CN112593434A - Sulfate pulping method for eucommia ulmoides - Google Patents
Sulfate pulping method for eucommia ulmoides Download PDFInfo
- Publication number
- CN112593434A CN112593434A CN202011453998.2A CN202011453998A CN112593434A CN 112593434 A CN112593434 A CN 112593434A CN 202011453998 A CN202011453998 A CN 202011453998A CN 112593434 A CN112593434 A CN 112593434A
- Authority
- CN
- China
- Prior art keywords
- pulping
- cooking
- pulp
- controlled
- eucommia
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C3/00—Pulping cellulose-containing materials
- D21C3/02—Pulping cellulose-containing materials with inorganic bases or alkaline reacting compounds, e.g. sulfate processes
- D21C3/022—Pulping cellulose-containing materials with inorganic bases or alkaline reacting compounds, e.g. sulfate processes in presence of S-containing compounds
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C3/00—Pulping cellulose-containing materials
- D21C3/22—Other features of pulping processes
- D21C3/222—Use of compounds accelerating the pulping processes
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C3/00—Pulping cellulose-containing materials
- D21C3/22—Other features of pulping processes
- D21C3/26—Multistage processes
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
- D21C9/06—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents in filters ; Washing of concentrated pulp, e.g. pulp mats, on filtering surfaces
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21D—TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
- D21D5/00—Purification of the pulp suspension by mechanical means; Apparatus therefor
- D21D5/02—Straining or screening the pulp
- D21D5/06—Rotary screen-drums
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
- D21H11/12—Pulp from non-woody plants or crops, e.g. cotton, flax, straw, bagasse
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Paper (AREA)
Abstract
The invention relates to the technical field of pulping, in particular to a sulfate pulping method for eucommia ulmoides. The sulfate pulping method for eucommia ulmoides comprises the following steps: A) cooking eucommia wood chips by a sulfate method to prepare pulp to obtain a standby material; in the cooking pulping process, firstly heating to 125-135 ℃, carrying out primary heat preservation, then heating to 160-175 ℃, and carrying out secondary heat preservation; B) washing the spare material with black liquor, and squeezing for dehydration; C) screening the material subjected to extrusion dehydration by adopting a pressure screen to obtain good pulp; D) and bleaching the good pulp to prepare pulp. The pulping method provided by the invention not only improves the value of the eucommia ulmoides material belonging to the leftover bits and pieces, but also can effectively save forestry resources, the pulping cost is lower, the quality of the prepared pulp is better, and the requirements of high-grade paper production can be completely met.
Description
Technical Field
The invention relates to the technical field of pulping, in particular to a sulfate pulping method for eucommia ulmoides.
Background
The paper making industry is a traditional industry, is closely related to the development of national economy and social career, relates to the fields of cultural transmission, civil life and the like, and the consumption level of paper and paperboard is a mark for measuring the modernization level and the civilization degree of the country.
However, China is a country with serious shortage of wood resources, the indexes of the primary wood pulp such as drainage performance, tensile strength and tearing index are obviously superior to those of non-wood fiber, and a large amount of wood pulp fiber needs to be consumed every year in China. However, the domestic forest resources cannot support huge demand, so that China needs to import a large amount of wood pulp and wood chips and a large amount of waste paper every year, along with the limitation of imported waste paper, the pressure of fiber raw materials in the paper making industry of China becomes more severe, how to improve the self-sufficiency rate of wood pulp and reduce the dependence degree on the imported wood pulp and wood chips is a major subject in the paper making industry of China. On the other hand, because the growth cycle of wood, especially softwood, i.e. coniferous tree, is too long, the age of the tree is generally more than 15 years, so that large-scale pulping and papermaking enterprises and pulping production lines are generally required to produce virgin chemical wood pulp by hardwood, i.e. hardwood with shorter growth cycle, in order to solve the problem of shortage of wood raw material resources.
Eucommia bark, eucommia bark family, belongs to tall trees with the height of 20m, the bark is gray brown and coarse, contains rubber, and is broken and pulled to form a plurality of filaments. The tender branches have yellow brown hair, the alopecia becomes clean after a while, and the old branches have obvious skin pores. The bud is oval, bright, red brown, and has 6-8 scales and hair at the edge.
Leaf-elliptical, oval or oblong, thin, leather, 6-15 cm long and 3.5-6.5 cm wide. The base part is circular or wedge-shaped, and the tip is tapered; dark green above, brown and soft hair at first time, baldness soon, slight wrinkles in old leaves, light green below, brown hair at first time, and hair only on pulse later. 6-9 pairs of lateral veins are sunken in the upper part of the vein, slightly protrude in the lower part, have sawteeth on the edge, have 1-2 cm long petioles, and have grooves on the upper part, and are scattered to grow hair.
