Peroxide-alkaline treatment of waste products on integrated neutral-alkaline pulp and paper plant

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

 

The SCOPE of the INVENTION

The present invention is directed to processes for the production of mechanical wood mass, using the refiners to improve the quality of rejects, and, more specifically, drivesnapshot plant integrated with a neutral-alkaline paper manufacturing process for the production of varieties of printing paper from mechanical pulp. To ensure superior optical and physical properties of refined waste, waste is treated with hydrogen peroxide, an alkali and an organic stabilizing agent.

BACKGROUND of the INVENTION

Obtaining wood pulp is a process of mechanical grinding of wood in its fiber for the manufacture of wood pulp. A key advantage of pulping is a high yield in comparison with obtaining chemical wood pulp, which removes most or all of the lignin that binds the cellulose fibres. Machined wood lignin is not removed, and this implies that scarce resources are used more efficiently. Wood pulp, manufactured using traditional methods of obtaining mechanical wood mass, mainly used for newsprint and other printing paper, intended for direct mail advertising, kata is taxes and some magazines and books, and, as a rule, unsuitable for higher quality or more durable final paper products. This is partly due to the fact that the mechanical wood pulp, generally harder bleached, can be returned to its original state in relation to the degree of whiteness under the action of light and moisture and, as a rule, are of lower strength than chemical pulp.

There are many options for obtaining mechanical woodpulp, including groundwood pulp (SGW), press groundwood pulp (PGW), refined mechanical pulp (RMP), thermomechanical pulp (TSR) and chemotherapeutically wood pulp (STMR). The last three types can be further grouped into General processes for the production of refined wood mass. In the course of obtaining refined woody masses chips ground between the rotating metal disk. Usually the process is carried out in two stages. The first stage is mainly used to separate the fibers, while the second stage is used for surface modification of fibers to improve the sizing of the fibers in the paper manufacturing process.

The preceding list is by no means exhaustive. There are countless combinations and options% Sov pulping. Among the processes of pulping TSR process is considered by many experts as the most preferred, whereas the situation of the market and norms of environmental protection.

TSR-the process usually consists of two stages of refinement. The first stage is carried out under pressure, which allows the capture of thermal energy released in the form of steam under the application of mechanical energy to the chips between two rotating refiner plates. Control of steam pressure allows the primary refiner to operate at elevated temperatures and provides steam for heating and humidifying of wood chips prior to refining. The second refiner stage can operate at atmospheric pressure, but more common is the second stage is also under pressure in order to capture more energy and better manage the process. Wood pulp manufactured TSR and STMR processes, are more durable, making these processes more preferred processes for mechanical wood mass. However, there is additional potential for improvement. TSR-the process consumes large amounts of electricity, and wood pulp obtained TSR process, tends to be darker than most each the x wood mass due to thermal darkening of the fibers during refining. In addition, the presence of large quantities of refined lignin fiber makes it visokovostrebovan to alkaline darkening.

All processes produce mechanical wood pulp rejects further processed to improve their favorable properties (e.g., ability to bonding) and to make them more attractive as a fiber for papermaking machines. Waste treatment mechanical wood pulp and sodium sulfite (sulfonation waste) before refining showed what can be achieved improving durability. However, the loss of degree of whiteness during refining and the increase in BOD and COD of wastewater, and energy refinement make it unattractive for commercial practice.

The use of peroxide-alkaline waste treatment mechanical wood pulp, as shown, leads to improved physical properties and a higher degree of whiteness, equal to or exceeding that of when the sulfonation. However, the effective peroxide-alkaline processing to maximize improvements, as described, require processing time from five to forty minutes or more. See, for example, "HIGH ALKALINE PEROXIDE TREATMENT OF WHITE SPRUCE/LODGEPOLE PINE RMP REJECTS', S.G.Book, pp1-17, CPPA Pacific Coast Brach Mini-Conference April 1990 and ALKALINE PEROXIDE TREATMENT OF SOUTHERN PINE TMPREJECTS", M.J. Sferrazza et al., pp 617-629, 1988 Pulping Conference. In the described processes for waste treatment was used 4,4-8.9 wt.% NaOH per fiber to achieve noticeable improvements in physical strength and the ratio of caustic/peroxide (C/R)2-3:1.

