WO1997036039A1

WO1997036039A1 - A multicomponent system for changing, degrading or bleaching lignin, lignin-containing materials or similar substances and processes for its use

Info

Publication number: WO1997036039A1
Application number: PCT/EP1997/001545
Authority: WO
Inventors: Hans-Peter Call
Original assignee: Consortium für elektrochemische Industrie GmbH
Priority date: 1996-03-27
Filing date: 1997-03-26
Publication date: 1997-10-02
Also published as: AU2160397A; DE19612194A1

Abstract

This invention concerns a multicomponent system for changing, degrading or bleaching lignin, lignin-containing materials or similar substances and processes for its use, containing a) optionally, at least one oxidation catalyst and b) at least one suitable oxidant and c) at least one mediator, characterized by the fact that the mediator is selected from the oximes of general formula (I) or (II) and their salts, ethers, or esters, where the groups X are the same or different and are O, S, or NR1, where R1 means hydrogen, a hydroxy, formyl, carbamoyl or sulfono radical, an ester or salt of the sulfono radical, sulfamoyl, nitro, amino, phenyl, aryl-C¿1?-C5-alkyl, C1-C¿12-alkyl, C¿1?-C5-alkoxy, C1-C10-carbonyl, carbonyl-C1-C6-alkyl, a phospho, phosphono, or phosphonooxy radical, an ester or salt of the phosphonooxy radical where carbamoyl, sulfamoyl, amino and phenyl radicals can be unsubstituted or substituted one or several times with radical R?2¿ and the aryl-C¿1?-C5alkyl, C1-C12-alkyl, C1-C5-alkoxy, C1-C10-carbonyl, carbonyl-C1-C6-alkyl radicals can be saturated or unsaturated, branched or unbranched, and can be substituted one or several times with a radical R?2¿, where the radicals R2 are the same or different and means a hydroxy, formyl or carboxy radical, an ester or salt of the carboxy radical, a carbamoyl or sulfono radical, an ester or salt of the sulfono radical, a sulfamoyl, nitro, amino, phenyl, C¿1?-C5-alkyl or C1-C5-alcoxy radical and the radicals R?3-R4¿ are the same of different and signify a halogen or carboxy radical, an ester or salt of the carboxy radical, or they have the meanings given for R?1, R3 and R4¿ being optionally linked to a ring [-CR7R8]n, where n = 1, 2, 3, or 4, and R?5 and R6¿ have the meanings given for R?1, and R7 and R8¿ have the meanings given for R?3 and R4¿.

Description

Multi-component system for changing, breaking down or bleaching lignin, lignin-containing materials or similar substances as well as processes for its use

description

The present invention relates to a multi-component system for changing, breaking down or bleaching lignin, lignin-containing materials or similar substances, and methods for its use.

The sulfate and sulfite processes are the main processes used today for pulp production. With both methods, pulp is produced under cooking and under pressure. The sulfate process works with the addition of NaOH and Na ₂ S, while Ca (HS0 ₃ ) ₂ + S0 _{2 is used} in the sulfite process.

The main aim of all processes is to remove the lignin from the plant material, wood or annual plants used.

The lignin, which is the main constituent of the plant material (stem or stem) with cellulose and hemicellulose, must be removed, otherwise it will not be possible to produce non-yellowing and mechanically heavy-duty papers.

The wood-based production processes work with stone grinders (wood sanding) or with refiners (TMP), which defibrillate the wood by grinding after appropriate pretreatment (chemical, thermal or chemical-thermal).

These wood materials still contain a large part of the lignin. You will v. a. used for the production of newspapers, magazines, etc.

For some years now, the possibilities of using enzymes for lignin degradation have been researched. The mechanism of action Such lignolytic systems were only elucidated a few years ago when it was possible to obtain sufficient amounts of enzyme from the white rot fungus Phanero-chaete chrysosporium through suitable cultivation conditions and inductor additives. The previously unknown lignin peroxidases and manganese peroxidases were discovered. Since Phanerochaete chrysosporium is a very effective lignin degrader, attempts were made to isolate its enzymes and to use them in purified form for lignin degradation. However, this did not succeed because it turned out that the enzymes primarily lead to a repolymerization of the lignin and not to its degradation.

The same applies to other lignolytic enzyme species such as laccases, which oxidatively break down the lignin using oxygen instead of hydrogen peroxide. It was found that similar processes occur in all cases. This is because radicals are formed which react with one another again and thus lead to polymerization.

