Method of delignifying and bleaching pulp with activated hydrogen peroxide

FIELD: chemistry.

SUBSTANCE: invention relates to a method of delignifying and bleaching pulp, which includes at least a step of bringing the pulp into contact with hydrogen peroxide and a molybdenum-based complex of formula (I): where R denotes an unsaturated C5-C6 cycloalkyl group or an unsaturated C5-C6 heterocycloalkyl group, substituted or unsubstituted, and Ar denotes an aryl group optionally having one or more substitutes in the aromatic rings, which are one or more linear or branched C1-C4-alkyl groups, -halogen, -NO2, -OH, -COOH.

EFFECT: reduced cellulose decomposition and consumption of chemical compounds.

14 cl, 1 tbl

 

The scope to which the invention relates.

The present invention relates to a method for the delignification and bleaching of paper pulp activated by hydrogen peroxide.

The level of technology

In the production of paper pulp as raw material use wood. The wood contains, in particular, cellulose fiber white and coloured lignin.

Therefore, the paper production involves mainly the delignification (removal of lignin and/or bleaching of paper pulp. To preserve the mechanical properties required for the production and use of paper, it is desirable that the cellulose was destroyed as little as possible during the process.

For example, it is known the use of chlorine-containing compounds (chlorine, chlorine dioxide, hypochlorite) for delignification and bleaching of pulp. Due to the cost of these compounds and the formation of chlorinated derivatives in wastewater, their use should be reduced.

It is also known the use of oxygen, ozone or hydrogen peroxide as agents of delignification and bleaching. However, the use of these agents is not really satisfactory. These agents have the property of bleaching and/or specificity, less than that of chlorine-containing products. In particular, these agents can cause the destruction of the cellulose and higher soda is the content of lignin. The high content of lignin limits the degree of mass bleaching and leads to premature yellowing and aging of paper. In addition, the depolymerization of cellulose weakens the fibers and, therefore, the strength of paper.

Activation of hydrogen peroxide high temperature also leads to a significant destruction of the cellulose. Also have been proposed technologies for catalytic activation of hydrogen peroxide.

In particular, it is known the use of various transition metals and/or complexes on the basis of transition metals for the activation of hydrogen peroxide.

For example, in WO 03/080925 described method of bleaching and delignification of paper pulp, based on the use of hydrogen peroxide, activated complex copper-phenanthroline.

In patent CA 1129161 described method of bleaching and delignification of paper pulp using the acid hydrogen peroxide-activated ion of metal selected from the group consisting of tungsten, molybdenum, chromium, osmium, selenium.

In article Catalysis and activation of oxygen and peroxide delignification of chemical pulps: a review, M.Suchy and D.S.Argyropoulos, April 2002, volume 1, no.2 Tappi Journal provides an overview of various studies, the aim of which is to improve the delignification of paper pulp with oxygen and hydrogen peroxide. In this document, in particular, we are talking about the use of complexes deferoxamine is in an acidic environment.

In article Activation of alkaline peroxide delignification using a vanadium peroxo complex, M. Suchy and D.S.Argyropoulos, June 2000, vol. 83, no 6 Tappi Journal talking about the use of a complex of peroxo-vanadium in an alkaline environment.

However, it is still difficult to find a satisfactory compromise between the reduction of lignin content and integrity of the cellulose in the paper pulp.

In addition, the bleaching of paper pulp with hydrogen peroxide is usually carried out at alkaline pH and requires, therefore, an activator of hydrogen peroxide, acting in an alkaline environment. Thus, as indicated above, in most ways from the prior art is used as an activator for hydrogen peroxide in an acidic environment.

Thus, there is a need to develop ways of delignification and bleaching of paper pulp, improved compared with the methods of the prior art, providing more efficient delignification and/or reduce the destruction of the cellulose and/or a reduction in the consumption of chemical compounds (chlorine, in particular). There is also a need in the way of delignification and bleaching of paper pulp, remaining effective at alkaline pH.

Brief description of the invention

Primarily, the invention relates to a method for the delignification and bleaching of paper pulp, comprising at least a stage of bringing into contact paper pulp with peroxy the om hydrogen and complex on the basis of molybdenum formula (I):

(I)

where

R is unsaturated C5-C6-cycloalkyl group or unsaturated C5-C6-geterotsyklicescoe group, substituted or unsubstituted, and

Ar denotes an aryl group optionally having one or more substituents on aromatic () the ring(s)representing one or more linear or branched C1-C4-alkyl groups, -halogen, -NO2, -OH, -COOH.

Preferably R is a C5-cycloalkenyl or C6-aromatic group, preferably cyclopentadienyls group.

Preferably Ar denotes a phenyl group.

