WO2023008522A1

WO2023008522A1 - Combustion device, and combustion method

Info

Publication number: WO2023008522A1
Application number: PCT/JP2022/029088
Authority: WO
Inventors: 一芳伊藤
Original assignee: 住友重機械工業株式会社
Priority date: 2021-07-29
Filing date: 2022-07-28
Publication date: 2023-02-02
Also published as: KR20240042607A; AU2022316664A1; JPWO2023008522A1

Abstract

As this combustion device, a circulating fluidized bed boiler comprises: a furnace (11) that generates combustion; a hydrogen storage material supply unit (14) that supplies, to the furnace (11), a granular hydrogen storage material such as a hydrogen occlusion alloy capable of releasing stored hydrogen when heated; a fluidized material circulation unit (3) that collects the granular hydrogen storage material that has left the furnace (11) and returns same to the interior of the furnace (11); a recovery unit (17) that recovers the hydrogen storage material from the bottom of the furnace (11); and a fuel supply unit (15) that supplies, to the furnace (11), fuel that is different from the hydrogen storage material. The hydrogen storage material is a hydrogen occlusion alloy. The hydrogen storage material is granular. A pulverization unit is further provided for pulverizing, into a granular form, the hydrogen storage material before same is supplied to a combustion chamber.

Description

Combustion device, combustion method

The present invention relates to a combustion device that generates combustion.

Combustion devices that generate combustion include a fluidized bed (BFB: Bubbling Fluidized Bed) boiler and a circulating fluidized bed that burns fuel through a fluidized bed or fluidized bed formed by a fluidized material such as silica sand that flows in the combustion chamber. (CFB: Circulating Fluidized Bed) boilers are known. Patent Literature 1 discloses a CFB boiler.

JP 2012-255612 A

BFB boilers and CFB boilers can achieve high combustion efficiency by using a high-temperature fluid material that flows in the combustion chamber as a medium. It is suitable for burning fuels of unstable quality such as tires, etc., and flame-retardant fuels. However, since these fuels are mainly composed of carbon, they generate greenhouse gases such as carbon dioxide when burned, which may further exacerbate global warming.

The present invention has been made in view of these circumstances, and its purpose is to provide a combustion apparatus capable of reducing the generation of greenhouse gases.

In order to solve the above problems, a combustion apparatus according to one aspect of the present invention includes a combustion chamber that generates combustion, and a hydrogen storage material supply unit that supplies a hydrogen storage material capable of releasing stored hydrogen when heated to the combustion chamber. , provided. Even if the hydrogen released from the hydrogen storage material is burned in the combustion chamber, it is mainly water that is produced, so that the generation of greenhouse gases can be reduced.

Another aspect of the present invention is a combustion method. This method includes a hydrogen storage material supply step of supplying a hydrogen storage material capable of releasing stored hydrogen when heated to a combustion chamber, and a combustion step of burning the hydrogen released from the hydrogen storage material in the combustion chamber.

It should be noted that any combination of the above constituent elements, and any conversion of the expression of the present invention between methods, devices, systems, recording media, computer programs, etc. are also effective as embodiments of the present invention.

According to the present invention, it is possible to reduce the generation of greenhouse gases in the combustion device.

1 shows the overall configuration of a circulating fluidized bed boiler; The overall configuration of the rotary kiln is shown.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description and drawings, the same or equivalent components, members, and processes are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate. The scales and shapes of the illustrated parts are set for convenience in order to facilitate explanation, and should not be construed as limiting unless otherwise specified. The embodiments are illustrative and do not limit the scope of the invention in any way. Individual features and combinations thereof described in the embodiments are not necessarily essential to the invention.

The combustion device of the present invention is any device that generates combustion. For example, when the combustion apparatus is configured as a boiler, the hydrogen released from the hydrogen storage material is supplied through a fluidized bed or a fluidized bed formed by a fluidized material such as silica sand flowing in the combustion chamber or a granular hydrogen storage material described later. The combustion device can be configured as a BFB boiler or a CFB boiler that burns the fuel containing. The combustion device can also be configured as a rotary kiln. In this embodiment, configuration examples of a CFB boiler and a rotary kiln will be specifically described.

