Fertilizer production system and fertilizer production method

Abstract

To provide a fertilizer production system and a fertilizer production method for producing fertilizer using incineration ash.SOLUTION: The fertilizer production system comprises a recovery device of volatilizing heavy metal included in incineration ash under a temperature condition of a prescribed temperature or more to separate the heavy metal included in the incineration ash to recover the incineration ash removed of the heavy metal, an adding device of adding an auxiliary agent including a prescribed component to the incineration ash recovered in the recovery device, and a granulation device of granulating the incineration ash with the auxiliary agent added thereto, to produce fertilizer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fertilizer production system and a fertilizer production method. [Background technology]

[0002] For example, various techniques have been proposed for treating exhaust gas from incinerators that incinerate sewage sludge (hereinafter also referred to simply as sludge or material to be incinerated) (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-221206 A Summary of the Invention [Problem to be solved by the invention]

[0004] Here, the exhaust gas discharged from the incinerator includes, for example, incineration ash generated by incinerating the incineration target (hereinafter, simply referred to as incineration ash). In an incineration system including the incinerator (for example, a sewage treatment facility that treats sewage sludge), for example, it is required to reduce the amount of waste discharged.

[0005] Therefore, in the incineration system described above (hereinafter also simply referred to as the incineration system), it is desirable to effectively utilize the incineration ash contained in the exhaust gas for other purposes. Specifically, in the incineration system described above, it is desirable to manufacture fertilizer using the incineration ash. [Means for solving the problem]

[0006] The fertilizer manufacturing system in the present invention includes a recovery device that separates heavy metals from the incineration ash by volatilizing the heavy metals contained in the incineration ash in a temperature state of a predetermined temperature or higher and recovers the incineration ash from which the heavy metals have been separated, an addition device that adds an auxiliary agent containing a predetermined component to the incineration ash recovered by the recovery device, and a granulation device that manufactures fertilizer by granulating the incineration ash to which the auxiliary agent has been added.

Advantages of the Invention

[0007] According to the fertilizer manufacturing system and the fertilizer manufacturing method in the present invention, it becomes possible to manufacture fertilizer using incineration ash.

Brief Description of the Drawings

[0008] [Figure 1] FIG. 1 is a diagram for explaining a configuration example of an incineration system 1000 in the first embodiment. [Diagram 2] FIG. 2 is a diagram for explaining the hardware configuration of the control device 10. [Diagram 3] FIG. 3 is a flowchart for explaining the fertilizer manufacturing method in the first embodiment. [Figure 4] FIG. 4 is a flowchart for explaining the auxiliary agent identification control in the first embodiment.

Modes for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, such description should not be construed in a limiting sense and does not limit the subject matter described in the claims. Also, various changes, substitutions, and modifications can be made without departing from the spirit and scope of the present disclosure. Further, different embodiments can be appropriately combined.

[0010] [Incineration System 1000 in the First Embodiment] First, an incineration system 1000 in the first embodiment will be described. Fig. 1 is a diagram for explaining a configuration example of the incineration system 1000 in the first embodiment. Note that the arrangement positions, lengths, and numbers of pipes shown below are examples and are not limited to these.

[0011] 1, the incineration system 1000 includes, for example, an incinerator 1, a recovery device 2, a blower B1, a storage tank 3a, a pump P1, and a fertilizer granulation device 4 (hereinafter also simply referred to as the granulation device 4). Hereinafter, the storage tank 3a and the pump P1 are also collectively referred to as the addition device 3. Hereinafter, the addition device 3 and the granulation device 4 are also collectively referred to as the fertilizer production system 100.

[0012] The blower B1 is, for example, a device that supplies air (hereinafter also referred to as combustion air) to the incinerator 1 via a line L21. The line L21 is, for example, a pipe that connects the outlet side of the blower B1 to the inlet side of the combustion air in the incinerator 1. Specifically, the blower B1 is, for example, a device having a function of blowing air, such as a fan or a blower.

