Method and system for manufacturing fuel pellet

Abstract

To not only produce combustion pellets having a large calorific value from a biomass raw material but also contribute to the effective utilization of plastic waste and cost reduction.SOLUTION: The fuel pellet manufacturing system for manufacturing the fuel pellet from a biomass feedstock W1 is provided with a manufacturing system 10 for manufacturing a fuel pellet W7 (W12) by pellet-forming a mixture W4 (W10) obtained by mixing a plastic waste W2 with a semi-carbonized product of the biomass feedstock W1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and system for producing fuel pellets, and more particularly to fuel pellets produced from biomass raw materials. [Background technology]

[0002] Today, one of the major environmental pollution problems on Earth is global warming caused by the generation of carbon dioxide from fossil fuels. For this reason, as part of measures to combat global warming, efforts are being made to reduce the use of fossil fuels, which cause global warming, and to use new and renewable energy sources. One such new and renewable energy source is the method of producing fuel from biomass raw materials.

[0003] Fuels made from biomass materials emit less carbon dioxide than fossil fuels. In addition, the carbon dioxide emitted from biomass materials is offset by the CO2 emitted during combustion because the biomass materials absorbed CO2 through photosynthesis when they were plants, so biomass fuels are considered to emit no CO2 when used (so-called carbon neutral).

[0004] A typical example of biomass raw material is wood, such as thinned wood, which is pelletized to produce fuel pellets. For example, Patent Document 1 discloses that biomass raw material is compressed, volatile components are removed from the compressed material, and then the compressed material is semi-carbonized to produce semi-carbonized material. The semi-carbonized material is then pulverized, and a combustion additive and a binder are added to the pulverized material, followed by pelletizing to produce black pellets (a type of fuel pellet made from biomass raw material). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2024-13192 Summary of the Invention [Problem to be solved by the invention]

[0006] However, fuel pellets made from biomass raw materials have a calorific value that is only about 1 / 2 to 2 / 3 that of fossil fuels (such as coal), which is inferior in calorific value.Furthermore, combustion pellets made from biomass raw materials have the problem of being more expensive than fossil fuels.

[0007] Meanwhile, alongside the aforementioned global warming, another major environmental pollution problem is the pollution of the marine environment by plastic waste, raising the question of how to collect and dispose of this plastic waste. Generally, clean plastic is recycled or purchased for a valuable product, while contaminated plastic is incinerated or disposed of in a landfill.

[0008] However, when plastic is incinerated, it generates 5 to 12 times the heat generated by burning biomass materials, making it impossible to dispose of in existing general incineration facilities. For this reason, it is common to outsource the disposal to industrial waste disposal companies, which can be a burden.

[0009] Given this background, there is a need to create new value through the effective use of plastic waste.

[0010] The present invention has been made in consideration of the above circumstances, and aims to provide a method and system for producing fuel pellets that can not only produce combustion pellets with high calorific value from biomass raw materials, but also contribute to the effective use of plastic waste and reduction of fuel pellet costs. [Means for solving the problem]

[0011] In order to achieve the object, the fuel pellet manufacturing method of the present invention is a method for manufacturing fuel pellets from biomass raw materials, characterized in that the fuel pellets are manufactured by pelletizing a mixture of semi-carbonized biomass raw materials and plastic waste.

[0012] This not only improves the fuel quality of biomass raw materials, which have the problem of having a lower calorific value than fossil fuels, but also contributes to the effective use of plastic waste and cost reduction.

[0013] In an embodiment of the fuel pellet manufacturing method of the present invention, the plastic waste is preferably plastic composed only of carbon and hydrogen or only of carbon, hydrogen, and oxygen. Plastics composed only of carbon and hydrogen or only of carbon, hydrogen, and oxygen only generate water and carbon dioxide when burned, and do not generate harmful substances like plastics containing chlorine. Therefore, they are suitable as plastic waste to be mixed with biomass raw materials.

[0014] In a preferred embodiment of the fuel pellet manufacturing method of the present invention, the biomass raw material is livestock manure and the plastic waste is wrap film for roll bales. Both livestock manure and wrap film for roll bales are industrial waste that the livestock industry disposes of at its disposal cost, and making effective use of both of these materials is of great benefit to the livestock industry.

[0015] In order to achieve the above-mentioned objective, the fuel pellet manufacturing system of the present invention is characterized by comprising a fuel pellet manufacturing system that produces fuel pellets from biomass raw materials, and that produces fuel pellets by pelletizing a mixture of semi-carbonized biomass raw materials and plastic waste.

[0016] The above-mentioned method for manufacturing fuel pellets is regarded as an apparatus invention, and can obtain the same effects as a method invention.

[0017] In one embodiment of the fuel pellet manufacturing system of the present invention, the fuel pellets are a mixture of semi-carbonized biomass raw material and semi-carbonized plastic waste, and the system preferably includes a mixing device that mixes the biomass raw material with the plastic waste to produce a mixture, a semi-carbonized material manufacturing device that pyrolyzes the mixture in an anaerobic environment to produce a composite semi-carbonized material in which the semi-carbonized material resulting from the pyrolysis of the biomass raw material is mixed with the semi-carbonized material resulting from the pyrolysis of the plastic waste and pyrolysis oil, a crushing device that crushes the composite semi-carbonized material to produce pulverized material for pellets, and a pellet molding device that molds the pulverized material for pellets to produce pellets.

[0018] In this embodiment, the torrefied biomass material is mixed with the torrefied plastic waste to produce fuel pellets. In this way, a mixture of biomass material and plastic waste is torrefied, and fuel pellets are produced from a composite torrefied product, in which the torrefied product from the pyrolysis of the biomass material is mixed with the torrefied product from the pyrolysis of the plastic waste and pyrolysis oil. This not only increases the calorific value of fuel pellets made from biomass material, but also contributes to cost reduction and the effective use of plastic waste. Furthermore, the torrefied product from the pyrolysis of the plastic waste and the pyrolysis oil serve as a combustion promoter and a binder during pellet molding.

[0019] In one embodiment of the fuel pellet manufacturing system of the present invention, the fuel pellets are a mixture of semi-carbonized biomass raw material and semi-carbonized plastic waste, and the system preferably includes a semi-carbonized product manufacturing device that pyrolyzes the biomass raw material in an anaerobic environment to produce semi-carbonized biomass raw material, a mixing device that mixes semi-carbonized biomass raw material with semi-carbonized plastic waste to produce a semi-carbonized plastic mixture, a crushing device that crushes the semi-carbonized plastic mixture to produce crushed material for pellets, and a pellet molding device that molds the crushed material for pellets to produce pellets.

[0020] In this embodiment, semi-carbonized biomass raw material is mixed with semi-carbonized plastic waste to form fuel pellets.

[0021] Here, the term "unsemicarbonized plastic waste" refers to plastic waste that has not been treated in any way.

[0022] A preferred embodiment of the fuel pellet manufacturing system of the present invention includes a crushing device that crushes biomass raw materials and / or plastic waste into fragments to produce crushed material. In this way, by crushing biomass raw materials and / or plastic waste into fragments and mixing the crushed material in a mixer, it is possible to mix them evenly and uniformly. This makes it possible to ensure consistent quality of the fuel pellets that are ultimately manufactured.

[0023] Here, the reason why biomass raw materials and / or plastic waste are used is that it is possible that there may be fine biomass raw materials and plastic waste that do not need to be crushed.

[0024] In an embodiment of the fuel pellet manufacturing system of the present invention, the crushing device preferably crushes plastic waste into flakes and biomass raw materials into chips, which makes it easier to uniformly torrefy the biomass raw materials and plastic waste in a mixture of plastic waste with a high torrefying temperature and biomass raw materials with a lower torrefying temperature than the plastic waste.

