Methods for processing shredded woody biomass

Abstract

The purpose of this disclosure is to provide a method for processing pulverized wood biomass, which efficiently removes target components such as sugars from the wood biomass to provide pulverized wood biomass with satisfactory anti-mold properties. This disclosure is a method for processing pulverized wood biomass by compressing it to remove moisture, the pulverized wood biomass being obtained as a pulverized product through pulverization. The method includes controlling the temperature of the pulverized product to be above or equal to 25°C and below or equal to 85°C during compression.

Description

Technical Field

[0001] This disclosure generally relates to methods for processing pulverized wood biomass, and more specifically to methods for processing pulverized wood biomass by compressing it to remove moisture and other substances. Background Technology

[0002] Patent Document 1 discloses a pretreatment apparatus for herbaceous biomass. This apparatus is used to pretreat herbaceous biomass before it is used as fuel, gasification feedstock, or carbide feedstock. Furthermore, the apparatus features a single unit comprising a pressing and dehydration device, wherein mechanisms for pressing and dehydrating the herbaceous biomass, adding water to the herbaceous biomass, and further pressing and dehydrating the herbaceous biomass are configured as a single unit.

[0003] However, the pretreatment device for herbal biomass described in Patent Document 1 fails to satisfactorily remove the target component (e.g., sugar) from the herbal biomass in some cases, and the herbal biomass in which the target component is not satisfactorily removed has poor anti-mold properties. Reference List Patent documents

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

[0005] The purpose of this disclosure is to provide a method for processing pulverized wood biomass, which efficiently removes target components such as sugars from the wood biomass to provide pulverized wood biomass with satisfactory anti-mold properties.

[0006] According to one aspect of this disclosure, a method for processing pulverized wood biomass is a method for processing pulverized wood biomass by compressing the pulverized wood biomass to remove moisture, the pulverized wood biomass being obtained as a pulverized product by pulverizing the wood biomass, the method comprising controlling such that the temperature of the pulverized product is above or equal to 25°C and below or equal to 85°C during compression of the pulverized product. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of a rotary shaft press dewatering machine with blades according to an embodiment; Figure 2 This is a schematic diagram of a belt press according to an embodiment; and Figure 3 This is a schematic diagram of a vacuum dehydrator according to an embodiment. Description of implementation methods

[0008] 1. Overview Woody biomass is the biomass of woody materials. Biomass refers to inexhaustible organic resources of biological origin (excluding fossil fuels). Plants used for woody materials are broadly classified into woody plants (so-called trees) and herbaceous plants (so-called grasses), and can be either woody or herbaceous. Specifically, examples of woody biomass include palm trees, cannabaceous plants, bamboo subfamily plants, and grasses. Examples of palm trees include oil palm, sugar palm, coconut palm, date palm, sago palm, acai palm, and fan palm. Examples of cannabaceous plants include kenaf and jute. Examples of grasses include sugarcane (bagasse). Specifically, examples of parts of the oil palm include the oil palm trunk (OPT), empty fruit bunch (EFB), oil palm frond (OPF), and stem.

[0009] Woody biomass can be used as a raw material for, for example, wood-based panels, fuel pellets, and paper pulp. Specifically, woody biomass is pulverized to obtain a pulverized product, which can then be compressed to obtain fuel pellets, or the pulverized product can be compressed to obtain a compressed product, thereby forming wood-based panels. In particular, when palm trees are used as woody biomass, as much sugar and inorganic component as possible must be removed from the pulverized product beforehand. This is because sugar and inorganic components can cause decay, leading to malfunctions in combustion devices or deterioration of the properties of the wood-based panels (e.g., durability, adhesion, and processability).

[0010] Here, sugars include, for example, glucose, xylose, arabinose, galactose, mannose, sucrose, dextran, xylan, galactan, arabinogalactan, and mannan. In addition, inorganic components include, for example, calcium, potassium, magnesium, silicon dioxide, sulfur, sodium, boron, and cesium.