[0013] The incinerator 1 is, for example, a fluidized bed incinerator that incinerates sludge (dehydrated cake) supplied via a line L11, and has a so-called fluidized bed 1a. The line L11 is, for example, a pipe that connects a upstream facility of the incinerator 1 (for example, a sludge dryer) with the inlet side of the incinerator 1 for sludge.

[0014] The recovery device 2 is, for example, disposed downstream of the incinerator 1, and is a device that recovers incineration ash contained in the exhaust gas G1 supplied from the incinerator 1 via a line L1. The line L1 is, for example, a pipe that connects the outlet side of the exhaust gas G1 in the incinerator 1 with the inlet side of the exhaust gas G1 in the recovery device 2.

[0015] Specifically, the recovery device 2 is, for example, a high-temperature cyclone. The recovery device 2 separates the heavy metals from the incineration ash (solid-gas separation) by volatilizing the heavy metals contained in the incineration ash at a high temperature of, for example, 800°C or higher, and recovers the incineration ash from which the heavy metals have been separated. The heavy metals here are, for example, arsenic, mercury, chromium, cadmium, nickel, and lead.

[0016] That is, in the incineration system 1000 of this embodiment, for example, by arranging the recovery device 2 upstream of a heat exchanger (not shown) that recovers the heat contained in the exhaust gas G1, the exhaust gas G1 (exhaust gas G1 before the heat contained therein is recovered by the heat exchanger) that maintains a high temperature state of 800°C or higher is supplied to the recovery device 2.

[0017] As a result, the recovery device 2 in this embodiment can, for example, recover incineration ash contained in the exhaust gas G1 under conditions in which heavy metals contained in the incineration ash are volatilized. Therefore, in the fertilizer production system 100 in this embodiment, for example, it is possible to suppress the amount of heavy metals contained in the incineration ash recovered in the recovery device 2. Therefore, in the fertilizer production system 100, for example, it is possible to produce fertilizer that can be used for agricultural land in addition to being used for green space (non-agricultural land).

[0018] Furthermore, heavy metals contained in incineration ash tend to be contained in larger amounts in incineration ash with smaller particle sizes than in incineration ash with larger particle sizes, for example. Therefore, in the fertilizer production system 100 of this embodiment, for example, a high-temperature cyclone is used as the recovery device 2 to recover incineration ash with a particle size equal to or larger than a predetermined size.

[0019] As a result, in the fertilizer production system 100 of this embodiment, it is possible to suppress the recovery of incineration ash containing a large amount of heavy metals (incineration ash with a particle size smaller than a predetermined value). Therefore, in the fertilizer production system 100, it is possible to further suppress the amount of heavy metals contained in the incineration ash recovered in the recovery device 2, for example.

[0020] Returning to Fig. 1, the recovery device 2 supplies the exhaust gas G1 (exhaust gas G1 after incineration ash is recovered) to downstream equipment (not shown) of the recovery device 2, for example, via a line L2. The line L2 is, for example, a pipe that connects the outlet side of the exhaust gas G1 in the recovery device 2 to the downstream equipment.

[0021] Moreover, the recovery device 2 supplies the incineration ash to the granulation device 4 via, for example, a line L3. The line L3 is, for example, a pipe that connects the recovery device 2 and the granulation device 4.

[0022] The incineration system 1000 may further include, as downstream equipment of the recovery device 2, a dust collector (not shown) for removing dust in the flue gas G1 (the flue gas G1 after the incineration ash has been recovered) discharged from the recovery device 2, a heat exchanger (not shown) for recovering the heat contained in the flue gas G1, and a SO X The flue gas treatment tower may also have a flue gas treatment tower (not shown) that removes such components by incorporating them into smoke washing water, and a chimney (not shown) that releases the exhaust gas G1 cleaned in the flue gas treatment tower to the outside.

[0023] The storage tank 3a stores, for example, an auxiliary agent (hereinafter, simply referred to as an auxiliary agent) to be added to the incineration ash recovered in the recovery device 2. The auxiliary agent is, for example, water or a liquid binder. That is, the auxiliary agent is, for example, an auxiliary agent added in the granulation device 4 to form (granulate) the incineration ash into a predetermined particle size.

