29 results about "Kraft process" patented technology

The invention discloses a preparation method of a nitrogen-sulfur co-doped lignin-based hierarchical porous carbon material and supercapacitor energy storage application, and belongs to the technical field of preparation methods and application of porous carbon materials, and the preparation method comprises the following steps: (1) dropwise adding an ammonium sulfate solution into sulfate pulping black liquor, and adjusting the pH value, after standing reaction, drying to obtain ammonium sulfate precipitated lignin; (2) uniformly mixing lignin with potassium tartrate and potassium nitrate, drying and grinding to obtain a mixture; and (3) pyrolyzing the mixture in an inert atmosphere, washing the carbonized product with dilute acid, filtering, and drying to obtain the porous carbon material. Potassium tartrate promotes formation of graded pores through the mild pore-forming effect, and the foaming effect of potassium nitrate can inhibit formation of coal tar and excessive carbon skeleton etching in the pyrolysis process. The supercapacitor electrode material prepared from the porous carbon has high specific capacitance, excellent cycling stability and high energy density.

A digester additive formulation includes a combination of phenyl tetracarboxylic acid or a derivative or salt thereof, and a macromolecule polymer. The digester additive formulation is as an additive for a kraft process for production of pulp from raw materials, such as wood chips. When used in the kraft pulping process, the digester additive formulation improves viscosity of the resulting pulp and increases pulp yield.

The invention discloses a high-strength environment-friendly craft paper production process with low bleached hardwood pulp consumption, and relates to the technical field of papermaking, and the high-strength environment-friendly craft paper production process comprises the following steps: adopting 20-30% by mass of natural-color sulfate-process softwood pulp and 70-80% by mass of recycled paper pulp; pulping the natural-color sulfate-process softwood pulp by using three conical pulping machines which are connected in series; grading and screening the recycled paper pulp into long, medium and short fibers for later use; carrying out heat dispersion treatment on the recycled paper pulp subjected to the grading treatment by utilizing a heat dispersion machine; adding a mucilage control enzyme into the recycled paper pulp subjected to heat dispersion treatment; blending slurry; surfing the Internet; squeezing the paper; sizing on the surface; and hard calendaring. According to the method, the high-strength environment-friendly craft paper with the burst index of 2.8 kPa.m < 2 > / g can be produced on the premise that the pulp consumption of the natural color needle leaf pulp is low; the prepared high-strength environment-friendly craft paper has the advantages of low cost and low market demand.

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.

A method for making a hemicaustic superabsorbent polymer from a hemicaustic byproduct, such as a kraft (sulfate), prehydrolized kraft or sulfite pulping process hemicaustic byproduct. The hemicaustic byproduct can be extracted from a pulp slurry as a hemicaustic suspension by treating the cellulosic pulp slurry with a cold caustic solution, then isolating the hemicaustic suspension and grafting a polar water-soluble vinyl monomer on hemicelluloses present in the hemicaustic suspension to produce a hemicaustic based superabsorbent polymer.

The present invention is directed to fractionation of crude tall oil, which originates from the Kraft process black liquor. In the method according to the present invention, at least two strongly basic anion exchange resins are used to efficiently separate fractions from the crude tall oil.

The invention discloses a method for extracting lignin from sulfate pulping black liquor, which comprises the following steps: heating the black liquor to 50-70 DEG C in the stirring process, then adjusting the pH value of the black liquor to 3.0-4.5 by using organic acid, stopping adding acid, and aging under the conditions of stirring and 50-70 DEG C to obtain aged pulp; centrifuging the aged slurry, discarding the supernatant, collecting the precipitate, then washing the precipitate with acidic water, repeating the steps of centrifuging and washing for several times, and collecting the precipitate to obtain a crude lignin filter cake; and treating the obtained crude lignin filter cake in a phosphoric acid solution, washing the obtained product until the pH value of the filtrate is neutral, and then drying to constant weight to obtain the phosphorylated lignin. According to the invention, low vulcanization, high purity and functionalization (high thermal stability) of the product can be realized at the same time, so that the application barrier of the existing lignin is broken, and the huge potential of the lignin as a renewable resource is released.

