JP5969540B2 - Gasification combustion method for combustibles - Google Patents

Description

  The present invention relates to a method for gasifying and combusting combustibles capable of treating the combustibles such as industrial waste and general waste by high-temperature combustion while suppressing the emission of carbon dioxide.

  In boilers, fossil fuels such as petroleum and pulverized coal are completely burned in order to obtain heat energy with high efficiency. In order to perform complete combustion, it is necessary to supply air necessary for combustion to the fuel. By supplying air necessary for combustion, high-temperature heat energy can be generated, and thereby high-temperature hot water or high-temperature and high-pressure steam can be generated using a heat exchanger or the like. In thermal power generation, power is generated by rotating a steam turbine with high-temperature and high-pressure steam.

  However, in the above method, there is a problem that fuel loss increases because excess air is supplied to completely burn fossil fuel and the like. In addition, in the combustion process of fossil fuel, etc. performed to obtain thermal energy, when the fossil fuel at normal temperature and oxygen-containing gas are combusted, the initial temperature in the combustion furnace rises from normal temperature to about 450 ° C. In the stage, a large amount of carbon monoxide is generated. After that, the temperature in the combustion furnace rises rapidly, but carbon monoxide is an unstable substance. Therefore, when the temperature in the combustion furnace reaches about 650 ° C., it combines with excess oxygen. As a result, a large amount of carbon dioxide is generated. Since carbon dioxide is a stable substance, it hardly decomposes during the combustion process. For this reason, it is difficult to suppress the generation of carbon dioxide, and a large amount of exhaust gas is discharged into the atmosphere, resulting in deterioration of the natural environment.

JP 11-294735 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for gasifying and burning a combustible that enables significant reduction of carbon dioxide emissions.

  In order to solve the above-mentioned problems, the inventors of the present application have studied a gasification combustion method for a combusted material. As a result, the combustion object is thermally decomposed by supplying oxygen or a gas containing oxygen in an amount smaller than the theoretical ratio in the case where the object to be combusted completely is burned into the primary combustion furnace that has been set to 800 ° C. or higher in advance. Thus, it was found that the generation of carbon monoxide and carbon dioxide can be further suppressed, and the present invention has been completed.

  That is, a gasification combustion method of a combustible according to the present invention is a gasification combustion method of a combustible that burns the combustible using a primary combustion furnace in order to solve the above-described problem, A step of adjusting the initial temperature in the primary combustion furnace to 800 ° C. or higher, and the primary combustion furnace having a temperature of 800 ° C. or higher contains oxygen or oxygen in an amount less than the theoretical ratio in the case where the combusted material completely burns. Supplying a gas into the primary combustion furnace at 800 ° C. or higher to generate an unburned gas by thermally decomposing the burned material, and causing incomplete combustion to generate smoke. The oxygen or oxygen-containing gas is supplied continuously or intermittently while forcibly exhausting and depressurizing the inside of the primary combustion furnace as the unburned gas and soot. Generate something over 1000 ℃ Together, wherein said reducing by further thermally decomposing at least a portion of the non-volatile components generated by thermal decomposition of the combustibles.

  According to the above configuration, first, the temperature in the primary combustion furnace is adjusted to an extremely high temperature state of 800 ° C. or higher before the combusted material is burned. Thereafter, oxygen or a gas containing oxygen is supplied into the primary combustion furnace. In addition, the combusted material is also supplied into the primary combustion furnace. When the combusted material is supplied into the primary combustion furnace, the combusted material is thermally decomposed because the primary combustion furnace is at a high temperature of 800 ° C. or higher. Thereby, the gasified volatile component is generated as unburned gas among the decomposition products of the combusted material. Further, a part of the combusted material is incompletely combusted because the amount of oxygen or the like supplied into the primary combustion furnace is less than the theoretical ratio that enables complete combusting of the combusted material. As a result, a large amount of high-temperature soot is generated.

