage systems with, for example, chlorine, hypochlorite, oxygen and hydrogen peroxide. A disadvantage of the use of chlorine and hypochlorite is the formation of chlorinated substances that are difficult to biodegrade and some have mutagenic properties exhibit. Evaporation and combustion of this wastewater is the best way to reduce wastewater problems. However, the recycling of the wastewater from the bleach to the chemical treatment process of the digestion is problematic because of the corrosion caused by chlorine ions.
Sauerstoff und Wasserstoffperoxid werden heute ausschließlich unter alkalischen Bedingungen als Bleichmittel verwendet. Die Ablauge des Bleichprozesses enthält daher Natronlauge und ist nur bei einem Aufschlußprozeß mit Natrium als Base problemlos zurückzuführen. Bei der Herstellung von Sulfatzellstoff, bei dem mit alkalischer Sulfidlösung gearbeitet wird, ist dies leicht möglich. Die Erzeugung von Sulfit- zellstoff erfolgt dagegen heute fast ausschließlich auf Magnesium- oder Calciumsulfitbasis. Bei der Chemikalienrückgewinnung führt eine Mischung mit Natriumionen zu einer Schmelzpunktserniedrigung im Verbrennungsofen, so daß die Chemikalienrückgewinnung aus der Flugasche und/oder der Wirkungsgrad der Anlage gestört werden. Für Sulfitzellstoffabriken auf Basis Magnesium wurden daher Verfahren entwickelt, die mit Magnesiumoxid als Base arbeiten. Die dazu notwendigen Apparaturen sind jedoch im Vergleich zur Anwendung von Natronlauge deutlich aufwendiger, da höherer Druck und höhere Temperaturen notwendig sind.Today oxygen and hydrogen peroxide are used as bleaching agents only under alkaline conditions. The waste liquor from the bleaching process therefore contains sodium hydroxide solution and can only be easily attributed to a digestion process with sodium as the base. This is easily possible in the production of sulfate pulp, which uses an alkaline sulfide solution. In contrast, sulfite pulp is now almost exclusively based on magnesium or calcium sulfite. In the chemical recovery, a mixture with sodium ions leads to a lowering of the melting point in the incinerator, so that the chemical recovery from the fly ash and / or the efficiency of the plant are disturbed. For magnesium sulfite pulp mills, processes have therefore been developed that work with magnesium oxide as the base. The equipment required for this, however, is significantly more complex compared to the use of sodium hydroxide solution, since higher pressure and higher temperatures are necessary.
Bleichmittel, die weder Chlorionen noch Kationen wie Na+ enthalten oder benötigen, sind daher für eine universelle Anwendung wünschenswert.Bleaching agents that contain or require neither chlorine ions nor cations such as Na + are therefore desirable for universal use.
Dies gilt für Verbindungen wie Ozon, Stickstoffdioxid und Peressigsäure. Die Bleiche und Delignifizierung erfolgt mit diesen Oxidationsmitteln unter sauren Bedingungen, so daß keine Kationen zugesetzt werden müssen. Trotzdem hat sich bisher aus wirtschaftlichen Gründen keines dieser Bleichmittel durchgesetzt.This applies to compounds such as ozone, nitrogen dioxide and peracetic acid. The bleaching and delignification are carried out with these oxidizing agents under acidic conditions, so that no cations have to be added. Nevertheless, none of these bleaching agents has so far been used for economic reasons.
Die saure Delignifizierung mit Peroxiden, bevorzugt Wasserstoffperoxid, betrifft die US-PS 4.222.819 von Fossum et. al. Nach diesem Verfahren schließt sich an die saure Behandlung eine alkalische Extraktionsstufe an, um das löslich gewordene Lignin zu entfernen.The acid delignification with peroxides, preferably hydrogen peroxide, relates to US Pat. No. 4,222,819 by Fossum et. al. After this procedure, the acidic treatment is followed by an alkaline extraction step in order to remove the lignin which has become soluble.