The present application belongs to the field of comprehensive utilization of lignocellulosic biomass raw materials, and provides a method for comprehensive utilization of chemical mechanical method / sulfate method pulping waste liquid. First, the lignin-carbohydrate complex (LCC) degradation is obtained by using sulfuric acid acidification pulping black liquor and catalysis, and then the hemicellulose in the black liquor is converted into furfural and acetic acid by using sulfuric acid acidolysis and catalysis. The whole process fully utilizes the different chemical properties of sulfuric acid at different temperatures, realizes the different effects of sulfuric acid on the main components in the pulping black liquor by adjusting the treatment temperature, and extracts or prepares lignin, furfural and acetic acid, realizing the high-value utilization of black liquor.

The application discloses a method for preparing electronic-grade insulating pulp from bamboo, and relates to the technical field of insulating pulp production and preparation, and comprises the following preparation steps: step A, collecting bamboo raw materials in Hunan area; step B, flaking operation, bamboo is flaked and cut into pieces in a bamboo processing factory; step C, water washing operation, bamboo pieces are washed to balance water content; step D, cooking operation, bamboo pieces are cooked by adopting sulfite process, and the yield of the crude pulp is controlled to be 40-50%; step E, screening operation; step F, beating operation; step G, sheeting operation and strength detection. The method for preparing electronic-grade insulating pulp from bamboo has certain regionalism by adopting locally planted bamboo in Hunan, the prepared electronic-grade insulating pulp reaches the superior standard, and the prepared electronic-grade insulating pulp has the quality index that the conductivity is less than 3 us / cm by adopting deionized water for washing in the whole process.

The present invention relates to the fractionation of crude tall oil derived from sulfate process black liquor. In the process according to the invention, fractions are effectively separated from crude tall oil using at least two (two) strongly basic anion exchange resins.

The invention discloses a method for preparing dissolving pulp, which comprises the following steps: 1) adding eucalyptus into an ultralow acid-phenoxyethanol two-phase solvent system for two-phase pretreatment, and filtering to remove filtrate to obtain a solid material; (2) adding the solid material into a NaOH-Na2S solution, and cooking by a sulfate process to obtain sulfate pulp; and 3) performing ECF bleaching on the sulfate pulp to obtain the dissolving pulp. The method for preparing the dissolving pulp has the advantages of being good in raw material compatibility, high in cellulose retention rate, high in lignin and hemicellulose removal rate, small in medicine dosage and the like, and the prepared dissolving pulp is high in quality and suitable for large-scale industrial application.

The invention discloses a sample preparation method and a sample preparation system for flash drying pulp, and belongs to the related technical field of manufacturing of drying pulp, the method comprises the following steps: S1, using sulfate-process bleached softwood pulp as a raw material; s2, dissolving the pulp board through a hydrapulper or defibering the pulp board through a pulp defibering machine; s3, the defibered pulp is spin-dried through a centrifugal dehydrator, and the dryness of the pulp is improved to 32%; s4, treating the spin-dried pulp by a spiral pulper; s5, the dryness of the treated slurry is increased to 50% through a chain dryer so as to adapt to flash drying raising equipment; and S6, feeding the wastewater of the centrifugal dehydrator and the subpackaged mesh bag into a wastewater filter for reuse. The method is used for solving the technical problems of high production cost and unstable product quality caused by the fact that the preparation of the flash drying pulp generally depends on imported high-cost raw materials and the preparation process is complicated and low in efficiency in the prior art.

The present invention relates to a method for producing a delignified and densified wood product. The wood is delignified in the form of a veneer using process conditions corresponding to the sulfate process. The wood veneer is subjected to a pre-hydrolysis treatment prior to a process step corresponding to the sulfate process. The invention also relates to a delignified and densified wood product produced using said method. The delignified and densified wood product according to the invention has particularly advantageous strength properties.