[0024] When a liquid binder containing organic matter such as blackstrap molasses or dextrin is used as an auxiliary agent, the fertilizer production system 100 can produce, for example, a fertilizer that can increase the activity of useful microorganisms in soil (i.e., a fertilizer with high fertilizer effect). The auxiliary agent may be a powder containing organic matter such as dextrin.

[0025] The auxiliary may be, for example, an auxiliary containing one or more fertilizer effective components (hereinafter also referred to as predetermined components) that are not contained in the incineration ash, among one or more components that need to be contained in the fertilizer produced in the granulation device 4 (for example, one or more components necessary for the growth of the plant to which the fertilizer is used). Specifically, the predetermined component may be, for example, one that contains organic matter. The predetermined component may be, for example, one that contains nitrogen or potassium.

[0026] That is, the fertilizer production system 100 in this embodiment may produce fertilizer by using incineration ash to which an auxiliary agent containing a necessary fertilizer component has been added, for example.

[0027] This makes it possible for the fertilizer production system 100 in this embodiment to produce a fertilizer containing necessary components, for example.

[0028] Hereinafter, the auxiliary agent will be described as being liquid, but is not limited thereto. Specifically, the auxiliary agent may be, for example, in powder form.

[0029] The pump P1 is disposed, for example, in the line L4, and supplies (adds) the auxiliary agent stored in the storage tank 3a to the granulation device 4 in an amount and at a timing designated in advance by the manager of the incineration system 1000 (hereinafter also simply referred to as the manager). The line L4 is, for example, a pipe that connects the storage tank 3a and the granulation device 4.

[0030] The fertilizer production system 100 may have, for example, a plurality of storage tanks 3a. In this case, the plurality of storage tanks 3a may store, for example, a plurality of types of auxiliary agents (a plurality of types of auxiliary agents having different component configurations) that have been produced in advance. Furthermore, in this case, the granulation device 4 may be supplied with, for example, any of the plurality of types of auxiliary agents stored in the plurality of storage tanks 3a.

[0031] In addition, the incineration system 1000 will be described below as having a pump P1, but is not limited to this. Specifically, the incineration system 1000 may have, for example, a screw conveyor as a device for supplying an auxiliary agent to the incineration ash. In addition, the incineration system 1000 may have, for example, a syringe-type supply device, a piston-type supply device, or a rotary-type supply device as a device for supplying an auxiliary agent to the incineration ash.

[0032] The granulation device 4, for example, mixes and stirs incineration ash supplied from the recovery device 2 via line L3 with auxiliary agents supplied from pump P1 via line L4, and then granulates the mixture to produce fertilizer in the form of pellets, spheres, cylinders, flattened spheres, etc. (hereinafter, these are collectively referred to as pellets, etc.).

[0033] Specifically, the granulator 4 has, for example, a pan-type granulator (not shown) which is a rolling type granulator, or a briquette (not shown) which is a pressurized type granulator. The granulator 4 produces, for example, pellet-shaped fertilizer having a porous structure.

[0034] In addition, the incineration system 1000 may have a water supply device (not shown) that supplies water (a small amount of water) to the granulation device 4, for example, when the auxiliary agent is in powder form, due to the need to mix and stir the incineration ash and the auxiliary agent.

[0035] Moreover, the incineration system 1000 may further include, for example, a measuring device M1 and a control device 10, as shown in FIG.

[0036] In this case, the measuring device M1 may be, for example, a device that measures each component constituting the incineration ash discharged from the recovery device 2. Specifically, the measuring device M1 may be, for example, a device that measures the amount of each component contained in the incineration ash per unit amount.

[0037] In this case, the control device 10 may perform control to specify the auxiliary agent to be added to the incineration ash by the addition device 3 based on the measurement results of the components of the incineration ash by the measurement device M1 at a predetermined timing (hereinafter, also referred to as auxiliary agent specification control). The predetermined timing here may be, for example, a regular timing such as once every few days.

[0038] Specifically, the control device 10 may, for example, identify an auxiliary agent that contains at least one or more components that are not measured by the measurement device M1 among multiple types of auxiliary agents that have been produced in advance and stored in each of the multiple storage tanks 3a. Then, the control device 10 may, for example, instruct the pump P1 to add the identified auxiliary agent.

[0039] Furthermore, the control device 10 may, for example, identify an auxiliary that contains at least one or more components not measured by the measuring device M1 and one or more components whose amounts measured by the measuring device M1 are less than the corresponding threshold values ​​among the multiple types of auxiliary produced in advance and stored in each of the multiple storage tanks 3a. The threshold values ​​here may, for example, be the amounts of each component that need to be included in the fertilizer produced in the granulating device 4. The control device 10 may, for example, instruct the pump P1 to add the identified auxiliary.

[0040] That is, the properties of the incineration ash contained in the exhaust gas G1 may change, for example, depending on the season, weather, etc. Therefore, the control device 10 in this embodiment may change the auxiliary agent added to the granulator 4 (incineration ash) as necessary, for example, by periodically performing auxiliary agent specification control.

[0041] As a result, the fertilizer production system 100 in this embodiment is able to stably produce fertilizer containing necessary components even if the composition of the components in the incineration ash changes depending on, for example, the season, the weather, etc.

[0042] The operator may, for example, manually measure each component constituting the incineration ash discharged from the recovery device 2. Then, the operator may, for example, determine (select) the auxiliary agent to be added to the incineration ash by the addition device 3 based on the results of the manual measurement.

[0043] The fertilizer production system 100 may also include an auxiliary agent generating device (not shown) that generates a new auxiliary agent to be added to the incineration ash by the addition device 3 based on the measurement results of the components of the incineration ash by the measurement device M1, for example.

[0044] Specifically, the auxiliary agent generating device may generate a new auxiliary agent including at least one or more components not measured by the measuring device M1. The control device 10 may instruct the pump P1 to add the generated new auxiliary agent. The configuration of the control device 10 in the first embodiment will be described below.

[0045] [Control device 10 in the first embodiment] FIG. 2 is a diagram illustrating the hardware configuration of the control device 10. As shown in FIG.

[0046] The control device 10 is, for example, an electronic device having an electronic circuit, as shown in Fig. 2. Specifically, the control device 10 is, for example, a computer device having a CPU 101 which is a processor, a memory 102, a communication device 103, and a storage medium 104. Each part is connected to each other, for example, via a bus 105.

[0047] The storage medium 104 has, for example, a program storage area (not shown) that stores a program 110 for performing auxiliary agent specific control. The storage medium 104 also has, for example, an information storage area 130 that stores information used when performing auxiliary agent specific control. The storage medium 104 may be, for example, a hard disk drive (HDD) or a solid state drive (SSD).

[0048] The CPU 101 performs auxiliary agent specification control by, for example, executing a program 110 loaded from the storage medium 104 to the memory 102 .

[0049] The communication device 103 accesses an operation terminal (not shown) through which an operator inputs necessary information, for example, via a network (not shown) such as the Internet.

[0050] The control device 10 may have, for example, a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). The control device 10 may include, for example, a peripheral interface controller (PIC). The auxiliary agent specific control may be executed, for example, in the FPGA or the ASIC.

[0051] [Fertilizer manufacturing method according to the first embodiment] Next, a description will be given of the fertilizer producing method according to the first embodiment. Fig. 3 is a flow chart illustrating the fertilizer producing method according to the first embodiment.

[0052] The recovery device 2 separates heavy metals from the incineration ash contained in the exhaust gas G1, for example, by volatilizing the heavy metals contained in the incineration ash at a temperature equal to or higher than a predetermined temperature, and recovers the incineration ash from which the heavy metals have been separated (step S1 in FIG. 3).

[0053] Specifically, the recovery device 2 recovers incineration ash from which heavy metals have been separated, for example, by continuously carrying out step S1 on the exhaust gas G1 that is continuously discharged from the incinerator 1 via the line L1.

[0054] Then, the recovery device 2 supplies the incineration ash recovered in step S1 to the granulation device 4 (step S2 in FIG. 3), for example.

[0055] Specifically, the recovery device 2 may supply the incineration ash recovered in step S1 to the granulation device 4 through a line L3 from an ash discharge port (not shown) provided in the recovery device 2. The line L3 may be provided with, for example, a supply device (not shown) that supplies the incineration ash in the recovery device 2, a storage hopper (not shown) that temporarily stores the incineration ash supplied by the supply device, and a valve (not shown) that controls the supply of the incineration ash from the storage hopper to the granulation device 4.

[0056] Next, the addition device 3 adds, for example, an auxiliary agent to the incineration ash supplied to the granulation device 4 in step S2 (step S3 in FIG. 3).

[0057] Specifically, the pump P1 supplies the auxiliary agent stored in the storage tank 3a to the granulator 4 through the line L4, for example.

[0058] Thereafter, the granulator 4 produces fertilizer by granulating the incineration ash to which the auxiliary agent has been added in step S3 (step S4 in FIG. 3).

[0059] Specifically, the granulator 4 mixes and stirs the incineration ash supplied in step S2 and the auxiliary agent added in step S3, and then performs dry granulation to produce pellet-shaped fertilizer.

[0060] [Flow chart of auxiliary agent specific control] Next, a description will be given of auxiliary agent specific control in the control device 10. Fig. 4 is a flow chart diagram illustrating auxiliary agent specific control in the first embodiment.

[0061] As shown in FIG. 4, the control device 10 acquires, for example, each component of the incineration ash measured by the measuring device M1 (step S11 in FIG. 4).

[0062] Then, the control device 10 identifies, for example, among multiple types of auxiliary agents that have been produced in advance and stored in each of the multiple storage tanks 3a, auxiliary agents that contain at least one or more components that were not measured by the measuring device M1 (step S12 in FIG. 4).

[0063] Thereafter, the control device 10 sets, for example, information indicating the type of auxiliary agent identified in step S12 to the pump P1 as information indicating the type of auxiliary agent to be added to the incineration ash supplied to the granulation device 4 (step S13 in FIG. 4). Then, the pump P1 adds, for example, the type of auxiliary agent indicated by the information set in step S13 to the incineration ash supplied to the granulation device 4.

[0064] The control device 10 may, for example, perform step S11, step S12, and step S13 consecutively. Specifically, the control device 10 may, for example, perform step S12 and step S13 consecutively in response to performing step S11. The control device 10 may, for example, perform step S11, step S12, and step S13 with a time interval between each of the steps. Specifically, the control device 10 may, for example, perform step S11, step S12, and step S13 at a time that is predetermined for each step.

[0065] Thus, the incineration system 1000 in this embodiment includes a recovery device 2 that, for example, separates heavy metals from the incineration ash by volatilizing the heavy metals contained in the incineration ash at a temperature state equal to or higher than a predetermined temperature, and recovers the incineration ash from which the heavy metals have been separated. The incineration system 1000 also includes an addition device 3 that adds an auxiliary agent containing a predetermined component to the incineration ash recovered in the recovery device 2. The incineration system 1000 also includes a granulation device 4 that produces fertilizer by granulating the incineration ash to which the auxiliary agent has been added.

[0066] Specifically, the recovery device 2 recovers, for example, incineration ash having a particle size equal to or smaller than a predetermined size. The recovery device is, for example, a high-temperature cyclone.

[0067] The incineration ash recovered by the recovery device 2 is, for example, incineration ash contained in exhaust gas discharged from an incinerator 1 that incinerates materials to be incinerated, such as sludge.

