CN115029947A

CN115029947A - Method for preparing APMP slurry by utilizing double screws pretreated by microorganisms

Info

Publication number: CN115029947A
Application number: CN202210576641.6A
Authority: CN
Inventors: 谢益民; 薛超; 曾红波; 刘涛; 罗文琪; 张功侠
Original assignee: Hubei Huahai Fiber Technology Co ltd
Current assignee: Hubei Huahai Fiber Technology Co ltd
Priority date: 2022-05-25
Filing date: 2022-05-25
Publication date: 2022-09-09

Abstract

The invention relates to a method for preparing APMP slurry by utilizing double screws pretreated by microorganisms, which comprises the steps of pretreating wood by using pycnoporus cinnabarinus, and then deeply researching the fiber morphology and the physical properties of the APMP slurry by using the pycnoporus cinnabarinus for pretreating the double screws so as to develop a new idea for the application of biological pulping in the paper making industry.

Description

Method for preparing APMP slurry by utilizing double screws pretreated by microorganisms

Technical Field

The invention relates to the field of papermaking, in particular to a method for preparing APMP (Alkaline Peroxide Mechanical pulp) by utilizing double screws pretreated by microorganisms.

Background

The paper industry is the industrial sector for the manufacture of various types of paper and board, including the pulp industry for the manufacture of paper pulp from wood, reed, bagasse, rice straw, wheat straw, cotton straw, hemp straw, cotton, etc., the paper and board industry, and the paper industry for the manufacture of coated, glazed, sized, laminated and other finished papers and patterned paper. The paper industry has an important position in national economy. The common pulping methods mainly include chemical methods, semi-chemical methods, chemical mechanical methods and the like, and according to different chemicals used, the common chemical pulping process also includes the following steps: a caustic soda process, a caustic soda-anthraquinone process, a sulfate process, a polysulfide pulping process, an oxygen-base process, and the like.

In various methods for preparing chemical mechanical pulp, the double-screw extrusion fluffer performs axial extrusion, kneading, tearing and other actions on pulp to strengthen fibers, so that good fiber separation is realized and the pulping purpose is achieved. The double-screw extrusion method gradually draws attention to the pulping and papermaking world at home and abroad due to the advantages of low energy consumption, high paper pulp quality, less pollution, wide raw material sources and the like. Although the double-screw extrusion method has a plurality of advantages, because the broken fibers generated in the pulping process are more, and the low-temperature alkaline leaching substances contained in the raw materials are gradually accumulated along with the recycling of the waste water, on one hand, the substances can inhibit the dissolution of organic matters in the wood chips, on the other hand, the alkali consumption is increased to ensure the strength of the paper sheets in order to consume a large amount of alkali, and the process is repeated in cycles, and finally, the alkali consumption is large.

With the progress of science and technology, biotechnology is more and more common in industrial production, and rapid development of other industries is also driven. At present, the biotechnology in the papermaking field mainly focuses on pulping, bleaching, wastewater treatment, waste paper deinking and other processes, and is widely applied. The bio-mechanical pulping utilizes microorganisms or enzymes to pretreat fiber raw materials, and then carries out pulping to separate fibers from each other, and has the advantages of low energy consumption, high strength and low pollution. The biochemical pulping refers to firstly carrying out biological pretreatment and then carrying out pulping by using chemical treatment, and has the advantages of reducing the hardness of paper pulp under the condition of not changing the dosage of the chemical, or reducing the dosage of the chemical and the consumption of energy under the same hardness. At present, white rot fungi are widely used in the field of pulping biology, for example, CN1724414A discloses a method for effectively decoloring pulping waste liquor by using white rot fungi, and CN107938411A discloses a method for pulping by removing lignin in plant fibers by using a compound biological enzyme agent containing white rot fungi.

At present, the bio-paper making technology mainly uses white rot fungi as main strains, and the pulping technology that other strains such as plant fibers directly treated by pycnoporus cinnabarinus are matched with a double-screw extrusion method is rarely reported.

