211results about "Pulp bleaching" patented technology

The invention discloses a method for preparing high-quality dissolving pulp from low-grade plant fiber raw materials, and belongs to the technical field of biomass pulping. The preparation method comprises the following steps: screening a low-grade plant fiber raw material to obtain a fiber raw material of which the length is 20-30 mm, the width is 10-15 mm and the thickness is 3-5 mm; carrying out deep prehydrolysis-sulfate cooking treatment on the screened fiber raw materials to obtain unbleached sulfate pulp fibers; performing deep eutectic solvent and elemental chlorine-free bleaching treatment on the unbleached sulfate pulp fiber to obtain paper pulp fiber with low kappa number; and carrying out biological enzyme treatment on the paper pulp fibers with low kappa number to obtain the high-quality dissolving pulp. According to the method, the morphology and the structure of chemical pulp fibers are effectively regulated and controlled by designing deep eutectic solvent treatment, and deep dissolution of residual hemicelluloses and lignin is achieved; through biological enzyme treatment, the alpha-cellulose content and the Fock reaction performance are further improved, and finally the high-quality dissolving pulp is prepared.

The present technology relates to fluff pulp having improved odor control and methods of making such fluff pulp. A fluff pulp is provided that includes bleached kraft fibers and a copper ion content of from about 0.2 ppm to about 50 ppm by weight of the bleached kraft fibers. The bleached kraft fibers include a length-weighted average fiber length of at least about 2 mm, a copper number of less than about 7, a carboxyl content of greater than about 3.5 meq / 100 grams; an ISO brightness of at least 80; and a viscosity of from about 2 cps to about 9 cps.

The invention discloses an chemi-mechanical pulp production method capable of improving the filtration property of chemi-mechanical pulp, and relates to the technical field of papermaking, high-concentration grinding freeness is optimized to 640 + / -30ml, pulp fine fibers can be controlled at 22%-33%, the tensile index middle-lower limit and the bulk middle-upper limit, the high-concentration grinding effect is improved, the effect between fibers is facilitated, the effect between the fibers and a grinding sheet is reduced, and the filtration property of the chemi-mechanical pulp is improved. Fiber cutting is reduced, and the content of pulp fine fibers is reduced; the MSD torque is increased to 250 + / -10 KNM, the tearing effect of wood chips is improved, the preimpregnation reaction of the wood chips is facilitated, the original fine content is controlled to 26%-29% from original 22%-33%, the pulp bulk is increased by about 0.1 cm < 3 > / g, and the tensile index is increased by 1.0 N.m / g; the four low-concentration grinders are changed into parallel connection, so that the residence time of pulp in the low-concentration grinders is prolonged, the cutting effect of the pulp ground by the low-concentration grinders on fibers is reduced, light friction between grinding sheets and the fibers is increased, fibrillation of the fibers is facilitated, the bulk and the tensile strength are improved to a certain extent, and under the content of fine fibers, the size of the fibers is reduced. And the bulkiness and the tensile index of the finished pulp are also improved to a certain extent.

The present application relates to pulping technology field, the present application provides a kind of high-strength high-cleanliness chemical pulp's pulping process, with bamboo willow edge scrap as fiber raw material, after 1 stage pre-steaming, chip washing, dehydration, 2 stage pre-steaming;The wood chip material after 2 stage pre-steaming is 1 stage extrusion and is dissolved, 1 stage chemical liquid pre-impregnation, 2 stage extrusion and is dissolved, 2 stage chemical liquid pre-impregnation;1 stage chemical liquid pre-impregnation uses sodium hydroxide solution and does not use hydrogen peroxide, the chemical reagent of 2 stage chemical liquid pre-impregnation process is sodium hydroxide, hydrogen peroxide and sodium silicate;Material after 2 stage chemical liquid pre-impregnation is 1 stage refining, separation, cooling, 1 stage high-concentration bleaching, 1 stage dehydration, 2 stage high-concentration bleaching, 2 stage dehydration;Pulp after 2 stage dehydration is latent, refining etc., and the finished product is prepared.This application process can produce high-strength, high-cleanliness chemical pulp, and the pulp cost is lower, and the pulp quality is better, and it is beneficial to high-end cultural paper etc. application.