[0025] In the fuel pellet manufacturing system of the present invention, the pellet molding device is preferably a single-screw or twin-screw extruder. Because extruder-type pellet molding devices can compress and knead in a heated state, they are suitable for pelletizing biomass raw materials and plastic waste, which are made of different materials and have different physical properties. In particular, they are suitable for pelletizing semi-carbonized biomass raw materials mixed with semi-carbonized plastic waste, which is difficult to pelletize.

[0026] In an embodiment of the fuel pellet manufacturing system of the present invention, the semi-carbide manufacturing device is preferably an externally heated screw conveyor type, which allows semi-carbide of consistent quality to be manufactured. In addition, a preferred embodiment of the fuel pellet of the present invention comprises torrefied biomass fuel and plastic waste or torrefied plastic waste. [Effects of the Invention]

[0027] The fuel pellet manufacturing method and manufacturing system of the present invention not only makes it possible to manufacture combustion pellets with a high calorific value from biomass raw materials, but also contributes to the effective use of plastic waste and reduction of fuel pellet costs. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a flow diagram showing the overall configuration of a fuel pellet manufacturing system according to a first embodiment of the present invention. [Figure 2] 1 is an explanatory diagram illustrating an example of a preferred structure of a crushing device, a mixing device, and a semi-carbide manufacturing device. [Figure 3] Partial cross-sectional side view of semi-carbide manufacturing equipment [Figure 4] A cross-sectional view showing a preferred example of a crushing device. [Figure 5] Side cross-sectional view of a single-screw extruder-type pellet molding device [Figure 6] A step flow diagram of a manufacturing method using the fuel pellet manufacturing system of the first embodiment of the present invention. [Figure 7] An explanatory diagram explaining a roll bale [Figure 8] FIG. 2 is a flow diagram showing the overall configuration of a fuel pellet manufacturing system according to a second embodiment of the present invention. [Figure 9] A step flow diagram of a manufacturing method using a fuel pellet manufacturing system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, preferred embodiments of the fuel pellet manufacturing method and manufacturing system of the present invention will be described with reference to the accompanying drawings.

[0030] The present invention is described by the following preferred embodiment. It is understood that many modifications can be made and other embodiments can be utilized without departing from the scope of the present invention. Therefore, all modifications within the scope of the present invention are included within the scope of the appended claims. In the drawings, parts denoted by the same symbols represent similar elements having similar functions. Furthermore, in this specification, when a numerical range is expressed using " to " (or "from" instead of " to "), the upper and lower limit numerical values ​​indicated by " to " (or "from") are also included in the numerical range.

[0031] [First embodiment of fuel pellet manufacturing system] The fuel pellet manufacturing system of the first embodiment is a case in which fuel pellets are manufactured by pelletizing a composite mixture obtained by mixing torrefied biomass raw material with torrefied plastic waste.

[0032] Fig. 1 is a schematic diagram of the equipment flow showing the overall configuration of the fuel pellet manufacturing system of the present invention according to the first embodiment. Therefore, only the names of the equipment will be explained in Fig. 1, and the structure will be explained using Figs. 2 to 6.

[0033] 1, the fuel pellet production system 10 of the first embodiment is mainly composed of a crushing device 12 that crushes biomass material W1 and / or plastic waste W2 into small fragments to produce crushed material W3, a mixing device 14 that mixes the crushed biomass material W1 with the crushed plastic waste W2 to produce a mixture W4, a semi-carbonized material production device 16 that pyrolyzes the mixture W4 under an anaerobic environment to produce a composite semi-carbonized material W5 that is a mixture of semi-carbonized material produced by pyrolysis of the biomass material W1, semi-carbonized material produced by pyrolysis of the plastic waste W2, and pyrolysis oil, a crushing device 18 that crushes the composite semi-carbonized material W5 to produce pellet-forming material W6, and a pellet molding device 20 that pelletizes the pellet-forming material W6 to produce fuel pellets W7, which are the final product of the present invention. The final product, fuel pellets W7, are stored in a storage container 21.

[0034] The reason for using biomass raw material W1 and / or plastic waste W2 is that it is possible that biomass raw material W1 or plastic waste W2 may be in the form of small fragments that do not need to be crushed.

[0035] The crushed material W3 produced by the crushing device 12 refers to the biomass raw material W1 and / or plastic waste W2 being crushed to a roughly crushed size, for example, a flake size (about 10 to 50 mm). The crushed material W6 for pellets produced by the crushing device 18 refers to the semi-carbonized material W5 being crushed to a powder size, for example, a particle size of 1 mm or less.

[0036] In the schematic diagram of the equipment flow in Figure 1, arrows indicate the products from the raw materials, biomass material W1 and plastic waste W2, to the final product, fuel pellets W7, so that the products produced in each device are clear.

[0037] Any renewable organic matter derived from plants or animals can be used as biomass raw material W1, but materials with low utility value or that would be disposed of, such as thinnings, wood waste from buildings, rice husks, livestock manure, and food waste, are suitable for use.

[0038] Furthermore, the type of plastic used as the plastic waste W2 is not important, but it is preferable to use plastic that decomposes into carbon dioxide and water when burned without generating harmful substances such as dioxins and chlorine gas.

[0039] The crusher 12 is provided upstream of the mixer 14 and is installed to crush the biomass raw material W1 and plastic waste W2 into fragment-like sizes to produce crushed material W3. Therefore, as described above, if the size does not require crushing, the crusher 12 can be omitted, but the fuel pellet manufacturing system 10 of the embodiment of the present invention will be described using an example in which the crusher 12 is used.

[0040] FIG. 2 is an explanatory diagram illustrating an example of a preferred structure of the crushing device 12, the mixing device 14, and the semi-carbide producing device 16.

[0041] (Crushing equipment) The crushing device 12 can be any device that can crush the biomass raw material W1 and plastic waste W2 into pieces of approximately flake size, but in this embodiment, we will explain the example of a crushing device 12 that uses a horizontal rotary blade.

[0042] 2, the horizontal rotary blade type crusher 12 is mainly composed of a plurality of rotating blades 22 and a plurality of fixed blades 24 corresponding to the rotating blades 22. The crusher 12 has a rotating shaft 28 provided in the axial direction of a cylindrical casing 26, one end of which is connected to a motor 30 and the other end of which is rotatably supported by a bearing 32.

[0043] The casing 26 is composed of a cylindrical large-diameter cylindrical section 26A and a cylindrical small-diameter cylindrical section 26B, and the large-diameter cylindrical section 26A and the small-diameter cylindrical section 26B are connected by a tapered cone-shaped connecting cylindrical section 26C. A hopper 34 is provided at the upper end of the large-diameter cylindrical section 26A of the casing 26, through which the biomass material W1 and / or plastic waste W2 to be crushed is introduced into the casing 26, and a discharge pipe 36 is provided at the lower end of the small-diameter cylindrical section 26B, through which the crushed biomass material W1 and / or plastic waste W2 are discharged as crushed material W3.

[0044] Furthermore, a plurality of large-diameter, disc-shaped rotating vanes 22 are provided at equal intervals on the large-diameter cylindrical portion 26A of the rotating shaft 28, and small-diameter, disc-shaped rotating vanes 22 are also provided at equal intervals on the small-diameter cylindrical portion 26B. A plurality of circular ring-shaped fixed vanes 24 corresponding to the rotating vanes 22 are fixed to the inner surfaces of the large-diameter cylindrical portion 26A and the small-diameter cylindrical portion 26B. The rotating vanes 22 rotate at high speed, generating a shear force between them and the fixed vanes 24. This crushes the biomass material W1 and / or plastic waste W2 into fragments to produce crushed material W3.

[0045] (mixing device) As shown in FIG. 2, the mixer 14 mixes the biomass material W1 and the crushed plastic waste W2 W3.

[0046] The mixing device 14 is mainly composed of a mixing tank 38 and an agitator 40. The mixing tank 38 is a rectangular container with an open top, and is preferably formed with a volume size corresponding to the amount to be processed in the subsequent semi-carbide manufacturing device 16.

[0047] The agitator 40 has a motor 40B attached to one end of an agitating rod 40A, and a plurality of agitating blades 40C attached at equal intervals to the tip of the agitating rod 40A.