Fig. 1 shows the overall configuration of a CFB boiler (circulating fluidized bed boiler) as a combustion device. In the CFB boiler, the fuel containing hydrogen released from the hydrogen storage alloy is supplied and burned in the furnace 11 in which fluid materials such as silica sand and granular hydrogen storage alloy flow, and the fuel generated in the combustion unit 1 The fluidized material is supplied to the steam generation unit 2 that generates steam from water by heat, the fluidized material circulation unit 3 as a circulation unit that collects the fluidized material that has come out of the furnace 11 and returns it to the furnace 11 , and the combustion unit 1 . A heat transfer unit 4 that heats air, water supplied to the steam generation unit 2, and steam generated in the steam generation unit 2 by high-temperature exhaust gas from the combustion unit 1, and soot and dust in the exhaust gas from the heat transfer unit 4. A dust collector 5 for separating and collecting dust and a chimney 6 for releasing the exhaust gas cleaned by the dust collector 5 to the atmosphere are provided.

The combustion section 1 has a furnace 11 as a combustion chamber. The furnace 11 has a vertically elongated cylindrical shape, and has a tapered bottom to enable efficient combustion by increasing the density of solid fuels and fluid materials containing hydrogen-absorbing alloys. The bottom portion of the furnace 11 may not be tapered, and the furnace 11 may be formed in a cylindrical shape with a substantially constant cross-sectional shape from the top to the bottom. The area indicated by "A" at the bottom of the furnace 11 indicates a fluidized bed (also called fluidized bed or sand bed) formed by high-density fluidized material. In the fluidized bed A, a powdery, particulate, or massive fluidizing material such as silica sand or a hydrogen-absorbing alloy is fluidized by air as a fluidizing fluid supplied from the bottom of the furnace 11 . Solid fuel such as coal or biomass put into the fluidized bed A or hydrogen released from the hydrogen storage alloy put into the fluidized bed A is stirred in the fluidized bed A with a high temperature fluid material and It burns efficiently by repeated contact with air.

In addition, since the fluidized material rises in the furnace 11 due to the ascending air current generated by combustion, the fluidized material also exists in the free board B, which is the space above the fluidized bed A. The density of the fluidized material in the freeboard B is lower than the density of the fluidized material in the fluidized bed A, and decreases toward the top of the furnace 11 . In the freeboard B, the fuel that has not been completely burned in the fluidized bed A is burned while coming into contact with the floating fluidized material. Silica sand was exemplified as the fluidizing material, but any material may be used as long as it functions as a medium for transferring heat to the fuel while maintaining a solid state without burning even in the high-temperature furnace 11 and flowing. Sand, stones such as limestone, and ash may also be used. Since the hydrogen storage material such as the hydrogen storage alloy that supports hydrogen as fuel also functions as a fluid material, a sufficient amount of the hydrogen storage material for realizing the function of the fluidized bed A is supplied to the furnace 11. If so, it is not necessary to supply other fluid materials such as silica sand to the furnace 11 . As described above, with the hydrogen storage material such as the hydrogen storage alloy, the fuel (hydrogen) and fluid material (hydrogen storage material before and after hydrogen release) can be supplied to the furnace 11 at once.

At the bottom of the furnace 11, a perforated plate (also called a dispersion plate) 121 is provided as a fluid permeable part made of a porous material that allows fluid including air to pass through. The air box 122, which is a space directly below the perforated plate 121, supplies pressurized air supplied from the first blower 71 as a blower via the first flow control valve 71A into the furnace 11 via the perforated plate 121. It constitutes a flowing fluid supply section (air supply section). The pressurized air supplied to the bottom of the furnace 11 by the wind box 122 fluidizes the fluid material to form the fluidized bed A and is used to burn the fuel in the fluidized bed A or the freeboard B.