The peanuts are arranged at the base of the branches in the current year, and the male flowers have no perianth; the pedicel is about 3mm long and has no hair; the bract is inverted egg-shaped and spoon-shaped, the length is 6-8 mm, the top end is round, the edge is provided with eyelashes, and the eyelashes fall off early; the stamen is about 1 cm long, without hair, the filament is about 1mm long, the drug compartment is prominent, the anther is slender, and there is no degenerated pistil. The female flower grows singly, the bract is inverted into an egg shape, the flower stalk is 8mm long, the ovary is hairless, 1 chamber is flat and long, the tip is 2 cracks, and the ovary stalk is extremely short. The wing fruit is flat, oblong, 3-3.5 cm long, 1-1.3 cm wide, 2 cracks at the tip, wedge-shaped at the base and thin wings around.
The nut is in the center and slightly protruded, the ovary handle is 2-3 mm long, and the joint is arranged at the joint of the nut and the fruit stem. The seeds are flat and linear, the length is 1.4-5 cm, the width is 3mm, and the two ends are round. Blooming in early spring, and fruit ripening after autumn.
The eucommia ulmoides trees are special precious tree species in China, mainly grow in sparse forests at 300-500 m elevation, valley lands or low slopes, are not strict in soil selection, and can grow on barren laterites or rock cliffs. The cultivation method is favored by sunshine, mild humid climate, cold resistance and low requirement on soil, can be used for planting in hills and plains, can also be used for cultivation in sporadic land or four sides, is mainly distributed in the middle and lower reaches of Yangtze river and south provinces, and is widely planted at present due to huge medicinal value.
The most valuable parts of eucommia bark are bark and root bark, and the trunk belongs to leftover bits and pieces, so that the conventional treatment value is low, if the eucommia bark pulp can be used for pulping, the value is greatly improved, on one hand, forestry resources can be effectively saved, and on the other hand, the added value of papermaking is high.
Disclosure of Invention
In view of the above, the technical problem to be solved by the present invention is to provide a sulfate pulping method for eucommia ulmoides, which has low cost and excellent quality of the prepared pulp.
The invention provides a sulfate pulping method for eucommia ulmoides, which comprises the following steps:
A) cooking eucommia wood chips by a sulfate method to prepare pulp to obtain a standby material;
in the cooking pulping process, firstly heating to 125-135 ℃, carrying out primary heat preservation, then heating to 160-175 ℃, and carrying out secondary heat preservation;
B) washing the spare material with black liquor, and squeezing for dehydration;
C) screening the material subjected to extrusion dehydration by adopting a pressure screen to obtain good pulp;
D) and bleaching the good pulp to prepare pulp.
Preferably, the length of the eucommia wood chips is 15-30 mm, and the thickness of the eucommia wood chips is 2.5-6 mm;
the water content of the eucommia wood chips is 10-50%;
the qualification rate of the eucommia wood chips is controlled to be more than or equal to 80 percent;
the eucommia wood chips are prepared from eucommia trunks.
Preferably, the vulcanization degree of the eucommia wood chips subjected to cooking pulping by adopting a sulfate method is controlled to be 15-25%;
the pressure of the cooking pulping is 0.70-0.80 MPa.
Preferably, step a) specifically comprises:
mixing eucommia wood chips, sodium hydroxide solid, sodium sulfate and water, and performing cooking pulping to obtain a standby material;
the mass ratio of the total mass of the sodium hydroxide and the sodium sulfide to the eucommia wood chips is 16-20: 100, respectively;
the cooking liquor ratio is 1: 3.5 to 3.7.
Preferably, in the step a), after the temperature is raised to 125-135 ℃, the method further comprises: carrying out 2-3 times of operation of discharging non-condensable gas in the cooking environment;
the time for heating to 125-135 ℃ is controlled to be 30-50 min;
the first heat preservation time is not more than 30 min.
Preferably, in the step a), after the temperature is increased to 160-175 ℃, the method further comprises: carrying out 3-5 times of operation of discharging non-condensable gas in the cooking environment;
the time for heating to 160-175 ℃ is controlled to be 30-50 min;
the time for the second heat preservation is 30-50 min.
Preferably, in the step B), the Baume degree of the black liquor is more than or equal to 8.0Be, the free alkali of the black liquor is more than or equal to 5.0g/L, and the fiber content of the black liquor is less than or equal to 0.01 g/L;
the residual alkali residue after the black liquor washing is not more than 150 mg/L.
Preferably, in step B), subjecting the stock to black liquor washing comprises:
and carrying out four-stage black liquor countercurrent washing on the used material.
