JP6821168B2 - How to miniaturize plant cellulose - Google Patents

Description

The present invention relates to a method for refining plant cellulose.

In recent years, the movement of recycling and recycling business has become active, and the use of recycled resources has begun to take root. In the resin industry as well, recycling and recycling are becoming more active, but at present, we are trying to improve the physical properties of recycled resins, seeking more sophisticated and usable recycled resins, and aiming to improve quality.
Much research and development has been carried out on the utilization of cellulose, and improvement of modification is being made by mixing and compatibilizing cellulose and resin.
For example, Patent Documents 1 to 5 disclose a method of mixing cellulose with a resin.
Patent Document 1 includes a cutting step of cutting a raw material fiber and a mixing step of kneading and mixing a thermoplastic resin and a cutting fiber, so that a large amount of plant fiber can be contained and injection molding or the like can be provided. We propose a method for producing a thermoplastic resin composition having sufficient fluidity when used in the above.
Patent Document 2 describes a cutting step in which plant fibers are cut fibers having a predetermined length (preferably a fiber length of 20 mm or less), and crushed fibers having a predetermined size (preferably an average fiber length of 0.5 to 6 mm). In addition, by providing a crushing step in which the average fiber diameter is 10 to 60 μm) and a mixing step in which the thermoplastic resin and the crushed fiber are melt-kneaded and mixed, a large amount of plant fiber can be contained and injection is performed. We have proposed a method for producing a thermoplastic resin composition having sufficient fluidity when used for molding or the like.
Patent Document 3 describes a step of mixing a thermoplastic resin (PP, etc.) with a vegetable material (Kenaf, etc.) to obtain a first mixture containing 50 to 95% by mass of the vegetable material, and a thermoplastic resin (Kenafu, etc.). PP, etc.) is mixed with a vegetable material (Kenaf, etc.) to contain 50 to 95% by mass of the vegetable material, the bending elasticity is 50 to 90% of the first mixture, and the bar flow length is the first. Mixing with a step of obtaining a second mixture of 1.1 to 2.5 times as much as the mixture and a third mixing step of obtaining a mixed crushed product of a first crushed product obtained by crushing the first mixture and a second crushed product obtained by crushing the second mixture. A method for producing a thermoplastic composition and a molded product capable of obtaining a molded product having excellent injection properties and excellent mechanical properties while containing a large amount of vegetable material by providing a pelletizing step of pelletizing the crushed product. We are proposing a manufacturing method for.
Patent Document 4 includes a mixing step of kneading a thermoplastic resin and a plant fiber and mixing them to obtain a resin fiber mixture, and a rolling step of rolling the resin fiber mixture to obtain a flat rolled product C1. We have proposed a method for producing a thermoplastic resin composition which can contain a large amount of plant fibers and has sufficient fluidity when used for injection molding or the like.
Patent Document 5 describes a steaming step of steaming a vegetable material (kenaf core), a pelleting step of compacting the steamed vegetable material to obtain a vegetable material pellet, and a vegetable material pellet and a thermoplastic resin (polypropylene and). / Or a thermoplastic resin composition that can be efficiently mixed even if the difference in specific gravity between the vegetable material and the thermoplastic resin is large by providing a kneading step of kneading with (or polylactic acid) to obtain a thermoplastic resin composition in this order. And a manufacturing method of a molded product are proposed.
Patent Document 6 proposes a fiber-reinforced resin composition suitable for producing molded products such as electrical and electronic equipment products by setting the content of kenaf fibers to 10 to 50% by mass.
Patent Document 7 is a biodegradable resin composition which is a thermoplastic resin having crystallinity, and by setting the content of kenaf fibers to 10 to 50% by mass, it is possible to obtain molded products such as electrical and electronic equipment products. We are proposing a fiber reinforced resin composition suitable for production.
Patent Document 8 is a thermoplastic composition containing at least 50% by weight of non-wood fiber as a natural fiber. In particular, when the non-wood fiber is made into kenaf pulp, it is excellent in dimensional stability and disposal characteristics, and has no odor. We are proposing a plastic composition.
By the way, in order to include cellulose in the resin composition, the cellulose to be mixed has a fine shape (micron unit or more) as much as possible, the cellulose at the time of mixing is dispersed as much as possible, and the mixing with the resin melts from the time of mixing. Uniform mixing is required.
Here, as a method for refining cellulose, there are dry type, wet type, and micronization by a chemical.
