Carbonization furnace and gasification system

Abstract

To provide a carbonization furnace capable of efficiently burning a pyrolysis gas generated in a process of carbonization, and a gasification system using carbide produced in the carbonization furnace.SOLUTION: A carbonization furnace comprises: a cylindrical body part extending vertically and having an inner space; a heating part provided below the inner space; and a baffle provided on an inner wall of the body part, wherein the heating part is a cylindrical member with a closed upper end, and is arranged coaxially with the body part, the baffle is provided at a position of the same height as an apex of the heating part or higher than the apex, a distance from an end of the baffle on an inner wall side to an end of the body part on a center side is shorter than an inner radius of the body part, and an edge of the baffle on the center side is in contact with or overlaps with the heating part in a plane view.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a carbonization furnace and a gasification system. [Background technology]

[0002] In recent years, methods have been considered for treating organic matter and biomass discharged from households and industries and reusing them as charcoal. In the following explanation, "organic matter discharged from households and industries" may be referred to as "organic waste." For example, Patent Document 1 discloses a carbonization furnace that carbonizes organic waste. The carbonization furnace described in Patent Document 1 is said to be capable of efficiently carbonizing without lowering the atmospheric temperature. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-270050 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a carbonization furnace, organic matter such as biomass and organic waste is thermally decomposed in an oxygen-free or low-oxygen atmosphere to produce carbonized matter and pyrolysis gas resulting from the decomposition of the organic matter. In the carbonization furnace, the generated pyrolysis gas is combusted and the combustion heat is effectively utilized, thereby reducing the energy required for carbonization. However, if the pyrolysis gas is not sufficiently combusted, a problem occurs in that black smoke is generated.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a carbonization furnace capable of efficiently combusting pyrolysis gas generated during the carbonization process, and a further object to provide a gasification system utilizing the char produced in the carbonization furnace. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the present invention includes the following aspects.

[0007] [1] A carbonization furnace comprising: a cylindrical main body portion extending in the vertical direction and having an internal space; a heating portion provided below the internal space; and a baffle provided on the inner wall of the main body portion, wherein the heating portion is a cylindrical member with a closed upper end and is arranged coaxially with the main body portion, the baffle is provided at the same height as an apex of the heating portion or at a position higher than the apex, the distance from the inner wall side end of the baffle to the center side end of the main body portion is shorter than the inner radius of the main body portion, and the center side end of the baffle is in contact with or overlaps the heating portion in a planar view.

[0008] [2] The carbonization furnace described in [1], wherein the difference between the inner radius of the main body and the outer radius of the heating portion is 300 mm or less.

[0009] [3] A carbonization furnace as described in [1] or [2], wherein the height at which the baffle is installed on the inner wall can be changed.

[0010] [4] A carbonization furnace described in any one of [1] to [3], wherein the baffle is provided around the entire circumference of the inner wall.

[0011] [5] The carbonization furnace described in [4], wherein the baffle is annular in plan view.

[0012] [6] A carbonization furnace described in any one of [1] to [3], wherein the main body has an inlet in the side wall for introducing raw materials, the inlet being located above the baffle, the baffle having a cutout portion on part of the entire circumference of the inner wall, and the position of the cutout portion overlaps with the position of the inlet in the circumferential direction of the inner wall.

[0013] [7] A carbonization furnace described in any one of [1] to [6], comprising an ignition section, the ignition section being provided at a position higher than the apex of the heating section.

[0014] [8] A gasification system comprising the carbonization furnace described in any one of [1] to [7] and a reforming furnace for obtaining water gas and activated carbon from the carbonized material produced in the carbonization furnace and superheated steam. Effect of the Invention

[0015] According to the present invention, it is possible to provide a carbonization furnace capable of promoting the combustion of pyrolysis gas generated during the carbonization process. Furthermore, it is possible to provide a gasification system utilizing the char produced in the carbonization furnace. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a cross-sectional view showing a carbonization furnace 1. [Diagram 2] FIG. 2 is a plan view showing the baffle 30. [Diagram 3] FIG. 3 is a schematic diagram showing the flow of pyrolysis gas in the carbonization furnace 1. As shown in FIG. [Figure 4] FIG. 4 is a plan view showing the baffle. [Diagram 5] FIG. 5 is a cross-sectional view showing the baffle. [Figure 6] FIG. 6 is a block diagram illustrating a gasification system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, a carbonization furnace according to each embodiment will be described with reference to Figures 1 to 6. In addition, in all the following drawings, the dimensions and ratios of each component are appropriately changed in order to make the drawings easier to see.