[0048] It is preferable that crushed biomass material W3 be first added to the mixing tank 38, and then crushed plastic waste W2 W3 be added while the biomass material W1 is being stirred by the mixer 40. This allows for the production of a mixture W4 in which the biomass material W1 and the plastic waste W2 are mixed evenly and uniformly.

[0049] In the fuel pellet manufacturing system 10 of this embodiment, a crushing device 12 is provided in front of the mixing device 14 to break the biomass raw material W1 and / or plastic waste W2 into pieces that are easy to mix, so the mixing device 14 has a simple structure of a mixing tank 38 and an agitator 40, but this structure is not limited to this, and a mixing device that can both crush and mix can also be used.

[0050] (Hemi-carbide production equipment) The semi-carbonized material manufacturing device 16 can be any device that can pyrolyze the mixture W4 of biomass raw material W1 and plastic waste W2 in an anaerobic environment, but in this embodiment, an external heat / screw conveyor system will be described.

[0051] The semi-carbide manufacturing apparatus 16 shown in FIG. 2 is a partial cross-sectional view of the semi-carbide manufacturing apparatus 16 of an external heat / screw conveyor type as seen from the front, and FIG. 3 is a partial cross-sectional view of the semi-carbide manufacturing apparatus 16 as seen from the side.

[0052] As shown in Figures 2 and 3, the semi-carbide manufacturing apparatus 16 is mainly composed of a long, cylindrical conveyor tube 42, a screw feeder 44 installed inside the conveyor tube 42, a flue cover 46, a combustion furnace 48, and a semi-carbide discharge line 50.

[0053] The conveyor cylinder 42 is supported horizontally on a support frame 52 formed into a rectangular parallelepiped shape by a plurality of pipes. The support frame 52 is fixedly mounted on a base frame 54 so as not to move. A supply port 42A for supplying the mixture W4 is formed on the upper front surface of the peripheral surface of the conveyor cylinder 42, and a hopper 56 for introducing the mixture W4 is provided above the supply port 42A (see FIG. 3).

[0054] An open / close lid 56A is supported on the hopper 56 so as to be freely opened and closed, and when the mixture W4 is torrefied, the open / close lid 56A is closed to seal the inside of the conveyor cylinder 42. In addition, a connector 50D is formed on the rear lower surface of the circumferential surface of the conveyor cylinder 42 for connecting a discharge pipe 50E (see FIG. 2) through which the torrefied torrefied material W5 is discharged.

[0055] In addition, a pyrolysis gas exhaust pipe 58 for pyrolysis gas generated by the thermal decomposition of the mixture W4 is provided on the upper rear surface of the circumferential surface of the conveyor cylinder 42, and the pyrolysis gas exhaust pipe 58 is provided with a check valve 60 for preventing outside air from entering the inside of the conveyor cylinder 42. As a result, when the semi-carbonization process of the mixture W4 is performed, the inside of the conveyor cylinder 42 becomes an anaerobic environment that does not allow air to enter, in combination with the opening / closing lid 56A of the hopper 56 being closed.

[0056] The front side (or front end) of the conveyor cylinder 42 refers to the side of the supply port 42A of the conveyor cylinder 42, and the rear side (or rear end) refers to the side of the discharge port of the conveyor cylinder 42.

[0057] As shown in FIG. 3, the screw feeder 44 has a rotating shaft 44A arranged in the axial direction of the conveyor tube 42 and a spiral screw blade 44B attached to the rotating shaft 44A. The diameter of the screw blade 44B is formed to be as small as possible so as not to come into contact with the inner wall surface of the conveyor tube 42.

[0058] This allows the mixture W4 to be efficiently transported inside the conveyor cylinder 42, preventing the mixture W4 from adhering to the inner wall surface of the conveyor cylinder 42 and remaining there without being transported.

[0059] Both ends of the rotary shaft 44A of the screw feeder 44 are rotatably supported by a pair of bearings 62A, and one end of the rotary shaft 44A is connected to a stepless motor 64. As a result, when the stepless motor 64 is driven, the screw feeder 44 rotates to convey the mixture W4, and by adjusting the rotation speed, the conveying speed of the mixture W4, i.e., the torrefaction treatment speed, can be adjusted.

[0060] The flue cover 46 is a cover that is fitted to the outside of the conveyor cylinder 42 with a gap therebetween, and is formed in a cylindrical shape that is slightly larger than the conveyor cylinder 42. As a result, a flue 46A for the flue gas generated in the combustion furnace 48 is formed in the gap between the flue cover 46 and the conveyor cylinder 42. In addition, a chimney 66 is provided on the upper rear surface of the peripheral surface of the flue cover 46 to discharge the flue gas flowing through the flue 46A.

[0061] The combustion furnace 48 is mainly composed of a combustion can 48A and a combustion tray 48B placed at the bottom of the combustion can 48A, and an upper opening 48C of the combustion can 48A is connected to a flue inlet 46B formed on the central lower surface of the periphery of the flue cover 46. The flame from burning fuel in the combustion tray 48B directly heats the outside of the conveyor tube 42, and high-temperature smoke flows from the combustion can 48A through the flue inlet 46B into the flue 46A and is discharged from the chimney 66.

[0062] As a result, the combustion furnace 48 not only directly heats the conveyor tube 42, but also indirectly heats the entire conveyor tube 42 by the high-temperature exhaust gas flowing through the flue 46A. That is, the high-temperature exhaust gas generated by burning fuel in the combustion furnace 48 flows through the flue 46A and exchanges heat with the mixture W4 supplied inside the conveyor tube 42, thereby pyrolyzing the mixture W4.

[0063] In the torrefied material production apparatus 16 configured as described above, the mixture W4 is fed into the conveyor tube 42 from the supply port 42A via the hopper 56, and while being heated in an anaerobic environment lacking air (oxygen), it is slowly transported toward the discharge port by the rotation of the screw feeder 44. During transport, the mixture W4 is pyrolyzed and torrefied by the heat from the combustion furnace 48, producing a composite torrefied material W5 in which the torrefied biomass material W1 is mixed with the torrefied plastic waste W2 and pyrolysis oil. The produced composite torrefied material W5 is discharged into the torrefied material discharge line 50 when a sliding opening / closing lid (not shown) at the discharge port is opened.

[0064] The semi-carbide discharge line 50 is mainly composed of a discharge hopper 50A that receives the semi-carbide W5 discharged from the discharge outlet of the conveyor tube 42, a storage tank 50B that temporarily stores the composite semi-carbide W5, and a screw conveyor 50C that supplies the composite semi-carbide W5 to the combustion furnace 48.

[0065] The discharge hopper 50A is provided below the discharge outlet of the conveyor cylinder 42, and a rectangular storage tank 50B is provided below the discharge hopper 50A.

[0066] Furthermore, a connector 50D is provided at the bottom of one side of the rectangular storage tank 50B to detachably connect a discharge pipe 50E that supplies the stored composite semi-carbide W5 to the subsequent crushing device 18. Furthermore, a screw conveyor 50C is extended from the lower part of the side of the storage tank 50B on the combustion furnace 48 side to the combustion furnace 48. This allows the composite semi-carbide W5 stored in the storage tank 50B to be supplied to the crushing device 18, or as fuel for the combustion furnace 48 as needed.

[0067] Since the composite semi-carbonized material W5 has a larger calorific value than semi-carbonized material made only from biomass raw material W1, the fuel cost of the semi-carbonized material manufacturing device 16 can be reduced by supplying the composite semi-carbonized material W5 to the combustion furnace 48 using the screw conveyor 50C.

[0068] In addition, since the semi-carbonized material manufacturing apparatus 16 is a large and heavy device and the accumulation locations for various biomass raw materials W1 and plastic waste W2A are different, it is preferable that the semi-carbonized material manufacturing apparatus 16 be mounted on a cart 68 so that it can be moved.