The invention provides a method for promoting the enzymatic hydrolysis efficiency of lignocellulose. The method comprises the following steps: (1) firstly, respectively preparing biomass primary pulp of a lignocellulose raw material by using a sulfate method; (2) holocellulose is prepared from the biomass primary pulp through a bleaching method, the bleaching time is 15-20 min, and the content of combined lignin in the holocellulose is 5% or below; (3) carrying out enzyme hydrolysis on holocellulose of which the content of bound lignin is less than 5% to obtain hydrolysate; the cellulose conversion rate of the hydrolysate is 90% or more. The method is low in cost and simple in preparation, the removal time of lignin in a reaction substrate is shortened, invalid adsorption of lignin to cellulase can be effectively reduced, catalytic hydrolysis of lignocellulase is promoted, and the conversion rate of cellulose is increased to 96.95%.

The present invention relates to a method for reducing metal content in a kraft pulping process, which includes adding magnesium to black liquor that is returned to the pulping operation; a method for reducing aluminum content in a pulping process by adding magnesium to black liquor to provide green liquor with a specific magnesium:aluminum molar ratio; a method for producing or treating green liquor with a specific magnesium:aluminum molar ratio by adding magnesium to black liquor, weak black liquor, or strong black liquor; and a method for producing hydrotalcite by adding at least 0.04 to 5.0 moles of magnesium:aluminum present in weak black liquor, strong black liquor, or a combination thereof. A pulp mill is also provided, which includes, among other parts, a digester (1), a washer (2), optionally a pulp bleacher, and a weak black liquor thickener (4).

In a modified sulphate process for making titanium dioxide, based on an acid attack of a titanium-containing mineral such as Ilmenite and / or titaniferous slags, a method for treating an acidic liquid waste (6,6a) of a titanium dioxide production process via sulphate includes two concentration stages (S10,S20) comprising respective steps of bubbling (S11,S21) a first and a second gas (11,22) into the acidic liquid waste (6,6a,16,16a), carried out in a first reactor (41,61) at respective first and second process temperatures of at least 90°C and 150°C, respectively, the second gas containing, in particular, carbon dioxide, so as to retain obtain solid metal sulphates (23) in the first reactor (61) and a gaseous stream (24) in which sulphur trioxide SO3 and vapours of H2SO4 are present, together with water and carbon dioxide, a selective adsorption phase (S22) of SO3 / H2SO4 into a water solution (26) progressively concentrating in a second reactor (91) connected to first reactor (61) via a feed duct (92) arranged to convey gas form the first to the second rector (61,91), up to a predetermined concentration, forming a concentrated sulphuric acid (28), in which a residual gaseous stream (27) after absorption can be further fractionated to recycle the carbon dioxide into the carbon dioxide-containing gas stream (22) fed to the effluent mass, while the solid metal sulphates are recovered once the acidic liquid waste mass is exhausted. A filtration step (S12) can further be provided of filtering the partially concentrated liquid acidic waste coming from first concentration stage so as to cause the solid metal sulphates (13) settled during the first bubbling step, mainly including Ferrous sulphate to be separated.

The present invention provides a biobased and biodegradable cooking enhancement formulation for kraft pulping and a process for preparing the same. The formulation comprises lauryl alcohol ethoxylate, alpha olefin sulphonate, polysorbate-20, lactic acid, and water as essential components. The synergistic combination of these ingredients enhances delignification efficiency in kraft cooking by improving liquor impregnation, promoting oxidation through in situ peracid generation, and stabilizing oxidized lignin fragments through emulsification. The formulation enables efficient delignification at reduced active alkali concentration and lower cooking severity, thereby improving pulp brightness and yield while reducing rejects and pitch content. The biobased composition provides a non-toxic and environmentally safe alternative to conventional anthraquinone-based cooking aids and is completely biodegradable. The invention thus offers an effective and sustainable solution for improving kraft pulping performance and process efficiency.

