Biomass solid fuel production device and biomass solid fuel production method

Abstract

To provide a biomass solid fuel production device capable of suppressing collapse of biomass molded bodies during production. [Solution] The biomass solid fuel production apparatus (100) includes a rotary kiln (2) that carbonizes biomass molded bodies formed from raw biomass. The rotary kiln (2) includes a kiln body (20), a raw material supply unit (30) that supplies the biomass molded bodies to the upstream end of the kiln body (20), and an inert gas supply unit (50) that supplies an inert gas to the upstream end of the interior of the kiln body (20).

Description

[Technical Field]

[0001] The present disclosure relates to a biomass solid fuel production apparatus. [Background technology]

[0002] Patent Document 1 discloses a configuration in which, in a waste pyrolysis gasification system, purging is performed by introducing an inert gas into a dust feeder that supplies waste to a rotary kiln furnace. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-098015 Summary of the Invention [Problem to be solved by the invention]

[0004] When producing biomass solid fuel by heating molded biomass bodies using the device described in Patent Document 1, the molded biomass bodies may break down due to steam and other factors generated from the biomass, and may adhere to the inside of the furnace.

[0005] The present disclosure has been made in view of the above, and aims to provide a biomass solid fuel production device that can suppress collapse of biomass molded bodies during production. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a biomass solid fuel production apparatus according to one embodiment of the present disclosure is a biomass solid fuel production apparatus including a rotary kiln that carbonizes biomass molded bodies formed from raw biomass, wherein the rotary kiln comprises a kiln body, a raw material supply unit that supplies the biomass molded bodies to the upstream end of the kiln body, and an inert gas supply unit that supplies an inert gas to the upstream end of the interior of the kiln body.

[0007] According to the biomass solid fuel production apparatus, an inert gas is supplied to the upstream end of the kiln body into which the pre-heated biomass molded bodies with a high moisture content are fed, thereby preventing the collapse of the biomass molded bodies due to condensation of water vapor generated from the biomass molded bodies near the upstream end.

[0008] The inert gas supply unit may be configured to discharge the inert gas in a radial direction inside the kiln body.

[0009] This configuration allows the inert gas to be supplied to the corners of the upstream end of the kiln body, where steam generated from the molded biomass bodies tends to accumulate, further suppressing collapse of the molded biomass bodies due to condensation of steam.

[0010] The rotary kiln may be an externally heated kiln, and the upstream end of the kiln body may be a non-heated zone having no heating section on the outer periphery.

[0011] As described above, when the upstream end is an unheated zone, water vapor is more likely to condense in this area. By supplying an inert gas to the upstream end, condensation due to retention of water vapor can be appropriately suppressed.

[0012] The inert gas supply unit may also discharge the inert gas into the raw material supply unit.

[0013] The above configuration also prevents condensation of water vapor that enters the raw material supply section connected to the rotary kiln, thereby suppressing the collapse of biomass molded bodies inside the supply section. [Effects of the Invention]

[0014] According to the present disclosure, a biomass solid fuel production device is provided that can suppress collapse of biomass molded bodies during production. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a flow diagram illustrating an outline of a method for producing a biomass solid fuel according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic configuration diagram of a biomass solid fuel production apparatus according to one embodiment of the present disclosure. [Figure 3] FIG. 3 is an enlarged view of a portion of the upstream side of the rotary kiln. [Figure 4] FIG. 4 is a schematic diagram of the upstream side of the rotary kiln as viewed from the axial direction. [Figure 5] FIG. 5 is an enlarged view of the tip of the first nozzle. [Figure 6] 6(a) and 6(b) are diagrams showing modified examples of the first nozzle. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicated explanations will be omitted.

[0017] Fig. 1 is a flow diagram illustrating an outline of a method for producing a biomass solid fuel according to one embodiment of the present disclosure. As shown in Fig. 1, biomass, which is the raw material for the biomass solid fuel, is converted into pellet-shaped biomass molded bodies (white pellets: hereinafter referred to as "WP") through a crushing step (S01) and a molding step (S02). The WP is heated in a heating step (S03) to be carbonized, and becomes a biomass solid fuel (pelletizing before torefaction: hereinafter referred to as "PBT"). The PBT is then converted into a finished product through a classification and cooling step (S04) as needed.