Da unmittelbar anschließend an die saure Behandlung mit Wasserstoffperoxid eine alkalische Behandlung mit Natronlauge folgen muß, entfällt die Möglichkeit einer gemeinsamen Eindampfung des Abwassers der Bleichstufen mit der Ablauge z.B. eines Magnesiumsulfitaufschlusses.Since an alkaline treatment with sodium hydroxide solution must follow immediately after the acidic treatment with hydrogen peroxide, there is no possibility of joint evaporation of the waste water from the bleaching stages with the waste solution, e.g. a magnesium sulfite digestion.
In der US-PS 4 410 397 und der US-PS 4.427.490 wird die Delignifizierung und Bleiche von Zellstoff in sauren Medien beschrieben und der Zusatz von Metalladditiven zur Verbesserung der Wirkung vorgeschlagen..US Pat. Nos. 4,410,397 and 4,427,490 describe the delignification and bleaching of pulp in acidic media and the addition of metal additives to improve the effect.
Es erscheint jedoch nicht sinnvoll, in den Bleichprozeß Schwermetallionen einzuschleusen, die anschließend das Abwasser belasten.However, it does not seem sensible to introduce heavy metal ions into the bleaching process, which then pollute the wastewater.
Aufgabe der Erfindung ist ein Verfahren zum Delignifizieren und Bleichen von Zellstoffen, bei dem eine Rückführung des Abwassers aus der Bleiche in den Chemikalienaufbereitungsprozeß problemlos möglich ist.The object of the invention is a method for delignifying and bleaching cellulose, in which a Return of the wastewater from the bleach to the chemical treatment process is possible without any problems.
Gegenstand der Erfindung ist ein Verfahren zur Delignifizierung und Bleiche von Zellstoffen mit Sauerstoff und Wasserstoffperoxid, dadurch gekennzeichnet, daß man Zellstoffpulpen bei einem pH-Wert <5 gleichzeitig mit Wasserstoffperoxid und Sauerstoff behandelt.The invention relates to a process for the delignification and bleaching of pulps with oxygen and hydrogen peroxide, characterized in that pulp pulps are simultaneously treated with hydrogen peroxide and oxygen at a pH <5.
Bevorzugt eingesetzt werden Sulfitzellstoffe, die unter Verwendung von Calzium- oder Magnesiumsulfit hergestellt wurden.Sulfite pulps which have been produced using calcium or magnesium sulfite are preferably used.
Die Mischung enthält Sauerstoff in einer Menge von 0,1 bis 5 Gew.% und 0,1 bis 3 Gew.-% Wasserstoffperoxid, bezogen auf atro Zellstoff.The mixture contains oxygen in an amount of 0.1 to 5% by weight and 0.1 to 3% by weight of hydrogen peroxide, based on dry cellulose.
Man arbeitet bei 60 bis 120°C, bevorzugt 80 bis 100 °C, bei 2 bis 30 %, bevorzugt8 bis 15 %, Stoffdichte und unter einem Sauerstoffdruck von 0,03 bis 0,5 MPa, bevorzugt bei 0,3 MPa.The process is carried out at 60 to 120 ° C, preferably 80 to 100 ° C, at 2 to 30%, preferably 8 to 15%, consistency and under an oxygen pressure of 0.03 to 0.5 MPa, preferably at 0.3 MPa.
Der geeignetste pH-Bereich reicht von 1 bis 4, bevorzugt 1,5 bis 3.The most suitable pH range is from 1 to 4, preferably 1.5 to 3.
Es zeigt sich, daß das erfindungsgemäße Verfahren zu unerwartet günstigen Ergebnissen führt.It can be seen that the method according to the invention leads to unexpectedly favorable results.
Während die Behandlung von Sulfitzellstoff mit Wasserstoffperoxid im Sauren nur einen begrenzten Erfolg zeitigt, und man auch mit Sauerstoff nur eine geringfügige Delignifizierung erreicht, führt die gemeinsame Anwendung von Sauerstoff und Wasserstoffperoxid zu einer deutlichen Verringerung des Ligningehaltes.While the treatment of sulfite pulp with hydrogen peroxide in acid has only limited success, and only a slight delignification is achieved with oxygen, the combined use of oxygen and hydrogen peroxide leads to a significant reduction in the lignin content.