In "OPTIMIZATION OF IN-REFINER BRIGHTENING WITH H2O2FOR PRODUCTION OF HI-BRITE MECHANICAL PRINTING PAPER", V.Simard et al., pp 1-10, 1995 CPPA Spring Conference of the Pacific Coast and Western Branches, disclosed the use of peroxide-alkaline waste treatment without cooking time or retention time in the RMP process, and discovered that it requires the addition of 3.0 wt.% caustic or more. The system described in Simard et al., used a recirculation flow rate of waste water to the TSR-plant with pH 5.0-5.5, because the paper machine, integrated with it, worked within this interval.

Later improved waste TSR and reduction of specific energy refining by adding peracino-alkaline solution before refining waste was discussed in conjunction with the production of grades of printing paper from mechanical pulp with added value in IMPROVING TMP REJECTS REFINING THROUGH ALKALINE PEROXIDE PRETREATMENT; AN OPPORTUNITY FOR SCA PAPER?", Y.Bian et al, 2006 PAPTAC Pacific Coast Branch Spring Mini-Conference. However, as in previously published studies, including the processing of fibres from softwood, it was found that to achieve the desired fiber quality (for example, durable and the STI in the gap, reduce krupnodernytsi fiber softwood) and savings in operational costs (for example, reduction of specific energy refining, reducing the need for chemical fiber during the manufacture of paper) before refining requires combined use of alkali over 5.2 wt.% and the reaction time is 30 minutes, concentrated on the fiber at an elevated temperature.

Publication of U.S. patent No. 2009/0032207 discloses a mechanical or chemimechanical the process of manufacturing wood pulp, in which, after fibrillatory wood pulp bleached in alkaline conditions. After that waste is sorted and bleached separately from the conditioned pulp, and bleached waste is mixed with conditioned mass.

Publication of U.S. patent No. 2008/0035286 discloses peroxide-alkali process to obtain mechanical wood pulp, which includes the step of processing loose wood-pulp material peroxide-alkali chemical product for some time and under conditions sufficient to obtain a pulp of the desired concentration.

"Whitening" is a term associated with the process of pulping, where certain chemicals are thoroughly mixed with the fiber, and then held on the fiber for a given amount of time with the aim of increasing the largely white pulp. Bleaching is practiced on the chemical and mechanical fibrous wood mass. When receiving mechanical wood mass increase of the degree of whiteness is achieved by changing the chemical structure of conjugated double bonds in lignin. Compounds with conjugated double bonds are called chromophores. "Lightening" is a term often used in relation to bleaching mechanical wood mass to mark its difference from the process of bleaching chemical wood mass, which is characterized by destruction of the whole lignin. Hereinafter, the term "bleaching" will be understood as covering also the process of "clarification".

In mechanical wood mass bleaching is often performed on a single stage in the process of pulping. The whitening process is traditionally held on the bleaching station in one or more tanks (bleaching towers or stages) in a separate section of the plant in contrast to section pulping plant. Bleaching may be carried out using oxidizing agents such as hydrogen peroxide and/or reducing agents, such as dithionite sodium or hydrosulfite sodium.

Typically, hydrogen peroxide, oxidizing agent, is used with sodium hydroxide. Sodium hydroxide is a strong alkali and provides treb is radiated high pH value, required to obtain active perhydroxyl-ion battery, the IEO-with the aim of obtaining a bleaching effect in wood mass. The cost of sodium hydroxide increases due to changes in availability and cost of energy. Concern about environmental problems also implies the reduction of sources of available sodium hydroxide. Therefore to find suitable alternatives to bleaching solutions and bleaching processes with limited commercial success tested other sources of alkalis and other methods.

To maximize the stability of the ions of hydrogen peroxide and perhydroxyl ion in the course of bleaching mechanical wood pulp, before adding in the time of adding hydrogen peroxide to the fiber, the fiber is generally used sodium silicate and one of the many organic and inorganic stabilizing agents. These materials are most beneficial because of their ability to control metal ions, such as manganese, iron and copper which are contained in the chips received in the process of pulping. In the absence of processing ions of these metals destroy hydrogen peroxide and perhydroxyl-ion before they will acquire the ability to lighten the chromophores, which makes the process much less efficient and reduces the effectiveness of the svetlenija.

Despite the fact that in most parts of previously published works relating to the addition of alkaline peroxide waste screening refiner, discussed the addition of sodium silicate, the present invention specifically excludes the use of sodium silicate for stabilizing peroxide and perhydroxyl-ion battery. The presence of silicates can lead to the formation of deposits (for example, calcium silicate, sodium carbonate), for example, grinding discs of the refiner, which may limit the ability of the refiner for refining waste. The exception of sodium silicate in the present invention avoids this potential difficulties.