  Here, the supply of oxygen or the like is performed continuously or intermittently while forcibly exhausting the unburned gas from the primary combustion furnace and reducing the pressure. It happens at high temperatures. As a result, unburned gas and soot of 1000 ° C. or higher are generated, and the temperature in the primary combustion furnace becomes 1000 ° C. or higher. Thereby, it becomes possible to further thermally decompose at least a part of the nonvolatile components generated by the thermal decomposition of the combusted material, and the generation amount of the nonvolatile components can be suppressed. In addition, the amount of carbon monoxide generated can be suppressed, and even when carbon monoxide is contained in the soot, the oxygen supplied into the primary combustion furnace is less than the theoretical ratio that completely burns the combusted material. Therefore, the amount of carbon dioxide is suppressed from changing to carbon dioxide. And since the inside of a primary combustion furnace will be in the high temperature state of 1000 degreeC or more, carbon monoxide can also be thermally decomposed and generation | occurrence | production of a carbon dioxide can be suppressed further.

  In the above configuration, the unburned gas and soot generated at 1000 ° C. or more generated in the primary combustion furnace are supplied to the pre-combustion furnace, and the unburned gas and soot are completely burned in the pre-combustion furnace. It is preferable to include a step of thermally decomposing the unburned gas and soot by bringing it into contact with a gas having a smaller amount of oxygen or oxygen than the theoretical ratio in the case of 50 ° C to 300 ° C.

  According to the above configuration, the soot and unburned gas can be pyrolyzed by bringing the unburned gas generated in the primary combustion furnace into contact with oxygen or a gas containing oxygen in the preliminary combustion furnace. . Here, since the oxygen or the like is a high temperature of 50 ° C. to 300 ° C., the thermal decomposition of soot and unburned gas is performed in a higher temperature atmosphere. Therefore, the thermal decomposition can be performed more efficiently. However, since the amount of oxygen etc. supplied to the pre-combustion furnace is less than the theoretical ratio when the unburned gas etc. is completely burned, the carbon monoxide contained in soot and unburned gas etc. It can suppress that the carbon monoxide which generate | occur | produces at a process changes to a carbon dioxide. That is, with the above configuration, unburned gas and the like can be further thermally decomposed while suppressing the generation of carbon dioxide.

  Further, in the above-described configuration, the initial temperature in the secondary combustion furnace is adjusted to 800 ° C. or higher, and the unburned gas or soot is completely burned in the secondary combustion furnace at 800 ° C. or higher. A step of supplying oxygen or oxygen-containing gas in an amount smaller than the theoretical ratio, and unburned gas and soot discharged from the primary combustion furnace or pre-combustion furnace in the secondary combustion furnace at 800 ° C. or higher. And the step of thermally decomposing the unburned gas and soot.

  According to the above configuration, before the unburned gas and soot generated in the primary combustion furnace or the precombustion furnace are combusted, the temperature in the secondary combustion furnace is first adjusted to an extremely high temperature state of 800 ° C. or higher. . Thereafter, oxygen or a gas containing oxygen is supplied into the secondary combustion furnace. Moreover, unburned gas etc. are also supplied into the secondary combustion furnace. When unburned gas is supplied into the secondary combustion furnace, the temperature in the secondary combustion furnace is at a high temperature of 800 ° C or higher, so the unburned gas is completely pyrolyzed and the amount of carbon monoxide generated There are few. In addition, even when carbon monoxide is included, oxygen or the like supplied into the secondary combustion furnace is less than the theoretical ratio for completely burning the unburned gas, so it changes to carbon dioxide. Is suppressed. In addition, since the inside of the secondary combustion furnace is at a higher temperature than the initial temperature of 800 ° C., carbon monoxide can also be thermally decomposed, and generation of carbon dioxide can be further suppressed.

  Further, in the above-described configuration, a fine powder and / or liquid fossil fuel is used as the combusted material, and the fine powder and / or liquid fossil fuel is sprayed in the form of a mist, and the primary It is preferable to supply into the combustion furnace. By spraying fine powder and / or liquid fossil fuel as the combusted material and supplying it into the primary combustion furnace, gasification of the combusted material at a high temperature can be performed more efficiently.