Mit der von Fossum et al beschriebenen Kombination von saurer und alkalischer Behandlung gelangt man zu diesen günstigen Ergebnissen nicht. Auch die Summierung der mit getrennter Wasserstoffperoxid- und Sauerstoff-Behandlung jeweils erzielbaren Reduzierung von Kappa läßt keine Hinweise auf den mit dem erfindungsgemäßen Verfahren erreichten starken Ligninabbau zu.
Das Abwasser aus der sauren Sauerstoff/Peroxid-Behandlung kann bei Aufschlußverfahren nach dem Calcium-oder Magnesiumsulfitprozeß problemlos im Gegenstrom zum Zellstoff in die Erfassung der Kochsäure zurückgeführt werden. Schließt sich eine Endbleiche an die saure Sauerstoff/Peroxid-Behandlung an, zeigt sich als weiterer Vorteil, daß entsprechend dem Ligninabbau bis zu 50 % der gesamten durch die Bleiche und Delignifizierung verursachten Abwasserbelastung in der O/P-Stufe entsteht.The wastewater from the acidic oxygen / peroxide treatment can be recycled without problems in countercurrent to the pulp in the digestion of the cooking acid in the digestion process after the calcium or magnesium sulfite process. If a final bleaching follows the acidic oxygen / peroxide treatment, it is shown as a further advantage that up to 50% of the total wastewater pollution caused by the bleaching and delignification arises in the O / P stage in accordance with the lignin degradation.
Anhand von Tabelle 2 sind in Form der CSB-Werte (chemischer Sauerstoff-Bedarf) die bei einer konventionellen C-E-H-H-Sequenz und die bei der sauren O/P-Behandlung mit einer sich anschließenden H-H-Endbleiche anfallenden Abwasserbelastungen zu vergleichen.
Die Kappa-Zahl wurde durch die O/P-Stufe auf 8,3 erniedrigt. Die Werte für die Endweiße (R457) liegen mit 88,6 (a) und 89,2 (b) sehr dicht zusammen. Die Festigkeiten unterscheiden sich ebenfalls nur sehr wenig. Bei 30 SR werden nach a) 4,8 km Reißlänge und 820 mNm/m Weiterreißarbeit erhalten, nach b) 4,7 km Reißlänge und 830 mNm/m Weiterreißarbeit.The kappa number was reduced to 8.3 by the O / P stage. The values for the final whiteness (R457) are very close at 88.6 (a) and 89.2 (b). The strengths also differ very little. With 30 SR, 4.8 km tear length and 820 mNm / m tear strength are obtained, after b) 4.7 km tear length and 830 mNm / m tear strength.
Da der CSB-Wert ausschlaggebend für die Höhe der zu zahlenden Abwasserabgabe ist, erweist sich die Variante b als kostengünstiger. Sie ermöglicht die Verringerung der Abwasserbelastung durch Eindampfen und Verbrennen der in der sauren O/P-Stufe entstandenen Abwassermenge, in diesem Fall um 26,8 kg O2/t CSB.Since the COD value is decisive for the amount of the wastewater tax to be paid, variant b proves to be more cost-effective. It enables wastewater pollution to be reduced by evaporating and burning the amount of wastewater generated in the acidic O / P stage, in this case by 26.8 kg O 2 / t COD.
Die verbleibenden 43,1 kg O2/t CSB weisen einen BSB5-Wert (Biologischer Sauerstoff-Bedarf) von 32,3 kg O2/t auf, sind also zu 74,9 % abbaubar.The remaining 43.1 kg O 2 / t COD have a BS B 5 value (biological oxygen demand) of 32.3 kg O 2 / t, so they are 74.9% degradable.
Demgegenüber ergibt sich für Sequenz a mit 70,2 kg 02/t CSB ein BSB5-Wert von 21,2 kg O2/t, das entspricht einer Abbaurate von nur 30 %.In contrast, for sequence a with 70.2 kg 0 2 / t COD, there is a BOD 5 value of 21.2 kg O 2 / t, which corresponds to a degradation rate of only 30%.
An die O/P-Stufe können sich aber auch andere Bleichsequenzen wie z.B. CD-H-D, H-H-D bzw. P-D oder H-P-D, P-H, H-H anschließen.However, other bleaching sequences such as CD- HD, HHD or PD or HPD, PH, HH can also follow the O / P stage.
In Tabelle 3 sind die Ergebnisse einer weiteren Variante wiedergegeben.
