35 results about "Kraft process" patented technology

The invention discloses a preparation method of baking paper, and relates to the technical field of papermaking industry. According to the invention, the acidic bisulfite softwood pulp is used as a raw material, and the paper is endowed with an oil-proof characteristic through high-beating treatment, so that not only can potential harm to a human body caused by the use of an oil-proof agent in the baking paper be avoided, but also the problem of high energy consumption caused by high-beating-degree papermaking of the softwood pulp by a sulfate method in the prior art is solved.

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 efficiently preparing high-catalytic-performance biochar based on pulping black liquor and application. The invention belongs to the field of waste biomass high-value conversion and application. The method aims at solving the technical problem that efficient recovery of lignin in the sulfate pulping black liquor and conversion of biochar with excellent functionality cannot be synchronously achieved through an existing method. The method comprises the following steps: placing the waste biomass in a mixed solution of sodium hydroxide and sodium sulfide, and heating at high temperature to obtain black liquor; adding ferric chloride hexahydrate into the black liquor, carrying out heating reaction, centrifuging and drying, and then carrying out high-temperature pyrolysis in a tubular furnace; according to the method disclosed by the invention, preparation of a high-value product after separation and recovery of the lignin is taken as a target guide, corresponding means are adopted to precipitate the lignin and endow the lignin with conversion potential, the sulfur element in the black liquor is fully utilized, meanwhile, other metal elements are introduced, and the biochar with excellent functionality is obtained by further optimizing process parameters. The obtained biochar is used for catalyzing peroxymonosulfate to degrade antibiotic wastewater.

The APPARATUSES, METHODS AND SYSTEMS FOR APPARATUSES, METHODS AND SYSTEMS FOR YIELD INCREASE IN A KRAFT COOKING PLANT present synergies for at least two parallel cooking plants, e.g., one producing dissolving pulp in a prehydrolysis kraft process, and the other producing kraft pulp by kraft pulping process, which may facilitate increased cooking yield in the kraft cooking plant producing kraft pulp by recovering the hemicelluloses solubilized in the acidic hydrolysate of the prehydrolysis kraft process. In some implementations, there may be no cold caustic extraction step on the dissolving pulp line as the target pulp purity can be achieved by performing just a prehydrolysis step, with reutilization of an acidic hydrolysate stream in a kraft pulp line.

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 provides a method for predicting the calorific value of broadleaf wood sulfate pulping black liquor, which is characterized in that the black liquor condition of production operation caused by a raw material structure to be put into use is predicted according to a prediction equation, the prediction equation is y (QN) = 0.6725 x (QS)-121.41, and the fitting degree R2 = 0.9394. The error between the predicted value and the measured value of the calorific value of the broadleaf wood sulfate pulping black liquor obtained according to the prediction equation is less than 10%, which indicates that the prediction equation is high in accuracy. According to the prediction equation in the prediction method, the recovery heat value of the sulfate pulping black liquor taking different broadleaf wood species as raw materials is predicted, so that the raw material ratio is reasonably and effectively used in the industrial production process, an alkali recovery system is stabilized, and production operation is stabilized. The prediction method is small in error, high in accuracy and good in application prospect.

According to an example aspect of the present invention, there is provided a method of replacing with sodium make-up chemicals sodium losses caused by outflows in a pulp mill which employs a kraft process for producing cellulosic pulp, wherein the pulp mill includes a unit for conversion of sulphurous compounds, which is fed with sulphurous substances of the kraft process to convert said sulphurous substances into oxidized sulphurous compounds, said method comprising using sodium sulphate possibly together with other sodium salts as the main make-up chemical, to achieve an essentially sodium hydroxide free feed of sodium make-up chemicals, and at least a part of the sulphur contained in the sodium sulphate make-up chemical being used for producing oxidized sulphurous compounds in said unit for conversion of sulphurous compounds.

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 invention discloses high-water-resistance packaging kraft base paper and a papermaking method thereof. The method comprises the step that high-kappa-number hardwood pulp and recycled waste paper fibers which are prepared through a sulfate method are adopted for a surface layer and a bottom layer. After the slurry is ground, a water repellent agent is added, and a large-sizing-amount sizing metering rod is replaced, so that the treatment effect is improved. Through the method, the high-water-resistance packaging raw paper which is difficult to permeate when encountering water is produced. Under the condition that existing conditions are not changed greatly, the paper developed through the method has high water resistance, is suitable for manufacturing packaging boxes in packaging scenes of cold chain packaging, beverages and the like, meets the requirements of customers and improves the benefits of companies.

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.