In addition, a carbon-free fluid fuel such as ammonia or hydrogen or a carbon-free fuel is supplied from the wind box 122 through the perforated plate 121 into the furnace 11 together with pressurized air, and is burned in the fluidized bed A or the freeboard B. You may let Replacing some or all of conventional carbon-containing fuels, such as coal, biomass, sludge, and waste wood, with non-carbon-containing fuels can reduce greenhouse gas emissions in combustion equipment such as CFB boilers. As will be described later, using a hydrogen storage material such as a hydrogen storage alloy as a solid fuel also leads to an alternative to conventional fuels with clean fuels that emit less greenhouse gases.

A second blower 72 provided in addition to the first blower 71 has a second flow rate of Pressurized air is supplied into the freeboard B through the control valve 72A. In FIG. 1, the perforated plate 121 is used as an example to describe the fluid permeable portion, but the fluid permeable portion may be anything as long as it can cause the fluid material to flow in the fluidized bed A. It may be formed from a number of plates with slits formed therein.

In order to circulate the fluidized material in the fluidized bed A, an external circulation mechanism 13 having a circulation path outside the furnace 11 is provided. The external circulation mechanism 13 includes an extraction tube 131 that communicates with the bottom of the furnace 11 and can extract a part of the fluidized material in the fluidized bed A, and controls the opening and closing of the extraction tube 131 to control the flow rate of the fluidized material, that is, the extraction tube. An on-off valve 132 capable of adjusting the amount of the fluidized material withdrawn by the extraction pipe 131, a fluidized material conveyor 133 such as a bucket conveyor that conveys upward the fluidized material extracted by the extraction pipe 131, and corresponding to the upper part of the fluidized bed A A fluid material silo 134 is provided on the outer periphery of the furnace 11 and receives the fluid material conveyed by the fluid material conveyer 133 , and a fluid material re-injection unit 135 reintroduces the fluid material stored in the fluid material silo 134 into the furnace 11 . Prepare.

The extraction pipe 131, the on-off valve 132, the fluid material conveyor 133, the fluid material silo 134, and the fluid material re-injection unit 135 constitute a fluid material circulation path that connects the bottom surface and the side surface of the furnace 11 outside the furnace 11. . That is, the fluid material extracted from the bottom surface of the furnace 11 by the extraction pipe 131 passes through the on-off valve 132, the fluid material conveyor 133, and the fluid material silo 134, and is discharged from the side surface of the furnace 11 by the fluid material re-injection unit 135. It is put into the fluidized bed A again. As will be described later, this circulation path is provided with a recovery section 17 for recovering a part or all of the hydrogen storage material such as a hydrogen storage alloy contained in the circulating fluid material.

The furnace wall, which is the side wall of the furnace 11, has a hydrogen storage material supply unit 14 that supplies a hydrogen storage material such as a hydrogen storage alloy into the furnace 11, and a fuel supply unit that supplies a fuel different from the hydrogen storage material into the furnace 11. 15 and a starting unit 16 for starting the CFB boiler. Although the illustration is omitted because the hydrogen storage material supply unit 14 supplies the hydrogen storage material that also functions as the fluid material, the fluid material supply unit that supplies other fluid materials such as silica sand into the furnace 11 is the hydrogen storage material. It may be provided in addition to the supply unit 14 . The hydrogen storage material supply unit 14 includes a funnel-shaped hopper 141 that stores the hydrogen storage material, a crushing unit 142 that crushes the hydrogen storage material discharged from the bottom of the hopper 141 into granules, and the hydrogen that has been crushed by the crushing unit 142. A feeder 143 is provided for feeding stock material into the furnace 11 .