Die Delignifizierung in der O/P-Stufe betrug nahezu 50 %, es wurde eine Kappa-Zahl von 10,5 ermittelt. Die Festigkeiten der mit beiden Sequenzen erzeugten Zellstoffe unterscheiden sich nur geringfügig; bei 30 SR wurden für a) und b) 6,2 bzw. 6,0 km Reißlänge sowie 1420 bzw. 1480 mNm/m Weiterreißarbeit ermittel.The delignification in the O / P stage was almost 50%, a kappa number of 10.5 was determined. The strengths of the pulps produced with both sequences differ only slightly; at 30 SR, 6.2 and 6.0 km tear length as well as 1420 and 1480 mNm / m tear tear were determined for a) and b).
Durch die Rückführung des Abwassers aus der sauren O/P-Stufe in den Chemikalienaufbereitungsprozeß des Aufschlusses läßt sich die Abwasserbelastung ausgedrückt als CSB um 48,6 % senken, während das aus der Bleichsequenz a resultierende Abwasser auf diese einfache Weise nicht reduziert werden kann.
Tabelle 4 belegt die Vorteile einer Kombination des erfindungsgemäßen Verfahrens mit der Sauerstoffdelignifizierung in Gegenwart von MgO, die Stand der Technik ist. Die Delignifizierung mit Sauerstoff in Gegenwart von Mg0 führt zu einem Ligninabbau auf ca. 60 % des Ausgangswerts. Durch die anschließende saure Behandlung mit Sauerstoff und Wasserstoffperoxid wird die Kappa-Zahl auf 8,2 entsprechend <40 % des Ausgangswertes gesenkt. Da sowohl das Abwasser der OMgO- als auch das der O/P-Stufe der Eindampfung zugeführt werden kann, ist eine Verminderung des CSB im Abwasser um über 60 % möglich.Table 4 shows the advantages of a combination of the method according to the invention with oxygen delignification in the presence of MgO, which is state of the art. Delignification with oxygen in the presence of Mg0 leads to a lignin breakdown to approx. 60% of the initial value. Subsequent acid treatment with oxygen and hydrogen peroxide reduces the kappa number to 8.2, corresponding to <40% of the initial value. Since both the wastewater of the O Mg O and the O / P stage of the evaporation can be fed, a reduction of the COD in the wastewater by over 60% is possible.
Eine weitere bevorzugte Ausführungsform besteht in der Kombination mit der Delignifizierung in Gegenwart von Magnesiumoxid, Wasserstoffperoxid und Sauerstoff im alkalischen Bereich. Das folgende Beispiel betrifft Delignifizierung und Bleiche eines Buchesulfit-Zellstoffs mit einer Kappa-Zahl von 16,3:Another preferred embodiment consists in the combination with the delignification in the presence of magnesium oxide, hydrogen peroxide and oxygen in the alkaline range. The following example concerns delignification and bleaching of a book sulfite pulp with a kappa number of 16.3:
- O/P in Gegenwart von MagnesiumoxidO / P in the presence of magnesium oxide
- Chemikalien: 1,4 % H202, 1 % MgO, 0,5 % O2 Chemicals: 1.4% H202, 1% M g O, 0.5% O 2
- Bedingungen: 14 % Stoffd., 98°C, 90 Min.Conditions: 14% substance, 98 ° C, 90 min.
Diese Behandlung vermindert die Kappa-Zahl um 6,5 Einheiten auf 9,8. Der Restperoxidgehalt beträgt 0,78 %. Durch Zugabe von weiterem Sauerstoff und überschüssiger Schwefelsäure wird ohne Zwischenwäsche eine saure O/P-Behandlung angeschlossen:This treatment reduces the kappa number by 6.5 units to 9.8. The residual peroxide content is 0.78%. By adding further oxygen and excess sulfuric acid, an acidic O / P treatment is connected without intermediate washing:
- O/P in Gegenwart von SäureO / P in the presence of acid
- Chemikalien: 0,5 % 02, 2 % H 2 S0 4 Chemicals: 0.5% 0 2 , 2% H 2 S0 4
- Bedingungen: 12 % Stoffdichte, 95°C, 60 Min.Conditions: 12% fabric density, 95 ° C, 60 min.