[0011] Meanwhile, the removed target components extracted from lignocellulosic biomass can be used as useful materials. For example, palm trees have a high proportion of sugars compared to other lignocellulosic biomass. The sugars removed from the pulverized product can be used as fuel, for example, through methane fermentation; therefore, it is desirable to extract an even greater amount of sugar. Note that "removed target components" refers to the components removed from lignocellulosic biomass, and may include other components such as starch in addition to sugars and inorganic components.

[0012] Therefore, the inventors conducted in-depth research and thus developed a method for processing pulverized woody biomass.

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

[0014] First, the woody biomass is pulverized to obtain pulverized woody biomass. Then, water can be added to the pulverized woody biomass. Adding water to the pulverized woody biomass increases its water content, causing the target components in the pulverized woody biomass to dissolve into the added water. As used herein, water content is the mass percentage of water relative to the mass of the woody biomass in a moisture-free state (hereinafter referred to as the fully dry state). Water content is calculated using the following formula.

[0015] Water content = (Mass of water content / Mass of fully dried state) × 100 = (Mass of water content before drying - Mass of fully dried state) / Mass of fully dried state × 100 Controlling the water content of the pulverized wood biomass before compression increases the concentration of the target component removed from the water discharged from the pulverized wood biomass during compression (hereinafter also referred to as the compression liquid), and improves the removal efficiency of the target component from the pulverized wood biomass.

[0016] Then, the pulverized wood biomass, or pulverized wood biomass with added water, is fed into the processing unit and compressed. The compression of the pulverized wood biomass allows the compressed liquid to separate from it. Furthermore, the temperature of the pulverized wood biomass during compression is controlled by, for example, heating / cooling with a temperature control device and / or correspondingly changing the parameters of the processing unit (e.g., the supply rate) so that the target component is readily soluble and the starch in the pulverized wood biomass hardly gelatinizes. Note that if the starch in the pulverized wood biomass gelatinizes, the target component is encapsulated in the gelatinized starch, thereby inhibiting the removal of the target component.

[0017] Controlling the temperature of the pulverized wood biomass during compression improves the removal efficiency of the target components in the pulverized wood biomass, and the compressed pulverized wood biomass exhibits satisfactory mold resistance.

[0018] Therefore, this embodiment enables the efficient removal of target components such as sugars from woody biomass to provide pulverized woody biomass with satisfactory anti-mold properties.

[0019] 2. Details (Implementation Method) The method for processing pulverized woody biomass according to this embodiment will now be described. Note that the embodiments described below are merely examples of various embodiments of this disclosure. Furthermore, various modifications can be made to the embodiments described below to achieve the objectives of this disclosure. Moreover, the mechanisms of action in the embodiments can be explained, and these explanations include hypothetical explanations; therefore, this disclosure should not be construed as merely an explanation of the mechanisms of action.

[0020] <Crush> Crushing is the process of turning woody biomass, which is used as raw material, into a crushed product. Examples of crushing methods include, but are not limited to, hammer milling, cutter milling, chipping, and ball milling. Furthermore, the size of the crushed product obtained by crushing is not limited to a specific size.

[0021] <Add water> Adding water is the step of adding water to pulverized wood biomass to increase its water content. Examples of methods for adding water include, but are not particularly limited to, spraying water using an atomizer, sprayer, etc.; sprinkling water from a hose, nozzle, etc.; and immersion in a water tank. Adding water to pulverized wood biomass increases its water content, thereby dissolving the target components into the added water. Furthermore, water can be added not only to the pulverized product obtained by pulverizing wood biomass as raw material, but also to the pulverized wood biomass after compression and discharge from the processing unit.

[0022] To efficiently extract the target components from pulverized wood biomass, it is crucial to bring the pulverized wood biomass into a water-saturated state. As used herein, water saturation refers to a state in which the intracellular spaces and cell walls of the wood biomass are satisfactorily filled with free and bound water. Note that free water is water existing in a liquid state within the intracellular spaces, and bound water is water existing as water molecules chemically bound to fibers, etc., in the cell walls. The water content required to achieve water saturation varies depending on the plant type and / or part. For example, in the case of empty fruit bunches (EFB) of common oil palm, water saturation is achieved when the water content is greater than or equal to 300%, but in the case of oil palm trunks (OPT), a water content greater than or equal to 600% is required. However, when dehydration and compression are performed simultaneously, the volume of pulverized wood biomass during compression is smaller than that of wood biomass under normal conditions. Therefore, even if the water content of the pulverized wood biomass before compression does not reach the water content required to achieve water saturation under normal conditions, water saturation is achieved during compression, and the target components can be satisfactorily removed.

