Method for processing crushed wood biomass

Abstract

An object of the present disclosure is to provide a method for treating pulverized wood biomass that can efficiently remove components to be removed, such as sugars, from wood biomass and obtain pulverized wood biomass with good mold resistance. The present disclosure relates to a method for treating pulverized wood biomass that pulverizes wood biomass to obtain a pulverized material, and compresses the pulverized material to remove moisture. The temperature of the pulverized material during compression is controlled to be 25°C or higher and 85°C or lower.

Description

[Technical field]

[0001] The present disclosure relates generally 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. [Background technology]

[0002] Patent Document 1 discloses a pretreatment device for herbaceous biomass. This device is a pretreatment device that pretreats herbaceous biomass before it is used as fuel, gasification feedstock, or carbonized feedstock. The device is further characterized by having a compression and dehydration device that is configured in a single device to compress and dehydrate herbaceous biomass, add water thereto, and then compress and dehydrate 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 that herbaceous biomass from which the components to be removed have not been sufficiently removed has insufficient mold resistance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-153790 A Summary of the Invention

[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 having good mold resistance.

[0006] A method for processing pulverized wood biomass material according to one embodiment of the present disclosure is a method for processing pulverized wood biomass material by pulverizing wood biomass to obtain a pulverized material and compressing the pulverized material to remove moisture, and the temperature of the pulverized material when compressed is controlled to be not lower than 25°C and not higher than 85°C. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram of a bladed rotary shaft compressing dehydrator according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram of a belt press according to an embodiment. [Diagram 3] FIG. 3 is a schematic diagram of a vacuum dehydrator according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] 1. Overview Woody biomass is biomass made of wood-based materials. Biomass means a renewable, organic resource derived from a living organism (excluding fossil fuels). Plants used for woody materials are broadly classified into woody plants (so-called trees) and herbaceous plants (so-called grasses), but they may be either woody or herbaceous. Specifically, woody biomass includes, for example, palm plants, hemp, bamboo, and grass plants. Examples of palm plants include oil palm, butter palm, coconut palm, date palm, sago palm, acai, and palm. Examples of hemp include kenaf and jute. Examples of grass plants include sugarcane (bagasse). Parts of the oil palm in particular include the trunk (OPT: Oil Palm Trunk), empty fruit bunch (EFB: Empty Fruit Bunch), leaves (OPF: Oil Palm Fronds), and stems.

[0009] Woody biomass can be used as a raw material for, for example, wood boards, fuel pellets, paper pulp, etc. Specifically, woody biomass can be pulverized to obtain a pulverized material, and the pulverized material can 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 manufacture a woody board. In particular, when using palm plants as woody biomass, it is necessary to remove sugar and inorganic components from the pulverized material as much as possible in advance. This is because sugar and inorganic components may cause decay, cause trouble in combustion equipment, and cause deterioration of properties such as durability, adhesiveness, and workability of wood boards.

[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 removed 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 or the like, so it is desirable to extract as much sugar as possible. Note that the "removed components" refers to the components removed from woody biomass, and may include other components such as starch in addition to sugar and inorganic components.

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

[0013] The method for treating pulverized wood biomass material 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 moisture. Here, the moisture content refers to the ratio of the mass of moisture 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 from the following formula.

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

[0016] Next, the pulverized wood biomass or the pulverized wood biomass with added water is supplied to a processing device and compressed. By compressing the pulverized wood biomass, it is possible to separate the compressed liquid from the pulverized wood biomass. In addition, by appropriately changing the parameters of the processing device, such as heating / cooling by a temperature control device or the supply amount, the temperature of the pulverized wood 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 wood biomass is not easily gelatinized. Note that if the starch in the pulverized wood biomass is gelatinized, the components to be removed are captured in the paste, hindering the removal of the components to be removed.

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

[0018] Therefore, according to this embodiment, it is possible to efficiently remove components to be removed, such as sugars, from wood biomass, and obtain pulverized wood biomass material having good mold resistance.

