Woody biomass pulverized product treatment method

Abstract

The present invention addresses the problem of providing a woody biomass pulverized product treatment method with which it is possible to obtain a woody biomass pulverized product having good antifungal properties, by efficiently removing components to be removed such as sugar content from woody biomass. The present disclosure pertains to a woody biomass pulverized product treatment method comprising: obtaining a pulverized product through pulverizing of woody biomass; and compressing the pulverized product to remove moisture. The temperature of the pulverized product when compressing the pulverized product is controlled to 25-85°C.

Description

Method for processing crushed wood biomass

[0001] The present disclosure generally relates to a method for treating pulverized wood biomass, and more particularly to a method for treating pulverized wood biomass by compressing the pulverized wood biomass to remove moisture and the like.

[0002] Patent Document 1 discloses a pretreatment device for herbaceous biomass. This device pretreats herbaceous biomass before it is used as fuel, gasification feedstock, or carbonized material. Furthermore, this device is characterized by a compression and dehydration device that includes means for compressing and dehydrating the herbaceous biomass, adding water, and compressing and dehydrating it again.

[0003] However, the pretreatment device for herbaceous biomass described in Patent Document 1 may not be able to sufficiently remove components to be removed, such as sugars, from the herbaceous biomass, and there is a problem in that herbaceous biomass from which the components to be removed have not been sufficiently removed has insufficient mold resistance.

[0004] JP 2012-153790 A

[0005] The object of the present disclosure is to provide a method for processing pulverized wood biomass that can efficiently remove components to be removed, such as sugars, from wood biomass and produce pulverized wood biomass with good mold resistance.

[0006] A method for processing pulverized wood biomass according to one embodiment of the present disclosure is a method for processing pulverized wood biomass by pulverizing wood biomass to obtain pulverized material and compressing the pulverized material to remove moisture, wherein the temperature of the pulverized material when compressed is controlled to be between 25°C and 85°C.

[0007] Fig. 1 is a schematic diagram of a bladed rotary shaft compressing dehydrator according to an embodiment, Fig. 2 is a schematic diagram of a belt press according to an embodiment, and Fig. 3 is a schematic diagram of a vacuum dehydrator according to an embodiment.

[0008] 1. Overview Woody biomass is biomass made from wood-based materials. Biomass refers to renewable, biologically derived organic resources (excluding fossil fuels). Plants used for woody materials are broadly divided into woody plants (so-called trees) and herbaceous plants (so-called grasses), but they can be either woody or herbaceous. Specifically, woody biomass includes, for example, palm plants, hemp, bamboo, and grass plants. Palm plants include, for example, oil palm, borage palm, coconut palm, date palm, sago palm, acai, and palm. Hemp plants include, for example, kenaf and jute. Grass plants include, for example, sugarcane (bagasse). In particular, oil palm parts include the oil palm trunk (OPT), empty fruit bunch (EFB), oil palm fronds (OPF), and stem.

[0009] Woody biomass can be used as a raw material for, for example, wood boards, fuel pellets, and paper pulp. Specifically, woody biomass can be pulverized to obtain a pulverized material, which can then be compressed to obtain fuel pellets, or the pulverized material can be compressed to obtain a compressed material, and then the compressed material can be used to produce a wood board. In particular, when using palm plants as woody biomass, it is necessary to remove as much sugar and inorganic components as possible from the pulverized material beforehand. This is because sugar and inorganic components may cause decay, cause problems with combustion equipment, or reduce the durability, adhesiveness, processability, and other properties of the wood board.

[0010] Here, the sugar components include glucose, xylose, arabinose, galactose, mannose, sucrose, glucan, xylan, galactan, arabinan, mannan, etc., and the inorganic components include calcium, potassium, magnesium, silica, sulfur, sodium, boron, cesium, etc.

[0011] On the other hand, the components extracted from woody biomass can also be used as useful materials. For example, palm plants have a higher sugar content than other woody biomass. The sugar removed from the crushed material can be used as fuel by methane fermentation, so it is desirable to extract as much sugar as possible. Note that "components to be removed" refers to the components removed from woody biomass, and may include sugars and inorganic components as well as other components such as starch.