[0023] The water content of the pulverized wood biomass before compression is preferably higher than or equal to 150%, more preferably higher than or equal to 200%, and even more preferably higher than or equal to 250%. In this case, the target components in the pulverized wood biomass can be satisfactorily removed, and therefore, the pulverized wood biomass has satisfactory anti-mold properties. The water content of the pulverized wood biomass before compression is preferably less than or equal to 600%, more preferably less than or equal to 550%, and even more preferably less than or equal to 500%. In this case, the concentration of the target components in the compression fluid does not decrease, and the compression fluid can be used as a raw material for fuel, etc.

[0024] <Compression> Compression involves processing pulverized wood biomass or pulverized wood biomass with added water using a processing device to remove the target components from the pulverized wood biomass along with the contained water, thereby reducing the percentage of the target components contained in the pulverized wood biomass. The processing device preferably uses at least one selected from the group consisting of a bladed rotary shaft press dewatering machine, a belt press, a flatbed press, a roller press, and a vacuum dewatering machine. A bladed rotary shaft press dewatering machine is more preferably used. The bladed rotary shaft press dewatering machine may have only one rotary shaft or may have two or more rotary shafts. Furthermore, the compression of the wood biomass may be performed only once or may be performed two or more times. Additionally, when compression is performed two or more times, the same processing device may be used, or a different processing device may be used each time compression is performed.

[0025] Figure 1 This is a schematic diagram illustrating an example of a bladed rotary shaft press dewatering machine 1 (hereinafter also referred to as dewatering machine 1) according to an embodiment. Dewatering machine 1 includes a supply unit 11, a bladed rotary shaft 12 having a rotating shaft, a screen 13, and a discharge unit 14. Arrow A indicates the conveying direction of the pulverized wood biomass processed by dewatering machine 1. Arrow B indicates the discharge direction of the compressed liquid filtered from screen 13. In the compression process of dewatering machine 1, the pulverized wood biomass is first supplied to the supply unit 11. Then, the compressed liquid is separated from the pulverized wood biomass by the compression of the bladed rotary shaft 12 and screen 13.

[0026] Figure 2This is a schematic diagram illustrating an example of a belt press 3 according to an embodiment. The belt press 3 includes two belts 31 and a plurality of pressure rollers 32. Arrow A indicates the conveying direction of the pulverized wood biomass processed by the belt press 3. Arrow B indicates the discharge direction of the compressed liquid filtered from the belts 31. In the compression process of the belt press 3, the pulverized wood biomass is first fed onto one belt 31. Then, the compressed liquid is separated from the pulverized wood biomass by compression using two belts 31, including the one belt 31 and another belt 31 different from the one belt 31, and pressure rollers 32.

[0027] Figure 3 This is a schematic diagram illustrating an example of a vacuum dehydrator 4 according to an embodiment. The vacuum dehydrator 4 includes a drum 41, a filter cloth 42, a trough 43, a roller 44, a vacuum pump 45, and a filter pump 46. Arrow A indicates the conveying direction of the pulverized wood biomass 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 air discharge path. During compression by the vacuum dehydrator 4, the pulverized wood biomass supplied to the trough 43 is first drawn in by the vacuum pump 45 and adsorbed onto the surface of the filter cloth 42. The pulverized wood biomass is further conveyed by the rotation of the drum 41. During conveying, the pulverized wood biomass is compressed by the suction of the vacuum pump 45, and the compressed liquid, along with air, passes through the filter cloth 42 and is drawn into the drum 41. That is, the suction separates the compressed liquid from the pulverized wood biomass.

[0028] Now, refer to Figure 1 The steps of compression by dehydrator 1 are described in detail.