The hydrogen storage material is a material capable of releasing stored hydrogen when heated, and is exemplified by a hydrogen storage alloy. Hydrogen Storage Alloy, Hydrogen Absorbing Alloy, Metal Hydride is an alloy that reacts with hydrogen to store or absorb hydrogen in the form of a metal hydride compound and releases hydrogen when heated. AB2 type (based on alloys of transition elements such as titanium, manganese, zirconium, nickel, etc.), AB5 type such as LaNi ₅ , ReNi ₅ (one rare earth element, niobium, zirconium, five nickel, alloys containing transition elements such as cobalt and aluminum), Ti-Fe (titanium-iron) type, V (vanadium) type, Mg (magnesium) type, Pd (palladium) type, Ca (calcium) type etc. are known.

Among these hydrogen storage alloys, the Ti-Fe type, which is available at a relatively low cost, needs to be placed in a high temperature environment of about 450 ° C in order to efficiently store or release hydrogen, and it is popular because of its complexity. was not progressing. On the other hand, in this embodiment, the furnace 11, which reaches a high temperature of about 900° C. during normal operation (in order to suppress the generation of harmful substances such as dioxin and carbon monoxide due to incomplete combustion, the freeboard B is also installed in the furnace 11). The hydrogen-absorbing alloy can be naturally heated by heating, and the hydrogen-absorbing alloy can be naturally heated. In this way, hydrogen storage alloys or hydrogen as carbon-free fuels replace some or all of the conventional carbon-containing fuels such as coal, biomass, sludge, waste wood, etc. with clean fuels with low greenhouse gas emissions. can.

In addition, when a sufficient amount of fuel (hydrogen) for combustion in the furnace 11 is supplied from the hydrogen storage material supply unit 14, a fuel supply unit 15 described later that supplies a fuel different from the hydrogen storage material into the furnace 11 is used. It does not have to be provided. Further, the hydrogen storage material is not limited to the hydrogen storage alloy, and any material that can release the stored hydrogen when heated may be used. For example, the organic macromolecules or organic polymers capable of storing hydrogen disclosed in WO2015/005280 may also be used as the hydrogen storage material in this embodiment.

The pulverizing unit 142 pulverizes the hydrogen storage material such as the hydrogen storage alloy into granules before being supplied to the furnace 11 . The size of the hydrogen storage alloy suitable for transportation to the CFB boiler or hopper 141 may differ from the size of the hydrogen storage alloy suitable for releasing hydrogen in the furnace 11 and functioning as a fluid material before and after releasing hydrogen. The pulverizing unit 142 pulverizes the hydrogen storage alloy into particles having a particle size suitable for the latter. If there is not much difference between the particle diameters suitable for the former and the latter, the pulverizing section 142 may not be provided. Here, the terms "particle", "granular", and "particle size" do not refer to specific sizes or dimensions, and if the hydrogen storage material supplied into the furnace 11 can release hydrogen as fuel, the size and dimensions can be changed. does not matter. For example, the terms "lump", "lump", and "lump diameter" used for relatively large particles, and the terms "powder", "powder", and "powder diameter" used for relatively small particles are used in the present embodiment. Included in "particle", "granular", and "particle size". A required amount of the granular hydrogen storage material pulverized by the pulverizing unit 142 is fed into the furnace 11 by a feeder 143 whose rotation speed is controllable.

The fuel supply unit 15 supplies a solid fuel different from the hydrogen storage material into the furnace 11. The fuel supply unit 15 includes a funnel-shaped hopper 151 that stores solid fuel, and a feeder 152 that supplies the solid fuel discharged from the bottom of the hopper 151 into the furnace 11 . By controlling the rotation speed of the feeder 152 , a required amount of solid fuel is introduced into the furnace 11 .

The solid fuel supplied into the furnace 11 by the fuel supply unit 15 is not particularly limited, but examples thereof include various types of coal such as anthracite, bituminous coal, lignite, biomass, sludge, and waste wood. In the CFB boiler, high combustion efficiency can be achieved by using the high-temperature fluid material that flows within the furnace 11 as a medium, so that even low-quality fuel and flame-retardant fuel can be efficiently burned. The solid fuel mentioned above is a carbon-containing fuel that contains carbon, but the fuel supply unit 15 may add or replace the solid fuel with fluid fuel or carbon-free fuel that does not contain carbon, such as ammonia or hydrogen. It may be supplied into the furnace 11 .