This application provides a method for applying a plant-extracted bioenzyme to paper pulp treatment. Specifically, it involves applying plant-extracted peroxidase to the pre-bleaching delignification treatment of mechanical pulps from bamboo, reeds, and eucalyptus using H2O2. Key parameters in the treatment process, such as enzyme dosage, treatment time, and H2O2 addition, are optimized. The optimal treatment scheme is determined by measuring the total lignin and surface lignin content and fiber morphology of the treated samples. This optimal scheme is more effective in improving the fiber strength and brightness of the treated pulp compared to conventional enzyme treatment methods. Furthermore, molecular docking simulations are performed using a model of the plant-extracted peroxidase and lignin model compounds (LMCs) with different degrees of polymerization to obtain information on the interaction between the enzyme and LMCs, revealing the mechanism of action between peroxidase and lignin. This provides reliable evidence and technical reference for the feasibility of using plant-extracted peroxidase to remove surface lignin from mechanical pulp and promote subsequent H2O2 bleaching.

The invention discloses a manufacturing method of an environment-friendly paper product. The environment-friendly paper product is prepared from the following raw materials in parts by mass: 60-70 parts of a main fiber raw material, 25-35 parts of an auxiliary fiber raw material, 3-8 parts of an environment-friendly additive and 1-2 parts of a pretreating agent. By means of the components, by adding the auxiliary fiber raw materials, the environmental protection property is remarkably improved, waste cotton and linen and agricultural waste are converted into papermaking raw materials, consumption of primary fibers is reduced, meanwhile, waste recycling is achieved, and pollution caused by incineration and landfill is reduced. The auxiliary fibers and the main fibers have a synergistic effect and are matched with the environment-friendly auxiliaries to reinforce the quality of the paper, the cotton and linen fibers improve the flexibility, the agricultural waste fibers enhance the stiffness, lignin and short fibers are separated through low-temperature pyrolysis, impurities are prevented from affecting the performance of the paper, and solid powder rich in the lignin and the short fibers is recycled and reused.

The invention discloses a chlorine-free environment-friendly bleaching agent for refined cotton. Comprising the following raw materials in parts by weight: 5-18 parts of peracetic acid, 10-30 parts of hydrogen peroxide, 5-8 parts of a sodium alginate / PEG4000 / modified cellulose nanowhisker compound, 1-5 parts of an organic acid catalyst, 0.05-0.5 part of a dipicolinic acid stabilizer, 0.01-0.1 part of a magnesium salt stabilizer, 2-10 parts of a pH buffer solution and 40-60 parts of deionized water. According to the chlorine-free environment-friendly refined cotton bleaching agent disclosed by the invention, efficient bleaching under mild conditions is realized through precise matching of a composite oxidation system and a multi-element synergistic protection system; meanwhile, the invention provides a preparation method and an application process of the bleaching agent, the bleaching agent is adaptive to the existing production line, and enterprise upgrading cost is reduced.

There is provided a bleached high temperature chemithermomechanical pulp and a method for producing said HT-CTMP comprising the steps: a) providing wood chips comprising softwood, hardwood or mixtures thereof; b) impregnating the wood chips with an impregnation liquid comprising NaOH and / or Na2SO3 to obtain impregnated chips; c) transferring the impregnated chips to a heating zone without compressing the impregnated chips; d) heating the impregnated chips in the heating zone with steam having a temperature of above 140 °C, such as at least 150 °C, such as at least 160 °C, to obtain pre-treated chips; e) defibrating the pre-treated chips to obtain a pulp; f) bleaching the pulp to obtain a bleached pulp; and g) refining the bleached pulp at a consistency of 3-8 wt. % to obtain bleached HT-CTMP.

A variant polypeptide of xylanase, and a fusion protein and an enzyme composition comprising the variant polypeptide, a recombinant host cell for production of the variant polypeptide, methods for using it and its use, is disclosed comprising an amino acid sequence having at least 79%, but less than 100% amino acid sequence identity with amino acids 1-191 of SEQ ID NO: 1, wherein the amino acid sequence has xylanase activity, at least one disulfide bridge between two Cys residues in the 1-191 amino acid region, and an amino acid substitution at the position 23 or 28, or at the positions 23 and 28, the positions corresponding to the positions 23 and 28 of the SEQ ID NO: 1.