[0029] <<Supply Department>> The supply section 11 is the part that supplies the pulverized wood biomass to the dewatering machine 1. The configuration located upstream of the supply section 11 is not specifically shown in the figure, but the pulverized wood biomass can be directly supplied to the dewatering machine 1 manually, or it can be supplied to the dewatering machine 1 manually or automatically using a conveying device such as a conveyor, or other processing devices can be installed, and the pulverized wood biomass obtained by pre-compression can be supplied to the dewatering machine 1.

[0030] <Rotating shaft with blades>> The bladed rotating shaft 12 is an assembly that conveys pulverized wood biomass supplied via the supply section 11 to the discharge section 14, as indicated by arrow A. Furthermore, the bladed rotating shaft 12 rotates, and pressing and shearing forces can be applied to the pulverized wood biomass between the bladed rotating shaft 12 and the screen 13; therefore, the bladed rotating shaft 12 is also an assembly for compressing the pulverized wood biomass. The distance between the bladed rotating shaft 12 and the screen 13 is not limited to a specific distance. The shape of the bladed rotating shaft 12 is not limited to a specific shape, but the shape of a cross-section taken along a plane orthogonal to the bladed rotating shaft 12 and parallel to arrow B is, for example, circular. The rotational speed of the bladed rotating shaft 12 is variable and is set accordingly. Furthermore, the rotational speed can also be referred to as the conveying speed of the pulverized wood biomass. The bladed rotating shaft 12 includes blades (not shown). The details of the blades are not limited to specific details. For example, the number, angle, and shape (e.g., helical shape) of the blades, as well as the distance between the blades (pitch), can be changed accordingly. Changing the blade structure can alter various conditions, such as conveying speed, filling factor, pressure, and shear force. Furthermore, the rotating shaft 12 with blades can be configured as follows: Figure 1 As shown, there is a fixed distance between the bladed rotating shaft 12 and the screen 13, or it can have a so-called conical shape, such that the distance between the bladed rotating shaft 12 and the screen 13 is larger on the supply side 11 and decreases towards the discharge side 14. When the bladed rotating shaft 12 has a conical shape, the pressing pressure and shear force increase as the conveying proceeds.

[0031] <<Sieve>> Screen 13 is a component for filtering the compressed liquid discharged from the pulverized wood biomass after being compressed by the bladed rotating shaft 12. The shape of screen 13 is not limited to a specific shape, but the shape of the cross-section taken along a plane orthogonal to the bladed rotating shaft 12 and parallel to arrow B is, for example, circular. The shape of the cross-section of screen 13 is preferably similar to the shape of the cross-section of the bladed rotating shaft 12. Screen 13 is formed, for example, from perforated metal or wedge-shaped wire mesh, but is not limited to these, and has numerous fine pores. The compressed liquid is filtered through these pores and discharged in a downward direction (the direction indicated by arrow B).

[0032] <<Discharge Section>> The discharge section 14 is the part that discharges the pulverized wood biomass, which is compressed and conveyed by the rotating shaft 12 with blades, to the outside of the dewatering machine 1. The discharge section 14 may be provided with a back pressure plate to apply back pressure to the pulverized wood biomass, thereby increasing the residence time, or it may be provided with a cutter to cut the discharged pulverized wood biomass into the desired size.

