EP0447673B1 - Process of enzymatic bleaching of pulp - Google Patents

Process of enzymatic bleaching of pulp Download PDF

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Publication number
EP0447673B1
EP0447673B1 EP90125380A EP90125380A EP0447673B1 EP 0447673 B1 EP0447673 B1 EP 0447673B1 EP 90125380 A EP90125380 A EP 90125380A EP 90125380 A EP90125380 A EP 90125380A EP 0447673 B1 EP0447673 B1 EP 0447673B1
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EP
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Prior art keywords
process according
aqueous solution
added
solution containing
bleaching
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German (de)
French (fr)
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EP0447673A1 (en
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Hans-Peter Dr. Call
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LIGNOZYM GESELLSCHAFT ZUR HERSTELLUNG UND ZUM VERT
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LIGNOZYM GESELLSCHAFT ZUR HERSTELLUNG und ZUM VERTRIEB VON ENZYMEN mbH
Lignozym GmbH
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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
    • D21C9/1084—Bleaching ; Apparatus therefor with reducing compounds
    • 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
    • D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
    • D21C5/005—Treatment of cellulose-containing material with microorganisms or enzymes
    • 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
    • D21C9/1084—Bleaching ; Apparatus therefor with reducing compounds
    • D21C9/1089—Bleaching ; Apparatus therefor with reducing compounds with dithionites
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/10—Bleaching ; Apparatus therefor
    • D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/10—Bleaching ; Apparatus therefor
    • D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
    • D21C9/153—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications with ozone
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/10—Bleaching ; Apparatus therefor
    • D21C9/16—Bleaching ; Apparatus therefor with per compounds
    • D21C9/163—Bleaching ; Apparatus therefor with per compounds with peroxides

Definitions

  • the present invention relates to a method for the enzymatic bleaching of cellulose.
  • DE-C-31 10 117 discloses a process for the production of cellulose from wood or other plant fiber materials, in which the lignocellulose is broken down with the help of white rot fungi.
  • the processes using microorganisms have considerable disadvantages. So far it has not been possible to achieve degradation and detachment of the lignin from its accompanying polymers (cellulose) without simultaneous growth of the microorganisms and without loss of cellulose. The simultaneous growth of the fungus leads to very long breakdown times, which can take up to several weeks.
  • Chlorine bleach is associated with major environmental problems.
  • the kappa number ie the lignin content
  • the pulp is thus brightened.
  • WO-A-88/03190 a method for removing and / or converting lignin or its degradation products from cellulose-containing material is known.
  • a redox potential between 200 and 500 mV is set by adding oxidizing agents and / or reducing agents and / or salts and / or phenolic compounds to an acidic, lignin-containing solution.
  • the lignin-degrading reaction is then started by adding enzymes.
  • a disadvantage of this process is that a satisfactory bleaching effect cannot yet be achieved by adding the specified substances.
  • the object of the present invention is to provide a process for the enzymatic bleaching of cellulose in which a) a redox potential in the range between 200 and 500 mV is set with the simultaneous addition of oxidizing and reducing agents and addition of salts to an aqueous solution, and b) a bleaching reaction is started by adding lignolytic enzymes.
  • the object is achieved in that the aqueous cellulose-containing solution as a salt copper (II) sulfate or a mixture of copper (II) sulfate with Mn (II) sulfate. Mn (II) acetate. Fe (II) sulfate. Ti (III) chloride. Ce (III) nitrate and / or Ce (IV) ammonium nitrate and complexing agents are added and the reaction is maintained with constant stirring for 15 minutes to 2 hours.
  • the redox potential is preferably between 250 and 450 mV.
  • it can be determined by means of a redox electrode and by means of a controller and an actuator during the entire reaction time by adding oxidizing and reducing agents. Salts and phenolic compounds are kept constant.
  • Hydrogen peroxide is preferably used as the oxidizing agent. Oxygen and ozone are used. Ascorbic acid, dithionite and sodium bisulfite are suitable as reducing agents.
  • Copper (II) sulfate is added to the cellulose-containing aqueous solution as the salt.
  • Ce (III) nitrate and Ce (IV) ammonium nitrate can be used. Saize also come with the elements zinc. Antimony and lead are considered.
  • phenolic compounds can be added to the aqueous cellulose-containing solution. Veratryl alcohols have proven particularly useful as such.
  • fatty acids e.g. Oleic acids
  • heme compounds e.g. Hemoglobin
  • bleaching reagents e.g. Sodium perborate
  • post-bleaching can be carried out using common bleaching agents, such as sodium hypochlorite, O2, chlorine dioxide, ozone, H2O2 and sodium ionite.
  • EDTA ethylenediaminetetraacetic acid
  • DTPA diethylenetriaminepentraacetic acid
  • aqueous cellulose-containing solution Sodium hypochlorite, sodium perborate, detergents, surfactants and polysaccharides such as glucans and xanthans are suitable as such.
  • Lignolytic enzymes are preferably used as enzymes in the method according to the invention. These include phenol oxidases, laccases and peroxidases. The effectiveness of the method can be increased by using pectinase and / or hemicellulases. Particularly suitable lignolytic enzymes are those which are obtained from the white rot fungus Phanerochaete chrysosporium. The use of such enzymes is already known from US-A-4,692,413, 4,690,895 and 4,687,741. However, according to these patents, enzymes obtained from special mutants from Phanerochaete chrysosporium are used for bleaching. According to the invention, however, this is not necessary.
  • the pH is usually between 2 and 5. A pH of 3 is particularly preferred.
  • the temperature is 20 to 60 ° C., preferably 40 ° C. If the conditions are observed, the substances mentioned are added Redox potential set from 200 to 500 mV. This is determined by the ratio of the various substances added in the reaction vessel. By appropriate measurement and control of the addition of the oxidizing and reducing agents, the salts and possibly the phenolic compounds, it can be maintained throughout the reaction time.
  • the bleaching process is started by simultaneous dosing of H2O2 and sodium bisulfite solution.
  • the redox potential of approx. 400 mV is maintained. After the process is started, it continues for 2 hours.
  • the process is controlled and regulated by means of a redox electrode and a pump control.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Chemical & Material Sciences (AREA)
  • Biochemistry (AREA)
  • Microbiology (AREA)
  • Paper (AREA)
  • Preparation Of Compounds By Using Micro-Organisms (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)
  • Breeding Of Plants And Reproduction By Means Of Culturing (AREA)
  • Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
  • Nitrogen Condensed Heterocyclic Rings (AREA)
  • Detergent Compositions (AREA)
  • Medicinal Preparation (AREA)
  • Cosmetics (AREA)

