Method of producing cellulose pulp

FIELD: technological processes.

SUBSTANCE: method of defibring lignocellulose-bearing raw material with a polysulphide-bearing cooking liquor in a boiler for continuous cooking. According to this invention, the cooking liquor is mixed into the raw material which is to be defibred before the cooking, and the cooking liquor is allowed to absorb into the raw material at a temperature which is at maximum approximately 130 °C. After that, cooking liquor used in the absorption is separated from the treated raw material, separated cooking liquor is heated to a temperature of approximately 140–170 °C, after which, the generated hot cooking liquor is mixed back into the treated raw material, possibly together with a fresh feed of cooking liquor, and raw material is defibred with a hot cooking liquor in the boiler for continuous cooking in order to produce cellulose pulp which has a desired kappa number. Thus, in the cooking stage, alkaline cooking liquor which originally was dosed into the absorption solution is used, but the temperature of which has been increased; absorption liquor is not removed, and fresh liquor is not fed into the boiler for continuous cooking or, it is fed, but only in a small amount.

EFFECT: disclosed is a method of defibring raw material.

18 cl, 2 dwg, 1 ex

 



 

Same patents:

FIELD: chemistry.

SUBSTANCE: method of the determination of lignin in cellulose semi-products by chemical processing with the following separation of lignin and determination of its quantity consists in the fact that chemical processing of a cellulose semi-product is carried out with 1 ml of a reagent, which is prepared by mixing concentrated nitric acid and dioxane in a ratio of 1:1 by volume, at heating on a boiling water bath for 5 minutes, with the determination of lignin being realised by means of spectrophotometry at 340 nm after preliminary alkalisation and separation of the cellulose residue that does not dissolve.

EFFECT: simplification and acceleration of the analysis performance.

1 cl, 14 ex, 1 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to processing of black liquor of cellulose plant for extraction of chemicals and power contained therein. Proposed process comprises feed of black liquor into pyrolysis reactor with, in fact, no oxygen space. Sand heated in boiler with fluidised bed is fed into said reactor to gasify said black liquor so that gaseous components and soli matter are formed. Gaseous components formed in pyrolysis reactor are directed for recovery. Sand is separated from solid matter formed in pyrolysis reactor and returned back into boiler with fluidised bed. Water is added to remained solid matter to dilute soda contained in solid substance. Formed soda-water solution is returned to cellulose coking and remained solid coal to boiler with fluidised bed. This plant comprises the boiler with fluidised bed, pyrolysis, sand feeder, means to direct gaseous components, sand separator from solid matter, means to return separated sand, mixing reactor, means to return soda-water solution to cooking process and remained solid coal to boiler with fluidised bed.

EFFECT: extraction of chemicals and power in one cycle, increased volume of formed gases.

31 cl, 4 dwg

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

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: 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 20°C 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 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: 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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