Today there are only processes that work with in vivo systems (mushroom systems). The main focus of optimization attempts is so-called biopulping and biobleaching.

Biopulping is the treatment of wood chips with living mushroom systems.

There are 2 types of application forms:

1. Pretreatment of wood chips before refining or grinding to save energy in the production of wood materials (e.g. TMP or wood pulp).

Another advantage is the mostly existing improvement in the mechanical properties of the fabric, a disadvantage the poorer final whiteness.

2. Pretreatment of wood chips (Softwood / Hardwood) before cellulose cooking (power process, sulfite process). The goal here is to reduce cooking chemicals, improve cooking capacity and "extended cooking".

Improved kappa reduction after cooking compared to cooking without pretreatment are also achieved as advantages.

Disadvantages of these procedures are clearly the long treatment times (several weeks) and especially the unresolved

Risk of contamination during treatment if you want to forego the uneconomical sterilization of the wood chips.

Biobleaching also works with in-vivo systems. The boiled pulp (Softwood / Hardwood) is inoculated with fungus before bleaching and treated for days to weeks. Only after this long treatment time does a significant decrease in kappa number and increase in whiteness become apparent, which makes the process uneconomical for implementation in the usual bleaching sequences.

Another application, which is usually carried out with immobilized fungal systems, is the treatment of pulp wastewater, in particular bleaching wastewater, for decolorization and reduction of the AOX (reduction of chlorinated compounds in the wastewater which cause chlorine or chlorine dioxide bleaching stages).

It is also known that hemicellulases, etc. Use xylanases, mannanases as "bleach boosters".

These enzymes are said to act primarily against the reprecipitated xylan, which partially covers the residual lignin after the cooking process, and by breaking it down increase the accessibility of the lignin to the bleaching chemicals used in the subsequent bleaching sequences (especially chlorine dioxide). The savings in bleaching chemicals demonstrated in the laboratory have been reflected in on a large scale has only been partially confirmed, so that this type of enzyme can at best be classified as a bleach additive.

In addition to the lignolytic enzymes, chelating substances (siderophores such as ammonium oxalate) and biosurfactants are assumed to be the cofactor.

The application PCT / EP87 / 00635 describes a system for removing lignin from lignin-cellulose-containing material under simultaneous bleaching, which works with lignolytic enzymes from white rot fungi with the addition of reducing and oxidizing agents and phenolic compounds as mediators.

In DE 4008893C2, in addition to the Red / Ox system, “mimic substances” which simulate the active center (prosthetic group) of lignolytic enzymes are added. In this way, a significant improvement in performance could be achieved.

In the application PCT / EP92 / 01086, a redox cascade is used as an additional improvement with the aid of phenolic or non-phenolic aromatics "matched" in the oxidation potential.

In all three processes, the limitation for large-scale use is the applicability at low material densities (up to a maximum of 4%) and in the last two applications the risk of "leaching out" of metals when using the chelate compounds, which are mainly in the case of downstream peroxide bleaching stages can lead to the destruction of the peroxide.

Methods are known from WO / 12619, WO 94/12620 and WO 94/12621 in which the activity of peroxidase is promoted by means of so-called enhancer substances.

The enhancer substances are characterized in WO 94/12619 on the basis of their half-life. According to WO 94/12620, enhancer substances are characterized by the formula A = NN = B, where A and B are each defined cyclic radicals.

According to WO 94/12620, enhancer substances are organic chemicals which contain at least two aromatic rings, at least one of which is substituted with respectively defined radicals.

All three applications relate to "dye transfer inhibition" and the use of the respective enhancer substances together with peroxidases as a detergent additive or detergent composition in the detergent sector. Although the description of the application refers to a usability for treating lignin, our own experiments with the substances specifically disclosed in the applications showed that they had no effect as mediators for increasing the bleaching effect of the peroxidases in the treatment of materials containing lignin!

WO 94/29510 describes a method for enzymatic delignification, in which enzymes are used together with mediators. Compounds with the structure NO, NOH or HRNOH are generally disclosed as mediators.

Of the mediators disclosed in WO 94/29510

1-Hydroxy-lH-benzotriazole (HBT) the best results in delignification. However, HBT has several disadvantages:

It is only available at high prices and not in sufficient quantities.

It reacts to lH-benzotriazole under delignification conditions. This compound is relatively poorly degradable and can represent a considerable environmental burden in larger quantities.