[0018] In the following description, an xyz Cartesian coordinate system is set, and the positional relationship of each member is described with reference to this xyz Cartesian coordinate system. Here, a specific direction in a horizontal plane is defined as the x-axis direction, a direction perpendicular to the x-axis direction in the horizontal plane is defined as the y-axis direction, and a direction perpendicular to both the x-axis direction and the y-axis direction (i.e., the vertical direction) is defined as the z-axis direction.

[0019] <Carbonization furnace> Fig. 1 is a cross-sectional view of a carbonization furnace according to an embodiment. As shown in Fig. 1, the carbonization furnace 1 mainly includes a main body 10, a heating section 20 provided below the main body 10, and a baffle 30 provided on the inner wall of the main body 10. In this specification, the "carbonization furnace" refers to a carbonization furnace for treating biomass, organic waste, and the like.

[0020] In this specification, "biomass" refers to resources derived from living organisms, excluding fossil resources. Examples of biomass include thinned wood, pruned branches, lumber waste, bamboo, and rice straw.

[0021] In addition, the term "organic waste" refers to waste made from organic matter. Examples of organic waste include food waste, construction waste, shredder dust, livestock waste, sludge, and general waste generated from households.

[0022] In the following description, biomass and organic waste are referred to as “raw material.” In the carbonization furnace, biomass is preferably processed as the raw material.

[0023] It is preferable that the raw material is dried in advance and the moisture content is appropriately adjusted before being fed into the carbonization furnace 1. This is because it is possible to increase the carbonization efficiency and the carbonized product yield. The moisture content of the raw material fed into the carbonization furnace 1 is preferably 10% by mass or more and 20% by mass or less. More preferably, it is 15% by mass or more and 20% by mass or less.

[0024] The carbonization furnace 1 heat-treats the input raw materials and produces charcoal. In the process of producing charcoal from the raw materials, the carbonization furnace 1 performs "decomposition combustion" of the raw materials, "carbonization" of the solid matter produced by the decomposition combustion, and "combustion" of the pyrolysis gas produced by the decomposition combustion.

[0025] In this specification, the term "decomposition combustion" refers to a reaction in which the raw material is decomposed into solid matter including charcoal and pyrolysis gas.

[0026] In this specification, the term "carbide-containing solid content" refers to an intermediate product of a reaction that produces carbide from raw materials. The carbide-containing solid content includes not only the carbide that is the reaction target, but also intermediate products in which a part of the decomposition reaction has progressed from the raw materials but has not yet turned into carbide. Hereinafter, the term "carbide-containing solid content" may be abbreviated to simply "solid content."

[0027] In this specification, "carbonization" refers to a reaction that further advances the thermal decomposition of the solid matter generated by combustion decomposition, thereby increasing the content of char in the solid matter.

[0028] In this specification, "pyrolysis gas" refers to a mixed gas generated by pyrolysis of a raw material. The pyrolysis gas is a mixed gas containing, for example, carbon monoxide, hydrogen, hydrocarbons, sulfur oxides, nitrogen oxides, etc. The pyrolysis gas is combustible. In the carbonization furnace 1, the pyrolysis gas generated by "decomposition combustion" is "combusted" and consumed. The pyrolysis gas processed by combustion becomes "exhaust gas."

[0029] The raw material and the pyrolysis gas correspond to the "combustible material" according to the present invention.

[0030] Each component of the carbonization furnace 1 will be described below in order.

[0031] (1) Main body The shape of the main body 10 is cylindrical with an internal space 10a and extends in the vertical direction (z-axis direction). For example, the main body 10 may be a circle with a different radius depending on the height in a plan view. Alternatively, the main body 10 may have irregularities on the inner or outer surface of the side wall.

[0032] The size of the main body 10 may be set based on the estimated amount of raw material to be processed or the estimated amount of carbonized material to be produced, depending on the expected operating conditions of the carbonization furnace 1. For example, the outer diameter of the main body 10 is 2600 mm, and the inner diameter is 2000 mm. For example, the height of the main body 10 is 5000 mm.

[0033] The main body 10 has an inlet 11, an outlet 12, an ignition section 13, an air supply port 10b, an air supply port 10c, and an exhaust port 14.