Disclosure of Invention

Aiming at the defects of the prior art, the invention takes waste wood chips in processing industry as raw materials, after the wood chips are biologically treated and softened by NaOH, APMP (alkali Peroxide Mechanical pulping) pulp is prepared by a double screw. The APMP pulp is a super high yield pulp (the yield is more than 80 percent), can simultaneously complete pulping and bleaching processes, and has the main pulping mechanism of the combined action of NaOH and H2O 2. Compared with other methods for preparing chemi-mechanical pulp, the long fiber content of the pulp obtained after double-screw extrusion is obviously reduced. In the research, the pycnoporus cinnabarinus is used for pretreating wood, and then the fiber form and physical properties of the double-screw APMP pulp pretreated by the pycnoporus cinnabarinus are deeply researched; aiming at developing a new idea for the application of biological pulping in the paper industry.

The technical scheme of the invention is as follows:

a method for preparing APMP slurry by double-screw extrusion of microorganism pretreatment; the method comprises the following steps:

(1) preparing materials and sterilizing; (2) pretreating the pycnoporus cinnabarinus; (3) dipping in alkali liquor; (4) thread rolling is carried out on the double screws; (5) bleaching in a first stage; (6) grinding the pulp for the first time at high concentration; (7) bleaching in the second stage; (8) secondary high-concentration grinding; (9) washing pulp, screening pulp and making sheets.

Preferably, according to the present invention, the wood chips used for the preparation in step (1) are selected from one or more of spruce wood chips, red pine wood chips, larch wood chips, masson pine wood chips, poplar wood chips, birch wood chips and linden wood chips.

Preferably, the wood chips in the step (1) are sliced in advance by a chipping machine and then subjected to steaming sterilization treatment; preferably, the length of the sliced wood chips is 3-10 cm; further preferably, the dust removal treatment is performed before the sterilization.

Preferably, the sterilization step in step (1) is: placing the dedusted wood chips in an autoclave for sterilization at the temperature of 120 ℃ and 140 ℃ for 0.5-1.5 h; further preferably, the sterilization temperature is 120 ℃ and the mold time is 0.5 h.

Preferably, the pycnoporus cinnabarinus pretreatment step in the step (2) is as follows: cooling the wood chips obtained in the step (1) under the irradiation of an ultraviolet lamp of a workbench, placing the wood chips into a polyethylene plastic bag after complete cooling, adding cultured pycnoporus cinnabarinus mycelium pellet seed liquid, properly adding a liquid fermentation culture medium, fully and uniformly mixing, and placing the wood chips into a biochemical incubator for culture; the liquid fermentation medium comprises the following components: 1L of potato extract, 15g of glucose, 1.0g of KH2PO4, 0.5g of MgSO 4.7H 2O, 0.01g of CaCl2, 2.5g of asparagine, 0.1g of Na2HPO 4.5H 2O, 0.002g of CuSO 4.5H 2O, 0.001g of FeSO 4.7H 2O and 0.05g of vitamin B1; the culture temperature is 28-32 ℃, the culture humidity is 65-85%, and the culture time is 28-35 d, and further preferably, the culture temperature is 30 ℃, the culture humidity is 70-80%, and the culture time is 28 d; the culture steps of the mycelium pellet of the pycnoporus cinnabarina are as follows: a pycnoporus cinnabarina stored at 4 ℃ on a slant of a solid medium (potato extract 1L, 20g of glucose, 3g of KH2PO4, 1.5g of MgSO4 & 7H2O, vitamin B trace 1, agar 20g) was inoculated into a seed solution medium (the same as the solid medium but without agar) sterilized at high temperature and cultured at 28 ℃ and 180rpm for about 7 days, and a mycelial pellet having a diameter of about 2 to 3mm was grown.

Preferably, the lye impregnation stage of step (3) is: adding the wood chips treated by the microorganisms into 6-10% alkali liquor, and soaking the wood chips in the alkali liquor at the temperature of 45-65 ℃ for 8-12 h; further preferably, the base is sodium hydroxide; further preferably, the concentration of the alkali liquor is 6-8%, the soaking temperature is 45-55 ℃, and the soaking time is 8-10 h; further preferably, the concentration of the alkali liquor is 6%; the feed-liquor ratio of the wood chips to the alkali liquor is 1: 4-1: 6, and preferably 1: 4.

Preferably, the specific steps of step (4) are as follows: and (4) carrying out extrusion thread rolling on the wood chips subjected to the alkali liquor impregnation treatment in the step (3) by using a double-screw thread rolling machine.