To some extent, it causes damage to enzymes. Its delignification rate is not too high.

The present invention relates to a multi-component system for changing, breaking down or bleaching lignin, lignin-containing materials or similar substances

a. optionally at least one oxidation catalyst and

b. at least one suitable oxidizing agent and

c. at least one mediator, characterized in that the mediator is selected from the group of oximes of the general formula I or II

Y

II

and their salts, ethers, or esters, where

X, is the same or different and is 0, S, or NR- ¹ - where

R ¹ hydrogen, hydroxy, formyl, carbamoyl, Sulfonorest, ester or salt of Sulfonorests, sulfamoyl, nitro, amino, phenyl, aryl-C ₁ - C ₅ ~ alkyl, C ₁ -C ₁₂ -Alkyl-, C ₁ -C ₅ -alkoxy-,

Means phospho, phosphono, phosphonooxy, ester or salt of the phosphonooxy, where carbamoyl, sulfamoyl, amino and phenyl unsubsti- ^r y tuiert or may be mono- or polysubstituted by a radical R, and aryl-C - ^ - Cg-alkyl, C- _| _-C ₁₂ -alkyl-, C _j -C ₅ -alkoxy-, C ^ C- _j ^ -carbony! -, carbonyl-C _j -Cg-alkyl radicals can be saturated or unsaturated, branched or unbranched and with one R ² can be substituted one or more times, wherein

R ^{2 is the} same or different and is hydroxyl, formyl, carboxy, ester or salt of carboxy, carbamoyl, sulfono ester or salt of sulfono, sulfamoyl, nitro, amino, phenyl, CL-Cg- Alkyl, C _j -Cς alkoxy radical means and

the radicals R ³ and R ^{4 are} identical or different and are halogen, carboxy, ester or salt of the carboxy radical, or have the meanings mentioned for R, or are linked to form a ring t-CR 7RRl _n with n equal to 2, 3 or 4 are and

R 5 and R6 have the meanings given for R1 and

R 7 and R8 are identical or different and represent halogen, carboxy radical, ester or salt of the carboxy radical, or have the meanings mentioned for R.

Particularly preferred mediators in the multicomponent system according to the invention are compounds of the general formula I in which X is 0 or S and the other radicals have the meanings given above. An example of such a compound is dimethyl 2-hydroxyiminomalonate.

Further preferred mediators are isonitroso derivatives of cyclic ureides of the general formula II. Examples of such compounds are 1-methylvioluric acid, 1, 3-dimethylvioluric acid, thiovioluric acid, alloxane-4, 5-dioxime,

Particularly preferred as mediator is alloxan-5-oxime hydrate (violuric acid) and / or its esters, ethers or salts. The multicomponent system according to the invention contains mediators which are less expensive than HBT.

In addition, an increase in the rate of delignification is achieved when using the mediators according to the invention.

The multicomponent system according to the invention preferably comprises at least one oxidation catalyst.

Enzymes are preferably used as oxidation catalysts in the multicomponent system according to the invention. In the sense of the invention, the term enzyme also encompasses enzymatically active proteins or peptides or prosthetic groups of enzymes.

Oxidoreductases of classes 1.1.1 to 1.97 according to the International Enzyme Nomenclature, Committee of the International Union of Biochemistry and Molecular Biology (Enzyme Nomenclature, Academic Press, Inc., 1992, pp. 24-154) can be used as the enzyme in the multicomponent system according to the invention. be used.

Enzymes of the classes mentioned below are preferably used:

Class 1.1 enzymes, which comprise all dehydrogenases which act on primary, secondary alcohols and semiacetals, and which accept NAD ⁺ or NADP ⁺ (subclass 1.1.1), cytochrome (1.1.2), oxygen (0 ₂ ) (1.1.3), disulfides (1.1.4), quinones (1.1.5) or the other acceptors (1.1.99).

From this class, the enzymes of class 1.1.5 with quinones as acceptors and the enzymes of class 1.1.3 with oxygen as acceptors are particularly preferred.

Cellobiose: quinone-1-oxidoreductase (1.1.5.1) is particularly preferred in this class. Enzymes of class 1.2 are also preferred. This class of enzymes (1.1.5.1) includes those enzymes which oxidize aldehydes to the corresponding acids or oxo groups. The acceptors can be NAD ⁺ , NADP ⁺ (1.2.1), cytochromes (1.2.2), oxygen (1.2.3), sulfides (1.2.4), iron-sulfur proteins (1.2.5) or other acceptors (1.2.99).