[0033] Temperature control of woody biomass during compression To improve the removal efficiency of the target component from the pulverized wood biomass, the temperature of the pulverized wood biomass is controlled during compression. The temperature of the pulverized wood biomass is preferably measured immediately before or after the discharge point, at which point the pulverized wood biomass has undergone the longest period of compression and shear force, and the temperature of the pulverized wood biomass can be the highest. The temperature measurement method is not limited to a specific method, but can be measured by installing sensors or thermocouples in the processing device, or by using contact or non-contact thermometers to measure the temperature of the pulverized wood biomass immediately after the discharge point. Furthermore, it is assumed that the temperature of the pulverized wood biomass during compression is the same as the temperature of the moisture (compressed liquid) discharged from the pulverized wood biomass immediately after compression, which is obtained by filtration at the same location through screen 13, belt 31, filter cloth 42, etc. When the dewatering machine 1 is described as an example, the temperature of the compressed liquid obtained from the high-compression section 2 immediately preceding the discharge section 14 is assumed to be the same as the temperature of the pulverized wood biomass discharged via the discharge section 14, and therefore can be used as a substitute for the temperature of the pulverized wood biomass. The compressed liquid whose temperature can be used as a substitute for the temperature of the pulverized wood biomass is one that is preferably obtained at a position (high-compression section 2) within 20% and more preferably within 10% of the length from the discharge section 14 of the rotating shaft 12 with blades to the side end of the supply section 11, and within the time period during which the temperature of the compressed liquid is maintained upon discharge (e.g., within 30 seconds after discharge). Note that this substitution for the temperature of the pulverized wood biomass applies not only to the use of the dewatering machine 1, but also to the use of a belt press 3, a flatbed press, a roller press, and a vacuum dewatering machine 4. In other words, in the above-mentioned processing apparatus, the temperature of the compressed liquid that can be used as a substitute for the temperature of the pulverized wood biomass is the following: it is obtained at a position where the length of the compressed portion of the pulverized wood biomass is preferably within 20%, more preferably within 10%, and is within a time period during which the temperature of the compressed liquid is maintained upon discharge (e.g., within 30 seconds after discharge).

[0034] Methods for controlling the temperature of pulverized wood biomass include, but are not limited to, control via a temperature controller, control of the supply rate of pulverized wood biomass, and control of the conveying speed. In the case of temperature controller control, a heater may be installed for heating, or a cooling medium pipeline may be installed for cooling.

[0035] By controlling the supply rate of pulverized wood biomass, reducing the supply rate decreases the filling rate of the pulverized wood biomass in the processing unit. This reduces the pressing and shearing forces applied to the pulverized wood biomass, thus lowering its temperature. For similar reasons, increasing the supply rate of pulverized wood biomass increases its temperature.

[0036] When the conveyor speed is controlled, decreasing the conveyor speed lowers the temperature of the pulverized wood biomass. Increasing the conveyor speed increases the temperature of the pulverized wood biomass. Taking dewatering machine 1 as an example, when the conveyor speed is controlled by a rotating shaft 12 with blades, decreasing the conveyor speed by the rotating shaft 12 with blades reduces the frictional heat generated during compression by the pulverized wood biomass and the screen 13, and thus lowers the temperature of the pulverized wood biomass. For similar reasons, increasing the conveyor speed by the rotating shaft 12 with blades increases the temperature of the pulverized wood biomass. Note that the control of the conveyor speed applies not only when using dewatering machine 1, but also when using belt press 3, flatbed press, roller press, and vacuum dewatering machine 4.

[0037] Therefore, predetermined lower and upper limits for the temperature of the pulverized wood biomass are determined in advance. If the temperature is below the predetermined lower limit, the pulverized wood biomass is compressed while its temperature is increased by heating it with a heater, increasing the supply rate, or increasing the conveying speed of the pulverized wood biomass. Furthermore, if the temperature is above the predetermined upper limit, the pulverized wood biomass is compressed while its temperature is decreased by cooling it by passing a cooling medium through a cooling medium pipe, reducing the supply rate, or reducing the conveying speed of the pulverized wood biomass.

[0038] The predetermined lower limit value is preferably +5°C, more preferably +10°C, relative to the lower limit value of the temperature of the pulverized wood biomass. Furthermore, the predetermined upper limit value is preferably -5°C, more preferably -10°C, relative to the upper limit value of the temperature of the pulverized wood biomass. For example, when the lower limit value of the temperature of the pulverized wood biomass is 25°C, the predetermined lower limit value is preferably 30°C, more preferably 35°C. Similarly, when the upper limit value of the temperature of the pulverized wood biomass is 85°C, the predetermined upper limit value is preferably 80°C, more preferably 75°C. By setting the predetermined lower and upper limits as described above and controlling the temperature of the pulverized wood biomass with reference to these values, the temperature of the pulverized wood biomass does not exceed or falls below the predetermined temperature described later.