[0012] Therefore, as a result of intensive research, the present inventor has developed the following method for treating pulverized wood biomass.

[0013] The method for treating pulverized wood biomass according to this embodiment is as follows.

[0014] First, woody biomass is pulverized to obtain pulverized woody biomass. Next, water may be added to the pulverized woody biomass. By adding water to the pulverized woody biomass, the moisture content of the pulverized woody biomass increases, and the components to be removed in the pulverized woody biomass are dissolved into the added water. Here, moisture content refers to the ratio of the mass of water to the mass of woody biomass in a state that does not contain any moisture (hereinafter referred to as a completely dry state). The moisture content is calculated using the following formula.

[0015] Moisture content = mass of moisture / mass in completely dry state × 100 = (mass before drying - mass in completely dry state) / mass in completely dry state × 100 By controlling the moisture content of the pulverized wood biomass material before compression, the concentration of components to be removed in the water (hereinafter also referred to as squeezed liquid) discharged from the pulverized wood biomass material during compression becomes higher, and the removal efficiency of components to be removed in the pulverized wood biomass material becomes greater.

[0016] Next, the pulverized woody biomass or the hydrated pulverized woody biomass is supplied to a processing device and compressed. Compressing the pulverized woody biomass allows for separation of the compressed liquid from the pulverized woody biomass. Furthermore, by appropriately adjusting processing device parameters such as heating / cooling using a temperature control device and the supply amount, the temperature of the pulverized woody biomass during compression is controlled to a temperature at which the components to be removed are easily eluted and at which the starch in the pulverized woody biomass is not easily gelatinized. If the starch in the pulverized woody biomass gelatinizes, the components to be removed are trapped in the paste, hindering their removal.

[0017] By controlling the temperature of the pulverized wood biomass during compression, the efficiency of removing components to be removed from the pulverized wood biomass increases, and the pulverized wood biomass after compression has good mold resistance.

[0018] Therefore, according to this embodiment, components to be removed, such as sugars, can be efficiently removed from woody biomass, and pulverized woody biomass material having good mold resistance can be obtained.

[0019] 2. Details (Embodiments) The following describes a method for processing pulverized wood biomass according to an embodiment. Note that the following embodiments are merely a portion of the various embodiments of the present disclosure. Furthermore, the following embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Furthermore, although the mechanism of action in the embodiments may be described, this description of the mechanism of action includes an explanation based on speculation, and the present disclosure is not bound by the description of the mechanism of action.

[0020] <Crushing> Crushing is a process of pulverizing the raw material woody biomass. The crushing method is not particularly limited, but examples thereof include a hammer mill, a cutter mill, a chipper, and a ball mill. Furthermore, the size of the crushed material obtained by crushing is not particularly limited.

[0021] <Hydration> Hydration is a process in which water is added to the pulverized woody biomass material to increase its moisture content. The method of hydration is not particularly limited, but examples include spraying water using a sprayer or sprayer, sprinkling water from a hose or nozzle, and immersion in a water tank. By adding water to the pulverized woody biomass material, the moisture content of the pulverized woody biomass material increases, and the components to be removed are eluted into the added water. Hydration may be applied not only to pulverized woody biomass material obtained by pulverizing the raw material woody biomass, but also to pulverized woody biomass material that has been compressed and discharged from a processing device.

[0022] To efficiently extract target components from pulverized woody biomass, it is important to saturate the pulverized woody biomass with water. Here, "saturated" refers to a state in which the cell cavities and cell walls of woody biomass are fully filled with free and bound water. Free water is liquid water present in the cell cavities, while bound water is water chemically bound to fibers within the cell walls as water molecules. The moisture content required for saturation varies depending on the plant species and part. For example, typical oil palm empty fruit bunches (EFBs) reach a saturation state at a moisture content of 300% or higher, while trunks (OPTs) require a moisture content of 600% or higher. However, when dehydrating while compressing, the volume of pulverized woody biomass decreases during compression compared to normal woody biomass. Therefore, even if the moisture content of pulverized woody biomass before compression does not reach the moisture content required for normal saturation, it reaches a saturation state during compression, allowing for sufficient removal of target components.