Abstract

The present invention concerns a process for the enzymatic bleaching of celluloses in which a) a redox potential in the range between 200 and 500 mV is set with the simultaneous dosed addition of oxidation and reducing agents and the addition of salts and complex formers to provide an aqueous cellulose-containing solution; b) a bleaching reaction is initiated by the addition of lignolytic enzymes; and c) the reaction is maintained for 15 minutes to 12 hours under continuous agitation.

Description

Die vorliegende Erfindung betrifft ein Verfahren zum enzymatischen Bleichen von Zellstoffen.The present invention relates to a method for the enzymatic bleaching of cellulose.

Die bisher bekannten biologischen Verfahren zur Zellstoffherstellung arbeiten mit Mikroorganismen, insbesondere mit Pilzen. So ist aus der DE-C-31 10 117 ein Verfahren zur Gewinnung von Zellulose aus Holz oder anderen Pflanzenfasernmaterialien bekannt, bei dem die Lignozellulose mit Hilfe von Weißfäulepilzen abgebaut wird. Die mit Mikroorganismen arbeitenden Verfahren haben jedoch erhebliche Nachteile. So ist es bislang nicht möglich, ohne gleichzeitiges Wachstum der Mikroorganismen und ohne Verlust an Cellulose einen Abbau und ein Loslösen des Lignins von seinen Begleitpolymeren (Zellulose) zu erreichen. Durch das gleichzeitige Wachstum des Pilzes treten sehr lange Abbauzeiten auf, die bis zu mehreren Wochen dauern können.The previously known biological processes for pulp production work with microorganisms, in particular with fungi. DE-C-31 10 117 discloses a process for the production of cellulose from wood or other plant fiber materials, in which the lignocellulose is broken down with the help of white rot fungi. However, the processes using microorganisms have considerable disadvantages. So far it has not been possible to achieve degradation and detachment of the lignin from its accompanying polymers (cellulose) without simultaneous growth of the microorganisms and without loss of cellulose. The simultaneous growth of the fungus leads to very long breakdown times, which can take up to several weeks.