The present invention has the following effects by the configuration described above.
That is, according to the present invention, the combusted material is supplied into the primary combustion furnace whose initial temperature is adjusted to 800 ° C. or higher, so that the combusted material can be pyrolyzed to generate unburned gas. . The amount of oxygen or oxygen-containing gas supplied to the primary combustion furnace is less than the theoretical ratio that enables complete combustion of the combusted material, so that the combusted material is incompletely combusted and smoke is generated. Can be made. Here, although carbon monoxide is also contained in the smoke, since the oxygen in the primary combustion furnace is insufficient, it is possible to suppress the conversion of carbon monoxide to carbon dioxide. Moreover, since the inside of a primary combustion furnace will be in the high temperature state of 1000 degreeC or more, carbon monoxide is thermally decomposed. As a result, according to the present invention, it is possible to provide a method for gasifying and combusting combustibles that can significantly reduce carbon dioxide emissions.

It is a perspective view which shows the outline of the gasification combustion apparatus which concerns on this Embodiment. It is a perspective view which shows the air path of the precombustion furnace in the said gasification combustion apparatus.

  A method for gasifying and combusting combustibles according to the present embodiment will be described below with reference to FIGS. FIG. 1 is an explanatory diagram showing an outline of a gasification combustion apparatus according to the present embodiment. FIG. 2 is a perspective view showing an air path of a pre-combustion furnace in the gasification combustion apparatus.

  First, the gasification combustion apparatus used for the gasification combustion method of this Embodiment is demonstrated. As shown in FIG. 1, the gasification combustion apparatus 13 significantly reduces the emission of carbon dioxide and enables combustion of the combusted material, and includes a primary combustion furnace 10, a preliminary combustion furnace 11, and a secondary combustion. At least a furnace 12 and a cyclone 15 are provided. The preliminary combustion furnace 11 is provided between the primary combustion furnace 10 and the secondary combustion furnace 12. The primary combustion furnace 10 is connected to the preliminary combustion furnace 11 through the first communication pipe 5. Further, the preliminary combustion furnace 11 is connected to the secondary combustion furnace 12 via the second communication pipe 8. Further, the cyclone 15 is connected to the secondary combustion furnace 12 via the discharge pipe 32.

  The burned material is not particularly limited, and examples thereof include waste such as general waste or industrial waste, fossil fuel, biomass fuel, livestock manure, and the like. The fossil fuel is not particularly limited, and examples thereof include fine pulverized coal, natural gas, liquid petroleum, heavy oil, and kerosene in addition to coal.

  The primary combustion furnace 10 generates unburned gas and soot by thermally decomposing and incompletely burning the combustion object. In the furnace body 1 of the primary combustion furnace 10, a hearth 2 for placing a combustible is provided on the lower side from the center of the inside. The hearth 2 preferably has air permeability. Thereby, oxygen can be efficiently supplied to the combustible. The hearth 2 has, for example, an upper beam and a lower beam, and is made of a heat-resistant metal (for example, stainless steel) or ceramics between them, and has a mesh shape, a porous shape, a honeycomb shape, a fiber shape, a whisker. A member provided with a member having a shape or a combination of two or more of these can be used. A plurality of hearths 2 can be provided. In this case, each hearth can be arranged vertically with an arbitrary distance. Further, the furnace body 1 is provided with a shooter 3 as a combustible material supply means for supplying the combustible material on the hearth 2. Further, a burner 4 as temperature adjusting means is provided at an arbitrary position of the furnace body 1 in order to adjust the initial temperature inside the primary combustion furnace 10. A plurality of burners 4 may be provided.

  The furnace body 1 has a rectangular parallelepiped shape having heat resistance, and a part of the top portion thereof preferably has, for example, an inclined surface. The inclined surface is inclined toward the wall surface opposite to the wall surface on which the first communication pipe 5 is provided. Thereby, unburned gas and soot generated in the primary combustion furnace 10 are easily discharged toward the first communication pipe 5. The first communication pipe 5 is provided at the upper part of the furnace body 1, thereby making it easy for unburned gas and soot rising toward the upper part of the furnace body 1 to be discharged toward the first communication pipe 5. . A discharge port 14 is provided below the hearth 2 for discharging incineration ash generated after combustion of the combusted material. Furthermore, a refractory brick 6 is provided at the bottom of the furnace body 1.

  The shooter 3 is provided with an electric lid 7, and the electric lid 7 can be moved up and down as indicated by arrows by an electric hoisting device (not shown). Further, the primary combustion furnace 10 is provided with an electric pusher 9 for supplying the combusted material into the primary combustion furnace 10. The electric pusher 9 moves in a direction indicated by an arrow when the electric lid 7 is in an open state, thereby pushing the combusted material and supplying the combusted material into the primary combustion furnace 10 via the shooter 3.

  The combustible material supply means is not limited to the shooter 3 mode. For example, a fine fossil fuel such as pulverized coal or a liquid fossil fuel such as petroleum may be used as the combusted material, and these may be sprayed downward from the upper part of the primary combustion furnace 10. By supplying the combusted material into the primary combustion furnace 10 by such a method, it is possible to achieve efficient thermal decomposition of the combusted material.

  The burner 4 is temperature adjusting means for adjusting the initial temperature inside the primary combustion furnace 10. The type of the burner 4 is not particularly limited, and for example, those using kerosene, heavy oil, natural gas or the like as fuel can be used.

  In the present embodiment, the burner 4 also has a function as supply means for supplying oxygen or a gas containing oxygen into the primary combustion furnace 10. Specifically, when the burner 4 is burned and the initial temperature inside the primary combustion furnace 10 reaches 800 ° C. or higher, the supply of fuel for the burner 4 is stopped and only oxygen or a gas containing oxygen is supplied. to continue. Thereby, it functions as supply means for supplying oxygen or a gas containing oxygen into the primary combustion furnace 10. The burnable material can be supplied after the supply of fuel for the burner 4 is stopped and before oxygen or a gas containing oxygen is supplied.

  Here, the supply amount of oxygen or oxygen-containing gas by the burner 4 is set to an amount smaller than the theoretical ratio that enables complete combustion of the combusted material. Thereby, a to-be-combusted object can be thermally decomposed and incompletely burned at high temperature. Further, by not supplying a sufficient amount of oxygen, generation of carbon monoxide and carbon dioxide can be suppressed. About the specific value of the supply amount of oxygen or the gas containing oxygen, it can set suitably by the kind etc. of a to-be-combusted object. In addition, it does not specifically limit as said gas containing oxygen, For example, air etc. are mentioned.

  The pre-combustion furnace 11 burns the unburned gas or the like by bringing the unburned gas and soot generated in the primary combustion furnace 10 into contact with oxygen or a gas containing oxygen. As shown in FIG. 1, a first communication pipe 5 for connecting to the primary combustion furnace 10 is connected to the preliminary combustion furnace 11. Smoke, unburned gas, and the like discharged from the primary combustion furnace 10 are introduced from the first communication pipe 5 into the internal flue 21 through the first communication pipe inlet 5a.

  In addition, an air passage 23 for introducing oxygen or a gas containing oxygen is provided in the upper portion of the preliminary combustion furnace 11. The air passage 23 is connected to an air intake pipe 22, and the air intake pipe 22 is connected to a blower 25 for taking in air. The air passage 23 is provided with a cooling pipe 24 for circulating the cooling water to cool the air passage 23. A perforated plate 11a is disposed at the end of the air passage 23, and oxygen or the like is injected from the holes of the perforated plate 11a toward the flow direction of soot and unburned gas (see FIG. 2). A refractory brick 6 is provided at the bottom of the preliminary combustion furnace 11.

  The secondary combustion furnace 12 completely burns unburned gas and soot that have not been burned in the preliminary combustion furnace 11. A second communication pipe 8 for communicating with the preliminary combustion furnace 11 is connected to the furnace body 31 of the secondary combustion furnace 12. Thereby, the unburned gas, the soot, etc. which are discharged | emitted from the preliminary combustion furnace 11 can be introduce | transduced inside. The secondary combustion furnace 12 is a temperature adjusting means for adjusting the initial temperature inside the secondary combustion furnace 12, and is also a supply means for supplying oxygen or a gas containing oxygen into the secondary combustion furnace 12. A burner 4 is provided. Further, in the furnace body 31, the hearth 2 is provided on the lower side from the center in the inside thereof, as in the case of the primary combustion furnace 10. The hearth 2 preferably has air permeability. By providing the hearth 2, high-temperature soot and the like discharged from the pre-combustion furnace 11 can be passed, and further thermal decomposition is possible. A plurality of hearths 2 can be provided as in the case of the primary combustion furnace 10. Furthermore, an exhaust pipe 32 for exhausting waste gas is provided at the upper part of the secondary combustion furnace 12. In the secondary combustion furnace 12, a discharge port 14 for discharging incinerated ash generated after combustion of the combusted material is provided below the hearth 2. A refractory brick 6 is provided at the bottom.

  The cyclone 15 collects exhaust gas such as soot discharged from the secondary combustion furnace 12, and has a function of cooling the exhaust gas in a high temperature state to about 200 ° C. The cyclone 15 has at least a conical portion 28 and a dust collecting portion 29 provided below the conical portion 28. The conical portion 28 is provided so as to converge in a conical shape toward the lower dust collecting portion 29. The dust collection unit 29 collects soot separated from the exhaust gas discharged from the secondary combustion furnace 12. Further, an exhaust cylinder 27 is provided on the upper portion of the conical portion 28. Further, the exhaust cylinder 27 is provided with a blower 26 for supplying air.

Subsequently, the gasification combustion method for the combustible of the present embodiment will be described.
In the gasification combustion method of the present embodiment, first, a step of adjusting the initial temperature inside the primary combustion furnace 10 to 800 ° C. or more is performed. The initial temperature is adjusted by burning the burner 4. Although the initial temperature of the primary combustion furnace 10 will not be specifically limited if it is 800 degreeC or more, Preferably it is 850 degreeC or more. The initial temperature can be appropriately set within the temperature range according to the type of the combusted material. By setting the initial temperature of the primary combustion furnace 10 to 800 ° C. or higher, it becomes possible to cause a thermal decomposition reaction of the combusted material. The upper limit of the initial temperature is preferably set as appropriate in consideration of the subsequent temperature rise in the furnace and the heat resistance of the primary combustion furnace 10. The initial temperature in the primary combustion furnace 10 is a value measured in the vicinity of the top surface of the primary combustion furnace 10.

  Next, oxygen or a gas containing oxygen is supplied into the primary combustion furnace 10. The supply of oxygen or a gas containing oxygen is performed while forcibly exhausting the inside of the primary combustion furnace 10 and reducing the pressure. Here, forced exhaust in the primary combustion furnace 10 is performed by a blower 25 provided in the preliminary combustion furnace 11 and a blower 26 provided in a cyclone 15 described later. In the present embodiment, after the burner 4 is combusted and the initial temperature inside the primary combustion furnace 10 is set to 800 ° C. or higher, the fuel supply for the burner 4 is stopped and only oxygen or a gas containing oxygen is supplied. Continue to supply. As a result, oxygen or a gas containing oxygen can be supplied into the primary combustion furnace 10. The supply of oxygen or a gas containing oxygen can be performed continuously or intermittently. Moreover, the forced exhaust in the primary combustion furnace 10 can also be performed continuously or intermittently. The supply amount of oxygen or a gas containing oxygen is an amount smaller than the theoretical ratio in the case where the combusted material completely burns.

  Subsequently, the combusted material is supplied into the primary combustion furnace 10. The combustibles are supplied from the shooter 3 and placed on the hearth 2. In addition, you may supply a to-be-combusted material before supplying oxygen or the gas containing oxygen. Or you may carry out simultaneously with supply of the gas containing oxygen or oxygen, or after supply. Further, in this step, forced exhaust in the primary combustion furnace 10 can also be performed continuously or intermittently.

  When the combusted material is put into the primary combustion furnace 10 in an atmosphere of 800 ° C. or higher, the combusted material undergoes a thermal decomposition reaction. Thereby, the decomposition product of a to-be-combusted material arises. Among the decomposition products, volatile components are generated as unburned gas. Unburned gas includes flammable gases such as hydrocarbons. Further, the unburned gas generated is in a very high temperature (for example, 1000 ° C. or higher) as will be described later. In addition, since the primary combustion furnace 10 is in a state where oxygen is insufficient, the combustible is incompletely combusted, and soot containing carbon monoxide is also generated. However, since the temperature in the primary combustion furnace 10 is a high temperature of 1000 ° C. or higher and oxygen is low, carbon monoxide is thermally decomposed without changing to carbon dioxide. As a result, a large amount of black smoke (smoke) of 1000 ° C. or higher is generated. The soot includes, for example, carbon fine particles.

  Here, in this step, as described above, pressure reduction by forced exhaust in the primary combustion furnace 10 is performed. Then, high-temperature soot or the like is sent into the preliminary combustion furnace 11 and the secondary combustion furnace 12. For this reason, the residence time of a large amount of high-temperature unburned gas or high-temperature soot generated in the primary combustion furnace 10 in the furnace is short. On the other hand, since oxygen or a gas containing oxygen is continuously supplied into the primary combustion furnace 10 continuously or intermittently, the amount to be burned is less than the theoretical ratio in the case of complete combustion. Of oxygen is always supplied. As a result, the incomplete combustion of the combusted material is also maintained, so that the temperature in the primary combustion furnace 10 rises from the initial temperature of 800 ° C. to about 1000 ° C. to 1400 ° C. in a very short time.

  Moreover, in the non-volatile component (for example, when the combustible is a carbon compound, solid carbon content having low volatility) among the decomposition products, the temperature inside the primary combustion furnace 10 is 1000 ° C. or higher. Since it is in a high temperature state, thermal decomposition occurs. Thereby, in the present embodiment, the volume and volume of the non-volatile component can be reduced.

  In order to prevent the in-furnace temperature of the primary combustion furnace 10 from rising beyond the heat resistance performance of the primary combustion furnace 10, the in-furnace temperature may be controlled. Examples of the method for controlling the furnace temperature include adjustment of the supply amount of oxygen or a gas containing oxygen supplied into the primary combustion furnace 10, adjustment of the exhaust speed, and the like.

  Subsequently, a large amount of unburned gas and soot generated and discharged in the primary combustion furnace 10 is introduced into the preliminary combustion furnace 11 through the first communication pipe 5. In the preliminary combustion furnace 11, high-temperature oxygen or a gas containing oxygen is introduced from the air passage 23. The temperature of oxygen or a gas containing oxygen may be room temperature, but is preferably in the range of 50 ° C to 300 ° C. By introducing oxygen at normal temperature or a gas containing oxygen, it becomes possible to thermally decompose unburned gas and soot in the pre-combustion furnace 11, but the temperature of oxygen or the like is within the above numerical range. As a result, the inside of the pre-combustion furnace 11 is in a higher temperature state, specifically, a high temperature state of 900 ° C. or higher or 1100 ° C. or higher. Therefore, it becomes possible to perform thermal decomposition of unburned gas and soot. Moreover, since carbon monoxide is also thermally decomposed, the generation of carbon dioxide can be further reduced. However, the supply amount of oxygen or oxygen-containing gas supplied into the pre-combustion furnace 11 is smaller than the theoretical ratio when unburned gas, soot, etc. are completely burned. For this reason, oxygen is insufficient in the pre-combustion furnace 11 as well. Thereby, the change from carbon monoxide to carbon dioxide is suppressed.

  Subsequently, the high-temperature exhaust gas discharged from the preliminary combustion furnace 11 is supplied to the secondary combustion furnace 12 through the second communication pipe 8 by forced exhaust. The forced exhaust is performed by a blower 25 provided in the preliminary combustion furnace 11 and a blower 26 provided in a cyclone 15 described later. In the secondary combustion furnace 12, the internal initial temperature (temperature in the vicinity of the top surface) is adjusted in advance to be 800 ° C. or higher, more preferably 850 ° C. or higher before supplying exhaust gas. . Examples of temperature adjusting means for adjusting the temperature in the secondary combustion furnace 12 include a burner used in the primary combustion furnace 10. The installation position of the burner or the like is not particularly limited, and can be provided at an arbitrary position as necessary. A plurality of temperature adjusting means such as a burner may be provided. The upper limit of the initial temperature of the secondary combustion furnace 12 is preferably set as appropriate in consideration of the subsequent temperature rise in the furnace and the heat resistance of the secondary combustion furnace.

  In the secondary combustion furnace 12, oxygen or a gas containing oxygen is supplied. Supply of oxygen or the like is performed while forcibly exhausting the inside of the secondary combustion furnace 12. In the present embodiment, after the burner is burned to raise the initial temperature inside the secondary combustion furnace 12 to 800 ° C. or higher, the supply of fuel for the burner is stopped and only oxygen or a gas containing oxygen is supplied. Keep doing. As a result, oxygen or a gas containing oxygen can be supplied into the secondary combustion furnace 12. The supply of oxygen or a gas containing oxygen can be performed continuously or intermittently. The supply amount of oxygen or a gas containing oxygen is smaller than the theoretical ratio in the case where unburned gas, soot, etc. are completely burned.

  The temperature in the furnace when the unburned gas and soot are incompletely burned in the secondary combustion furnace 12 is maintained within a range of 1000 ° C to 1300 ° C. Thereby, the unburned gas etc. supplied to the secondary combustion furnace 12 can be completely thermally decomposed. Even when carbon monoxide is present, the secondary combustion furnace 12 is in a state where oxygen is insufficient, so that it does not change to carbon dioxide. Furthermore, since the inside of the secondary combustion furnace 12 is in a high temperature state of 1000 ° C. or higher, carbon monoxide is thermally decomposed. The exhaust gas generated in the secondary combustion furnace 12 is then forcibly exhausted from the exhaust pipe 32. Here, the forced exhaust of the exhaust gas (including the forced exhaust in the primary combustion furnace 10 and the precombustion furnace 11) is that the blower 26 in the cyclone 15 blows air to the exhaust cylinder 27. Is done by. That is, when the blower 26 blows air to the exhaust cylinder 27, the conical portion 28 of the cyclone 15 is in a negative pressure state. As a result, the high-temperature exhaust gas generated in the secondary combustion furnace 12 is drawn from the exhaust pipe 32 to the conical portion 28 of the cyclone 15.

  Next, the exhaust gas drawn into the cyclone 15 is blown toward the tangential direction of the inner wall surface of the conical portion 28. The exhaust gas forms a spiral flow. Since the dust in the exhaust gas has a weight, it is captured by this spiral flow and flows down while rotating in the conical portion 28. Thereafter, the soot deposits on the dust collecting portion 29. On the other hand, the clean exhaust gas separated from the dust is discharged to the outside along with the air sent from the blower 26 from the exhaust cylinder 27 above the conical portion 28.

  Here, since the air supplied from the blower 26 is normal temperature, the exhaust gas supplied to the cyclone 15 is cooled. Specifically, high-temperature exhaust gas of about 1000 ° C. to 1300 ° C. is cooled to about 200 ° C. This makes it possible to suppress the generation of harmful substances such as dioxins.

  In the present embodiment, when the unburned material such as unburned gas can be burned completely in the preliminary combustion furnace 11, the processing in the secondary combustion furnace 12 can be omitted. . In that case, the waste gas discharged from the preliminary combustion furnace 11 is forcibly exhausted directly to the cyclone 15 or the like.

  As described above, in the gasification combustion method for a combusted material according to the present embodiment, the combusted material can be combusted while suppressing the emission of carbon dioxide as compared with the conventional method.

(Other matters)
In the gasification combustion method for combustibles according to the present embodiment, since the furnace temperatures of the primary combustion furnace and the secondary combustion furnace become extremely high, waste heat is used as a thermal energy source for boilers and power generators. can do. When used as a thermal energy source for a boiler, waste heat can be used by connecting a heat exchanger (not shown) to the primary combustion furnace or the secondary combustion furnace. When used as a thermal energy source for power generation, for example, a gas turbine can be connected to a secondary combustion furnace, and power can be generated by driving a generator connected to the gas turbine.

  In conventional boilers and power generation devices, a large amount of carbon dioxide is generated when burning fossil fuel or the like to obtain thermal energy, but in this embodiment, oxygen is insufficient. Since the combustibles are burned in this way, even if carbon monoxide is generated, it is possible to suppress the change to carbon dioxide. In addition, since the inside of the primary combustion furnace is at a high temperature of 1000 ° C., carbon monoxide can be thermally decomposed. As a result, carbon dioxide emissions can be reduced as compared with conventional boilers and power generators.