In dieser Stufe liegt der pH-Wert am Ende bei 1,8, der Restperoxidgehalt bei 0,12 % und die Kappa-Zahl bei 5,1. Durch eine intensive Wäsche nach diesen Stufen ist eine Abwasserbelastung von 52,4 kg 02/t CSB erfaßbar. Die Endbleiche des Zellstoffs ist mit zwei Hypochloritstufen möglich:
- Bedingungen: 10 % Stoffd., 50°C, 120 Min.
- Chemikalien: H1-Stufe, 1,5 % NaOCl, 0,15 % Amidoschwefelsäure H2-Stufe, 0,5 % NaOCl, 0,05 % Amidoschwefelsäure
- Conditions: 10% substance, 50 ° C, 120 min.
- Chemicals: H 1 level, 1.5% NaOCl, 0.15% amidosulfuric acid H2 level, 0.5% NaOCl, 0.05% amidosulfuric acid
Aus der Nachbleiche resultiert eine Belastung des Abwassers von 21,1 kg 02/t CSB. Der Endweißgehalt beträgt 90,8 % Remission (R457).Post-bleaching results in a wastewater load of 21.1 kg 0 2 / t COD. The final whiteness is 90.8% remission (R 457 ).
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT85108213T ATE48290T1 (en) | 1984-08-01 | 1985-07-03 | PROCESSES FOR DELIGNIFICATION AND BLEACHING OF PULP. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3428352 | 1984-08-01 | ||
| DE19843428352 DE3428352A1 (en) | 1984-08-01 | 1984-08-01 | METHOD FOR DELIGNIFICATION AND BLEACHING OF CELLULAS |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0171575A1 true EP0171575A1 (en) | 1986-02-19 |
| EP0171575B1 EP0171575B1 (en) | 1989-11-29 |
Family
ID=6242107
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP85108213A Expired EP0171575B1 (en) | 1984-08-01 | 1985-07-03 | Process for the delignification and bleaching of cellulose pulps |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4626319A (en) |
| EP (1) | EP0171575B1 (en) |
| AT (1) | ATE48290T1 (en) |
| DE (2) | DE3428352A1 (en) |
| FI (1) | FI852505L (en) |
| NO (1) | NO852472L (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0874082A1 (en) * | 1997-04-25 | 1998-10-28 | SOLVAY & Cie (Société Anonyme) | Continuous process for delignification and/or bleaching of virgin or recycled chemical pulp |
| DE19751173A1 (en) * | 1997-11-19 | 1999-05-27 | Voith Sulzer Papiertech Patent | Pulp bleaching method especially for recycling used paper materials |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2566015B1 (en) * | 1984-06-15 | 1986-08-29 | Centre Tech Ind Papier | PROCESS FOR BLEACHING MECHANICAL PASTE WITH HYDROGEN PEROXIDE |
| NO852330L (en) * | 1985-06-10 | 1986-12-11 | Papirind Forskningsinst | PROCEDURES FOR PEROXIDE BLACKING OF CELLULOSE-CONTAINING Masses. |
| AT392987B (en) * | 1989-06-08 | 1991-07-25 | Waagner Biro Ag | Process for adding hydrogen peroxide solution |
| DE3923728A1 (en) * | 1989-07-18 | 1991-01-24 | Degussa | METHOD FOR STABILIZING THE VISCOSITY OF CELLS |
| US5211809A (en) * | 1991-05-21 | 1993-05-18 | Air Products And Chemicals, Inc,. | Dye removal in oxygen color stripping of secondary fibers |
| US6231718B1 (en) | 1992-02-28 | 2001-05-15 | International Paper Company | Two phase ozone and oxygen pulp treatment |
| US5364465A (en) * | 1992-12-07 | 1994-11-15 | Archer Daniels Midland Company | Method of producing protein products for bright paper coating applications |
| US5387317A (en) * | 1993-01-28 | 1995-02-07 | The Mead Corporation | Oxygen/ozone/peracetic aicd delignification and bleaching of cellulosic pulps |
| FI944348A (en) * | 1994-09-19 | 1996-03-20 | Ahlstroem Oy | Procedure for bleaching of pulp |
| US6881299B2 (en) * | 2001-05-16 | 2005-04-19 | North American Paper Corporation | Refiner bleaching with magnesium oxide and hydrogen peroxide |