[0034] (Inlet port 11) The inlet 11 is a component for feeding the raw material into the carbonization furnace 1. The inlet 11 is provided in a side wall of the main body 10. The inlet 11 is connected to a means (not shown) for feeding the raw material into the internal space 10a.

[0035] The means for feeding the raw material is not limited, and examples thereof include a screw feeder and a table feeder. The raw material is fed into the internal space 10a of the main body 10 through the feed port 11. The raw material may be fed from the feed port 11 continuously or intermittently. The amount of the raw material fed can be appropriately adjusted.

[0036] It is preferable that the temperature near the inlet 11 be 800° C. or higher in order to completely combust the pyrolysis gas. There is no upper limit to the temperature as long as it does not damage the carbonization furnace, but the temperature near the inlet 11 is generally 1200° C. or lower, more preferably 1150° C. or lower.

[0037] (Outlet 12) The outlet 12 is a component for recovering the carbonized material produced in the carbonization furnace 1. The outlet 12 is provided at the bottom of the main body 10.

[0038] (Ignition part 13) The ignition unit 13 is an ignition device for heating the heating unit 20 and further warming the internal space 10a. By heating the heating unit 20 and the internal space 10a before the raw materials are charged, the raw materials can be carbonized efficiently. It is preferable that the internal space 10a is heated to at least 200°C before the raw materials are charged.

[0039] Ignition unit 13 may be provided at a position capable of heating the upper part of heating unit 20, but is preferably provided at a position capable of heating the vicinity thereof, including apex 20a. Ignition unit 13 is preferably provided at a position higher than apex 20a of the heating unit. In addition, ignition unit 13 is preferably provided below inlet 11. Ignition unit 13 may be provided at multiple locations, not just one location.

[0040] The ignition unit 13 also serves as a device for igniting the input raw material in order to decompose and combust the raw material.

[0041] (Air supply port 10b) The air supply port 10b is provided on the side wall of the main body 10 to supply air from the outside of the carbonization furnace 1 to the internal space 10a. The air supply port 10b is provided below the input port 11 of the main body 10 and above the heating unit 20. The air supply ports 10b are preferably provided discretely around the entire circumference of the side wall of the main body 10. A device for feeding air into the internal space 10a while adjusting the amount of air supplied to the air supply port 10b is provided outside the carbonization furnace 1. The device includes, for example, a fan 101b.

[0042] The air supplied from the air supply port 10b promotes the decomposition and combustion of the raw material in the internal space 10a near the air supply port 10b. The space in the internal space 10a where the decomposition and combustion of the raw material is promoted is called the decomposition and combustion zone 10d. In the decomposition and combustion zone 10d, combustion of the pyrolysis gas generated by the decomposition and combustion (primary combustion of the pyrolysis gas) also occurs.

[0043] The solid content generated in the decomposition and combustion zone 10d descends through the internal space 10a as the treatment in the carbonization furnace 1 progresses.

[0044] On the other hand, the remainder of the pyrolysis gas generated in the decomposition and combustion zone 10d that is not combusted in the decomposition and combustion zone 10d rises in the internal space 10a.

[0045] (Air supply port 10c) The air supply port 10c is provided on the side wall of the main body 10 in order to supply air from the outside of the carbonization furnace 1 to the internal space 10a. The air supply port 10c is provided above the feed port 11 of the main body 10. The air supply ports 10c are preferably provided discretely around the entire circumference of the side wall of the main body 10. A device for feeding air into the internal space 10a while adjusting the amount of air supplied to the air supply port 10c is provided outside the carbonization furnace 1. The device includes, for example, a fan 101c.

[0046] Air supplied from the air supply port 10c promotes the "combustion" of the pyrolysis gas rising from the decomposition combustion zone 10d. In this specification, the combustion of the pyrolysis gas in the internal space 10a above the inlet 11 is sometimes referred to as "secondary combustion" in contrast to the combustion (primary combustion) of the pyrolysis gas in the decomposition combustion zone 10d. The space above the internal space 10a where the pyrolysis gas undergoes secondary combustion is referred to as the secondary combustion zone 10e.