[0039] In contrast, the temperature at which the pulverized wood biomass is supplied is not limited to a specific temperature, as long as it is below the temperature at which the starch in the pulverized wood biomass gelatinizes. The temperature at which the pulverized wood biomass is supplied is preferably in the range of room temperature to 50°C or lower.

[0040] During compression, the temperature of the pulverized wood biomass is higher than or equal to 25°C, preferably higher than or equal to 35°C, and more preferably higher than or equal to 40°C. Under these conditions, the target components in the pulverized wood biomass readily dissolve into the moisture, thus facilitating their removal. Therefore, the percentage of target components in the pulverized wood biomass can be reduced, resulting in satisfactory mold resistance. Alternatively, the temperature of the pulverized wood biomass is lower than or equal to 85°C, preferably lower than or equal to 80°C. Under these conditions, gelatinization of starch materials in the pulverized wood biomass can be inhibited, thus facilitating the dissolution of target components in the pulverized wood biomass into the moisture, and further facilitating their removal. Therefore, the percentage of target components in the pulverized wood biomass can be reduced, resulting in satisfactory mold resistance.

[0041] 3. Plan As can be seen from the above embodiments, this disclosure includes the solutions described below. In the following description, the reference numerals in parentheses are only for clearly showing the correspondence with the embodiments.

[0042] The first approach is a method for processing pulverized wood biomass, which involves compressing the pulverized wood biomass to remove moisture. The pulverized wood biomass is obtained as a pulverized product by pulverizing the wood biomass. The method includes controlling the temperature of the pulverized product to be higher than or equal to 25°C and lower than or equal to 85°C during compression.

[0043] This method allows for the efficient removal of target components, such as sugars, from pulverized wood biomass to obtain pulverized wood biomass with satisfactory anti-mold properties.

[0044] The second approach is a method for processing pulverized wood biomass, referring to the first approach. The second approach includes measuring the temperature of moisture obtained by compressing the pulverized product, and when the moisture temperature is below a predetermined lower limit, compressing the pulverized product while heating it, and when the moisture temperature is above a predetermined upper limit, compressing the pulverized product while cooling it.

[0045] This method allows for more efficient removal of target components, such as sugars, from pulverized wood biomass, resulting in pulverized wood biomass with satisfactory anti-mold properties.

[0046] The third approach is a method for processing pulverized wood biomass, referring to the first or second approach. In the third approach, the pulverized product is compressed by feeding it into at least one processing device selected from the group consisting of a dewatering machine (1), a belt press (3), a flat press, a roller press, and a vacuum dewatering machine (4).

[0047] This method allows for more efficient removal of target components, such as sugars, from pulverized wood biomass, resulting in pulverized wood biomass with satisfactory anti-mold properties.

[0048] The fourth approach is a method for processing pulverized wood biomass, referring to the third approach. The fourth approach includes measuring the temperature of the moisture obtained by compressing the pulverized product, and when the temperature of the moisture is below a predetermined lower limit, conveying and compressing the pulverized product in the processing apparatus at an increased conveying speed, and when the temperature of the moisture is above a predetermined upper limit, conveying and compressing the pulverized product in the processing apparatus at a decreased conveying speed.

[0049] This method allows for more efficient removal of target components, such as sugars, from pulverized wood biomass, resulting in pulverized wood biomass with satisfactory anti-mold properties.

[0050] The fifth approach is a method for processing pulverized wood biomass, referring to the third or fourth approach. The fifth approach includes measuring the temperature of the moisture obtained by compressing the pulverized product, and when the temperature of the moisture is below a predetermined lower limit, increasing the supply of pulverized product to the processing device and compressing it, and when the temperature of the moisture is above a predetermined upper limit, decreasing the supply of pulverized product to the processing device and compressing it.

[0051] This method allows for more efficient removal of target components, such as sugars, from pulverized wood biomass, resulting in pulverized wood biomass with satisfactory anti-mold properties.

[0052] The sixth scheme is a method for processing pulverized woody biomass, referring to any of the first through fifth schemes. In the sixth scheme, the woody biomass includes oil palm.

[0053] This method allows for the effective use of oil palm.