Patent Document 9 describes a shearing force in a suspension medium under a medium for swelling natural organic fibers, under a concentration condition in which the suspension has thixotropic properties, and in a direction perpendicular to the long axis of the fibers. Suspension can be guided between two rotating desks and ultrafinely defibrated under the conditions of addition of several nanometers (several nm) to tens of nanometers (several tens of nm) in diameter. We are proposing ultra-fine fibers made of. As a specific method, a suspension in which the fibers are dispersed in water or a solution for swelling natural organic fibers is placed in the center between two rotating desks (two desks rotating in opposite directions). Or when the suspension is placed in the center between two desks, one fixed and the other rotating, and the suspension moves outward from the center due to the centrifugal force generated by the rotation of the desk. The long axis direction of is guided to coincide with the direction of centrifugal force.
Patent Document 10 cuts a suspension of fibrous cellulose by passing it through a small-diameter orifice, giving the suspension a high velocity with a pressure difference of at least 3000 pii, and then colliding it to rapidly decelerate. It consists of a step of causing the action and a step of repeating this step so that the suspension of cellulose becomes a substantially stable suspension, and these steps substantially change the starting material of cellulose into a substantially chemical change. We are proposing a method for producing fine fibrous cellulose, which converts cellulose into fine fibrous cellulose without causing the above. Further, in Patent Document 10, a ball mill is used to produce cellulose having a diameter of several tens of microns, the chemical bond of the cellulose is broken by the crushing step by the ball mill, and the cellulose is pulverized by pressurizing it in water. By doing so, fine cellulose having a particle size of 1 micron or less can be obtained, in the case of a cellulose derivative, this is pulverized in liquid nitrogen, and by pulverizing with sound using a ball mill, the cellulose of ultrafine particles can be obtained. It is described to make.
Patent Document 11 describes a fixed grindstone in which a natural fiber material material obtained by mixing 10 to 15 times the amount of water or oil in 1 part by weight of a natural fiber is compounded with a polymer in the upper part and a rotary grindstone in which the same polymer is compounded in the lower part. Are in phase contact with each other on the flat surface of the circumference, and grindstones and grooves that are inclined in opposite directions to the radial direction are sandwiched between the upper and lower surfaces on the inner recessed surface following the flat surface of the circumference. It is supplied to the central part between the fixed grindstone and the rotary grindstone of the grindstone arranged so as to intersect in a shape, and by the centrifugal force accompanying the rotation of the rotary grindstone and the contact between the grinding ridges of the upper and lower grindstones, It is proposed that the above-mentioned fiber material raw material is repeatedly sheared and ground within 10 times to obtain a natural fiber body defibrated to a diameter of 0.9 μm or less from the outer peripheral discharge portion between the grindstones.
In Patent Document 12, a kenaf solution preparation step of dissolving a kenaf-derived polymer in a solvent to prepare a kenaf solution and an electrospinning step of performing electrospinning using an electrospinning solution containing the kenaf solution are performed in this order. Is proposing.
Patent Document 13 describes a first step in which a raw material fibrous substance (for example, cellulose) is dispersed in a medium (for example, water) and treated with a high-pressure homogenizer to obtain a microfifurylated suspension of the fibrous substance. In the second step, the suspension is deflated (for example, filter-press dehydrated) to form a hard cake, and the cake-like material is crushed to a convenient level and moistened with a liquid medium. Despite this, the microfiber material is made into a microfiber material that is not mutually adhesive and can be treated as substantially powders and granules without being blocked even when the packaged materials are stacked. We are proposing to manufacture.
In Patent Document 14, wood chips are hydrophilized at room temperature using a dilute caustic soda aqueous solution, lignin is selectively partially oxidized and modified in dilute nitric acid, and lignin is denatured by using a dilute caustic soda aqueous solution under atmospheric pressure. Proposes to produce pulp.
Patent Document 15 includes an enzyme treatment step of causing an enzyme to act on the bast of a plant in the presence of water, and by including pectinase in the enzyme, plant fibers can be produced from a plant in a simple environment. We are proposing a method for producing plant fibers.
Patent Document 16 is a method for producing a natural fiber, which comprises a letting treatment step of immersing the fiber plant material in a defibrating solution containing a microorganism that decomposes a substance existing between the fibers of the fiber plant material. It is proposed to reduce the peculiar odor generated in the natural fiber after the letting treatment by having a pressure boiling step in which the fiber subjected to the letting treatment is heated in water while being pressurized through the letting treatment step.

Japanese Unexamined Patent Publication No. 2010-275400 Japanese Unexamined Patent Publication No. 2010-241986 Japanese Unexamined Patent Publication No. 2010-30047 Japanese Unexamined Patent Publication No. 2011-5742 Japanese Unexamined Patent Publication No. 2009-96875 Japanese Unexamined Patent Publication No. 2011-63821 Japanese Patent Application Laid-Open No. 2005-105245 Japanese Unexamined Patent Publication No. 2000-219812 Japanese Unexamined Patent Publication No. 2003-155349 Japanese Patent Application Laid-Open No. 56-19921 Japanese Unexamined Patent Publication No. 4-281017 Japanese Unexamined Patent Publication No. 2013-44063 Japanese Unexamined Patent Publication No. 3-152130 JP 2009-167554 Japanese Unexamined Patent Publication No. 2013-91878 Japanese Unexamined Patent Publication No. 2010-47849

As described above, there are dry, wet, and chemical refining methods for refining cellulose, but it is important that pre- and post-processing, storage, and transfer can be performed inexpensively and easily.

An object of the present invention is to provide a method for refining plant cellulose, which can reduce the amount of the chemical solution in the cooking step, shorten the cooking time, and is easy to handle after the cooking step.

The method for micronizing the plant cellulose of the present invention according to claim 1 targets a plant having a cotton-like woody stem, and the plant is either Kenaf (hibiscus cannabinus) or tomato (Solanum lycopersicum) and is carried in. a cleaning process for cleaning the plant, the dehydration step of dehydrating the plant was washed with the washing step, a drying step of drying the plants which had been dehydrated by the dehydration step, the plant was dried at the drying step, the dry A crushing step of crushing the plant to 6 mm to 8 mm by crushing by, a crushing step of crushing the plant crushed by the crushing step to 1 mm to 3 mm by crushing by a dry method, and a crushing step of crushing the plant in the crushing step with caustic soda and sulfide. A cooking step of evaporating using a chemical solution containing sodium as a main component, a solid-liquid separation step of separating a liquid substance from the cellulose cooked in the cooking step, and a washing and dehydrating of the cellulose separated in the solid-liquid separation step. Later, a micronization step of refining with a wet stone mill type crusher, and a bleaching / hydrophobizing step of bleaching and hydrophobicizing the cellulose refined in the miniaturization step with a bleaching agent and a surfactant. A washing and dehydrating step of washing and dehydrating the bleached and hydrophobicized cellulose in the bleaching / hydrophobizing step, a granulation step of pelletizing the cellulose washed and dehydrated in the washing and dehydrating step with a pelletizer, and the granulation step. It is characterized by having a drying step of drying the cellulose pelleted in.
The present invention according to claim 2 is the stone mill type crusher in which the cellulose washed and dehydrated in the washing and dehydrating step is wetted before the granulation step in the method for refining plant cellulose according to claim 1. After the ultra-fine step, the first substance having a specific gravity of 1 or less and the cellulose are stirred with a solvent, and after the mixing and stirring step, mixing is performed. It has a laminated dehydration step of dehydrating the first substance and the cellulose by a laminating method, and is characterized in that the granulation step is performed after the laminated dehydration step.
The present invention according to claim 3 is the stone mill type crusher in which the cellulose washed and dehydrated in the washing and dehydrating step is wetted before the granulation step in the method for refining plant cellulose according to claim 1. After the ultra-fine step, it has a mixing step of mixing a second substance having a specific gravity of more than 1 and the cellulose, and after the mixing step, the granulation step. It is characterized by performing.

According to the present invention, since the kenaf or tomato is appropriately finely divided by two-step dry pulverization before the cooking step, the amount of the chemical solution in the cooking step can be reduced, the cooking time can be shortened, and the kenaf can be shortened. Or, since the tomatoes are not miniaturized, they are easy to handle after the cooking step. Further, according to the present invention, the use of a bleaching agent can prevent the growth of mold, and the use of a surfactant can make kenaf or tomato hydrophobic, so that it can be stored or moved in a state of being dispersed in water. There is no need to do this, and it can be pelletized for storage and transportation.

Process diagram by the method for refining plant cellulose according to an embodiment of the present invention

The method for micronizing plant cellulose according to the first embodiment of the present invention targets a plant having a cotton-like woody stem, and the plant is either Kenaf (hibiscus cannabinus) or tomato (Solanum lycopersicum). 6mm~8mm a cleaning process for cleaning the plant, the dehydration step of dehydrating the washed plant in the washing step, a drying step of drying the dehydrated plant in the dehydration step, the dried plant in the drying step, the crushing by dry A crushing step of crushing the plants , a crushing step of crushing the plants crushed by the crushing step to 1 mm to 3 mm by dry crushing, and a chemical solution containing caustic soda and sodium sulfide as the main components of the crushed plants in the crushing step. The cooking step of steaming, the solid-liquid separation step of separating the liquid matter from the plants steamed in the cooking step, and the cellulose separated in the solid-liquid separation step are finely divided by a wet stone mill type crusher after washing and dehydration. The bleaching / hydrophobicization step of bleaching and hydrophobicizing the bleaching step and the cellulose pulverized in the pulverization step using a bleaching agent and a surfactant, and the bleaching and hydrophobicizing cellulose in the bleaching / hydrophobicizing step are washed. It has a washing and dehydrating step of dehydrating, a granulation step of pelletizing the cellulose washed and dehydrated in the washing and dehydrating step with a pelletizer, and a drying step of drying the pelleted cellulose in the granulation step. According to the present embodiment, since the plant is appropriately refined by two-step dry pulverization before the cooking step, the amount of the chemical solution in the cooking step can be reduced, the cooking time can be shortened, and the plant can be shortened. Since it has not been miniaturized, it is easy to handle after the cooking process. Further, according to the present embodiment, the generation of mold can be prevented by using a bleaching agent, and the hydrophobicity of cellulose can be performed by using a surfactant, so that the cellulose can be stored and moved in a state of being dispersed in water. It does not need to be done and can be pelletized for storage and movement.

In the second embodiment of the present invention, in the method for refining plant cellulose according to the first embodiment, the cellulose washed and dehydrated in the washing and dehydrating step is subjected to a wet stone mill type crusher before the granulation step. An ultrafine step of ultrafine, a mixed stirring step of stirring a first substance having a specific gravity of 1 or less and cellulose with a solvent after the ultrafine step, and a mixed stirring step of mixing the first substance. It has a laminated dehydration step of dehydrating and cellulose by a laminated method, and a granulation step is performed after the laminated dehydration step. According to this embodiment, homogeneity with a first substance having a specific gravity of 1 or less can be achieved.

In the third embodiment of the present invention, in the method for refining plant cellulose according to the first embodiment, the cellulose washed and dehydrated in the washing and dehydrating step is subjected to a wet stone mill type crusher before the granulation step. It has an ultrafine step of ultrafine, and a mixing step of mixing cellulose with a second substance having a specific gravity greater than 1, after the ultrafine step, and a granulation step is performed after the mixing step. .. According to this embodiment, homogeneity with a second substance having a specific gravity greater than 1 can be achieved.

Hereinafter, a method for refining plant cellulose according to an embodiment of the present invention will be described.
FIG. 1 is a process diagram of a method for refining plant cellulose according to an embodiment of the present invention.

The kenaf (scientific name: hibiscus cannabinus and hibiscus sabdariffa, etc.) according to this example is called red hemp, Cuban kenaf, western hemp, taikenaf, mesta, bimuri, ambari hemp, bombay hemp, etc. It is an annual plant with and is a plant classified in the Malvaceae family. In addition to kenaf, annual plants having cotton-like woody stems (vascular bundles) such as tomato (scientific name: Solanum lycopersicum) and sunflower (scientific name: Heliantus annuus) can be used.

From the carry-in step in step 1 shown in FIG. 1 to the solid-liquid separation step in step 9, the kenaf pulping step is performed.
In the carry-in process in step 1, the cut kenaf products that have been cut and rolled into a roll are carried in.

In the cleaning step in step 2, the carried-in roll-shaped kenaf is unpacked and then put into a belt conveyor for cleaning.

A sorting step is performed together with the cleaning step in step 2 or after the cleaning step in step 2 (step 3). In the sorting step in step 3, soil mud and vegetation other than kenaf are removed from the washed kenaf.

After the sorting step in step 3, a dehydration step is performed (step 4). A screw press is used for the dehydration step in step 4. A screw type press is a press that converts the rotary motion of power such as a motor into a reciprocating motion by a screw mechanism. There are a friction type press machine via a friction clutch and a servo type press machine in which the screw mechanism is directly driven by a servomotor, depending on the method of transmitting the rotational movement to the screw mechanism.

After the dehydration step in step 4, a drying step is performed (step 5). A heating drum dryer is used for the drying step in step 5. In a heating type drum dryer, a dried product is attached to the surface of a cylindrical drum, steam or hot water is supplied as a heat medium inside the drum, and the surface film is dried while being in contact with the drum for continuous processing. Can be done. By drying with a heating drum, it is possible to prevent cinnamon bark from remaining during crushing.

After the drying step in step 5, a crushing step is performed (step 6). In the crushing step in step 6, kenaf is crushed to a size of 6 mm to 8 mm with a dry uniaxial crusher. The kenaf is crushed so as to be cut by a rotary blade attached to a rotating rotor and a fixed blade attached to the main body. The crushed kenaf passes through a screen attached to the uniaxial crusher main body and is discharged from the lower part of the main body. Kenaf of a size that cannot pass through the screen is crushed again until it is sized to pass through the screen. In addition, the kenaf is thrown in from above by the hopper and pushed by the pusher to stably continue crushing. The crushing step in step 6 allows the size to be suitable for the crushing step in step 7.

After the crushing step in step 6, a crushing step is performed (step 7). In the crushing step in step 7, the primary crushed product (6 mm to 8 mm) is crushed to a size of 1 mm to 3 mm by a dry hammer mill. The hammer mill is a high-speed rotary crusher that impacts and crushes the supplied particles with a high-speed rotating hammer. There is a swing hammer type hammer. By placing a perforated plate, screen, grit, etc. on the outlet side, the particle size of the crushed product can be controlled as a so-called screen mill.
The finer the particle size of the crushed kenaf, the easier it is to evaporate, but if it is crushed too finely, it is not easy to handle in the subsequent process.

A cooking step is performed after the crushing step in step 7 (step 8). In the cooking step in step 8, kenaf is steamed with a chemical solution containing caustic soda and sodium sulfide as main components. The cooking step is preferably carried out at a high temperature.
The finer the particle size of the kenaf crushed in the crushing step in step 7, the shorter the amount of the chemical solution used for the reaction and the shorter the boiling time.

A solid-liquid separation step is performed after the cooking step in step 8 (step 9). In the solid-liquid separation step in step 9, in order to separate the pulp (cellulose) and the boiling liquid, the pulp is placed in a bag such as hemp and pressed under pressure to squeeze out the resin liquid (commonly known as black liquid) from the pulp. Pulp does not have to be completely dehydrated solid-liquid separation as long as it has a water content of 20 to 30% or less. The pulp from which the resin liquid has been separated is washed again with water and dehydrated to be celluloseized.

From the miniaturization step in step 10 to the drying step in step 18, the cellulose pelletization step is performed.
In the miniaturization step in step 10, the miniaturization process is performed using a wet stone mill type crusher having a high rotation speed. The crusher is preferably a wet type because it cools the heat generated by grinding by rotation. Cellulose is refined to 10 nm to 60 nm by the miniaturization step in step 10.

After the miniaturization step in step 10, a bleaching / watering step is performed (step 11). In the bleaching / watering step in step 11, bleaching is performed using a chlorine-based bleaching agent in order to prevent the growth of fungi on the finely divided cellulose. In addition, a surfactant is used for watering.

After the bleaching / dehydrating step in step 11, a washing / dehydrating step is performed (step 12). In the washing and dehydrating step in step 12, the bleached and dehydrated cellulose is washed and dehydrated.

After the washing and dehydrating step in step 12, an ultrafine step is performed (step 13). In the ultra-miniaturization step in step 13, the ultra-miniaturization process is performed using a wet millstone type crusher. Using a wet stone mill type crusher with a high rotation speed, crushing and dusting work are performed at the same time to make kenaf fibers ultrafine. Cellulose is ultra-miniaturized to 10 nm to 30 nm by the ultra-miniaturization step of step 13.

When the first substance having a specific gravity of 1 or less is mixed, a mixing and stirring step is performed after the ultra-miniaturization step in step 13 (step 14). In the mixing and stirring step in step 14, the first substance having a specific gravity of 1 or less and cellulose are stirred with a solvent. For example, it is mixed and stirred in water. Here, the first substance having a specific gravity of 1 or less is a substance that can be utilized as a new material. For example, there are polypropylene and polyethylene, and by kneading a resin together with cellulose, excellent functions of tensile, impact, and bending bullets can be obtained. It is possible to obtain a resin to have. Further, a resin having a barrier function can be obtained by mixing clay minerals.

After the mixing and stirring step in step 14, a laminating dehydration step is performed (step 15). In the laminated dehydration step in step 15, the mixed first substance and cellulose are dehydrated by the laminated method. Here, in the dehydration by the laminating method, for example, like a paper strainer, the first substance mixed by a frame member with a net or a net and cellulose are strained, and water is drained from the mixture laminated on the net or the net to dehydrate. ..

When a second substance having a specific gravity greater than 1 is mixed, a mixing step is performed after the washing and dehydrating step in step 12, the ultrafinening step in step 13, or the laminated dehydration step in step 15 (step). 16). In the mixing step in step 16, the second substance having a specific gravity greater than 1 and cellulose are mixed using a kneader or a mixer. Here, the second substance having a specific gravity greater than 1 is a substance that can be utilized as a new material. For example, there are carbon, metal, mineral, etc., and when mixing fine copper powder, it is kneaded with cellulose together with resin. A conductive resin having a conductive function can be obtained. Further, when carbon is mixed, a resin having a function of blocking magnetism and magnetic waves can be obtained by kneading the resin together with cellulose.

A granulation step is performed after the laminating and dehydrating step in step 15 or after the mixing step in step 16 (step 17).
In the granulation step in step 17, pelletization with a water content of 20 to 30% is performed with a pelletizer.

After the granulation step in step 17, a drying step is performed (step 18). In the drying step in step 18, drying is performed by vibration or hot air.

As described above, according to this embodiment, since the kenaf is appropriately finely divided by two-step dry pulverization before the cooking step in step 8, the amount of the chemical solution in the cooking step can be reduced and the cooking time can be reduced. It is easy to handle after the cooking process because the kenaf is not miniaturized.
Further, according to this embodiment, the generation of mold can be prevented by using the bleaching agent. In addition, since the hydrophobized cellulose improves dispersion in water, the fibers are smoothly loosened and pulverized in the ultrafinening step, and ultrafineness becomes easy.

The method for refining plant cellulose according to the present invention is suitable for using annual cellulose such as tomato and sunflower.

Claims (3)

For plants with cotton-like woody stems
The plant is either kenaf (hibiscus cannabinus) or tomato (Solanum lycopersicum).
A cleaning process for cleaning the brought-in plants and
A dehydration step of dehydrating the plant washed in the washing step,
A drying step of drying the plant dehydrated in the dehydration step,
A crushing step of crushing the plant dried in the drying step to 6 to 8 mm by crushing by a dry method, and a crushing step.
A crushing step of crushing the plant crushed by the crushing step to 1 to 3 mm by crushing by a dry method, and a crushing step.
A cooking step of cooking the plant crushed in the crushing step with a chemical solution containing caustic soda and sodium sulfide as main components, and a cooking step.
A solid-liquid separation step of separating a liquid substance from the cellulose that has been steamed in the cooking step,
The cellulose separated in the solid-liquid separation step is refined by a wet stone mill type pulverizer after washing and dehydrating, and a miniaturization step.
A bleaching / hydrophobizing step of bleaching / hydrophobicizing the cellulose micronized in the micronization step using a bleaching agent and a surfactant.
A washing and dehydrating step of washing and dehydrating the cellulose bleached and hydrophobized in the bleaching and hydrophobizing step,
A granulation step of pelletizing the cellulose washed and dehydrated in the washing and dehydrating step with a pelletizer,
A method for refining plant cellulose, which comprises a drying step of drying the cellulose pelleted in the granulation step. Before the granulation step, the cellulose washed and dehydrated in the washing and dehydrating step is ultra-fine processed by the stone mill type crusher by a wet method, and an ultra-fine step.
After the ultra-miniaturization step, a mixing stirring step of stirring the first substance having a specific gravity of 1 or less and the cellulose with a solvent, and
After the mixing and stirring step, there is a laminated dehydration step of dehydrating the mixed first substance and the cellulose by a laminating method.
The method for refining plant cellulose according to claim 1, wherein the granulation step is performed after the laminated dehydration step. Before the granulation step, the cellulose washed and dehydrated in the washing and dehydrating step is ultra-fine processed by the stone mill type crusher by a wet method, and an ultra-fine step.
The ultra-miniaturization step is followed by a mixing step of mixing the cellulose with a second substance having a specific gravity greater than 1.
The method for refining plant cellulose according to claim 1, wherein the granulation step is performed after the mixing step.