The present invention discloses a short-process and low-cost continuous and stable gold extraction process by thiosulfate method, belonging to the field of hydrometallurgy. In a closed reactor, by adjusting the concentrations of dissolved O2, thiosulfate and catalyst to a lower level, the pulp potential is decreased to an appropriate range to leach gold ore, and the leached residue and leached pregnant solution are obtained by filtration. Pure nitrogen is introduced into the leached pregnant solution to exhaust the oxygen in the solution, and copper powder is added for displacement. The copper-rich crude copper and the displacement lean solution are obtained by filtration. The copper-rich crude copper is treated by electrolytic refining, pure copper is obtained at the cathode, and gold mud is obtained at the anode. The gold mud is washed with dilute acid to obtain the acid washing solution containing copper and pure gold. After adjusting the pH of the acid washing solution containing copper, it is combined with the displacement lean solution supplemented with the leaching agent for the leaching of fresh ore in the next cycle. The method of the present invention takes into account the problems of long process flow, high cycle cost and great environmental protection pressure of the copper-ammonia-catalyzed thiosulfate method, and is suitable for use in the natural environment.

The invention relates to the field of oil and gas exploitation, in particular to a corrosion inhibitor for carbon dioxide corrosion and a preparation method thereof. The corrosion inhibitor for carbon dioxide corrosion comprises the following components: foots, sodium hydroxide, a paper pulp by-product, sulfuric acid, m-phenylenediamine, rosin amine, diethylenetriamine and EDTMP, and the paper pulp by-product is a by-product obtained by using wood as a raw material and preparing paper pulp through a sulfate method. The corrosion inhibitor for carbon dioxide corrosion not only is low in cost, but also is low in corrosion rate.

A digester additive formulation includes a combination of phenyl tetracarboxylic acid or a derivative or salt thereof, and a macromolecule polymer. The digester additive formulation is as an additive for a kraft process for production of pulp from raw materials, such as wood chips. When used in the kraft pulping process, the digester additive formulation improves viscosity of the resulting pulp and increases pulp yield.

The application relates to a method for efficiently preparing high-catalytic-performance biochar based on pulping black liquor and application. The application belongs to the field of high-value conversion and application of waste biomass. The purpose of the application is to solve the technical problem that the existing method cannot simultaneously realize efficient recovery of lignin in kraft pulping black liquor and conversion of excellent functional biochar. The method of the application is as follows: waste biomass is placed in a mixed solution of sodium hydroxide and sodium sulfide and heated at high temperature to obtain black liquor; iron chloride hexahydrate is added to the black liquor, heated for reaction, centrifuged, dried, and then pyrolyzed at high temperature in a tube furnace. The application takes the preparation of high-value products after lignin separation and recovery as a goal, adopts corresponding means to precipitate lignin and endow the lignin with product conversion potential, fully utilizes the sulfur element existing in the black liquor, simultaneously introduces other metal elements, and further obtains excellent functional biochar by optimizing process parameters. The obtained biochar is used for catalyzing peroxymonosulfate to degrade antibiotic wastewater.

A useful digester aid for a Kraft pulping process is an aromatic polycarboxylic acid that: (a) contains an aromatic moiety having on average at least 2 carboxylic acid groups per molecule pendant from the aromatic moiety; and (b) has an electron affinity below -2.80eV and at least -3.6eV. or is a functional equivalent of the aromatic polycarboxylic acid.

The present invention relates to an ester compound of partially or fully renewable origin, as well as to a process for the preparation thereof involving the esterification of at least one vegetable alcohol with at least one fatty acid derived from the kraft process of pulping wood in the pulp and paper industry in the presence of a catalyst. Furthermore, the present invention also relates to the use of said ester compound in a personal or household care formulation, and to said personal or household care formulation.

This invention belongs to the field of pulping and papermaking technology, and provides a method for constructing a model of component leaching in acacia wood pretreated with microwave-assisted hydrothermal treatment and a method for pulping it. The model was constructed using the component leaching content as a parameter after microwave-assisted hydrothermal pretreatment of acacia wood. The F-value was 161.6355, P < 0.05, reaching a significant level, indicating a very good fit. The R-value of the model is... 2 The value was 0.9728, and the mean square error was 0.0318, indicating a reliable prediction result. The treated acacia wood chips were then subjected to sulfate pulping. The pulp was screened, beaten, defatted, and then processed into paper. The prepared paper exhibited excellent properties, with a tear index of 2.76–7.36 mN·m. 2 / g, tensile index is 44.4-102 N·m / g, burst index is 1.91-6.12 kPa·m 2 The ring compression index is 9.77–14.67 N·m / g. This invention provides a powerful tool for evaluating pretreatment effects and optimizing process parameters, further enhancing the scientific rigor and practicality of the research.