The starting unit 16 that starts the CFB boiler includes a starting fuel reservoir 161 , a starting fuel control valve 162 and a starting burner 163 . The starting fuel reservoir 161 stores heavy oil as carbon-containing fuel. The starting fuel control valve 162 controls the amount of heavy oil supplied from the starting fuel reservoir 161 to the starting burner 163 . Specifically, the starting fuel control valve 162 is opened when the CFB boiler is started, and supplies the heavy oil stored in the starting fuel reservoir 161 to the starting burner 163 . The starting burner 163 heats the fluidized material in the fluidized bed A with a flame generated by combustion of the heavy oil supplied from the starting fuel control valve 162 . Since the starting burner 163 is provided with a downward inclination, the surface of the fluidized bed A formed by the fluidized material is directly heated, and the temperature of the fluidized bed A and the inside of the furnace 11 is efficiently raised. Since the starting burner 163 heats the sand-like fluidized bed A from above in this way, it is also called a sand top burner.

After startup of the CFB boiler in which the fluidized bed A and the inside of the furnace 11 are sufficiently heated, specifically after hydrogen can be released and burned from the hydrogen storage material in the fluidized bed A (the above-mentioned Ti-Fe type After the fluidized bed A reaches a temperature sufficiently higher than about 450° C. required for hydrogen release in the case of the hydrogen storage alloy of (1), the starting fuel control valve 162 is closed and the heavy oil to the starting burner 163 is supplied. stop the supply. In the subsequent normal operating state, the hydrogen released by the hydrogen storage material supplied from the hydrogen storage material supply unit 14 and the fuel different from the hydrogen storage material supplied from the fuel supply unit 15 are burned in the high-temperature furnace 11. . After releasing hydrogen as fuel, the hydrogen storage material flows within the furnace 11 and functions as a fluid material that mediates the combustion of the fuel. It is recovered by a recovery unit 17 provided on the path.

The recovery unit 17 that recovers the hydrogen storage material from the bottom of the furnace 11 includes a separation unit 171 that separates and recovers excess hydrogen storage material from the fluid material circulating through the external circulation mechanism 13 . The separation unit 171 can separate substances having desired properties by using differences in mechanical or dynamic properties such as mass, density, particle size, shape, etc., and physical properties such as magnetism. For example, even if the fluid material circulating in the external circulation mechanism 13 contains a fluid material other than a hydrogen-absorbing alloy such as silica sand, or ash or soot generated by combustion in the furnace 11, hydrogen Only the storage alloy can be efficiently separated and recovered. In particular, in the case of a magnetic hydrogen storage alloy such as a Ti—Fe type, the magnetic separator 1711 can efficiently separate and recover only the magnetic hydrogen storage alloy by magnetism. In addition, even when the fluid material circulating in the external circulation mechanism 13 contains hydrogen storage alloys with different particle sizes, only the hydrogen storage alloys with a desired particle size range can be efficiently separated and recovered. . The hydrogen storage alloy separated and recovered after releasing hydrogen in this way is transported to a hydrogen filling facility (not shown) and refilled with hydrogen. Reused as fuel.

According to the above configuration, the CFB boiler can be efficiently operated by introducing the hydrogen storage material that functions as a hydrogen fuel source and fluid material into the furnace 11, and the existing carbon-containing fuel can be replaced with hydrogen fuel. Emission of effect gas can be reduced.