[0019] 2.Details (Embodiment) Hereinafter, a method for processing pulverized wood biomass according to an embodiment will be described. Note that the following embodiment is merely a part of various embodiments of the present disclosure. In addition, the following embodiment 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 embodiment may be described, the description of the mechanism of action includes a description based on speculation, and the present disclosure is not bound by the description of the mechanism of action.

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

[0021] <Addition of water> Hydration is a process of increasing the moisture content of pulverized woody biomass by adding water to it. 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, the moisture content of the pulverized woody biomass increases, and the components to be removed are dissolved into the added water. Hydration may be performed not only on pulverized woody biomass obtained by pulverizing the raw material woody biomass, but also on pulverized woody biomass that has been compressed and discharged from a processing device.

[0022] In order to efficiently extract the components to be removed from the pulverized wood biomass, it is important to make the pulverized wood biomass saturated with water. Here, the saturated state refers to a state in which the cell cavity and cell walls of the wood biomass are sufficiently filled with free water and bound water. Free water is water that exists in the cell cavity in a liquid state, and bound water is water that is chemically bound to the fibers in the cell wall as water molecules. The moisture content required to become saturated with water varies depending on the type and part of the plant. For example, in the empty fruit bunch (EFB) of a normal oil palm, the moisture content is 300% or more, while the moisture content of the trunk (OPT) is required to be 600% or more. However, when dehydrating while compressing, the volume of the pulverized wood biomass during compression decreases compared to the wood biomass under normal conditions. Therefore, even if the moisture content of the pulverized wood biomass before compression does not reach the moisture content required to become saturated under normal conditions, it becomes saturated with water during compression, and the components to be removed can be sufficiently discharged.

[0023] The moisture content of the pulverized wood 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 wood biomass can be sufficiently removed, and the pulverized wood biomass has good mold resistance. The moisture content of the pulverized wood 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 squeezed liquid does not decrease, and the squeezed liquid can be used as a fuel raw material, etc.

[0024] <Compression> Compression is a process in which a treatment device is used to discharge woody biomass pulverized material or hydrated woody biomass pulverized material together with moisture containing the components to be removed from the woody biomass pulverized material, thereby reducing the content of the components to be removed contained in the woody biomass pulverized material. The treatment device is preferably 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 is more preferably a bladed rotary shaft compression dehydrator. The bladed rotary shaft compression dehydrator may have only one shaft or two or more shafts. Compression may be performed on the woody biomass only once, or may be performed two or more times. Furthermore, when compression is performed two or more times, the same treatment device may be used for each compression, or different treatment devices may be used.

[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. The dehydrator 1 has a supply section 11, a bladed rotary shaft 12 which is a single shaft, a screen 13, and a discharge section 14. Arrow A indicates the transport direction of pulverized wood biomass material processed by the dehydrator 1. Arrow B indicates the discharge direction of compressed liquid filtered through the screen 13. In compression by the dehydrator 1, the pulverized wood biomass material is first supplied to the supply section 11. Next, the compressed liquid is separated from the pulverized wood biomass material by compression by the bladed rotary shaft 12 and the screen 13.

[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 discharge 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 liquid is separated from the pulverized wood biomass material by compression using the two belts 31, the belt 31 being the one and another belt 31 different from the one described above, 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 has a drum 41, a filter cloth 42, a tank 43, a roll 44, a vacuum pump 45, and a filtration pump 46. Arrow A indicates the conveying direction of the pulverized wood biomass material to be treated by the vacuum dehydrator 4. Arrow B indicates the discharge path of the compressed liquid. Arrow C indicates the direction of the suction of the compressed liquid and air into the inside of the drum 41 by the vacuum pump 45. Arrow D indicates the discharge path of the air. In compression by the vacuum dehydrator 4, the pulverized wood biomass material supplied to the tank 43 is first sucked by the vacuum pump 45 and adsorbed to the surface of the filter cloth 42. Furthermore, the pulverized wood biomass material is conveyed by the rotation of the drum 41. The pulverized wood biomass material is compressed by the suction of the vacuum pump 45 during conveyance, and the compressed liquid passes through the filter cloth 42 together with the air and is sucked into the inside of the drum 41. That is, the above suction separates the compressed liquid from the pulverized wood biomass material.