By "unsaturated C5-C6-cycloalkyl" in the present invention realize unsaturated, substituted or unsubstituted cyclic hydrocarbon radical, which may contain 5 or 6 carbon atoms. For example, you can call cyclopentadienyl.

Under "substituted" group understand the atom or group of atoms, in particular hydrogen, substituted C1-C6-alkyl group, hydroxyl or halogen.

By "unsaturated heterocyclization" in the present invention unsaturated understand cycloalkenyl radical such as defined above, and the specified cycloalkyl system contains at least one heteroatom, in particular selected from the group consisting of sulfur, oxygen, nitrogen, phosphorus and preference is sustained fashion nitrogen. As unsaturated geterotsiklicheskie can be called, for example, pyridine, unsubstituted or substituted one of the groups listed above.

By "aryl" in the present invention understand aromatic system containing at least one ring satisfying the rule of aromaticity of hukkala, i.e. contains 4n+2 π-electrons delocalized in the ring (where n is a natural integer). Specified aryl may contain (poly)ring of 6-24 carbon atoms, for example 6 to 12 carbon atoms, in particular 6 to 10 carbon atoms, more specifically, a ring of 6 carbon atoms. Specified aryl may contain one heteroatom in the ring. Specified aryl optionally substituted, for example, one of the above groups. For example, the aryl group can be phenyl, cyclobenzarine, nitrobenzyloxy, trilinos group.

Unexpectedly, the complex on the basis of molybdenum used in the method according to the invention have proven particularly effective in comparison with activators of hydrogen peroxide from the prior art and even in an alkaline environment. Without regard to any theory, the inventors attribute this special performance by acetylneuraminic connection, which provides stabilization of the catalyst in its various States of oxidation, Mo(V) and Mo (VI).

Unless otherwise indicated, hereinafter in the description, all percentages indicated the Ana in mass values.

In accordance with the embodiment system based on molybdenum is oncoproliferative-molybdenum (VI), formula (II):

(II)

According to one of embodiments of pH paper pulp to regulate 7-12, preferably from 7 to 11, at the stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of molybdenum, preferably by adding sodium hydroxide. Maintaining an alkaline pH helps to create optimal conditions for the action of hydrogen peroxide. Complex of molybdenum according to the invention is preferable, because it remains effective even if it is used in an alkaline environment.

According to one of embodiments a stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of molybdenum is carried out at a temperature from 10°C to 120°C, preferably from 20°to 100°C., more specifically from 30°C to 80°C.

According to one of embodiments a stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of molybdenum lasts from 1 minute to 4 hours, preferably from 30 minutes to 3 hours.

According to one of embodiments during the stage of bringing into contact paper pulp with hydrogen peroxide and to the complex on the basis of molybdenum consistency paper pulp is from 1% to 40% of the mass. dry paper pulp, preferably from 5% to 30% of the mass. dry paper pulp, in relation to the total dry weight of pulp.

Under the "consistency" understand the concentration of mass, such as defined in ISO 4119 from June 1996: is the ratio of the mass of the anhydrous substance, which can be filtered from the sample suspended mass, the mass of the unfiltered sample, and the experiment is carried out in accordance with the international standard. The concentration of mass is expressed in this case in mass percent.

Under "dry" paper weight, thus, understand the weight suspended anhydrous substance sample mass, such as defined in the above standard ISO 4119 measured after filtration and drying in accordance with this standard.

According to one embodiments, the initial content of hydrogen peroxide at the stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of molybdenum is less than or equal to 10% of the mass. dry paper pulp, preferably less than or equal to 4% of the mass. dry paper pulp and, more specifically, is from 0.1% to 2% of the mass. dry paper pulp.

According to one of embodiments a number of complex on the basis of molybdenum at the stage of bringing into contact paper pulp with hydrogen peroxide is about is about 0.001% to 1% of the mass. dry paper pulp, preferably from 0.01% to 0.2% of the mass. dry paper pulp, preferably from 0.01% to 0.1% of the mass. dry paper pulp.

In accordance with a variant implementation of the method includes:

obtaining an aqueous solution of the complex on the basis of molybdenum interaction of the precursor complex on the basis of molybdenum and aqueous hydrogen peroxide, followed by addition of an aqueous solution of the complex on the basis of molybdenum in the pulp; or

adding a paper weight of the precursor complex on the basis of molybdenum in solid form or in aqueous solution.

The specified predecessor complex on the basis of molybdenum preferably represents a complex formula CpMo(CO)3(C≡CPh), where Cf denotes cyclopentadienyls group, and Ph denotes a phenyl group. Preferably we are talking about tricarbocyanines-molybdenum (VI).

The second variant implementation of this method mainly lies in the fact that the complex on the basis of molybdenum is formed in situ in the paper pulp interaction with those already present by hydrogen peroxide. Thus, the addition of hydrogen peroxide is not necessary.