An exemplary embodiment of the present disclosure provides a process for generating new products from a kraft mill and improving operational efficiency of a kraft mill through extraction of bioderived organic acids and liquid CO2 from weak black liquor generated during a kraft process, comprising the steps of: filtering a weak black liquor (BL) stream generated in the kraft process downstream from a brownstock washer to remove a first portion of lignin and generate a reduced lignin or de-lignified permeate and a retentate; removing the reduced lignin or de-lignified permeate from the kraft process; processing at least the de-lignified permeate to generate organic acids, liquid CO2, water, and raffinate containing salts; recovering the organic acids and liquid CO2; and returning the raffinate containing salts to the kraft process downstream of a recovery boiler.

The invention discloses preparation and application of a Fe2O3 anchored porous carbon material, and belongs to the technical field of battery catalysts. The method comprises the following steps: cooking a biomass material by adopting an alkaline sulfite method, filtering and separating to obtain black liquor, adjusting the pH value of the black liquor to 6-8, carrying out centrifugal separation to obtain supernate, mixing the supernate with ferric salt, and sequentially carrying out freeze drying, grinding, carbonization treatment, water washing, suction filtration water washing and drying to obtain a carbon precursor; and mixing the carbon precursor with a nitrogen-containing compound, grinding, and calcining under the protection of an inert atmosphere to obtain the Fe2O3 anchored porous carbon material. The Fe2O3 anchored porous carbon material has the advantages of high specific surface area, hierarchical pore structure, good oxygen reduction activity, high catalytic activity, and good application in the field of catalysis. The method is simple, and the used raw materials are biomass materials which are cheap, easy to obtain and renewable.

A method for separating water and at least one lignin fraction, lignin derivatives, low-molecular carboxylic acids, sodium sulfate, or a mixture thereof from filtrates originating from a black liquor of a kraft process. Black liquor is concentrated to a solids content between 25 and 55 wt. %. A first separation step, polymer lignin with a number average of the molecular mass distribution of >6 kDa is precipitated and filtered out by lowering the pH value of the black liquor, a first filtrate is obtained which is acidified with sulfuric acid; a formed precipitate consisting of lignin is separated by means of filtration; a second acid filtrate is obtained, cooled to a temperature less than 10° C., a fraction consisting substantially of inorganic salts is crystallized out; the formed precipitate is filtered off, a third filtrate is obtained which contains low-molecular carboxylic acid-soluble lignin and groups of the inorganic salts.

The invention relates to the field of sewage treatment, in particular to a treatment method for secondary sedimentation tank float sludge initiated by a DCM control agent in sulfate pulping. The method comprises a step of adding a fusion protein as shown in SEQ ID NO.3 into a secondary sedimentation tank, and further comprises the following steps: regulating the concentration of dissolved oxygen to 2.0-4.0 mg / L, the temperature to 35-40 DEG C and the pH value to 6.8-7.2, hydrolyzing extracellular proteins or extracellular polysaccharides generated by various zoogloea bacteria in the secondary sedimentation tank, destroying a foam skeleton and reducing adhesion of microhyphae, thereby realizing the purpose of removing the microhyphae in the secondary sedimentation tank. And the problem of'combined action of a DCM control agent and filamentous bacteria 'is solved, and the problem of float sludge in a secondary sedimentation tank is solved.

Apparatus, methods, and systems for improving the yield of a kraft cooking facility provide synergistic benefits for at least two parallel cooking facilities. For example, one cooking facility produces dissolving pulp in a prehydrolysis kraft process, while another cooking facility produces kraft pulp via a kraft pulping process. By recovering hemicellulose dissolved in the acidic hydrolyzate of the prehydrolysis kraft process, the cooking yield of the kraft cooking facility producing the kraft pulp can be improved. In some embodiments, a cold caustic extraction step can be eliminated in the dissolving pulp line because only the prehydrolysis step is required to achieve the target pulp purity, and the acidic hydrolyzate stream can be reused in the kraft pulp line.