[0018] The crushing step (S01) is a step of crushing and crushing the raw biomass (raw biomass). The type of raw biomass is not particularly limited and can be selected from woody and herbaceous species. The tree species and parts of the raw biomass are not particularly limited. For example, in one embodiment, the raw biomass contains at least one species selected from the group consisting of rubber tree, acacia, dipterocarpaceae tree species, radiata pine, and a mixture of larch, spruce, and birch. Larch, spruce, and birch may each be used alone as the raw biomass, but a mixture of two or more, preferably three, of these species can also be used. The raw biomass can also contain at least one species (or a mixture of two or three) selected from the group consisting of a mixture of spruce, pine, and fir.

[0019] The raw material may further contain other tree species other than those mentioned above. In one embodiment of the present invention, the content of one or more species selected from the group consisting of rubber tree, acacia, tree species of the Dipterocarpaceae family, radiata pine, and a mixture of larch, spruce, and birch relative to the total weight of the raw material biomass is preferably 50% by weight or more, more preferably 80% by weight or more, and may even be 100% by weight.

[0020] In addition, as raw materials, Douglas fir, American larch, cedar, cypress, European sylvestris, old almond trees, almond shells, walnut shells, sago palm, EFB (empty fruit bunches left over from palm oil processing), meranti, acacia wood, acacia bark, eucalyptus, teak, spruce and birch, rubber, etc. may also be used.

[0021] The particle size of the biomass after pulverization is not particularly limited, but can be about 100 μm to 3000 μm on average, preferably 400 μm to 1000 μm on average. Note that the particle size of the biomass powder can be measured using a known measurement method.

[0022] The molding step (S02) is a step in which the crushed biomass is molded into a block using a known molding technique. The molded biomass block (WP) can be made into pellets or briquettes. The size of the WP can be changed as needed. In the molding step, no binding agent such as a binder is added, and the crushed biomass is molded by compressing and pressurizing it.

[0023] The heating step (S03) is a step in which the biomass molded bodies (WP) are heated at 150°C to 400°C (low-temperature carbonization) to produce a biomass solid fuel (PBT) that has strength and water resistance while maintaining the shape of the molded bodies. The heating step is performed using the biomass solid fuel production apparatus 100 described below.

[0024] The heating temperature (heating temperature of PBT in the kiln body 20: also called carbonization temperature) is determined appropriately depending on the shape and size of the raw biomass and aggregates, but is set to less than 300°C. It is more preferably 200°C or higher and lower than 300°C. It is even more preferably 230°C or higher and lower than 300°C. Furthermore, a temperature between 230°C and 280°C is preferable. The heating time in the heating step is not particularly limited, but can be 0.2 to 3 hours.

[0025] The classification and cooling step (S04) is a step in which the PBT obtained in the heating step is classified and cooled to be commercialized. Classification and cooling may be omitted, or only one of the steps may be performed. If necessary, the classified and cooled PBT can be used as a solid fuel product.

[0026] The biomass solid fuel obtained after the heating step (S03) preferably has a COD (chemical oxygen demand) of 3000 ppm or less when soaked in water. Here, the COD (chemical oxygen demand) of the soaking water when the biomass solid fuel is soaked in water (also simply referred to as "COD") refers to the COD value obtained by preparing a soaking water sample for COD measurement in accordance with the Environment Agency Notification No. 13 (A) of 1973 (Method for testing metals, etc. contained in industrial waste) and analyzing it according to JIS K0102(2016)-17.

[0027] The biomass solid fuel obtained after the heating step preferably has a crushability index (HGI) based on JIS M 8801 of 15 to 60, more preferably 20 to 60. The biomass solid fuel also preferably has a BET specific surface area of ​​0.15 m 2 / g~0.8m 2 / g, and 0.15m 2 / g~0.7m 2 / g Furthermore, the biomass solid fuel preferably has an equilibrium moisture content after immersion in water of 15 wt% to 65 wt%, more preferably 15 wt% to 60 wt%.

[0028] The biomass solid fuel obtained after the heating step has a fuel ratio (fixed carbon / volatile matter) of 0.2 to 0.8, a higher heating value on an anhydrous basis of 4,800 kcal / kg to 7,000 kcal / kg, a molar ratio of oxygen (O) to carbon (C) of O / C of 0.1 to 0.7, and a molar ratio of hydrogen (H) to carbon (C) of H / C of 0.8 to 1.3. When the physical property values ​​of the biomass solid fuel after the heating step are within these ranges, the COD in wastewater during storage can be reduced, while pulverization can be reduced, improving handleability during storage. The physical property values ​​of the biomass solid fuel can be adjusted to the above ranges by, for example, adjusting the species and part of the biomass used as the raw material, the heating temperature during the heating step, etc. The proximate analysis values, elemental analysis values, and higher heating values ​​in this specification are based on JIS M 8812, 8813, and 8814.