The enzymes of group (1.2.3) with oxygen as the acceptor are particularly preferred here.

Enzymes of class 1.3 are also preferred. This class includes enzymes that act on CH-CH groups of the donor.

The corresponding acceptors are NAD ⁺ , NADP ⁺ (1.3.1), Cyto¬ chrome (1.3.2), oxygen (1.3.3), quinones or related compounds (1.3.5), iron-sulfur proteins (1.3.7 ) or other acceptors (1.3.99).

Bilirubin oxidase (1.3.3.5) is particularly preferred.

The enzymes of class (1.3.3) with oxygen as the acceptor and (1.3.5) with quinones etc. as the acceptor are also particularly preferred here.

Also preferred are class 1.4 enzymes which act on CH-NH ₂ groups of the donor.

The corresponding acceptors are NAD ⁺ , NADP ⁺ (1.4.1), cytochrome (1.4.2), oxygen (1.4.3), disulfides (1.4.4), iron-sulfur proteins (1.4.7) or others Acceptors (1.4.99).

Enzymes of class 1.4.3 with oxygen as the acceptor are also particularly preferred here.

Also preferred are class 1.5 enzymes which act on CH-NH groups of the donor. The corresponding acceptors are NAD ⁺ , NADP ⁺ (1.5.1), oxygen (1.5.3), disulfide (1.5.4), quinones (1.5.5) or other acceptors (1.5.99).

Enzymes with oxygen (0 ₂ ) (1.5.3) and with quinones (1.5.5) as acceptors are also particularly preferred here.

Enzymes of class 1.6 which act on NADH or NADPH are also preferred.

The acceptors here are NADP ⁺ (1.6.1), heme proteins (1.6.2), disulfides (1.6.4), quinones (1.6.5), N0 ₂ groups (1.6.6), and a flavin (1.6.8 ) or some other acceptors (1.6.99).

Enzymes of class 1.6.5 with quinones as acceptors are particularly preferred here.

Also preferred are class 1.7 enzymes which act as donors on other N0 ₂ compounds and acceptors cytochrome (1.7.2), oxygen (0 ₂ ) (1.7.3), iron-sulfur proteins (1.7 .7) or others (1.7.99).

Class 1.7.3 with oxygen as the acceptor is particularly preferred here.

Also preferred are class 1.8 enzymes which act as donors on sulfur groups and NAD ⁺ , NADP ⁺ (1.8.1), cytochromes (1.8.2), oxygen (0 ₂ ) (1.8.3), disulphides as acceptors de (1.8.4), quinones (1.8.5), iron-sulfur proteins (1.8.7) or others (1.8.99).

Class 1.8.3 with oxygen is particularly preferred

and (1.8.5) with quinones as acceptors.

Also preferred are class 1.9 enzymes which act as donors on heme groups and have oxygen (0 ₂ ) (1.9.3), NO ₂ compounds (1.9.6) and others (1.9.99) as acceptors. Group 1.9.3 with oxygen (0 ₂ ) as acceptor (cytochrome oxidases) is particularly preferred here.

Also preferred are class 1.12 enzymes which act as a donor on hydrogen.

The acceptors are NAD ⁺ or NADP ⁺ (1.12.1) or others (1.12.99).

Enzymes of class 1.13 and 1.14 (oxigenases) are also preferred.

Preferred enzymes are also those of class 1.15 which act as acceptors on superoxide radicals.

Superoxide dismutase (1.15.1.1) is particularly preferred here.

Enzymes of class 1.16 are also preferred.

NAD ⁺ or NADP ⁺ (1.16.1) or oxygen (0 ₂ ) (1.16.3) act as acceptors.

Enzymes of class 1.16.3.1 (ferroxidase, e.g. ceruloplasmin) are particularly preferred here.

Further preferred enzymes are those belonging to the group

1.17 (effect on CH ₂ groups which are oxidized to -CHOH-),

1.18 (effect on reduced ferredoxin as donor), 1.19 (effect on reduced flavodoxin as donor) and 1.97 (other oxidoreductases).

Enzymes from group 1.11. Which act on a peroxide as acceptor are further particularly preferred. This only subclass (1.11.1) contains the peroxidases.