[0023] The moisture content of the pulverized woody biomass before compression is preferably 150% or more, more preferably 200% or more, and even more preferably 250% or more. In this case, the components to be removed in the pulverized woody biomass can be sufficiently removed, and the pulverized woody biomass has good mold resistance. The moisture content of the pulverized woody biomass before compression is preferably 600% or less, more preferably 550% or less, and even more preferably 500% or less. In this case, the concentration of the components to be removed in the compressed liquid is not reduced, and the compressed liquid can be used as a fuel raw material, etc.

[0024] <Compression> Compression is a process in which pulverized woody biomass or hydrated pulverized woody biomass is subjected to a treatment device to discharge water containing the components to be removed from the pulverized woody biomass, thereby reducing the content of the components to be removed in the pulverized woody biomass. The treatment device preferably comprises at least one treatment device selected from the group consisting of a bladed rotary shaft compression dehydrator, a belt press, a flat plate press, a roll press, and a vacuum dehydrator. The treatment device more preferably comprises a bladed rotary shaft compression dehydrator. The bladed rotary shaft compression dehydrator may have a single shaft or two or more shafts. Compression may be performed on the woody biomass only once, or may be performed two or more times. When compression is performed two or more times, the same treatment device or different treatment devices may be used for each compression.

[0025] 1 is a schematic diagram showing an example of a bladed rotary shaft compression dehydrator 1 (hereinafter also referred to as dehydrator 1) according to an embodiment. Dehydrator 1 has a supply unit 11, a single bladed rotary shaft 12, a screen 13, and a discharge unit 14. Arrow A indicates the transport direction of pulverized woody biomass material processed in dehydrator 1. Arrow B indicates the discharge direction of compressed liquid filtered through screen 13. In compression by dehydrator 1, pulverized woody biomass material is first supplied to supply unit 11. Next, compressed by bladed rotary shaft 12 and screen 13, compressed liquid is separated from the pulverized woody biomass material.

[0026] 2 is a schematic diagram showing an example of a belt press 3 according to an embodiment. The belt press 3 has two belts 31 and multiple pressure rolls 32. Arrow A indicates the conveying direction of the pulverized wood biomass material processed by the belt press 3. Arrow B indicates the discharging direction of the compressed liquid filtered from the belt 31. In compression by the belt press 3, the pulverized wood biomass material is first supplied onto one of the belts 31. Next, the compressed wood biomass material is separated from the pulverized wood biomass material by compression using two belts 31, one of which is the belt 31 and another belt 31, and the pressure rolls 32.

[0027] FIG. 3 is a schematic diagram showing an example of a vacuum dehydrator 4 according to an embodiment. The vacuum dehydrator 4 includes a drum 41, a filter cloth 42, a tank 43, rolls 44, a vacuum pump 45, and a filtration pump 46. Arrow A indicates the transport direction of the pulverized woody biomass material being processed by the vacuum dehydrator 4. Arrow B indicates the discharge path of the compressed liquid. Arrow C indicates the direction in which the vacuum pump 45 draws the compressed liquid and air into the drum 41. Arrow D indicates the discharge path of the air. During compression by the vacuum dehydrator 4, the pulverized woody biomass material supplied to the tank 43 is first sucked by the vacuum pump 45 and adsorbed onto the surface of the filter cloth 42. The pulverized woody biomass material is then transported by the rotation of the drum 41. During transport, the pulverized woody biomass material is compressed by the suction of the vacuum pump 45, and the compressed liquid passes through the filter cloth 42 together with the air and is sucked into the drum 41. That is, the compressed liquid is separated from the pulverized woody biomass material by the above-described suction.

[0028] Here, the compression process by the dehydrator 1 will be described in detail with reference to FIG.

