Combustion device and combustion method

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

[Technical Field]

[0001] The present invention relates to a combustion device for generating combustion. [Background technology]

[0002] As a combustion device that generates combustion, there are a number of types of combustion equipment, including a bubbling fluidized bed (BFB), which burns fuel using a fluidized bed or a fluidized bed formed by fluidizing materials such as silica sand in a combustion chamber. Fluidized Bed (CFB) boilers and Circulating Fluidized Bed (CFB) boilers Patent Document 1 discloses a CFB boiler. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-255612 Summary of the Invention [Problem to be solved by the invention]

[0004] BFB boilers and CFB boilers can achieve high combustion efficiency by using a high-temperature fluid material that flows inside the combustion chamber, making them suitable for burning fuels of unstable quality or low-flammability, such as biomass (biofuel), sludge, and waste materials (waste paper, waste plastic, waste tires, etc.).However, because all of these fuels are primarily carbon-based, they generate greenhouse gases such as carbon dioxide when burned, which could further exacerbate global warming.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a combustion device that can reduce the generation of greenhouse gases. [Means for solving the problem]

[0006] In order to solve the above problems, a combustion device according to one aspect of the present invention includes a combustion chamber that generates combustion, and a hydrogen storage material supply unit that supplies the combustion chamber with a hydrogen storage material that can release stored hydrogen when heated. When the hydrogen released from the hydrogen storage material is combusted in the combustion chamber, the main product produced is water, thereby reducing the generation of greenhouse gases.

[0007] Another aspect of the present invention is a combustion method, which 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 combusting the hydrogen released from the hydrogen storage material in the combustion chamber.

[0008] Any combination of the above components, and any transformation of the present invention into a method, device, system, recording medium, computer program, etc., are also valid aspects of the present invention. [Effects of the Invention]

[0009] According to the present invention, the generation of greenhouse gases in a combustion device can be reduced. [Brief explanation of the drawings]

[0010] [Figure 1] The overall configuration of a circulating fluidized bed boiler is shown. [Figure 2] The overall configuration of a rotary kiln is shown. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description and drawings, identical or equivalent components, parts, and processes are designated by the same reference numerals, and redundant explanations will be omitted as appropriate. The scale and shape of each part shown in the drawings are set for convenience to facilitate explanation, and should not be interpreted as limiting unless otherwise specified. The embodiments are merely examples and do not limit the scope of the present invention in any way. Individual features and their combinations described in the embodiments are not necessarily essential to the invention.

[0012] The combustion device of the present invention is any device that generates combustion. For example, when the combustion device is configured as a boiler, the combustion device can be configured as a BFB boiler or CFB boiler that burns fuel containing hydrogen released from a hydrogen storage material using a fluidized bed or fluidized bed formed by a fluidizing material such as silica sand or a granular hydrogen storage material described below that flows in a combustion chamber. 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.

[0013] Figure 1 shows the overall configuration of a CFB boiler (circulating fluidized bed boiler) as a combustion device. The CFB boiler is equipped with a combustion section 1, which supplies fuel containing hydrogen released from a hydrogen storage alloy to a furnace 11 where a fluid material such as silica sand or granular hydrogen storage alloy flows, and burns the fuel; a steam generation section 2, which generates steam from water using the heat generated in the combustion section 1; a fluid material circulation section 3, which serves as a circulation section that collects the fluid material that leaves the furnace 11 and returns it to the furnace 11; a heat transfer section 4, which heats the air supplied to the combustion section 1, the water supplied to the steam generation section 2, and the steam generated in the steam generation section 2 with the high-temperature exhaust gas from the combustion section 1; a dust collector 5, which separates and collects soot and dust in the exhaust gas from the heat transfer section 4; and a chimney 6, which releases the exhaust gas purified by the dust collector 5 into the atmosphere.

[0014] The combustion section 1 includes a furnace 11 as a combustion chamber. The furnace 11 is a vertically elongated cylinder with a tapered bottom to increase the density of the solid fuel and fluidized material containing the hydrogen storage alloy, enabling efficient combustion. The bottom of the furnace 11 does not have to be tapered; the furnace 11 may be cylindrical with a substantially constant cross-sectional shape from top to bottom. The area marked "A" at the bottom of the furnace 11 is a fluidized bed (also called a fluidized bed or sand layer) formed by a high-density fluidized material. In the fluidized bed A, powdered, granular, or lumpy fluidized material such as silica sand or a hydrogen storage alloy is fluidized by air supplied from the bottom of the furnace 11 as a fluidizing fluid. Solid fuel such as coal or biomass introduced into the fluidized bed A, or hydrogen released from the hydrogen storage alloy introduced into the fluidized bed A, is repeatedly agitated within the fluidized bed A and repeatedly comes into contact with the high-temperature fluidized material and air, resulting in efficient combustion.

[0015] Note that because the fluidized material rises within the furnace 11 due to the updraft generated by combustion, fluidized material also exists in the freeboard B, which is the space above the fluidized bed A. The density of the fluidized material in the freeboard B is lower than that in the fluidized bed A and decreases the higher in the furnace 11. In the freeboard B, fuel that was not completely combusted in the fluidized bed A comes into contact with the floating fluidized material and is burned. Note that although silica sand is exemplified as the fluidized material, any material may be used as long as it remains solid and fluidizes without being combusted even in the high-temperature furnace 11 and functions as a medium for transferring heat to the fuel. For example, other types of sand, stone such as limestone, or ash may also be used. Note that hydrogen storage materials such as hydrogen storage alloys, which are carriers of hydrogen as fuel, also function as fluidized materials. Therefore, if a sufficient amount of hydrogen storage material is supplied to the furnace 11 to realize the function of the fluidized bed A, other fluidized materials such as silica sand do not need to be supplied to the furnace 11. In this way, by using a hydrogen storage material such as a hydrogen absorbing alloy, the fuel (hydrogen) and the fluid material (hydrogen storage material before and after hydrogen release) can be supplied to the furnace 11 all at once.

[0016] A perforated plate (also called a dispersion plate) 121, which serves as a fluid permeable section and is made of a porous material that allows fluids including air to pass through, is provided at the bottom of the furnace 11. An air box 122, which is the space directly below the perforated plate 121, constitutes a fluid fluid supply section (air supply section) that supplies pressurized air, supplied from the first blower 71 as an air blower via the first flow control valve 71A, into the furnace 11 via the perforated plate 121. The pressurized air supplied to the bottom of the furnace 11 by the air box 122 fluidizes the fluid material to form fluidized bed A, and is also used for burning fuel in fluidized bed A or the freeboard B.

[0017] Alternatively, a carbon-free fluid fuel or carbon-free fuel such as ammonia or hydrogen may be supplied into the furnace 11 together with pressurized air from the wind box 122 through the perforated plate 121 and combusted in the fluidized bed A or freeboard B. Replacing part or all of the conventional carbon-containing fuels such as coal, biomass, sludge, and waste wood with carbon-free fuels can reduce the generation of greenhouse gases in combustion equipment such as CFB boilers. As will be described later, using hydrogen storage materials such as hydrogen storage alloys as solid fuels can also lead to the replacement of conventional fuels with clean fuels that emit fewer greenhouse gases.

[0018] The second blower 72, which is provided in addition to the first blower 71, supplies pressurized air into the freeboard B via a second flow control valve 72A in order to promote combustion of fuel in the freeboard B and suppress the generation of harmful substances such as dioxins and carbon monoxide due to incomplete combustion. Although the fluid permeation portion has been described using the perforated plate 121 as an example in Fig. 1, the fluid permeation portion may be any portion that can fluidize the fluidized material in the fluidized bed A, and may be formed, for example, from a number of plates formed with slits that supply the fluidized fluid into the furnace 11.

[0019] 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 pipe 131 that communicates with the bottom of the furnace 11 and is capable of extracting a portion of the fluidized material in the fluidized bed A, an on-off valve 132 that controls the opening and closing of the extraction pipe 131 to adjust the flow rate of the fluidized material, i.e., the amount of fluidized material extracted by the extraction pipe 131, a fluidized material conveyor 133 such as a bucket conveyor that transports the fluidized material extracted by the extraction pipe 131 upward, a fluidized material silo 134 that is provided on the outer periphery of the furnace 11 corresponding to the upper part of the fluidized bed A and receives the fluidized material transported by the fluidized material conveyor 133, and a fluidized material re-introduction section 135 that re-introduces the fluidized material stored in the fluidized material silo 134 into the furnace 11.

[0020] The withdrawal pipe 131, on-off valve 132, fluidized material conveyor 133, fluidized material silo 134, and fluidized material re-introduction section 135 constitute a fluidized material circulation path that connects the bottom and side of furnace 11 outside of furnace 11. That is, the fluidized material withdrawn from the bottom of furnace 11 by withdrawal pipe 131 passes through on-off valve 132, fluidized material conveyor 133, and fluidized material silo 134, and is re-introduced into fluidized bed A from the side of furnace 11 by fluidized material re-introduction section 135. As will be described later, this circulation path is provided with a recovery section 17 for recovering some or all of the hydrogen storage material, such as a hydrogen storage alloy, contained in the circulating fluidized material.

[0021] The furnace wall, which is the side wall of the furnace 11, is provided with a hydrogen storage material supply unit 14 that supplies a hydrogen storage material such as a hydrogen absorbing alloy into the furnace 11, a fuel supply unit 15 that supplies a fuel different from the hydrogen storage material into the furnace 11, and a startup unit 16 that starts up the CFB boiler. Note that although not shown in the figure, a fluidized material supply unit that supplies another fluidized material such as silica sand into the furnace 11 may be provided in addition to the hydrogen storage material supply unit 14, because the hydrogen storage material supply unit 14 supplies the hydrogen storage material that also functions as a fluidized material. 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 a feeder 143 that supplies the hydrogen storage material crushed in the crushing unit 142 into the furnace 11.

[0022] Hydrogen storage materials are materials that can release stored hydrogen when heated, and examples include hydrogen storage alloys. Hydrogen storage alloys (Hydrogen Absorbing Alloys, Metal Hydride) react with hydrogen to store or absorb hydrogen in the form of metal hydrides, and when heated, they convert it into water. It is an alloy with the property of releasing elements, and is of the AB2 type (titanium, manganese, zirconium, nickel). AB5 type (based on alloys of transition elements such as Kel), LaNi5, ReNi5, etc. (Based on alloys containing five transition elements such as nickel, cobalt, and aluminum in addition to silicon, niobium, and zirconium), Ti-Fe (titanium-iron) type, V (vanadium) type, Mg (magnesium Known types include magnesium type, palladium type, and calcium type.

[0023] Among these hydrogen storage alloys, the Ti-Fe type, which is relatively inexpensive and available, can efficiently absorb hydrogen. It is necessary to place it in a high temperature environment of about 450°C in order to store or release it, and due to this cumbersome process it has not become widespread. In contrast, in this embodiment, the temperature reaches a high temperature of approximately 900°C during normal operation. Furnace 11 (in order to prevent the generation of harmful substances such as dioxins and carbon monoxide due to incomplete combustion, the temperature inside furnace 11, including freeboard B, is generally maintained at approximately 800°C or higher) Since the hydrogen storage alloy can be heated naturally by the combustion, the release and combustion of hydrogen as fuel can be achieved simultaneously in the furnace 11. In this way, the hydrogen storage alloy or hydrogen as a carbon-free fuel can be used to replace part or all of conventional carbon-containing fuels such as coal, biomass, sludge, and waste wood with clean fuels that emit less greenhouse gases.

[0024] Note that if a sufficient amount of fuel (hydrogen) for combustion in the furnace 11 is supplied from the hydrogen storage material supply unit 14, it is not necessary to provide a fuel supply unit 15 (described below) that supplies a fuel other than the hydrogen storage material into the furnace 11. Furthermore, the hydrogen storage material is not limited to a hydrogen storage alloy, and any material that can release stored hydrogen when heated may be used. For example, the organic polymers or polymers capable of storing hydrogen disclosed in International Publication No. 2015 / 005280 may also be used as the hydrogen storage material in this embodiment.

[0025] The crushing unit 142 crushes the hydrogen storage material, such as a hydrogen storage alloy, into granules before it is 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 or for functioning as a fluid material before and after hydrogen release. The crushing unit 142 crushes the hydrogen storage alloy into particles of a size suitable for the latter. Note that if there is no significant difference between the particle sizes suitable for the former and latter, the crushing unit 142 may not be provided. Here, the terms "particle," "granular," and "particle size" do not refer to a specific size or dimension. The size and dimension of the hydrogen storage material supplied to the furnace 11 are not important as long as it can release hydrogen as fuel. For example, the terms "lump," "lump-like," and "lump diameter" used for relatively large particles and the terms "powder," "powder-like," and "powder diameter" used for relatively small particles are all included in the terms "particle," "granular," and "particle size" in this embodiment. The granular hydrogen storage material pulverized in the pulverizing section 142 is fed into the furnace 11 in a required amount by a feeder 143 whose rotation speed can be controlled.

[0026] The fuel supply unit 15 supplies 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 the solid fuel, and a feeder 152 that supplies the solid fuel discharged from the bottom of the hopper 151 into the furnace 11. The required amount of solid fuel is fed into the furnace 11 by controlling the rotation speed of the feeder 152.

[0027] The solid fuel supplied by the fuel supply unit 15 into the furnace 11 is not particularly limited, and examples thereof include various types of coal, such as anthracite, bituminous coal, and lignite, as well as biomass, sludge, and waste materials. In a CFB boiler, high combustion efficiency is achieved by using a high-temperature fluid material flowing within the furnace 11 as a medium, so that low-quality fuels and non-flammable fuels can also be efficiently burned. Note that the solid fuels listed above are carbon-containing fuels, but the fuel supply unit 15 may supply a fluid fuel that does not contain carbon, such as ammonia or hydrogen, or a carbon-free fuel into the furnace 11 in addition to or instead of the solid fuel.

[0028] The startup unit 16, which starts up the CFB boiler, includes a startup fuel storage unit 161, a startup fuel control valve 162, and a startup burner 163. The startup fuel storage unit 161 stores heavy oil as a carbon-containing fuel. The startup fuel control valve 162 controls the amount of heavy oil supplied from the startup fuel storage unit 161 to the startup burner 163. Specifically, the startup fuel control valve 162 opens when the CFB boiler is started up, and supplies the heavy oil stored in the startup fuel storage unit 161 to the startup burner 163. The startup burner 163 heats the fluidized material in the fluidized bed A with a flame generated by the combustion of the heavy oil supplied from the startup fuel control valve 162. Because the startup burner 163 is installed at an angle downward, 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. In this way, the startup burner 163 heats the sandy fluidized bed A from above, and is therefore also called an above-sand burner.

[0029] After the start of the CFB boiler when the fluidized bed A and the furnace 11 are sufficiently heated, specifically after the release and combustion of hydrogen from the hydrogen storage material in the fluidized bed A becomes possible (the aforementioned Ti-Fe type In the case of the hydrogen storage alloy, the fluidized bed A reaches a temperature that is sufficiently higher than the approximately 450°C required for hydrogen release. After the start-up fuel control valve 162 is turned off, the start-up fuel control valve 162 is closed, stopping the supply of heavy oil to the start-up burner 163. In the subsequent normal operating state, hydrogen released from the hydrogen storage material supplied from the hydrogen storage material supply unit 14 and a fuel different from the hydrogen storage material supplied from the fuel supply unit 15 are combusted in the high-temperature furnace 11. After releasing the hydrogen as fuel, the hydrogen storage material flows in the furnace 11 and functions as a fluid material that mediates the combustion of the fuel, but any hydrogen storage material in excess of the required amount is recovered in the recovery unit 17 provided in the circulation path of the fluid material in the external circulation mechanism 13.

[0030] The recovery unit 17, which recovers the hydrogen storage material from the bottom of the furnace 11, is equipped with a separation unit 171 that separates and recovers excess hydrogen storage material from the fluid material circulating in the external circulation mechanism 13. The separation unit 171 can separate materials with desired properties by utilizing differences in mechanical or dynamic properties such as mass, density, particle size, shape, and other physical properties, such as magnetism. For example, even if the fluid material circulating in the external circulation mechanism 13 contains fluid materials other than hydrogen storage alloys, such as silica sand, or ash and soot generated by combustion in the furnace 11, it is possible to efficiently separate and recover only the hydrogen storage alloy. In particular, in the case of magnetic hydrogen storage alloys such as Ti-Fe type, the magnetic separation unit 1711 can separate the magnetically demagnetized materials. Only the hydrogen storage alloys that have a desired particle size range can be efficiently separated and recovered. Furthermore, even if the fluid material circulating through the external circulation mechanism 13 contains hydrogen storage alloys with different particle sizes, only the hydrogen storage alloys that have a desired particle size range can be efficiently separated and recovered. The hydrogen storage alloys that have been separated and recovered in this way and have released hydrogen are transported to a hydrogen filling facility (not shown) and refilled with hydrogen, and then re-introduced into the hopper 141 of the hydrogen storage material supply unit 14 and reused as hydrogen fuel.

[0031] According to the above configuration, by introducing a hydrogen storage material that functions as a hydrogen fuel source and a fluidizing material into the furnace 11, the CFB boiler can be operated efficiently, and by replacing existing carbon-containing fuels with hydrogen fuel, greenhouse gas emissions can be reduced.

[0032] 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 generation section 2 includes a drum 21 that stores water for generating steam, a water feed 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, and a steam pipe 24 that discharges steam generated from the water heated in the water pipe 23 from the drum 21 as the output of the CFB boiler. The water feed pipe 22 snakes through the heat transfer section 4 through which the high-temperature exhaust gas from the combustion section 1 passes, thereby forming an economizer that preheats the feed water. The steam pipe 24 snakes through the heat transfer section 4 through which the high-temperature exhaust gas from the combustion section 1 passes, thereby forming a superheater that superheats the steam. Similarly, the pressurized air supplied to the furnace 11 by the first blower 71 and the second blower 72 is preheated by the high-temperature exhaust gas from the heat transfer section 4.

[0033] The fluidized material circulation section 3 includes a cyclone 31 that separates and collects fluidized material, including granular hydrogen storage alloys, from the exhaust gas discharged from the top of the furnace 11, and a seal pot 32 that returns the fluidized material collected by the cyclone 31 to the furnace 11. The cyclone 31 is a cyclone-type powder separator with a generally cylindrical upper portion and a generally conical lower portion, and generates an airflow that descends in a spiral shape along its inner wall. The fluidized material, such as granular hydrogen storage alloys, contained in the exhaust gas from the furnace 11 comes into contact with the inner wall of the cyclone 31 as it descends in a spiral shape along the airflow, and is collected when it falls.

[0034] The seal pot 32 provided below the cyclone 31 is filled with a fluidizing material to prevent backflow of unburned gas and the like from the furnace 11 to the cyclone 31. The fluidizing material, such as granular hydrogen storage alloy, filled in the seal pot 32 is gradually returned to the furnace 11 by being pushed out by the weight of the fluidizing material newly collected by the cyclone 31.

[0035] FIG. 2 shows the overall configuration of a rotary kiln 100 as a combustion device. The rotary kiln 100 includes a rotary furnace 200 and a secondary combustion chamber 300 as combustion chambers, a connecting chute (connector) 400, and an electric furnace 600 as a recovery unit. The rotary kiln 100 is a combustion device that separates a metal-containing workpiece W into slag and metal using the rotary furnace 200 and the electric furnace 600 and recovers the metal. Examples of the metal-containing workpiece W include substrates for electronic devices, scrap electric wire, 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 the workpiece W. Furthermore, as described below, when a hydrogen storage alloy (hydrogen storage material H) serving as a hydrogen fuel source is added to the rotary kiln 100 in addition to the workpiece W, the hydrogen storage alloy can also be separated and recovered along with the metals.

[0036] The rotary furnace 200, which burns and melts the workpiece W, is formed in a cylindrical shape and its inner wall is lined with a refractory material. The workpiece W is put into the rotary furnace 200 and is burned or melted at about 1400-1500°C by hot air from the burner 10. The burner 10 is supplied with air and fuel from a fuel supply section. Fuel oil is supplied, but in this embodiment, hydrogen released from the hydrogen storage material H that is fed into the rotary furnace 200 together with the workpiece W can also be used as fuel, thereby reducing the amount of fuel oil used that generates greenhouse gases.

[0037] During combustion treatment, the rotary furnace 200 is rotated around its cylindrical axis, stirring the workpiece W and hydrogen storage material H inside while efficiently combusting the workpiece W using hydrogen released from the hydrogen storage material H. Because the rotation axis of the rotary furnace 200 is tilted downward, the workpiece W flows together with the hydrogen storage material H from the inlet 2a on the higher side to the outlet 2b on the lower side while being combusted. On the inlet 2a side of the rotary furnace 200, there are provided an input chute 7 for inputting the workpiece W and hydrogen storage material H, and an input pusher 8 for pushing the input workpiece W and hydrogen storage material H into the rotary furnace 200.

[0038] Within the rotary furnace 200, the molten material of the burned workpiece W and hydrogen storage material H (hydrogen storage alloy) is separated into slag S and metal M1 due to the difference in specific gravity. Furthermore, combustible materials in the workpiece W are thermally decomposed into gas. The metal M1 (including the hydrogen storage alloy) separated from the workpiece W and hydrogen storage material H accumulates in a molten or semi-molten state at the bottom, where its surface is covered with slag S, preventing oxidation. A tapping nozzle (discharge port) 9 is provided on the peripheral wall 2c that forms the bottom (lower part in FIG. 2 ) of the cylindrical rotary furnace 200, whose axial direction is approximately horizontal, and serves as a recovery section that can discharge the molten metal M1 (including the hydrogen storage alloy) that has accumulated at the bottom of the rotary furnace 200 downward.

[0039] The tapping nozzle 9 is maintained in a closed state while the rotary furnace 200 is rotating and combusting or melting the workpiece W and the hydrogen storage material H. By opening the tapping nozzle 9 after the combustion or melting of the workpiece W and the hydrogen storage material H is completed and the rotation of the rotary furnace 200 has stopped, the metal M1 that has accumulated below the slag S at the bottom of the rotary furnace 200 can be separated and recovered from the tapping nozzle 9. Note that the metal M1 and slag S that could not be completely separated and recovered by the tapping nozzle 9 are fed into the electric furnace 600 from the bottom of the secondary combustion chamber 300.

[0040] The secondary combustion chamber 300, connected to the outlet 2b at the right end of the rotary furnace 200, further combusts the gas generated in the rotary furnace 200, decomposing dioxins, malodorous substances, and the like, and supplies the resulting gas to an exhaust gas treatment facility. A secondary combustion burner 110 is provided in the secondary combustion chamber 300 near the outlet 2b of the rotary furnace 200, and above it are provided a supply unit for supplying urea, air, and SCC temperature-controlled water, as well as an agitation blower. Fuel oil is supplied to the burner 110 from the fuel supply unit along with air, but in this embodiment, hydrogen released from the hydrogen storage material H introduced into the rotary furnace 200 can be used to effectively combust the workpiece W and gas within the rotary furnace 200, thereby reducing the amount of fuel oil used by the secondary combustion burner 110.

[0041] The connecting chute 400, which extends downward from the connection between the rotary furnace 200 and the secondary combustion chamber 300, is a connecting passage that connects the rotary furnace 200 and the electric furnace 600. The walls of the connecting chute 400 are positioned so that they do not come into contact with the slag S discharged from the outlet 2b of the rotary furnace 200. Therefore, the slag S discharged from the outlet 2b of the rotary furnace 200 falls without coming into contact with the walls of the connecting chute 400 and is thrown into the electric furnace 600. On the other hand, in case the slag S adheres to the walls of the connecting chute 400, an emergency burner 120 is provided to melt it.