Preferably, in the step C), the screen gap of the pressure screen is controlled to be 0.2-0.5 mm;
the parameters for screening by using the pressure screen comprise:
the pulp inlet pressure is controlled to be 3.0-7.0 bar, the pressure difference of an inlet and an outlet is controlled to be 20-30 KPa, and the flow ratio of the slag pulp to the good pulp is controlled to be 20-30%; the operation load is controlled to be 40-60%.
Preferably, in the step D), the bleaching agent used for bleaching is hydrogen peroxide;
after bleaching, the whiteness of the good pulp is controlled to be 27 to 36 percent ISO, and the dust is not higher than 500mm2/kg。
The invention provides a sulfate pulping method for eucommia ulmoides, which comprises the following steps: A) cooking eucommia wood chips by a sulfate method to prepare pulp to obtain a standby material; in the cooking pulping process, firstly heating to 125-135 ℃, carrying out primary heat preservation, then heating to 160-175 ℃, and carrying out secondary heat preservation; B) washing the spare material with black liquor, and squeezing for dehydration; C) screening the material subjected to extrusion dehydration by adopting a pressure screen to obtain good pulp; D) and bleaching the good pulp to prepare pulp. The pulping method provided by the invention not only improves the value of the eucommia ulmoides material belonging to the leftover bits and pieces, but also can effectively save forestry resources, the pulping cost is lower, the quality of the prepared pulp is better, and the requirements of high-grade paper production can be completely met.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides a sulfate pulping method for eucommia ulmoides, which comprises the following steps:
A) cooking eucommia wood chips by a sulfate method to prepare pulp to obtain a standby material;
in the cooking pulping process, firstly heating to 125-135 ℃, carrying out primary heat preservation, then heating to 160-175 ℃, and carrying out secondary heat preservation;
B) washing the spare material with black liquor, and squeezing for dehydration;
C) screening the material subjected to extrusion dehydration by adopting a pressure screen to obtain good pulp;
D) and bleaching the good pulp to prepare pulp.
In some embodiments of the present invention, the eucommia ulmoides wood chips have a length of 15 to 30mm and a thickness of 2.5 to 6 mm. In certain embodiments, the length of the eucommia wood chips is 25mm, 28mm, or 30 mm. In certain embodiments, the eucommia wood chips have a thickness of 2.5mm, 3.1mm, or 3.3 mm.
In some embodiments of the invention, the moisture content of the eucommia ulmoides wood chips is 10% to 50%. In some embodiments, the moisture content of the eucommia wood chips is 21.6%, 22.2%, or 25.3%.
In some embodiments of the invention, the qualification rate of the eucommia ulmoides wood chips is controlled to be more than or equal to 80%. In some embodiments, the yield of eucommia wood chips is controlled to be 80%, 85%, or 88.3%. The yield here means the mass percentage of the eucommia wood chips satisfying the above requirements for length, thickness and water content to the whole eucommia wood chips.
In certain embodiments of the invention, the eucommia wood chips are prepared from the trunk of eucommia. Specifically, the following may be mentioned:
cutting and screening the trunk of eucommia ulmoides.
After the eucommia wood chips are obtained, the eucommia wood chips are steamed and boiled by a sulfate method for pulping to obtain a standby material.
In some embodiments of the invention, the sulfuration degree of the eucommia ulmoides wood chips subjected to cooking pulping by using a sulfate method is controlled to be 15-25%. In some embodiments, the degree of sulfidation of the eucommia wood chips is controlled to 16%, 17% or 18% by cooking pulping using the sulfate process.
In some embodiments of the invention, the pressure of the cooking pulping is 0.70-0.80 MPa. In certain embodiments, the pressure of the cooking pulping is 0.75MPa, 0.78MPa, or 0.80 MPa.
In some embodiments of the invention, eucommia wood chips, sodium hydroxide solids, sodium sulfate and water are mixed and subjected to cooking pulping to obtain a stock.
In some embodiments of the invention, the mass ratio of the total mass of the sodium hydroxide and the sodium sulfide to the eucommia wood chips is 16-20: 100. in certain embodiments, the mass ratio of the total mass of sodium hydroxide and sodium sulfide to eucommia wood chips is 17: 100. 18: 100 or 19: 100.
in certain embodiments of the present invention, the raw material of the cooking pulping further comprises a cooking aid. In certain embodiments of the present invention, the cooking aid comprises an anthraquinone-based compound and/or a penetrant. In certain embodiments, the cooking aid is a type 6873 of leshi brand.
In some embodiments of the invention, the mass ratio of the cooking aid to the eucommia ulmoides wood chips is 0.03-0.04: 100. in certain embodiments, the mass ratio of the cooking aid to eucommia wood chips is 0.0375: 100.
in certain embodiments of the invention, the liquor ratio of the cooking is 1: 3.5 to 3.7. In certain embodiments, the liquor ratio of the cooking is 1: 3.5, 1: 3.6 or 1: 3.7.
in certain embodiments of the invention, the cooking pulping is performed in a digester.