[0047] It is preferable that the temperature in the vicinity of the secondary combustion zone 10e is 800°C or higher for the combustion of pyrolysis gas. The temperature in the vicinity of the secondary combustion zone 10e becomes higher as it approaches the upper part of the internal space 10a due to the heat of combustion of the pyrolysis gas. The upper limit of the temperature is not limited as long as it does not damage the carbonization furnace, but the temperature in the vicinity of the secondary combustion zone 10e is generally 1200°C or lower, more preferably 1150°C or lower. In addition, it is preferable to set the residence time of the pyrolysis gas in the secondary combustion zone 10e to 2 seconds or more, since this can reduce the generation of dioxins.

[0048] (Exhaust port 14) The exhaust port 14 is a component for discharging exhaust gas generated by burning the pyrolysis gas from the carbonization furnace 1. The exhaust port 14 is provided in the upper part of the main body 10. The exhaust port 14 is provided above the air supply port 10c.

[0049] (Air supply port 10f) The main body 10 may have an air supply port 10f. The air supply port 10f is provided on the side wall of the main body 10 to supply air from the outside of the carbonization furnace 1 to the internal space 10a. The air supply port 10f is provided below the air supply port 10b at a height where the heating unit 20 is provided. The air supply port 10f is preferably provided discretely around the entire circumference of the side wall of the main body 10. A device for feeding air into the internal space 10a while adjusting the amount of air supplied to the air supply port 10f is provided outside the carbonization furnace 1. The device includes, for example, a fan 101f.

[0050] The air supplied from the air supply port 10f promotes carbonization of the solid matter falling from the decomposition and combustion zone 10d. The space in the vicinity of the air supply port 10f in the internal space 10a where the solid matter is further carbonized is called the carbonization section 10g.

[0051] In the side wall of the main body 10, no air supply port is provided below the air supply port 10f.

[0052] The reaction in each part of the internal space 10a can be adjusted by the amount of air supplied into the carbonization furnace 1 through the air supply ports 10b, 10c, and 10f. This allows the reaction heat generated in each part of the internal space 10a to be controlled, and the temperature of the internal space 10a to be adjusted.

[0053] Materials that are commonly used as materials for carbonization furnaces can be used as the material for the main body 10. Examples of such materials include stainless steel.

[0054] (2) Heating section As described above, the heating unit 20 is heated by the ignition unit 13. The heating unit 20 is also heated by heat generated by decomposition combustion or combustion. The heating unit 20 stores heat and heats the solid content by radiation and heat transfer. The heating unit 20 promotes carbonization of the solid content to form a carbonized material. The heating unit 20 may have a heat source in addition to the heat obtained from the ignition unit 13 and the heat generated by decomposition combustion or combustion.

[0055] The heating unit 20 is provided below the internal space 10a of the main body 10. The apex 20a of the heating unit 20 is located below the input port 11.

[0056] The shape of the heating unit 20 is a cylinder with a closed upper end. As shown in Fig. 1, the shape of the upper part of the heating unit 20 is preferably a cone shape. The heating unit 20 may have an uneven surface. The heating unit 20 is provided coaxially with the main body 10.

[0057] The heating section 20 may include an air supply port 20b that supplies air to the carbonization furnace 1. The air supply port 20b is provided in the upper part of the heating section 20, and is not provided in the lower part of the heating section 20. The air supply port 20b is preferably provided at the same height as the air supply port 10f. This divides the space between the heating section 20 and the main body section 10 into a space with a large supply of air (carbonization section 10g) and a space with a small supply of air (non-combustible section 10h).

[0058] The air supplied to the carbonization section 10g from the air supply port 20b is sent from the outside of the carbonization furnace 1 through a space provided inside the shaft 21 of the heating section 20.

[0059] In the carbonization section 10g, the solids are further carbonized. Finally, the solids are decomposed into carbonized material and pyrolysis gas. Carbonization in the carbonization section 10g means that the carbonization is advanced by supplying air and maintaining a high temperature. This carbonization is also called "refining" or "ayashi". The generated pyrolysis gas rises in the internal space 10a.

[0060] The charcoal refined in the carbonization section 10g moves to the non-combustible section 10h below the carbonization section 10g. The charcoal that reaches the non-combustible section 10h is extinguished in the non-combustible section 10h where there is little air supply.

[0061] The heating section 20 may be rotatable around a central axis. By rotating, air can be uniformly supplied to the carbonization section 10g, and the carbonization efficiency and the purity of the carbonized material can be improved. The means for rotating the heating section 20 is not limited, but the shaft 21 and the heating section 20 may be connected and the shaft 21 may be rotated by a known driving means. The rotation speed may be appropriately adjusted depending on the type, composition, size, shape, etc. of the raw material.

[0062] The heating unit 20 may include a table 22 at the bottom. The table 22 is preferably in a truncated cone shape. The table 22 may be liftable and lowerable, and the distance between the table 22 and the main body 10 may be appropriately adjusted. By lifting and lowering the table 22, the carbide can be crushed between the table 22 and the main body 10, and the size of the carbide can be appropriately adjusted. The table 22 may be rotatable. The table 22 may be rotatable independently of the heating unit 20. A known means may be used for lifting and rotating the table 22.

[0063] The heating unit 20 may be removable from the bottom of the main body 10. Inside the carbonization furnace 1, clinker, which is mainly formed by cooling of dissolved silica, may be present. The clinker needs to be removed periodically because it may impair the performance of the carbonization furnace 1. If the heating unit 20 is removable, the work of removing the clinker is easy. A known means may be used as a means for removing the heating unit 20 from the bottom of the main body 10.

[0064] The size of the heating part 20 is set according to the size of the main body part 10. The difference between the inner radius of the main body part 10 and the outer radius of the heating part 20 (the width w of the space formed between the inner wall of the main body part 10 and the outer wall of the heating part 20) is 300 mm or less, preferably 200 mm or less. The lower limit of the width w is not particularly limited, but is preferably 50 mm or more. More preferably, it is 100 mm or more.

[0065] By reducing the width w, unevenness in the heat transfer from the heating part 20 to the charcoal can be suppressed, and homogeneous charcoal can be obtained. The decrease in the yield of charcoal caused by reducing the width w can be compensated for by increasing the height of the heating part 20.

[0066] Furthermore, materials that are commonly used as materials for heating parts can be used as the material for the heating part 20. Examples of such materials include stainless steel.

[0067] (3) Baffle FIG. 2 is a plan view showing the baffle 30, and is a cross-sectional view taken along line II-II in FIG.

[0068] The baffle 30 has a function of controlling the flow of pyrolysis gas rising from the decomposition and combustion zone 10d and the carbonization section 10g.

[0069] 2, the baffle 30 is an annular member provided around the entire circumference along the inner wall of the main body 10, and opens along an end 30a on the center side of the main body 10. In the carbonization furnace 1, the end 30a of the baffle 30 on the center side of the main body 10 contacts the heating part 20 in a plan view (FIG. 2(a)). Alternatively, the end 30a overlaps with the heating part 20 in a plan view (FIG. 2(b)).

[0070] (Baffle 30 position) The baffle 30 may be installed at a fixed height or may be installed at a changeable height. It is preferable that the baffle 30 is installed at a changeable height depending on the type, composition, size, shape, etc. of the raw material to be charged into the carbonization furnace 1.

[0071] The baffle 30 is provided at the same height as the apex 20a of the heating section or at a position higher than the apex 20a. The baffle 30 is preferably provided below the intermediate plane between the inner wall of the upper surface of the main body 10 and the apex 20a of the heating section 20. Depending on the size of the carbonization furnace 1, for example, the lowest part of the lower surface of the baffle 30 is located in a range of 0 mm to 400 mm above the apex 20a of the heating section 20. The vertical positional relationship between the baffle 30 and the input port 11 is not limited.

[0072] As shown in FIG. 1, the baffle 30 has an upper surface 30m and a lower surface 30n both parallel to the xy plane.

[0073] The baffle 30 may be coupled to the carbonization furnace 1. The baffle 30 may be removable from the carbonization furnace 1.

[0074] The baffle 30 may be provided in a plurality of layers at intervals on the inner wall of the main body 10. It is preferable that the baffle 30 is provided in a single layer on the inner wall of the main body 10.

[0075] (Baffle 30 shape) The distance from the end of the baffle 30 on the inner wall side of the main body 10 to the end 30a on the center side of the main body 10 in a plan view is shorter than the inner radius of the main body 10.

[0076] As described above, the pyrolysis gas generated in the carbonization furnace is combusted in the carbonization furnace to become exhaust gas, which is discharged outside the carbonization furnace 1. The combustion of the pyrolysis gas is likely to be incomplete if sufficient combustion time is not ensured or if there is a shortage of oxygen during combustion. If the pyrolysis gas is incompletely combusted, the exhaust gas discharged outside the carbonization furnace 1 will be mixed with black smoke, which is a problem.

[0077] In carbonization furnaces, it is necessary to increase the amount of carbonized material produced and improve productivity. On the other hand, the amount of pyrolysis gas generated increases with the increase in the amount of carbonized material produced, so it is relatively difficult to ensure sufficient combustion time, and the amount of oxygen becomes insufficient, making it more likely to cause the above-mentioned incomplete combustion.

[0078] As a result of extensive research into the above-mentioned problems, the inventors discovered that it is possible to control the flow of pyrolysis gas and promote the combustion of the pyrolysis gas by providing the baffle 30, and thus completed the present invention. Note that the inventors have hypothesized the mechanism of the function of the baffle 30 to be described below with reference to Figure 3, but the present invention is not limited to the hypothetical mechanism below.

[0079] Fig. 3 is a cross-sectional view showing the flow of pyrolysis gas in a carbonization furnace. Fig. 3(a) shows the flow of pyrolysis gas in a conventional carbonization furnace 1X having no baffle, and Fig. 3(b) shows the flow of pyrolysis gas in the carbonization furnace 1 of this embodiment. In Fig. 3, the flow of pyrolysis gas is indicated by arrows.

[0080] As described above, the pyrolysis gas G generated in the decomposition combustion zone 10d and the carbonization section 10g is burned while rising in the internal space 10a. Here, in the carbonization furnace 1X shown in Fig. 3(a), the pyrolysis gas G is not blocked from rising. Therefore, if the amount of pyrolysis gas G generated increases, it is difficult to ensure sufficient combustion time, and there is a risk that the pyrolysis gas G will not be burned completely.

[0081] 3(b), the baffle 30 partially blocks the flow of the pyrolysis gas G. Therefore, in the carbonization furnace 1, the pyrolysis gas G temporarily stays below the baffle 30 and then is collected at the opening of the baffle 30. In addition, a complex air current is generated below the baffle 30, and the pyrolysis gas is well mixed with the air.

[0082] This allows the pyrolysis gas to be burned suitably without a shortage of oxygen during combustion. Also, the pyrolysis gas is collected at the opening, which promotes combustion. Therefore, in the carbonization furnace 1, the combustion of the pyrolysis gas is promoted by the combustion in the lower part of the baffle 30 (i.e., the combustion in the decomposition combustion zone 10d) and the combustion in the secondary combustion zone 10e, and the generation of black smoke is suppressed.

[0083] (Modification) The shape of the baffle is not limited to the above-mentioned shape. Figures 4 and 5 are a plan view and a cross-sectional view showing modified examples of the baffle. Figure 4 shows the shape of the baffle in plan view.

[0084] 4(a) is provided so that it opens along an end 31a on the center side of the main body 10 and is provided so that a portion of the entire circumference of the inner wall of the main body 10 is missing. For example, when the baffle 31 is provided below the inlet 11, if the cutout portion (opening 31b) of the baffle 31 and the inlet 11 are arranged to overlap in the circumferential direction in a plan view, it is possible to obtain an effect of suppressing accumulation of raw material on the upper surface of the baffle 31. The cutout portion refers to the portion where the baffle is missing (i.e., the opening) compared to when the baffle is provided along the entire circumference of the inner wall of the main body 10.

[0085] The above effect can also be obtained with the baffle 32 shown in Fig. 4(b). The baffle 32 opens along an end 32a on the center side of the main body 10 and is provided around the entire circumference of the inner wall of the main body 10, but a part of the baffle 32 is recessed toward the inner wall of the main body 10 to form an opening 32b. Even with this type of baffle 32, the opening 32b of the baffle 32 and the feed port 11 are arranged to overlap in the circumferential direction in a plan view, so that accumulation of raw material on the upper surface of the baffle 32 can be suppressed.

[0086] The above effect can also be obtained with the baffle 33 shown in Fig. 4(c). The baffle 33 opens along the end 33a on the center side of the main body 10 and is provided around the entire circumference of the inner wall of the main body 10, but a part of the baffle 33 is separated from the inner wall of the main body 10 to form an opening 33b. That is, in the baffle 33, the opening surrounded by the end 33a and the opening 33b are not substantially connected, but are separated by the baffle 33. Even in such a baffle 33, the opening 33b of the baffle 33 and the feed port 11 are arranged to overlap in the circumferential direction in a plan view, so that accumulation of raw material on the upper surface of the baffle 33 can be suppressed.

[0087] The baffle may be composed of a plurality of members. Baffle 34 shown in Fig. 4(d) is formed by connecting a plurality of baffle pieces 341, 342, 343, 344, 345, and 346 without gaps along the circumferential direction of the inner wall of main body 10. Baffle 34 is open along end 34a on the center side of main body 10.

[0088] 4(e) has a plurality of baffle pieces 351, 352, 353, 354, 355, 356 formed along the circumferential direction of the inner wall of the main body 10 with adjacent baffle pieces spaced apart. The baffle 35 is open along an end 35a on the center side of the main body 10.

[0089] In the case of a configuration such as the baffles 34 and 35, even if part of the baffle is damaged during use of the carbonization furnace 1, it can be repaired by replacing the baffle piece including the damaged part, which makes maintenance easy.

[0090] Furthermore, although the openings of the baffles 30, 31, 32, 33, 34, and 35 described above have a circular shape in plan view, the shape of the openings is not limited to this. For example, the openings may have a polygonal shape.

[0091] Fig. 5 shows the cross-sectional shape of the baffle. In the baffle 37 shown in Fig. 5(a), the end 37a on the center side of the main body 10 is raised upward, and both the upper surface 37m and the lower surface 37n of the baffle intersect with the xy plane.

[0092] 5(b), an upper surface 38m is parallel to the xy plane, and a lower surface 38n intersects with the xy plane. An opening surrounded by an end 38a on the center side of the main body 10 is parallel to the upper surface 38m.

[0093] 5(c), the baffle 39 has an upper surface 39m parallel to the xy plane and a lower surface 39n that is a curved surface that is convex downward. The opening surrounded by the end 39a on the center side of the main body 10 is parallel to the upper surface 39m.

[0094] As shown in Figures 5(a) to (c), the lower surface of the baffle intersects the xy plane or is a curved surface that is convex downward, thereby achieving the effect that the pyrolysis gas does not remain stagnant on the lower surface of the baffle (i.e., the decomposition combustion zone 10d) but rises in the internal space 10a.

[0095] The material constituting the baffle 30 may be any known material. The material is preferably a castable refractory. More preferably, the material is fireproof concrete. The fireproof concrete is preferably cast into a formwork.

[0096] <Gasification system> The carbonized material produced by the carbonization furnace 1 and the exhaust gas discharged from the carbonization furnace 1 may then be supplied to a reformer. The reformer is a structure in which the carbonized material is reacted with superheated steam at high temperature and high pressure to obtain water gas and activated carbon. As one embodiment of the present invention, a gasification system including a carbonization furnace and a reformer is provided.

[0097] Fig. 6 is a block diagram showing an embodiment of a gasification system. The arrows in Fig. 6 indicate the flow of materials in each process. As shown in Fig. 6, a gasification system 400 of this embodiment includes a dryer 401, a carbonization furnace 1, a reforming furnace 402, a first cyclone 403, a second cyclone 404, a superheater 405, a first heat exchanger 406, a second heat exchanger 407, a third heat exchanger 408, a bag filter 409, and a gas tank 410.

[0098] Dryer 401 removes moisture from the raw material using high-temperature air A1 as a drying heat source. The moisture content of the raw material fed into dryer 401 is preferably 50% by mass or less. The moisture content of the raw material after drying in dryer 401 is preferably 10% by mass or more and 20% by mass or less. More preferably, it is 15% by mass or more and 20% by mass or less.

[0099] The carbonization furnace 1 produces carbonized material and pyrolysis gas from the dried raw material. The pyrolysis gas that has been combusted and treated is called exhaust gas E1.

[0100] The reformer 402 reacts the carbonized material produced in the carbonization furnace 1 with superheated steam V2 to generate water gas G1 and activated carbon. In addition, exhaust gas E1 is introduced as a heat source into the reformer 402. The reformer 402 discharges exhaust gas E2, the temperature of which has been reduced from the exhaust gas E1.

[0101] The first cyclone 403 removes pulverized coal and dust contained in the water gas G1 to produce water gas G2. The second cyclone 404 removes impurities contained in the exhaust gas E2 discharged from the reformer 402 to produce exhaust gas E3.

[0102] The superheater 405 heats the steam V1 by heat exchange with the exhaust gas E3 to generate superheated steam V2. Meanwhile, the exhaust gas E3 is heat exchanged with the steam V1 by heating it to become the exhaust gas E4.

[0103] The first heat exchanger 406 generates water gas G3 from the water gas G2. The first heat exchanger 406 is a so-called dry heat exchanger that cools the water gas G2 by transferring heat to a fluid having a lower temperature than the water gas G2, without the water gas G2 coming into direct contact with water.

[0104] The second heat exchanger 407 heats the air A0 by exchanging heat with the exhaust gas E4 to generate high-temperature air A1. Meanwhile, the exhaust gas E4 is heat-exchanged by heating the air A0 to become the exhaust gas E5, which is discharged to the outside.

[0105] The third heat exchanger 408 heats the water W1 by exchanging heat with a portion of the high-temperature air A1, and generates water vapor V1.

[0106] The bag filter 409 collects fine activated carbon contained in the water gas G3 and turns it into water gas G4.

[0107] The gas tank 410 stores water gas G4.

[0108] The carbonization furnace and gasification system of the present embodiment are excellent in combustion of pyrolysis gas, and therefore useful as a carbonization furnace and a gasification system.

[0109] According to the carbonization furnace 1 configured as above, it is possible to promote the combustion of the pyrolysis gas generated in the carbonization process, and to suppress the problem of black smoke being mixed into the exhaust gas discharged.

[0110] Moreover, according to the gasification system 400 having the above-mentioned configuration, this gasification system is a gasification system that effectively utilizes the carbonization furnace 1 and exhaust gas.

[0111] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiment. The shapes and combinations of the components shown in the above embodiment are merely examples, and various modifications can be made based on the design, specifications, etc., without departing from the spirit of the present invention. [Explanation of symbols]

[0112] 1: carbonization furnace, 10: main body, 11: inlet, 12: outlet, 13: ignition section, 14: exhaust port, 10a: internal space, 10b: air supply port, 101b: fan, 10c: air supply port, 101c: fan, 10d: decomposition combustion zone, 10e: secondary combustion zone, 10f: air supply port, 101f: fan, 10g: carbonization section, 10h: non-combustible section, w: width of space, 20: heating section, 21: shaft, 22: table, 20a: apex, 20b: air supply port, 30-39: baffle, 30a-39a: edge, G: pyrolysis gas 31b-33b: baffle openings, 30m, 37m-39m: upper surface, 30n, 37n-39n: lower surface, 400: gasification system, 401: dryer, 402: reformer, 403: first cyclone, 404: second cyclone, 405: superheater, 406: first heat exchanger, 407: second heat exchanger, 408: third heat exchanger, 409: bag filter, 410: gas tank, E1-E5: exhaust gas, V1: steam, V2: superheated steam, G1-G4: water gas, A0: air, A1: high temperature air, W1: water

Claims

1. A cylindrical main body portion extending in a vertical direction and having an internal space; A heating unit provided below the internal space, The heating unit is a cylindrical member having a closed upper end, and is disposed coaxially with the main body unit. The side wall of the main body has an inlet for injecting raw material into the internal space, A first air supply port is provided below the inlet and at a height equal to the height of the apex of the heating unit or above the heating unit; A second air supply port is provided above the input port, A carbonization furnace in which no air supply port is provided in a side wall of the main body at a position facing downwardly of the heating section.

2. The carbonization furnace according to claim 1 , wherein the first air supply ports are provided discretely around the entire circumference of the side wall of the main body.

3. The carbonization furnace according to claim 1 or 2, wherein the side wall of the main body has a third air supply port provided below the first air supply port and at a height where the heating section is provided.

4. The carbonization furnace according to claim 1 or 2, wherein the heating section has an air supply port for supplying air to the internal space.

5. The heating unit has a heating unit air supply port that supplies air to the internal space, The carbonization furnace according to claim 3 , wherein the heating section air supply port is provided at the same height as the third air supply port.

6. Equipped with an ignition unit, The carbonization furnace according to claim 1 , wherein the ignition portion is provided at a position higher than a top of the heating portion.

7. The carbonization furnace according to any one of claims 1 to 6; a reforming furnace for obtaining water gas and activated carbon from the carbonized material produced in the carbonization furnace and superheated steam.

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