| US20050087315A1 (en) | 2003-10-28 | 2005-04-28 | Donovan Joseph R. | Low consistency oxygen delignification process |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2040763A1 (en) * | 1970-05-11 | 1971-11-18 | Kymin Oy Kymmene Ab | Two-stage bleaching of cellulose-containing materials |
| US3719552A (en) * | 1971-06-18 | 1973-03-06 | American Cyanamid Co | Bleaching of lignocellulosic materials with oxygen in the presence of a peroxide |
| WO1979000637A1 (en) * | 1978-02-17 | 1979-09-06 | Mo Och Domsjoe Ab | Bleaching lignocellulose material with bleaching agents containing peroxide |
| US4372812A (en) * | 1978-04-07 | 1983-02-08 | International Paper Company | Chlorine free process for bleaching lignocellulosic pulp |
| EP0087553A1 (en) * | 1982-02-27 | 1983-09-07 | Degussa Aktiengesellschaft | Process for producing half-bleached cellulose pulps |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE360128C (en) * | 1970-08-25 | 1983-08-02 | Mo Och Domsjoe Ab | SET TO BLAKE CELLULOSAMASSA WITH AN ACID-INHALING GAS IN THE PRESENT OF ALKALI |
| US4427490A (en) * | 1978-04-07 | 1984-01-24 | International Paper Company | Delignification and bleaching process for lignocellulosic pulp with peroxide in the presence of metal additives |
| US4410397A (en) * | 1978-04-07 | 1983-10-18 | International Paper Company | Delignification and bleaching process and solution for lignocellulosic pulp with peroxide in the presence of metal additives |
-
1984
- 1984-08-01 DE DE19843428352 patent/DE3428352A1/en not_active Withdrawn
-
1985
- 1985-06-19 NO NO852472A patent/NO852472L/en unknown
- 1985-06-25 FI FI852505A patent/FI852505L/en not_active Application Discontinuation
- 1985-07-03 DE DE8585108213T patent/DE3574486D1/en not_active Expired - Lifetime
- 1985-07-03 AT AT85108213T patent/ATE48290T1/en active
- 1985-07-03 EP EP85108213A patent/EP0171575B1/en not_active Expired
- 1985-07-22 US US06/757,242 patent/US4626319A/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2040763A1 (en) * | 1970-05-11 | 1971-11-18 | Kymin Oy Kymmene Ab | Two-stage bleaching of cellulose-containing materials |
| US3719552A (en) * | 1971-06-18 | 1973-03-06 | American Cyanamid Co | Bleaching of lignocellulosic materials with oxygen in the presence of a peroxide |
| WO1979000637A1 (en) * | 1978-02-17 | 1979-09-06 | Mo Och Domsjoe Ab | Bleaching lignocellulose material with bleaching agents containing peroxide |
| US4372812A (en) * | 1978-04-07 | 1983-02-08 | International Paper Company | Chlorine free process for bleaching lignocellulosic pulp |
| EP0087553A1 (en) * | 1982-02-27 | 1983-09-07 | Degussa Aktiengesellschaft | Process for producing half-bleached cellulose pulps |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0874082A1 (en) * | 1997-04-25 | 1998-10-28 | SOLVAY & Cie (Société Anonyme) | Continuous process for delignification and/or bleaching of virgin or recycled chemical pulp |
| BE1011129A4 (en) * | 1997-04-25 | 1999-05-04 | Solvay Interox | Delignification continuous process and / or money virgin pulp chemical or recycled. |
| DE19751173A1 (en) * | 1997-11-19 | 1999-05-27 | Voith Sulzer Papiertech Patent | Pulp bleaching method especially for recycling used paper materials |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0171575B1 (en) | 1989-11-29 |
| FI852505A0 (en) | 1985-06-25 |
| FI852505L (en) | 1986-02-02 |
| ATE48290T1 (en) | 1989-12-15 |
| NO852472L (en) | 1986-02-03 |
| DE3574486D1 (en) | 1990-01-04 |
| US4626319A (en) | 1986-12-02 |
| DE3428352A1 (en) | 1986-02-13 |
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