[0054] The seventh scheme is a method for processing pulverized woody biomass, referring to any of the first through sixth schemes. In the seventh scheme, the water content of the pulverized product before compression is greater than or equal to 150% and less than or equal to 600%.

[0055] This method allows for more efficient removal of target components, such as sugars, from pulverized wood biomass, resulting in pulverized wood biomass with satisfactory anti-mold properties. Furthermore, this method increases the concentration of removed target components in the compressed liquid obtained from compressed pulverized wood biomass, and the compressed liquid can be effectively used as a fuel feedstock.

[0056] The eighth method is a method for processing pulverized woody biomass, referring to any of the first to seventh methods. In the eighth method, the steps of adding water to the pulverized product after removing moisture and compressing the pulverized product with added water are repeated at least once.

[0057] This method can produce pulverized wood biomass with satisfactory mold resistance. Example

[0058] The present disclosure will now be described in detail with reference to embodiments. Note that the present disclosure is not limited to the embodiments described below.

[0059] 1. Example 1 The woody biomass used as raw material is obtained by collecting empty fruit bunches (EFB) from oil palm waste and crushing them using a hammer mill to obtain crushed woody biomass as a crushed product. Water is added to the crushed product by spraying it onto the product using a sprayer, so that the water content of the crushed product is 200%. The crushed product with added water at approximately 20°C is then supplied via a supply section 11 to a dewatering machine 1, which serves as a processing device. The dewatering machine 1 includes a bladed rotating shaft 12 with a rotating axis. The crushed product is compressed under conditions where the compression time is 30 seconds and the water content of the crushed product is 80% when discharged from the dewatering machine 1. The compression time, as used herein, is the period from when the crushed product is supplied to the supply section 11 of the dewatering machine 1 until the crushed product is discharged via the discharge section 14. The feeding, compression, and discharge of the crushed product are performed continuously, and the temperature of the compressed liquid obtained from the high compression section 2 immediately preceding the discharge section 14 of the dewatering machine 1 is defined as the temperature of the crushed woody biomass. When the temperature reaches 25°C, the compressed liquid obtained from the high-compression section 2 immediately before the discharge section 14 of the dewatering machine 1, and the pulverized product discharged through the discharge section 14 are used as evaluation samples.

[0060] 2. Examples 2-10, compared with Examples 1-4 Evaluation samples were obtained in a manner similar to that of Example 1, except that the raw materials, the water content of the pulverized wood biomass before compression, and the temperature at which the evaluation samples were collected were changed as shown in Table 1 below.

[0061] 3. Refer to Example 1 The woody biomass used as raw material was obtained by collecting empty fruit bunches (EFB) from oil palm waste and crushing the empty fruit bunches using a hammer mill to obtain crushed woody biomass similar to that in Example 1 as a crushed product, which was then used as an evaluation sample.

[0062] 4. Evaluation Methods (1) Concentration of the target component removed from the compressed fluid For the evaluation sample (which is the compressed liquid obtained from the high-compression section 2 immediately preceding the discharge section 14 of the dehydrator 1), the concentration of sugar, the target component to be removed, in the compressed liquid was measured using a digital refractometer (model "HI 96811") manufactured by HANNA Instruments. The measurement results were classified based on the following evaluation criteria to evaluate the sugar concentration in the compressed liquid.

[0063] <Evaluation Criteria> A: Greater than or equal to 1% Brix B: Less than 1% Brix

[0064] If the concentration is rated as A, it can be said that the sugar concentration in the compressed fluid is satisfactory, and the compressed fluid can be used as a raw material for, for example, fuel.

[0065] (2) The residual concentration of soluble target components contained in the pulverized wood biomass Evaluation samples of pulverized wood biomass were placed in a desiccator set to 105°C and dried to a completely dry state. 20g of water at 80°C was added to 2g of the completely dried evaluation sample, and the sample was placed in a constant temperature and humidity chamber set to 85°C and 85% humidity for 30 minutes to extract the residual target component from the evaluation sample into the water. After 30 minutes, the evaluation sample was removed from the chamber and left at room temperature for 1 hour to cool. After 1 hour, the concentration of sugars, representing the target component, in the water (extracted water) containing the dissolved residual target component was measured using a digital refractometer (model "HI 96811") manufactured by HANNA Instruments. Based on the measurement results, the residual concentration of soluble sugars in the evaluation sample was calculated using the following formula.

