149results about "Continuous pulping process" patented technology

The present invention serves for loading a pulp suspension (S) with calcium carbonate. Liquid calcium hydroxide as milk of lime (7) is added during or before the pulp operation (1) carried out to form the pulp. By introducing gaseous carbon dioxide (8) into the pulp suspension thus treated, a chemical reaction is triggered therein, in which the finely divided calcium carbonate is precipitated. The present invention is particularly economic and effective due to the early addition of calcium oxide or calcium hydroxide.

The present invention relates to a pulping technology, in particular to a clean pulping technique with straw or broad leaves as raw materials. In the technical scheme, the clean pulping technology mainly includes twelve steps: (1) straw cutting or fragmenting and dedusting; (2) a fly cutter material-washing pool; (3) a raw material bin; (4) a press master; (5) the first-stage high-consistency grinding; (6) a reaction bin; (7) a press master; (8) the second-stage high-consistency grinding; (9) a high-consistency bleaching and temperature-keeping bin; (10) pulping; (11) filtering; (12) washing and whiteness enhancement. The technology uses straw or broad leaves as raw materials to realize the pollution-free fiber pulping technique, and applicable to large and medium paper-making enterprises, the whole pulping technique has the advantages of simplicity, low production cost, high yield rate of white pulp, good pulp quality, obvious reduction of energy consumption, etc.

The present invention relates to the technological scheme of treating bamboo fiber. The treating process of bamboo fiber includes the following steps: pre-treating via cutting bamboo, scraping out green skin and rolling; soaking the pre-treated bamboo in pre-treatment pond with Ca(OH)2 solution of 5-10 wt% concentration for 10-30 days to obtain coarse bamboo fiber; and flushing in the flushing pond to eliminate impurity and obtain pure bamboo fiber. The present invention features that additive mixture comprising NaOH, Na2CO3 and NaHCO3 is added into pre-treatment pond. The present invention has the advantages of less investment, low cost, fast effect, cheap processing solution of Ca(OH)2 and small amount of additive, short processing period and raised mechanical performance of bamboo fiber.

Hardwood pulp rejects at a given Kappa number can be reduced by subjecting the hardwood pulp to specified cooking conditions at the end of cooking. In this regard, it has been discovered that s-lignin reacts faster than g-lignin and that there exists a higher proportion of g-lignin at the end of a hardwood cook as compared to the g-lignin present at the beginning of the cook. Thus, when cooking hardwoods, relatively harsher cooking conditions (e.g., higher cooking temperatures) at the end of the cooking have been discovered to decrease the g-lignin content which in turn decreases the percentage of pulp rejects at a given Kappa number. In preferred embodiments, methods and systems are provided for continuously producing chemical cellulose pulp from a slurry of comminuted hardwood material by subjecting the slurry of comminuted hardwood material to a first cooking stage under conditions sufficient to reduce syringyl lignin (s-lignin) content in the hardwood material as compared to guaiacyl lignin (g-lignin) content therein, and thereafter subjecting the slurry of comminuted hardwood material to a second cooking stage under conditions sufficient to reduce the g-lignin content remaining therein after the first cooking stage.

The invention provides a displacement and continuous cooking method for non-wood fiber and device thereof. The method combines the displacement cooking technology with the transverse tube continuous cooking technology, can improve the pulp quality, hardness and bleaching property, and the black liquor can be recycled. Especially, the method has low energy consumption, protects the environment.

A method for the continuous cooking of chemical pulp with the aim of achieving improved heat economy in a digester system having a vessel (1) for impregnation and a vessel (2) for cooking the impregnated cellulose chips. A part of the black liquor (14) withdrawn from the digester (2) is added at the beginning of a transfer system (4) to increase the temperature of the chips mixture in the transfer system (4). A fraction of the transport fluid (10) from the transfer system (4) that is continuously withdrawn from the impregnated chips fed into the top of the digester is returned to the impregnation vessel (1) at essentially the maintained transfer temperature.

The method is for feeding a chips-slurry from a low-pressure to a high-pressure system during the continuous cooking of chemical cellulose pulp. The feed takes place through a sluice feeder 53′ between these systems. The sluice feeder is provided with a rotor with through-pockets 1, 2 that are alternately connected with the low- or the high-pressure system. A recirculation line 54′, that has a high-pressure pump 57′, extends from the first outlet 53b′ of the sluice feeder to the second inlet 53c′ of the sluice feeder for transporting the fluid that has been expelled from the pockets of the sluice feeder when these are located in their first position. The fluid expels the chips mixture from the pockets of the sluice feeder in their second position and is essentially exclusively constituted by the fluid that has been expelled from the pockets in their first position.

A method and an apparatus for preparing cellulose pulp, in which a lignin-containing raw material is impregnated with impregnation liquor and the impregnated raw material is cooked. The black liquor obtained by cooking is concentrated in an evaporation plant integrated in a chemical recovery plant. In the impregnation, the lignin-containing raw material is impregnated with a circulating alkaline impregnating liquor, which impregnating liquor is concentrated by evaporating water from it in at least one evaporator unit of the evaporation plant arranged in the chemical recovery plant of a pulp mill.