The combustion section 1 of the CFB boiler has been described in detail above. Next, the configuration of the CFB boiler other than the combustion section 1 will be described. The steam generating unit 2 includes a drum 21 that stores water for generating steam, a water supply pipe 22 that supplies water to the drum 21, a water pipe 23 that guides the water in the drum 21 into the high-temperature furnace 11 to heat it, A steam pipe 24 is provided for discharging steam generated from water heated in the water pipe 23 from the drum 21 as the output of the CFB boiler. The water supply pipe 22 meanders in the heat transfer section 4 through which the high-temperature exhaust gas of the combustion section 1 passes to form an economizer that preheats the water supply, and the steam pipe 24 is a heat transfer section through which the high-temperature exhaust gas of the combustion section 1 passes. A superheater that superheats steam is configured by meandering inside 4 . Similarly, the pressurized air supplied into the furnace 11 by the first blower 71 and the second blower 72 is also preheated by the high-temperature exhaust gas inside the heat transfer section 4 .

The fluidizing material circulation unit 3 includes a cyclone 31 that separates and collects the fluidizing material containing the granular hydrogen-absorbing alloy from the exhaust gas discharged from the upper part of the furnace 11 , and the fluidizing material collected by the cyclone 31 is passed through the furnace 11 . It has a seal pot 32 that returns to the The cyclone 31 is a cyclone-type powder separator having a generally cylindrical upper portion and a generally conical lower portion, and generates an air flow spirally descending along the inner wall. Fluid materials such as granular hydrogen-absorbing alloys contained in the exhaust gas from the furnace 11 are collected by coming into contact with the inner wall of the cyclone 31 and falling down while descending spirally along the airflow.

A seal pot 32 provided below the cyclone 31 is filled with a fluid material to prevent backflow of unburned gas from the furnace 11 to the cyclone 31. The fluid material such as granular hydrogen-absorbing alloy filled in the seal pot 32 is gradually returned into the furnace 11 in the form of being pushed out by the weight of the fluid material newly collected by the cyclone 31 .

FIG. 2 shows the overall configuration of a rotary kiln 100 as a combustion device. The rotary kiln 100 includes a rotary kiln 200 and a secondary combustion chamber 300 as combustion chambers, a communication chute (connecting portion) 400, and an electric furnace 600 as a recovery portion. The rotary kiln 100 is a combustion apparatus that separates a metal-containing workpiece W into slag and metal by means of a rotary furnace 200 or an electric furnace 600 and recovers the metal. The objects to be processed W containing metal are, for example, substrates of electronic devices, electric wire scraps, and copper, gold and silver slag. The rotary kiln 100 can recover metals such as Cu (copper), Au (gold), Ag (silver), Pb (lead), Sn (tin), and Pd (palladium) from these workpieces W to be processed. As will be described later, when a hydrogen storage alloy (hydrogen storage material H) as a hydrogen fuel source is put into the rotary kiln 100 in addition to the workpiece W, the hydrogen storage alloy can be separated and recovered together with the metal.

A rotary furnace 200 that burns and melts the object W to be processed is formed in a cylindrical shape, and the inner wall is lined with a refractory material. The workpiece W charged into the rotary furnace 200 is burned or melted at about 1400-1500° C. by hot air from the burner 10 . Fuel oil is supplied to the burner 10 together with air from the fuel supply unit. In this embodiment, hydrogen released from the hydrogen storage material H introduced into the rotary furnace 200 together with the workpiece W can also be used as fuel. , the amount of fuel oil that generates greenhouse gases can be reduced.

The rotary furnace 200 during combustion treatment is rotationally driven around a cylindrical shaft, and while stirring the object W to be treated and the hydrogen storage material H inside, hydrogen released from the hydrogen storage material H stirs the object W to be treated. Burn efficiently. Since the rotating shaft of the rotary furnace 200 is inclined downward, the material to be processed W flows from the high-side inlet 2a to the low-side outlet 2b together with the hydrogen storage material H while being burned. On the side of the inlet 2a of the rotary furnace 200, there is a charging chute 7 for charging the workpiece W and the hydrogen storage material H, and a loading chute 7 for pushing the charged workpiece W and the hydrogen storage material H into the rotary furnace 200. A pusher 8 is provided.