A BRIEF DESCRIPTION of GRAPHIC MATERIALS

figure 1 - histogram of the degree of white refined rejects ISO on the basis of Example 1.

Figure 2 - graph of degree of whiteness refined rejects ISO from the percentage of peroxide-based Example 1.

Figure 3 is a plot of the thickness of the refined rejects from the caustic on the basis of Example 1.

4 is a graph of degree of whiteness according to ISO from the applied peroxide in the whitening sorted mass TSR on the basis of Example 1.

5 is a graph of the percentage reduction in thickness of the paper, the percentage increase in tensile strength compared to the base line of APTR with increasing C/P the conditional mass of rejects on the basis of Example 2.

6 is a graph of the percentage of fiber is softwood because APTR with increasing C/P the conditional mass of waste sortirovannye and sorted mass TSR-based Example 2.

7 is a graph of the percentage reduction in the thickness of the paper and the percentage increase in strength in comparison with the baseline with increasing C/P sorted mass TSR-based Example 2.

Fig - graph degree of whiteness, measured at different points in the mass passing through the TSR-mill, before, during and after the 7-day test APTR C/R of 1.0 on the basis of Example 2.

Fig.9 is a graph of the total energy density refining waste from sagasti end of waste in comparison with the absence APTR after a 7-day trial APTR C/R of 1.0 on the basis of Example 2.

Figure 10 - graph of interrupts on the wet parts depending on the day for all paper machines in a downward direction before, during, and after the 7-day test APTR C/R of 1.0 on the basis of Example 2.

11 is a graph of the key properties of the wood pulp sample wood pulp, selected on the release of the refiner waste after applying the average dosage of hydrogen peroxide, based on Example 3.

Fig - graph of the key properties of the wood pulp sample wood pulp, selected on the release of the refiner waste after application of higher doses of peroxide is odorata, on the basis of Example 3.

DETAILED description of the PROCESS

The present invention is directed to improvements in the processing of fibers from the waste produce mechanical wood pulp, which uses the processing of alkaline hydrogen peroxide, which does not require retention time on the fiber before the highly concentrated refining and which is effective at low levels of chemical processing. Use zero retention time adding products to an alkaline treatment to the thickened waste before refining how it was discovered, is effective when the degree of correlation between dobavlenny caustic, less than or equal to 3.5 wt.% pulp and paper mills, which involve at least one integrated neutral-alkaline papermaking machine and recycle water from her back to drivesraunchy plant. In this specification, percentages are given in weight percent, unless specifically stated otherwise. Elimination of requirements retention of alkaline peroxide on the fiber from the waste before refining allows the present invention to be implemented with minimal capital costs. Recycling waste water neutral-alkaline papermaking machine on drivesraunchy plant and the associated emergence of buffer properties is due to the filling of the pigment, precipitated calcium carbonate (PCC) or encodemessage of carbonate calcium (GCC), minimizes operating costs of chemical products by reducing the need for mechanical fiber in alkali. This leads to a smaller addition of the total quantity of alkali to the waste. The quantity of hydrogen peroxide added to processed with alkali waste, correlates with the addition of caustic, therefore reducing the requirements for the number of caustic soda reduces the requirements to the amount of hydrogen peroxide and makes the process more cost effective.

If scenario "zero retention time", which includes peroxide in alkaline processing waste (APTR), caustic and hydrogen peroxide can be added directly to the refiner waste or waste stream wood pulp, leaving the thickener waste, or in any of the available insertion point between two specified positions. For the maximum increase of the degree of whiteness of the ratio of caustic soda and peroxide (P), as a rule, is about 0.35 to 0.75. To maximize the strength of the C/R, as a rule, is about 1.25 to 1.5. The combination of simultaneously improving the degree of whiteness and strength can be achieved at intermediate sootnosheniyah C/R on the basis of the private requirements of a particular installation.