[0029] Furthermore, the maximum temperature reached in the self-heating test for the biomass solid fuel obtained after the heating process is less than 200°C. The self-heating test is a test specified in the "United Nations: Recommendations on the Transport of Dangerous Goods: Manual of Test Methods and Criteria: 5th Edition: Self-heating Test."

[0030] Here, the biomass solid fuel production apparatus 100 used in the heating step (S03) will be described with reference to Figures 2 to 5. Figure 2 is a schematic diagram illustrating the configuration of the biomass solid fuel production apparatus used in the heating step. Also, Figure 3 is an enlarged view of the upstream side of the rotary kiln, and Figure 4 is a view of the kiln body and raw material supply section as seen from the upstream side. Furthermore, Figure 5 is a view illustrating the shape of the tip of the first nozzle attached to the kiln body.

[0031] 2, the biomass solid fuel production apparatus 100 has a hopper 1 and a rotary kiln (heating furnace) 2. The hopper 1 and the rotary kiln 2 are controlled by a control unit (not shown).

[0032] Hopper 1 has the function of storing biomass molded bodies (WP). The WP stored in hopper 1 is sequentially supplied to rotary kiln 2, where it is heated. By heating the WP, biomass solid fuel (PBT) is produced. The PBT produced by rotary kiln 2 is transported by conveyor 3.

[0033] The rotary kiln 2 is a so-called externally heated type. The rotary kiln 2 has a kiln body 20 into which the WP to be heated is introduced and heated (low-temperature carbonization), a raw material supply unit 30 connected to the upstream end of the kiln body 20, a heating unit 40 that heats the kiln body 20, and an inert gas supply unit 50 that supplies inert gas into the kiln body 20.

[0034] The kiln body 20 has a substantially cylindrical shape, and biomass molded bodies (WP), which are the material to be heated, are introduced into the interior from one end, and the biomass solid fuel (PBT) after heating (low-temperature carbonization) is discharged from the other end. The kiln body 20 has a cylindrical tube 21 and a seal plate 22 provided at the upstream end of the tube 21. The tube 21 is a cylindrical member extending from the upstream side (hopper 1 side) to the downstream side (conveyor 3 side). The tube 21 is supported by an upstream roller 25 and a downstream roller 26 so as to be rotatable about a central axis X of the tube 21 (see Figures 3 and 4), which extends in the direction of movement of the WP. The central axis X of the tube 21 serves as the rotation axis of the kiln body 20.

[0035] The sealing plate 22 is a disk-shaped plate connected to the upstream end of the cylindrical body 21. A circular opening 22a is provided in the center of the sealing plate 22. The raw material supply unit 30 is connected to the upstream side of the opening 22a. The sealing plate 22 also has an opening 22b for a nozzle included in the inert gas supply unit 50, at a position different from the opening 22a.

[0036] The raw material supply unit 30 has a function of supplying the material to be heated (WP) stored in the hopper 1 to the kiln body 20. The raw material supply unit 30 has a cylindrical supply pipe 31. Inside the supply pipe 31, for example, a screw feeder (not shown) for moving the material to be heated (WP) toward the kiln body 20 may be provided.

[0037] The heating section 40 has a hot gas passage 41 on the outer periphery of the cylindrical body 21 of the kiln body 20, and a gas inlet 42 and a gas outlet 43 provided in the hot gas passage 41. The hot gas passage 41 is formed along the outer periphery of the cylindrical body 21. The gas inlet 42 is provided, for example, downstream of the hot gas passage 41 along the kiln body 20. The gas outlet 43 is provided, for example, upstream of the hot gas passage 41 along the kiln body 20. The heating section 40 supplies hot gas from the external heat source 4 through the gas inlet 42, passes through the hot gas passage 41, and discharges it from the gas outlet 43. In the rotary kiln 2 shown in this embodiment, the hot gas passage 41 is provided around the kiln body 20, so the interior of the kiln body 20 is indirectly heated.

[0038] The temperature of the kiln body 20 of the rotary kiln 2 can be controlled by controlling the external heat source 4 with a control unit (not shown) and appropriately changing the temperature at the gas inlet 42 of the hot gas path 41. Note that the rotary kiln 2 shown in Figures 2 and 3 is of a countercurrent type in which the direction of movement of the biomass molded bodies (WP) (direction from the hopper 1 side to the conveyor 3 side) is opposite to the direction of movement of the hot gas, but it may also be of a parallel current type. Note that the oxygen concentration inside the rotary kiln 2 is set to, for example, 10% or less.