The invention also relates to a method of obtaining and processing of paper pulp, including:

the first stage of penetration is required before timber, preferably in the presence of g is of droxia sodium and sodium sulfide to obtain paper pulp;

optional preliminary stage of delignification and bleaching of paper pulp with oxygen;

the delignification and bleaching of paper pulp by the method according to the invention described above;

optional stage delignification and bleaching of paper pulp by alkaline extraction and/or treatment with ozone, and/or processing peracetic acid, and/or bringing into contact with hydrogen peroxide, and/or chlorine-containing compound, such as chlorine dioxide.

Additional stage delignification and bleaching can be performed both before and after one or more stages of delignification and bleaching, pre-and related method according to the invention. The selection of the additional stage is done depending on the target application.

The invention also relates to a method for producing paper, including the receipt and processing of paper pulp by the above method with subsequent cutting into sheets and dried.

Of course, paper pulp, obtained by the method according to the invention may not contain any traces of the complex on the basis of molybdenum and/or its predecessor, referred to above, in particular, due to the operations of washing, breeding and other methods aimed at removing impurities.

The present invention provides for elimination of the deficiencies of the prior art. More spiral is but we propose a method of delignification and bleaching of paper pulp, providing more efficient delignification and/or reduce the destruction of the cellulose, and/or reducing the consumption of chemical compounds. It is also proposed a method of delignification and bleaching of paper pulp, remaining effective at alkaline pH compared with the methods of the prior art.

This is achieved through the use of hydrogen peroxide, activated complex on the basis of molybdenum formula (I) or, more specifically of the formula (II).

In accordance with some private options for implementing the invention also has one or preferably more of the preferred characteristics listed below.

Compared with using only the hydrogen peroxide method according to the invention allows to obtain a better delignification and causes the same or less than the destruction of the cellulose fibers.

Compared with the use of peroxide of hydrogen, catalytically activated in accordance with the prior art (for example, phenanthroline in complex with copper or ammonium molybdate), the method according to the invention allows less to destroy the cellulose fibers and to achieve more efficient delignification (or, alternatively, consume a smaller amount of hydrogen peroxide).

Compared with activators of peroxide in Dorada from the prior art, which are only active in an acidic environment, the complex on the basis of molybdenum formula (I) or (II) remains effective in an alkaline environment and, thus, is the most suitable for delignification and bleaching of paper pulp.

- Complex of molybdenum formula (II) provides a particularly effective anyway.

Description of embodiments of the invention

The invention is described in more detail, but without limitation, in the following description.

Getting a paper pulp according to the invention includes a step of penetration is required before timber, preferably in the presence of sodium hydroxide and sodium sulfide to obtain paper pulp (chemical pulp).

Stage penetration is required before it can be completed within 8-12 hours at a temperature of from 80°C to 200°C, for example at 170°C.

Thus obtained pulp is subjected to delignification and bleaching or only with the use of hydrogen peroxide, activated complex on the basis of molybdenum according to the invention, or by one or more additional processing before or after processing, in which use complex on the basis of molybdenum.

Additional stages of treatment can be a treatment with hydrogen peroxide (active or neaktivirovannye complex on the basis of molybdenum), treatment with oxygen, the processing of oz is. the processing of chlorine containing compounds, in particular chlorine dioxide, or processing any other bleaching agent (peracetic acid ...). These processing stages may also be any conventional stage known methods of bleaching (extraction, leaching, chelation ...).

Application processing with hydrogen peroxide, activated complex on the basis of molybdenum, allows, anyway, to shorten the duration of these additional processing or consumption of reagents (for example, chlorine dioxide and/or peracetic decollate) at equivalent or superior outcome for the delignification and bleaching compared with the prior art.

It should be noted that the machining stage with hydrogen peroxide, activated complex on the basis of molybdenum, can be performed once or several times (for example, twice).

Between two consecutive stages of processing using complex on the basis of molybdenum and/or additional stages of the paper pulp may be subjected to pressing and washing. It is dried on the press for mass after completion of the combined stages of processing, or sent to the paper machine.

Complex of molybdenum, used according to the invention corresponds to the formula (I). Complex of molybdenum, is laudisa preferred according to the invention, corresponds to the formula (II). We are talking about complex oncoproliferative-molybdenum (VI).

Complex oncoproliferative-molybdenum (VI) was described in “Selective oxidation of aromatic primary alcohols to aldehydes using molybdenum acetylide oxoperoxo complex as catalyst” Ankush V. Biradar, Mohan K.Dongare, Shubhangi B.Umbarkar, Tetrahedron Letters 50 (2009) 2885-2888. However, the use of such a complex for delignification and bleaching of paper pulp there is not described and not offered.

Processing stage hydrogen peroxide, activated complex on the basis of molybdenum, involves adding a paper weight of hydrogen peroxide and complex on the basis of molybdenum or its predecessor. Stage of bringing into contact can be carried out in accordance with the variations of implementation.

It is possible, in particular, first obtain an aqueous solution of the complex on the basis of molybdenum, introducing the predecessor of the specified complex in an aqueous solution of hydrogen peroxide, then add this solution into a paper weight.

It is also possible to add in pulp complex of molybdenum, on the one hand, and hydrogen peroxide, on the other hand. Complex of molybdenum, in particular, to introduce in the form of an aqueous solution.

It is also possible to enter a paper weight of the precursor complex on the basis of molybdenum, on the one hand, and per XID hydrogen, on the other hand, so that the complex on the basis of molybdenum was formed in situ in the paper pulp. The precursor complex on the basis of molybdenum, in particular, to introduce in solid form or in aqueous solution.

The specified precursor is, for example, the complex CpMo(CO)3(C≡CPh), where Cf denotes cyclopentadienyls group, and Ph denotes a phenyl group. Preferably we are talking about tricarbocyanines-molybdenum (VI). Can use other predecessors, provided that they provide education specified complex of molybdenum in the paper pulp.

Working conditions (consistency mass, time, temperature, etc.) under treatment with hydrogen peroxide and complex on the basis of molybdenum and its predecessor are as described above.

The amount of lignin in the paper pulp can be measured using the kappa index in accordance with ISO 302 from July 1987

More or less satisfactory protection of the cellulose in the paper pulp can be characterized by the degree of polymerization. It is calculated on the basis of viscosity measurements paper pulp using a capillary viscometer (TAPPI test method T 230 om-08).

The consistency of the mass corresponds, as mentioned above, the concentration of mass, as defined in the ISO 4119 June 1996. It is measured in accordance with the tvii with this standard.

The hydrogen peroxide remaining after the processing stage can be determined by iodometric titration. This method can be done as follows:

at the end of the processing stage of the pulp is filtered in accordance with ISO 4119. To the filtrate is added a solution of sulfuric acid (300 g/l) and a solution of potassium iodide (100 g/l). Iodide of potassium is oxidized by hydrogen peroxide, releases in the filtrate died. After that start the titration of released thus diode by successive additions of sodium thiosulfate solution (24.8 g of Na2S2O3, 5H2O/l) in the leachate.

If after processing stage remains of hydrogen peroxide, this means that processing can continue to enhance delignification and bleaching or, if possible, to reduce the initial amount of hydrogen peroxide.

EXAMPLES

The following examples illustrate the invention but without limiting it.

Comparison of the invention with a method of bleaching of the level of technology

As raw material in the following tests using chemical pulp from Northern Europe, which previously delignification oxygen. Initially, this mass has a kappa index of 11.3 and a degree of polymerization 1540.

In paper weight enter the water if the este, sufficient to obtain a consistency of 10% of the mass. dry weight relative to the weight of dry pulp.

These three parameters determine the methods specified above.

Test 1: processing complex on the basis of molybdenum according to the invention

Sample paper pulp containing 20 g of dry paper pulp is introduced into a plastic bag.

Consistently in the sample is injected (in mass percentage relative to the total weight of dry paper pulp):

0.4 g (2 wt. -%) NaOH,

0.01 g (0.05% wt.) tricarbocyanines-molybdenum (VI)

0.4 g (2 wt. -%) H2About2.

Complex on the basis of molybdenum, oncoproliferative-molybdenum (VI), is formed in situ in the paper pulp. It is present in the amount of 0,044% of the mass. in relation to the total weight of dry paper pulp, provided that the transformation of precursor introduced into the sample is complete.

The package is sealed by termocline and manually shaken for homogenization of the mixture. They are immersed in a water bath at a temperature of 50°C for 3 hours. The package is extracted and the resulting pulp is filtered through a Buchner filter (in accordance with ISO 4119 June 1996) to separate the filtrate from the precipitate, consisting of fibers.

Measure:

the pH of the filtrate,

the hydrogen peroxide remaining in the filtrate by the method above, iodine is the metric titration,

the kappa index of sediment, consisting of fibers,

the degree of polymerization of the precipitate, consisting of the fibers.

Test 1 bis: preliminary obtaining the solution of the complex on the basis of molybdenum according to the invention

Receive an aqueous solution containing 0.4 g of N2About2in 50 ml of water. In the resulting solution is injected 0.01 g predecessor tricarbocyanines-molybdenum (VI) in solid form. The resulting mixture was shaken to dissolve the predecessor within 1-2 minutes.

Thus, get the solution of the complex on the basis of molybdenum oncoproliferative-molybdenum (VI).

Apply methods similar to example 1, treating the original sample paper pulp containing 20 g of dry paper pulp (in mass percentage relative to the total weight of dry paper pulp):

0.4 g (2 wt. -%) NaOH and

the solution of the complex on the basis of molybdenum obtained in this way.

Test 2 (benchmark test): processing only hydrogen peroxide

Apply methods similar to example 1, treating the original sample paper pulp containing 20 g of dry paper pulp (in mass percentage relative to the total weight of dry paper pulp), using:

0.4 g (2 wt. -%) NaOH and

0.4 g (2 wt. -%) H2About2.

Test 3 (comparative test): processing complex methanotrophic

Apply methods similar to example 1, treating the original sample paper pulp containing 20 g of dry paper pulp (in mass percentage relative to the total weight of dry paper pulp), using:

0.4 g (2 wt. -%) NaOH,

0.4 g (2 wt. -%) H2About2and

0.01 g (0.05% wt.) complex copper-phenanthroline Cu(phen)2from WO 03/080925.

Test 4 (comparative test): treatment with ammonium molybdate

Apply methods similar to example 1, treating the original sample paper pulp containing 20 g of dry paper pulp (in mass percentage relative to the total weight of dry paper pulp), using:

0.4 g (2 wt. -%) NaOH,

0.4 g (2 wt. -%) H2About2and

0.01 g (0.05% wt.) the molybdate ammonium of the formula (NH4)6Mo7O24, 4 H2O.

The whitening results are presented in the table below.

The kappa indexDynamic viscosity (mPa.s)The degree of polymerizationThe residual N2About2*pH
Sample paper pulp prior to bleaching11,3 26,01540xX
Sample paper pulp after bleachingTest 1: N2About2+complex on the basis of the Mo according to the invention7,3of 21.2140035%a 12.7
Test 2: only H2About29,120,4138055%12,4
Test 3: H2About2+complex Cu(phen)26,411,39801%12,5
Test 4: N2About2+ammonium molybdate8,29,38501%12,5
*The content of residual hydrogen peroxide is given in mass percent relative to the total mass of peroxy the and hydrogen, originally introduced in the sample paper pulp.

These results show that:

the use of ammonium molybdate (test 4), despite the fact that it gives an advantage on cost of production, does not improve compared to the use of a complex copper-phenanthroline (test 3): he delignified to a lesser extent, also destroying the cellulose. This test shows that only the presence of transition metal molybdenum in the activator is not sufficient to improve performance bleaching;

Complex of molybdenum according to the invention (test 1):

allows you to activate hydrogen peroxide during delignification (kappa index less than in test 2),

protects cellulose (degree of polymerization, which is close to the initial value, and clearly higher than in trials 3 and 4),

reduces the decomposition of hydrogen peroxide (the content of residual hydrogen peroxide higher than in trials 3 and 4).

Mass processed by the method according to the invention, obtained at the end of test 1, then:

sent in paper machine for direct drying and cutting into sheets; or

goes into the machine for pressing the mass to drying and preliminary molding in the form of sheets stacked in piles to move on bumagodelatelnoe the factory for further processing.

1. The method of delignification and bleaching of paper pulp, comprising at least one stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of molybdenum formula (I):
(I)
where
R denotes unsaturated C5-C6-cycloalkyl group or unsaturated C5-C6-geterotsyklicescoe group, substituted or unsubstituted, and
Ar denotes an aryl group optionally having one or more substituents in the aromatic () the ring(s)representing one or more linear or branched C1-C4-alkyl groups, -halogen, -NO2, -OH, -COOH.

2. The method according to claim 1, in which R denotes a C5-cycloalkenyl or C6-aromatic group, preferably cyclopentadienyls group.

3. The method according to any one of claims 1 or 2, in which Ar denotes a phenyl group.

4. The method according to any one of claims 1 or 2, in which the complex of molybdenum is oncoproliferative-molybdenum (VI), formula (II):
(II)

5. The method according to any one of claims 1 or 2, in which the pH of the paper pulp adjust to a value from 7 to 12, preferably from 7 to 11 at the stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of molybdenum, preferably by adding sodium hydroxide.

6. Spasibo any one of claims 1 or 2, in which stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of molybdenum is carried out at a temperature from 10°C to 120°, preferably from 20°to 100°C., more specifically from 30°C to 80°C.

7. The method according to any one of claims 1 or 2, in which stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of molybdenum lasts from 1 minute to 4 hours, preferably from 30 minutes to 3 hours.

8. The method according to any one of claims 1 or 2, in which the consistency of the paper pulp during the stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of molybdenum is from 1% to 40% of the mass. dry paper pulp, preferably from 5% to 30% of the mass. dry paper pulp, in relation to the total dry weight of pulp.

9. The method according to any one of claims 1 or 2, in which the initial quantity of hydrogen peroxide at the stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of
molybdenum is less than or equal to 10% of the mass. dry paper pulp, preferably less than or equal to 4% of the mass. dry paper pulp and more specifically in amounts from 0.1% to 2% of the mass. dry paper pulp.

10. The method according to any one of claims 1 or 2, in which the number of the complex on the basis of molybdenum at the stage of bringing into contact paper pulp with hydrogen peroxide and complex on the basis of molybdenum SOS the place from 0.001% to 1% of the mass. dry paper pulp, preferably from 0.01% to 0.2% of the mass. dry paper pulp.

11. The method according to any one of claims 1 or 2 includes:
obtaining an aqueous solution of the complex on the basis of molybdenum interaction of the precursor complex on the basis of molybdenum and aqueous hydrogen peroxide, followed by addition of an aqueous solution of the complex on the basis of molybdenum in the pulp; or
adding a paper weight of the precursor complex on the basis of molybdenum.

12. The method according to any one of claims 1 or 2, including the introduction to a paper weight of the precursor complex on the basis of molybdenum formula CpMo(CO)3(C≡CPh), where Cf denotes cyclopentadienyls group, and Ph denotes a phenyl group, preferably represents tricarbocyanines-molybdenum (VI).

13. The method of obtaining and processing of paper pulp, including:
the first stage of penetration is required before timber, preferably in the presence of sodium hydroxide and sodium sulfide to obtain paper pulp;
optional preliminary stage of delignification and
the bleaching of paper pulp with oxygen;
the delignification and bleaching of paper pulp by the method according to any one of claims 1 to 12;
optional stage delignification and bleaching of paper pulp by alkaline extraction and/or treatment with ozone, and/or treatment of peracetic acid is, and/or bringing into contact with the hydrogen peroxide and/or chlorine-containing compound, such as chlorine dioxide.

14. The method of obtaining the paper, including the receipt and processing of paper pulp by the method according to item 13 with subsequent cutting into sheets and dried.



 

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12 cl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: absorbent material is made by treating lignin-cellulose material in the presence of a catalyst from a transition metal with oxidation. The oxidising agent is selected from a group consisting of hydrogen peroxide, hypochlorite, hypochloric acid or any combination thereof. The lignin-cellulose material is treated at pH from approximately 2 to approximately 6. The treated lignin-cellulose material has viscosity equal to or less than approximately 17 cP. The treated lignin-cellulose material is subjected to dry grinding. The dry ground lignin-cellulose treated material is used as an absorbent intermediate layer for making absorbents.

EFFECT: improved bacteria inhibition properties.

2 cl, 17 ex, 16 tbl

FIELD: paper industry.

SUBSTANCE: cellulose containing material from herbaceous plants is soaked in alkaline solution, washed, bleached, again washed, squeezed and dried. After soaking thermal-mechanical-chemical treatment is carried out in double-auger device, which consists of heated working chamber with impermeable wall and two parallel joined shafts arranged in it. Alternating injection auger and grinding cam tips are installed on shafts. At the same time prior to washing they additionally execute thermal-mechanical-chemical treatment in double-auger device, on shafts of which there are alternating injection and braking auger tips.

EFFECT: invention provides for cost-efficient method of cellulose making.

2 cl, 1 tbl

FIELD: textile, paper.

SUBSTANCE: method is referred to bleached wood pulp production from hardwood chips for their further use in different compositions for paper and cardboard production. Chipped wood is impregnated with alkali solution of sodium sulfite. Spent impregnating solution is then removed. Chipped wood is milled in two stages. In between components are treated by alkali solution of hydrogen peroxide at weight concentration 14-18% and final pH=9.5-10.0. Following the second stage of milling, pulp is dissolved to concentration 3.0-5.0% and cured during 30-60 minutes to pH=7.5-8.0. Pulp is chemically treated by alkali solution of hydrogen peroxide between milling stages at 75-85°C during 15-20 minutes.

EFFECT: decrease of chemicals consumption for impregnation and improvement of mechanical and optical properties of target product.

2 cl, 1 tbl, 4 ex

FIELD: paper-and-pulp industry.

SUBSTANCE: cellulose delignification process comprises alkali treatment, delignification with hydrogen peroxide with sodium hydroxide and sodium silicate additive, and acid treatment. Alkali treatment consumes 0.5% hydrogen peroxide and 2.0% sodium hydroxide based on the weight of absolutely dry cellulose and is conducted for 2.0-2.5 h at 60-90°C. Acid treatment of delignified product is accomplished with aqueous hydrochloric acid, which is consumed in amount 1.0% based on the weight of absolutely dry fibers, while treatment is conducted for 30-60 min at ambient temperature.

EFFECT: enhanced economical efficiency without loss cellulose characteristics.

2 tbl, 11 ex

FIELD: chemistry.

SUBSTANCE: invention relates to methods of obtaining cellulose and low-molecular weight oxygen-containing compounds from processing biomass from forestry and agricultural wastes. The method of processing biomass involves heating water to 58-75°C, adding FeCl3 × 6H2O, holding the solution at 58-75°C for not less than 10 minutes while stirring continuously. After complete precipitation of Fe3+, the biomass is added with ratio of water to biomass of 10-20; the mixture is stirred and held for not more than 10 hours. Hydrogen peroxide is then added with ratio of hydrogen peroxide to biomass of 3.5:0.5; the mixture is stirred at temperature of 25-70°C until hydrogen peroxide is exhausted. The obtained oxidate is separated into a solid precipitate and a solution of water-soluble products. The solid precipitate is washed with water, which is then used in the next cycles and/or is added to the aqueous solution of water-soluble products. Versions of the method involve further addition of 1-10% lower alcohol to water and/or addition of soda to FeCl3 × 6H2O with weight ratio of iron chloride and soda of 1.5-80. Versions of the invention enable to combine synthesis of a catalyst and oxidative processing of biomass in a single cycle (reactor). Output of water-soluble products and solid precipitate (cellulose) can be controlled depending on the ratio of the catalyst and the biomass. The water-soluble products contain organic acids and polyphenols, which can be used as preservatives and biological additives in producing feedstuff in agriculture.

EFFECT: reducing water consumption by about an order, as well as consumption of energy and components.

15 cl, 1 tbl, 9 ex

FIELD: textiles, paper.

SUBSTANCE: production processes of mechanical wood pulp using refiners are disclosed, and more particularly, the wood-pulp plant is disclosed which is integrated with the neutral-alkaline processes of paper production, generating printing paper from mechanical wood pulp. The waste products are treated with hydrogen peroxide, alkali and an organic stabilising additive immediately before or during refining, that provides improved optical and physical properties of the refined waste products and uses electrical energy more efficiently to achieve the desired quality of the fiber after bleaching for cost-effective production of a wide variety of coated and uncoated printing paper from mechanical wood pulp.

EFFECT: improvement of quality of rejected material.

4 cl, 2 tbl, 12 dwg

FIELD: textiles, paper.

SUBSTANCE: method for producing sulphate pulp from a mixture of chips from different species of wood includes the use of three batch cookers sequentially interconnected by liquid phases, their loading with a mixture of chips from different species of wood, including wood of larch, pine, spruce, birch, aspen, preliminary two-stage treatment of the mixture with water extraction at the first stage and black liquor at the second, removal of the extract from the cooker, supply to the cooker of cooking liquor, recycling the extract to obtain arabinogalactan. Both extraction treatments are carried out in three cookers interconnected by liquid phases by their sequential filling with each of the liquid phases with the removal of the aqueous extract by its replacement from the cookers by black liquor and the removal of the black liquor by its displacement by the cooking liquor.

EFFECT: alignment of the characteristics of chips from all types of wood and increase in the concentration of arabinogalactan in the aqueous extract.

4 cl, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: material is fed into a mixer 1 and treated with steam from a pipe 10. The treated material is then fed into a screw feeder 2 which is provided with valve locking device. The reactor 3 is in form of a vertical cylindrical vessel which is provided with means of loading and unloading material and a means of intensifying agitation of the reaction mass, having a pulsation chamber 4, which encloses the reactor 3, and a pulsator - pulse generator 12. Cooking liquor is fed into the reactor 3 through pipe 5. Spent cooking liquor is removed from the reactor 3 through pipe 6. Steam is fed into the reactor 3 through pipe 7, which is fitted with steam injectors. The reaction mass is subjected to acoustic energy pulses with frequency of 5-70 pulsations per minute with energy density of 3-100 MJ/mol. The pulsator - pulse generator 12 consists of a compressor 13, a receiver 14, a pipe 16 and a pulse generator 15. The reaction mass is moved into the top part of the reactor 3 and, using a blade or scrapping device 8 of a screw device 9, the ready product is separated from the cooking liquor to obtain the end product - edible cellulose.

EFFECT: simple reactor design and delignification technology, low power consumption, while improving quality of the cellulose mass.

3 cl, 3 dwg

FIELD: textiles, paper.

SUBSTANCE: method includes cooking of cellulose containing raw material in the presence of hydrogen peroxide, followed by alkali extraction and washing off. Carbon dioxide in the supercritical state is used as a medium, and the hydrogen peroxide is added in the form of a solution containing at least 30% hydrogen peroxide. Consumption of hydrogen peroxide for cooking is at least 65% by weight of oven-dry wood.

EFFECT: invention enables to produce cellulose wood pulp which has high mechanical strength, to improve the environmental situation near the manufacturing enterprises.

5 cl, 6 ex, 1 tbl

FIELD: textiles, paper.

SUBSTANCE: reactor vessel has an inlet to enter the cellulosic material and an outlet for discharging cellulosic material, and the cellulosic material flows through the reactor vessel from the inlet for the material to the outlet to unload the material; extracting sieve for hydrolysate and liquid; hydrolysis zone between the inlet for the material and extracting sieve for hydrolysate and liquid. Hydrolysis zone is maintained at a temperature of hydrolysis or above the temperature of hydrolysis at which the reaction of hydrolysis of the cellulosic material takes place. The reactor vessel contains the flush zone between the extracting sieve for hydrolysate and liquid and extracting sieve for flushing fluid, where hydrolysis is suppressed; an inlet pipe for flushing fluid to enter the flushing fluid in the flush zone. At least a part of flushing fluid flowing into the inlet pipe for flushing fluid flows through the flushing zone and is extracted with extracting sieve for hydrolysate and liquid, and the flushing fluid is entered into the flushing zone at a temperature below the temperature of hydrolysis. The reactor vessel contains a pulping area between the flushing zone and unloading zone for release of material, and the said pulping area includes a pipe for injecting of cooking liquor; and extracting sieve for cooking liquor in the pulping area or under the pulping area, and over the unloading release for the material, and the flushing fluid is a mixture of water and at least one of the substances, such as sodium hydroxide and white liquor, essentially free of sulfur.

EFFECT: reduction of risk of precipitation of lignin and other dissolved wood components, and reduction of consumption of alkali during the chemical pulping of cellulosic material.

40 cl, 1 dwg

FIELD: textiles, paper.

SUBSTANCE: whiteness of paper products of natural colour is 35-60% ISO, and for their production unbleached straw cellulose is used with a tensile strength of 230-280 mN, fracture strength with multiple bends of 40-90 times and permanganate index of 16-28. The composition of natural-coloured paper products includes sanitary and hygienic natural-coloured paper, paper towel of natural colour, paper for wipe of natural colour, paper for photocopies of natural colour, paper box for food of natural colour, natural-coloured wrapping paper for food products, and printing paper of natural colour.

EFFECT: strength of the above mentioned paper products is high, and when control over the content of harmful substances dioxin and adsorbable organic halides are not detected.

24 cl, 20 ex

FIELD: textiles, paper.

SUBSTANCE: method of delignification of wood chips is carried out in the digester during turbulisation of the pulp. For this a limited along the length fragment of the area of the brewing process in the digester is chosen, which is over the entire cross section of the stream of pulp is divided into a series of parallel and independent streams, in each of which turbulisation is created. The latter is carried out by periodic changes in the volume of each of the streams, which is implemented due to changes in cross-sectional area of these streams.

EFFECT: significant acceleration of delignification process, decrease in temperature of technological zones and pressure in them, and the reduced specific energy consumption of pulping, increased productivity of plants, weight and size characteristics of the digester are reduced several times.

3 cl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: raw material undergoes steam treatment before the cooking step. Cellulose obtained by cooking, undergoes cold caustic extraction (CCE) during subsequent treatment.

EFFECT: invention enables to obtain cellulose with high output and purity of the product, and avoid accumulation of hemicellulose in the bleaching filtrate.

21 cl, 7 ex, 9 tbl, 13 dwg

FIELD: oil and gas industry.

SUBSTANCE: synthesis method of multi-purpose self-adjusting catalyst for liquid-phase low-temperature oxidation cracking of organic raw material, including natural biomass, is described, and it consists in the fact that iron salt FeCl3 x 6H2O is dissolved in water containing lower alcohol in concentrations required for formation of colloid system capable of peptisation, at heating up to the temperature not exceeding 100°C and constant mixing so that suspension of colloid solid particles of iron oxides containing organic impurities is obtained. The above suspension can change its activity depending on type of organic raw material and oxidiser, and at cracking of natural biomass and in case the latter represents lignine or lignine-containing biomass it has properties of ferments in relation to lignine. Method of liquid-phase low-temperature oxidising cracking of organic raw material, including natural biomass, in presence of catalyst at atmospheric pressure is described. At that, air oxygen and/or hydrogen peroxide is used as oxidiser and the above catalyst is used as catalyst.

EFFECT: high-activity catalyst of liquid-phase oxidising cracking.

8 cl, 7 dwg, 11 ex

FIELD: paper-and-pulp industry.

SUBSTANCE: corn stems are reduced to fragment, boiled, ground, dispersed, flattened, and dried to produce paper sheets. Boiling is carried out for 1.5-4 h at ratio of aqueous solution of reagent to corn stem material between 3:1 and 6:1 and temperature 120-200°C.

EFFECT: achieved high quality of pulp, improved environmental condition, and reduced expenses.

5 cl, 2 tbl, 7 ex

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