In this description it is understood that "alkali" includes any source of alkaline properties, such as, for example, sodium hydroxide or caustic soda (NaOH), sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3). Na2CO3and NaHCO3also provide buffering preventing vibrations in a wide pH range. When peroxide-alkaline bleaching is carried out at high temperatures, improved degree of whiteness is obtained with the buffer systems. Giving the system a buffer properties with less than a high pH (preferably from about 9 to about 10.5) prevents the decomposition of the peroxide and darkening, but still provides adequate alkaline properties to obtain the desired compounds. If necessary, the buffer releases the alkaline properties and provides sufficient alkalinity to slow and even get perhydroxyl ions. In waste water of neutral-alkaline papermaking machine, which uses filler pigment PCC or GCC, as the buffer does calcium carbonate, which is expected to improve lighting during APTR occurring in high-temperature refiner. Adding to the fiber before the reject refiner or refiner waste components of the solution APTR can be added separately or simultaneously, where "simultaneously" means that two or more components are added together as a prior is entrusted mixed stream, and "separately" means that one at a time as separate threads.

When using a pre-mixed solution for APTR-processing, it can be included stabilizer peroxide wardrode, such as, for example, a suitable chelating agent. Chelating agents may include, but are not limited to, aminopolycarboxylate acid, (for example) ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), nitrilotriacetic acid (NTA); phosphonic acid, (for example) ethylenediaminetetramethylene acid (EDTMP), diethylenetriaminepentaacetate acid (DTPMP), nitrilotrimethylphosphonic acid (NTMP); polycarboxylic acid, gluconate, citrate, polyacrylates and polyaspartate or any combination of them. Chelating agent may be added to the bleaching solution in an amount up to 0.5 wt.% per fiber, but preferably is added with degrees of adding from about 0.1 to 0.25% per fiber. Like all other components of the bleaching solution, chelating agents may be added separately or simultaneously with one or more components of the bleach solution at one or more points added chemical products in the refining system. It is assumed that chelating agents bind metals, preventing razloga the s of hydrogen peroxide, which can lead to darkening is made of paper.

Processing waste stream refiner alkaline peroxide that does not involve the exposure time, as it was discovered, provides increased strength and whiteness when economically significantly lower levels of processing caustic and hydrogen peroxide for systems that use the flow of recycled wastewater from neutral-alkaline papermaking machine as dilution water for drivesraunchy plant. Under neutral-alkaline" refers to a pH of from about 7.0 to 7.5. In addition, it was found that the neutral-alkaline waste water containing significant amounts of non-oxidized sulfur compounds, leads to higher degree of whiteness during APTR, which is lower than in the case when the neutral-alkaline waste water does not contain these impurities.

Now obviously, drivesnapshot combine with dilution in the process water obtained from a paper machine or paper machine operating at neutral-alkaline pH, but not at acidic pH, the need for caustic soda (and, thus, hydrogen peroxide) to achieve a given improvement of the quality of the fiber can be reduced to 20%. This is because the resin acids of wood, which are released from reveneu mass high output during primary and secondary stages of refining, partially neutralized by subsequent dilution of the waste water supplied from the waste water is neutral-alkaline papermaking machine. Together these disclosures generate the process that allows a neutral-alkaline pulp and paper mills for the production of printing paper from mechanical pulp to fit APTR to their process of obtaining mechanical wood pulp with appropriate minimum capital costs. In addition, it is now known that the process APTR when working in this way can eliminate the need for restorative lightening during a subsequent process. This will cause the wood mass with equivalente or superior optical properties and superior physical properties in paper machine with a neutral or positive impact on the cost of supply. In addition, if the wood pulp treated in this process APTR, it also can lighten traditional installation bleaching with hydrogen peroxide, producing wood pulp, which has: a) superior optical and physical properties are already achievable for interval degree of whiteness at a lower cost, or b) is equivalent to the optical and physical properties at equivalent cost to a higher step interval is either white, the range attainable at the moment. Also, through APTR functioning is described here by way of an adverse impact on fiber properties, such as, for example, loss of output, and the degree of whiteness, are minimized between Grevenmacher mill and paper machine while minimizing the loading of anionic charges in the paper machine and the load of BOD and COD of the wastewater. In addition, there is evidence that through APTR specific energy refiner waste depending on sagasti can be controlled more accurately, realizing savings on operating costs.

Examples

Example 1

A production test was conducted on the integrated neutral-alkaline pulp and paper mill for the production of printing paper from mechanical pulp, izgotavlivaem a number of varieties of paper having a degree of whiteness of 57.5-80% ISO in accordance with specifications and the opacity of the print 91,5-96% according to the technical conditions. Conducted fourteen trials that included simultaneous mixing of concentrated DTPA, NaOH and H2O2in dilution water and quick addition of this solution through a nozzle to dilution water in the hole refiner waste TMP. Chelating agent (DTPA) was additionally added before thickening and SOR is the use of waste with a constant degree add 1.5 kg of absolutely dry ton (kg/AST).