Preferably, the first bleaching step of step (5) is: after removing black liquor from the pulp treated by the double screw, adjusting the pH value to about 10.5-11, adding H2O2 and Na2SiO3 at 75-90 ℃, and then reacting for bleaching; the concentration of the H2O2 is 280-350kg/t, preferably 280 kg/t; the concentration of the Na2SiO3 is 35-45kg/t, preferably 35 kg/t; the reaction temperature is preferably 80 ℃; the mass fraction of the added H2O2 and Na2SiO3 in the whole system is 2-4 wt%.

Preferably, the first high consistency refining step in step (6) is: and (4) refining the bleached pulp obtained in the step (5) under the condition of pulp concentration of 25% so that the unreacted H2O2 in the bleaching process participates in reaction.

Preferably, the second stage bleaching step of step (7) is: adding H2O2 into the slurry after the first section of high-concentration grinding for reaction, wherein the concentration of H2O2 is 50-80kg/t, preferably 50 kg/t; the reaction temperature is 80 ℃, and the reaction time is 1 h.

Preferably, the second high consistency refining step in step (8) is: and (4) refining the pulp after the second stage bleaching in the step (7) under the condition of 25% pulp concentration.

Preferably, the process of step (9) is: and washing the pulp obtained by the second high-concentration pulping, screening by using a pulp screening machine, concentrating, measuring the moisture in the pulp, weighing a certain amount of the pulp, scattering by using a fluffer, and carrying out sheet making and drying by using a sheet making machine, wherein the quantitative sheet making is 100g/m 2.

The method for pulping by using the microorganism and the alkali for synergy has the following advantages:

(1) holes and grooves appear in the wood chips treated by the pycnoporus cinnabarinus, resistance encountered by alkali liquor impregnation is reduced, the alkali liquor treatment effect is better, the effect of saving chemicals can be achieved, the pollution to the environment is reduced, and due to the early-stage biological pretreatment, the pulping wastewater is more easily degraded.

(2) After the poplar heartwood is treated by the pycnoporus cinnabarinus, the fiber form after grinding is more beneficial to papermaking; under the condition of the same beating degree, various physical properties of the poplar heartwood pycnoporus cinnabarinus synergistic alkali pretreatment double-screw APMP pulp are superior to those of the alkali pretreatment double-screw APMP pulp only.

Drawings

FIG. 1 is a process flow diagram for preparing APMP slurry by twin-screw extrusion of Pycnoporus cinnabarinus pretreatment;

FIG. 2 shows the growth state of Pycnoporus cinnabarinus on wood chips;

FIG. 3 is a scanning electron microscope picture of poplar before and after treatment with Pycnoporus cinnabarinus.

Detailed Description

Example 1

Cutting poplar core wood into 3-10cm pieces by a chipping machine in advance, removing dust, and then placing the wood pieces subjected to dust removal in an autoclave for sterilization at 120 ℃ for 1h for later use.

Pycnoporus cinnabarinus stored at 4 ℃ on a slant of a solid medium (potato extract 1L, 20g glucose, 3g KH2PO4, 1.5g MgSO4 & 7H2O, vitamin B trace 1, agar 20g) was inoculated into a seed solution medium (the same as the solid medium but without agar) sterilized at a high temperature, and cultured at 28 ℃ and 180rpm for about 7 days to grow into mycelium pellets having a diameter of about 2 to 3 mm.

Taking out sterilized poplar, cooling under the irradiation of an ultraviolet lamp on a workbench, putting the poplar into a polyethylene plastic bag after complete cooling, adding cultured pycnoporus cinnabarinus mycelium pellet seed liquid, properly adding a liquid fermentation culture medium (1L of potato leaching liquid, 15g of glucose, 1.0g of KH2PO4, 0.5g of MgSO 4.7H 2O, 0.01g of CaCl2, 2.5g of asparagine, 0.1g of Na2HPO 4.5H 2O, 0.002g of CuSO 4.5H 2O, 0.001g of FeSO 4.7H 2O and 0.05g of vitamin B1), fully mixing uniformly, and placing the poplar in a biochemical incubator at 30 ℃ for culturing, wherein the humidity is kept between 70 and 80 percent. And regularly observing the growth condition of hypha on the wood chip, and measuring the enzyme activity of laccase secreted by the pycnoporus cinnabarinus during the growth on the wood chip. After the pretreatment of the pycnoporus cinnabarinus for 25 days, the culture is finished, and hyphae on the wood chips are cleaned for standby.