  Furthermore, hydrocarbons may be synthesized using high-temperature water produced by the heat exchanger. In this case, the reaction chamber for synthesizing the hydrocarbon is placed in an atmosphere of 220 to 270 ° C. using the high-temperature water, and the mixed gas of carbon monoxide and hydrogen is converted into an iron-based catalyst, a cobalt-based catalyst, or a ruthenium-based catalyst. Hydrocarbons can be synthesized by Fischer-Tropsch reaction. The obtained hydrocarbons may be reused as combustibles in the gasification combustion method of the present embodiment. Further, the electricity generated by the above method may be used as an energy source for water electrolysis. Hydrogen obtained by electrolysis of water can be reused for the synthesis of the hydrocarbon.

1 furnace body 2 hearth 3 shooter 4 burner 5 communication pipe 5a communication pipe inlet 6 refractory brick 7 electric lid 8 communication pipe 9 electric pusher 10 primary combustion furnace 11 preliminary combustion furnace 11a perforated plate 12 secondary combustion furnace 13 gasification combustion Device 14 Discharge port 15 Cyclone 21 Flue 22 Air intake pipe 23 Air path 24 Cooling pipes 25 and 26 Blower 27 Exhaust cylinder 28 Conical part 29 Dust collecting part 31 Furnace body 32 Exhaust pipe

Claims (3)

A method for gasifying and combusting a combustible to burn the combustible using at least a primary combustion furnace , a preliminary combustion furnace, and a secondary combustion furnace ,
Adjusting the initial temperature in the primary combustion furnace to 800 ° C. or higher;
In the primary combustion furnace at 800 ° C. or higher, the amount of oxygen or a gas containing oxygen that is smaller than the theoretical ratio in the case where the combusted substance completely burns is continuously exhausted while reducing the pressure by forcibly exhausting the inside of the primary combustion furnace. Supplying automatically or intermittently ;
In the primary combustion furnace to which the oxygen or a gas containing oxygen is supplied , the combusted material is supplied, and the combusted material is thermally decomposed to generate an unburned gas of 1000 ° C. or higher. is completely combusted to generate a 1000 ° C. or more soot by a further said Ru at least part of the non-volatile components generated by thermal decomposition of the combustion was reduced by pyrolysis step,
Supplying the unburned gas and soot generated at 1000 ° C. or higher generated in the primary combustion furnace to the preliminary combustion furnace, and in the preliminary combustion furnace, the theoretical ratio when the unburned gas and soot completely burns A step of thermally decomposing the unburned gas and soot by contacting a small amount of oxygen or a gas containing oxygen with a gas of 50 ° C. to 300 ° C .;
Adjusting the initial temperature in the secondary combustion furnace to 800 ° C. or higher;
A step of supplying oxygen or a gas containing oxygen in an amount less than a theoretical ratio in a case where unburned gas and soot discharged from the preliminary combustion furnace completely burn in the secondary combustion furnace at 800 ° C. or higher;
Gasification of a combusted material including a step of supplying unburned gas and soot discharged from the preliminary combustion furnace into the secondary combustion furnace at 800 ° C. or higher and thermally decomposing the unburned gas and soot Combustion method. A method for gasifying and combusting combustibles according to claim 1,
The step of adjusting the initial temperature in the primary combustion furnace to 800 ° C. or higher and the step of adjusting the initial temperature in the secondary combustion furnace to 800 ° C. or higher are provided in the primary combustion furnace and the secondary combustion furnace. It is done by burning each burner,
A step of supplying oxygen or a gas containing oxygen in an amount less than a theoretical ratio in the case where the combusted substance completely burns into the primary combustion furnace at 800 ° C. or higher, and the secondary combustion furnace at 800 ° C. or higher; In addition, the step of supplying oxygen or a gas containing oxygen in an amount less than the theoretical ratio in the case where the unburned gas and soot completely burn, stops supplying fuel for the burner in each of the burners, and Alternatively, a method for gasifying and burning combustibles, which is performed by supplying only a gas containing oxygen . A method for gasifying and combusting combustibles according to claim 1 or 2,
A combustible material that uses fine powder and / or liquid fossil fuel as the combusted material , sprays the fine powder and / or liquid fossil fuel in a mist, and supplies the fuel into the primary combustion furnace . Gasification combustion method.

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