In the cooking pulping process, the temperature is firstly increased to 125-135 ℃, the first heat preservation is carried out, then the temperature is increased to 160-175 ℃, and the second heat preservation is carried out.
In some embodiments of the present invention, after the temperature is raised to 125-135 ℃, the method further comprises: and 2-3 times of operation of discharging non-condensable gas in the cooking environment. Specifically, the following may be mentioned: and (5) carrying out 2-3 times of operation of discharging the non-condensable gas in the cooking pot. In some embodiments, the temperature is first raised to 130 deg.C, 132 deg.C or 135 deg.C. In some embodiments, 3 operations of exhausting non-condensable gas in the digester are performed.
In some embodiments of the present invention, the time for heating to 125-135 ℃ is controlled to be 30-50 min. In some embodiments, the time for heating to 125-135 ℃ is controlled to be 35min or 35.5 min.
In certain embodiments of the invention, the first incubation time does not exceed 30 min. In certain embodiments, the time for the first incubation is 15min or 20 min.
In some embodiments of the present invention, after the temperature is increased to 160-175 ℃, the method further comprises: and 3-5 times of operation of discharging non-condensable gas in the cooking environment. Specifically, the following may be mentioned: and (5) discharging the non-condensable gas in the cooking pot for 3-5 times. In certain embodiments, the temperature is increased to 175 deg.C, 170 deg.C, or 168 deg.C. In some embodiments, 3 operations of exhausting non-condensable gas in the digester are performed.
In some embodiments of the present invention, the time for heating to 160-175 ℃ is controlled to be 30-50 min. In some embodiments, the time for heating to 160-175 ℃ is controlled to be 40min or 35 min.
In some embodiments of the invention, the time for the second heat preservation is 30-50 min. In certain embodiments, the time for the second incubation is 55min or 50 min.
In some embodiments of the present invention, after the cooking for pulping, the method further comprises: washing and filtering. And filtering the washed product and the washing liquid together, wherein the filtered oversize material is a spare material, and the filtered solution is black liquor. The washing method of the present invention is not particularly limited, and a washing method known to those skilled in the art may be used. The method of filtration is not particularly limited in the present invention, and the filtration steps and parameters known to those skilled in the art may be used.
After the spare material is obtained, the spare material is washed by black liquor and is squeezed for dehydration.
In certain embodiments of the invention, the Baume degree of the black liquor is greater than or equal to 8.0Be, the free alkali of the black liquor is greater than or equal to 5.0g/L, and the fiber content of the black liquor is less than or equal to 0.01 g/L. In certain embodiments, the baume degree of the black liquor is 8.15Be, 8.2Be, or 8.7 Be. In certain embodiments, the black liquor has a free alkali of 5.0g/L, 5.7g/L, or 6.5 g/L. In certain embodiments, the black liquor has a fiber content of 0.008g/L, 0.01g/L, or 0.009 g/L.
In certain embodiments of the invention, subjecting the stock to black liquor washing comprises:
and carrying out four-stage black liquor countercurrent washing on the used material.
The method and parameters for the counter-current washing of the black liquor are not particularly limited in the present invention, and those well known to those skilled in the art can be used.
In certain embodiments of the invention, the residual alkali balance after black liquor washing does not exceed 150 mg/L. In certain embodiments, the residual alkali balance after black liquor washing is 6.2mg/L, 7.17mg/L, or 7.55 mg/L.
The method and parameters for press dewatering are not particularly limited in the present invention, and those well known to those skilled in the art can be used.
And after extrusion dehydration, screening the extruded and dehydrated material by adopting a pressure screen to obtain good pulp.
In some embodiments of the invention, the screen gap of the pressure screen is controlled to be 0.2-0.5 mm. In certain embodiments, the screen slots of the pressure screen are controlled at 0.2 mm.
In certain embodiments of the invention, the parameters for screening with a pressure screen include:
the pulp inlet pressure is controlled to be 3.0-7.0 bar, the pressure difference of an inlet and an outlet is controlled to be 20-30 KPa, and the flow ratio of the slag pulp to the good pulp (the flow ratio of the slag pulp to the good pulp at the outlet) is controlled to be 20-30%; the operation load is controlled to be 40-60%.
In certain embodiments, the feed pressure is controlled to be 3.0bar or 5.0 bar. In some embodiments, the inlet-outlet pressure differential is controlled to be 20KPa or 25 KPa. In certain embodiments, the flow ratio of the slurry to the accepts is controlled to be 20% or 25%. In certain embodiments, the operating load control is 40%.
And bleaching the good pulp to obtain the pulp.