The cytochrome C peroxidases (1.11.1.5), catalase (1.11.1.6), the peroxidase (1.11.1.6), the iodide peroxidase (1.11.1.8), the glutathione peroxidase (1.11.1.9), the chloride peroxidase (1.11.1.10), the L-ascorbate peroxidase (1.11.1.11), the phospholipid hydroperoxide glutathione -Peroxidase (1.11.1.12), the manganese peroxidase (1.12.1.13), the diarylpropane peroxidase (ligninase, lignin peroxidase) (1.11.1.14).

Enzymes of class 1.10 which act on biphenols and related compounds are very particularly preferred. They catalyze the oxidation of biphenols and ascorbates. NAD ⁺ , NADP ⁺ (1.10.1), cytochrome (1.10.2), oxygen (1.10.3) or others (1.10.99) act as acceptors.

Of these in turn, class 1.10.3 enzymes with oxygen (0 ₂ ) as the acceptor are particularly preferred.

Of the enzymes in this class, the enzymes are catechol oxidase (tyrosinase) (1.10.3.1), L-ascorbate oxidase (1.10.3.3), o-aminophenol oxidase (1.10.3.4) and laccase (benzenediol: oxigen oxidoreductase) (1.10.3.2 ) is preferred, the laccases (benzol diol: oxigen oxidoreductase) (1.10.3.2) being particularly preferred.

The enzymes mentioned are commercially available or can be obtained by standard methods. Plants, animal cells, bacteria and fungi, for example, come into consideration as organisms for the production of the enzymes. In principle, both naturally occurring and genetically modified organisms can be enzyme producers. Parts of single-cell or multicellular organisms are also conceivable as enzyme producers, especially cell cultures.

For the particularly preferred enzymes, such as those from group 1.11.1, but above all 1.10.3, and in particular for the production of laccases, white rot fungi such as pleurus, phlebia and trametes are used, for example. The multi-component system according to the invention comprises at least one oxidizing agent. Examples of suitable oxidizing agents are air, oxygen, ozone, H ₂ O ₂ , organic peroxides, peracids such as peracetic acid, performic acid, persulfuric acid, persalpic acid, metachloroperoxibenzoic acid, perchloric acid, perborates, peracetates, persulfates, peroxides or acids ¬ substance species and their radicals such as OH ', OOH', singlet oxygen, superoxide (0 ₂ ' ^~ ), ozonide, dioxygenyl cation (0 ₂ ⁺ ), di¬ oxirane, dioxetane or fremy radicals are used.

Preferably oxidizing agents are used which can either be generated by the corresponding oxidoreductases e.g. Dioxiranes from laccases plus carbonyls or which can chemically regenerate the mediator or directly implement it.

The invention also relates to the use of substances which, according to the invention, are suitable as mediators for changing, breaking down or bleaching lignin, lignin-containing materials or similar substances.

The effectiveness of the multicomponent system when changing, breaking down or bleaching lignin, lignin-containing materials or similar substances is often further increased if, in addition to the constituents mentioned, Mg ⁺ ions are also present.

The Mg ions can be used, for example, as a salt, such as MgSO _* . The concentration is in the range of 0.1-2 mg / g of lignin-containing material, preferably 0.2-0.6 mg / g.

In some cases a further increase in the effectiveness of the multicomponent system according to the invention can be achieved in that the multicomponent system in addition to the Mg ⁺ ions also complexing agents such as, for example, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentamethylene - contains phosphonic acid (DTMPA), nitrilotriacetic acid (NTA), polyphosphoric acid (PPA) etc. The concentration is in Range of 0.2-5 mg / g of lignin-containing material, preferably 1-3 mg.

The multi-component system according to the invention is used in a process for treating lignin, for example, by mixing the respectively selected components a) to c) according to claim 1 simultaneously or in any order with an aqueous suspension of the lignin-containing material.

A process using the multicomponent system according to the invention is preferred in the presence of oxygen or air at atmospheric pressure up to 10 bar and in a pH range from 2 to 11, at a temperature of 20 to 95 ° C., preferably 40-95 ° C, and a consistency of 0.5 to 40%.

An unusual and surprising finding for the use of enzymes in pulp bleaching is that when the multicomponent system according to the invention is used, an increase in the consistency enables a significant increase in the kappa reduction.

For economic reasons, a process according to the invention is preferably carried out at consistencies of 8 to 35%, particularly preferably 9 to 15%.