The invention provides a mulberry bark slurry used for calligraphy and painting paper and a production method thereof, the method comprises the following steps: a)peeling and removing the impurities of mulberry bark, immersing by clear water for 4-12 hours; b)scouring and bleaching mulberry bark, wherein alkali temperature is 80-85 DEG C, by metering with NaOH, the alkali concentration accounts for 5-25% of absolute dry weight of the mulberry bark, hydrogen peroxide amount accounts for 0.5-5% of absolute dry weight of mulberry bark, anthraquinone amount accounts for 0.05-1% of absolute dry weight of mulberry bark, boiling osmotic agent amount accounts for 0.5-1% of absolute dry weight of mulberry bark, Na2SiO3 amount accounts for 1-10% of absolute dry weight of mulberry bark, MgSO4 amount accounts for 0.05-0.5% of absolute dry weight of mulberry bark, liquid ratio is 1: 3-20; c)performing pulp washing, wherein pH value of slurry is 7.0-8.0; d)cutting off; and e)performing pulp refining by a double disc refiner, wherein the refiner gap is 0.05-1.5mm, the slurry concentration is controlled at 20-30%, and forming small pulp pellets. The method has the advantages of simple process and easy operation, pulping is carried out without chlorine by combination of scouring and bleaching at low temperature, scouring and bleaching effects can be increased by adding a boiling auxiliary agent, a boiling osmotic agent and a bleaching stabilizing agent, the produced mulberry bark slurry has the advantages of high yield and good whiteness, and can be used for producing calligraphy and painting paper with high, middle and low grades.

The pulping and paper-making method adopts the material includes dried leaf, stem peel and fruit leftover of coconut, palm, areca, banana and pineapple. The production process includes material analysis, preparing material, pulping, recovering black liquor, making pulp sheet and making paper. The present invention utilizes the waste, is economic, environment friendly, wide in application range and reasonable in technological process.

The invention relates to a feed arrangement for feeding chips to chip bins (1) in the production of cellulose pulp in continuous digesters (16), in which the chip bin is constituted by a treatment vessel having a top and a bottom, in which the chips are fed into the top (13) of the treatment vessel and fed out via the bottom of the treatment vessel using suitable lock members (10, 11). Distribution devices (4a, 4b) for the addition of steam are disposed in the treatment vessel so as to heat the chips to a level above 80° C., preferably around 100° C., when the chips are fed out via the bottom of the treatment vessel.

By virtue of the fact that the chips are fed into the treatment vessel via at least one liquid lock (30) and the treatment vessel is otherwise sealed off, the quantity of driven-off gases from the chip bin is reduced to a minimum, at the same time as an effective utilization of available energy is obtained.

The invention relates to a method for separating non-wood lignocellulosic biomass lignin from pulp lignin with composite solvents. The method comprises the steps of extraction, separation and purification. The method utilizes sodium hydroxide/urea/thiourea/aqueous solution systems to separate much wheat straw lignin successfully at low temperature, the receiving rate of crude lignin reaches 60%, the receiving rate of pure lignin reaches 30%, and the purity of the isolated lignin can reach 99%. The time span of separating processes is very short and only needs 16 minutes, thereby protecting the chemical structure of the lignin effectively, and keeping ester linkages between lignin molecules in a relatively intact mode.

The invention relates to a comprehensive straw utilization method, which belongs to the technical field of comprehensive biomass material utilization. The method mainly comprises the following key steps: straw cutting, dry dedusting, hot-water washing for sand removal, continuous cooking, discharge and reception, multi-stage countercurrent washing, multi-stage high-concentration pulping, fiber grading, long fiber concentration, long fiber curing, long fiber pulping, production of corrugated paper from long fibers, short fiber concentration, production of fuel ethanol and solid pellet fuel by enzymolysis, fermentation and distillation of short fibers and the like. The method has the advantages that the high-value comprehensive utilization of each component of straw material is realized, chemicals are not added, a water system is closed and circulated, and no wastewater is discharged; the tiny fiber component has a large specific surface area and high enzymolysis efficiency; the corrugated paper produced from the long fiber component has high strength and good quality; and applying the tiny fiber component to an enzymolysis system not only increases the enzymolysis of the material, but also greatly reduces the cost of saccharide enzymolysis, thus promoting the development of the comprehensive biomass utilization technology.

The invention discloses a method for preparing cellulose nanocrystals. The method comprises the following steps of: (1) putting refined cotton linter into water of which the mass is 10 to 20 times that of the refined cotton linter, and performing ultrasonic stirring in an ultrasonic generator for 4 to 8 hours; (2) continuously adding a 0.5mol/L sulfuric acid aqueous solution of which the mass is 5 to 8 times that of the refined cotton linter and a 0.5mol/L hydrochloric acid aqueous solution of which the mass is 2 to 6 times that of the refined cotton linter into the ultrasonic generator, and performing ultrasonic stirring at the temperature of between 30 and 60 DEG C for 8 to 12 hours; and (3) washing a solid product obtained in the step (2) by using water until the pH value is 6 to 7. The method is simple in process and low in cost; and the prepared cellulose nanocrystals are uniform in granularity and high in performance.

One aspect of this invention relates to a method and digester for reducing the deposition of calcium-based scale in a wood chip digester including extraction from the digester of first and second quantities of cooking liquor having respective first and second calcium concentrations, treating the extracted cooking liquors to produce a cooking liquor having a calcium concentration less that the calcium concentration of the either of the first and second extracted cooking liquors, and, reintroducing the treated cooking liquor to the digester. Another aspect of this invention relates to a method and digester in which through put through the digester is increased by the continuous addition of process liquor into the digester preferably at an upper region of the digester.