In certain embodiments of the present invention, the bleaching agent employed is hydrogen peroxide.
In certain embodiments of the invention, following bleaching, the accepts whiteness is controlled at 27% to 36% ISO, the dust is no higher than 500mm2In terms of/kg. In certain embodiments, the accepts whiteness is controlled at 27.6% ISO, 31.3% ISO, or 35% ISO. In certain embodiments, the dust is 375mm2/kg、355mm2Per kg or 290mm2/kg。
In certain embodiments of the invention, the prepared slurry may be stored in a holding tower for use.
The source of the above-mentioned raw materials is not particularly limited in the present invention, and may be generally commercially available.
In the pulping method provided by the invention, the adopted raw materials are eucommia ulmoides trunks with lower conventional treatment value, the pulping cost is lower, the value of the eucommia ulmoides material belonging to the leftover is improved, and the forestry resources can be effectively saved.
The pulp obtained by the pulping method provided by the invention has good quality and can completely meet the requirements of high-grade paper production.
In the process of cooking and pulping, the invention discharges non-condensable gas in the cooking pot for many times, and can lead the heat in the pot to be convected, lead the upper, middle and lower temperatures to be consistent and improve the cooking uniformity.
The invention can reasonably control the pressure, temperature, time and chemical consumption of the cooking according to the quality of the pulp required by production in the process of cooking and pulping.
In order to further illustrate the present invention, the sulfate process for eucommia ulmoides provided by the present invention will be described in detail with reference to the following examples, which should not be construed as limiting the scope of the present invention.
The starting materials used in the following examples are all generally commercially available.
The tensile strength testing instrument is manufactured by Swedish L & W company, model number: SE 062; the tearing strength tester is manufactured by Swedish L & W company, and has the following model: 009; the bursting strength tester is manufactured by Swedish L & W company, and has the following model: 983403, respectively; the breaking length is measured by a tensile strength meter, the tearing index is measured by a tearing strength tester, and the burst index is measured by a burst tester.
Example 1
1) After the trunks of the eucommia ulmoides are chipped and screened, the length of the wood chips is 25mm, the thickness of the wood chips is 2.5mm, the qualification rate of the wood chips is controlled to be 80% according to the mass percentage, and the water content of the wood chips is 21.6%;
2) mixing the wood chips prepared in the step 1), sodium hydroxide solid, sodium sulfate, a cooking aid (Leishi cooking aid, model 6873) and water, cooking and pulping in a cooking pot, wherein the cooking liquor ratio is controlled to be 1: 3.5, the mass ratio of the total mass of the sodium hydroxide and the sodium sulfide to the eucommia wood chips is 17: 100, the mass ratio of the cooking aid to the eucommia wood chips is 0.0375: 100, controlling the vulcanization degree to be 16 percent, controlling the pressure in a digester to be 0.75Mpa, controlling the heating rate in the cooking process, dividing the heating process into 2 times, controlling the first heating to be 130.0 ℃, carrying out 3 times of operation of discharging non-condensable gas in the digester, controlling the heating time to be 35.0min, controlling the heat preservation time to be 15.0min when the highest temperature is reached, controlling the second heating to be 175 ℃, carrying out 3 times of operation of discharging non-condensable gas in the digester, controlling the heating time to be 40.0min, controlling the heat preservation time to be 55min when the highest temperature is reached, and then washing and filtering to prepare a spare material and black liquor;
3) putting the prepared materials prepared in the step 2) into a washer, carrying out four-stage black liquor countercurrent washing, and carrying out extrusion dehydration, wherein the residual alkali is 6.2mg/L after washing; the Baume degree of the black liquor is 8.15Be, the free alkali of the black liquor is 5.0g/L, and the fiber content of the black liquor is 0.008 g/L;
4) feeding the extruded and dehydrated material into a pressure screen for screening operation, wherein the screen gap of the pressure screen is controlled to be 0.2mm, the pulp inlet pressure is controlled to be 3.0bar, the pressure difference of an inlet and an outlet is controlled to be 20KPa, and the flow ratio of the slag pulp to the good pulp is controlled to be 20%; controlling the operation load to be 40%, and screening out fine pulp;
5) bleaching the fine pulp by adopting hydrogen peroxide, wherein the whiteness of the fine pulp is controlled to be 27.6 percent ISO and the dust is 375mm2Per kg (dust over 0.1 square millimeter) to prepare a slurry;
6) feeding the slurry prepared in the step 5) into a slurry storage tower for storage.
Example 2
1) After the trunks of the eucommia ulmoides are chipped and screened, the length of the wood chips is 28mm, the thickness of the wood chips is 3.1mm, the qualification rate of the wood chips is controlled to be 85% according to the mass percentage, and the water content of the wood chips is 22.2%;
2) mixing the wood chips prepared in the step 1), sodium hydroxide solid, sodium sulfate, a cooking aid (Leishi cooking aid, model 6873) and water, cooking and pulping in a cooking pot, wherein the cooking liquor ratio is controlled to be 1: 3.6, the mass ratio of the total mass of the sodium hydroxide and the sodium sulfide to the eucommia wood chips is 18: 100, the mass ratio of the cooking aid to the eucommia wood chips is 0.0375: 100, controlling the vulcanization degree to be 17 percent, controlling the pressure in a digester to be 0.78Mpa, controlling the heating rate in the cooking process, dividing the heating process into 2 times, controlling the first heating to be 132 ℃, carrying out 3 times of operation of discharging non-condensable gas in the digester, controlling the heating time to be 35.0min, controlling the heat preservation time to be 20.0min when the highest temperature is reached, controlling the second heating to be 170 ℃, carrying out 3 times of operation of discharging non-condensable gas in the digester, controlling the heating time to be 40.0min, controlling the heat preservation time to be 50min when the highest temperature is reached, and then washing and filtering to prepare a spare material and black liquor;
3) putting the prepared materials prepared in the step 2) into a washer, carrying out four-stage black liquor countercurrent washing, and carrying out extrusion dehydration, wherein the residual alkali is 7.17mg/L after washing; the Baume degree of the black liquor is 8.2Be, the free alkali of the black liquor is 5.7g/L, and the fiber content of the black liquor is 0.01 g/L;
4) feeding the extruded and dehydrated material into a pressure screen for screening operation, wherein the screen gap of the pressure screen is controlled to be 0.2mm, the pulp inlet pressure is controlled to be 5.0bar, the pressure difference of an inlet and an outlet is controlled to be 25KPa, and the flow ratio of the slag pulp to the fine pulp is controlled to be 25%; controlling the operation load to be 40%, and screening out fine pulp;
5) bleaching the fine pulp by adopting hydrogen peroxide, controlling the whiteness of the fine pulp to be 31.3 percent ISO and controlling the whiteness of dust to be 355mm2Per kg (dust over 0.1 square millimeter) to prepare a slurry;
6) feeding the slurry prepared in the step 5) into a slurry storage tower for storage.
Example 3
1) After the trunks of the eucommia ulmoides are chipped and screened, the length of the wood chips is 30mm, the thickness of the wood chips is 3.3mm, the qualification rate of the wood chips is controlled to be 88.3% according to the mass percentage, and the water content of the wood chips is 25.3%;
2) mixing the wood chips prepared in the step 1), sodium hydroxide solid, sodium sulfate, a cooking aid (Leishi cooking aid, model 6873) and water, cooking and pulping in a cooking pot, wherein the cooking liquor ratio is controlled to be 1: 3.7, wherein the mass ratio of the total mass of the sodium hydroxide and the sodium sulfide to the eucommia wood chips is 19: 100, the mass ratio of the cooking aid to the eucommia wood chips is 0.0375: 100, controlling the degree of vulcanization to be 18 percent, controlling the pressure in a digester to be 0.80Mpa, controlling the heating rate in the cooking process, dividing the heating process into 2 times, controlling the first heating to be 135 ℃, carrying out 3 times of operation of discharging non-condensable gas in the digester, controlling the heating time to be 35.5min, controlling the heat preservation time to be 15.0min when the highest temperature is reached, controlling the second heating to be 168 ℃, carrying out 3 times of operation of discharging non-condensable gas in the digester, controlling the heating time to be 35.0min, controlling the heat preservation time to be 55min when the highest temperature is reached, and then washing and filtering to prepare a spare material and black liquor;
3) putting the prepared materials prepared in the step 2) into a washer, carrying out four-stage black liquor countercurrent washing, and carrying out extrusion dehydration, wherein the residual alkali is 7.55mg/L after washing; the Baume degree of the black liquor is 8.7Be, the free alkali of the black liquor is 6.5g/L, and the fiber content of the black liquor is 0.009 g/L;
4) feeding the extruded and dehydrated material into a pressure screen for screening operation, wherein the screen gap of the pressure screen is controlled to be 0.2mm, the pulp inlet pressure is controlled to be 5.0bar, the pressure difference of an inlet and an outlet is controlled to be 25KPa, and the flow ratio of the slag pulp to the fine pulp is controlled to be 25%; controlling the operation load to be 40%, and screening out fine pulp;
5) bleaching the fine pulp by adopting hydrogen peroxide, controlling the whiteness of the fine pulp to be 35 percent ISO and controlling the dust to be 290mm2Per kg (dust over 0.1 square millimeter) to prepare a slurry;
6) feeding the slurry prepared in the step 5) into a slurry storage tower for storage.