Surprisingly, it was also found that an acid wash (pH 2 to 6, preferably 4 to 5) or Q stage (pH 2 to 6, preferably 4 to 5) before the enzyme mediator stage led to a considerable degree in some pulps Kappa reduction compared to treatment without this special pretreatment leads. In the Q stage, the substances customary for this purpose (such as EDTA, DTPA) are used as chelating agents. They are preferably used in concentrations of 0.1% / t to 1% / t, particularly preferably 0.1% / t to 0.5% / t. In the process according to the invention, preferably 0.01 to 10,000 IU enzyme per g lignin-containing material are used. It is particularly preferred to use 0.1 to 100, particularly preferably 1 to 40, IU of enzyme per g of lignin-containing material (1 U corresponds to the conversion of 1 μmol of 2,2'-azino-bis (3-ethyl-benzothiazoline) -6-sulfonic acid diammonium salt) (ABTS) / min / ml enzyme).

In the process according to the invention, preferably 0.01 mg to 100 mg of oxidizing agent per g of lignin-containing material is used. 0.01 to 50 mg of oxidizing agent per g of lignin-containing material are particularly preferably used.

In the method according to the invention, 0.5 to 80 mg of mediator per g of lignin-containing material is preferably used. 0.5 to 40 mg of mediator per g of lignin-containing material are particularly preferably used.

At the same time, reducing agents can be added which, together with the oxidizing agents present, serve to set a certain redox potential.

Sodium bisulfite, sodium dithionite, ascorbic acid, thio compounds, mercapto compounds or glutathione etc. can be used as reducing agents.

In the case of laccase, for example, the reaction proceeds with air or oxygen supply or oxygen or air pressure, in the case of the peroxidases (e.g. lignin peroxidases, manganese peroxidases) with hydrogen peroxide. In this case, for example, the oxygen can also be generated in situ by hydrogen peroxide + catalase and hydrogen peroxide by glucose + glucose oxidase or other systems.

In addition, radical formers or radical scavengers (trapping, for example, OH "or OOH" radicals) can be added to the system. These can improve the interaction within the Red / Ox and radical mediators. Other metal salts can also be added to the reaction solution.

These are important in conjunction with chelating agents as radical formers or red / ox centers. The salts form cations in the reaction solution. Such ions include Fe, Fe ^{3+ /} Mn ²⁺ , Mn ³⁺ , Mn ⁴⁺ , Cu ²⁺ , Ca ²⁺ , Ti ³⁺ , Cer ⁴⁺ , Al ³⁺ .

The chelates present in the solution can also serve as mimic substances for the enzymes, for example for the laccases (copper complexes) or for the lignin or manganese peroxidases (haem grain complexes). Mimic substances are substances that simulate the prosthetic groups of (here) oxidoreductases and e.g. Can catalyze oxidation reactions.

NaOCl can also be added to the reaction mixture. In combination with hydrogen peroxide, this compound can form singlet oxygen.

Finally, it is also possible to work with detergents. Non-ionic, anionic, cationic and amphoteric surfactants are suitable as such. The detergents can improve the penetration of the enzymes and mediators into the fiber.

It may also be beneficial for the reaction to add polysaccharides and / or proteins. Glucans, mannans, dextrans, levans, pectins, alginates or plant gums and / or own polysaccharides formed by the fungi or produced in the mixed culture with yeasts and in particular gelatin and albumin as proteins are to be mentioned here in particular as polysaccharides. These substances mainly serve as protective colloids for the enzymes.

Other proteins that can be added are proteases such as pepsin, bromelin, papain, etc. These can include serve to achieve better access to lignin by breaking down the extensin C present in the wood, a protein rich in hydroxyproline.

Amino acids, simple sugars, oligomer sugars, PEG types of the most varied molecular weights, polyethylene oxides, polyethyleneimines and polydimethylsiloxanes can be used as further protective colloids.

The method according to the invention can be used not only in the delignification (bleaching) of sulfate, sulfite, organosol, etc. Cellulose and wood pulp are used, but also in the production of cellulose or wood pulp (refiner / wood pulp) in general, for example from wood or annual plants. For this purpose, defibrillation should be ensured by the usual cooking processes and / or mechanical processes or pressure (i.e. very gentle treatment up to kappa numbers in the range of> 50 kappa or> 10% lignin content).

In the bleaching of cellulose as well as in the production of cellulose, the treatment can be repeated several times, either after washing and extraction of the treated material with NaOH or without these intermediate steps. This leads to significantly lower kappa values and considerable increases in whiteness. Likewise, a 0 ₂ stage can be used before the enzyme / mediator treatment or, as already mentioned, an acid wash or Q stage (chelate stage) can be carried out.

The invention is explained in more detail below with the aid of examples: Example 1: Enzymatic bleaching with violuric acid and Softwood sulfate pulp

5 g dry cellulose (Softwood 0 ₂ delignified), consistency 30% (approx. 17 g wet) are added to the following solutions:

A) 20 ml of tap water are mixed with 65 mg of violuric acid monohydrate while stirring, the pH with 0.5 mol / 1 H ₂ S0 ₄ solution. adjusted so that pH 4.5 results after addition of the pulp and the enzyme.

B) 5 ml of tap water are mixed with the amount of Laccase from Trame- tes versicolor that an activity of 35 U (1 U = conversion of 1 μmol ABTS / min / ml enzyme) results per g of pulp. Solutions A and B are combined and made up to 33 ml.

After adding the pulp, mix with a dough kneader for 2 min.

Then the substance is placed in a reaction bomb preheated to 45 ° C and incubated under 1 - 10 bar oxygen pressure for 10 to 40 minutes.

The fabric is then washed over a nylon sieve (30 μm) and extracted for 1 hour at 60 ° C., 2% fabric density and 8% NaOH per g of cellulose. After washing the fabric again, the kappa number is determined.

Depending on the incubation period, the following delignification rates are achieved:

Response time kappa lignin degradation

[min] after extraction [%]

0 * 10.40 0.00

10, 8, 00, 23, 10

20, 00 7.40 28, 80

30.00 7.00 32.70

40, 00 7.00 32, 70

Result * at 0 min (kappa before extraction) Example 2: Enzymatic bleaching with violuric acid and Softwood sulfate pulp

A) 20 ml of tap water are mixed with 130 mg of violuric acid monohydrate while stirring, the pH value with 0.5 mol / 1 H ₂ S0 ₄ solution. adjusted so that pH 4.5 results after addition of the pulp and the enzyme.

B) 5 ml of tap water are mixed with the amount of Laccase from Trameses versicolor that an activity of 35 U (1 U = conversion of 1 μmol ABTS / min / ml enzyme) results per g of pulp. Solutions A and B are combined and made up to 33 ml.

After adding the pulp, mix with a dough kneader for 2 min. The substance is then placed in a reaction bomb preheated to 45 ° C. and incubated under 1-10 bar oxygen pressure for 1-4 hours.

Duration of kappa lignin degradation

[h] after extraction [%]

0 * 10.40 0.00

4 4.90 52, 90

Result * at 0 min kappa before extraction

After a reac- time of 4 hours found 89%.

Comparative Example 1: Enzymatic bleaching with

1-hydroxy-1-H-benzotriazole and softwood sulfate pulp

A) 20 ml of tap water are mixed with 25 mg of 1-hydroxy-1H-benzotriazole with stirring, the pH with 0.5 mol / 1 H ₂ S0 ₄ solution. adjusted so that pH 4.5 results after addition of the pulp and the enzyme.

B) 5 ml of tap water are mixed with the amount of Laccase from Trameses versicolor that an activity of 35 U (1 U = conversion of 1 μmol ABTS / min / ml enzyme) results per g of pulp.

Solutions A and B are combined and made up to 33 ml.

After adding the pulp, mix with a dough kneader for 2 min. The substance is then placed in a reaction bomb preheated to 45 ° C. and incubated under 1-10 bar oxygen pressure for 10 to 40 minutes.

The fabric is then washed over a nylon sieve (30 μm) and extracted for 1 hour at 60 ° C, 2% fabric density and 8% NaOH per g of pulp.

After washing the fabric again, the kappa number is determined.

Response time kappa lignin degradation

[min] after extraction [%]

0 * 10.40 0.00

10, 00, 9.70, 6.70

20.00 9.30 10, 60

30, 00 8, 90 14.40

40.00 8.50 18.30

Result * at 0 min (kappa before extraction)

Comparative Example 2: Enzymatic bleaching with

1-hydroxy-1-H-benzotriazole and softwood sulfate pulp

5 g dry cellulose (Softwood 0 ₂ delignified), consistency

30% (approx. 17 g moist) are added to the following solutions:

A) 20 ml tap water with 50 mg

1-Hydroxy-1-H-benzotriazole added with stirring, the pH with 0.5 mol / 1 H ₂ S0 ₄ solution. adjusted so that pH 4.5 results after addition of the pulp and the enzyme.

Solutions A and B are combined and made up to 33 ml.

After adding the pulp, mix with a dough kneader for 2 min.