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

[0029] ≪Supply Department≫ The supply unit 11 is a part that supplies pulverized wood biomass material to the inside of the dehydrator 1. Although not particularly shown in the figure before the supply unit 11, the pulverized wood biomass material may be supplied directly by hand, or may be supplied manually or automatically using a transport facility such as a conveyor, or another processing device may be installed to supply pulverized wood biomass material that has been compressed in advance.

[0030] <Rotating shaft with wings> The rotating shaft 12 with blades is a part that conveys the pulverized woody biomass supplied from the supply unit 11 to the discharge unit 14 as shown by the arrow A. Also, the rotating shaft 12 with blades rotates and can apply a squeezing force and a shearing force to the pulverized woody biomass between it and the screen 13, so it is also a part that compresses the pulverized woody biomass. The distance between the rotating shaft 12 with blades and the screen 13 is not particularly limited. The shape of the rotating shaft 12 with blades is not particularly limited, but the cross-sectional shape when cut by a plane orthogonal to the rotating shaft 12 with blades and parallel to the arrow B is, for example, circular. The rotational speed of the rotating shaft 12 with blades can be changed and is set as appropriate. Also, the above rotational speed can also be referred to as the conveyance speed of the pulverized woody biomass. The rotating shaft 12 with blades has blades (not shown). The details of the blades are not particularly limited, and the number, angle, shape such as spiral shape, and the distance (pitch) between the blades can be changed as appropriate. By changing the structure of the blades, various conditions such as the conveyance speed, filling rate, squeezing force, and shearing force can be changed. Also, as shown in FIG. 1, the distance between the rotating shaft 12 with blades and the screen 13 may be constant, or the distance between the supply unit 11 side and the screen 13 may be large, and the distance between the discharge unit 14 side and the screen 13 may become smaller as it approaches the discharge unit 14 side, that is, it may be in a so-called tapered shape. When the rotating shaft 12 with blades is in a tapered shape, the above squeezing force and shearing force increase as the conveyance progresses.

[0031] ≪Screen≫ The screen 13 is a part that filters the squeezing liquid generated from the pulverized woody biomass compressed by the rotating shaft 12 with blades. The shape of the screen 13 is not particularly limited, but the cross-sectional shape when cut by a plane orthogonal to the rotating shaft 12 with blades 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 rotating shaft 12 with blades. The screen 13 is not particularly limited, but is made of, for example, punching metal or wedge wire screen and has innumerable pores. The squeezing liquid is filtered and discharged downward (the direction in which the arrow B points) from these pores.

[0032] ≪Discharge Unit≫ Discharge section 14 is a section where the pulverized wood biomass material, compressed and transported by bladed rotating shaft 12, is discharged to the outside of dehydrator 1. A back pressure plate may be installed in discharge section 14 to apply back pressure to the pulverized wood biomass material and lengthen 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 crushed wood biomass during compression> In order to improve the efficiency of removing the components to be removed from the pulverized wood biomass material, the temperature of the pulverized wood biomass material during compression is controlled. The temperature of the pulverized wood biomass material is preferably measured immediately before or immediately after discharge, when the pulverized wood biomass material is exposed to the longest compression force and shear force and the temperature of the pulverized wood biomass material is likely to be the highest. The method of measuring the temperature is not particularly limited, and may be measured by installing a sensor or a thermocouple in the treatment device, or may be measured using a contact thermometer or a non-contact thermometer for the pulverized wood biomass material immediately after discharge. In addition, the moisture (compressed liquid) discharged from the pulverized wood biomass material during compression and the pulverized wood biomass material immediately after compression that is filtered through the screen 13, belt 31, filter cloth 42, etc. at the same position is considered to be at the same temperature. Taking the dehydrator 1 as an example, the temperature of the compressed liquid obtained by filtration from the high compression section 2 immediately before the discharge section 14 is considered to be the same as the temperature of the pulverized wood biomass material discharged from the discharge section 14, and may therefore be used as a substitute for the temperature of the pulverized wood biomass material. The squeezed liquid that may be used as a substitute for the temperature of the pulverized wood biomass material is obtained at a position (high compression section 2) that is preferably within 20%, more preferably within 10%, of the length from discharge section 14 to the end of supply section 11 of bladed rotating shaft 12 in the direction from discharge section 14 to supply section 11, and is within the time period during which the temperature at the time of discharge is maintained (for example, within 30 seconds). Note that the substitution of the temperature of pulverized wood biomass material is not limited to the use of dehydrator 1, but can also be applied when using belt press 3, plate press, roll press, and vacuum dehydrator 4. That is, in the above-mentioned processing device, the squeezed liquid that may be used as a substitute for the temperature of pulverized wood biomass material is obtained at a position that is preferably within 20%, more preferably within 10%, of the length of the portion where pulverized wood biomass material is compressed, and is within the time period during which the temperature at the time of discharge is maintained (for example, within 30 seconds).