Adding 10, 20, 30 or 40 kg/AST peroxide per 100% was studied to determine the influence on the optical and physical properties of the fiber, as the ratio C/R was varied for each added share peroxide. Share dobavlenny DTPA per fiber was maintained constant. Table 1 summarizes the various combinations of DTPA, NaOH and H2O2used in the refiner.

Table 1
no trialNaOH (C)/H2O2(R)NaOH, kg/ASTH2O2kg/ASTDTPA kg/AST
1001,0
20,55,010,01,0
30,757,510,01,0
40,510,020,01,0
5 1,010,010,01,0
60,515,030,01,0
70,7515,020,01,0
81,515,010,01,0
91,020,020,01,0
100,7522,530,01,0
111,030,030,01,0
121,530,020,01,0
130,520,040,01,0
14 001,0
15000

Samples of refined waste (including core samples that received no added chemicals) was mixed with conditioned weight of the line, and determine the properties of the mixture. Some mixtures of refined waste and conditioned the masses OSVETLENIE hydrosulfite sodium or hydrogen peroxide to determine the savings in bleaching chemicals, When applied to a waste of 22.5 kg/AST NaOH and 30 kg/AST H2O2the tensile strength of conditioned pulp/waste increases by 5-10%, the thickness of paper from the conditioned pulp/waste reduced by 5-10%, whiteness conditioned pulp/waste is growing at 4-6% ISO, and the use of hydrosulfite when lightening is reduced by 100%, the use of caustic and peroxide when precisam lightening reduced by 10-15%, and decreases associated SO2for kislovka as reduced alkaline and peroxide remains after clarification.

In Figures 1-4 summarizes the relationship observed after APTR on the fiber obtained from the laboratory sheets of paper handmade character, alum is certain of the refined rejects, and the clarified samples purified mass TSR.

Example 2

Tests were conducted on integrated neutral-alkaline pulp and paper mill for the production of printing paper from mechanical pulp, izgotavlivaem a number of varieties of paper having a degree of whiteness 58-84% ISO in accordance with specifications and the opacity of the print 85-97% according to the technical conditions. During long periods of work in 12 hours and, separately, 7 days evaluated APTR by applying a solution containing dilution water, DTPA, caustic soda and hydrogen peroxide on the source of raw materials for the two refiners waste, operating in parallel.

12-hour assessment allowed: a) to compare the results from two different points add near refiners, b) to evaluate and low (0.6) and secondary (1,0) the ratio C/P with the constant addition of hydrogen peroxide of 30 kg/AST to determine the effect on fiber quality of the various provisions on TSR-mill, where there are these refiners waste, and (C) determining what impact APTR on the specific energy refining wastes.

When S/R of 1.0 with the addition of 30 kg/AST peroxide waste produced 7-day and 24-hour daily assessment, and which allows the waste water of the paper machine to return TMP-plant, making a complete revolution, b) evaluated the effect is of APTR at bleaching TSR on paper machines in the downward direction for different grades of paper, and (C) provided data showing a reduction in the specific energy in the refining wastes.

Table 2 summarizes laboratory data for samples conditioned masses sampled within one week of primary, secondary screening and sorting of waste, when two periods of work APTR the duration of 12 h each can be associated with three surrounding their work periods where APTR is not functioning.

Figures 5-7 illustrate the key advantages APTR on TMP-plant during the 12-hour test, while Figure 8-10 summarize the key results of continuous automated testing on TMP-plant and on three paper machines in a downward direction over an extended 7-day trial.

During the 12-hour and 7-day trials hydrosulfite designed for whitening TSR to a low degree of whiteness after functioning APTR within 4 hours no longer used in the downstream direction (when the impact of APTR on whiteness and pH stabilized relative to the baseline). Then, after work, APTR for 4 h, the degree of added peroxide and caustic soda in the running bleach plant was reduced by 50% equivalent to those that apply in the sorted weight TSR, and further optimization to achieve 100% reduction and equivalent expenses on chemical shall roducti was shown by the subsequent laboratory tests.

After 36 hours APTR whiteness on TMP-plant begins to fall, and the pH begins to rise, indicating that the waste water of paper machines has made a complete revolution, and, therefore, no longer needs the alkali to neutralize the acid properties of wastewater TSR. At this point, the C/P was decreased from 1.0 to 0.9, and remained unchanged for the remaining 48 hours of the test.