Then the substance is placed in a reaction bomb preheated to 45 ° C and under 1 - 10 bar oxygen pressure for 1 ■

Incubated for 4 hours.

The fabric is then washed over a nylon sieve (30 μm) and extracted for 1 hour at 60 ° C., 2% fabric density and 8% NaOH per g of cellulose. After washing the fabric again, the kappa number is determined. Depending on the incubation period, the following delignification rates are achieved:

Response time kappa lignin degradation

[h] after extraction [%]

0 * 10.40 0.00

4 5.60 46.20

Result * at 0 min kappa before extraction

15% of the enzyme activity used was recovered after a reaction time of 4 hours.

Claims

claims

1. Containing a multi-component system for changing, breaking down or bleaching lignin, lignin-containing materials or similar substances

a. optionally at least one oxidation catalyst and

b. at least one suitable oxidizing agent and

ΪI

and their salts, ethers, or esters, where

X, is the same or different and is 0, S, or NR ¹ where

R ^{1 is} hydrogen, hydroxyl, formyl, carbamoyl, sulfono, ester or salt of sulfono, sulfamoyl, nitro, amino, phenyl, aryl-C ₁ -C ₅ -alkyl-, C ^ C ^ -Alky! - _/ C ₁ -C ₅ -alkoxy-, C ₁ -C ₁₀ -carbonyl-, carbonyl-C- _{j ^} -Cg-alkyl-, phospho-, phosphono-, phosphonooxy radical, ester or salt of the phosphonooxy radical, where carbamoyl, sulfamoyl, amino and phenyl radicals can be unsubstituted or substituted one or more times with a radical R ² and the aryl-C ₁ -C ₅ -alkyl-, C ₁ -C ₁₂ -alkyl-, C ₁ -C ₅ alkoxy, C ₁ -C ₁₀ carbonyl, carbonyl-C - ^ - Cg-alkyl radicals can be saturated or unsaturated, branched or unbranched and can be substituted one or more times with a radical R ² in which

R ^{2 is the} same or different and hydroxyl, formyl, carboxy radical, ester or salt of the carboxy radical, carbamoyl, sulfono ester or salt of the sulfono radical, sulfamoyl, nitro, amino, phenyl, C- -Cg -Alkyl-, CL-Cς alkoxy radical means and

the radicals R -R ^{4 are} identical or different and are halogen, carboxy, ester or salt of the carboxy, or have the meanings mentioned for R, or to form a ring

[-CR 7'R8 ⁰ ] ,, are linked to n equal to 2, 3 or 4 and

R S and R6 have the meanings given for R1 and

R 7 and R8 are the same or different and represent halogen, carboxy radical, ester or salt of the carboxy radical, or those for

R have meanings mentioned.

2. Multi-component system according to claim 1, characterized gekenn¬ characterized in that it comprises at least one oxidation catalyst.

3. Multi-component system according to claim 1 or 2, characterized in that enzyme is used as the oxidation catalyst.

4. Multi-component system according to one of claims 1 to 3, characterized in that laccase is used as the enzyme.

5. Multi-component system according to one of claims 1 to 4, characterized in that air, oxygen, ozone, H ₂ 0 ₂ , organic peroxides, peracids as the oxidizing agent Peracetic acid, performic acid, persulfuric acid, persalpeteric acid, metachlorperoxibenzoic acid, perchloric acid, perborates, peracetates, persulfates, peroxides or oxygen species and their radicals such as OH ", 00H ^* , singlet oxygen, superoxide (0 ₂ ' ^_ ), ozonide, dioxygenyl cation ₂ ⁺ ), Dioxirane, Dioxetane or Fremy radicals are used.

6. Multi-component system according to one of claims 1 to 5, characterized in that compounds of the general formula I in which X is O or S and the other radicals have the meanings mentioned above are used as mediators.

7. Multi-component system according to one of claims 1 to 6, characterized in that isonitroso derivatives of cyclic ureides of the general formula II are used as mediators.

8. Multi-component system according to one of claims 1 to 7, characterized in that as mediator alloxan-5-oxime hydrate (violuric acid) or its esters, ethers or salts are used.

9. A method for treating lignin, characterized in that the components a) to c) selected in each case according to

Claim 1 mixes simultaneously or in any order with an aqueous suspension of the lignin-containing material.

10. Use of mediators according to claim 1 for changing, breaking down or bleaching lignin, lignin-containing materials or similar substances.