[0042] The electric furnace 600 is connected to the rotary furnace 200 via the connecting chute 400, and separates metals containing hydrogen storage alloys from the molten material W and hydrogen storage material H introduced into the rotary furnace 200 by electrical heating. Specifically, the metals containing hydrogen storage alloys remaining in the slag S separated in the rotary furnace 200 can be recovered in the electric furnace 600. The electric furnace 600, configured as an electric resistance heating furnace, includes a tank 20 that stores the molten material and separates the metal M2 containing hydrogen storage alloys from the slag S, and electrodes 21A, 21B, and 21C that electrically heat the slag S. In the tank 20 heated by the electrodes 21A, 21B, and 21C, a layer of molten metal M2 containing hydrogen storage alloys is formed on the lower side, and a layer of molten slag S is formed on the upper side.

[0043] The electric furnace 600 is equipped with a coke supply device 22A, which supplies coke as a reducing agent into the vessel 20 via a supply line 22B. After undergoing the combustion process (i.e., oxidation process) in the rotary furnace 200, the slag S contains metal oxides. The reduction action of the coke reduces the metal oxides to metal M2, which can then be recovered. In addition to coke, coal, waste carbon, and other reducing agents may also be used. By maintaining the vessel 20 of the electric furnace 600 at approximately 1400–1500°C, the same temperature as the rotary furnace 200, using electrodes 21A, 21B, and 21C and retaining the slag S for approximately 3–6 hours, almost all of the metal components in the slag S can be recovered as metal M2 (including hydrogen-storage alloys). Specifically, metal M2 containing hydrogen-storage alloys is discharged from a metal recovery line 230 connected to the bottom of the vessel 20, and slag S not containing metal M2 is discharged from a slag recovery line 240 connected to the top of the vessel 20.

[0044] According to the above configuration, by charging the hydrogen storage material H, which functions as a hydrogen fuel source, into the rotary kiln 200, it is possible to improve the combustion efficiency in the rotary kiln 100, and by replacing fuel oil, which is an existing carbon-containing fuel, with hydrogen fuel, it is possible to reduce greenhouse gas emissions. Furthermore, 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, which serve as the recovery unit.

[0045] The present invention has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of the respective components and treatment processes, and that such modifications are also within the scope of the present invention.

[0046] 1, a CFB boiler has been described as an example of a boiler, but the present invention can also be applied to a BFB boiler (bubbling fluidized bed boiler). The configuration of a BFB boiler is similar to that of a CFB boiler, except that it does not have a fluid material circulation unit 3 that collects the fluid material that has left the furnace 11 and returns it to the furnace 11.

[0047] The functional configuration of each device described in the embodiments can be realized by hardware resources, software resources, or a combination of hardware and software resources. Examples of hardware resources include processors, ROMs, RAMs, and other LSIs. Examples of software resources include operating systems, applications, and other programs. [Industrial Applicability]

[0048] The present invention relates to a combustion device for generating combustion. [Explanation of symbols]

[0049] 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

1. a combustion chamber in which combustion occurs; a hydrogen storage material supply unit that supplies a hydrogen storage material capable of releasing stored hydrogen when heated to the combustion chamber; Equipped with The combustion device, wherein the hydrogen storage material is a hydrogen storage alloy.

2. The combustion device of claim 1 , wherein the hydrogen storage material is in granular form.

3. The combustion device according to claim 2 , further comprising a crushing unit that crushes the hydrogen storage material into granules before the hydrogen storage material is supplied to the combustion chamber.

4. The combustion device according to claim 2 or 3, further comprising a circulation section that collects the granular hydrogen storage material that has come out of the combustion chamber and returns the collected hydrogen storage material to the combustion chamber.

5. The combustion device according to claim 1 , further comprising a recovery section that recovers the hydrogen storage material from a bottom of the combustion chamber.

6. The combustion device according to claim 5 , wherein the hydrogen storage material is magnetic, and the recovery unit further comprises a magnetic separation unit that separates the hydrogen storage material by magnetism.

7. The combustion device according to claim 1 , further comprising a fuel supply unit that supplies a fuel different from the hydrogen storage material to the combustion chamber.

8. The combustion apparatus according to any one of claims 1 to 3, wherein the combustion apparatus is any one of a circulating fluidized bed boiler, a bubbling fluidized bed boiler, and a rotary kiln.

9. 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 the hydrogen released from the hydrogen storage material in the combustion chamber; Equipped with The combustion method, wherein the hydrogen storage material is a hydrogen storage alloy.

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