In den letzten Jahren sind wegen der dargestellten Schwierigkeiten des Einsatzes von Mikroorganismen die Verwendungsmöglichkeiten für isolierte Enzymsysteme untersucht worden. Insbesondere wurden die Enzyme des Weißfäulepilzes Phanerochaete chrysosporium erforscht und in vielen Einzelheiten aufgeklärt. So ist aus ''Biotechnology in the Pulp and Paper Industry, 3. International Conference, Stockholm 1986'' bekannt, daß beim Abbau von Lignin das Gleichgewicht der Reaktion auf der Polymerisationsseite liegt, d.h. zellfreie Systeme bauen kein Lignin ab bzw. polymerisieren es.In recent years, the potential uses for isolated enzyme systems have been investigated because of the difficulties presented with the use of microorganisms. In particular, the enzymes of the white rot fungus Phanerochaete chrysosporium were researched and elucidated in many details. It is known from '' Biotechnology in the Pulp and Paper Industry, 3rd International Conference, Stockholm 1986 '' that when lignin is broken down, the equilibrium of the reaction lies on the polymerization side, i.e. cell-free systems do not break down or polymerize lignin.

In der Literatur ist auch seit der Entdeckung der lignolytischen Enzyme beim Weißfäulepilz Phanerochaete chrysosporium eine Reihe von enzymatischen Verfahren zum Bleichen von Zellstoff mit lebenden Pilzsystemen und auch von zellfreien Systemen bekannt geworden. Ebenso wurde eine Reihe von Versuchen unternommen, mit Hämsystemen zu bleichen. Alle diese Systeme benötigen Reaktionszeiten von mehr als 12 Stunden. D.h. allen diesen Systemen sind ein großer Zeitaufwand und hohe Kosten zu eigen. Letzteres trifft insbesondere für die reinen Hämsysteme zu.Since the discovery of the lignolytic enzymes in the white rot fungus Phanerochaete chrysosporium, a number of enzymatic processes for bleaching pulp with living fungal systems and also cell-free systems have become known in the literature. A number of attempts have also been made to bleach with heme systems. All of these systems require response times of more than 12 hours. I.e. all of these systems are time consuming and costly. The latter applies in particular to the pure hamming systems.

Heutzutage wird eine Bleiche noch rein chemisch in mehreren Stufen unter Zusatz von Chlor durchgeführt. Die Chlorbleiche ist aber mit großen Umweltproblemen verbunden. Bei den Bleichverfahren wird im allgemeinen durch Entfernung der beim Kochprozeß zur Ligninentfernung entstandenen chromophoren Restlignin-Kondensationsprodukte die Kappazahl, d.h. der Ligningehalt erniedrigt und so der Zellstoff aufgehellt.Nowadays, bleaching is still done chemically in several stages with the addition of chlorine. Chlorine bleach is associated with major environmental problems. In the bleaching process, the kappa number, ie the lignin content, is generally reduced by removing the chromophoric residual lignin condensation products formed in the cooking process for lignin removal, and the pulp is thus brightened.

Aus der EP-A-0345715 ist ein Verfahren bekannt, bei dem lignolytische Enzyme zusammen mit Peroxiden zum Abbau von lignocellulosehaltigem Material eingesetzt werden. Die Ergebnisse dieses Verfahrens sind jedoch noch nicht zufriedenstellend hinsichtlich Bleichwirkung und Bleichzeit.A method is known from EP-A-0345715 in which lignolytic enzymes are used together with peroxides to break down material containing lignocellulose. However, the results of this process are not yet satisfactory in terms of bleaching action and bleaching time.

Aus J.P. Casey "Pulp and Paper; Chemistry and Chemical Technology", dritte Ausgabe, Band I, 1980, John Wiley & Sons, New York, Seiten 651, 652 ist ein rein chemisches Verfahren zum Bleichen bekannt. Aber auch dieses Verfahren ist nicht zufriedenstellend was die Zeit angeht. Auch hinsichtlich der Umwelteinflüsse ist man heute eher bestrebt, biologische oder enzymatische Verfahren einzusetzen, auch wenn die Bleichwirkung und Bleichzeit nicht so gut sind wie in der genannten Literaturstelle.From J.P. Casey "Pulp and Paper; Chemistry and Chemical Technology", Third Edition, Volume I, 1980, John Wiley & Sons, New York, pages 651, 652 discloses a purely chemical bleaching process. But this method is also unsatisfactory in terms of time. With regard to environmental influences, efforts are now being made to use biological or enzymatic processes, even if the bleaching effect and bleaching time are not as good as in the cited literature reference.

Aus der WO-A-88/03190 ist ein Verfahren zur Entfernung und/oder Umwandlung von Lignin oder dessen Abbauprodukten aus zellulosehaltigem Material bekannt. Hierbei wird durch Zusatz von Oxidationsmitteln und/oder Reduktionsmitteln und/oder Salzen und/oder phenolischen Verbindungen zu einer sauren, ligninhaltigen Lösung ein Redoxpotential zwischen 200 und 500 mV eingestellt. Durch Zugabe von Enzymen wird die ligninabbauende Reaktion sodann gestartet. Nachteilig bei diesem Verfahren ist jedoch, daß sich durch die Zugabe der angegebenen Substanzen noch keine zufriedenstellende Bleichwirkung erreichen läßt.From WO-A-88/03190 a method for removing and / or converting lignin or its degradation products from cellulose-containing material is known. Here, a redox potential between 200 and 500 mV is set by adding oxidizing agents and / or reducing agents and / or salts and / or phenolic compounds to an acidic, lignin-containing solution. The lignin-degrading reaction is then started by adding enzymes. A disadvantage of this process, however, is that a satisfactory bleaching effect cannot yet be achieved by adding the specified substances.

Die vorliegende Erfindung hat sich die Aufgabe gestellt, ein Verfahren zum enzymatischen Bleichen von Zellstoffen, bei welchen a) unter gleichzeitiger Zudosierung von Oxidations- und Reduktionsmitteln und Zusatz von Salzen zu einer wässrigen Lösung ein Redoxpotential im Bereich zwischen 200 und 500 mV eingestellt und b) durch Zugabe von lignolytischen Enzymen eine Bleichreaktion gestartet wird zur Verfügung zu stellen.The object of the present invention is to provide a process for the enzymatic bleaching of cellulose in which a) a redox potential in the range between 200 and 500 mV is set with the simultaneous addition of oxidizing and reducing agents and addition of salts to an aqueous solution, and b) a bleaching reaction is started by adding lignolytic enzymes.

Die Aufgabe wird dadurch gelöst, daß der wässrigen zellstoffhaltigen Lösung als Salz Kupfer (II) sulfat oder ein Gemisch von Kupfer (II) sulfat mit Mn (II) sulfat. Mn (II) acetat. Fe (II) sulfat. Ti (III) chlorid. Ce (III) nitrat und/oder Ce (IV) amoniumnitrat sowie Komplexbildner zugesetzt werden und die Reaktion unter ständigem Rühren über 15 Minuten bis 2 Stunden aufrechterhalten wird.The object is achieved in that the aqueous cellulose-containing solution as a salt copper (II) sulfate or a mixture of copper (II) sulfate with Mn (II) sulfate. Mn (II) acetate. Fe (II) sulfate. Ti (III) chloride. Ce (III) nitrate and / or Ce (IV) ammonium nitrate and complexing agents are added and the reaction is maintained with constant stirring for 15 minutes to 2 hours.

Das Redoxpotential liegt vorzugsweise zwischen 250 und 450 mV. Es kann bei dem erfindungsgemäßen Verfahren mittels einer Redoxelektrode ermittelt und mittels eines Reglers und eines Stellgliedes während der gesamten Reaktionszeit durch die Zugabe von Oxidations- und Reduktionsmitteln. Salzen und phenolischen Verbindungen konstant gehalten werden.The redox potential is preferably between 250 and 450 mV. In the method according to the invention, it can be determined by means of a redox electrode and by means of a controller and an actuator during the entire reaction time by adding oxidizing and reducing agents. Salts and phenolic compounds are kept constant.

Als Oxidationsmittel werden vorzugsweise Wasserstoffperoxid. Sauerstoff und Ozon eingesetzt. Als Reduktionsmittel kommen Ascorbinsäure, Dithionit und Natrium-Bisulfit in Frage.Hydrogen peroxide is preferably used as the oxidizing agent. Oxygen and ozone are used. Ascorbic acid, dithionite and sodium bisulfite are suitable as reducing agents.

Als Salz wird der zellstoffhaltigen wässrigen Lösung Kupfer(II) sulfat zugesetzt. Zusätzlich können als Salze Mn(II)sulfat. Mn (III)Acetat. Fe(II)sulfat. Ti(III)chlorid. Ce(III)nitrat und Ce(IV)amoniumnitrat eingesetzt werden. Ebenso kommen Saize mit den Elementen Zink. Antimon und Blei in Betracht.Copper (II) sulfate is added to the cellulose-containing aqueous solution as the salt. In addition, salts Mn (II) sulfate. Mn (III) acetate. Fe (II) sulfate. Ti (III) chloride. Ce (III) nitrate and Ce (IV) ammonium nitrate can be used. Saize also come with the elements zinc. Antimony and lead are considered.

Ggf. können der wässrigen zellstoffhaltigen Lösung phenolische Verbindungen zugesetzt werden. Als solche haben sich inbesondere Veratrylalkohole bewährt.Possibly. phenolic compounds can be added to the aqueous cellulose-containing solution. Veratryl alcohols have proven particularly useful as such.

Ferner können der wässrigen zellstoffhaltigen Lösung Fettsäuren z.B. Ölsäuren, Hämverbindungen z.B. Hämoglobin und Bleichreagenzien z.B. Natriumperborat zugesetzt werden. Darüber hinaus kann eine Nachbleiche mit gängigen Bleichmitteln, wie Natriumhypochlorit, O₂, Chlordioxid, Ozon, H₂O₂ und Natriumtionit durchgeführt werden.Furthermore, fatty acids e.g. Oleic acids, heme compounds e.g. Hemoglobin and bleaching reagents e.g. Sodium perborate can be added. In addition, post-bleaching can be carried out using common bleaching agents, such as sodium hypochlorite, O₂, chlorine dioxide, ozone, H₂O₂ and sodium ionite.

Außerdem sei darauf hingewiesen, daß der Zusatz von Komplexbildnern für den Erfolg des erfindungsgemäßen Verfahrens sehr wichtig ist. Als solche werden vorzugsweise Ethylendiamintetraessigsäure (EDTA) oder Diethylentriaminpentraessigsäure (DTPA) eingesetzt. Sobald das erforderliche Redoxpotential eingestellt ist, beginnt relativ schnell der Bleichprozeß, der innerhalb weniger Minuten schon beendet sein kann, allerdings mit kaum erniedrigter Kappazahl, welche in Abhängigkeit vom Zellstoffgehalt nach einigen Stunden bis zu 90 % vermindert werden kann.It should also be pointed out that the addition of complexing agents is very important for the success of the process according to the invention. As such, preference is given to using ethylenediaminetetraacetic acid (EDTA) or diethylenetriaminepentraacetic acid (DTPA). As soon as the required redox potential has been set, the bleaching process begins relatively quickly, which can be completed within a few minutes, but with a hardly reduced kappa number, which can be reduced by up to 90% after a few hours, depending on the cellulose content.

Zusätzlich zu den genannten Stoffen können der wässrigen zellstoffhaltigen Lösung weitere Substanzen zugesetzt werden. Als solche kommen Natriumhypochlorit, Natriumperborat, Detergenzien, Tenside und Polysaccharide, wie Glukane und Xanthane in Betracht.In addition to the substances mentioned, further substances can be added to the aqueous cellulose-containing solution. Sodium hypochlorite, sodium perborate, detergents, surfactants and polysaccharides such as glucans and xanthans are suitable as such.

Als Enzyme werden bei dem erfindungsgemäßen Verfahren vorzugsweise lignolytische Enzyme eingesetzt. Hierzu zählen unter anderem Phenoloxidasen, Laccasen und Peroxidasen. Die Wirksamkeit des Verfahrens kann durch Einsatz von Pektinase und/oder Hemicellulasen noch erhöht werden. Besonders geeignete lignolytische Enzyme sind solche, die aus dem Weißfäulepilz Phanerochaete chrysosporium gewonnen werden. Der Einsatz solcher Enzyme ist bereits aus den US-A-4 692 413, 4 690 895 und 4 687 741 bekannt. Allerdings werden nach diesen Patentschriften aus speziellen Mutanten aus Phanerochaete chrysosporium gewonnene Enzyme zum Bleichen eingesetzt. Erfindungsgemäß ist dies hingegen nicht erforderlich. Vielmehr können bei Einhaltung der dargestellten Bedingungen alle heute bekannten lignolytischen Enzyme eingesetzt werden. Der Hauptunterschied ist in der Funktion der zudosierten reduzierenden oder oxidierenden Stoffe und Mediatoren, welche als Radikalfänger fungieren, zu sehen. Diese Stoffe verhindern nämlich eine Repolymerisierung des Lignins und ermöglichen dadurch erst einen Ligninabbau in der beschriebenen Weise und Menge innerhalb der erwähnten kurzen Zeitspanne.Lignolytic enzymes are preferably used as enzymes in the method according to the invention. These include phenol oxidases, laccases and peroxidases. The effectiveness of the method can be increased by using pectinase and / or hemicellulases. Particularly suitable lignolytic enzymes are those which are obtained from the white rot fungus Phanerochaete chrysosporium. The use of such enzymes is already known from US-A-4,692,413, 4,690,895 and 4,687,741. However, according to these patents, enzymes obtained from special mutants from Phanerochaete chrysosporium are used for bleaching. According to the invention, however, this is not necessary. Rather, all lignolytic enzymes known today can be used if the conditions shown are observed. The main difference is the function of the added reducing or oxidizing substances and mediators, which act as radical scavengers. This is because these substances prevent repolymerization of the lignin and thus enable lignin degradation in the manner and quantity described within the short period of time mentioned.

Bei dem erfindungsgemäßen Verfahren liegt der pH-Wert gewöhnlich zwischen 2 und 5. Besonders bevorzugt wird ein pH-Wert von 3. Die Temperatur beträgt 20 bis 60° C, vorzugsweise 40° C. Bei Einhaltung der Bedingungen wird unter Zusatz der genannten Stoffe ein Redoxpotential von 200 bis 500 mV eingestellt. Dabei wird dies durch das Verhältnis der verschiedenen zugesetzten Stoffe im Reaktionsgefäß bestimmt. Durch die entsprechende Messung und Regelung der Zugabe der Oxidations- und Reduktionsmittel, der Salze und ggf. der phenolischen Verbindungen kann es während der gesamten Reaktionszeit aufrechterhalten werden.In the process according to the invention, the pH is usually between 2 and 5. A pH of 3 is particularly preferred. The temperature is 20 to 60 ° C., preferably 40 ° C. If the conditions are observed, the substances mentioned are added Redox potential set from 200 to 500 mV. This is determined by the ratio of the various substances added in the reaction vessel. By appropriate measurement and control of the addition of the oxidizing and reducing agents, the salts and possibly the phenolic compounds, it can be maintained throughout the reaction time.

Mit dem geschilderten Bleichverfahren ist es erstmals gelungen, innerhalb sehr kurzer Zeit (15 Minuten - 2 Stunden) bei physiologischen Temperaturen (40° C) ohne Druck und mit geringsten Zugaben an chemischen Stoffen kostengünstig und vor allem umweltschonend Zellstoffe zu bleichen. Ein weiterer Vorteil des erfindungsgemäßen Verfahrens ist die Möglichkeit der kontinuierlichen Verfahrensführung.With the bleaching process described, it was possible for the first time to bleach cellulose inexpensively and above all in an environmentally friendly manner within a very short time (15 minutes - 2 hours) at physiological temperatures (40 ° C) without pressure and with the smallest addition of chemical substances. Another advantage of the process according to the invention is the possibility of continuous process control.

Das erfindungsgemäße Verfahren wird anhand der folgenden Beispiele näher erläutert:
50 g atro Zellstoff (Sulfatzellstoff) werden in einem Rührgefäß bei 1 % Stoffdichte bei ca. 500 rpm und 40 °C gerührt. Der pH-Wert wird mit 1 n HCL auf pH 3 eingestellt. Es werden 0,1 - 1,5 % H₂O₂ auf atro Stoff bezogen, ca. 2 x 10⁻⁵ % - 2 x 10⁻³ % Veratrylalkohol (VA) und 0,1 % EDTA oder DTPA, 0,001 - 0,01 % Kupfer(II)sulfat bezogen auf atro Stoff zugesetzt. Nach Zugabe von 500 - 5000 IU lignolytischer Enzyme (1 IU = Umsatz von 1 nmol VA/min. in Veratrylaldehyd) wird der Bleichprozeß durch gleichzeitige Dosierung von H₂O₂ und Natrium-Bisulfit-Lösung in Gang gesetzt. Hierbei wird das Redoxpotential von ca. 400 mV aufrechterhalten. Nachdem der Prozeß eingeleitet ist, wird dieser für 2 Stunden fortgesetzt. Die Steuerung und Regelung des Prozesses wird mittels einer Redoxelektrode und einer Pumpensteuerung durchgeführt.The process according to the invention is explained in more detail using the following examples:
50 g of dry cellulose (sulfate pulp) are stirred in a stirred vessel at 1% consistency at approx. 500 rpm and 40 ° C. The pH is adjusted to pH 3 with 1N HCL. There are 0.1 - 1.5% H₂O₂ related to atro material, approx. 2 x 10 2% - 2 x 10⁻³% veratryl alcohol (VA) and 0.1% EDTA or DTPA, 0.001 - 0.01% Copper (II) sulfate based on dry substance added. After adding 500 - 5000 IU of lignolytic enzymes (1 IU = conversion of 1 nmol VA / min. In veratrylaldehyde) the bleaching process is started by simultaneous dosing of H₂O₂ and sodium bisulfite solution. The redox potential of approx. 400 mV is maintained. After the process is started, it continues for 2 hours. The process is controlled and regulated by means of a redox electrode and a pump control.

Claims (23)

  1. A process for enzymatical bleaching of pulps,
    wherein
    a) a redox potential in the range between 200 and 500 mV is adjusted while metered addition of oxidants and reductives and the addition of salts to an aqueous solution takes place simultaneously,
    b) a bleaching reaction is started by adding lignolytical enzymes,
    characterised in that
    as salts copper(II)sulphate or a mixture of copper(II)sulphate with Mn(II)sulphate, Mn(II)acetate, Fe(II)sulphate, Ti(III)chloride, Ce(III)nitrate and/or Ce(IV)ammonium nitrate are added together with complexing agents to the aqueous solution containing pulp, and the reaction is maintained for a period of 15 minutes up to 2 hours during which time it is constantly stirred.
  2. A process according to claim 1,
    characterised in that ethylene diamine tetraacetic acid (EDTA) or diethylene triamine pentaacetic acid (DTPA) is used as complexing agent.
  3. A process according to claim 1 or 2,
    characterised in that polysaccharides are added to the aqueous solution containing pulp.
  4. A process according to claim 3,
    characterised in that the polysaccharides are glucanes and/or xanthane.
  5. A process according to any of the claims 1 to 4,
    characterised in that detergents are added to the aqueous solution containing pulp.
  6. A process according to any of the claims 1 to 5,
    characterised in that surface-active agents are added to the aqueous solution containing pulp.
  7. A process according to any of the claims 1 to 6,
    characterised in that fatty acids are added to the aqueous solution containing pulp.
  8. A process according to claim 7,
    characterised in that oleic acids are used as fatty acids.
  9. A process according to any of the claims 1 to 8,
    characterised in that haeme compounds are added to the aqueous solution containing pulp.
  10. A process according to claim 9,
    characterised in that haemoglobin is used as haeme compound.
  11. A process according to any of the claims 1 to 10,
    characterised in that lignine peroxidases and laccases are used as lignolytical enzymes.
  12. A process according to any of the claims 1 to 11,
    characterised in that phenolic compounds are additionally added to the aqueous solution containing pulp for the purpose of adjusting the redox potential.
  13. A process according to claim 12,
    characterised in that veratryl alcohol is used as the phenolic compound.
  14. A process according to any of the claims 1 to 13,
    characterised in that pectinases and/or hemicellulases are used in addition to the lignolytical enzymes.
  15. A process according to any of the claims 1 to 14,
    characterised in that the pH value is between 2 and 5.
  16. A process according to any of the claims 1 to 15,
    characterised in that the pH value is 3.
  17. A process according to any of the claims 1 to 16,
    characterised in that the temperature is between 20 and 60° C.
  18. A process according to any of the claims 1 to 17,
    characterised in that the temperature is 40°C.
  19. A process according to any of the claims 1 to 18,
    characterised in that sodium hypochlorite is added to the reacting solution.
  20. A process according to any of the claims 1 to 19,
    characterised in that bleaching reagents are additionally added to the aqueous solution containing pulp.
  21. A process according to claim 20,
    characterised in that sodium perborate is used as bleaching reagent.
  22. A process according to any of the claims 1 to 21,
    characterised in that an extraction is carried out by means of Na0H and/or H₂SO₄ after the reaction is completed.
  23. A process according to any of the claims 1 to 22,
    characterised in that sodium hypochlorite, chlorine, chlorine dioxide, O₂, ozone, H₂0₂ and sodium dithionite are used for the after-bleach.
EP90125380A 1990-03-20 1990-12-22 Process of enzymatic bleaching of pulp Expired - Lifetime EP0447673B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4008893 1990-03-20
DE4008893A DE4008893A1 (en) 1990-03-20 1990-03-20 METHOD FOR ENZYMATIC BLEACHING OF CELLULAS

Publications (2)

Publication Number Publication Date
EP0447673A1 EP0447673A1 (en) 1991-09-25
EP0447673B1 true EP0447673B1 (en) 1995-03-08

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Country Status (13)

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EP (1) EP0447673B1 (en)
JP (1) JPH05505857A (en)
AT (1) ATE119593T1 (en)
AU (1) AU641494B2 (en)
BR (1) BR9106411A (en)
CA (1) CA2078345A1 (en)
DE (2) DE4008893A1 (en)
DK (1) DK0447673T3 (en)
ES (1) ES2072965T3 (en)
FI (1) FI924169A (en)
HU (1) HUT64119A (en)
NO (1) NO180388C (en)
WO (1) WO1991014823A1 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4137761A1 (en) * 1991-05-17 1992-11-19 Call Hans Peter METHOD FOR DELIGNIFYING LIGNOCELLULOSE-CONTAINING MATERIAL, BLEACHING AND TREATING WASTEWATER BY LACCASE WITH EXTENDED EFFECTIVENESS
FI914780A0 (en) * 1991-10-10 1991-10-10 Valtion Teknillinen FOERFARANDE FOER ENTSYMATISK BEHANDLING AV LIGNOCELLULOSAHALTIGA MATERIAL, I SYNNERHET CELLULOSAMASSOR.
CA2115881C (en) * 1993-02-25 2000-05-23 Michael G. Paice Non-chlorine bleaching of kraft pulp
CA2165426C (en) * 1993-06-16 2007-11-27 Hans-Peter Call Multi-component bleaching system
BE1007272A3 (en) * 1993-07-15 1995-05-09 Solvay Method of a pulp bleach.
EP0652321B1 (en) * 1993-11-04 1998-01-21 Morton International, Inc. Chemical pulp bleaching
DE19820947B4 (en) * 1997-05-12 2005-12-01 Call, Krimhild Enzymatic bleaching system with novel enzyme action enhancing compounds for altering, degrading or bleaching lignin, lignin containing materials, or altering or degrading coal, and methods using the bleaching system
JP2001515136A (en) * 1997-08-14 2001-09-18 隆司 渡邊 Chemical method for lignin depolymerization
CA2328125C (en) 1998-04-16 2005-09-27 Pulp And Paper Research Institute Of Canada Oxidase process for pulp and dye oxidation

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3110117C2 (en) * 1981-03-16 1983-09-29 Adolf 5340 St. Gilgen Basler Production of cellulose from wood or other lignocellulose-containing plants through microbial degradation of the lignocellulose
US4692413A (en) * 1985-07-15 1987-09-08 Repligen Corporation Use of rLDM™ 1-6 and other ligninolytic enzymes for the decolorization of E1 effluent
US4687741A (en) * 1985-07-15 1987-08-18 Repligen Corporation Novel enzymes which catalyze the degradation and modification of lignin
US4690895A (en) * 1985-07-15 1987-09-01 Repligen Corporation Use of rLDM™ 1-6 and other ligninolytic enzymes in the bleaching of kraft pulp
DE3636208A1 (en) * 1986-10-24 1988-05-05 Call Hans Peter METHOD FOR DELIGNIFYING AND WHICH BLEACHING LIGNICELLULOSE-CONTAINING OR LIGNINAL MATERIAL OR LIGNIN BY ENZYMATIC TREATMENT
ZA894239B (en) * 1988-06-08 1990-03-28 Int Paper Co Enzymatic delignification of lignocellulosic material

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
J.P. Casey "Pulp and Paper; Chemistry and Chemical Technology" dritte Auflage, Band I, 1980, John Wiley & Sons, New York, Seiten 651, 652. *

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HUT64119A (en) 1993-11-29
NO180388C (en) 1997-04-09
FI924169A0 (en) 1992-09-17
BR9106411A (en) 1993-05-04
CA2078345A1 (en) 1991-09-21
ATE119593T1 (en) 1995-03-15
AU641494B2 (en) 1993-09-23
HU9202982D0 (en) 1993-01-28
ES2072965T3 (en) 1995-08-01
DE4008893C2 (en) 1992-09-03
FI924169A (en) 1992-09-17
DE4008893A1 (en) 1991-09-26
NO923601D0 (en) 1992-09-16
DE59008655D1 (en) 1995-04-13
NO180388B (en) 1996-12-30
AU7543291A (en) 1991-10-21
JPH05505857A (en) 1993-08-26
WO1991014823A1 (en) 1991-10-03
DK0447673T3 (en) 1995-07-24
NO923601L (en) 1992-09-16
EP0447673A1 (en) 1991-09-25

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