Woody bio pellet, and woody bio pellet

Abstract

To generate a high energy woody biogas from high energy semi-carbonized carbonaceous material, by generating high energy semi-carbonized carbonaceous material from woody material of the processing raw material, by generating semi-carbonized carbonaceous material from the wood material of the processing raw material.SOLUTION: A woody bio-material or woody bio-pellet of semi-carbonized carbonaceous material, the main components of which are polymeric cellulose components transformed into low-molecular cellulose components, polymeric lignin components transformed into low-molecular lignin components, and multiple hemicellulose-based monosaccharides coagulated and adhered to these cellulose and lignin components.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to wood biopellets and wood biopellets. [Background technology]

[0002] A known method involves torrefying wood material (also known as wood chips) and turning the resulting torrefied material into wood pellets. The wood material, i.e., wood chips, is fed into a rotary kiln at a constant speed using a fixed-feeder. The temperature inside the kiln during torrefying is 200 to 300°C, and the residence time is approximately 60 minutes. The torrefied material is then stored in a drum at the exit of the rotary kiln.

[0003] "Semi-carbonization," also known as "torrefaction," is a fuel conversion technology that involves heating woody biomass in a low-oxygen environment at 200-300°C to decompose organic matter into substances with a high carbon content. Semi-carbonization is known to increase energy density and improve crushability and water resistance, and some semi-carbonization processing equipment is known to be able to perform drying and semi-carbonization in one machine, thereby increasing the semi-carbonization speed by blowing hot air directly onto the raw material.

[0004] The International Energy Agency (IEA) defines "torrefaction" as "heat treatment carried out at 250 to 320°C in a reduced-oxygen atmosphere."

[0005] The pelletizing equipment used is capable of forming powdered semi-carbide into a cylindrical shape with a diameter of approximately 6 mm.

[0006] Large-scale production facilities of tens of thousands of tons are being constructed mainly for Europe and the US. Japan has abundant forest resources, which make it easy to use them on a small scale, and it can also be used to replace fossil fuels with local resources, contributing to regional revitalization.

[0007] Local resources that can be used on a small scale include forest residues such as thinned wood and wind-fallen trees, as well as construction waste.

[0008] The main components that make up wood are polymers such as cellulose, hemicellulose, and lignin, with hemicellulose accounting for approximately 20% and cellulose and lignin accounting for 80%. When wood is heated, the polymer components are thermally decomposed into lower molecular weight components, and the remainder becomes a carbonized residue. Each of these components decomposes at different temperatures: hemicellulose decomposes at approximately 450-570K (177-297°C), cellulose at 510-670K (237-397°C), and lignin at 550-820K (277-547°C).

[0009] A woody biogasification power generation system is known. The woody biogasification power generation system includes a fixed-bed gasifier, a cyclone, a scrubber, a cooling tower, a filter device, and a gas engine generator. The gas engine generator generates, for example, 80 kW of electricity.

[0010] Patent Document 1 describes that by holding the material for 5 to 90 minutes in a temperature range of 200 to 240°C, where hemicellulose decomposition proceeds slowly, the hemicellulose decomposition products volatilize and diffuse outside the carbonized material before charring. It also describes that the first-stage temperature is preferably 210 to 235°C and the carbonization time is preferably 15 to 60 minutes, and the second-stage carbonization temperature is preferably 250 to 280°C and the carbonization time is preferably 15 to 60 minutes.

[0011] Patent Document 2 describes a subcritical water treatment apparatus in which a reaction vessel used in the subcritical water treatment apparatus has a double structure consisting of an outer vessel and an inner vessel housed inside the outer vessel.

[0012] Patent Document 3 describes a method for producing biomass solid fuel, which includes a step of hydrothermal carbonization of EFB (palm oil residue) at a temperature of 150 to 250°C and a pressure of 0.3 to 4.2 MPa (G).

[0013] Non-Patent Document 1 describes fixed-bed, fluidized-bed, entrained-flow, and rotary kiln-type gasifiers in Table 1, Biomass Gasifier Classification [6], and describes the gasification of wood chips. Non-Patent Document 1 also describes the use of high-temperature gasification temperatures, such as 700 to 1200°C. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Japanese Patent Publication No. 2020-45373 [Patent Document 2] Patent No. 4789595 [Patent Document 3] Patent No. 7252389 [Non-patent literature]

[0015] [Non-Patent Document 1] Journal of the Combustion Society of Japan, Vol. 49, No. 150 (2007) 228-235 Summary of the Invention [Problem to be solved by the invention]

[0016] A wood biogasification system is used to produce semi-carbonized charcoal from wood as a processing raw material, and then gasify the semi-carbonized charcoal in a wood biogasification furnace.The amount of semi-carbonized charcoal produced from wood is reduced, and a high amount of semi-carbonized charcoal with high energy is not obtained compared to the amount of wood as a raw material.

[0017] As mentioned above, Japan has many forest resources, and one local resource that can be used on a small scale is forest residues left in forests. To enable the effective use of forest residues that are dispersed on a small scale, to switch fuel from fossil fuels to forest residues, which are a local resource, and to contribute to the revitalization of local areas through this substitution, an effective method of utilizing forest residues is required.