[0029] <<Supply Unit>> The supply unit 11 is a unit that supplies pulverized woody biomass material to the inside of the dehydrator 1. Although not specifically shown in the figure, the supply unit 11 may be supplied directly by hand, or may be supplied manually or automatically using a conveying device such as a conveyor, or another processing device may be installed to supply pulverized woody biomass material that has been compressed in advance.

[0030] <Faneed Rotating Shaft> The bladed rotating shaft 12 is a part that transports the pulverized wood biomass supplied from the supply unit 11 to the discharge unit 14, as indicated by arrow A. The bladed rotating shaft 12 also rotates and can apply a compressing force and a shearing force to the pulverized wood biomass between the bladed rotating shaft 12 and the screen 13, thereby compressing the pulverized wood biomass. The gap between the bladed rotating shaft 12 and the screen 13 is not particularly limited. The shape of the bladed rotating shaft 12 is not particularly limited, but the cross-sectional shape when cut along a plane perpendicular to the bladed rotating shaft 12 and parallel to the arrow B is, for example, circular. The rotation speed of the bladed rotating shaft 12 is variable and can be set as appropriate. The rotation speed can also be referred to as the transport speed of the pulverized wood biomass. The bladed rotating shaft 12 has blades (not shown). The details of the blades are not particularly limited, and the number, angle, shape (e.g., spiral shape), and distance (pitch) between the blades can be changed as appropriate. By changing the structure of the blades, it is possible to change various conditions such as the conveying speed, filling rate, compressing force, and shearing force. Furthermore, the bladed rotating shaft 12 may have a constant gap between itself and the screen 13, as shown in Figure 1, or may have a so-called tapered shape in which the gap between itself and the screen 13 is larger on the supply section 11 side and becomes smaller as it approaches the discharge section 14 side. When the bladed rotating shaft 12 is tapered, the above-mentioned compressing force and shearing force increase as the conveyance progresses.

[0031] <Screen> The screen 13 is a part that filters the compressed liquid produced from the pulverized wood biomass compressed by the bladed rotating shaft 12. The shape of the screen 13 is not particularly limited, but the cross-sectional shape when cut along a plane perpendicular to the bladed rotating shaft 12 and parallel to the arrow B is, for example, circular. The cross-sectional shape of the screen 13 is preferably the same as that of the bladed rotating shaft 12. The screen 13 is not particularly limited, but is made of, for example, punched metal or a wedge wire screen, and has countless pores. The compressed liquid is filtered and discharged downward (in the direction of arrow B) through these pores.

[0032] <Discharge Section> The discharge section 14 is a section where the pulverized wood biomass material, which is compressed and transported by the bladed rotating shaft 12, is discharged to the outside of the dehydrator 1. A back pressure plate may be installed in the discharge section 14 to apply back pressure to the pulverized wood biomass material and increase the residence time, or a cutter may be installed to cut the discharged pulverized wood biomass material to a desired size.

[0033] <Temperature Control of Pulverized Woody Biomass Material During Compression> The temperature of the pulverized woody biomass material during compression is controlled to improve the removal efficiency of components to be removed from the pulverized woody biomass material. The temperature of the pulverized woody biomass material is preferably measured immediately before or immediately after discharge, when the pulverized woody biomass material is exposed to compression and shear forces for the longest period and when the temperature of the pulverized woody biomass material is likely to be highest. The temperature may be measured using a sensor or thermocouple installed in the treatment device, or using a contact or non-contact thermometer on the pulverized woody biomass material immediately after discharge. It is also believed that the water (pressed liquid) discharged from the pulverized woody biomass material immediately after compression, which is filtered through the screen 13, belt 31, filter cloth 42, etc. at the same position, is at the same temperature. Using the dehydrator 1 as an example, the temperature of the compressed liquid obtained by filtration from the high compression section 2 immediately prior to the discharge section 14 is considered to be the same as the temperature of the pulverized wood biomass discharged from the discharge section 14, and therefore may be used as a substitute for the temperature of the pulverized wood biomass. The compressed liquid that may be used as a substitute for the temperature of the pulverized wood biomass is obtained at a position (high compression section 2) along the length from the discharge section 14 to the end of the bladed rotating shaft 12 on the supply section 11 side, preferably within 20%, more preferably within 10%, of the length in the direction from the discharge section 14 to the supply section 11, and is maintained at the same temperature as when it was discharged (for example, within 30 seconds). Note that substitution of the temperature of the pulverized wood biomass is not limited to use of the dehydrator 1, but can also be applied when using the belt press 3, plate press, roll press, and vacuum dehydrator 4. In other words, in the above-mentioned processing device, the compressed liquid that can be used as a substitute for the temperature of the pulverized wood biomass material is obtained at a position preferably within 20%, more preferably within 10%, of the length of the portion of the pulverized wood biomass material that is subjected to compression, and is maintained at the same temperature as when it was discharged for a period of time (for example, within 30 seconds).

[0034] The method for controlling the temperature of the pulverized woody biomass material is not particularly limited, but examples include control using a temperature regulator, control of the supply amount of pulverized woody biomass material, control of the conveying speed, etc. When controlling using a temperature regulator, heating may be performed using a built-in heater, or cooling may be performed using a built-in refrigerant pipe.

[0035] In controlling the supply amount of pulverized wood biomass, if the supply amount of pulverized wood biomass is reduced, the filling rate of the pulverized wood biomass in the processing equipment will decrease. This will reduce the compressive and shear forces acting on the pulverized wood biomass, lowering the temperature of the pulverized wood biomass. For the same reason, if the supply amount of pulverized wood biomass is increased, the temperature of the pulverized wood biomass will increase.

[0036] In controlling the conveying speed, slowing the conveying speed decreases the temperature of the pulverized wood biomass material. Increasing the conveying speed increases the temperature of the pulverized wood biomass material. Taking the dehydrator 1 as an example, in controlling the conveying speed using the bladed rotating shaft 12, slowing the conveying speed using the bladed rotating shaft 12 reduces the frictional heat generated between the pulverized wood biomass material and the screen 13 during compression, thereby decreasing the temperature of the pulverized wood biomass material. For the same reason, increasing the conveying speed using the bladed rotating shaft 12 increases the temperature of the pulverized wood biomass material. Note that conveying speed control is not limited to use with the dehydrator 1, but can also be applied when using the belt press 3, plate press, roll press, and vacuum dehydrator 4.

[0037] Therefore, predetermined lower and upper limits for the temperature of the pulverized wood biomass material are determined, and if the temperature is below the predetermined lower limit, the pulverized wood biomass material is heated with a heater, the supply amount of pulverized wood biomass material is increased, or the conveying speed is increased while being compressed.If the temperature exceeds the predetermined upper limit, the pulverized wood biomass material is cooled by flowing a refrigerant through the refrigerant pipe, the supply amount of pulverized wood biomass material is reduced, or the conveying speed is slowed while being compressed.

[0038] The predetermined lower limit is preferably +5°C, more preferably +10°C, relative to the lower limit of the temperature of the pulverized wood biomass material. The predetermined upper limit is preferably -5°C, more preferably -10°C, relative to the upper limit of the temperature of the pulverized wood biomass material. For example, if the lower limit of the temperature of the pulverized wood biomass material is 25°C, the predetermined lower limit is preferably 30°C, more preferably 35°C. Similarly, if the upper limit of the temperature of the pulverized wood biomass material is 85°C, the predetermined upper limit is preferably 80°C, more preferably 75°C. By setting the predetermined lower and upper limits in this way and controlling the temperature of the pulverized wood biomass material with reference to these, it is possible to prevent the temperature of the pulverized wood biomass material from exceeding or falling below the specified temperature described below.

[0039] On the other hand, the temperature of the pulverized wood biomass material when it is supplied is not particularly limited as long as it is below the temperature at which the starch in the pulverized wood biomass material gelatinizes, but it is preferably within the range of room temperature to 50°C or less.

[0040] The temperature of the pulverized woody biomass material during compression is 25°C or higher, preferably 35°C or higher, and more preferably 40°C or higher. In this case, the components to be removed in the pulverized woody biomass material are more likely to dissolve in water, making the components easier to remove. This makes it possible to reduce the content of the components to be removed in the pulverized woody biomass material, and the pulverized woody biomass material has good anti-fungal properties. The temperature of the pulverized woody biomass material is 85°C or lower, preferably 80°C or lower. In this case, gelatinization of starch in the pulverized woody biomass material can be suppressed, making the components to be removed in water more likely to dissolve in water, making the components easier to remove. This makes it possible to reduce the content of the components to be removed in the pulverized woody biomass material, and the pulverized woody biomass material has good anti-fungal properties.

[0041] 3. Aspects As is clear from the above embodiments, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses only to clarify the correspondence with the embodiments.

[0042] The first aspect is a method for processing wood biomass pulverized material, which involves pulverizing wood biomass to obtain pulverized material and compressing the pulverized material to remove moisture, and the temperature of the pulverized material when compressed is controlled to be between 25°C and 85°C.

[0043] According to this embodiment, components to be removed, such as sugars, can be efficiently removed from the pulverized wood biomass material, and a pulverized wood biomass material having good antifungal properties can be obtained.

[0044] A second aspect is a method for treating pulverized woody biomass material based on the first aspect. In the second aspect, the temperature of the moisture obtained by compressing the pulverized material is measured, and if the temperature of the moisture is below a predetermined lower limit, the pulverized material is compressed while being heated, and if the temperature of the moisture is above a predetermined upper limit, the pulverized material is compressed while being cooled.

[0045] According to this embodiment, components to be removed, such as sugars, can be removed more efficiently from the pulverized wood biomass material, and a pulverized wood biomass material having good antifungal properties can be obtained.

[0046] A third aspect is a method for treating pulverized woody biomass based on the first or second aspect. In the third aspect, the pulverized material is supplied to at least one treatment device selected from the group consisting of a dehydrator (1), a belt press (3), a plate press, a roll press, and a vacuum dehydrator (4) and compressed.

[0047] According to this embodiment, components to be removed, such as sugars, can be removed more efficiently from the pulverized wood biomass material, and a pulverized wood biomass material having good antifungal properties can be obtained.

[0048] A fourth aspect is a method for treating pulverized woody biomass material based on the third aspect. In the fourth aspect, the temperature of the moisture obtained by compressing the pulverized material is measured, and if the temperature of the moisture is below a predetermined lower limit, the conveying speed of the pulverized material in the treatment device is increased to compress the pulverized material, and if the temperature of the moisture is above a predetermined upper limit, the conveying speed of the pulverized material in the treatment device is decreased to compress the pulverized material.

[0049] According to this embodiment, components to be removed, such as sugars, can be removed more efficiently from the pulverized wood biomass material, and a pulverized wood biomass material having good antifungal properties can be obtained.

[0050] A fifth aspect is a method for treating pulverized woody biomass material based on the third or fourth aspect. In the fifth aspect, the temperature of the moisture obtained by compressing the pulverized material is measured, and if the temperature of the moisture is below a predetermined lower limit, the amount of pulverized material supplied to the treatment device is increased and compressed, and if the temperature of the moisture is above a predetermined upper limit, the amount of pulverized material supplied to the treatment device is decreased and compressed.

[0051] According to this embodiment, components to be removed, such as sugars, can be removed more efficiently from the pulverized wood biomass material, and a pulverized wood biomass material having good antifungal properties can be obtained.

[0052] A sixth aspect is a method for treating pulverized woody biomass based on any one of aspects 1 to 5. In the sixth aspect, the woody biomass includes oil palm.

[0053] According to this aspect, it is possible to effectively utilize oil palm.

[0054] A seventh aspect is a method for treating pulverized woody biomass material based on any one of aspects 1 to 6. In the seventh aspect, the moisture content of the pulverized material before compression is 150% or more and 600% or less.

[0055] According to this embodiment, it is possible to more efficiently remove components such as sugars from the pulverized woody biomass, thereby obtaining pulverized woody biomass with good mold resistance. Furthermore, according to this embodiment, the concentration of the components to be removed in the compressed liquid obtained from the compressed pulverized woody biomass is increased, which can be effectively used as a fuel raw material, etc.

[0056] An eighth aspect is a method for treating pulverized woody biomass material based on any one of aspects 1 to 7. In the eighth aspect, the steps of adding water to the pulverized material from which the moisture has been removed and compressing the pulverized material after adding water are repeated at least once.

[0057] According to this embodiment, it is possible to obtain pulverized wood biomass material having good antifungal properties.

[0058] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to the following examples.

[0059] 1. Example 1 Empty fruit bunches (EFB) were collected from oil palm waste as the raw woody biomass. The empty fruit bunches were pulverized using a hammer mill to obtain pulverized woody biomass. Water was sprayed onto the pulverized material to add moisture so that the moisture content of the pulverized material reached 200%. The hydrated pulverized material, which was approximately 20°C, was then supplied to a dehydrator 1 (a processing device) with a single bladed rotating shaft 12 via the supply section 11 and compressed for 30 seconds so that the moisture content of the pulverized material reached 80% upon discharge from the dehydrator 1. The compression time refers to the time from when the pulverized material was supplied to the supply section 11 of the dehydrator 1 until it was discharged from the discharge section 14. The supply, compression, and discharge of the pulverized material were performed continuously, and the temperature of the compressed liquid obtained from the high-compression section 2 immediately prior to the discharge section 14 of the dehydrator 1 was used as the temperature of the pulverized woody biomass. The squeezed liquid obtained from the high compression section 2 immediately before the discharge section 14 of the dehydrator 1 when the temperature reached 25° C. and the pulverized material discharged from the discharge section 14 were used as evaluation samples.

[0060] 2. Examples 2 to 10 and Comparative Examples 1 to 4 Each evaluation sample was obtained in the same manner as in Example 1, except that the raw material, the moisture content of the pulverized wood biomass before compression, and the temperature at which the evaluation sample was taken were changed as shown in Table 1 below.

[0061] 3. Reference Example 1 Empty fruit bunches (EFB) were collected from oil palm waste as the raw material woody biomass, and these empty fruit bunches were pulverized in a hammer mill to obtain a pulverized woody biomass product similar to that in Example 1, which was used as an evaluation sample.

[0062] 4. Evaluation Method (1) Concentration of Components to be Removed in the Squeezed Liquid For evaluation samples of the squeezed liquid obtained from the high compression section 2 immediately prior to the discharge section 14 of the dehydrator 1, the concentration of sugars, as components to be removed in the squeezed liquid, was measured using a digital refractometer, model number "HI 96811," manufactured by HANNA Instruments as the measuring device. The measurement results were classified according to the following evaluation criteria, and the sugar concentration in the squeezed liquid was evaluated.

[0063] <Evaluation Criteria> A: 1% Brix or more B: Less than 1% Brix.

[0064] In the case of A, the sugar concentration in the squeezed liquid is good, and it can be used as a raw material for fuel, etc.

[0065] (2) Residual concentration of elutable components to be removed in woody biomass pulverized material Each evaluation sample of woody biomass pulverized material was dried in a dryer set at 105 ° C to completely dry it. 20 g of water at 80 ° C was added to 2 g of the completely dried evaluation sample, and the mixture was left to stand for 30 minutes in a thermo-hygrostat set at 85 ° C and 85% humidity, to extract the remaining components to be removed from the evaluation sample into the water. After 30 minutes, the evaluation sample was removed from the thermo-hygrostat and left at room temperature for 1 hour to cool. After 1 hour, the concentration of sugars was measured as the components to be removed in the water (extracted water) into which the remaining components to be removed had been eluted, using a HANNA Instruments digital refractometer, model number "HI 96811" as the measuring device. From the measurement results, the remaining concentration of elutable sugars in the evaluation sample was calculated using the following formula:

[0066] Residual concentration = concentration of component to be removed (sugar) in extraction water x mass of extraction water / mass in total dry state The calculation results were classified according to the following evaluation criteria, and the residual sugar concentration in the evaluation sample was evaluated.

[0067] <Evaluation Criteria> A: Less than 4.5% Brix B: 4.5% Brix or more.

[0068] In the case of A, the residual sugar concentration in the pulverized wood biomass material is small, and it can be said that the sugar removal effect is good.

[0069] (3) Antifungal Property Evaluation Evaluation samples of each woody biomass pulverized material were placed in a dryer set at 105°C and dried until completely dry. The completely dried evaluation samples were placed in a thermo-hygrostat set at a temperature of 26°C and a humidity of 96%, in accordance with JIS Z 2911, and allowed to stand for 5 days. After 5 days, the evaluation samples were removed from the thermo-hygrostat and observed at a magnification of 200x using a digital microscope to check for the presence or absence of microscopic mold growth in the evaluation samples. The observation results were classified according to the following evaluation criteria, and antifungal property was evaluated.

[0070] <Evaluation Criteria> A: The area occupied by the mold is less than 1 / 3 of the entire visual area. B: The area occupied by the mold is 1 / 3 or more of the entire visual area.

[0071] If it is A, it can be said that the mold resistance is good.

[0072]

[0073] As shown in Table 1, it was confirmed that in Examples 1 to 10, the components to be removed from the pulverized wood biomass product could be removed more efficiently, and pulverized wood biomass product with good antifungal properties was obtained, compared to Comparative Examples 1 to 4. Note that, although Example 5 resulted in a lower concentration of the components to be removed in the compressed liquid compared to the other Examples, it can be said that the objective of the present disclosure was achieved because the components to be removed were efficiently removed from the pulverized wood biomass product and a pulverized wood biomass product with good antifungal properties was obtained.

[0074] DESCRIPTION OF SYMBOLS 1 Rotating shaft compressor dehydrator with blades 11 Supply section 12 Rotating shaft with blades 13 Screen 14 Discharge section 2 High compression section

Claims

1. A method for treating a pulverized woody biomass, which comprises pulverizing a woody biomass to obtain a pulverized product, and compressing the pulverized product to remove moisture, wherein the temperature of the pulverized product during compression is controlled to be 25°C or higher and 85°C or lower.

2. The method for treating a pulverized woody biomass according to claim 1, wherein the temperature of the moisture obtained by compressing the pulverized product is measured, and if the temperature of the moisture is less than a predetermined lower limit value, the pulverized product is compressed while being heated, and if the temperature of the moisture exceeds a predetermined upper limit value, the pulverized product is compressed while being cooled.

3. The method for treating a pulverized woody biomass according to claim 1, wherein the pulverized product is supplied to at least one treatment device selected from the group consisting of a rotary shaft compression dehydrator with blades, a belt press, a plate press, a roll press, and a vacuum dehydrator and compressed.

4. The method for treating a pulverized woody biomass according to claim 3, wherein the temperature of the moisture obtained by compressing the pulverized product is measured, and if the temperature of the moisture is less than a predetermined lower limit value, the conveyance speed of the pulverized product in the treatment device is increased for compression, and if the temperature of the moisture exceeds a predetermined upper limit value, the conveyance speed of the pulverized product in the treatment device is decreased for compression.

5. The method for treating a pulverized woody biomass according to claim 3, wherein the temperature of the moisture obtained by compressing the pulverized product is measured, and if the temperature of the moisture is less than a predetermined lower limit value, the supply amount of the pulverized product supplied to the treatment device is increased for compression, and if the temperature of the moisture exceeds a predetermined upper limit value, the supply amount of the pulverized product supplied to the treatment device is decreased for compression.

6. The method for treating a pulverized woody biomass according to claim 1, wherein the woody biomass contains coconut.

7. The method for treating a pulverized woody biomass according to claim 1, wherein the moisture content of the pulverized product before compression is 150% or more and 600% or less.

8. The method for treating a pulverized woody biomass according to claim 1, wherein the step of adding water to the pulverized product from which the moisture has been removed and compressing the water-added pulverized product is repeated at least once.

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