[0066] Residual concentration = Concentration of the target component (sugar) removed from the extract water × Mass of the extract water / Mass under completely dried condition The calculation results were classified based on the following evaluation criteria, and the residual sugar concentration in the evaluation samples was evaluated.

[0067] <Evaluation Criteria> A: Less than 4.5% Brix B: Greater than or equal to 4.5% Brix

[0068] If the residual concentration is rated as A, it can be said that the residual sugar concentration in the pulverized wood biomass is low and the sugar removal effect is satisfactory.

[0069] (3) Evaluation of anti-mildew properties Evaluation samples of pulverized wood biomass were placed in a desiccator set at 105°C and dried until completely dry. Following JIS Z 2911, the completely dry samples were placed in a constant temperature and humidity chamber set at 26°C and 96% humidity and left to stand for 5 days. After 5 days, the samples were removed from the chamber and observed using a digital microscope at 200x magnification to determine the presence or absence of mold. The observation results were classified based on the following evaluation criteria, and the mold resistance was evaluated.

[0070] <Evaluation Criteria> A: The area occupied by the mold is less than 1 / 3 of the entire field of view. B: The area occupied by the mold is greater than or equal to 1 / 3 of the entire field of view.

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

[0072] [Table 1]

[0073] As shown in Table 1, it has been confirmed that in Examples 1 to 10, compared with Comparative Examples 1 to 4, the target components can be removed from the pulverized wood biomass more efficiently, and pulverized wood biomass with satisfactory anti-mold properties can be obtained. Note that in Example 5, compared with the other examples, the concentration of the target components in the compression liquid is low, but the target components can be removed from the pulverized wood biomass more efficiently, and pulverized wood biomass with satisfactory anti-mold properties can be obtained. Therefore, it can be said that the object of this disclosure has been achieved. List of reference numerals

[0074] 1. Rotary shaft press dewatering machine with blades 11 Supply Department 12 Rotating shafts with blades 13 sieves 14 Discharge section 2 High compression section

Claims

1. A method for processing pulverized wood biomass, the method comprising compressing the pulverized wood biomass to remove moisture, the pulverized wood biomass being obtained as a pulverized product by pulverizing the wood biomass, the method comprising controlling such that the temperature of the pulverized product is above or equal to 25°C and below or equal to 85°C during compression of the pulverized product.

2. The method of claim 1, further comprising measuring the temperature of the moisture obtained by compressing the pulverized product, wherein... When the temperature of the moisture is below a predetermined lower limit, the pulverized product is compressed while being heated, and When the temperature of the moisture exceeds a predetermined upper limit, the pulverized product is compressed while being cooled.

3. The method of claim 1, wherein The pulverized product is compressed by being fed to at least one processing device selected from the group consisting of a rotary shaft press dewatering machine with blades, a belt press, a flat press, a roller press, and a vacuum dewatering machine.

4. The method of claim 3, further comprising measuring the temperature of the moisture obtained by compressing the pulverized product, wherein, When the temperature of the moisture is below a predetermined lower limit, the pulverized product is conveyed and compressed in the processing device at an increased conveying speed, and When the temperature of the moisture exceeds a predetermined upper limit, the pulverized product is conveyed and compressed in the processing device at a reduced conveying speed.

5. The method of claim 3, further comprising measuring the temperature of the moisture obtained by compressing the pulverized product, wherein, When the temperature of the moisture is below a predetermined lower limit, the increased supply of the pulverized product is fed into the processing device and compressed. When the temperature of the moisture exceeds a predetermined upper limit, the pulverized product is supplied to the processing device in reduced quantities and compressed.

6. The method of claim 1, wherein The woody biomass includes oil palm.

7. The method of claim 1, wherein The pulverized product has a water content of 150% or higher and 600% or lower before compression.

8. The method of claim 1, further comprising repeating the steps of adding water to the dehydrated pulverized product and compressing the water-added pulverized product at least once.

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