[0018] In view of the above, the present invention employs a newly discovered method for utilizing a subcritical water reaction treatment device, thereby adopting a "semi-carbonization method" that can be defined in a different form from the conventional "semi-carbonization method" defined by the IEA, and aims to obtain a large amount of semi-carbonized charcoal with higher energy than the amount of raw wood material from the amount of raw wood material, thereby generating a large amount of high-energy wood biogas. [Means for solving the problem]

[0019] The present invention provides Cellulose components obtained by lowering the molecular weight of high molecular cellulose components, lignin components obtained by lowering the molecular weight of high molecular lignin components, and cellulose components and lignin components solidified and fixed to these cellulose components and lignin components. Hemi We propose semi-carbonized wood biomaterial and / or wood biopellets, whose main components are multiple cellulose-based monosaccharides.

[0020] In some literature, wood biopellets are sometimes referred to as wood biomass pellets. [Effects of the Invention]

[0021] According to the present invention, as described above, By performing the subcritical water reaction treatment using hydrolysis, low molecular weight wood biomaterial is produced from the input wood material, and from the subcritical water reaction treated wood biomaterial, semi-carbonized carbonized wood biomaterial can be formed, whose main components are low molecular weight cellulose components, low molecular weight lignin components, and multiple hemicellulose-based monosaccharides that have solidified and adhered to these cellulose components and lignin components.

[0022] When the change in the temperature X and weight loss rate Y of the wood material is expressed as an S-shaped curve on the XY coordinate system, which is divided into three sections: the shoulder of the gradual weight loss line, the part that continues into the sudden weight loss part, the S-shaped weight loss part, and the part where the sudden weight loss ends and the S-shaped curve ends into a gradual weight loss line, At a temperature set at the shoulder of the S-shaped curve, the hemicellulose components that form the woody biomaterial are liquefied and solidified, and multiple hemicellulose-based monosaccharides are fixed to the other components that form the woody biomaterial, namely, low-molecular-weight cellulose components and low-molecular-weight lignin components, forming a woody biomaterial whose main components are low-molecular-weight cellulose components and lignin components to which the multiple hemicellulose-based monosaccharides are fixed, making it possible to semi-carbonize the woody biomaterial whose main components are low-molecular-weight cellulose components and lignin components.

[0023] This semi-carbonization process is carried out at a temperature of 150 to 220°C, which is lower than the temperature range used in conventional semi-carbonization processes, thereby producing semi-carbonized wood that retains 90 to 95% of the heat generated by the wood before the process.

[0024] Furthermore, according to the present invention, woody biogas can be efficiently produced using the highly energy semi-carbonized carbonized material. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a diagram showing an overview of a wood biogas generation system according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram showing the configuration of a subcritical water reaction treatment apparatus according to an embodiment of the present invention. [Figure 3] FIG. 1 is a diagram showing the configuration of another subcritical water reaction treatment apparatus according to an embodiment of the present invention. [Figure 4] The diagram shows the relationship between processing temperature and wood weight change, with X representing the processing temperature and Y representing the weight change of the wood. [Figure 5] A diagram illustrating the fixation of multiple monosaccharides of hemicellulose to the depolymerized cellulose and lignin components that form woody biomaterials, followed by semi-carbonization, on the XY coordinate system. [Figure 6] Micrograph of the product of wood processed according to Figure 5 (1) [Figure 7] Micrograph (2) of the wood product treated according to Figure 5 [Figure 8]Micrographs of the wood products treated according to Figure 5 (3) (4) [Figure 9] FIG. 1 is a diagram illustrating an optimal semi-carbonization process. [Figure 10] Diagram showing produced wood biopellets [Figure 11] A diagram showing the process of producing woody biofuel bodies [Figure 12] Illustration of the gasification process of wood biopellets [Figure 13] An XY-axis coordinate diagram illustrating the area used in the present invention. [Figure 14] FIG. 1 is a diagram showing steps of a wood biogas production method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0027] FIG. 1 is a diagram showing an outline of a wood biogas generation system according to an embodiment of the present invention.

[0028] In FIG. 1, the woody biogas generation system 100 is mainly composed of a biopellet production device 2 and a biogas production device 3 connected to the biopellet production device 2 by a transport means 8 such as a transport vehicle.

[0029] The biopellet production apparatus 2 is composed of a subcritical water reactor 5 and a wood biopellet production apparatus 6, and a superheated steam generator 4 is attached to the biopellet production apparatus 2. Superheated steam is delivered to the subcritical water reactor 5.

[0030] Organic forest residues (hereinafter referred to as forest residues), i.e., wood material (so-called wood chips) to be processed, are collected from forests around the country by any means, crushed, and fed into a subcritical water reactor 5 in the form of crushed wood material (hereinafter referred to as wood material 1). A typical example of wood material is cedar wood. Wood material can also be called wood chips.

[0031] The wood material 1 is semi-carbonized by subcritical water reaction treatment using superheated steam as described below, and a semi-carbonized material, i.e., wood biomaterial, is formed. The subcritical water reactor 5 performs subcritical water reaction treatment on the input wood material 1 to form the wood biomaterial.

[0032] Subcritical water reactions involve rapidly hydrolyzing introduced organic matter and breaking it down into smaller molecules by confining high-temperature, high-pressure water in a pressure vessel. A subcritical water reaction apparatus (also called a subcritical treatment device or subcritical apparatus) is used.

[0033] The woody biomaterial is sent to a woody biopellet production device 6, which produces woody biopellets 7. The woody biopellet production device 6 produces woody biopellets 7 using the woody biomaterial according to a known method.

[0034] The wood biopellets produced are sometimes called torrefaction pellets.

[0035] The woody biopellets 7 are transported by transport means 8, for example a transport vehicle, to a silo 11 of the biogas production device 3 and stored therein.

[0036] The biogas production apparatus 3 is equipped with, along the flow, a silo 11, a superheated steam gasifier 12 (hereinafter referred to as the gasifier 12), a bag filter 13, a buffer tank 14, and a gas engine 15. Although not shown in the figure, a condenser and a cyclone may also be provided.

[0037] A superheated steam generator 16 is attached to the gasifier 12, and a generator 17 is connected to the gas engine 15. A belt conveyor 18 is provided between the silo 11 and the gasifier 12, and a char discharge device 19 is provided below the gasifier 12, through which char 20 is discharged from the gasifier 12 and used as fuel 21 for the superheated steam generator 16.

[0038] A hydrogen concentration detector can be disposed inside the gasification furnace 12 to constantly detect and monitor the hydrogen concentration inside the gasification furnace 12. Any commercially available hydrogen concentration detector can be used.

[0039] The wood biopellets 7 stored in the silo 11 are transported to the gas furnace 12, where they are gasified using superheated steam from the superheated steam generator 16 to produce wood biogas. The wood biogas produced in this process is then subjected to a subcritical water reaction process to become high-energy wood biogas with a high carbon content, as will be described later, due to the characteristics of the wood biopellets formed. The gasifier 12 then produces 22 even more high-energy wood biogas.

[0040] As will be described later, by applying an improved wood gas production method to the formed wood biopellets, in addition to the previously mentioned high energy content, the gas furnace 12 can produce even more highly energetic wood biogas 22.

[0041] The electricity generated by the generator 17 is normally transmitted to a power grid after being adjusted in voltage, current, and frequency using a well-known power transmission device.

[0042] As such, the woody biogas generation system 100 shown in Figure 1 is composed of a first-stage component that generates woody biopellets through subcritical water reaction treatment using the biopellet production device 2, and a second-stage component that generates woody biogas from the highly-energized woody biopellets using the biogas production device 3.

[0043] FIG. 2 is a diagram showing the configuration of a wood biopellet manufacturing apparatus according to an embodiment of the present invention.

[0044] In Fig. 2, the hydrothermal reaction treatment system includes a subcritical water reaction treatment device, and is composed of a treatment material input system, a subcritical water reaction device including a heat source for supplying heat, a hydrothermal reaction residue treatment system, and a control device. A typical hydrothermal reaction treatment system itself has a well-known configuration.

[0045] In this embodiment of the present invention, the subcritical water reaction apparatus 5 includes a pressure vessel (also called a reactor) 101. The pressure vessel 101 is connected to a boiler 102 used as a heat source for supplying steam using an aqueous medium, and is also connected to a processing material input system, a methane recovery system, a hydrothermal reaction treatment system, and a torrefaction treatment system. A control device 105 is provided to control the temperature, pressure, and treatment time inside the pressure vessel.

[0046] The pressure vessel 101 is composed of an outer cylindrical vessel (also called an outer jacket) 111 and an inner cylindrical vessel (also called an inner jacket) 112 arranged on the inner wall of the outer cylindrical vessel 111 with a space therebetween, and an agitator 113 is provided in the space (inner space) 106 within the inner cylindrical vessel.

[0047] The pressure vessel 101 is provided with closure lids 114 and 115 at both ends, and one of the lids 115 is provided with a drive motor 116 on its side. The drive motor 116 is connected to an agitator 113 having rotating blades.

[0048] An outer temperature sensor and an outer pressure sensor 121 are provided to measure the temperature and pressure in the space (outer space) 107 between the outer cylindrical container 111 and the inner cylindrical container 112, an inner temperature sensor and an inner pressure sensor 122 to measure the temperature and pressure in the space (inner space) 106 of the inner cylindrical container 112, and a moisture sensor 123 to measure the moisture in the space of the inner cylindrical container 112. These sensors measure the temperature and pressure in the inner space 106 and the moisture in the inner space 106 of the inner cylindrical container 112, and each measurement value is transmitted as a data signal to the control device 105 via an electronic circuit. These signal data are recorded in the recording means of the control device 105. The measured moisture content is used to set control data for the torrefaction treatment time.

[0049] The pressure vessel 101 is provided with a steam exhaust pipe 118 connected to the inner cylindrical vessel 112, and a discharge control valve 119 is provided on the steam exhaust pipe 118. With this configuration, water vapor in the inner space can be discharged to the outside. The pressure vessel 101 is equipped with an input hopper 125 connected to the inner cylindrical vessel 112, and an outlet having an outlet pipe 126 connected to the inner cylindrical vessel 112. The outlet pipe 126 is provided with an outlet discharge control valve 120. With this configuration, the torrefied material produced by the hydrothermal reaction treatment can be recovered to the outside, i.e., in a torrefied material recovery device.

[0050] The crusher 103 receives the collected raw material 131 to be processed, crushes the raw material 131 to be processed, and feeds the powdered raw material into the feed hopper 125. The feed hopper 125 is provided with a control valve, and the feeding of the raw material 131 to be processed, the subsequent processing, and the temperature adjustment to be adopted are controlled by the control device 105.

[0051] The crushing operation of the crusher 103 is controlled by a control device 105 connected by an electronic circuit.

[0052] The type of raw material 131 to be processed (wood material 1 in FIG. 1) is identified when it is collected. In many cases, the type of raw material to be processed is identified by the raw material processor. By installing a photographing means (not shown) near the input hopper 125, comparing the image with a reference image, and providing a means (not shown) for identifying the type of raw material to be processed, the type of raw material to be processed can be identified automatically. Identification data is input to the control device 105.

[0053] The boiler 102 includes a steam supply line 133 that supplies the generated steam to the pressure vessel 101. A superheated steam generator 140 is provided in the steam supply line 133, and superheats the generated steam and supplies it to the pressure vessel 101.

[0054] The steam supply line 133 branches into a branch line 134 that supplies superheated steam into the space between the outer cylindrical vessel 111 and the inner cylindrical vessel 112, and a branch line 135 that supplies superheated steam into the space inside the inner cylindrical vessel 112, and control valves 136 and 137 are installed on each branch line. The control valves 136 and 137 are connected to the control device 105, and their opening and closing are controlled and adjusted by the control device 105. The superheated steam is supplied to the space between the outer cylindrical vessel 111 and the inner cylindrical vessel 112 and / or the space inside the inner cylindrical vessel 112. By providing the superheated steam generator 140, the internal temperature, i.e., the hydrothermal reaction treatment temperature, can be increased regardless of the pressure inside the inner cylindrical vessel.

[0055] The subcritical water reaction apparatus 5 is composed of a pressure vessel equipped with an inlet for the raw material to be treated, a mechanism for making the hydrothermal reaction uniform, and an outlet for removing the semi-carbonized powder produced after the hydrothermal reaction treatment, a heat source for the hydrothermal reaction treatment and heat treatment, and a control device for controlling the hydrothermal reaction treatment and heat treatment, and produces semi-carbonized material by hydrothermal reaction treatment and heat treatment of wood material.

[0056] The pressure vessel is composed of an outer cylindrical vessel and an inner cylindrical vessel, and the inner space within the inner cylindrical vessel The outer space between the inner cylindrical container and the outer cylindrical container is defined by the inner cylindrical container.

[0057] The control means sets the hydrothermal reaction temperature of the subcritical reaction range of water under a predetermined pressure in the hydrolysis treatment area, and the wood is hydrolyzed in the hydrolysis treatment area to produce a hydrolyzed substance, i.e., semi-carbonized wood as a treatment result.

[0058] For example, water vapor is introduced into the inner space, and a hydrothermal reaction temperature in the subcritical reaction range of water is adopted. A hydrothermal reaction pressure is within 2.5 MPa, typically within 0.3 to 3.5 MPa, and a hydrothermal reaction zone is formed, controlled for an appropriately set hydrothermal reaction treatment time, and wood is hydrolyzed to produce a semi-carbonized powder, which is a powdered hydrolysis treatment substance.

[0059] The introduction of water vapor into the inner space is stopped, and the water vapor in the inner space is discharged to the outside.

[0060] In the drying and semi-carbonization treatment area, a semi-carbonization treatment temperature obtained from the type of raw material to be treated and the calorific value multiple is set under a predetermined pressure, and a semi-carbonized powder material having a predetermined calorific value relative to the calorific value of the wood chips and semi-carbonized using a hydrothermal reaction treatment is produced from the hydrolysis treatment material.

[0061] Within the outer space, a torrefaction zone is formed where the carbonization temperature is within the range of 150-220°C and the treatment time is controlled, and torrefaction pellets are formed from the hydrolysis-treated material through hydrothermal reaction, typically using a high-heat-generating hydrothermal reaction process. The torrefaction pellets are then dried, torrefied, and powdered into a hydrothermal reaction solid, called a torrefaction product. A portion of the torrefaction product may be used for other purposes.

[0062] Wood chips with a moisture content of 35-50% and a calorific value of 3,300 kcal / kg are widely known. A lower calorific value of 3,040 kcal / kg has been reported. In the present invention, when calculating the calorific value multiple, wood chips with a calorific value of 3,300 kcal / kg are used as the reference wood chips. The inventors' analysis also confirmed that semi-carbonized wood chips have a calorific value of 3,300 kcal / kg.

[0063] According to experiments conducted by the inventors, it was confirmed that the provision of a torrefaction pellet forming system makes it possible to produce torrefied wood chips that have a calorific value 1.25 times that of the 3,300 kcal / kg that is inherent in torrefaction. The carbon content of wood chips, which is around 50%, increases to over 60% in the torrefied wood chips after hydrothermal reaction, resulting in a high energy content.

[0064] A semi-carbonized powder treatment region can be formed by controlling the treatment time at a semi-carbonized temperature of 150 to 220°C.

[0065] When the powdery particulate semi-carbonized material is obtained, a hydrothermal reaction-based semi-carbonized pellet can be formed, which is mainly composed of the semi-carbonized material described above and is an aggregate of the powdery particulate semi-carbonized material after hydrothermal reaction semi-carbonization.

[0066] The semi-carbonized powder after the hydrothermal reaction is recovered in a semi-carbonized powder recovery device 141, and harmful substances are rendered harmless and reduced in volume 142.

[0067] And, High calorific value resource: Production of semi-carbonized powder with a calorific value multiple of 1.25, preferably 1.5 or more, for the calorific value of wood chips. - Carbon dioxide, dioxin and odor suppression is achieved.

[0068] In this embodiment, a subcritical water reaction apparatus 5 is used.

[0069] The pressure vessel is composed of an outer cylindrical vessel and an inner cylindrical vessel. The inner space within the cylindrical container and the outer space formed between the inner cylindrical container and the outer cylindrical container are referred to as the inner cylindrical container. Compartmentalized by a cylindrical container, a first heating means for introducing steam into the inner space and directly heating the inner space, and a second heating means for directly heating the outer space and indirectly heating the inner space; a hydrolysis treatment zone in which a hydrothermal reaction by hydrolysis is carried out under a hydrothermal reaction pressure can be formed in the internal space by a first heating means; The internal space is heated by a second heating means under a predetermined pressure to form a hydrolysis treatment area. It is possible to form a drying and semi-carbonizing treatment area.

[0070] Furthermore, a system is configured which includes a subcritical water reactor 5 using a pressure vessel with a double-pipe configuration, a hydrothermal reaction treatment and semi-carbonization powder treatment system 6, and the subcritical water reactor 5, and which uses the subcritical water reactor 5 as a heating means, i.e., a system which uses a heat source such as a boiler.

[0071] FIG. 3 is a diagram showing the configuration of another subcritical water reaction apparatus according to an embodiment of the present invention.

[0072] The configuration of the subcritical water reaction apparatus 5 is substantially the same as the configuration of the subcritical water reaction apparatus shown in FIG.

[0073] 3, a heater 117 is provided in an external space 107, and a heating power supply 102A is provided in parallel with a boiler 102. The heating power supply 102A is connected to a control device 105 via an electric circuit and is controlled to be turned on and off.

[0074] The heater 117 is electrically heated by the supply of electricity from the heating power supply 102A.

[0075] 2 in that the outer space 107 is heated by a heat medium such as a heater 117 instead of steam heat. However, the same applies to the hydrolysis treatment of the material to produce torrefied pellets by hydrothermal reaction, typically dried and torrefied hydrothermal torrefied pellets with a high calorific value.

[0076] Similar to the previous example, water vapor is introduced into the inner space to form a low-temperature hydrolysis treatment area in which the temperature is controlled to the subcritical reaction range of water and the hydrothermal reaction pressure is within 3.5 MPa, typically within 2.5 MPa, and the hydrothermal reaction time is appropriately set, and the wood is hydrolyzed to form a powdered hydrolysis-treated substance called semi-carbonized material. However, the difference is that a low-temperature drying and semi-carbonization treatment area in the outer space, in which the semi-carbonization temperature is above the hydrothermal reaction temperature but within 220°C, and the treatment time is controlled, is electrically heated and formed by heater 117 supplied with electricity from heating power source 102A.

[0077] FIG. 4 is a diagram showing the relationship between temperature X and weight loss rate Y on an XY coordinate system when the wood material is carbonized.

[0078] This figure shows the relationship between the processing temperature X and the weight change Y of the wood, with the XY coordinate system representing the processing temperature X and the weight change Y of the wood. When the wood is carbonized, the relationship between the temperature X and the weight loss rate Y is expressed as an S-shaped curve on the XY coordinate system, which can be divided into three sections: the shoulder of the gradual weight loss line that continues into the sudden weight loss, the S-shaped weight loss portion, and the end of the gradual weight loss line at the end of the S-shaped curve.

[0079] When wood, or woody material, is heat-treated (dry-distilled) in an air-deprived state, its weight change is known to follow a course similar to the curve of the processing temperature and weight change of the woody material, the so-called pyrolysis curve (dry-distillation curve), shown in Figure 4. Here, the horizontal axis is the heating temperature, or processing temperature, and the vertical axis is the weight percentage of the remaining solid (residual carbon) relative to the original woody material. The decrease in residual carbon content occurs most rapidly around 250°C, and continues to decrease slowly even at temperatures above 400°C, eventually resulting in a carbonized product of about 1 / 3 to 1 / 4 the weight of the original woody material. Here, the shoulder of the gradual weight loss line that continues to the part where the weight suddenly decreases is called region (1), the part of the S-curve where the weight suddenly decreases is called region (2), and the part of the gradual weight loss line that ends at the S-curve is called region (3).

[0080] The International Energy Agency (IEA) defines "torrefaction" as "heat treatment carried out at 250 to 320°C in a reduced-oxygen atmosphere," and traditionally, semi-carbide formation was carried out at temperatures in the (2) region.

[0081] Figure 5 is a diagram illustrating the coagulation, fixation, and semi-carbonization process of multiple hemicellulose-based monosaccharides into the lower molecular weight cellulose and lignin components that form woody biomaterials, on an XY coordinate system.

[0082] The low-temperature semi-carbonization treatment associated with the subcritical water reaction treatment will now be described.

[0083] Low-temperature semi-carbonization is performed in the (1) region. Semi-carbonization in the (1) region is possible by performing subcritical water reaction treatment.

[0084] In FIG. 5, in process (1), a hydrolysis process (subcritical water reaction process) is carried out using superheated steam to break down wood into smaller molecules.

[0085] The temperature used is the subcritical water reaction temperature, preferably 230 to 240°C, but is not limited to this temperature.

[0086] In process (2), the wood is semi-carbonized at low temperatures.

[0087] By going from process (1) to process (2), semi-carbonization is performed at a low temperature.

[0088] 1st stage: Temperature treatment at 150-220℃ In order to liquefy the hemicellulose components in the wood, the wood is heated to this temperature and maintained at this temperature. Multiple monosaccharides of the liquefied hemicellulose system are produced and exist between the degraded cellulose components and the degraded lignin components.

[0089] Second stage: Temperature treatment at 110-130℃ By lowering the temperature to this level, the liquefied hemicellulose-based monosaccharides are solidified and adhere to the low-molecular-weight cellulose and lignin components.

[0090] These two processes result in semi-carbonized woody bio-wood.

[0091] Semi-carbonized wood biomaterial: Its main components are low molecular weight cellulose components, low molecular weight lignin components, and multiple hemicellulose-based monosaccharides that have solidified and adhered to these cellulose and lignin components.

[0092] In process (3), wood pellets are produced.

[0093] Wood pellets are produced from the resulting semi-carbonized wood biomaterial.

[0094] This semi-carbonization process is carried out at a temperature of 150 to 220°C, which is lower than the temperature range used in conventional semi-carbonization processes, and therefore semi-carbonized wood material that retains 90 to 95% of the heat generated by the wood material before the process can be obtained in an extremely short period of time.

[0095] Figure 6 shows a micrograph of the wood product treated according to Figure 5 (1). Figure 7 shows a micrograph of the wood product treated according to Figure 5 (2). Figure 8 shows a micrograph of the wood product treated according to Figure 5 (3) (4). Microscopic photograph (1) was taken at a magnification of 35x. The upper photograph in microscopic photograph (1) is a photograph of the wood material (wood chips) that was treated, and the lower photograph is a photograph of the wood biopellets obtained in this example.

[0096] Micrograph (2) was taken at a magnification of 140x. The top photo of micrograph (2) is of wood material (wood chips), and the bottom photo is of wood biopellets obtained in this example. The wood biomaterial was produced by torrefying the wood biomaterial at a temperature typically within 190°C (the same applies below). Micrograph (3) is a photograph of the wood biopellets obtained in this example taken at a magnification of 500x.

[0097] Micrograph (4) is a photograph of the wood biopellets obtained in this example taken at a magnification of 1000x.

[0098] As shown in the photograph of wood material (wood chips), wood material (wood chips) is composed mainly of cellulose components, hemicellulose components, and lignin components, which are connected together in a polymeric state and are formed in an orderly manner without any voids.

[0099] In photos (2) to (4), the wood biopellets are composed of an intermittent state of cellulose components, where high-molecular-weight cellulose components have been degraded, and lignin components, where high-molecular-weight lignin components have been degraded, with multiple hemicellulose-based monosaccharides coagulated and fixed between the degraded cellulose components and degraded lignin components. This state can be seen more clearly at magnifications of 140x (Figure 7), 500x (top photo in Figure 8), and 1000x (bottom photo in Figure 8) than at magnifications of 35x (Figure 6).

[0100] In the case of wood biopellets, they are black overall, indicating that they have been semi-carbonized.

[0101] Thus, the micrograph shows a woody biomaterial that is mainly composed of cellulose, hemicellulose, and lignin components, with low-molecular-weight cellulose and lignin components intermittently present, and with multiple coagulated and fixed hemicellulose-based monosaccharides present between the low-molecular-weight cellulose and lignin components.

[0102] Therefore, according to the present invention, a semi-carbonized wood biomaterial is provided, whose main components are low-molecular-weight cellulose components, low-molecular-weight lignin components, and multiple hemicellulose-based monosaccharides that have solidified and adhered to these cellulose and lignin components.

[0103] FIG. 9 is a diagram illustrating the optimum semi-carbonization process.

[0104] When woody biomaterials treated with subcritical water are torrefied, the amount of carbon produced varies depending on the temperature.

[0105] FIG. 9 shows the optimum temperature range of 180 to 200°C where a large amount of carbon is obtained, the low temperature range of 150 to 180°C where an increased amount of carbon is obtained and is practical, but the amount of carbon is small, and the high temperature range of 180 to 220°C where an increased amount of carbon is obtained and is practical, but the amount of carbon is small.

[0106] The semi-carbonization treatment is carried out by selecting an appropriate temperature within the temperature range of 150 to 220°C.

[0107] For example, 190°C is selected to produce woody biomaterial with a calorific value of 5330 kcal / kg.

[0108] In the temperature range of 150 to 180°C or 180 to 220°C, the thermal energy is less than the maximum calorific value of 5330 kcal / kg, but it is possible to produce woody biomaterial with a calorific value of, for example, 4000 kcal / kg, which is greater than the 3300 kcal / kg of wood chips.

[0109] FIG. 10 shows the produced wood biopellets.

[0110] Figure 10(1) shows a single wood biopellet, and Figure 10(2) shows an aggregated wood biopellet.

[0111] Wood biopellets are produced from wood biomaterials.

[0112] In FIG. 10(1), the produced wood biopellets are cylindrical with a diameter of 6 mm and made of powdered semi-carbonized material.

[0113] The characteristics of the torrefied woody biomaterial are shown in Figs. 6 to 8. While typical wood chips have a calorific value of 3,300 kcal / kg, the torrefied woody biomaterial has a high calorific value of 5,330 kcal / kg.

[0114] FIG. 11 is a diagram showing the process for producing a woody biofuel body.

[0115] FIG. 11(1) is a diagram showing the process of producing a woody biofuel body, and FIG. 11(2) is a partially enlarged view of the solid body.

[0116] The apparatus used is a semi-carbonized carbonized wood biomaterial, which is provided with a subcritical water reaction treatment device and is characterized in that the subcritical water reaction treatment device is used to form semi-carbonized carbonized wood biomaterial, the main components of which are cellulose components degraded from wood material, lignin components degraded from wood material, and multiple hemicellulose-based monosaccharides that have solidified and adhered to these cellulose components and lignin components.

[0117] Subcritical water reaction treatment of wood material 1 using subcritical water reaction treatment device 5 shown in Figure 1 maintains the wood chip shape of wood material 1, reduces the outer size, and forms easily crushable solid body 51 and powder 52.

[0118] As shown in Figure 11(2), the solid 51 consists of a hard layer 61 and a soft layer 62, and these layers contain multiple hemicellulose-based monosaccharides due to hemicellulose saccharification 63, and voids 64 due to hot water treatment with subcritical water were observed.

[0119] The powder 52 is collected 53 and the wood biopellets 7 are produced by the wood biopellet production device 6 as described above.

[0120] In producing wood biopellets 7, powder formed by pulverizing a part of solid body 51 may be mixed with powder 52 and used.

[0121] The solid bodies 51 are aggregated 54 to form solid fuel bodies 55 .

[0122] The woody biopellets 7 and the solid fuel bodies 55 are mixed to form woody biofuel bodies 56 , which are stored in the silo 11 of the gasification furnace 12 and then fed into the gasification furnace 12 .

[0123] A wood biofuel production device using a semi-carbonized carbonization production device is constructed, characterized in that a solid semi-carbonized carbonized material and a powder semi-carbonized carbonized material are produced from the wood material using the subcritical water reaction treatment device, and then mixed to produce wood biofuel.

[0124] FIG. 12 is an explanatory diagram of the gasification process of wood biopellets.

[0125] In Figure 4, we show that wood materials are usually expressed as an S-shaped curve where the temperature X and the weight loss rate Y on the XY axis coordinate system are divided into three sections: the shoulder part of the gradual weight loss line that continues into the part where the weight suddenly decreases, the part of the S-shaped curve where the weight suddenly decreases, and the end part of the S-shaped curve where the weight suddenly decreases and the gradual decrease line ends.

[0126] As mentioned above, the carbon content in the elemental composition of wood chips is about 50%, but in the semi-carbonized material that is hydrothermally treated, it becomes more than 60%, resulting in high energy content.

[0127] After steps (1) to (3) shown in Figure 5, the gasification process of the wood biopellets (step (4)) and the power generation process (step (5)) are carried out. The gasification process of the wood biopellets is completed by steps (1) to (5).

[0128] The shoulder portion is composed mainly of low molecular weight cellulose components, low molecular weight lignin components, and multiple hemicellulose-based monosaccharides that have solidified and adhered to these cellulose and lignin components, forming semi-carbonized wood biomaterial, which allows for the production of semi-carbonized wood biomaterial that retains 90-95% of the heat value before processing.

[0129] The hemicellulose components that make up the woody biomaterial are liquefied and solidified at a temperature set at the shoulder of the S-shaped curve for a predetermined time and under a predetermined pressure, and are then fixed to the other components that make up the woody biomaterial, namely, low-molecular-weight cellulose components and lignin components, to form a woody biomaterial whose main components are multiple fixed hemicellulose-based monosaccharides, low-molecular-weight cellulose components, and lignin components, and the woody biomaterial is then torrefied. A wood biopellet manufacturing device is used to produce wood biopellets from the pretreated wood biomaterial. Wood biopellets are fed into a biogasification furnace and wood biogasification is carried out for a specified time under a specified pressure at a temperature set in the temperature range of 230 to 600°C, which is set at the part of the S-shaped curve where the weight suddenly decreases.

[0130] FIG. 13 is an XY coordinate diagram illustrating the temperature range employed in this embodiment.

[0131] In FIG. 13, the first and second stage processes are shown.

[0132] The first stage treatment refers to the treatment area where the torrefaction of the present invention takes place.

[0133] The second stage of treatment is gasification treatment, i.e., gasification treatment by superheated steam reaction. On the XY axis coordinates, area (1) is shown in the first stage processing, and areas (2) and (3) are shown in the second stage processing.

[0134] The first stage treatment consists of a temperature range of 150 to 220°C and a temperature range of 110 to 130°C, and the torrefaction of the present invention is carried out in the first stage treatment.

[0135] In the temperature range of 150 to 220°C, hemicellulose components are saccharified to produce multiple hemicellulose-based monosaccharides.

[0136] This temperature range is also the temperature range in which hemicellulose components liquefy and volatilize, with most of them liquefying.

[0137] The temperature range of 110 to 130°C is the temperature range in which multiple hemicellulose-based monosaccharides solidify and solidify.

[0138] The treatment (2) in FIG. 5 is carried out in the temperature range of 150 to 220°C in the first stage treatment and in the temperature range of 110 to 130°C.

[0139] The treatment (4) in FIG. 12 is carried out in the temperature range of 230 to 600° C. in the second stage treatment.

[0140] In a conventional example of torrefaction, it has been proposed to perform torrefaction at a temperature of 200 to 320°C.

[0141] Although the temperature range for the torrefaction of the present invention is partly lapped at 200 to 220°C, the present invention differs in that the temperature range for the torrefaction of the present invention is set after performing the process (1) in Fig. 5. That is, the present invention is characterized by having a step of performing subcritical water reaction treatment to set the temperature range for the torrefaction of the present invention.

[0142] (2) Regarding area selection: A temperature between 230 and 450°C is selected.

[0143] (3) Regarding area selection: A temperature between 450 and 600°C is selected.

[0144] FIG. 14 is a diagram showing steps of a woody biogas production method according to an embodiment of the present invention.

[0145] First stage processing Pretreatment by subcritical water treatment reaction: Raw wood material is fed into the subcritical water reaction treatment device Wood raw materials are treated with subcritical water to reduce their molecular weight The woody biomaterial after the subcritical water reaction treatment is then subjected to pretreatment.

[0146] Torrefaction process: The hemicellulose component is liquefied to produce multiple hemicellulose-based monosaccharides, and the temperature is adjusted to 110 to 130°C to solidify and fix the multiple hemicellulose-based monosaccharides to the low-molecular-weight cellulose and lignin components.

[0147] By this fixation, multiple hemicellulose-based monosaccharides are retained in the wood material as a heat source. Through these processes, wood is semi-carbonized and the semi-carbonized wood biomaterial is Generate.

[0148] Wood biopellets are then produced.

[0149] Second stage processing Wood biogas production The wood biopellets produced in the first stage are fed into the wood biogasification furnace. Wood biopellets are gasified while the hydrogen concentration is suppressed.

[0150] Gas temperature: 230~600℃ Processing time: 15-60 minutes [Explanation of symbols]

[0151] 100...wood biogas generation system, 1...wood material (organic matter from forest residues, processed raw material), 2...biopellet manufacturing equipment, 3...biogas production equipment, 4...superheated steam generator, 5...subcritical water reaction equipment, 6...wood biopellet manufacturing equipment, 7...wood biopellets (torrefaction pellets), 8...transport means, 11...silo, 12...superheated steam gasifier (referred to as gasifier), 13...bag filter, 14...buffer tank, 15...gas engine, 16...superheated steam generator, 17...generator, 19...carbonized material discharge device, 20...carbonized material (carbonized material including wood biomaterial), 21...fuel, 22...wood biogas generation, 51...solid material, 52...powder, 55...solid fuel body, 56...wood biofuel body.

Claims

1. A semi-carbonized wood biomaterial whose main components are cellulose components formed by depolymerizing high molecular weight cellulose components, lignin components formed by depolymerizing high molecular weight lignin components, and multiple hemicellulose-based monosaccharides that have solidified and adhered to these cellulose and lignin components.

2. Semi-carbonized wood biopellets whose main components are cellulose components formed by decomposing high molecular weight cellulose components into smaller molecules, lignin components formed by decomposing high molecular weight lignin components into smaller molecules, and multiple hemicellulose-based monosaccharides that have solidified and adhered to these cellulose and lignin components.

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