[0039] The hot gas passage 41, which is arranged on the outer periphery of the cylindrical body 21 of the kiln main body 20, is located in a position that does not overlap with the rollers 25, 26, i.e., between the rollers 25, 26. Therefore, the areas upstream of the hot gas passage 41 (the area interfering with the roller 25) and downstream of the hot gas passage 41 (the area interfering with the roller 26) are areas that are difficult to heat with hot gas. These areas become so-called non-heated zones. In this way, in the kiln main body 20, the area that is surrounded by the hot gas passage 41 becomes the heated zone, and the other areas become the non-heated zone.

[0040] The kiln body 20 is installed at an angle so that the upstream side (hopper 1 side) is at the top and the downstream side (conveyor 3 side) is at the bottom. The installation angle of the kiln body 20 can be changed as appropriate depending on the size of the kiln body 20, the movement speed of the WP inside the kiln body 20, etc.

[0041] The inert gas supply unit 50 introduces an inert gas into the kiln body 20 and the raw material supply unit 30. Examples of the inert gas include N2 and CO2. Alternatively, air with an oxygen concentration of 10% or less may be used.

[0042] The inert gas supply unit 50 includes a first nozzle 51 that introduces gas into the interior of the kiln body 20, a gas supply source 52 that supplies inert gas to the first nozzle 51, piping 53 that connects the first nozzle 51 and the gas supply source 52, a second nozzle 54, and a gas supply source and piping (not shown) that supply inert gas to the second nozzle 54. The inert gas may be supplied to the second nozzle 54 from the same gas supply source 52 as the first nozzle 51, or from a gas supply source different from the gas supply source 52. In addition, part of the piping to the first nozzle 51 and the second nozzle 54 may be shared.

[0043] The first nozzle 51 may be, for example, cylindrical and attached so as to penetrate the seal plate 22 below the supply pipe 31 of the raw material supply unit 30. Also, as shown in FIG. 5, an opening 51a may be provided on the side near the tip of the first nozzle 51 (the end opposite the inert gas supply unit 50 and located inside the kiln body 20). Furthermore, the end face 51b of the tip of the first nozzle 51 may have a closed shape. Also, as shown in FIG. 4, the first nozzle 51 is fixed to the seal plate 22 so that the opening 51a inserted into the kiln body 20 faces upward.

[0044] The second nozzle 54 may be, for example, cylindrical and inserted into the supply pipe 31 from above. The second nozzle 54 may be disposed at a location away from the downstream end 31a of the supply pipe 31 (the connection portion with the seal plate 22) such that a backflow of gas does not occur. The tip of the second nozzle 54 (the end portion disposed inside the supply pipe 31) may be open.

[0045] When inert gas is introduced from the first nozzle 51, the inert gas moves in a direction (radial direction) intersecting the central axis X. Specifically, because the opening 51a of the first nozzle 51 faces upward, the inert gas is discharged from the first nozzle 51 toward the upper part of the kiln body 20. The inert gas discharged from the first nozzle 51 is supplied near the upstream end of the kiln body 20 (near region A shown in FIG. 3 ), and promotes the movement of gas remaining near region A.

[0046] Furthermore, when the inert gas is introduced from the second nozzle 54, the inert gas moves in a direction (radial direction) intersecting the central axis of the supply pipe 31. Specifically, the inert gas is discharged from the second nozzle 54 toward the downward direction of the supply pipe 31.

[0047] The inert gas supply unit 50 may be configured to continuously introduce inert gas from the first nozzle 51 and the second nozzle 54 while the rotary kiln 2 is operating, or may be configured to repeatedly introduce inert gas at predetermined intervals. The timing of supplying inert gas from the first nozzle 51 and the second nozzle 54 may be simultaneous, or there may be a timing when only one of them is supplied. In this way, the timing of supplying inert gas can be changed as appropriate. The amount of gas supplied from each of the first nozzle 51 and the second nozzle 54 can also be changed as appropriate. For example, the amount of gas supplied can be adjusted to a level that prevents the biomass molded bodies (WP) inside from scattering when inert gas is supplied from the first nozzle 51 and the second nozzle 54.

[0048] In the biomass solid fuel production apparatus 100, a gas flow is formed inside the kiln body 20 in the same direction as the movement of the biomass molded bodies (WP), i.e., a parallel flow from the upstream side to the downstream side. This gas flow is formed by providing an outlet (not shown) for discharging gas moving inside the kiln body 20 downstream of the discharge of the PBT produced by the rotary kiln 2 onto the conveyor 3. Therefore, the inert gas supplied from the first nozzle 51 and the second nozzle 54 of the inert gas supply unit 50 moves downstream like the internal gas flow and is discharged from the outlet.

[0049] As described above, in the biomass solid fuel production apparatus 100 according to this embodiment, the inert gas supply unit 50 supplies inert gas to the upstream end of the kiln body 20 where the pre-heated biomass molded bodies with a high moisture content are fed, specifically near the region A. This prevents the biomass molded bodies from collapsing due to condensation of water vapor generated from the biomass molded bodies near the upstream end.

[0050] It has been known for some time that biomass solid fuel is produced by heating (low-temperature carbonization) biomass molded bodies in a rotary kiln 2. In a rotary kiln 2, the temperature tends to be lower on the upstream side than on the downstream side. If unheated biomass molded bodies are introduced into the kiln body 20 under such conditions, water vapor generated from the biomass molded bodies is likely to condense at the upstream end, and the water vapor may cause the biomass molded bodies to collapse.

[0051] In particular, if water vapor (moisture) adheres to the biomass molded bodies before carbonization, the biomass molded bodies may collapse and pulverize due to their low water resistance. In this case, the shape of the biomass solid fuel after carbonization is also collapsed, which may reduce the recovery rate of biomass solid fuel with the specified shape. Furthermore, the collapsed and pulverized biomass molded bodies may adhere to the inner surface and blades of the kiln body 20, which may reduce the functionality of the rotary kiln 2.

[0052] In contrast to this, as described above, by supplying an inert gas to the upstream end using the inert gas supply unit 50, it is possible to move (purge) the water vapor from the upstream end, thereby preventing the collapse of the biomass molded body due to condensation of moisture near the upstream end.

[0053] Here, the inert gas supply unit 50 may be configured to discharge the inert gas radially inside the kiln body 20. Furthermore, the configuration for discharging the inert gas radially may include a first nozzle 51. With this configuration, compared to supplying the inert gas in a direction along the central axis X inside the kiln body 20, the inert gas can be supplied to corners at the upstream end inside the kiln body 20 where water vapor generated from the biomass molded bodies is likely to stagnate and condense. Therefore, collapse of the biomass molded bodies can be more effectively suppressed. Furthermore, by using the first nozzle 51 to discharge the inert gas radially, it becomes possible to precisely control the discharge direction.

[0054] In the kiln body 20, water vapor tends to accumulate and condense at the upstream end, particularly at the upper corners. Therefore, as described in the above embodiment, by configuring the first nozzle 51 to discharge inert gas upward, water vapor can be effectively purged from the corners. However, if the first nozzle 51 is configured to discharge inert gas at least radially, the inert gas is discharged in a direction that interferes with the gas flow inside the kiln body 20 from the upstream side to the downstream side, promoting the radial movement of gas containing water vapor. Therefore, by discharging inert gas at least radially, the movement of water vapor accumulating in the upper corners is promoted, further suppressing the collapse of biomass molded bodies due to condensation of water vapor. Even if the inert gas is discharged into the kiln body 20 in the direction of the central axis X, it is possible to at least cause a change in the gas flow inside the kiln body 20, thereby promoting the movement of water vapor.

[0055] Furthermore, as described above, when the rotary kiln 2 is externally heated and the upstream end of the kiln body 20 is an unheated zone, water vapor is more likely to condense in this area. Conversely, supplying an inert gas to the upstream end can appropriately suppress condensation due to stagnation of water vapor. A structural feature of the externally heated rotary kiln 2 is that rollers 25 can be provided near the entrance as a mechanism for rotating the kiln. In this case, it is difficult to place a heating unit on the outer periphery around the rollers 25, and this area inevitably becomes an unheated zone, which creates the problem of water vapor being more likely to stagnate. Conversely, supplying an inert gas as described above can promote the movement of water vapor in the unheated zone.

[0056] The inert gas supply unit 50 may also supply inert gas into the raw material supply unit 30 using the second nozzle 54 or the like. When inert gas is supplied to the upstream end of the kiln body 20, some water vapor may migrate from the kiln body 20 into the upstream raw material supply unit 30. In response to this, by supplying inert gas into the raw material supply unit 30 as well as the kiln body 20 as described above, collapse of the biomass molded bodies inside the raw material supply unit 30 can also be suppressed.

[0057] In the rotary kiln 2, the carbonization temperature in the heating zone where the heating unit 40 is provided on the outer periphery of the kiln body 20 can be set to less than 300°C. When the carbonization temperature in the heating zone of the kiln body 20 of the rotary kiln 2 is less than 300°C, the temperature rise in the non-heating zone adjacent to the heating zone is suppressed. Therefore, condensation of water vapor generated during heating of biomass shaped bodies is relatively likely to occur. In a typical biomass solid fuel production process, heating is performed at a carbonization temperature of 500°C or higher, so the non-heating zone surrounding the heating zone also becomes relatively hot, creating an environment in which water vapor condensation is unlikely to occur. On the other hand, when the carbonization temperature is less than 300°C, as in the biomass solid fuel production apparatus 100 of this embodiment, the temperature rise in the non-heating zone adjacent to the heating zone is small (for example, less than 100°C). Therefore, water vapor condensation is more likely to occur, which in turn promotes the collapse and pulverization of biomass shaped bodies.

[0058] In contrast to this, by supplying an inert gas to the upstream end using the inert gas supply unit 50 as described above, the effect of suppressing the collapse and pulverization of the biomass molded bodies is more pronounced compared to conventional rotary kilns, making it possible to more effectively produce biomass solid fuel in which collapse during production is suppressed.

[0059] However, the configuration described in the above embodiment can be applied even if the carbonization temperature in the kiln body 20 is 300°C or higher. Furthermore, even when the carbonization temperature in the kiln body 20 is 300°C or higher, by applying the configuration described in the above embodiment, it is possible to obtain the effect of producing a biomass solid fuel that is suppressed from collapsing during production.

[0060] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments and can be modified in various ways.

[0061] For example, it is possible to appropriately change the configuration and arrangement of each part of the biomass solid fuel production apparatus 100, including the rotary kiln 2. For example, it is also possible to appropriately change the shape and arrangement of the inlet for the biomass molded bodies, the outlet for the biomass solid fuel, etc.

[0062] The arrangement, shape, and number of the first nozzle 51 and the second nozzle 54 may be modified as needed. For example, the shape of the first nozzle 51 capable of discharging the inert gas in a radial direction intersecting the central axis X may be modified as needed. For example, the nozzle itself may be bent and have an open end 51c, as in the first nozzle 51A shown in FIG. 6(a). Alternatively, the nozzle may have multiple openings 51a on its side, as in the first nozzle 51B shown in FIG. 6(b). Furthermore, because the discharge direction of the inert gas is not limited to the radial direction, the shape of the first nozzle may be modified as needed depending on the discharge direction. Furthermore, the attachment position of the first nozzle 51 relative to the seal plate 22 may also be modified. For example, the opening 22b for attaching the first nozzle 51 may be provided above the raw material supply unit 30. Furthermore, a configuration in which multiple first nozzles 51 and multiple second nozzles 54 are provided may be used. [Explanation of symbols]

[0063] 1...hopper, 2...rotary kiln, 3...conveyor, 4...external heat source, 20...kiln body, 21...cylindrical body, 22...sealing plate, 25, 26...rollers, 30...raw material supply section, 31...supply pipe, 40...heating section, 41...hot gas path, 50...inert gas supply section, 51, 51A, 51B...first nozzle, 52...gas supply source, 53...piping, 54...second nozzle, 100...biomass solid fuel production device.

Claims

1. A biomass solid fuel production apparatus including a rotary kiln that carbonizes biomass molded bodies obtained by molding raw biomass, The rotary kiln is The kiln body and A raw material supply unit that supplies the biomass molded body to the upstream end of the kiln body; An inert gas supply unit that supplies an inert gas to an upstream end of the interior of the kiln body; A biomass solid fuel production device comprising:

2. The biomass solid fuel production apparatus according to claim 1 , wherein the inert gas supply unit discharges the inert gas in a radial direction inside the kiln body.

3. The rotary kiln is an externally heated type, The biomass solid fuel production apparatus according to claim 1 or 2, wherein the upstream end of the kiln body is a non-heating zone that does not have a heating section provided on its outer periphery.

4. The biomass solid fuel production apparatus according to any one of claims 1 to 3, wherein the inert gas supply unit also supplies the inert gas into the raw material supply unit.

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