Biogas plant, biogas production processing method, and biogas production processing residue

Abstract

To collect biogas subjected to highly efficient methane fermentation by using a waste raw material increased in calorie by pre-treatment; and to efficiently and effectively utilize a post-processing residue after collecting the biogas by post-treatment.SOLUTION: A biogas plant is provided with a semi-carbonized pellet forming system comprising: a drying treatment residue recovery device; a hydrothermal reaction treatment device that receives the drying treatment residue from the drying treatment residue recovery device and subjects the drying treatment residue to hydrothermal reaction treatment to form a semi-carbonized powder product in a powder form by semi-carbonization; a semi-carbonized powder product recovery device that recovers the formed semi-carbonized powder product; and a semi-carbonized pellet forming device that forms semi-carbonized pellets from the semi-carbonized powder product.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a biomass gas plant, a biomass gas generation treatment method, and a biomass gas generation treatment residue.

Background Art

[0002] The use of waste-based biomass, that is, waste raw materials, is effective not only for the formation of a recycling-based society but also for global warming by reducing the emission of greenhouse gases, and a treatment method by methane gasification of waste raw materials (that is, biomass gasification) is required.

[0003] Many vertical dry methane fermentation facilities have been proposed for the methane gasification of waste raw materials. With vertical dry methane fermentation facilities, biogas has been generated from various types of waste as raw materials and reused as energy.

[0004] In addition, various hydrothermal reaction treatment devices have been proposed as effective methods for the treatment method by methane gasification of waste raw materials.

[0005] Patent Document 1 describes a treatment method for organic waste comprising a methane fermentation step, an incineration step of methane fermentation residue, and a methane gas recovery step.

[0006] Patent Document 2 describes a vertical dry anaerobic methane fermentation tank.

[0007] Patent Document 3 describes a treatment method for organic waste using a plurality of fermentation tanks.

[0008] Patent Document 4 describes a high-efficiency methane fermentation method that uses subcritical water treatment to increase the methane recovery amount from food waste, re-treats the methane fermentation digestion residue with subcritical water to recover methane, and reduces the amount of methane fermentation digestion residue.

[0009] Patent Document 5 describes methane fermentation using pulverized bark fly ash treated with a fryer.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0011] As shown in the above-mentioned patent documents, in order to adopt a high-efficiency methane fermentation method using a methane fermentation tank, particularly a vertical dry anaerobic methane fermentation tank, it is necessary to perform pretreatment to increase the energy of waste raw materials. Patent Document 4 or 5 shows subcritical water treatment, that is, hydrothermal reaction treatment or fluidization treatment by a fluidizer, as the pretreatment.

[0012] Patent Document 4 describes a method of subjecting methane fermentation digested residue to subcritical water treatment again to recover methane and reduce the amount of methane fermentation digested residue, but it does not describe effectively utilizing the treated residue without waste treatment.

[0013]

[0014] When adopting a high-efficiency methane fermentation method in a vertical dry anaerobic methane fermentation tank to form a recycling society, it is not enough to only increase the recovery amount of biogas by highly efficiently methane-fermenting waste raw materials in the pretreatment. It is required to be able to efficiently and effectively utilize the treated residue after collecting biogas in the post-treatment without waste treatment.In view of this, in forming a recycling-based society, the present invention adopts a high-efficiency methane fermentation method in a vertical dry anaerobic methane digester, and uses waste materials with increased calorie content in the pretreatment to perform high-efficiency methane fermentation to collect biogas, and aims to enable efficient utilization of the treated residue after collecting biogas in the post-treatment.

Means for Solving the Problems

[0015] The present invention relates to a biomass gas plant comprising a waste material receiving device for receiving waste materials such as domestic waste, food residues, livestock manure, and plant residues, a pretreatment device for performing high-energy treatment of waste materials in the pretreatment before input into the methane digester, a vertical dry methane fermentation device equipped with a methane digester for inputting the waste materials after pretreatment and performing methane fermentation, a biomass gas recovery device for recovering biomass gas containing fermented methane gas, and a dry treatment residue recovery device for recovering the dry treatment residue after recovering the biomass gas. In the biomass gas plant, a semi-carbonized pellet formation system is provided, which consists of a dry treatment residue recovery device, a hydrothermal reaction treatment device that receives the dry treatment residue from the dry treatment residue recovery device, performs hydrothermal reaction treatment on the dry treatment residue to generate a semi-carbonized powder product in a semi-carbonized and powdered state, a semi-carbonized powder product recovery device for recovering the generated semi-carbonized powder product, and a semi-carbonized pellet generation device for generating semi-carbonized pellets from the semi-carbonized powder product. A biomass gas plant characterized by the above is proposed.

Effects of the Invention

[0016] According to the present invention, a hydrothermal reaction treatment device can be provided on the downstream side of the treatment residue recovery device to perform hydrothermal reaction treatment on the treatment residue, pulverize it, and a semi-carbonized pellet formation system for generating semi-carbonized pellets can be provided.

[0017] Thus, in the formation of a recycling-based society, an efficient methane fermentation method is adopted in a vertical dry anaerobic methane fermentation tank, and high-efficiency methane fermentation is carried out by using waste raw materials with increased calorie content in the pretreatment to collect biogas, and the treated residue after collecting the biogas in the post-treatment can be efficiently and effectively utilized.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0019] FIG. 1 is a diagram showing the configuration of the biomass gas plant according to the present invention.

[0020] In FIG. 1, the treatment of waste raw materials by the biomass gas plant 100 is composed of an A waste raw material collection / input treatment, a B pretreatment, a C fermentation treatment, and a D post-treatment.

[0021] The A waste raw material collection / input treatment is a process for collecting and inputting waste raw materials.

[0022] This process is composed of collecting solid and liquid waste raw materials 1 by waste raw material collection means (not shown), inputting 2 to the adjuster 3 for adjusting the physical size, adjusting by the adjuster 3 for the received solid waste raw materials 1, and sorting by the sorter 4 for sorting out metal scraps or pottery scraps unsuitable for methane fermentation from the adjusted waste raw materials 1, and excluding these scrap substances from the pulverized waste raw materials 1.

[0023] The waste raw materials include household waste, food residues, livestock manure, plant residues, and liquid waste raw materials.

[0024] Step B pretreatment is a process of generating high-calorie waste raw materials 1 by treatment with a fryer 5 or / and a hydrothermal reaction treatment device 6.

[0025] The fryer 5 fries the powdered waste raw materials 1 with an oil component, typically collected waste oil, to obtain fried waste raw materials 1.

[0026] The hydrothermal reaction treatment device 6 subjects the powdered waste raw materials 1 to hydrothermal reaction treatment to obtain crushed semi-carbonized waste raw materials 1.

[0027] A conveyor means 7 is connected to the fryer 5 to introduce the fried waste raw materials 1 into a crusher 8. The fried and crushed waste raw materials 1 are introduced into a conveyor 9 and conveyed by the conveyor 9 to a vertical dry methane fermentation device 12.

[0028] A boiler 11 equipped with a superheater is connected to the hydrothermal reaction treatment device 6, and steam for the hydrothermal reaction treatment is introduced into the hydrothermal reaction treatment device 6.

[0029] The hydrothermal reaction treatment device 6 includes a reaction vessel 6A, a stirrer 6B installed in the reaction vessel, and a drive device 6C, and crushes and semi-carbonizes the waste raw materials 1 by hydrothermal reaction treatment in the reaction vessel.

[0030] The waste raw materials 1 crushed and semi-carbonized by hydrothermal reaction treatment in the hydrothermal reaction treatment device 6 are introduced into a conveyor 9 and conveyed by the conveyor 9 to a vertical dry methane fermentation device 12.

[0031] A fryer 5 for making waste raw materials into a fried state with oil content or and a hydrothermal reaction treatment device for subjecting the pulverized waste raw material 1 to hydrothermal reaction treatment are provided on the upstream side of the vertical dry methane fermentation device 12, and the waste raw material 1 can be subjected to frying treatment by the fryer or hydrothermal reaction treatment by the hydrothermal reaction treatment device.

[0032] Change the conveying path from the conveying path shown in Fig. 1, provide a fryer for making waste raw materials into a fried state with oil content and a hydrothermal reaction treatment device for subjecting the waste raw material to hydrothermal reaction treatment, put the waste made into a fried state by the fryer into the hydrothermal reaction treatment device for hydrothermal reaction treatment, and then put it into the methane gas recovery device, or put the waste subjected to hydrothermal reaction treatment by the hydrothermal reaction treatment device into the fryer to make it into a fried state with waste oil and then put it into the methane gas recovery device.

[0033] As described above, the waste raw material 1 is in any form of a collected state, a powdered state, a fried state, a fried and crushed state, and a state crushed by hydrothermal reaction treatment.

[0034] The C fermentation treatment is a process of fermenting high-calorie biogas composed of the generation of biogas mainly composed of methane gas (CH 4 ) and carbon dioxide (CO 2 ) using the waste raw material 1 that has been pretreated and has a higher calorie content by the vertical dry methane fermentation device 12.

[0035] The vertical dry methane fermentation device 12 includes a methane fermentation tank 21 that is a vertical cylindrical container, a stirrer 22 and a drive device 23 disposed in the methane fermentation tank, and is fixed to the foundation base 25 by a frame body 24.

[0036] A supply screw conveyor 32 equipped with a spraying device 31 is provided above the methane fermentation tank 21.

[0037] A seed sludge digestion tank 33 having anaerobic seed sludge is provided and connected to the spraying device 31.

[0038] The fly-ash converted, crushed waste raw material 1, or the crushed and semi-carbonized waste raw material 1 conveyed from the conveyor 9 by the conveyor 9 is introduced into the spraying device 31. Here, the inoculum from the inoculum digestion liquid tank 33 is sprayed and mixed with the waste raw material 1.

[0039] The waste raw material 1 mixed with the inoculum is supplied to the upper part of the vertical dry methane fermentation device 12 by the supply screw conveyor 32.

[0040] The supply screw conveyor 32 supplies the waste raw material 1 mixed with the closely adhered inoculum to the upper part of the vertical dry methane fermentation device 12, thereby preventing air from entering the vertical dry methane fermentation device and maintaining the anaerobic state inside the vertical dry methane fermentation device.

[0041] A hot air generating device 34 with adjustable temperature is fixedly provided on the frame 24. The hot air generated by the hot air generating device 34 and adjusted in temperature is led to a hot air circulation device (not shown) provided inside a heat preservation jacket 35 arranged on the inner wall of the methane fermentation tank 21, and the hot air circulates inside the heat preservation jacket 35.

[0042] Instead of the hot air generating device 34, a hot water generating device or a steam generating device may be used. The hot water generating device or the steam generating device generates hot water or steam, and the hot water or steam is circulated inside the heat preservation jacket 35. As the liquid temperature, a temperature condition of 30 - 60°C is adopted.

[0043] By introducing the above-mentioned heating medium into the heat preservation jacket 35, the temperature inside the cylindrical container is maintained at the appropriate temperature for anaerobic digestion by the inoculum.

[0044] A drying treatment residue recovery device (treatment residue discharging means) 41 is provided and connected to the lower part of the methane fermentation tank 21. The drying treatment residue recovery device 41 includes a cylindrical container 41A, a screw conveyor 41B, a driving device 41C, a rotary bubble (not shown), and a control panel (not shown), and discharges the dried treatment residue after methane gas is discharged, which is generated by the vertical dry methane fermentation device 12, to a hydrothermal reaction treatment device 50 provided outside. The hydrothermal reaction treatment device 50 is separate from the above-described hydrothermal reaction treatment device 6.

[0045] In the vertical dry methane fermentation device 12, methane fermentation is carried out in an anaerobic state at an appropriate temperature by the action of anaerobic inoculum. As described above, biogas mainly composed of methane gas and carbon dioxide is generated.

[0046] The waste raw material 1 introduced into the methane fermentation tank 21 is calorie-enriched in the pretreatment stage, and the amount of biogas obtained per unit weight of the waste raw material is larger than that in the case where it is not calorie-enriched.

[0047] The biogas fermented from the upper part of the methane fermentation tank 21 is discharged to the biogas recovery device 60. The treatment residue after biogas is discharged from the lower part is discharged to the hydrothermal reaction treatment device 50. The configuration of the hydrothermal reaction treatment device 50 is the same as that of the previous hydrothermal reaction treatment device 6.

[0048] The post-treatment is a process consisting of two processes: a biogas acquisition process and a process of obtaining a dried treatment residue that has been subjected to a hydrothermal reaction suitable for biomass power generation from the dried treatment residue.

[0049] In this process, biogas recovery treatment can be performed by the biogas recovery system described below.

[0050] The biogas recovery device 60 is provided close to the vertical dry methane fermentation device 12. The biogas recovery device 60 has a function as a gas holder and is connected to the upper part of the methane fermentation tank 21 of the vertical dry methane fermentation device 12.

[0051] Biogas is drawn from the upper part of the methane fermentation tank 21 and recovered by the biogas recovery device 60.

[0052] The biogas recovered by the biogas recovery device 60 is purified. The biogas is led to the desulfurization tower 61, and hydrogen sulfide, which is a harmful component, is removed in the desulfurization tower 61.

[0053] The biogas is led to a regeneration device 62 such as a power generation facility and utilized as a high-calorie resource.

[0054] A high-efficiency methane fermentation method is adopted in the vertical dry anaerobic methane fermentation tank, and a biogas acquisition method is configured in which high-efficiency methane fermentation is carried out using a waste raw material with increased calorie content in the pretreatment to increase the biogas acquisition amount.

[0055] The semi-carbonized pellet forming treatment is a process that includes a semi-carbonized pellet forming treatment system, hydrothermally treats the dried treatment residue, pulverizes it, and generates semi-carbonized pellets.

[0056] A semi-carbonized pellet forming system 54 is provided, which consists of a dried treatment residue recovery device 41, a hydrothermal reaction treatment device 50 that receives the dried treatment residue from the dried treatment residue recovery device 41, hydrothermally treats the dried treatment residue, and generates a semi-carbonized powder product in a semi-carbonized powder state, a semi-carbonized powder product recovery device 51 that recovers the generated semi-carbonized powder product, and a semi-carbonized pellet generation device 52 that generates semi-carbonized pellets from the semi-carbonized powder product.

[0057] The dried treatment residue is drawn from the lower part of the methane fermentation tank 21 and recovered by the dried treatment residue recovery device 41. The recovered dried treatment residue is led from the dried treatment residue recovery device 41 to the hydrothermal reaction treatment device 50. It is recovered from the hydrothermal reaction treatment device 50 to the dried treatment residue recovery device 51.

[0058] The hydrothermal reaction treatment apparatus 50 is configured to include a cylindrical container 50A, a stirring means 50B disposed within the cylindrical container, and a boiler 50C having a superheating means. The waste raw material is hydrothermally reacted by the steam sent out from the boiler 50C, further crushed into powder, and semi-carbonized.

[0059] It is led to a pulverized and semi-carbonized, high-calorie powder acquisition device 51, and the generation of pulverized and semi-carbonized, high-calorie powder is obtained. This high-calorie powder product is mainly formed of pulverized and semi-carbonized high-calorie organic substances.

[0060] This powder product is led to a pellet generation device 52 and pelletized. In this way, using the hydrothermal reaction treatment apparatus 50, pulverized and semi-carbonized high-calorie organic substances can be generated, and pellets can be generated from the pulverized and semi-carbonized high-calorie organic substances.

[0061] The generated pellets are used as biomass power generation fuel in a biomass power generation device 53. The treated residue after collecting biogas is effectively utilized as biomass power generation fuel without being discarded. In this example, the dried treatment residue drawn from the lower part of the methane fermentation tank 21 is recovered as semi-carbonized powder by the semi-carbonized powder product recovery device 51. The whole amount of the recovered dried treatment residue, which is semi-carbonized powder, is subjected to a semi-carbonized pellet forming process in a semi-carbonized pellet forming system 54.

[0062] Part of the semi-carbonized powder, which is the dried treatment residue, may be led to the conveyor 9 for B pretreatment and subjected to methane fermentation treatment again in the C fermentation treatment to increase the amount of fermented methane gas. However, it is recommended that the whole amount of the semi-carbonized powder, which is the dried treatment residue, be subjected to a semi-carbonized pellet forming process in the semi-carbonized pellet forming system 54.

[0063] The regenerated biomass gas and biomass pellets can be used as electricity by external facilities or sold to power companies through gas turbines, gas engines, fuel cells, etc. In addition, they can be used for absorption chillers and heaters through boilers. The regenerated biomass gas and biomass pellets can also be used as raw materials for green hydrogen production devices.

[0064] In this way, in forming a recycling-oriented society, by adopting a high-efficiency methane fermentation method in a vertical dry anaerobic methane fermentation tank and using waste raw materials with increased calorie content in the pretreatment to perform high-efficiency methane fermentation to collect biogas, it is possible to efficiently and effectively utilize the treated residue after collecting the biogas in the post-treatment.

[0065] Figure 2 is a diagram showing the layout relationship between the vertical dry methane fermentation device and the biogas recovery device adopted in this embodiment.

[0066] The biomass gas recovery device 60 is arranged on the inner circular line 71 drawn with the center O as the center inside the circular line 70 that divides the central part.

[0067] On the circular line 72 that can be drawn outside the inner circular line 71, a plurality of vertical dry methane fermentation devices 12 are arranged in connection with each other, and the biomass gas generated by the plurality of vertical dry methane fermentation devices 12 is recovered by the biomass gas recovery device 60 arranged in the central part.

[0068] Figure 2 shows four biomass gas recovery devices 60 arranged in the central part and eight vertical dry methane fermentation devices 12 on the circular diameter line.

[0069] On the circular diameter line, a plurality of, typically four, biomass gas recovery devices 60 are arranged in connection with each other. The number of eight vertical dry methane fermentation devices 12 is twice the number of four biomass gas recovery devices 60. Biogas is taken out from two of the closest vertical dry methane fermentation devices to one biomass gas recovery device and connected to the connection path 64, and the biogas is recovered.

[0070] There may be only one biomass gas recovery device 60. In this case, eight vertical dry methane fermentation devices 12 are connected to one centrally arranged biomass gas recovery device 60 via the extraction connection path 64, and biogas is recovered. FIG. 3 is a diagram showing an example of the configuration of a hydrothermal reaction treatment apparatus used in an embodiment of the present invention.

[0071] In FIG. 3, the hydrothermal reaction treatment system includes a hydrothermal reaction treatment apparatus (i.e., a subcritical water reaction apparatus), and is composed of a heat source system for supplying heat, a treatment raw material input system, a product discharge system, a solid forming treatment system, and a control device. The general hydrothermal reaction treatment system itself has a well-known configuration.

[0072] In an embodiment of the present invention, the hydrothermal reaction treatment apparatus 6 or 50 (the hydrothermal reaction treatment apparatus 6 is shown in FIG. 3) includes a pressure vessel (also called a reactor) 101. The pressure vessel 101 is connected to a boiler 102 used as a heat source system for supplying steam, connected to a pulverization means 103 for the treatment raw material used in the treatment raw material input system, and connected to a product extraction means 104 used in the product discharge system.

[0073] A control device 105 for controlling the temperature, pressure, and treatment time inside the pressure vessel is provided.

[0074] 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 disposed with a space on the inner wall of the outer cylindrical vessel 111. A stirrer 113 is provided in the space (inner space) 106 inside the inner cylindrical vessel.

[0075] The pressure vessel 101 is provided with lids 114 and 115 for closing at both ends. A drive motor 116 is provided on one side of one lid 115. The drive motor 116 is connected to a stirrer 113 having rotating blades.

[0076] An outer temperature sensor and an outer pressure sensor 121 that 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 that measure the temperature and pressure in the space (inner space) 106 of the inner cylindrical container 112, and a moisture sensor 123 that measures the moisture in the space of the inner cylindrical container 112 are provided. The temperature and pressure in the inner space 106 are measured, the moisture in the inner space 106 of the inner cylindrical container 112 is measured, and each measured value is transmitted to the control device 105 via an electronic circuit as a data signal. These signal data are recorded by the recording means of the control device 105. The measured moisture content is used for setting the control data of the semi-carbonization treatment time.

[0077] The pressure vessel 101 is provided with a steam discharge pipe 118 connected to the inner cylindrical container 112, and a discharge control valve 119 is provided in the steam discharge pipe 118. With this configuration, the water vapor in the inner space can be discharged to the outside. The pressure vessel 101 is provided with a charging hopper 125 connected to the inner cylindrical container 112, and a discharge port having a discharge pipe 126 connected to the inner cylindrical container 112. A discharge control valve 120 is provided in the discharge pipe 126. With this configuration, the semi-carbonized powder material (solid body) generated by using the hydrothermal reaction treatment can be discharged to the outside.

[0078] The pulverization means 103 receives the collected treatment raw material 131 (representing the waste raw material 1 in FIG. 1) and the collected medical waste 132, pulverizes the two collected wastes, and inputs the pulverized waste into the charging hopper 125. A control valve 138 is provided in the charging hopper 125, and the input of the treatment raw material 131 is controlled by the control device 105.

[0079] The pulverization operation of the pulverization means 103 is controlled by the control device 105 connected by an electronic circuit.

[0080] At the stage when the processing raw material 131 is collected, the type of the processing raw material is determined. In many cases, the determination of the type of the processing raw material is made by the processing raw material processor. By attaching photographing means (not shown) near the input hopper 125, comparing the video photograph with a reference video photograph, and providing a means (not shown) for determining the type of the processing raw material, it is possible to automatically determine the type of the processing raw material. The determination data is input to the control device 105.

[0081] The boiler 102 includes a steam supply path 133 that supplies the generated steam to the pressure vessel 101. A superheated steam generator 140 is provided in the steam supply path 133 to superheat the generated steam and supply it to the pressure vessel 101.

[0082] The steam supply path 133 branches into a branch path 134 that supplies superheated steam into the space between the outer cylindrical container 111 and the inner cylindrical container 112 and a branch path 135 that supplies steam into the space of the inner cylindrical container 112, and control valves 136 and 137 are installed in each branch path. 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. By providing the superheated steam generator 140, it is possible to increase the internal temperature, that is, the hydrothermal reaction treatment temperature, without being proportional to the pressure in the inner cylindrical container.

[0083] The hydrothermal reaction treatment device 50 includes an inlet for the processing raw material, a mechanism for equalizing the hydrothermal reaction, and an outlet for taking out the generated hydrothermal reaction semi-carbonized solid matter, and is composed of a pressure vessel, a heat source for the hydrothermal reaction treatment and heat treatment, and a control device for controlling the hydrothermal reaction treatment and heat treatment. The semi-carbonized powder is manufactured by the hydrothermal reaction treatment and heat treatment of the processing raw material.

[0084] The hydrothermal reaction treatment device 50 selectively includes a pulverizing means 103 for making the processing raw material into a powder-shaped powder processing raw material.

[0085] The pressure vessel is composed of an outer cylindrical container and an inner cylindrical container, and the inner space inside the inner cylindrical container and the outer space between the inner cylindrical container and the outer cylindrical container are partitioned by the inner cylindrical container.

[0086] The control means sets the hydrothermal reaction temperature in the subcritical reaction region of water in the hydrolysis treatment region under a predetermined pressure, and in the hydrolysis treatment region, the treatment raw material is hydrolyzed to form a hydrolyzed substance.

[0087] For example, water vapor is introduced into the inner space, and in the hydrothermal reaction region within a hydrothermal reaction temperature of 230 °C or less and a hydrothermal reaction pressure of 1.0 MPa or less, typically within a hydrothermal reaction pressure of 0.3 to 3.5 MPa, and a hydrolysis treatment region is formed by controlling the appropriately set hydrothermal reaction treatment time, and the powder treatment raw material is hydrolyzed to form a powdery hydrolyzed substance.

[0088] The introduction of water vapor into the inner space is stopped, and the water vapor in the inner space is discharged to the outside.

[0089] In the drying / semi-carbonization treatment region, under a predetermined pressure, the semi-carbonization treatment temperature obtained from the type of the treatment raw material and the calorific value multiple is set, and from the hydrolyzed substance, a semi-carbonized solid using a hydrothermal reaction treatment having a predetermined calorific value, having a predetermined calorific value with respect to the calorific value of wood chips, and having a moisture content of 2 to 20%, preferably 3 to 6% is generated.

[0090] For example, in the outer space, a drying / semi-carbonization treatment region with a carbonization temperature within 230 °C or more and within the hydrothermal reaction temperature and with the treatment time controlled is formed, and from the hydrolyzed substance, a hydrothermal reaction semi-carbonized pellet, typically a semi-carbonized pellet using a high calorific value hydrothermal reaction treatment, a dried / semi-carbonized and powdered hydrothermal reaction solid can be produced.

[0091] Regarding wood chips, those with a moisture content of 35 to 40% and a calorific value of the carbide of 3300 kcal / kg are widely known. In the present invention, when calculating the calorific value multiple, a wood chip with a calorific value of 3300 kcal / kg is used as the reference wood chip. From the analysis by the inventors, those with a water content of 40% and a calorific value of the carbide of 3300 kcal / kg were also confirmed.

[0092] According to the experiments of the inventors, by providing the semi-carbonized pellet formation system 54, it is confirmed that a semi-carbonized solid using a hydrothermal reaction treatment with a calorific value more than 1.25 times that of the wood chips with a water content of 35 - 40% and a calorific value of 3300 kcal / kg, which is dried and semi-carbonized to a moisture content of 3 - 6%, can be produced.

[0093] A drying and semi-carbonizing treatment region with a semi-carbonizing temperature within 230°C and controlled treatment time can be formed.

[0094] When the powdered particulate hydrothermal reaction semi-carbonized solid is obtained, a semi-carbonized pellet based on the hydrothermal reaction in a form in which the powdered particulate hydrothermal reaction semi-carbonized solids are aggregated can be formed, which is the semi-carbonized solid using the above-described hydrothermal reaction treatment.

[0095] With the recovery 141 of the hydrothermal reaction semi-carbonized solid, detoxification and volume reduction 142 of harmful substances are carried out.

[0096] Thus, · High calorific value resource utilization: Production of a hydrothermal reaction semi-carbonized solid having a calorific value multiple of 1.25, desirably 1.5 or more, with respect to the calorific value of the wood chips · Suppression of carbon dioxide, dioxin, and odor is achieved.

[0097] In this embodiment, in FIG. 1, the hydrothermal reaction treatment device 6 is used. The configuration of the hydrothermal reaction treatment device 6 shown in FIG. 3 is substantially the same as the configuration of the above-described hydrothermal reaction treatment device 6. In this case, the treatment raw material 131 is read as the drying treatment residue 131. Also, the pulverization means 103 and the medical waste 132 do not need to be provided.

[0098] FIG. 4 is a diagram showing the relationship between the semi-carbonizing treatment temperature and the calorific value in the semi-carbonizing calorific value peak zone of the wood chips in the X - Y axis coordinates.

[0099] When the semi-carbonization treatment temperature was 25°C at room temperature, calorific value data with a calorific value of 3300 kcal and a calorific multiple of 1.0 was obtained. When exceeding room temperature, a calorific multiple with a calorific multiple of 1.0 (excluding 1.0) can be obtained at the semi-carbonization treatment temperature. When the semi-carbonization treatment temperature was 200°C, calorific value data with a peak calorific value of 5330 kcal and a calorific multiple of 1.62 was obtained. As shown in the figure, a semi-carbonization calorific value peak zone can be set. In the case of the treatment raw material becoming wood chips, a semi-carbonization calorific value peak zone with a semi-carbonization treatment temperature (°C) of 180 to 230 can be set. In the treatment in this zone, calorific value data with a maximum calorific value of 5330 kcal and a calorific multiple of 1.5 or more can be obtained.

[0100] Similarly, a semi-carbonization calorific value peak zone can be set for other treatment raw materials.

[0101] A method is proposed to produce semi-carbonized pellets with a moisture content semi-carbonized to 3 to 6% from the hydrothermal reaction treatment residue derived from the hydrothermal reaction treatment device connected to the downstream side of the vertical dry methane fermentation device, and having a calorific multiple of 1.5 times or more compared to the calorific value of the wood chips of the reference raw material of 3,300 kcal.

Explanation of symbols

[0102] 100... Biomass gas plant, 1... Waste raw material, 2... Waste raw material input, 3... Adjuster, 4... Sorter, 5... Flyer, 6... Hydrothermal reaction treatment device (subcritical water reaction device), 11... Boiler, 12... Vertical dry methane fermentation device, 21... Methane fermentation tank, 22... Stirrer disposed in the methane fermentation tank, 23... Driving device 23, 34... Hot air generator, 35... Heat preservation jacket, 41... Dry treatment residue recovery device (treatment residue discharge means), 50... Hydrothermal reaction treatment device, 51... High-calorie powder acquisition device, 52... Pellet production device, 53... Biomass power generation device, 54... Semi-carbonized pellet formation system, 60... Biogas recovery device (methane gas recovery device), 61... Desulfurization tower, 62... Regenerator, 64... Extraction connection path, 70... Circular line partitioning the central part, 71 Inner circular line, 72... Outer circular line.

Claims

1. A biomass gas plant including a waste material receiving device for receiving waste materials such as household waste, food residues, livestock manure, and plant residues, a pretreatment device for performing high-energy processing of the waste materials in a pretreatment before feeding into a methane fermentation tank, a vertical dry methane fermentation device equipped with a methane fermentation tank in which the pretreated waste materials are fed and fermented into methane, a biomass gas recovery device for recovering biomass gas containing fermented methane gas, and a drying treatment residue recovery device for recovering a drying treatment residue after the biomass gas recovery, A semi-carbonized pellet forming system is provided, which includes a drying residue recovery device, a hydrothermal reaction treatment device which receives the drying residue from the drying residue recovery device and hydrothermally treats the drying residue to generate a semi-carbonized powder product by semi-carbonization, a semi-carbonized powder product recovery device which recovers the generated semi-carbonized powder product, and a semi-carbonized pellet generating device which generates semi-carbonized pellets from the semi-carbonized powder product. A biomass gas plant characterized by:

2. The biomass gas plant according to claim 1, A fryer for frying the waste material with oil or a hydrothermal reaction treatment device for hydrothermal reaction treatment of the waste material is provided on the upstream side of the vertical dry methane fermentation device, and the waste material is fried by the fryer or hydrothermal reaction treatment by the hydrothermal reaction treatment device. A biomass gas plant characterized by:

3. The biomass gas plant according to claim 1, A fryer for frying waste materials with oily components and a hydrothermal reaction treatment device for hydrothermal reaction treatment of the waste materials are provided, and the waste materials fried in the fryer are fed into the hydrothermal reaction treatment device for hydrothermal reaction treatment and then fed into the biomass gas recovery device, or the waste materials hydrothermally treated in the hydrothermal reaction treatment device are fed into the fryer, fried in waste oil, and then fed into the biomass gas recovery device. A biomass gas plant characterized by:

4. The biomass gas plant according to claim 1, A biomass gas recovery device is arranged in the center, and a plurality of vertical dry methane fermentation devices are arranged in a connected manner on a circular line that can be drawn on the outside, and biomass gas generated in the plurality of vertical dry methane fermentation devices is recovered in the biomass gas recovery device arranged in the center. A biomass gas plant characterized by:

5. The biomass gas plant according to claim 4, A plurality of biomass gas recovery devices are arranged adjacent to each other on the circular diameter line, the number of vertical dry methane fermentation devices is twice the number of biomass gas recovery devices, and biomass gas is recovered from the two vertical dry methane fermentation devices to the one biomass gas recovery device closest to the two vertical dry methane fermentation devices. A biomass gas plant characterized by:

6. A method for generating biomass gas using a biomass gas plant including a waste material receiving device for receiving waste material such as household waste, food residues, livestock manure, and plant residues, a pretreatment device for performing high-energy treatment of the waste material in pretreatment before feeding into a methane fermentation tank, a vertical dry methane fermentation device equipped with a methane fermentation tank in which the pretreated waste material is fed and methane fermented, a biomass gas recovery device for recovering biomass gas containing fermented methane gas, a treatment residue recovery device for recovering treatment residue after recovery of the biomass gas, and a hydrothermal reaction treatment device for subjecting the treatment residue to hydrothermal reaction treatment in post-treatment of the treatment residue recovery device to powderization, The drying residue is collected, the drying residue is received, the drying residue is subjected to hydrothermal reaction to produce a semi-carbonized powder product, the produced semi-carbonized powder product is collected, and semi-carbonized pellets are produced from the semi-carbonized powder product, so as to semi-carbonize the entire amount of the collected drying residue into semi-carbonized pellets. A method for producing biomass gas using a biomass gas plant comprising the steps of:

7. This method produces semi-carbonized pellets, which are semi-carbonized to a moisture content of 3-6% from hydrothermal reaction residue extracted from a hydrothermal reaction treatment device connected to the downstream side of a vertical dry methane fermentation device, and have a calorific value that is 1.5 times or more higher than the calorific value of a standard raw material, wood chips, with 3,300 kcal.

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