[0034] The method for controlling the temperature of the pulverized wood biomass material is not particularly limited, but may be, for example, control by a temperature regulator, control of the supply amount of pulverized wood biomass material, control of the conveying speed, etc. When controlling by a temperature regulator, a heater may be installed to heat the material, or a refrigerant pipe may be installed to cool the material.

[0035] In controlling the supply amount of pulverized wood biomass material, if the supply amount of pulverized wood biomass material is reduced, the filling rate of the pulverized wood biomass material in the processing device will be reduced. This will reduce the compressing force and shear force applied to the pulverized wood biomass material, lowering the temperature of the pulverized wood biomass material. For the same reason, if the supply amount of pulverized wood biomass material is increased, the temperature of the pulverized wood biomass material will be increased.

[0036] In controlling the conveying speed, slowing down the conveying speed reduces 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 by the bladed rotating shaft 12, slowing down the conveying speed by the bladed rotating shaft 12 reduces the frictional heat generated between the pulverized wood biomass material and the screen 13 during compression, and therefore reduces the temperature of the pulverized wood biomass material. For the same reason, increasing the conveying speed by the bladed rotating shaft 12 increases the temperature of the pulverized wood biomass material. Note that the control of the conveying speed is not limited to when the dehydrator 1 is used, but can also be applied when the belt press 3, the plate press, the roll press, and the vacuum dehydrator 4 are used.

[0037] For this reason, 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 compressed while increasing its temperature by heating it with a heater, increasing the supply amount of the pulverized wood biomass material, or increasing the conveying speed.If the temperature exceeds the predetermined upper limit, the pulverized wood biomass material is compressed while decreasing its temperature by cooling it by flowing a refrigerant through the refrigerant piping, decreasing the supply amount of the pulverized wood biomass material, or slowing down the conveying speed.

[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 limit and upper limit 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 a specified temperature, which will be described later.

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

[0040] The temperature of the pulverized wood biomass 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 wood biomass are more likely to dissolve in water, making it easier to remove the components to be removed. Therefore, the content of the components to be removed contained in the pulverized wood biomass can be reduced, and the pulverized wood biomass has good mold resistance. The temperature of the pulverized wood biomass is 85°C or lower, and preferably 80°C or lower. In this case, gelatinization of starch in the pulverized wood biomass can be suppressed, making it easier for the components to be removed in the pulverized wood biomass to dissolve in water, making it easier to remove the components to be removed. Therefore, the content of the components to be removed contained in the pulverized wood biomass can be reduced, and the pulverized wood biomass has good mold resistance.

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

[0042] The first aspect is a method for processing wood biomass pulverized material, which comprises pulverizing wood biomass to obtain a pulverized material and compressing the pulverized material to remove moisture, and controlling the temperature of the pulverized material during compression to a range of 25°C or higher and 85°C or lower.

[0043] According to this embodiment, it is possible to efficiently remove components to be removed, such as sugars, from the pulverized wood biomass material, thereby obtaining pulverized wood biomass material having good mold resistance.