Example 3

Tests were conducted on integrated neutral-alkaline pulp and paper mill for the production of printing paper from mechanical pulp, izgotavlivaem a number of varieties of paper having a degree of whiteness of 58-60% ISO in accordance with specifications and the opacity of the print 85-95% according to the technical conditions. During long working periods for 12-36 h APTR was estimated by applying a solution containing dilution water, DTPA, caustic soda and hydrogen peroxide, in the dilution water supply high pressure added to the zone refining one or two refiners under atmospheric pressure, working consistently. These refiners process sorted, cleaned waste TSR, which was then otbelivanie separately from the additional conditional mass/waste TSR by hydrosulfite sodium and were used as reinforcing the ox is the Korean people's army on two paper machines in the downstream direction.

Figures 11 and 12 illustrate the beneficial effect APTR on whiteness, elastic and other key properties using correlations With/R in the range of 0.35-0.40 in solution for processing and DTPA used in unrefined waste before refining.

1. The method of mechanical processing of wood mass, which includes the following steps:
a) providing a cellulosic material derived from softwoods or hardwoods;
b) introduction of cellulosic material to the main system of the refinery for conversion into the main wood pulp;
c) separation of waste from primary wood pulp by screening or fractionation;
d) mixing (i) flow neutral-alkaline waste water is recycled from the paper manufacturing process, substantially not containing oxidized sulfur compounds and containing a buffering agent (ii) of working solution containing hydrogen peroxide and alkali, with these fibers from waste, where the amount of alkali is not more than 3.5 wt.% (100%) per fiber, and the ratio of alkali and hydrogen peroxide is from about 0.35/1.0 to about 1.5/1,0; and (iii) chelating agent to control metal ions that have a negative impact on the stability of hydrogen peroxide, with the specified waste during R is generowania.

2. The method according to claim 1, where the alkali is selected from the group consisting of sodium hydroxide, sodium carbonate or sodium bicarbonate.

3. The method according to claim 1, where the specified chelating agent is selected from the group which consists of aminoalkanoic acids, phosphonic acids, polycarboxylic acids, polyacrylates, polyaspartates, gluconate and citrate.

4. The method according to claim 1, where the specified buffer agent is selected from the group consisting of precipitated calcium carbonate (PCC) and finely dispersed calcium carbonate.



 

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8 cl, 7 dwg, 11 ex

FIELD: chemistry.

SUBSTANCE: water suspension of crushed aspen wood is put into a flow reactor and ozonised. Ozonation is carried out with concentration of ozone in the ozone-oxygen mixture equal to 90 mg/l, gas flow rate equal to 2-4 l/h and temperature of 20C and hydromodulus between 0.1:1.0 and 1.6:1.0.

EFFECT: high quality of the cellulose intermediate product, low consumption of reagents, high ecological cleanness of the process.

5 ex, 2 tbl

FIELD: woodworking industry.

SUBSTANCE: water medium, which comprises cooking base, is treated with gas mixture that contains sulfur dioxide. For this purpose device is used with tangential supply of water medium, which is equipped with porous element that separates it internal space into two longitudinal cavities. Gas mixture is supplied along one side of element and further to water medium through its pores under pressure of 0.6-1.2 MPa, and water medium is supplied along another side of element under pressure that is 0.04-0.06 MPa lower than pressure of gas mixture. Water medium is supplied in the form of main and additional flows. Water medium after its treatment with gas mixture is exposed to floatation cleaning with application of inertial gaseous part of processing products as flotator. Blower products from cooking boilers are supplied into water medium in process of its floatation cleaning.

EFFECT: increased efficiency of process and simplified process.

4 cl, 1 dwg, 3 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

FIELD: production of fibrous half-finished products at different degree of delignification; wood-pulp and paper industry.

SUBSTANCE: cellulose-containing vegetable material is subjected to boiling at higher sulfidity of boiling solution, up to 100%. Used as sulfide-containing component are alkaline wastes of oil desulfurization processes which contain inorganic compounds, including sodium sulfide at concentration up to 120 g/l in Na2O terms and residual organic compounds in form of sulfur-containing hydrocarbons C5-C6 and phenolates at concentration up to 15 g/l. Boiling is carried out at 130-160°C.