[0068] The predetermined component contained in the auxiliary agent is, for example, one or more components contained in the fertilizer, the amount of which contained in the incineration ash is less than the threshold value corresponding to each component. The incineration system 1000 is equipped with, for example, a control device 10 that identifies the predetermined component based on the components contained in the incineration ash. Furthermore, the addition device 3 adds, for example, an auxiliary agent that contains at least the predetermined component identified by the control device 10 to the incineration ash.

[0069] That is, in the incineration system 1000 of this embodiment, for example, the recovery device 2 is arranged upstream of a heat exchanger (not shown) that recovers the heat contained in the exhaust gas G1, and the exhaust gas G1 maintained at a high temperature of 800°C or higher is supplied to the recovery device 2.

[0070] As a result, the recovery device 2 in this embodiment can, for example, recover incineration ash contained in the exhaust gas G1 under conditions in which heavy metals contained in the incineration ash are volatilized. Therefore, in the fertilizer production system 100 in this embodiment, for example, it is possible to suppress the amount of heavy metals contained in the incineration ash recovered in the recovery device 2. Therefore, in the fertilizer production system 100, for example, it is possible to produce fertilizer that can be used for agricultural land in addition to being used for green space (non-agricultural land).

[0071] Furthermore, heavy metals contained in incineration ash tend to be contained in larger amounts in incineration ash with smaller particle sizes than in incineration ash with larger particle sizes, for example. Therefore, in the fertilizer production system 100 of this embodiment, for example, a high-temperature cyclone is used as the recovery device 2 to recover incineration ash with a particle size equal to or larger than a predetermined size.

[0072] As a result, in the fertilizer production system 100 of this embodiment, it is possible to suppress the recovery of incineration ash that contains a large amount of heavy metals, for example. Therefore, in the fertilizer production system 100, it is possible to suppress the amount of heavy metals contained in the incineration ash recovered in the recovery device 2, for example.

[0073] Furthermore, in the fertilizer production system 100 of this embodiment, for example, it is possible to reduce the amount of heavy metals contained in the incineration ash recovered in the recovery device 2, thereby eliminating the need to perform processing to further remove heavy metals contained in the recovered incineration ash (for example, washing the incineration ash with water).

[0074] Therefore, in the fertilizer production system 100 of this embodiment, it is possible to prevent, for example, the outflow of fertilizer components contained in the incineration ash (for example, the outflow of water-soluble fertilizer components). Also, in the fertilizer production system 100, for example, it is not necessary to dry the incineration ash after washing with water, and it is possible to reduce the energy required for producing fertilizer (the energy required for drying the incineration ash). Furthermore, in the fertilizer production system 100, it is not necessary to provide each piece of equipment for washing the incineration ash with water after collection, and it is possible to reduce the costs required for introducing each piece of equipment and the costs required for maintaining each piece of equipment, for example. [Explanation of symbols]

[0075] 1: Incinerator 1a: Fluidized bed 2: Recovery device 3: Addition device 3a: Storage tank 4: Granulator 10: Control device 100: Fertilizer production system 101: CPU 102: Memory 103: Communication device 104: Storage medium 105: Bus 1000: Incineration system B1: Blower L1: Line L2: Line L3: Line L4: Line L11: Line L21: Line M1: Measuring device P1: Pump

Claims

1. A recovery device that separates heavy metals from the incineration ash by volatilizing the heavy metals contained in the incineration ash at a temperature state equal to or higher than a predetermined temperature, and recovers the incineration ash from which the heavy metals have been separated; An addition device that adds an auxiliary agent containing a predetermined component to the incineration ash recovered in the recovery device; and a granulation device that produces fertilizer by granulating the incineration ash to which the auxiliary has been added.

2. By volatilizing the heavy metals contained in the incineration ash at a temperature equal to or higher than a predetermined temperature, the heavy metals are separated from the incineration ash, and the incineration ash from which the heavy metals have been separated is recovered; Adding an auxiliary agent containing a predetermined component to the recovered incineration ash, A fertilizer production method comprising granulating the incineration ash to which the auxiliary has been added to produce a fertilizer.

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