The process parameters and effect data in the pulping methods of examples 1-3 are shown in table 1.
TABLE 1 Process parameters and Effect data for the pulping methods of examples 1 to 3
In Table 1, CIE is the visual whiteness, L is the lightness index, a and b are the chroma indexes, a represents the degree of red and green of the paper color, and b represents the degree of yellow and blue of the paper color.
As can be seen from Table 1, the length of the fiber obtained by the pulping method provided by the invention is more than 0.94 mm; the fracture length is more than 5.1km at the percussion degree of 34SR, and is more than 6.8km at the percussion degree of 40 SR; at a click rate of 34SR, the tear index is greater than 4.6mN · m2(iv)/g, at a click rate of 40SR, a tear index of more than 6.3 mN.m2(ii)/g; at a percussion degree of 34SR, the burst index is greater than 2.7kpa · m2(iv)/g, at a tap degree of 40SR, a tear index of greater than 3.1kpa · m2/g。
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A sulfate pulping method for eucommia ulmoides comprises the following steps:
A) cooking eucommia wood chips by a sulfate method to prepare pulp to obtain a standby material;
in the cooking pulping process, firstly heating to 125-135 ℃, carrying out primary heat preservation, then heating to 160-175 ℃, and carrying out secondary heat preservation;
B) washing the spare material with black liquor, and squeezing for dehydration;
C) screening the material subjected to extrusion dehydration by adopting a pressure screen to obtain good pulp;
D) and bleaching the good pulp to prepare pulp.
2. The pulping method according to claim 1, wherein the eucommia wood chips have a length of 15 to 30mm and a thickness of 2.5 to 6 mm;
the water content of the eucommia wood chips is 10-50%;
the qualification rate of the eucommia wood chips is controlled to be more than or equal to 80 percent;
the eucommia wood chips are prepared from eucommia trunks.
3. The pulping method according to claim 1, wherein the degree of sulfuration of the eucommia wood chips subjected to cooking pulping by a sulfate method is controlled to be 15-25%;
the pressure of the cooking pulping is 0.70-0.80 MPa.
4. The pulping method according to claim 1, wherein step a) specifically comprises:
mixing eucommia wood chips, sodium hydroxide solid, sodium sulfate and water, and performing cooking pulping to obtain a standby material;
the mass ratio of the total mass of the sodium hydroxide and the sodium sulfide to the eucommia wood chips is 16-20: 100, respectively;
the cooking liquor ratio is 1: 3.5 to 3.7.
5. The pulping method according to claim 1, wherein in the step A), after the temperature is raised to 125-135 ℃, the method further comprises the following steps: carrying out 2-3 times of operation of discharging non-condensable gas in the cooking environment;
the time for heating to 125-135 ℃ is controlled to be 30-50 min;
the first heat preservation time is not more than 30 min.
6. The pulping method according to claim 1, wherein the step A) further comprises the following step of heating to 160-175 ℃: carrying out 3-5 times of operation of discharging non-condensable gas in the cooking environment;
the time for heating to 160-175 ℃ is controlled to be 30-50 min;
the time for the second heat preservation is 30-50 min.
7. The pulping method according to claim 1, wherein in the step B), the Baume degree of the black liquor is more than or equal to 8.0Be, the free alkali of the black liquor is more than or equal to 5.0g/L, and the fiber content of the black liquor is less than or equal to 0.01 g/L;
the residual alkali residue after the black liquor washing is not more than 150 mg/L.
8. A pulping process according to claim 1 wherein the step B) of black liquor washing the stock comprises:
and carrying out four-stage black liquor countercurrent washing on the used material.
9. The pulping method according to claim 1, wherein in the step C), the screen gap of the pressure screen is controlled to be 0.2-0.5 mm;
the parameters for screening by using the pressure screen comprise:
the pulp inlet pressure is controlled to be 3.0-7.0 bar, the pressure difference of an inlet and an outlet is controlled to be 20-30 KPa, and the flow ratio of the slag pulp to the good pulp is controlled to be 20-30%; the operation load is controlled to be 40-60%.
10. A pulping process according to claim 1 wherein in step D) the bleaching agent used is hydrogen peroxide;
after bleaching, the whiteness of the good pulp is controlled to be 27 to 36 percent ISO, and the dust is not higher than 500mm2/kg。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011453998.2A CN112593434A (en) | 2020-12-10 | 2020-12-10 | Sulfate pulping method for eucommia ulmoides |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011453998.2A CN112593434A (en) | 2020-12-10 | 2020-12-10 | Sulfate pulping method for eucommia ulmoides |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112593434A true CN112593434A (en) | 2021-04-02 |
Family
ID=75192177
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011453998.2A Pending CN112593434A (en) | 2020-12-10 | 2020-12-10 | Sulfate pulping method for eucommia ulmoides |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112593434A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113930991A (en) * | 2021-11-01 | 2022-01-14 | 岳阳林纸股份有限公司 | Cortex phellodendri pulping process |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103628348A (en) * | 2013-12-16 | 2014-03-12 | 吴建华 | Eucommia ulmoides paper |
| CN110438834A (en) * | 2019-08-08 | 2019-11-12 | 岳阳林纸股份有限公司 | A kind of camphorwood sulfate pulping technique |
| CN110886119A (en) * | 2019-11-14 | 2020-03-17 | 广西大学 | Method for preparing high-whiteness paper pulp by taking eucommia ulmoides leaf forest mode branches as raw materials |
| CN111826983A (en) * | 2020-06-06 | 2020-10-27 | 岳阳林纸股份有限公司 | Poplar rod core sulfate pulping process |
| CN111962320A (en) * | 2020-08-11 | 2020-11-20 | 岳阳林纸股份有限公司 | Sulfate pulping process for industrial hemp |
-
2020
- 2020-12-10 CN CN202011453998.2A patent/CN112593434A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103628348A (en) * | 2013-12-16 | 2014-03-12 | 吴建华 | Eucommia ulmoides paper |
| CN110438834A (en) * | 2019-08-08 | 2019-11-12 | 岳阳林纸股份有限公司 | A kind of camphorwood sulfate pulping technique |
| CN110886119A (en) * | 2019-11-14 | 2020-03-17 | 广西大学 | Method for preparing high-whiteness paper pulp by taking eucommia ulmoides leaf forest mode branches as raw materials |
| CN111826983A (en) * | 2020-06-06 | 2020-10-27 | 岳阳林纸股份有限公司 | Poplar rod core sulfate pulping process |
| CN111962320A (en) * | 2020-08-11 | 2020-11-20 | 岳阳林纸股份有限公司 | Sulfate pulping process for industrial hemp |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113930991A (en) * | 2021-11-01 | 2022-01-14 | 岳阳林纸股份有限公司 | Cortex phellodendri pulping process |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Iñiguez-Covarrubias et al. | Utilization of by-products from the tequila industry. Part 2: potential value of Agave tequilana Weber azul leaves | |
| CN110438834B (en) | Camphorwood sulfate pulping process | |
| CN102337687A (en) | Novel pulping process for obtaining high performance fiber at high yield from plants | |
| EP0488486B1 (en) | Method of producing pulp | |
| ES2740005T3 (en) | Process for the manufacture of paper, cardboard or cardboard using baerbab tree bark fibers, baobab fruit fibers and Natal fig tree fibers as paper raw material | |
| CN112593434A (en) | Sulfate pulping method for eucommia ulmoides | |
| CN110453519A (en) | A kind of pulping process of edible fungi residue | |
| Islam | Kenaf (Hibiscus cannabinus L., Malvaceae) research and development advances in Bangladesh: a review | |
| CN104452467A (en) | Thin natural color food wrapping paper and preparation method thereof | |
| CN110612833B (en) | Method for quickly breeding new germplasm bamboo-based sympodial bamboo seedlings for fibers | |
| CN104928962A (en) | Method for pulping corn stalk as a raw material and making natural-color household paper | |
| CN105284239A (en) | Method for promoting germination and sowing of Chinese scholar tree seeds | |
| Souza et al. | Wood and pulping properties of Eucalyptus urophylla and its hybrid grown by silvopastoral and conventional forest production models | |
| CN103850146A (en) | Pulp for viscose and preparation method of pulp | |
| Jahan et al. | Effect of harvesting age on the chemical and morphological properties of dhaincha (Sesbania aculeata) and its pulpability and bleachability. | |
| KR101520761B1 (en) | Paper using kudzu vine and manufacturing method thereof | |
| CN105625076A (en) | Environment-friendly unbleached paper | |
| CN101435170A (en) | Ginger terrestrial stem paper and manufacturing process thereof | |
| CN106049147B (en) | Paper mulberry sets semichemical method pulping process entirely | |
| CN113930991A (en) | Cortex phellodendri pulping process | |
| KR101035807B1 (en) | Natural adhesive gained from the Pourthiaea villosa's leaf and process for gaining it, and method manufacturing Korean paper with the adhesive | |
| CN114592380B (en) | Seedling paper suitable for mechanized transplanting and preparation method thereof | |
| WO2013082735A1 (en) | Chemical mechanical pulping method | |
| CN112012034B (en) | Preparation method of bamboo pulp, bamboo pulp and fiber | |
| CN106149435B (en) | Paper mulberry sets chemical pulping method entirely |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210402 |
|
| RJ01 | Rejection of invention patent application after publication |