Adding wood chips treated by the pycnoporus cinnabarinus into sodium hydroxide alkaline liquor with the concentration of 6%, and soaking for 8 hours in the alkaline liquor at the temperature of 45 ℃; the feed-liquid ratio of the wood chips to the alkali liquor is 1:4, and the wood chips subjected to alkali liquor impregnation treatment are subjected to extrusion thread rolling by a double-screw thread rolling machine.

After removing black liquor from the pulp treated by the double screw, adjusting the pH value to about 10.5-11, adding 280kg/t of H2O2 and 35kg/t of Na2SiO3 at 75-90 ℃, reacting for 1H, and bleaching, wherein the added H2O2 and Na2SiO3 account for 2-4 wt% of the whole system by mass.

The bleached pulp is subjected to primary refining under the condition of pulp concentration of 25%, so that unreacted H2O2 is reacted in the bleaching process. And adding H2O2 into the slurry after the slurry is ground at a high concentration for reaction, wherein the reaction temperature is 80 ℃, and the reaction time is 1H. The bleached pulp from the second stage was then refined a second time at a pulp consistency of 25%.

And washing the pulp obtained by the second high-concentration pulping, screening by using a pulp screening machine, concentrating, measuring the moisture in the pulp, weighing a certain amount of the pulp, scattering by using a fluffer, and carrying out sheet making and drying by using a sheet making machine, wherein the quantitative sheet making is 100g/m 2.

Comparative example 1

Comparative example 1 differs from example 1 in that the lye impregnation is carried out directly after sterilization without treatment with Pycnoporus cinnabarinus.

Comparative examples 2 to 3

Comparative examples 2 to 3 differ from example 1 in that the direct lye impregnation after sterilization was carried out without treatment with Pycnoporus cinnabarinus and the lye concentrations were 8% and 10%, respectively.

The physical properties of the acceptable pulp samples obtained after the second refining in the above examples and comparative examples were measured by a fiber analyzer before sheet making, and the fiber forms of the pulp samples obtained under different conditions were analyzed, and the results are shown in table 1.

TABLE 1 analysis of the morphology of the APMP pulp fibers of poplar core wood

In general, the length of the fibers can have an effect on their physical strength, and longer fiber lengths can impart greater physical properties to the sheet, particularly a greater effect on tear. As can be seen from Table 1, after the vermilion dense pore treatment, the number average length and the mass average length of the pulp fibers are higher than those before the treatment; the result shows that after the poplar heartwood is treated by virtue of the pycnoporus cinnabarinus and the alkaline hydrogen peroxide, the fiber form of the pulp is beneficial to improving the physical strength and tightness of the finished paper, and the aim of improving the physical properties of the paper is fulfilled.

The sheets of the above examples were subjected to the test, and the results are shown in table 2.

TABLE 2 analysis of physical properties of poplar core APMP pulp pages

As can be seen from Table 2, the paper obtained by the treatment of Pycnoporus cinnabarinus has improved tightness, ring crush index, burst index, tensile strength, tear index and breaking length. The whiteness of the paper sheets is reduced after the treatment of the pycnoporus cinnabarinus, which is probably that hyphae on the wood chips cannot be completely cleaned when the wood chips are washed, and part of bleaching agent H2O2 is consumed by the hyphae remained on the wood chips, so that the whiteness of the paper sheets is reduced; according to the analysis of the fiber morphology of the pulp shown in table 2, the twist index of the fiber is increased, which indicates that the fiber becomes softer, the fiber is not easy to be cut off in the beating process, and the binding force between the fibers of the paper sheet is improved, so that the physical strength of the finished paper, such as tightness, burst index and the like, is improved.