EFFECT: high parameters of delignification process; enhanced economical efficiency; reduction of toxic emissions.

2 tbl

FIELD: pulp-and-paper industry, in particular, production of sulfite cellulose.

SUBSTANCE: method involves mixing fir tree and hardwood chip; performing sulfite pulping of mixture and washing resulted pulp, with young thin birch wood being used as hardwood chip produced after wood care cuttings in an amount making 10-60% by total amount of raw wood material.

EFFECT: simplified method for producing of cellulose, wider range of raw material base and reduced cellulose production costs.

1 tbl, 8 ex

FIELD: textile fabrics, paper.

SUBSTANCE: it is intended for usage in pulp and paper industry. Invention contains processing unit for treatment of fibrous cellulose basic material, containing treatment tool for discharge of inclusion from basic material, grinding tool for basic material crushing for destruction in it nodes and decompose tool for decomposition lengthway of crushed basic material. It is used conveyor with pair of rotated in the same direction screws for treatment of crushed material into paper pulp, at that conveyor is devided into multitude of sections, facility for feeding of materials to be treated at least in one area and facility for temperature control and/or pressure at least in one of areas. Black liquor, formed during the process of paper pulp output, is treated in facility, containing evaporator for concentration of black liquor till containing of solid substance 30-70%, instrument for treatment of concentrated black liquor at temperature 300-650°C and encapsulated conveyor for transportation of concentrated black liquor from evaporator to instrument at temperature higher than 90°C. Invention also includes method, consisting in usage of described above facility.

EFFECT: creation of treatment advantageous process of fibrous cellulose basic material and treatment of black liquor.

39 cl, 5 dwg, 1 tbl

FIELD: textiles, paper.

SUBSTANCE: method refers to cellulose washing method and can be used in pulp and paper industry to obtain sulfite cellulose when producing paper and cardboard and chemical processing. Cellulose is rinsed with cold water in the presence of organic additive agent SAA of weakly anionic type - compound UMS-1. The present additive is water-based mixture of biodegradable ethoxylated fatty alcohols and non-chlorinated solvents. Additive consumption makes 0.005-0.02% of completely dry pulp weight.

EFFECT: enhancement of cellulose washing efficiency and pulldown of common and hazardous resin content in cellulose.

3 tbl, 15 ex

FIELD: paper industry.

SUBSTANCE: device comprises hollow cylindrical body with tightly attached bottom and cover. Body contains at least two porous elements, which are equipped with facilities for fixation to body, cover plug, facilities of tangential supply of liquid phase inside body, facilities of gas supply inside body, facilities for withdrawal of products of gas dissolution in water medium. All porous elements are equipped with facilities of tight fixation of them to each other by lateral sides and by end sides to bottom of body and cover-plug, and altogether they create tight regular volumetrical body, which creates longitudinal external and internal cavities in its internal space together with body walls, being communicated to each other only through pores of elements for separate supply of water medium and gas accordingly. Axis of internal cavity matches axis of body.

EFFECT: simplified manufacturing of device elements, unification of porous elements, simplified assembly of device and its maintenance.

4 cl, 3 dwg

FIELD: woodworking industry.

SUBSTANCE: water medium, which comprises cooking base, is treated with gas mixture that contains sulfur dioxide. For this purpose device is used with tangential supply of water medium, which is equipped with porous element that separates it internal space into two longitudinal cavities. Gas mixture is supplied along one side of element and further to water medium through its pores under pressure of 0.6-1.2 MPa, and water medium is supplied along another side of element under pressure that is 0.04-0.06 MPa lower than pressure of gas mixture. Water medium is supplied in the form of main and additional flows. Water medium after its treatment with gas mixture is exposed to floatation cleaning with application of inertial gaseous part of processing products as flotator. Blower products from cooking boilers are supplied into water medium in process of its floatation cleaning.

EFFECT: increased efficiency of process and simplified process.

4 cl, 1 dwg, 3 ex

FIELD: chemistry.

SUBSTANCE: water suspension of crushed aspen wood is put into a flow reactor and ozonised. Ozonation is carried out with concentration of ozone in the ozone-oxygen mixture equal to 90 mg/l, gas flow rate equal to 2-4 l/h and temperature of 20C and hydromodulus between 0.1:1.0 and 1.6:1.0.

EFFECT: high quality of the cellulose intermediate product, low consumption of reagents, high ecological cleanness of the process.

5 ex, 2 tbl

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 100C 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: 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

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