The invention provides bamboo reed bleached fluff pulp as well as a preparation method and application thereof, and belongs to the field of papermaking. According to the characteristics of low bonding strength and small bursting strength of the arundo donax short fibers and parenchyma cells, the use of chemicals such as a debonding agent and the like is canceled, the preparation process is different from a traditional bamboo fluff pulp preparation process, the components of the arundo donax short fibers are reserved, the three-dimensional structure of the arundo donax bleached fluff pulp fibers is optimized, the water absorption and water retention capacity of the fluff pulp is improved, and meanwhile, the paper pulp yield is optimized. According to the raw material characteristics of the bamboo reed, the process conditions of prehydrolysis, cooking and bleaching are optimized, and an economical and efficient bleached fluff pulp product of the bamboo reed pulp is produced, so that the method has good practical application value.

The present disclosure relates to a method for producing chemithermomechanical pulp, CTMP, comprising: a) providing wood chips comprising softwood, hardwood or a mixture thereof; b) storing the chips at a temperature of 45-75 °C for at least 24 h in an aerobic environment to obtain matured chips; c) impregnating the matured chips with an impregnation liquid to obtain impregnated chips; d) transferring the impregnated chips to a heating zone; e) heating the impregnated chips in the heating zone with steam to obtain pre-treated chips; f) defibrating the pre-treated chips to obtain a pulp; and g) dewatering the pulp.

The invention relates to an impurity removal method of a chlorine dioxide vertical generator, which comprises the following steps: adding first pure water and a sodium hypochlorite solution into the chlorine dioxide vertical generator, continuously boiling under a vacuum condition, cooling and discharging liquid; washing with second pure water and discharging liquid; the boiling temperature is lower than 80 DEG C. Different from the prior art, the technical scheme provides a mode for efficiently removing impurities in a mode that the sodium hypochlorite solution is boiled at the temperature lower than 80 DEG C, the boiling temperature in the mode is lower than the efficient decomposition temperature 80 DEG C of hypochlorite, the hypochlorite is high in stability, the decomposition amount is small although the hypochlorite is boiled, and therefore the impurity removing efficiency is higher; the chlorine dioxide vertical generator impurity removal device has the advantages of simple and effective impurity removal of the chlorine dioxide vertical generator, no residue, reduction of the decomposition of chlorine dioxide, and improvement of the production efficiency and the production safety.

An article including a first fiber derived from a first natural source and a second fiber derived from a fruit. A method of manufacturing an article may include combining a first and second fiber to form a fiber mixture, where the first and second fibers are obtained from discrete materials, and where at least one of the fibers is derived from an edible fruit of a plant. The article may be formed from the fiber mixture.

The present application relates to the field of genetic engineering and protein modification technology, and particularly relates to a novel basic xylanase mutant. The present application is based on wild-type xylanase H1, and provides a mutant containing at least one mutation site of Q24P, S38V / K / W / H / T / I, G40M / R / K / F / H, D41P, N56L / I / P / K, A57E / D / Y, A59K / R / I / M / H, H61F / Y, A75S, T80M, T103I, T107E, T114Y, D129L, Q132R / M, D135M, N143D, K144R, T149L, Q151N / Y, C154N, D157E, A160E, N165D, V166I, N167S / W, T177V, D192E. The tolerance of the mutant to high temperature and alkaline environment is significantly improved, which is beneficial to its wide application in the field of papermaking.

The invention provides a composite metal catalyst and application thereof in biological combined light treatment paper pulp bleaching. The method comprises the following steps: dividing and brooming cooked paper pulp fibers by adopting biological pretreatment, and then carrying out illumination bleaching under simulated sunlight irradiation by adopting a metal photocatalyst (ZnO, ZFO, ZAO, ZMO and the like). According to the mild treatment method, the whiteness of the paper pulp is improved, and meanwhile it is guaranteed that fibers are not damaged. Compared with traditional chemical bleaching, biological combined light treatment bleaching has the advantages that the content of pollutants in wastewater is greatly reduced, meanwhile, reacted metal oxides can be recycled, and the combined treatment method can be used as a novel paper pulp fiber bleaching mode.

A system for decolorization of material comprising cellulose including: a purification stage for removing non-cellulosic components from cellulose in alkaline process conditions; a first decolorization stage for decolorizing the material comprising cellulose in alkaline process conditions; and a second decolorization stage for decolorizing the cellulose in alkaline process conditions; wherein the first and second decolorization stages use ozone and hydrogen peroxide; wherein the purification stage and the second decolorization stage include washing the cellulose, wherein the purification stage, the first decolorization stage and the second decolorization stage are connected to the subsequent stage by a process line for feeding the cellulose; and wherein each washing arrangement is connected to the washing arrangement of a preceding stage by a filtrate line for feeding wash filtrate of the washer of a preceding stage.

The application belongs to the technical field of bioengineering, and particularly relates to a high-temperature-resistant laccase mutant obtained by site-directed mutation through an overlapping PCR technique, and preparation and application thereof. The laccase mutant is obtained on the basis of a wild-type laccase shown in SEQ ID NO. 1, and at least one of D221Y, E231D, Y441H or Y441F mutations occurs, and the mutant enzyme activity and the thermal stability at 80 DEG C are both improved to different degrees relative to the wild type, which is beneficial to expand the application in the industrial fields of degrading lignocellulose, paper pulp bleaching and the like.

The present invention relates to a system for treating delignified cellulose pulp, comprising: consecutive first and second washing devices configured to receive and wash delignified cellulose pulp; an acidic bleaching device arranged to receive cellulose pulp from the second washing device; the post-acid-bleaching washing device is connected to the acid bleaching device and is used for washing the cellulose pulp received from the acid bleaching device; an alkaline bleaching device arranged downstream of the washing device; the alkaline bleaching post-washing device is connected to the alkaline bleaching device and is used for washing the cellulose pulp received from the alkaline bleaching device; a filtrate feeding means arranged to recycle the waste washing liquid from the post-alkaline-bleaching washing means as a diluent between the first washing means and the second washing means and / or as a washing liquid to the first washing means; and a source of water and / or condensate connected to the second washing device to provide a washing liquid.

Disclosed are improved non-woody slurries, in particular non-woody slurries prepared from plants of the family Aspartate, and more particularly one or more plants of the genus Yucca, and methods of making the same. The method of manufacture generally includes at least one mechanical processing stage, such as mechanical refinement, without adding chemicals to the biomass. In some cases, the biomass may be subjected to two stages of refinement where the consistency of the biomass differs between the stages such that the first refinement stage may be performed at a consistency in the range of about 8% to about 12% and the second stage may be performed at a consistency in the range of about 3% to about 4%. The resulting non-wood slurry has a high degree of freeness, such as freeness in the range of 500 mL to 600 mL, and a relatively moderate degree of tensile strength, such as a tensile index of about 50 or less.

The invention belongs to the field of gene engineering and enzyme engineering, and particularly relates to mannase derived from space mutagenesis yeast strains as well as a preparation method, a product and application of the mannase. The amino acid sequence of the mannase is as shown in SEQ ID NO.2, and the nucleotide sequence of the mannase is as shown in SEQ ID NO.3. The mutant retains 70% of enzyme activity at a high temperature (85 DEG C for 3 min, and only 40% of original enzyme remains at 85 DEG C for 3 min) and has an acid pH value (the stability is improved from 3% to 25% after treatment for 180 min at pH 3.0), and meanwhile, the mutant has the low-temperature efficient catalytic characteristics that the optimum pH value is 7.0, the optimum temperature is 40 DEG C, and 30% of enzyme activity is kept at 20 DEG C, and has remarkable application potential in the fields of feed, paper-making industry and the like.