[0044] The second aspect is a method for treating pulverized wood 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, it is possible to more efficiently remove components to be removed, such as sugars, from the pulverized wood biomass material, thereby obtaining pulverized wood biomass material having good mold resistance.

[0046] The third aspect is a method for treating pulverized wood biomass material 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, it is possible to more efficiently remove components to be removed, such as sugars, from the pulverized wood biomass material, thereby obtaining pulverized wood biomass material having good mold resistance.

[0048] A fourth aspect is a method for treating pulverized wood 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 aspect, components to be removed such as sugars can be more efficiently removed from the pulverized woody biomass, and a pulverized woody biomass having good mold-proof properties can be obtained.

[0050] The fifth aspect is a method for treating pulverized woody biomass based on the third or fourth aspect. In the fifth aspect, the temperature of the moisture obtained by compressing the pulverized material is measured. If the temperature of the moisture is less than a predetermined lower limit value, the supply amount of the pulverized material supplied to the treatment device is increased and compressed. If the temperature of the moisture exceeds a predetermined upper limit value, the supply amount of the pulverized material supplied to the treatment device is decreased and compressed.

[0051] According to this aspect, components to be removed such as sugars can be more efficiently removed from the pulverized woody biomass, and a pulverized woody biomass having good mold-proof properties can be obtained.

[0052] The sixth aspect is a method for treating pulverized woody biomass based on any one of the first to fifth aspects. In the sixth aspect, the woody biomass contains oil palm.

[0053] According to this aspect, effective utilization of oil palm can be achieved.

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

[0055] According to this aspect, components to be removed such as sugars can be more efficiently removed from the pulverized woody biomass, and a pulverized woody biomass having good mold-proof properties can be obtained. Also according to this aspect, the concentration of the components to be removed in the squeezed liquid obtained from the compressed pulverized woody biomass becomes high, and effective utilization as a raw material for fuel or the like can be achieved.

[0056] An eighth aspect is a method for treating pulverized wood 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 to which water has been added are repeated at least once.

[0057] According to this embodiment, it is possible to obtain pulverized wood biomass material having good mold resistance. EXAMPLES

[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 As the raw material woody biomass, empty fruit bunches (EFB) were collected from oil palm waste, and the empty fruit bunches were pulverized in a hammer mill to obtain woody biomass pulverized material. Water was sprayed onto the pulverized material to add water so that the moisture content of the pulverized material was 200%. The pulverized material with added water at about 20°C was then supplied to a dehydrator 1 having a single bladed rotating shaft 12 as a processing device from a supply section 11, and compressed under conditions of a compression time of 30 seconds and a moisture content of the pulverized material at the time of discharge from the dehydrator 1 of 80%. The compression time here refers to the time from when the pulverized material is supplied to the supply section 11 of the dehydrator 1 until it is discharged from the discharge section 14. The supply, compression, and discharge of the pulverized material were continuously performed, and the temperature of the compressed liquid obtained from the high compression section 2 immediately before the discharge section 14 of the dehydrator 1 was taken as the temperature of the pulverized woody biomass. The squeezed liquid obtained from the high compression section 2 immediately prior to the discharge section 14 of the dehydrator 1 when the temperature reached 25° C., and the above-mentioned 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 material 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 woody biomass pulverized material similar to that in Example 1, and this pulverized material was used as the evaluation sample.

[0062] 4. Evaluation Methodology (1) Concentration of the components to be removed in the squeezed liquid The sugar concentration, which is a component to be removed from the squeezed liquid, was measured for an evaluation sample of the squeezed liquid obtained from the high compression section 2 immediately before the discharge section 14 of the dehydrator 1 using a digital refractometer (model number HI 96811) manufactured by HANNA instruments as a 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] If it is A, the sugar concentration in the pressed liquid is good, and it can be used as a fuel raw material, etc.