Within the rotary furnace 200, the burned material W to be processed and the melted hydrogen storage material H (hydrogen storage alloy) are separated into slag S and metal M1 due to the difference in specific gravity. In addition, combustible substances in the object to be processed W are thermally decomposed into gas. The metal M1 (including the hydrogen storage alloy) separated from the object to be processed W and the hydrogen storage material H is in a molten or semi-molten state and accumulates on the lower layer side. be. The peripheral wall 2c forming the bottom (lower part in FIG. 2) of the cylindrical rotary furnace 200 whose axial direction is substantially horizontal is covered with the molten metal M1 (including the hydrogen storage alloy) accumulated at the bottom of the rotary furnace 200. A tapping nozzle (exhaust port) 9 is provided as a collecting portion capable of downwardly discharging the .

The tapping nozzle 9 is kept closed while the rotary furnace 200 rotates and burns or melts the workpiece W and the hydrogen storage material H. By opening the tapping nozzle 9 after the workpiece W and the hydrogen storage material H are completely burned or melted and the rotary furnace 200 stops rotating, The accumulated metal M1 can be separated and recovered from the tapping nozzle 9. - 特許庁The metal M1 and slag S that have not been separated and recovered by the tapping nozzle 9 are thrown into the electric furnace 600 from the bottom of the secondary combustion chamber 300 .

The secondary combustion chamber 300 connected to the outlet 2b at the right end of the rotary furnace 200 further burns the gas generated in the rotary furnace 200 to decompose dioxins and malodorous substances and supply them to the exhaust gas treatment equipment. In the secondary combustion chamber 300, a burner 110 for secondary combustion is provided near the outlet 2b of the rotary furnace 200, and a supply unit and a stirring blower for supplying urea, air, and SCC temperature-controlled water are provided above the burner 110. Fuel oil is supplied to the burner 110 together with air from a fuel supply unit. Since the fuel and gas can be effectively burned, the amount of fuel oil used in the burner 110 for secondary combustion can be reduced.

A communication chute 400 extending downward from the connection between the rotary furnace 200 and the secondary combustion chamber 300 is a communication passage that connects the rotary furnace 200 and the electric furnace 600 . The wall of the communication chute 400 is provided at a position where the slag S discharged from the outlet 2b of the rotary furnace 200 does not contact. Therefore, the slag S discharged from the outlet 2b of the rotary furnace 200 drops without coming into contact with the wall of the connecting chute 400 and is thrown into the electric furnace 600. As shown in FIG. On the other hand, an emergency burner 120 is provided to melt the slag S in case it adheres to the walls of the connecting chute 400 .

The electric furnace 600 is connected to the rotary furnace 200 via a communication chute 400, and heats the metal containing the hydrogen storage alloy from the melted material W and the hydrogen storage material H put into the rotary furnace 200 by electrical heat treatment. separate. Specifically, the electric furnace 600 can recover the metal containing the hydrogen-absorbing alloy remaining in the slag S separated in the rotary furnace 200 . An electric furnace 600 configured as an electric resistance heating furnace includes a tank 20 in which a molten material is retained to separate a metal M2 containing a hydrogen-absorbing alloy from the slag S, and

electrodes

21A, 21B, and 21C for electrically heating the slag S. Prepare. In the bath 20 heated by the

electrodes

21A, 21B, 21C, a layer of metal M2 containing a molten hydrogen-absorbing alloy is formed on the lower side and a layer of molten slag S is formed on the upper side.