The utility model relates to the technical field of paper pulp bleaching, and discloses a hydrogen peroxide supply device for a wood pulp bleaching process, which comprises an oxygen generator, a water purifier, a liquid caustic soda pressure stabilizing and filtering system, a hydrogen peroxide electrolysis production system, an energy storage system and the like. And an alkaline hydrogen peroxide storage tank is arranged on the outer side of the hydrogen peroxide electrolysis production system. According to the hydrogen peroxide supply device for the wood pulp bleaching process, in order to better control the flow of alkaline hydrogen peroxide, high-purity oxygen is stably supplied through the oxygen generator, and the liquid caustic soda pressure is stabilized and impurities are filtered through the liquid caustic soda pressure stabilizing and filtering device, so that the stable quality of the generated alkaline hydrogen peroxide is ensured; the alkaline hydrogen peroxide outlet flow meter and the alkaline hydrogen peroxide discharging pump work cooperatively, the flow of the alkaline hydrogen peroxide can be accurately controlled according to actual requirements, accurate supply is achieved, and the problem that the bleaching effect is unstable due to fluctuation of the dosage of the hydrogen peroxide is solved.

The present disclosure relates to a modified polypeptide having xylanase activity and the use thereof.

The invention discloses a continuous efficient decolorizing and bleaching system and process for preparing recycled pulp from waste textiles, and belongs to the technical field of waste textile recycling. The decolorizing and bleaching machine with a sectional type screw rod structure, process unit integration and the like is adopted for carrying out pretreatment, decolorizing treatment, first cleaning treatment, bleaching treatment and second cleaning treatment, so that continuous and efficient decolorizing, bleaching and cleaning on the waste textiles (especially the waste textiles containing indigo dyes) under the condition of medium and high concentration (10-30%) are realized; consumption of chemical agents and water resources is reduced, the technological process is shortened, and the technological requirements are met.

The invention provides a paper product, chemimechanical pulp and a preparation method of the chemimechanical pulp. The preparation method comprises the following steps: taking high-concentration grinding spraying pulp in a first concentration range; diluting the pulp to a second concentration range by using bleaching filtrate or clear water; dehydrating the slurry to a third concentration range; wherein the first concentration range and the third concentration range are both larger than the second concentration range; and adding a bleaching medicine into the pulp. According to the preparation method of the chemimechanical pulp for papermaking provided by the embodiment of the invention, the cleanliness of the pulp entering a bleaching tower is improved, the consumption of bleaching drugs is reduced, and the whiteness of the paper pulp is improved by adding a high-concentration mill pulp washing process.

The application discloses a kind of high thickness of high bulk pulp and its preparation process, belong to papermaking technical field.The technical scheme is as follows: including the following steps, raw material preparation and pre-soaking treatment, reaction bin reaction, high consistency refining treatment, bleaching, latent elimination, low consistency refining, screening and washing, 1) raw material preparation and pre-soaking treatment: the raw material wood chip is broken, then pre-soaking is carried out, control pre-soaking temperature 80~90 ℃, pH value 9.8~10.2, liquid level ≥50%, ADI back pressure ≥4bar, NaOH dosage is 1.5%~2.0% of dry wood chip weight;2) high consistency refining treatment: the wood chip after pre-soaking is sent into high consistency refiner for refining, refining consistency 35~45%;3) bleaching: pulp after refining is sequentially subjected to one-stage bleaching and two-stage bleaching.The application process has high stability, and can realize the synchronous and stable improvement of bulk and freeness.

The invention provides a bamboo pulp corrugated carton preparation technology, and relates to the technical field of corrugated carton preparation, the bamboo pulp corrugated carton preparation technology comprises the following steps: S1, bamboo pulp paper preparation: S11, pulping, S12, paper pulp blending, and S13, papermaking; s2, corrugated board preparation: pressing the wood pulp paper into core paper by adopting a single-sided machine, coating an adhesive on a corrugated peak part on one side of the core paper by adopting the single-sided machine, so that the core paper and the inner paper are initially adhered to form a single-sided corrugated board, coating an adhesive on a corrugated peak part on the other side of the core paper by adopting a double-sided machine, and adhering the single-sided corrugated board and the surface paper to form double-sided corrugated paper; and S3, corrugated case preparation: forming lap joint grooves in the double-sided corrugated paper prepared in the S2 by adopting a grooving machine, pressing folding lines, and performing die cutting forming by adopting a die cutting machine to prepare the corrugated case. Bamboo pulp is used as surface paper and inner paper, the cost advantage is remarkable, the problems of moisture absorption and embrittlement of a corrugated carton are solved, and the performance defects caused by bamboo pulp fiber short boards are overcome.

The invention belongs to the technical field of pulping, and particularly relates to a method for preparing dissolving pulp by using herb gold violet as a raw material. The preparation method comprises the following steps: crushing, screening, washing and filtering grass gold violet serving as a biomass raw material, entering a transfer bin, putting the grass gold violet into a reaction kettle, carrying out steam explosion twice and alkali liquor reaction, and after the reaction is finished, squeezing, pulping, bleaching, secondary squeezing, forming and drying to obtain the finished product dissolving pulp. The preparation method disclosed by the invention is high in environmental protection property, high in pulping yield and excellent in pulp quality, and provides a new direction for industrial pulping.

The invention belongs to the field of macromolecules, and discloses a preparation method of poly-alpha-hydroxy acrylic acid, which comprises the following steps: step 1, adding water, alpha-chloroacrylic acid and an oxidant into a reaction container in an inert atmosphere, and keeping the temperature at 20-40 DEG C; 2, alpha-chloroacrylic acid and a reducing agent are added into the reaction container in a dropwise adding mode within 30-60 min, and stirring is assisted; 3, after dropwise adding is completed, a constant-temperature reaction is conducted for 30-60 min, then the temperature is increased to 80-90 DEG C, a peroxidation initiator is added to eliminate alpha-chloroacrylic acid which is not completely reacted, and the constant temperature is kept at 80-90 DEG C for 1-2 h; 4, filtering after the reaction is stopped, and collecting a polymer solid; and step 5, adding the polymer solid into alkali liquor, and fully hydrolyzing to obtain the poly-alpha-hydroxy acrylic acid. The poly-alpha-hydroxy acrylic acid is moderate in molecular weight and narrow in molecular weight distribution, serious intermolecular lactonization is not prone to being formed in the production process, and the gelation phenomenon can be remarkably delayed and relieved. Meanwhile, the invention also discloses application of the polymer.

The invention relates to the field of pulping and papermaking, in particular to a mediator-free laccase delignification bamboo pulp bleaching method which comprises the following steps: S1, mixing laccase and absolute dry pulp, adjusting pulp concentration, introducing oxygen at a certain temperature for reaction, washing with deionized water, spin-drying and scattering; the absolutely dry pulp is obtained by defibering, screening and drying unbleached chemical bamboo pulp. And S2, carrying out acid pickling chelation on the absolutely dry slurry treated in the step S1. And S3, bleaching the absolutely dry slurry treated in the step S2. According to the method, the lignin in the bamboo pulp is efficiently removed, the kappa number is reduced by more than 40%, the biological enzyme is directly used for replacing about 30% of total chemicals under the condition of not changing the section of an oxygen removal tower in the original process, and the consumption of chemicals and the discharge of bleaching wastewater in industrial production are reduced; and meanwhile, no expensive mediator is added, so that the problem of corrosion of the mediator to equipment is avoided, and the maintenance cost is greatly reduced.

The invention discloses a preparation method of acetified pulp, which comprises the following steps: firstly, pretreating a plant fiber raw material by using organic acid to destroy a lignin structure and dissolve out hemicellulose; then carrying out sulfate cooking, controlling the alkali consumption and the sulfuration degree, and completing purification of the cellulose at a preset temperature; further removing residual impurities through an alkali refining process; and finally, performing ECF bleaching and drying to obtain finished pulp. Through efficient cooperation of the three-stage process, the alpha-cellulose content, whiteness and reaction activity of the pulp are remarkably improved, meanwhile, the method has the advantages of being high in organic acid recovery rate, capable of recycling alkali liquor, low in wastewater treatment cost, wide in applicable raw material range and the like, and production can be achieved by simply modifying the sulfate pulp process.