[0069] The cart 68 is composed of a plate-shaped mounting base 68A on which the support frame 52 that supports the torrefied material production apparatus 16 is mounted, four wheels 68C provided at the four corners of the underside of the mounting base 68A and attached via rotation shafts 68B, and a connector 68D that detachably connects the mounting base 68A to a vehicle 70 such as a trailer. This allows the torrefied material production apparatus 16 mounted on the cart 68 to be moved to a required location, where the mixture W4 of the biomass raw material W1 and the plastic waste W2 can be torrefied.

[0070] Furthermore, when the mixer 14 is installed on the ground, the hopper 56 of the semi-carbide manufacturing apparatus 16 mounted on the cart 68 is located at a position much higher than a person's height. Therefore, it is necessary to provide a transport conveyor 72 (see FIG. 2) for transporting the mixture W4 mixed in the mixer 14 up to the height of the hopper 56 of the semi-carbide manufacturing apparatus 16.

[0071] As the transfer conveyor 72, it is preferable to use, for example, a transfer conveyor of the belt conveyor type.

[0072] The torrefied material production apparatus 16 is controlled by a control panel 74 (see FIG. 3) provided on the support frame 52. For example, to adjust the degree of pyrolysis of the mixture W4, the control panel 74 controls the stepless motor 64 and combustion furnace 48 of the torrefied material production apparatus 16 to adjust the rotation of the screw feeder 44 and the heating temperature of the conveyor tube 42. In order to torrefy the mixture W3 in which plastic waste W2 is mixed with biomass raw materials W1 having different torrefying temperatures, as in the present invention, it is important to adjust the heating state appropriately.

[0073] (Crushing equipment) 4A and 4B are cross-sectional views showing a preferred example of the crushing device 18, where (A) is a side cross-sectional view and (B) is a front cross-sectional view. Any device may be used as long as it can crush the material to a particle size that can be easily formed into pellets by the pellet forming device 20.

[0074] As shown in FIG. 4, the crushing device 18 is mainly composed of a casing 76, a rotor 80 having a rotary blade 78, and a fixed blade 82 formed on the inner surface of the casing 76.

[0075] The casing 76 is formed in a cylindrical shape with both ends closed. A hopper 84 is provided at the upper end of one end of the casing 76, into which composite semi-carbonized material W5 semi-carbonized in the semi-carbonized material manufacturing device is introduced, and a pulverized material discharge pipe 86 is provided at the lower end of the other end of the casing 76, through which pulverized material W6 for pellets crushed into powder in the crushing device 18 is discharged.

[0076] The rotor 80 has a rotary shaft 88 that passes through the center of the casing 76 in the longitudinal direction, and a cylindrical rotating portion 90 that is provided inside the casing 76, is supported by the rotary shaft 88, and rotates together with the rotary shaft 88. The cylindrical rotating portion 90 is formed to be slightly shorter than the longitudinal length of the casing 76. As shown in Figures 4A and 4B, the cylindrical rotating portion 90 has a circumferential surface on which a plurality of long rotary blades 78 are fixed at equal intervals around the cylindrical rotating portion 90 along the axial direction of the rotary shaft 88 (eight rotary blades 78 are shown in Figure 4).

[0077] The fixed blade 82 is formed in a file shape on the entire inner surface of the casing 76, and a small gap is formed between it and the blade portion of the rotor-type rotary blade 78. Both ends of the rotary shaft 88 are rotatably supported by a pair of bearings 92, and one end of the rotary shaft 88 is connected to a motor 94 that can rotate continuously.

[0078] As a result, the composite semi-carbide W5 supplied from the hopper 84 to the inside of the crushing device 18 is crushed into powder by the rotor-type rotary blade 78 rotating at high speed (for example, 3000 rpm) and the file-like fixed blade 82. This produces crushed material for pellets W6 that will be used to pelletize the composite semi-carbide W5 in the subsequent pellet molding device.

[0079] (Pellet molding equipment) The pellet molding device 20 may be any device that can mold the powder material W6 for pellets obtained by pulverizing the composite semi-carbide W5 into powder using the pulverizer 18 into pellet shape. In this embodiment, however, the pellet molding device 20 will be described as a single-screw extruder type, as shown in FIG. 5.

[0080] Furthermore, when stronger compression kneading than that achieved by a single screw is required in pellet molding, a twin-screw extruder type pellet molding device can also be used.

[0081] The single-screw extruder type pellet molding device 20 is mainly composed of a cylindrical cylinder 96, a screw 98 housed within the cylinder 96, a die 100 attached to the tip face of the cylinder 96, and a cutter 102 that cuts the rod-shaped product extruded from the die 100 to the length of pellets.

[0082] The screw 98 is connected to a rotation drive unit 104, and as the screw 98 rotates, the pulverized material for pellets W6 is conveyed in a compressed state to the die 100 side of the cylinder 96. The die 100 is also formed with a plurality of small discharge holes 100A, and the molded product molded in the pellet molding device 20 is discharged as a rod-shaped molded product from the plurality of discharge holes 100A.

[0083] In addition, a hopper 106 is provided at the top of the cylinder 96 on the opposite side from the die 100, which supplies pellet-forming crushed material W6 crushed into powder by the crushing device 18 into the cylinder 96, and the cylinder 96 has a built-in heating heater (not shown).

[0084] The cylinder 96 is divided into a supply section X that supplies the pellet-forming pulverized material W6 introduced into the hopper 106 into the cylinder 96 in fixed amounts, a compression section Y that compresses and kneads the supplied pellet-forming pulverized material W6, and a metering section Z that maintains a constant flow rate of the pellet-forming pulverized material W6 flowing inside the cylinder 96 and keeps the pressure inside the cylinder 96 constant.

[0085] Any type of cutter 102 may be used as long as it can cut the multiple pellet-shaped products extruded in a rod-like shape from the die 100 to the length of the pellet size, but in this embodiment, a guillotine-type cutter 102 will be described. The guillotine-type cutter 102 is composed of a guillotine blade 102A that moves up and down along the surface of the die 100, and a piston cylinder 102B that drives the guillotine blade 102A up and down. In this way, the rod-shaped products extruded from the die 100 are cut into pellet size by the cutter 102, and fuel pellets W7 are produced. The produced fuel pellets W7 are stored in the storage container 21.

[0086] Next, a process flow for manufacturing fuel pellets using the fuel pellet manufacturing system 10 of the first embodiment configured as described above will be described. 6 is a process flow diagram illustrating the method for producing fuel pellets. It will be easier to understand by also referring to the apparatus flow in FIG. 1 described above.

[0087] As shown in Figures 1 and 6, the fuel pellet manufacturing method mainly consists of step 1, a crushing process (S1), step 2, a mixing process (S2), step 3, a semi-carbide manufacturing process (S3), step 4, a pulverizing process (S4), and step 5, a pellet forming process (S5).

[0088] In the embodiment of the present invention, an example of biomass material W1 and plastic waste W2 generated in the livestock industry will be described. Specifically, livestock manure W1A was used as the biomass material W1, and wrap film W2A for roll bales used for transporting and storing livestock feed was used as the plastic waste W2.

[0089] FIG. 7 is an explanatory diagram illustrating the round bale 108. As shown in Figure 7, a roll bale 108 is made by compressing and rolling up livestock feed (roughage) such as corn for storage or harvested grass into a cylindrical shape, and then wrapping it in roll bale wrap film W2A. Most Japanese roll bales 108 are around 120 cm to 155 cm in diameter, while roll bales 108 overseas can have diameters of 155 cm or more. A 120 cm diameter roll bale 108 can weigh approximately 350 kg for dry grass (about 15% moisture) or approximately 450 kg for silage (about 50% moisture).

[0090] Traditionally, in the livestock industry, hay and straw harvested from summer to autumn are dried to produce hay, and silage made by lactic acid fermentation of this hay is formed and stored to be used as winter feed for livestock. While used roll bale wrap film W2A is generally disposed of at a cost, making effective use of roll bale wrap film W2A offers significant benefits to the livestock industry.

[0091] The qualities required for wrap film W2A for roll bales include high puncture resistance (resistance to holes created by protruding objects such as stalks mixed in with the livestock feed that forms the roll bale 108) and airtightness (high stretchability), excellent film flexibility during wrapping (high elasticity), and resistance to deterioration by ultraviolet light, as roll bales may be stored outdoors. For these reasons, linear polyethylene, low-density polyethylene, ethylene vinyl acetate, and multi-layered versions of these plastics are commonly used. These plastics are composed solely of carbon and hydrogen or carbon, hydrogen, and oxygen. This allows them to decompose into carbon dioxide and water when burned. Therefore, even when burned as fuel, they do not produce harmful substances such as dioxins, unlike chlorine-containing plastics, making them suitable for plastic waste W2.

[0092] In the method for producing fuel pellets, first, in the crushing step S1 of step 1, livestock manure W1A as a biomass raw material does not need to be crushed, so wrap film for roll bales W2A is crushed into small pieces by a crusher 12.

[0093] In the case of the horizontal rotary blade type crusher 12 shown in Figure 2, wrap film W2A for round bales fed from the hopper 34 into the large diameter cylindrical section 26A is first roughly crushed by the shearing action of the rapidly rotating rotary blades 22 and fixed blades 24. It is then sent under pressure to the small diameter cylindrical section 26B by the cone-shaped connecting cylindrical section 26C, where it is crushed into pieces by the rotary blades 22 and fixed blades 24. The crushed wrap film W2A for round bales falls into the subsequent mixer 14 through the discharge pipe 36.

[0094] As described above, the roll bale 108 has a diameter of about 120 cm to 155 cm, and the wrap film W2A for roll bales is also wide and long. Therefore, it is preferable to cut it into a size that can be easily fed into the crusher 12 in advance.

[0095] Next, in the mixing process S2 of step 2, livestock manure W1A is placed in advance in the mixing tank 38 of the mixer 14. In this case, an amount of livestock manure W1A sufficient for one batch of the semi-carbonized material production process S3 of the next step 3 is placed in the mixing tank 38. Then, while the livestock manure W1A in the mixing tank 38 is being stirred by the agitator 40, flake-sized wrap film W2A for roll bales, which has been crushed into flake size by the crusher 12, is gradually added to the mixing tank 38. This makes it possible to produce a mixture W4 in which the wrap film W2A for roll bales is evenly mixed throughout the livestock manure W1A.

[0096] Next, in the semi-carbonized material production process S3 of step 3, a cart 68 equipped with the semi-carbonized material production device 16 is parked next to the mixer 14. Then, using the semi-carbonized material production device 16, a composite semi-carbonized material W5 is produced from the mixture W4 produced in the mixing tank 38, in which semi-carbonized material produced by pyrolysis of livestock manure W1A is mixed with semi-carbonized material produced by pyrolysis of wrap film W2A for roll bales and pyrolysis oil.

[0097] That is, as shown in Figures 2 and 3, the mixture W4 produced in the mixing tank 38 is fed into the hopper 56 of the semi-carbide production device 16 by a belt conveyor type transport conveyor 72 (see Figure 3) and supplied into the conveyor cylinder 42.

[0098] Once the mixture W4 has been supplied into the conveyor tube 42, the open / close lid 56A of the hopper 56 is closed. This, coupled with the check valve 60 provided in the dry distillation gas exhaust pipe 58, creates an anaerobic environment inside the conveyor tube 42, preventing air from entering. In addition, the conveyor tube 42 is directly heated by the combustion furnace 48, and high-temperature exhaust gas generated by the combustion furnace 48 is sent into the flue 46A, heating the inside of the conveyor tube 42 from the outside.

[0099] As a result, the mixture W4 supplied to the inside of the conveyor tube 42 is heated in an anaerobic environment while being transported by the screw feeder 44. As a result, water evaporates from the mixture W4 and volatile compounds are removed. When the mixture W4 is further heated, a pyrolysis reaction occurs, converting it into a semi-carbonized material with a high carbon content without burning. That is, the livestock manure W1A is pyrolyzed into a semi-carbonized material, and the roll bale wrap film W2A is pyrolyzed into a semi-carbonized material and pyrolysis oil. The composite semi-carbonized material W5, which is a mixture of the semi-carbonized livestock manure W1A produced in this way, the semi-carbonized roll bale wrap film W2A, and pyrolysis oil, has a significantly greater calorific value than semi-carbonized livestock manure W1A alone.

[0100] In this case, as in this embodiment, an external heat / screw conveyor type semi-carbide production apparatus 16 is employed, and the mixture W4 is heated while being conveyed by the screw feeder 44. This allows the semi-carbide produced by pyrolysis of the livestock manure W1A to be uniformly mixed with the semi-carbide produced by pyrolysis of the roll bale wrap film W2A and pyrolysis oil, thereby producing homogeneous fuel pellets with a large calorific value when processed into the final product, fuel pellets W7. The produced composite semi-carbide W6 is then stored in the storage tank 50B of the semi-carbide discharge line 50.

[0101] The semi-carbide manufacturing apparatus 16 in this embodiment is provided with a screw conveyor 50C that supplies the composite semi-carbide W5 to the combustion furnace 48, so that part of the composite semi-carbide W5, which has a large calorific value and is stored in the storage tank 50B, can be used as fuel for the combustion furnace 48. This results in a larger calorific value than when semi-carbide made of only the biomass raw material W1 is supplied to the combustion furnace 48, and therefore the fuel cost of the semi-carbide manufacturing apparatus 16 can be reduced.

[0102] Incidentally, the torrefaction temperature at which biomass raw material W1 such as livestock manure W1A is torrefied by pyrolysis is generally 200°C to 300°C, but the torrefaction temperature at which plastic waste W2 such as wrap film for roll bales W2A mixed into mixture W4 is torrefied by pyrolysis is approximately 300°C to 400°C.

[0103] Therefore, it is considered preferable to set the heating temperature of the semi-carbonized material manufacturing device 16 to around 300°C, but as described below, it is preferable to find appropriate semi-carbonization conditions through testing, etc., taking into account the mixing ratio of the wrap film W2A for roll bales to the livestock manure W1A.

[0104] In this case, taking into consideration the problem of an increase in the calorific value of the fuel pellets W7, it is preferable to increase the mixing ratio of flakes of wrap film W2A for roll bales to livestock manure W1A in the mixture W4 that is semi-carbonized in the semi-carbonized material manufacturing apparatus 16, from the viewpoint of increasing the calorific value of the fuel pellets W7 that are ultimately produced.

[0105] However, if the mixing ratio of flakes in the wrap film W2A for roll bales is too high, there is a risk that the livestock manure W1A in the mixture W4 will be carbonized beyond semi-carbonization at the semi-carbonization temperature of approximately 300°C, or conversely, the wrap film W2A for roll bales in the mixture W4 will be processed without being sufficiently semi-carbonized.

[0106] On the other hand, if the mixing ratio of the wrap film W2A for roll bales is too small, the effect of achieving the object of the present invention of increasing the calorific value of the fuel pellets W7 will be reduced.

[0107] Thus, it is believed that the semi-carbonization conditions in the semi-carbonized material manufacturing apparatus 16 and the mixing ratio of flakes of the wrap film W2A for roll bales to the livestock manure W1A have a significant impact on the production of a high-quality composite semi-carbonized material.

[0108] Therefore, in terms of the semi-carbonization conditions in the semi-carbonized material manufacturing apparatus 16, it is preferable to examine the following points through tests, etc., in order to semi-carbonize the livestock manure W1A and the wrap film W2A for roll bales in the mixture W3 as evenly as possible.

[0109] (A) When the semi-carbonization temperature of the mixture W3 in the semi-carbonized material manufacturing device 16 is set constant within the range of 200°C to 400°C, the ratio of the mixing ratio of the wrap film W2A for roll bales to the livestock manure W1A is changed to investigate the relationship between the semi-carbonization temperature and the mixing ratio.

[0110] (B) Conversely, when the mixing ratio of mixture W3 in the semi-carbonized material manufacturing apparatus 16 is set constant, the semi-carbonization temperature is changed within the range of 200°C to 400°C to investigate the relationship between the mixing ratio and the semi-carbonization temperature.

[0111] (C) In (A) and (B) above, the relationship between the mixing ratio and the semi-carbonization temperature is investigated when the conveying speed (semi-carbonization treatment time) of the mixture W4 in the conveyor tube 42 by the screw feeder 44 is changed.

[0112] (D) In ​​the above (A), (B) and (C), the moisture content of the livestock manure W1A when producing the mixture W4 is changed, and the relationship between the mixing ratio and the semi-carbonization temperature is investigated.

[0113] (E) In the crusher 12, the wrap film W2A for roll bales is crushed into flakes and the livestock manure W1A is crushed into chips, and these are mixed in the mixer 14 to produce a mixture W3. This takes advantage of the fact that flake-like wrap film W2A for roll bales, which is thinner than chip-like livestock manure W1A, is easier to torrefy. As a result, as described above, the mixture W3 of the wrap film W2A for roll bales, which has a high torrefying temperature, and the livestock manure W1A, which has a lower torrefying temperature, can be more easily torrefyed uniformly.

[0114] The above study has been explained using an example of livestock manure W1A and wrap film for roll bales W2A, but the same applies to other cases of biomass materials W1 and plastic waste W2.

[0115] Next, in the pulverization process S4 of step 4, the composite semi-carbide W5 produced in the semi-carbide production apparatus 16 is pulverized into powder by the pulverizer 18 to produce pulverized material for pellets W6. That is, the composite semi-carbide W6 fed into the casing 76 from the hopper 84 of the pulverizer 18 is pulverized into powder with a particle size of 1 mm or less by the strong impact generated by the rotor-type rotary blade 78 rotating at a high speed of, for example, about 3000 rpm and the file-like fixed blade 82. In this way, the pulverized material for pellets W6 to be used in the next step S5, the pellet molding process S5, is produced.

[0116] Next, in step 5, a pellet-forming process S5, the pulverized material W6 for pellets produced by the pulverizer 18 is formed into pellets by a single-screw extruder-type pellet molding device 20. Specifically, the powdered pulverized material W6 for pellets is fed into a hopper 106 of the pellet molding device 20. The pulverized material W6 for pellets fed into the hopper 106 is supplied to a supply section X in a cylinder 96. While being heated and melted by the heat from the cylinder 96 and the compression heat from the screw 98, the material is sent in this order to the supply section X, the compression section Y, and the metering section Z, and is extruded as rod-shaped pellets from a discharge hole 100A of a die 100. The rod-shaped pellets extruded from the die 100 are cut into pellet size by a cutter 102. This produces pellet-shaped fuel pellets W7. The produced fuel pellets W7 fall into a storage container 21 and are stored there.

[0117] According to the fuel pellet manufacturing method and manufacturing apparatus of the embodiment of the present invention, the following advantageous effects can be obtained.

[0118] (1) According to the fuel pellet manufacturing system 10 of the first embodiment of the present invention, a mixture W4 obtained by mixing biomass raw material W1 with plastic waste W2 was subjected to a semi-carbonization process, and fuel pellets were produced from a composite semi-carbonized product W5 obtained by mixing the semi-carbonized product obtained by pyrolysis of the biomass raw material W1 with the semi-carbonized product obtained by pyrolysis of the plastic waste W2 and pyrolysis oil.

[0119] Plastic waste W2 is derived from petroleum, and the calorific value of the semi-carbonized product obtained by pyrolysis of plastic waste W2 is higher than that of the semi-carbonized product obtained by pyrolysis of biomass raw material W1, and a calorific value approximately equivalent to that of coal, a fossil fuel, can be obtained.

[0120] Therefore, by mixing plastic waste W2 with biomass raw material W1, not only can the calorific value of the manufactured fuel pellets W7 be increased, but also plastic waste W2 that would otherwise be disposed of at a cost can be effectively utilized.

[0121] (2) In conventional technology, fuel pellets produced from biomass material W1 often use combustion accelerators and binders during pelletization. In contrast, in the present invention, the torrefied material and pyrolysis oil obtained when the plastic waste W2 mixed with the biomass material W1 is torrefied serve as combustion accelerators. Specifically, torrefying the plastic waste W2 removes as much moisture as possible and produces plastic with concentrated carbon components, resulting in a higher energy density (amount of energy per volume) than untorrefied plastic waste W2. Furthermore, the addition of pyrolysis oil not only further increases the energy density, but also serves as a binder (granulating agent) during pelletization. Therefore, in the present invention, combustion accelerators and binders conventionally used during pelletization can be eliminated or reduced in amount, thereby reducing the cost of producing fuel pellets W7.

[0122] (3) Furthermore, in the fuel pellet manufacturing system 10 according to the first embodiment of the present invention, both the biomass raw material W1 and the plastic waste W2 are semi-carbonized, and thus fuel pellets W7 having moisture-proof properties can be obtained by the moisture-regulating properties of the charcoal. That is, one of the properties of charcoal is that when excess moisture is supplied from the outside air, the charcoal decomposes the supplied excess moisture, a so-called "self-humidity-regulating property." This allows the fuel pellets W7 to remain moist during storage, making it possible to produce fuel pellets that are easy to burn. Semi-carbonization is particularly effective when using a biomass raw material W1 that easily absorbs moisture, such as wood.

[0123] In the first embodiment, the biomass material W1 is livestock manure W1A, and the plastic waste W2 is roll bale wrap film W2A. However, this is not limiting. The fuel pellet manufacturing method and manufacturing system of the present invention can be applied to all biomass material W1. Regarding the plastic waste W2, all plastic waste W2 can be used, but it is preferable that the plastic does not generate harmful substances when burned.

[0124] Furthermore, in the fuel pellet production system 10 of the first embodiment of the present invention, a mixture W3 obtained by mixing livestock manure W1A of the biomass raw material W1 with wrap film W2A for roll bales of plastic waste W2 is semi-carbonized in the semi-carbonized product production device 16. However, it is also possible to semi-carbonize the biomass raw material W1 and the plastic waste W2 separately in the semi-carbonized product production device 16 and then mix them to produce a mixture.

[0125] [Second embodiment of fuel pellet manufacturing system] The second embodiment of the fuel pellet manufacturing system 10 is a case in which fuel pellets W12 are manufactured by pelletizing an unsemi-carbonized plastic mixture W10, which is a mixture of semi-carbonized biomass material W1 and unsemi-carbonized plastic waste W2.

[0126] In the second embodiment, livestock manure W1A is used as the biomass material W1, and wrap film W2A for roll bales used for transporting and storing livestock feed is used as the plastic waste W2. As described above, unsemi-carbonized plastic refers to the original plastic that has not been treated in any way.

[0127] Furthermore, the crushing device 12, mixing device 14, semi-carbide manufacturing device 16, pulverizing device 18, and single-screw extrusion type pellet molding device 20 used in the first embodiment of the fuel pellet manufacturing system 10 can be used in the second embodiment of the fuel pellet manufacturing system 10, with the only difference being the order of processing, so explanations of the device structure, etc. will be omitted.

[0128] FIG. 8 is a schematic diagram of an apparatus flow showing the overall configuration of a fuel pellet manufacturing system 10 according to a second embodiment of the present invention, and FIG. 9 is an explanatory diagram for explaining a process flow showing the order of processing.

[0129] As shown in the equipment flow of Figure 8 and the process flow of Figure 9, the fuel pellet manufacturing system 10 of the second embodiment of the present invention is mainly composed of a semi-carbonized production process (S1A) of livestock manure W1A using a semi-carbonized production device 16 in step 1A, a crushing process (S2A) of wrap film W2A for roll bales using a crushing device 12 in step 2A, a mixing process (S3A) using a mixer 14 in step 3A, a crushing process (S4A) using a crusher 18 in step 4A, and a pellet molding process (S5A) using a pellet molding device 20 in step 5A.

[0130] In step 1A, the livestock manure W1A does not need to be crushed, so the semi-carbonized material production process is carried out without crushing using the semi-carbonized material production apparatus 16. This produces semi-carbonized material W8 through pyrolysis of the livestock manure W1A. In this case, since only the livestock manure W1A is pyrolyzed, the heating temperature in the semi-carbonized material production apparatus 16 should be set to 200 to 300°C.

[0131] Next, in the shredding step of step S2A, the wrap film W2A for roll bales is shredded into fragments by a shredding device 12 to produce shredded material W10. In this case, if the wrap film W2A for roll bales is originally in fragments, this step can be omitted.

[0132] Next, in the shredding process of step S3A, semi-carbonized livestock manure W1A W8 is first placed in the mixing tank 38 of the mixer 14, and then, while stirring with the agitator 40, crushed pieces W10 of the roll bale wrap film W2A are gradually mixed in. This produces an unsemi-carbonized plastic mixture W10, in which the semi-carbonized livestock manure W1A W9 and the crushed pieces W10 of the roll bale wrap film W2A are mixed evenly and uniformly. In this case, in the second embodiment, the roll bale wrap film W2A is not semi-carbonized, so the semi-carbonized livestock manure W1A and the unsemi-carbonized roll bale wrap film W2A have different materials and physical properties. This may make it difficult to mix the semi-carbonized livestock manure W1A and the unsemi-carbonized roll bale wrap film W2A evenly and uniformly in the mixer 14. Therefore, it is preferable that the crushing device 18 crush the wrap film W2A for roll bales into smaller pieces than in the first embodiment.

[0133] Next, in the pulverization step of step S4A, the unsemi-carbonized plastic mixture W10 is pulverized into powder by the pulverizer 18 to produce pulverized material for pellets W11.

[0134] Next, in the pellet forming process of step S5A, the pellet pulverized material W11 is formed into pellets by a single-screw extruder-type pellet forming device 20. The rod-shaped pellets extruded from a die 100 of the pellet forming device 20 are cut into pellet size by a cutter 102. This produces pellet-shaped fuel pellets W12 in which the livestock manure W1 is mixed with unsemi-carbonized wrap film for roll bales W2A.

[0135] In the case of the fuel pellet manufacturing system 10 of the second embodiment, there is a risk that pelletization will not be successful in the pellet molding device 20 due to differences in material and physical properties between the semi-carbonized livestock manure W1A and the unsemi-carbonized wrap film for roll bales W2A. For this reason, it is preferable to use a single-screw or twin-screw extruder type pellet molding device 20. The single-screw or twin-screw extruder type pellet molding device 20 can compress and knead while heating, making pelletization easier than other pellet molding devices. The manufactured fuel pellets W12 drop into the storage container 21 and are stored therein.

[0136] In this way, in the case of the fuel pellet manufacturing system of the second embodiment, by taking into consideration the differences in material and physical properties between semi-carbonized livestock manure W1A and unsemi-carbonized wrap film for roll bales W2A, it is possible not only to produce combustion pellets W12 with a high calorific value from biomass raw material W1, but also to contribute to the effective use of plastic waste W2 and cost reduction. Unless otherwise specified, the pellets of the present invention also include briquettes, which are larger in size.

[0137] (Third embodiment of the present invention) Next, a third embodiment of the fuel pellet manufacturing method will be described. The third embodiment of the fuel pellet manufacturing method is a fuel pellet manufacturing method for manufacturing fuel pellets from biomass raw materials, and includes a mixing step of mixing a first component derived from the biomass raw materials and a second component derived from plastic-containing waste to obtain a mixture, and a granulation step of molding the mixture into pellets to manufacture fuel pellets, wherein the plastic-containing waste contains a water-absorbent resin, and further includes a semi-carbonization step of pyrolyzing the first component and / or the mixture in an anaerobic environment to semi-carbonize them.

[0138] In the following, the differences from the first and second embodiments will be mainly described, and for matters not described below, such as the granulation process, the same methods as in the first and second embodiments can be adopted.

[0139] The most significant difference from the above-described embodiment is that a second component derived from plastic-containing waste is used to generate the mixture. This plastic-containing waste contains a water-absorbent resin. Examples of water-absorbent resins include polyacrylic acid copolymers such as sodium polyacrylate and potassium polyacrylate, as well as starch-based and cellulose-based water-absorbent polymers. Such water-absorbent resins are typically contained in packaging made of absorbent and / or water-permeable resin sheets, along with other water-absorbent materials (e.g., paper, pulp, wood, etc.) as needed, and are used as water-absorbent resin containers in products such as disposable diapers, sanitary products, pet sheets, portable emergency toilets, and agricultural and horticultural water-retaining materials.

[0140] Such water-absorbent resin containers contain multiple materials in a composite form, making it difficult to separate the materials and making recycling extremely difficult. Furthermore, many water-absorbent resins are characterized by their ability to retain moisture for long periods of time. Conversely, they are not well-suited to biodegradation, which also makes recycling difficult. Furthermore, depending on the application, water-absorbent resin containers may be contaminated with organic contaminants, such as feces, urine, blood, and bodily fluids, derived from living organisms such as humans and livestock. Considering hygiene, incineration has been the only option for disposal. The present inventors have noticed that such organic contaminants derived from living organisms also have the properties of a high-calorie fuel, and came up with the idea of ​​applying this to torrefied pellets, thereby completing the present invention.

[0141] One of the features of the fuel pellet manufacturing method of this embodiment is that it uses plastic-containing waste containing a water-absorbent resin container, such as disposable diapers, which includes a water-absorbent resin and a resin sheet that contains the water-absorbent resin, as the second component for generating the mixture. Another feature is that the mixture is mixed with a first component derived from a biomass material and a second component, and the mixture is torrefied in an anaerobic environment. According to the fuel pellet manufacturing method of this embodiment, which has these features, plastic-containing waste containing a water-absorbent resin container, which has previously been difficult to recycle, can be efficiently recycled into new fuel pellets. Furthermore, as described below, since the mixture is torrefied by heating at a predetermined temperature, the resulting fuel pellets do not pose any sanitation problems.

[0142] The semi-carbonization method is not particularly limited, and the semi-carbonization method and apparatus of the first embodiment can be used. Generally, water-absorbent resin waste often contains moisture. For example, disposable diapers often contain moisture derived from human urine and feces, while pet sheets often contain components derived from pet urine and feces. Therefore, it is preferable to include a drying step to remove this moisture before or in conjunction with the semi-carbonization step. The drying step is not particularly limited, but may be a step of heating the plastic-containing waste and / or mixture. The heating temperature is not particularly limited, but is preferably 100 to 200°C. The heating time can be selected appropriately depending on the amount of plastic-containing waste and / or mixture, and the end timing of the drying step can also be determined by monitoring the temperature of the plastic-containing waste and / or mixture due to heating.

[0143] In the drying step, the plastic-containing waste and / or the mixture is preferably heated in an anaerobic environment, which can suppress the incineration of organic matter.

[0144] In particular, the drying step is preferably carried out as part of the semi-carbonization step. Semi-carbonization can be carried out, in one form, by heating the mixture at a temperature of 250 to 350°C. However, when the drying step is carried out as part of the semi-carbonization step, the semi-carbonization step is preferably a two-stage heating step of the mixture. That is, the semi-carbonization step preferably includes a first stage in which the mixture is heated at a temperature of 100 to 200°C, and a second stage in which the mixture is heated at a temperature of 250 to 350°C after the first stage. Such a two-stage semi-carbonization step can be realized by using the semi-carbonized material manufacturing apparatus exemplified in the first embodiment.

[0145] In the torrefaction process, which includes a drying process, outgases are generated in the first stage, such as water vapor and volatile organic compounds, and in the second stage, such as carbon dioxide, carbon monoxide, hydrogen, and hydrocarbon gases. In the torrefaction process, it is preferable to heat the mixture in an anaerobic environment while discharging these outgases outside the system. This heating method can be implemented using the torrefaction apparatus according to the first embodiment. The conveyor tube 42 (a sealable container) of the torrefaction apparatus 16 is provided with a dry distillation gas exhaust pipe 58, which can be used to discharge the outgases outside the system (outside the conveyor tube 42). Furthermore, the dry distillation gas exhaust pipe 58 is provided with a check valve 60. When the open / close lid 56A of the hopper 56 is closed, the interior of the conveyor tube 42 becomes an anaerobic environment that prevents air from entering. This allows the mixture to be heated in an anaerobic environment while discharging the outgases outside the system. That is, the dry distillation gas exhaust pipe 58, equipped with the check valve 60, functions as a check valve-equipped discharge path.

[0146] Furthermore, the torrefaction process is preferably a process of heating the sealed container from outside the container, which can also be realized by the torrefaction production apparatus 16. That is, the conveyor tube 42 is directly heated by the combustion furnace 48, and the high-temperature exhaust gas generated by the combustion furnace 48 is sent into the flue 46A, so that the inside of the conveyor tube 42 can be heated from the outside.

[0147] The biomass raw materials and plastic-containing waste used in this embodiment preferably contain organic contaminants of biological origin. Examples of organic contaminants of biological origin include feces, urine, blood, and body fluids. In particular, the biomass raw materials preferably contain feces and urine of livestock and / or pets, and more preferably livestock and / or feces. Furthermore, the plastic-containing waste preferably contains human feces and / or urine, and more preferably human feces. In other words, the biomass raw materials and plastic-containing waste preferably contain feces of biological origin. Although feces is difficult to process due to its high load, it has the advantage of being able to be processed into highly efficient fuel by semi-carbonization.

[0148] Furthermore, the container used in the torrefaction process (specifically, the conveyor tube 42) preferably includes a discharge means for removing the torrefied mixture obtained through the torrefaction process and a heating means for heating the mixture from outside the container, the discharge means including a return means for transferring the torrefied mixture to the heating means, and the heating means preferably uses the torrefied mixture transferred by the return means as part or all of the fuel to heat the container. This configuration allows torrefaction to be carried out more efficiently, and also improves overall efficiency by recovering part of the torrefied mixture as energy without going through the granulation process.

[0149] The above steps can be realized by the devices specifically shown in the first embodiment. A specific example of the discharge means is a semi-carbonized material discharge line 50. A specific example of the return means is a screw conveyor 50C. The semi-carbonized mixture discharged from the conveyor tube 42 by the semi-carbonized material discharge line 50 is supplied by the screw conveyor 50C to a combustion furnace 48, which is a heating means, and is used as heating fuel for semi-carbonization.

[0150] The mixing process is carried out by a mixing device equipped with a mixing tank and an agitator for agitating the contents of the mixing tank, and the mixing tank is preferably formed to a volume size corresponding to the processing volume of one batch of the container. The torrefaction process using a container (specifically, conveyor tube 42) is, in a sense, a batch processing process. By matching the processing volume of one mixing tank, i.e., the container size, to the processing volume of one batch of the container, fuel pellets can be produced more efficiently and without waste. Note that, as a specific example of the mixing device, the mixing device 14 in the first embodiment can be used. [Explanation of symbols]

[0151] 10...Fuel pellet manufacturing system, 12...Crushing device, 14...Mixing device, 16...Semi-carbide manufacturing device, 18...Crushing device, 20...Pellet molding device, 21...Storage container, 22...Rotating blade, 24...Fixed blade, 26...Casing, 26A...Large diameter cylindrical portion, 26B...Small diameter cylindrical portion, 26C...Connecting cylindrical portion, 28...Rotating shaft, 30...Motor, 32...Bearing, 34...Hopper, 36...Discharge pipe, 38...Mixing tank, 40...Agitator, 40A...Agitating rod, 40B...Motor, 40C...Agitating blade, 42...Conveyor cylinder, 42A...Feed port, 44...Screw feeder, 44A...Rotating shaft, 46...Fume duct cover, 46A...Fume duct, 48...Combustion furnace, 48A...Combustion can, 48C...Top opening, 50...Semi-carbide discharge line, 50A...Discharge hopper, 50B...Storage tank, 50C...Screw conveyor, 50D...Connector, 52...Support frame, 54...Base frame, 56...Hopper, 56A...Opening and closing cover, 58...Dry distillation gas exhaust pipe, 60...Check valve, 62A...Bearing, 64 ...Stepless motor, 66...Chimney, 68...Car, 68A...Mounting base, 68B...Rotating shaft, 68C...Wheel, 68D...Coupling device, 70...Automobile, 72...Conveyor, 74...Control panel, 76...Casing, 78...Rotating blade, 80...Rotor, 82...Fixed blade, 84...Hopper, 86Powder discharge pipe, 88...Rotating shaft, 90...Cylindrical rotating part, 92...Bearing, 94...Motor, 96...Cylinder, 98...Screw, 100...Die, 100A...Discharge hole, 102...Cutting machine, 104 ...Rotation drive unit, 106...Hopper, 108...Coal bale, W1...Biomass raw material, W1A...Livestock manure, W2...Plastic waste, W2A...Wrap film for roll bale, W3...Crushed material, W4...Mixture, W5...Composite semi-carbonized material, W6...Ground material for pellets, W7...Fuel pellets, W8...Semi-carbonized material, W9...Crushed material, W10...Unsemi-carbonized plastic mixture, W11...Ground material for pellets, W12...Fuel pellets, X...Supply unit, Y...Compression unit, Z...Weighing unit

Claims

1. A method for producing fuel pellets from biomass raw materials, comprising: a mixing step of mixing a first component derived from the biomass raw material and a second component derived from the plastic-containing waste to obtain a mixture; a pelletizing step of pelletizing the mixture to produce fuel pellets, The plastic-containing waste contains a water-absorbing resin, The method for producing fuel pellets further includes a torrefaction step of pyrolyzing the mixture in an anaerobic environment to torrefy it.

2. 2. The method for producing fuel pellets according to claim 1, further comprising a drying step of removing at least a portion of the moisture contained in the water-absorbing resin by heating.

3. 3. The method for producing fuel pellets according to claim 2, wherein the plastic-containing waste includes a water-absorbent resin container comprising the water-absorbent resin and a resin sheet that accommodates the water-absorbent resin.

4. The torrefaction step is a step of heating the mixture in two stages while discharging outgassing from the system, The two-stage heating comprises a first stage in which the mixture is heated at a temperature of 100 to 200°C; 4. The method for producing fuel pellets according to claim 3, further comprising a second step of heating the mixture at a temperature of 250 to 350°C after the first step.

5. 5. The method for producing fuel pellets according to claim 4, wherein the torrefaction process is a process of placing the mixture in a container having an exhaust path with a check valve for exhausting the outgas, and heating the container from outside while the container is sealed.

6. The method for producing fuel pellets according to claim 5 , wherein the biomass raw material and the plastic-containing waste contain organic contaminants of biological origin.

7. The method for producing fuel pellets according to claim 6 , wherein the organic contaminants include feces of living organisms.

8. The container is provided with a carrying means for removing the torrefied mixture obtained through the torrefaction step, and a heating means for heating the mixture from outside the container, The conveying means includes a returning means for transferring the torrefied mixture to the heating means, The method for producing fuel pellets according to claim 7 , wherein the heating means is configured to heat the container using the torrefied mixture transferred by the returning means as part or all of the fuel.

9. the mixing step is carried out by a mixing device including a mixing tank and a stirrer that stirs the contents of the mixing tank; The method for producing fuel pellets according to claim 8 , wherein the mixing vessel is formed to have a volume size corresponding to the processing amount of one batch of the container.

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