The electric furnace 600 is provided with a coke supply device 22A, which supplies coke as a reducing agent into the tank 20 through a supply line 22B. The slag S that has undergone combustion treatment, that is, oxidation treatment, in the rotary furnace 200 contains metal oxides, but the metal oxides can be recovered by being reduced to metal M2 by the reducing action of coke. In addition to coke, coal, waste carbon, or the like may be used as the reducing agent. By maintaining the bath 20 of the electric furnace 600 as described above at about 1400-1500° C. similar to that of the rotary furnace 200 by means of the

electrodes

21A, 21B, and 21C, the slag S is retained for about 3-6 hours. Almost all metal components can be recovered as metal M2 (including hydrogen storage alloy). Specifically, the metal M2 containing the hydrogen-absorbing alloy is discharged from the metal recovery line 230 connected to the lower part of the tank 20, and the slag S not containing the metal M2 is discharged from the slag recovery line 240 connected to the upper part of the tank 20. Ejected.

According to the above configuration, by putting the hydrogen storage material H functioning as a hydrogen fuel source into the rotary kiln 200, the combustion efficiency in the rotary kiln 100 can be improved, and the existing fuel oil as a carbon-containing fuel can be replaced with hydrogen fuel. This can reduce greenhouse gas emissions. Moreover, when the hydrogen storage material H is a hydrogen storage alloy, the hydrogen storage alloy can be efficiently recovered together with the metals M1 and M2 by the tapping nozzle 9 and the electric furnace 600 as the recovery unit.

The present invention has been described above based on the embodiments. It should be understood by those skilled in the art that the embodiments are examples, and that various modifications can be made to combinations of each component and each treatment process, and such modifications are also within the scope of the present invention.

Although a CFB boiler was explained as an example of a boiler in FIG. 1, the present invention can also be applied to a BFB boiler (a bubbling fluidized bed boiler). The configuration of the BFB boiler is the same as that of the CFB boiler except that it does not include the fluid material circulation unit 3 that collects the fluid material that has flowed out of the furnace 11 and returns it to the inside of the furnace 11 .

Note that the functional configuration of each device described in the embodiments can be realized by hardware resources or software resources, or by cooperation between hardware resources and software resources. Processors, ROMs, RAMs, and other LSIs can be used as hardware resources. Programs such as operating systems and applications can be used as software resources.

The present invention relates to a combustion device that generates combustion.

1 Combustion section 3 Fluid material circulation section 9 Tapping nozzle 10 Burner 11 Furnace 14 Hydrogen storage material supply section 15 Fuel supply section 17 Recovery section 31 Cyclone 100 Rotary kiln 110 Burner 120 Burner 142 Crushing section, 171 separation section, 200 rotary furnace, 300 secondary combustion chamber, 600 electric furnace, 1711 magnetic separation section.

Claims

a combustion chamber for generating combustion;
a hydrogen storage material supply unit that supplies a hydrogen storage material capable of releasing stored hydrogen when heated to the combustion chamber;
A combustion device comprising a
The combustion device according to claim 1, wherein the hydrogen storage material is a hydrogen storage alloy.
The combustion device according to claim 1 or 2, wherein the hydrogen storage material is granular.
The combustion apparatus according to claim 3, further comprising a pulverizing section for pulverizing the hydrogen storage material into granules before being supplied to the combustion chamber.
The combustion apparatus according to claim 3, further comprising a circulation unit that collects the granular hydrogen storage material coming out of the combustion chamber and returns it to the combustion chamber.
The combustion device according to claim 1 or 2, further comprising a recovery unit that recovers the hydrogen storage material from the bottom of the combustion chamber.
The combustion apparatus according to claim 6, wherein when the hydrogen storage material has magnetism, the recovery unit further includes a magnetic separation unit that separates the hydrogen storage material by magnetism.
The combustion apparatus according to claim 1 or 2, further comprising a fuel supply section for supplying a fuel different from the hydrogen storage material to the combustion chamber.
The combustion apparatus according to claim 1 or 2, wherein the combustion apparatus is at least one of a circulating fluidized bed boiler, a bubbling fluidized bed boiler, and a rotary kiln.
a hydrogen storage material supply step of supplying a hydrogen storage material capable of releasing stored hydrogen when heated to the combustion chamber;
a combustion step of burning hydrogen released from the hydrogen storage material in the combustion chamber;
Combustion method comprising: