Wood biopellets and wood biopellets

Abstract

A semi-carbonized carbonized material is produced from the raw wood material to be treated, a highly energy semi-carbonized carbonized material is produced from the raw wood material to be treated, and a highly energy wood biogas is produced from the highly energy semi-carbonized carbonized material. [Solution] A semi-carbonized wood biomaterial or wood biopellet, whose main components are cellulose components formed by decomposing high molecular weight cellulose components into lower molecular weight lignin components, and a number of hemicellulose-based monosaccharides that have solidified and adhered to these cellulose and lignin components.

Description

[Technical field]

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

[0002] There is a known method of semi-carbonizing wood material (also called wood chips) and turning the resulting semi-carbonized 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 semi-carbonization is 200 to 300°C, the residence time is about 60 minutes, and the semi-carbonized material is stored in a drum at the exit of the rotary kiln.

[0003] "Semi-carbonization," also known as "torrefaction," is a fuel conversion technology that decomposes organic matter into substances with a high carbon content by heating woody biomass at 200-300°C in low-oxygen conditions. It is known that semi-carbonization increases energy density and improves crushability and water resistance, and some semi-carbonization processing equipment can perform drying and semi-carbonization in one machine, blowing hot air directly onto the raw material, resulting in a high semi-carbonization speed.

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

[0005] The pelletizing equipment used is capable of forming the 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 many forest resources, which makes it easy to use them on a small scale, and it can also be used to replace fossil fuels with local resources, contributing to the revitalization of local areas.

[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 of wood are polymers such as cellulose, hemicellulose, and lignin, with hemicellulose accounting for about 20% and cellulose and lignin for 80%. When wood is heated, the polymer components are pyrolyzed into lower molecules, and the remainder becomes a carbonized residue. Each of these components decomposes at different temperatures: hemicellulose decomposes at about 450-570K (177-297℃), cellulose at 510-670K (237-397℃), and lignin at 550-820K (277-547℃).

[0009] A wood biogasification power generation system is known. The wood biogasification power generation system includes a fixed-bed gasification furnace, 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 for 5 to 90 minutes in the temperature range of 200 to 240°C, where the decomposition of hemicellulose proceeds slowly, the hemicellulose decomposition products volatilize and diffuse outside the carbonized material before charring. It 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 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 hydrothermally carbonizing EFB (palm oil residue) at a temperature of 150 to 250°C and a pressure of 0.3 to 4.2 MPa (G).

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

[0014] [Patent Document 1] JP 2020-45373 A [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 in which semi-carbonized charcoal is produced from the raw wood material to be processed, and the semi-carbonized charcoal is gasified in a wood biogasification furnace. The amount of semi-carbonized charcoal produced from the wood material is reduced, and a large amount of semi-carbonized charcoal is not obtained with high energy compared to the amount of raw wood 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. In order to make effective use of forest residues that are distributed on a small scale and to replace fossil fuels with forest residues, which are a local resource, and to contribute to the revitalization of the region through such replacement, an effective method of using 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 apparatus, 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 has an objective of producing a large amount of semi-carbonized carbonized material with higher energy than the amount of raw wood material from a raw wood material, thereby generating a large amount of high-energy wood biogas. [Means for solving the problem]

[0019] The present invention relates to A cellulose component obtained by depolymerizing a high molecular weight cellulose component, a lignin component obtained by depolymerizing a high molecular weight lignin component, and solidified and fixed to these cellulose components and lignin components. Hemi We propose semi-carbonized charcoal-based wood biomaterial and / or wood biopellets, which are mainly composed of multiple cellulose-based monosaccharides.

[0020] In some literature, wood biopellets are sometimes called wood biomass pellets. Effect of the Invention

[0021] According to the present invention, as described above, By performing the subcritical water reaction treatment through hydrolysis, low molecular weight wood biomaterial is produced from the input wood material, and from the subcritical water reaction treated wood biomaterial, a semi-carbonized charred wood biomaterial can be formed, which is mainly composed of low molecular weight cellulose components, low molecular weight lignin components, and multiple hemicellulose-based monosaccharides that are solidified and fixed to these cellulose components and lignin components.

[0022] When the change in temperature X and weight loss rate Y of the wood material is expressed on the XY axis coordinate system as an S-shaped curve 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 curve of the sudden 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 wood biomaterial are liquefied and solidified, and multiple hemicellulose-based monosaccharides are fixed to the other components that form the wood biomaterial, namely, the low molecular weight cellulose components and low molecular weight lignin components, forming a wood biomaterial composed mainly of low molecular weight cellulose components and lignin components with the multiple hemicellulose-based monosaccharides fixed thereto, and this wood biomaterial composed mainly of low molecular weight cellulose components and lignin components can be semi-carbonized.

[0023] The 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 a semi-carbonized product that retains 90 to 95% of the heat generated by the wood material before the process.

[0024] Furthermore, according to the present invention, wood biogas can be efficiently produced using the semi-carbonized charcoal with high energy content. [Brief description 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. [Diagram 2] FIG. 1 is a diagram showing the configuration of a subcritical water reaction treatment apparatus according to an embodiment of the present invention. [Diagram 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] A diagram showing the relationship between processing temperature and wood weight change, with X being the XY axis coordinate and Y being the weight change of the wood. [Diagram 5] A diagram on the XY axis coordinate system explaining the fixation of multiple monosaccharides of hemicellulose to the low molecular weight cellulose and lignin components that form wood biomaterial, and the semi-carbonization process. [Figure 6] Micrograph of the product of wood treated according to Figure 5 (1) [Figure 7] Micrograph of the product of wood treated according to Figure 5 (2) [Figure 8]Micrographs of the products of wood 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 wood biofuel bodies. [Figure 12] Diagram of the gasification process of wood biopellets [Figure 13] A diagram illustrating the area adopted in the present invention using an XY-axis coordinate system. [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 PREFERRED EMBODIMENTS

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

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

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

[0029] The biopellet production apparatus 2 is composed of a subcritical water reaction apparatus 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 led to the subcritical water reaction apparatus 5.

[0030] Organic matter from forest residues (hereinafter referred to as forest residues), i.e., wood material to be treated (so-called wood chips), is collected from forests in various locations by any means, crushed, and fed 8 in the form of crushed wood material (hereinafter referred to as wood material 1) into a subcritical water reaction apparatus 5. A typical example of wood material is cedar wood. Wood material can be rephrased as 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 reaction device 5 performs subcritical water reaction treatment on the input wood material 1 to form wood biomaterial.

[0032] Subcritical water reactions are a process in which high-temperature, high-pressure water is sealed in a pressure vessel to rapidly hydrolyze the organic matter put in and break it down into smaller molecules. A subcritical water reaction device (also called a subcritical treatment device or subcritical device) is used.

[0033] The wood biomaterial is sent to a wood biopellet production device 6, which produces wood biopellets 7. The wood biopellet production device 6 produces wood biopellets 7 using the wood biomaterial in accordance with a known method.

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

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

[0036] The biogas production apparatus 3 is equipped, along the flow path, with 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 gasification furnace 12, and a generator 17 is connected to the gas engine 15. A belt conveyor 18 is provided between the silo 11 and the gasification furnace 12, and a char discharge device 19 is provided below the gasification furnace 12, through which char 20 is discharged from the gasification furnace 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. A 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 and gasified with superheated steam from the superheated steam generator 16 to become wood biogas. The wood biogas produced at this time is subjected to a subcritical water reaction process to become high-energy wood biogas with a high carbon C content due to the characteristics of the wood biopellets formed, as will be described later. The gasifier 12 produces 22 even more high-energy wood biogas.

[0040] As described below, by applying an improved wood gas production method to the formed wood biopellets, in addition to the above high energy, it becomes a wood biogas with even higher energy. The gas furnace 12 can generate 22 even higher energy wood biogas.

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

[0042] Thus, the wood biogas production system 100 shown in Figure 1 is composed of a first stage component that produces wood biopellets through subcritical water reaction treatment in the biopellet production apparatus 2, and a second stage component that produces wood biogas from the highly-energized wood biopellets in the biogas production apparatus 3.

[0043] FIG. 2 is a diagram showing the configuration of a wood biopellet production 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 the hydrothermal reaction treatment system 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 the 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 connected to a processing material input system, a methane recovery system, a hydrothermal reaction process, and a semi-carbonization process system. A control device 105 is provided to control the temperature, pressure, and process time in the pressure vessel.

[0046] The pressure vessel 101 is composed of an outer cylindrical vessel (also called the outer jacket) 111 and an inner cylindrical vessel (also called the inner jacket) 112 arranged with a space on the inner wall of the outer cylindrical vessel 111, 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 lids 114, 115 for closing at both ends, and one of the lids 115 is provided with a driving motor 116 on its side. The driving motor 116 is connected to a stirrer 113 having a rotating blade.

[0048] An outer temperature sensor and an outer pressure sensor 121 for measuring 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 for measuring the temperature and pressure in the space (inner space) 106 of the inner cylindrical container 112, and a moisture sensor 123 for measuring the moisture in the space of the inner cylindrical container 112 are provided, and the temperature and pressure in the inner space 106 and the moisture in the inner space 106 of the inner cylindrical container 112 are measured, 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 a recording means of the control device 105. The measured moisture amount is used to set control data for the semi-carbonization 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 within the inner space can be discharged to the outside. The pressure vessel 101 is provided 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 semi-carbonized material produced by the hydrothermal reaction process can be recovered to the outside, i.e., to a semi-carbonized 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 to 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 to be processed 131 (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 a raw material processor. By attaching a photographing means (not shown) near the input hopper 125, comparing the image with a reference image, and providing a means for identifying the type of raw material to be processed (not shown), it is possible to automatically identify the type of raw material to be processed. Identification data is input to the control device 105.

[0053] The boiler 102 includes a steam supply passage 133 that supplies the generated steam to the pressure vessel 101. A superheated steam generator 140 is provided in the steam supply passage 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 for supplying superheated steam into the space between the outer cylindrical vessel 111 and the inner cylindrical vessel 112 and a branch line 135 for supplying superheated steam into the space of the inner cylindrical vessel 112, and each branch line is provided with a control valve 136, 137. The control valves 136, 137 are connected to the control device 105, and the opening and closing of the control valves 136, 137 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 of 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 in 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 material 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 the 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 of the inner cylindrical vessel is 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 material as the processing result of the wood.

[0058] For example, water vapor is introduced into the inner space, a hydrothermal reaction temperature in the subcritical reaction range of water is adopted, and a hydrothermal reaction zone is formed in which the hydrothermal reaction pressure is within 2.5 MPa, typically within 0.3 to 3.5 MPa, and the hydrothermal reaction time is controlled to an appropriately set time, and wood material 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 / semi-carbonization treatment area, a semi-carbonized powder treatment temperature obtained from the type of raw material to be treated and the calorific value multiple is set under a specified pressure, and a semi-carbonized powder material is produced from the hydrolysis treatment material using a hydrothermal reaction process, which has a specified calorific value relative to the calorific value of the wood chips.

[0061] In the outer space, a semi-carbonization treatment area is formed in which the carbonization temperature is within a range of 150 to 220°C and the treatment time is controlled, and semi-carbonized pellets based on hydrothermal reaction are formed from the hydrolysis treatment material, typically semi-carbonized pellets using a hydrothermal reaction process with a high calorific value. Semi-carbonized solids that are dried, semi-carbonized, and powdered are produced. A part of the semi-carbonized material may be used for other purposes.

[0062] Wood chips with a moisture content of 35-50% and a calorific value of 3300 kcal / kg are widely known. In the case of a low calorific value, it has been reported that the value is 3040 kcal / kg. In the present invention, when calculating the calorific value multiple, wood chips with a calorific value of 3300 kcal / kg are used as the reference wood chips. The inventors' analysis also confirmed that semi-carbonized materials have a calorific value of 3300 kcal / kg.

[0063] According to the experiments of the inventors, it was confirmed that by providing a semi-carbonized pellet forming system, it is possible to produce semi-carbonized products that have a calorific value 1.25 times that of wood chips, which have a calorific value of 3,300 kcal / kg, and that are hydrothermally treated. The carbon content of the elemental composition of wood chips is about 50%, but in the case of semi-carbonized products that have been hydrothermally treated, this becomes 60% or more, resulting in high energy content.

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

[0065] When the powder particle-like semi-carbonized material is obtained, a semi-carbonized pellet based on a hydrothermal reaction can be formed in the form of an aggregate of the semi-carbonized material after the powder particle semi-carbonization by hydrothermal reaction, mainly consisting of the semi-carbonized material described above.

[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 inner 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. The container is divided into two parts. 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 area can be formed in the internal space by a first heating means, in which a hydrothermal reaction is carried out by hydrolysis under a hydrothermal reaction pressure; 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 / semi-carbonization treatment area.

[0070] Furthermore, a system is configured which includes a subcritical water reaction apparatus 5 using a pressure vessel having a double-pipe configuration, a hydrothermal reaction treatment and semi-carbonization powder treatment system 6, and the subcritical water reaction apparatus 5, and which uses the subcritical water reaction apparatus 5 as a heating means, i.e., 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 source 102A is provided in parallel with the boiler 102. The heating power source 102A is connected to the control device 105 by 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 from a heater 117 instead of by steam heat. However, the same is true in that a dried and torrefied hydrothermal torrefied material capable of producing torrefied pellets by hydrothermal reaction from a hydrolysis treatment substance, typically torrefied pellets with a high calorific value, is produced.

[0076] This is the same as in the previous example in that water vapor is introduced into the inner space, and a low-temperature hydrolysis treatment area is formed in which the temperature is 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 treatment time is controlled as appropriate, and wood material is hydrolyzed to form a semi-carbonized product, which is a powdered hydrolysis treatment substance. However, what is different is that a low-temperature drying / semi-carbonization treatment area is formed in the outer space, where the semi-carbonization temperature is above the hydrothermal reaction temperature and within 220°C, and the treatment time is controlled, and is electrically heated by heater 117 via current from heating power source 102A.

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

[0078] This is a diagram showing the relationship between the processing temperature and the weight change of the wood material, with the processing temperature X and the weight change Y of the wood material represented as XY coordinates. It is known that when the wood material is carbonized, the relationship between the temperature X and the weight loss rate Y is expressed as an S-shaped curve on the XY coordinates, which is divided into three sections: the shoulder part of the gradual weight loss line that continues to the part where the weight decreases rapidly, the S-shaped curve where the weight decrease rapidly ends, and the end part of the S-shaped curve where the weight decrease ends and the gradual decrease line begins.

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

[0080] The International Energy Agency (IEA) defines "torrefaction" as "a 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] FIG. 5 is a diagram illustrating the coagulation, fixation, and semi-carbonization process of multiple hemicellulose-based monosaccharides into the lower molecular weight cellulose components and lignin components that form woody biomaterial, on the XY axis coordinate system.

[0082] The semi-carbonization process at low temperatures associated with the subcritical water reaction process 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 temperature.

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

[0088] 1st stage: Temperature treatment at 150 to 220°C In order to liquefy the hemicellulose components in the wood material, the wood is heated to this temperature and maintained at this temperature to liquefy the hemicellulose components in the wood material. A plurality of monosaccharides of the liquefied hemicellulose system are generated and exist between the low molecular weight cellulose components and the low molecular weight 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 components and lignin components.

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

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

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

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

[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 a semi-carbonized material that retains 90 to 95% of the heat value of the wood material before the process can be obtained in an extremely short period of time.

[0095] Figure 6 shows a micrograph of the product of wood processed according to Figure 5 (1). Figure 7 shows a micrograph of the product of wood treated according to Figure 5 (2). Figure 8 shows micrographs of the products of wood 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 treated wood material (wood chips), 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, with the upper photo of micrograph (2) being of wood material (wood chips) and the lower photo being of wood biopellets taken in this example. The wood biomaterial was produced by semi-carbonizing 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, hemicellulose and lignin components that are connected together in a polymeric state, and are formed in an orderly manner with no voids.

[0099] In photos (2) to (4), the wood biopellets are in a state where the cellulose components, which are high-molecular-weight cellulose components, and the lignin components, which are high-molecular-weight lignin components, are intermittent, and there are multiple hemicellulose-based monosaccharides that have solidified and adhered 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) compared to 35x (Figure 6).

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

[0101] In this way, the micrograph shows a woody biomaterial that is mainly composed of cellulose components, hemicellulose components and lignin components, with low molecular weight cellulose components and low molecular weight lignin components presenting an intermittent state, and with multiple coagulated and fixed hemicellulose-based monosaccharides present between the low molecular weight cellulose components and low molecular weight lignin components.

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

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

[0104] When wood biomaterial treated with subcritical water reaction is torrefied, the amount of carbon produced varies depending on the temperature.

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

[0106] The semi-carbonization process 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 150 to 180°C temperature range or the 180 to 220°C temperature range, although the thermal energy is less than the maximum calorific value of 5,330 kcal / kg, it is possible to produce wood biomaterial with a large calorific value, for example 4,000 kcal / kg, compared to the 3,300 kcal / kg of wood chips.

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

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

[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 wood biomaterial are shown in Figs. 6 to 8. The torrefied wood biomaterial has a high calorific value of, for example, 5,330 kcal / kg, compared to the calorific value of 3,300 kcal / kg of typical wood chips.

[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 for producing a woody biofuel body, and FIG. 11(2) is a partially enlarged view of the solid body.

[0116] The apparatus used is characterized in that it is equipped with a subcritical water reaction treatment device, and in that the subcritical water reaction treatment device is used to form a semi-carbonized wood biomaterial, the main components of which are cellulose components that have been broken down into smaller molecular weight components from wood material, lignin components that have been broken down into smaller molecular weight components, and a plurality of hemicellulose-based monosaccharides that have been solidified and fixed to these cellulose components and lignin components.

[0117] By the subcritical water reaction treatment of the wood material 1 in the subcritical water reaction treatment device 5 shown in FIG. 1, the wood chip shape of the wood material 1 is maintained, the outer shape is reduced, and a solid body 51 and powder 52 that are easily crushed are formed.

[0118] As shown in FIG. 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 bio-pellets 7, a powder formed by pulverizing a part of solid body 51 may be mixed with powder 52 and used.

[0121] The solid bodies 51 are assembled 54 to form a solid fuel body 55 .

[0122] The wood biopellets 7 and the solid fuel bodies 55 are mixed to become wood 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 apparatus using the semi-carbonized carbonization production apparatus 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 apparatus, and these are 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 material is usually expressed as an S-shaped curve on the XY axis coordinate system, where the temperature X and the weight loss rate Y are divided into three sections: the shoulder part of the gradual weight loss line that continues into the part of rapid weight loss, the S-shaped curve of rapid weight loss, and the end of the S-shaped curve of the gradual weight loss line where the rapid weight loss ends.

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

[0127] 5, the gasification process of the wood biopellets (process (4)) and the process for power generation (5) are carried out continuously. The gasification process of the wood biopellets is completed by the processes (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 to form a semi-carbonized wood biomaterial, which allows for the production of semi-carbonized wood biomaterial that retains 90-95% of the heat generated before processing.

[0129] The hemicellulose components that form the wood biomaterial are liquefied and solidified at a temperature set at the shoulder of the S-shaped curve for a specified time and under a specified pressure, and are fixed to the other components that form the wood biomaterial, namely, low molecular weight cellulose components and lignin components, to form a wood biomaterial mainly composed of fixed hemicellulose-based monosaccharides, low molecular weight cellulose components and lignin components, and the wood biomaterial is semi-carbonized. A wood bio-pellet production device produces wood bio-pellets from the pretreated wood bio-material, 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 for explaining the temperature region employed in this embodiment.

[0131] In FIG. 13, a first stage process and a second stage process are shown.

[0132] The first stage process represents the process area where the torrefaction of the present invention takes place.

[0133] The second stage treatment is the gasification treatment, i.e. the gasification treatment region 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 in the first stage treatment, the semi-carbonization of the present invention is carried out.

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

[0136] This temperature range is also where the 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 monosaccharides of hemicellulose solidify and solidify.

[0138] The treatment (2) in FIG. 5 is carried out in a temperature range of 150 to 220°C in the first stage treatment and in a 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] As an example of conventional semi-carbonization, it has been proposed to carry out the process at temperatures between 200 and 320°C.

[0141] Although a part of the temperature range shown in the semi-carbonization of the present invention is wrapped at 200 to 220°C, the present invention is different in that the temperature range for the semi-carbonization of the present invention is set after carrying out the process (1) in Fig. 5. That is, the present invention is characterized in that it has a step of carrying out a subcritical water reaction treatment to set the temperature range for the semi-carbonization of the present invention.

[0142] (2) About the selection of the area: A temperature within the range of 230 to 450°C is selected.

[0143] (3) About the selection of the area: A temperature within the range of 450 to 600°C is selected.

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

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

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

[0147] This fixation allows a plurality of hemicellulose-based monosaccharides to be 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, processing 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 biopellet (torrefaction pellet), 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...charcoal discharge device, 20...charcoal (charcoal including wood biomaterial), 21...fuel, 22...generation of wood biogas, 51...solid body, 52...powder, 55...solid fuel body, 56...wood biofuel body.

Claims

1. A semi-carbonized wood biomaterial, The raw wood material to be treated is subjected to a subcritical water reaction treatment at a treatment temperature of 150 to 220°C for a treatment time of 15 to 60 minutes, whereby low molecular weight cellulose components and low molecular weight lignin components are formed from the cellulose components and lignin components of the wood material, and hemicellulose components are liquefied from the hemicellulose components, and the hemicellulose components are solidified and fixed to the cellulose components and lignin components by a temperature treatment of 110 to 130°C to form a wood biomaterial, and the wood biomaterial is a semi-carbonized wood biomaterial that is the main component and retains 90% of the heat generation amount retained by the raw wood material to be treated.

2. A semi-carbonized wood biopellet formed from semi-carbonized wood biomaterial, A semi-carbonized wood biopellet formed from a semi-carbonized wood biomaterial in which a raw material wood is treated with a subcritical water reaction at a treatment temperature of 150 to 220°C for a treatment time of 15 to 60 minutes, so that low-molecular-weight cellulose components and low-molecular-weight lignin components are formed from the cellulose components and lignin components of the wood, and hemicellulose components are liquefied from the hemicellulose components, and the hemicellulose components are solidified and fixed to the cellulose components and lignin components by a temperature treatment of 110 to 130°C, and the wood material containing the wood biomaterial as a main component retains a heat generation amount that is 90% of the heat generation amount retained by the raw material wood.

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