Claims

1. A method for preparing APMP slurry by using double screws for pretreating Pycnoporus cinnabarinus is characterized by comprising the following steps:

(1) preparing materials and sterilizing; (2) pretreating the pycnoporus cinnabarinus; (3) soaking in alkali liquor; (4) thread rolling is carried out on the double screws; (5) bleaching in a first stage; (6) grinding the pulp for the first time at high concentration; (7) bleaching in the second stage; (8) secondary high-concentration grinding; (9) washing, screening and sheet making;

wherein the step (1) comprises: selecting proper wood chips, slicing the wood chips by a chipping machine in advance, and then carrying out steaming sterilization treatment;

the step (2) comprises the following steps: cooling the sterilized wood chips under the irradiation of an ultraviolet lamp of a workbench, putting the wood chips into a polyethylene plastic bag after complete cooling, adding cultured pycnoporus cinnabarinus mycelium pellet seed liquid, properly adding a liquid fermentation culture medium, fully and uniformly mixing, and putting the wood chips into a biochemical incubator for culture;

the step (3) comprises the following steps: adding wood chips treated by the pycnoporus cinnabarinus into 6-10% alkali liquor, and soaking in the alkali liquor at the temperature of 45-65 ℃ for 8-12 h;

the step (4) comprises the following steps: extruding and thread rolling are carried out on the wood chips subjected to the alkali liquor impregnation treatment in the step (3) by a double-screw thread rolling machine;

the bleaching in the steps (5) and (8) is carried out by reaction under the action of hydrogen peroxide and/or Na2SiO 3.

2. The method according to claim 1, wherein the wood chips in step (1) are selected from one or more of spruce wood chips, spruce pine wood chips, abies wood chips, Korean pine wood chips, larch wood chips, masson pine wood chips, poplar wood chips, birch wood chips and linden wood chips.

3. The method of claim 1, wherein the liquid fermentation medium of step (2) has a composition of: 1L of potato extract, 15g of glucose, 1.0g of KH2PO4, 0.5g of MgSO 4.7H 2O, 0.01g of CaCl2, 2.5g of asparagine, 0.1g of Na2HPO 4.5H 2O, 0.002g of CuSO 4.5H 2O, 0.001g of FeSO 4.7H 2O and 0.05g of vitamin B1.

4. The method according to claim 3, wherein the culture conditions in step (2) are: the culture temperature is 28-32 ℃, the culture humidity is 65-85%, and the culture time is 28-35 d.

5. The method of claim 1, wherein the lye impregnation stage of step (3) is: adding the wood chips treated by the microorganisms into alkali liquor with the concentration of 6-10%, and soaking in alkali water at the temperature of 45-65 ℃ for 8-12 h; further preferably, the base is sodium hydroxide; further preferably, the concentration of the alkali liquor is 6-8%, the soaking temperature is 45-55 ℃, and the soaking time is 8-10 h; further preferably, the concentration of the alkali liquor is 6%; the feed-liquor ratio of the wood chips to the alkali liquor is 1: 4-1: 6, and preferably 1: 4.

6. The method of claim 1, wherein the first bleaching step of step (5) is: after removing black liquor from the pulp treated by the double screw, adjusting the pH value to about 10.5-11, adding H2O2 and Na2SiO3 at 75-90 ℃, and then reacting for bleaching; the concentration of the H2O2 is 280-350kg/t, preferably 280 kg/t; the concentration of the Na2SiO3 is 35-45kg/t, preferably 35 kg/t; the reaction temperature is preferably 80 ℃; the mass fraction of the added H2O2 and Na2SiO3 in the whole system is 2-4 wt%.

7. The method according to claim 1, wherein the first high consistency refining step in step (6) is: grinding the bleached pulp obtained in the step (5) under the condition of pulp concentration of 25% to make unreacted H2O2 participate in the reaction in the bleaching process; the second stage bleaching step of the step (7) is as follows: adding H2O2 into the slurry after the first section of high-concentration grinding for reaction, wherein the concentration of H2O2 is 50-80kg/t, preferably 50 kg/t; the reaction temperature is 80 ℃, and the reaction time is 1 h.

8. The method according to claim 1, wherein the second high consistency refining step in step (8) comprises: and (4) refining the pulp after the second stage bleaching in the step (7) under the condition of 25% pulp concentration.

9. The method of claim 1, the process of step (9) being: and washing the pulp obtained by the secondary high-concentration pulping, screening by using a pulp screening machine, concentrating, measuring the moisture in the pulp, weighing a certain amount of pulp, scattering by using a fluffer, and carrying out sheet making and drying by using a sheet making machine, wherein the quantitative sheet making is 100g/m 2.