[0065] (2) Residual concentration of elutable components to be removed in ground wood biomass Each evaluation sample of woody biomass pulverization was dried in a dryer set at 105°C to a completely dry state. 20g of 80°C water was added to 2g of the completely dried evaluation sample, and the sample was left to stand for 30 minutes in a thermo-hygrostat set at a temperature of 85°C and a humidity of 85%, and the remaining components to be removed in the evaluation sample were extracted into the water. After 30 minutes, the evaluation sample was removed from the thermo-hygrostat and left at room temperature for 1 hour and cooled. After 1 hour, the concentration of sugar was measured as the components to be removed in the water (extraction water) into which the remaining components to be removed had been dissolved, using a digital refractometer (model number HI 96811) manufactured by HANNA instruments as a measuring device. From the measurement results, the remaining concentration of soluble sugar in the evaluation sample was calculated using the following formula.

[0066] Residual concentration = concentration of the component to be removed (sugar) in the extracted water × mass of the extracted water / total dry mass 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 concentration of sugar in the ground wood biomass is small, and it can be said that the sugar removal effect is good.

[0069] (3) Antifungal evaluation Each evaluation sample of pulverized wood biomass was dried in a dryer set at 105°C until it was completely dry. The evaluation samples that were now completely dry were placed in a thermo-hygrostat set at a temperature of 26°C and a humidity of 96%, with reference to JIS Z 2911, and left to stand for five days. After five days, the evaluation samples were removed from the thermo-hygrostat and observed at a magnification of 200x using a digital microscope to confirm the presence or absence of microscopic mold growth in the evaluation samples. The observation results were classified according to the following evaluation criteria, and the mold resistance was evaluated.

[0070] <Evaluation criteria> A: The area of ​​mold that has developed is less than 1 / 3 of the total visual field area. B: The area of ​​mold that has grown is more than 1 / 3 of the total visual area.

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

[0072] [Table 1]

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

[0074] 1. Rotating shaft compressor with blades 11 Supply section 12 Bladed shaft 13 Screens 14 Discharge section 2 High compression section

Claims

1. A method for treating pulverized wood biomass, comprising pulverizing wood biomass to obtain a pulverized material, and compressing the pulverized material to remove moisture, comprising: The temperature of the pulverized material when compressing the pulverized material is controlled to be 25° C. or higher and 85° C. or lower. A method for processing crushed wood biomass.

2. Measure the temperature of the moisture obtained by compressing the pulverized material; If the temperature of the moisture is less than a predetermined lower limit, the pulverized material is compressed while being heated; If the temperature of the moisture exceeds a predetermined upper limit, the pulverized material is compressed while being cooled. A method for treating pulverized wood biomass material according to claim 1.

3. The pulverized material is compressed by being supplied to at least one treatment device selected from the group consisting of a bladed rotary shaft compression dehydrator, a belt press, a plate press, a roll press, and a vacuum dehydrator. A method for treating pulverized wood biomass material according to claim 1.

4. Measure the temperature of the moisture obtained by compressing the pulverized material; If the temperature of the moisture is less than a predetermined lower limit, the conveying speed of the pulverized material in the processing device is increased to compress the pulverized material; If the temperature of the moisture exceeds a predetermined upper limit, the conveying speed of the pulverized material in the processing device is slowed down to compress the pulverized material. A method for treating pulverized wood biomass material according to claim 3.

5. Measure the temperature of the moisture obtained by compressing the pulverized material; If the temperature of the moisture is less than a predetermined lower limit, the amount of the pulverized material supplied to the treatment device is increased and compressed; If the temperature of the moisture exceeds a predetermined upper limit, the amount of the pulverized material supplied to the treatment device is reduced and compressed. A method for treating pulverized wood biomass material according to claim 3.

6. The woody biomass comprises oil palm; A method for treating pulverized wood biomass material according to claim 1.

7. The moisture content of the pulverized material before compression is 150% or more and 600% or less. A method for treating pulverized wood biomass material according to claim 1.

8. Repeating the steps of adding water to the pulverized material from which the water has been removed and compressing the pulverized material to which water has been added at least once. A method for treating pulverized wood biomass material according to claim 1.