Heat utilization system and heat supply method

Abstract

The present invention addresses the problem of effectively utilizing heat generated in either a methanation facility or an incineration facility by the other of the methanation facility and the incineration facility. The heat utilization system comprises: a methanation device for generating methane from hydrogen and carbon dioxide; the incineration equipment is provided with an incinerator; and a heat supply unit for supplying heat generated in one of the methanation facility and the incineration facility to the other of the methanation facility and the incineration facility.

Description

TECHNICAL FIELD

[0001] The present application relates to a heat utilization system and a heat supply method. BACKGROUND

[0002] As a measure for reducing the amount of carbon dioxide discharged in the existing incineration facility, classification and recycling of waste such as plastic derived from fossil fuels, or power generation using heat generated along with waste incineration is promoted. In the trend toward decarbonization in recent years, decarbonization of the incineration facility is also expected, and separation, recovery, and effective use of carbon dioxide in the exhaust gas generated by waste incineration are required. Methanation, which is a reaction of carbon dioxide with hydrogen to generate methane gas, is attracting attention as one of the technologies related to the effective use of carbon dioxide. In Patent Literature 1, a method and an apparatus for manufacturing methane by reacting carbon dioxide with hydrogen using a catalyst are disclosed. In Patent Literature 1, reaction heat generated by the catalyst reaction is used to generate steam from cooling water, and the generated steam is used as heat energy for separating carbon dioxide. In Patent Literature 2, a system in which a methanation apparatus and a waste power generation device are provided together is disclosed.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Laid-Open No. 2020-63206

[0006] Patent Literature 2: Japanese Patent Laid-Open No. 2020-45430 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] With regard to effective use of heat generated in a methanation apparatus by an incineration facility, or effective use of heat generated in an incineration facility by a methanation apparatus, sufficient research has not been conducted in the past.

[0009] An object of the present application is to provide a technology that enables heat generated in one of a methanation apparatus and an incineration facility to be effectively used by the other of the methanation apparatus and the incineration facility.

[0010] TECHNICAL MEANS FOR SOLVING THE PROBLEM

[0011] The present application for solving the problem is a heat utilization system including: a methanation device that generates methane from hydrogen and carbon dioxide; an incineration device having an incinerator; and a heat supply portion that supplies heat generated in one of the methanation device and the incineration device to the other of the methanation device and the incineration device. According to the heat utilization system, heat generated in one of the methanation device and the incineration device is supplied to the other of the methanation device and the incineration device. Thus, heat generated in one of the methanation device and the incineration device can be effectively utilized by the other of the methanation device and the incineration device.

[0012] In the heat utilization system, the methanation device can also have a reactor that generates the methane by reacting the hydrogen and the carbon dioxide, and a heat medium circulation line in which a heat medium for adjusting the temperature in the reactor is circulated, and the heat supply portion can be a heat exchanger that exchanges heat between the heat medium flowing in the heat medium circulation line and combustion air supplied to the incinerator. The reaction that generates the methane by reacting the hydrogen and the carbon dioxide is an exothermic reaction. The temperature of the heat medium flowing in the heat medium circulation line rises by adjusting the temperature in the reactor with the heat medium. The heated combustion air is supplied to the incinerator by exchanging heat between the heat medium flowing in the heat medium circulation line and the combustion air supplied to the incinerator. By exchanging heat between the heat medium flowing in the heat medium circulation line and the combustion air supplied to the incinerator and supplying heat generated in the methanation device to the incineration device, the heat generated in the methanation device can be effectively utilized by the incineration device.

[0013] In the heat utilization system, the heat exchanger can be provided in a preheater that preheats the combustion air supplied to the incinerator. For example, in a case where the combustion air is preheated with steam, a portion of the steam generated in a boiler is consumed in the preheater. In the heat utilization system, the heat exchanger provided in the preheater exchanges heat between the heat medium flowing in the heat medium circulation line and the combustion air supplied to the incinerator, so the amount of consumption of steam in the preheater can be reduced, and thus the amount of supply of steam for power generation can be increased.

[0014] In the heat utilization system, the heat exchanger can be provided in an exhaust gas heater that heats the exhaust gas discharged from the incinerator. For example, in a case where the exhaust gas is heated using steam, a part of the steam generated in a boiler is consumed in the exhaust gas heater. In the heat utilization system, the heat exchanger provided in the exhaust gas heater exchanges heat between the heat medium circulating in the heat medium circulation line and the exhaust gas discharged from the incinerator, so the amount of consumption of the steam in the exhaust gas heater can be reduced, and thus the amount of supply of the steam for power generation can be increased.

[0015] In the heat utilization system, the heat exchanger can be provided in an exhaust gas heater that heats the exhaust gas discharged from the incinerator. For example, in a case where the exhaust gas is heated using steam, a part of the steam generated in a boiler is consumed in the exhaust gas heater. In the heat utilization system, the heat exchanger provided in the exhaust gas heater exchanges heat between the heat medium circulating in the heat medium circulation line and the exhaust gas discharged from the incinerator, so the amount of consumption of the steam in the exhaust gas heater can be reduced, and thus the amount of supply of the steam for power generation can be increased.

[0016] In the heat utilization system, the heat exchanger can be provided in an exhaust gas heater that heats the exhaust gas discharged from the incinerator. For example, in a case where the exhaust gas is heated using steam, a part of the steam generated in a boiler is consumed in the exhaust gas heater. In the heat utilization system, the heat exchanger provided in the exhaust gas heater exchanges heat between the heat medium circulating in the heat medium circulation line and the exhaust gas discharged from the incinerator, so the amount of consumption of the steam in the exhaust gas heater can be reduced, and thus the amount of supply of the steam for power generation can be increased.

[0017] In the heat utilization system, the incineration apparatus can also have a recovery device that recovers the carbon dioxide from exhaust gas discharged from the incinerator, and the carbon dioxide recovered by the recovery device can be supplied to the reactor together with the hydrogen. Thus, the amount of carbon dioxide discharged from the incineration apparatus can be reduced.

[0018] In addition, the present application can be a heat supply method that is a heat supply method for a heat utilization system including a methanation apparatus that generates methane from hydrogen and carbon dioxide, and an incineration apparatus that has an incinerator, the heat supply method supplying heat generated in one of the methanation apparatus and the incineration apparatus to the other of the methanation apparatus and the incineration apparatus. According to the heat supply method, heat generated in one of the methanation apparatus and the incineration apparatus is supplied to the other of the methanation apparatus and the incineration apparatus. Thus, heat generated in one of the methanation apparatus and the incineration apparatus can be effectively utilized by the other of the methanation apparatus and the incineration apparatus.

[0019] Effects of the Invention

[0020] Heat generated in one of the methanation apparatus and the incineration apparatus can be effectively utilized by the other of the methanation apparatus and the incineration apparatus. BRIEF DESCRIPTION OF DRAWINGS

[0021] [ Figure 1 ] Figure 1 is a configuration diagram of a heat utilization system of the first embodiment.

[0022] [ Figure 2 ] Figure 2 is a configuration diagram of a methanation apparatus.

[0023] [ Figure 3 ] Figure 3 is a configuration diagram of a heat utilization system of the second embodiment.

[0024] [ Figure 4 ] Figure 4 is a configuration diagram of a heat utilization system of the third embodiment. DETAILED DESCRIPTION

[0025] Hereinafter, an embodiment of the present application will be described. The embodiment shown below is an example of an embodiment of the present application, and does not limit the technical scope of the present application to the following mode.

[0026] <First Embodiment>

[0027] Reference Figure 1 and Figure 2 , the first embodiment will be described. Figure 1 is a configuration diagram of a heat utilization system of the first embodiment. Figure 1The illustrated heat utilization system includes a methanation device 1, an incineration device 2, and a heat exchanger 3 that supplies heat generated in one of the methanation device 1 and the incineration device 2 to the other. The heat exchanger 3 is an example of a heat supply portion. In Figure 1 In the illustrated example, the heat exchanger 3 is provided in the preheater 10. The methanation device 1 generates, for example, a methane gas as a product gas by an exothermic reaction of hydrogen (H2) and carbon dioxide (CO2) in a gaseous state as a raw material gas (reaction gas). If the exothermic reaction is expressed by a chemical reaction formula, it is as follows.

[0028] 4H2+ CO2→ CH4+ 2H2O (1)

[0029] The incineration device 2 includes an incinerator 11, a dust collecting device 12, a blower 13, an exhaust gas treatment device 14, a recuperator 15, an exhaust gas heater 16, an induced draft fan 17, and a chimney 18. The incinerator 11, the dust collecting device 12, the blower 13, the exhaust gas treatment device 14, the recuperator 15, the exhaust gas heater 16, the induced draft fan 17, and the chimney 18 are connected by a flue of the incineration device 2. The preheater 10 preheats combustion air supplied to the incinerator 11. For example, the preheater 10 can be provided in an air supply line (air supply pipe) for supplying the combustion air to the incinerator 11. The combustion air is primary air or secondary air. The combustion air can be outside air or air in a refuse pit of the incinerator 11. The refuse pit of the incinerator 11 is a refuse storage portion that temporarily stores refuse carried in by a refuse collection vehicle. In addition, the combustion air can have a ratio of oxygen to nitrogen changed within a range that does not hinder combustion, and other gas components such as carbon dioxide can be added. Figure 1 In the illustrated example, the preheater 10 is provided outside the incineration device 2, but is not limited to this example, and the preheater 10 can be provided inside the incineration device 2. In the incinerator 11, in the case where the moisture of refuse to be incinerated is large, it is preferable to preheat the combustion air in order to perform complete combustion of the refuse. For example, the combustion air is warmed to a maximum of about 200°C and supplied to the incinerator 11. In addition, the recuperator 15 can be provided outside the incineration device 2, and only a part of the exhaust gas can be supplied to the recuperator 15.

[0030] In the incinerator 11, combustion of waste such as garbage is performed. The incinerator 11 has a boiler 19. The exhaust gas generated by the combustion of the waste in the incinerator 11 is sent to the dust collecting device 12 using a bag filter after heat exchange in the boiler 19. The dust collecting device 12 removes dust such as dust or dust from the exhaust gas. A part of the exhaust gas after the removal of the dust is sent to the exhaust gas treatment device 14. The exhaust gas treatment device 14 is, for example, a wet type exhaust gas treatment device (scrubber). In addition, in order to control the combustion of the incinerator 11, a part of the exhaust gas discharged from the dust collecting device 12 is sent to the incinerator 11 using a blower 13. By returning a part of the exhaust gas to the incinerator 11, it is possible to suppress the case where the incinerator 11 becomes high temperature locally. The exhaust gas sent to the exhaust gas treatment device 14 is cooled in the exhaust gas treatment device 14, and impurities such as HCl or SOx in the exhaust gas are removed. The exhaust gas treatment device 14 sends the exhaust gas to the recovery device 15.

[0031] The recovery device 15 has an absorption tower 20 and a regeneration tower 21. In the absorption tower 20, carbon dioxide contained in the exhaust gas is absorbed by an aqueous solution of an amine compound (hereinafter, referred to as amine solution). The recovery device 15 sends the exhaust gas to an exhaust gas heater 16. By heating the exhaust gas using the exhaust gas heater 16, it is possible to suppress dew condensation of a flue through which the exhaust gas flows and white smoke of the exhaust gas. After heating the exhaust gas using the exhaust gas heater 16, the exhaust gas is subjected to denitration treatment using a catalyst denitration device, and is sent to an induced draft fan 17. The induced draft fan 17 discharges the exhaust gas to the outside (for example, the atmosphere) via a chimney 18. In the absorption tower 20, the amine solution in which carbon dioxide is absorbed is warmed in the regeneration tower 21, and the carbon dioxide is separated from the amine solution. The carbon dioxide separated from the amine solution is mixed with hydrogen, and a raw material gas containing the carbon dioxide and the hydrogen is supplied to the methanation device 1. As a method of recovering carbon dioxide, a method other than the amine type such as a temperature swing adsorption method can also be used. The hydrogen supplied to the methanation device 1 is not particularly limited. The hydrogen can also be supplied to the methanation device 1 from a hydrogen tank in which hydrogen is stored. In this case, the hydrogen can also be supplied to the methanation device 1 via a hydrogen conduit connected to the hydrogen tank. In addition, hydrogen generated by water electrolysis using surplus electric power of a renewable energy source can also be supplied to the methanation device 1. A part of the exhaust gas can also not be sent to the incinerator 11. In addition, the catalyst denitration device can also be included in the exhaust gas treatment device 14.

[0032] In Figure 1In the present embodiment, an example is shown in which a part of the exhaust gas discharged from the dust collecting device 12 is sent to the incinerator 11 via the air blower 13, but the present embodiment is not limited to the example. A part of the exhaust gas discharged from the exhaust gas treatment device 14 can also be sent to the incinerator 11 via the air blower 13. In addition, a part of the exhaust gas discharged from the exhaust gas heater 16 can also be sent to the incinerator 11 via the air blower 13.

[0033] Figure 2 is a configuration diagram of the methanation apparatus 1. The methanation apparatus 1 includes a first stage reactor (reaction column) 101, a first stage gas cooling heat exchanger 102, a second stage reactor (reaction column) 103, a second stage gas cooling heat exchanger 104, a heating device 105, a heat medium heat exchanger 106, a gas-liquid separator 107, a gas-liquid separator 108, and a storage tank 109.

[0034] A raw material gas containing hydrogen and carbon dioxide is supplied to the reactor 101. The reactor 101 generates methane by reacting hydrogen and carbon dioxide. In addition, the reactor 101 generates generated water by the exothermic reaction of hydrogen and carbon dioxide. The reactor 101 is connected to the gas cooling heat exchanger 102. A pipe or a valve or the like is provided on a path connecting the reactor 101 and the gas cooling heat exchanger 102. An economizer 111 is provided on a supply path of the raw material gas supplied to the reactor 101. In the economizer 111, heat exchange is performed between the raw material gas supplied to the reactor 101 and exhaust gas sent out from the reactor 101. The exhaust gas is a product gas, an unreacted raw material gas, or a mixed gas of the product gas and the unreacted raw material gas.

[0035] The gas cooling heat exchanger 102 condenses the generated water (water vapor) generated in the reactor 101. The gas cooling heat exchanger 102 is connected to the gas-liquid separator 107. A pipe or a valve or the like is provided on a path connecting the gas cooling heat exchanger 102 and the gas-liquid separator 107. The gas-liquid separator 107 separates the generated water (liquid) from the product gas, the unreacted raw material gas, or the mixed gas of the product gas and the unreacted raw material gas. The gas cooling heat exchanger 102 and the gas-liquid separator 107 can be integrated, and the gas-liquid separator 107 can be a drain trap. The product gas or the unreacted raw material gas is dissolved in the generated water condensed by the gas cooling heat exchanger 102 or the gas-liquid separator 107, and therefore a degassing device can also be provided.

[0036] The reactor 103 is connected to the gas-liquid separator 107. A pipe or a valve or the like is provided on a path connecting the reactor 103 to the gas-liquid separator 107. A economizer 112 is provided on a path connecting the reactor 103 to the gas-liquid separator 107. In the economizer 112, heat exchange is performed between the feed gas to be fed to the reactor 103 and the feed gas to be fed from the reactor 103. The product gas and the unreacted raw material gas generated in the reactor 101 are fed to the reactor 103 via the economizer 111, the gas cooling heat exchanger 102, the gas-liquid separator 107, and the economizer 112. The reactor 103 causes hydrogen and carbon dioxide to react to generate methane. In addition, the reactor 103 generates generated water by the exothermic reaction of hydrogen and carbon dioxide. By generating the product gas from the unreacted raw material gas in the reactor 103, the methanation apparatus 1 can generate a product gas with a high concentration.

[0037] The reactor 103 is connected to the gas cooling heat exchanger 104. A pipe or a valve or the like is provided on a path connecting the reactor 103 to the gas cooling heat exchanger 104. The gas cooling heat exchanger 104 condenses the generated water (water vapor) generated in the reactor 103. The gas cooling heat exchanger 104 is connected to the gas-liquid separator 108. A pipe or a valve or the like is provided on a path connecting the gas cooling heat exchanger 104 to the gas-liquid separator 108. The gas-liquid separator 108 separates the generated water (liquid) from the product gas, the unreacted raw material gas, or the mixed gas of the product gas and the unreacted raw material gas. The gas cooling heat exchanger 104 and the gas-liquid separator 108 can be integrated, and the gas-liquid separator 108 can be a drain trap. The product gas or the unreacted raw material gas is dissolved in the generated water condensed by the gas cooling heat exchanger 104 or the gas-liquid separator 108, and therefore a degassing device can be provided.

[0038] The product gas is fed from the gas-liquid separator 108 to the storage tank 109. The storage tank 109 stores the product gas. In the gas-liquid separator 107 and the gas-liquid separator 108, a drain valve 113 for draining the generated water is provided. The drain valve 113 can be opened and closed using the buoyancy of a float like a drain trap, or can be opened and closed using an electromagnetic valve by electrically detecting the water level. The generated water is drained from the gas-liquid separator 107 and the gas-liquid separator 108 using the drain valve 113.

[0039] A catalyst is preliminarily filled in the reactor 101 and the reactor 103. The catalyst is a catalyst that promotes the reaction formula (1). The catalyst includes, for example, a stabilized zirconia carrier in which a stabilizing element is solid-solved and which has a crystal structure of a tetragonal system and / or a cubic system, and Ni supported on the stabilized zirconia carrier. The stabilizing element is, for example, at least one transition element selected from the group consisting of Mn, Fe, and Co.

[0040] As shown in Figure 1 and Figure 2 The methanation apparatus 1 has a heat medium circulation line 41 through which a heat medium for adjusting the temperature in the reactors 101 and 103 is circulated. The heat medium is, for example, heat medium oil, water, or steam. The heat medium circulation line 41 has, for example, piping connecting the reactors 101 and 103 and the heat exchanger 3 provided in the preheater 10, but can have other structural components. The reaction for generating methane gas is an exothermic reaction, and in the operation of the methanation apparatus 1, the heat medium is circulated using the heat medium circulation line 41 in order to recover the heat in the reactors 101 and 103, so that the temperature in the reactors 101 and 103 does not become excessively high. The heat medium flowing in the heat medium circulation line 41 is circulated in the methanation apparatus 1 and the preheater 10. Specifically, the heat medium passes through the reactor 101, then passes through the reactor 103, passes through the heat exchanger 3, and then passes through the reactor 101 again.

[0041] The reactors 101 and 103 are of a jacket structure, and in the jacket portion (shell), heat medium that exchanges heat with the heat generating portion in the reactor in which an exothermic reaction is generated can flow in and out. The heating device 105 is connected to the jacket portion of the reactor 101 using piping through which the heat medium flows. In addition, the jacket portion of the reactor 101 is connected to the jacket portion of the reactor 103 using piping through which the heat medium flows. In the piping through which the heat medium flows, a valve or the like is provided. The heating device 105 is a heater that heats the heat medium. The heat medium heated by the heating device 105 passes through the reactor 101 and then passes through the reactor 103. The heating device 105 is mainly used when it is desired to raise the temperature of the heat medium, such as at the time of starting the apparatus. When it is not necessary to raise the temperature of the heat medium, the heating of the heat medium by the heating device 105 can not be performed, or the heat medium can be circulated in the heat medium circulation line 41 while bypassing the heating device 105.

[0042] As shown in Figure 1 and Figure 2As shown, the heat medium that passed through the reactor 103 passes through the heat exchanger 3. In the operation of the methanation apparatus 1, the temperature of the heat medium that passed through the reactor 103 is, for example, about 250°C. The heat exchanger 3 has an internal pipe through which the heat medium passes, and an internal pipe through which combustion air passes. In the heat exchanger 3, the internal pipe through which the heat medium passes and the internal pipe through which the combustion air passes can also be arranged in a manner in which a portion of the internal pipe through which the heat medium passes is adjacent to a portion of the internal pipe through which the combustion air passes. In the heat exchanger 3, heat exchange is performed between the heat medium that passed through the heat exchanger 3 and the combustion air that is supplied to the incinerator 11 through the heat exchanger 3. Thus, the heat exchanger 3 performs heat exchange between the heat medium that flows in the heat medium circulation line 41 and the combustion air that is supplied to the incinerator 11. The heat medium that passed through the heat exchanger 3 is heated by the methanation apparatus 1. The heat medium that passed through the reactor 101 is heated by heat exchange with the heat generating portion in the reactor 101. The heat medium that passed through the reactor 103 is heated by heat exchange with the heat generating portion in the reactor 103. In the heat exchanger 3, heat exchange is performed between the combustion air that is supplied to the incinerator 11 and the heated heat medium, whereby the combustion air is heated, and the heated combustion air is supplied to the incinerator 11. By supplying the heated combustion air to the incinerator 11, high-temperature air combustion is achieved, and the thermal efficiency of the incineration apparatus 2 is improved. In addition, the heat medium that flows in the heat medium circulation line 41 can also be used to heat hot water or steam in the incineration apparatus 2.

[0043] The jacket portion of the reactor 103 is connected to the heat exchanger 3 through a pipe through which the heat medium flows. The heat medium that passed through the reactor 101, the reactor 103, and the heat exchanger 3 is cooled by the heat medium heat exchanger 106 in the methanation apparatus 1. The heating device 105 is connected to the heat medium heat exchanger 106 through a pipe through which the heat medium flows. In the pipe that connects the heating device 105 and the heat medium heat exchanger 106, a heat medium circulation pump 114 that sends the heat medium that is cooled by the heat medium heat exchanger 106 to the heating device 105 is provided. In addition, a regulating valve 115 and a regulating valve 116 are provided in the pipe through which the heat medium flows. By opening and closing the regulating valve 115 and the regulating valve 116, the heat medium that passed through the reactor 101, the reactor 103, and the heat exchanger 3 can be sent to the heating device 105 via the heat medium heat exchanger 106, or can be sent to the heating device 105 without passing through the heat medium heat exchanger 106. The arrangement of the heat medium heat exchanger 106, the heat medium circulation pump 114, the regulating valve 115, and the regulating valve 116 can also be changed, and the heat medium that is heated by the heating device 105 can pass through the reactor 101 after passing through the heat exchanger 3 and the reactor 103.

[0044] The methanation apparatus 1 includes a cooling tower 117 and a cooling water circulating pump 118. The cooling tower 117 cools the cooling water that has performed heat exchange with the heat medium in the heat medium heat exchanger 106. For example, tap water supplied from outside the system to the cooling tower 117 can be used as the cooling water. The cooling water circulating pump 118 circulates the cooling water supplied to the cooling tower 117 between the heat medium heat exchanger 106 and the cooling tower 117.

[0045] The methanation apparatus 1 includes a cooling tower 119. The cooling tower 119 cools the cooling water (coolant) used to condense the generated water in the gas cooling heat exchanger 102 and the gas cooling heat exchanger 104. The gas cooling heat exchanger 102, the gas cooling heat exchanger 104, and the cooling tower 119 are connected by a pipe through which the cooling water flows. The cooling water cooled by the cooling tower 119 is returned to the cooling tower 119 via the gas cooling heat exchanger 102 and the gas cooling heat exchanger 104. A chiller can be used instead of the cooling tower 119.

[0046] Figure 1 The illustrated heat utilization system includes a steam generator 31 and a condenser 32. In the heat utilization system of the first embodiment, incineration of waste is performed in the incinerator 11, and steam generated in the boiler 19 is sent to the heat exchanger 3, the exhaust gas heater 16, and the steam generator 31. The temperature of the steam generated in the boiler 19 is, for example, 300°C to 450°C. The heat exchanger 3 has an internal pipe through which the steam generated in the boiler 19 passes. In the heat exchanger 3, heat exchange is performed between the combustion air supplied to the incinerator 11 and the steam generated in the boiler 19, whereby heated combustion air is supplied to the incinerator 11. The steam discharged from the heat exchanger 3 is returned to the boiler 19. In the exhaust gas heater 16, the exhaust gas is heated by heat exchange between the steam generated in the boiler 19 and the exhaust gas. The steam discharged from the exhaust gas heater 16 is returned to the boiler 19.

[0047] The steam generator 31 is a power generation section driven by the steam generated in the boiler 19. The steam generator 31 can be a turbine-type generator or a screw-type generator. The steam generator 31 generates power using the steam supplied from the boiler 19. The power generated by the steam generator 31 can be used for in-process power for a control unit for operating the process, a heating apparatus, a compressor, and the like. In addition, the power generated by the steam generator 31 can be used for in-process power, and the remaining power can be supplied to an arbitrary power source or the like. In addition, an electric storage apparatus can be provided, and the power generated by the steam generator 31 can be stored in the electric storage apparatus. The condenser 32 condenses the steam discharged from the steam generator 31. The condensed water condensed by the condenser 32 is returned to the boiler 19.

[0048] According to the heat utilization system of the first embodiment, the combustion air supplied to the incinerator 11 is heated by heat exchange between the heat medium heated by the methanation device 1 and the combustion air supplied to the incinerator 11. By using the heat medium heated by the methanation device 1 and the steam generated in the boiler 19 to heat the combustion air supplied to the incinerator 11, the amount of steam supplied to the preheater 10 can be reduced. In the heat utilization system of the first embodiment, the supply of steam to the preheater 10 can also be stopped. By using the heat medium heated by the methanation device 1 to heat the combustion air supplied to the incinerator 11, the supply of steam to the preheater 10 can be omitted. By reducing or omitting the supply of steam to the preheater 10, the supply of steam to the exhaust gas heater 16 and the steam generator 31 is increased. By increasing the supply of steam to the steam generator 31, the power generation of the steam generator 31 can be increased. It is also possible to keep the supply of steam to the exhaust gas heater 16 constant and increase the supply of steam to the steam generator 31. It is also possible to keep the amount of steam supplied to the steam generator 31 constant, while increasing the amount of steam supplied to the exhaust gas heater 16.

[0049] According to the heat utilization system of the first embodiment, by exchanging heat between the heat medium flowing in the heat medium circulation pipeline 41 and the combustion air supplied to the incinerator 11, the heat generated in the methanation device 1 is supplied to the incineration device 2, and the heat generated in the methanation device 1 can be effectively utilized by the incineration device 2.

[0050] <Second Implementation>

[0051] Reference Figure 2 and Figure 3 The second embodiment will now be described. Furthermore, in the second embodiment, structures identical to those in the first embodiment are labeled with the same symbols, and their descriptions may be omitted. Figure 3 This is a structural diagram of the heat utilization system according to the second embodiment. Figure 3 The heat utilization system shown includes: a methanation unit 1; an incineration unit 2; and a heat exchanger 4, which supplies heat generated in one of the methanation unit 1 and the incineration unit 2 to the other. The heat exchanger 4 is an example of a heat supply unit. Figure 3 In the example shown, heat exchanger 4 is installed in exhaust gas heater 16. The structure of the methanation apparatus 1 in the second embodiment is the same as that in the first embodiment.

[0052] The methanation apparatus 1 has a heat medium circulation line 42 through which a heat medium for adjusting the temperature in the reactors 101 and 103 is circulated. The heat medium is, for example, heat medium oil, water, or steam. The heat medium circulation line 42 has, for example, piping connecting the reactors 101 and 103 and the heat exchanger 4 provided in the exhaust gas heater 16, but can have other structural components. The reaction for generating methane gas is an exothermic reaction, and in the operation of the methanation apparatus 1, the heat medium is circulated by the heat medium circulation line 42 in order to recover the heat in the reactors 101 and 103, so that the temperature in the reactors 101 and 103 does not become excessively high. The heat medium flowing in the heat medium circulation line 42 is circulated in the methanation apparatus 1 and the exhaust gas heater 16. Specifically, the heat medium passes through the reactor 101, then passes through the reactor 103, passes through the heat exchanger 4, and then passes through the reactor 101 again.

[0053] The incineration apparatus 2 includes an incinerator 11, a dust collecting device 12, a supply fan 13, an exhaust gas treatment device 14, a recovery device 15, an exhaust gas heater 16, an induced draft fan 17, and a stack 18. In the present embodiment, the preheater 10 is disposed inside the incineration apparatus 2, but the preheater 10 can be disposed outside the incineration apparatus 2. Figure 3 In the present embodiment, an example in which a portion of the exhaust gas discharged from the dust collecting device 12 is supplied to the incinerator 11 via the supply fan 13 is shown, but the present embodiment is not limited to this example. A portion of the exhaust gas discharged from the exhaust gas treatment device 14 can be supplied to the incinerator 11 via the supply fan 13. In addition, a portion of the exhaust gas discharged from the exhaust gas heater 16 can be supplied to the incinerator 11 via the supply fan 13. A portion of the exhaust gas can not be supplied to the incinerator 11. Figure 3 In the present embodiment, an example in which a portion of the exhaust gas discharged from the dust collecting device 12 is supplied to the incinerator 11 via the supply fan 13 is shown, but the present embodiment is not limited to this example. A portion of the exhaust gas discharged from the exhaust gas treatment device 14 can be supplied to the incinerator 11 via the supply fan 13. In addition, a portion of the exhaust gas discharged from the exhaust gas heater 16 can be supplied to the incinerator 11 via the supply fan 13. A portion of the exhaust gas can not be supplied to the incinerator 11.

[0054] In the heat utilization system of the second embodiment, incineration of waste is performed in the incinerator 11, and the steam generated in the boiler 19 is supplied to the preheater 10 and the steam turbine 31. The temperature of the steam generated in the boiler 19 is, for example, 300°C to 450°C. The steam generated in the boiler 19 is not supplied to the exhaust gas heater 16. As in the first embodiment, the steam generated in the boiler 19 is supplied to the preheater 10 and the steam turbine 31. Figure 2 and Figure 3As shown, the heat medium that passed through the reactor 103 passes through the heat exchanger 4. In the operation of the methanation apparatus 1, the temperature of the heat medium that passed through the reactor 103 is, for example, about 250°C. The heat exchanger 4 has an internal pipe through which the heat medium passes, and an internal pipe through which the exhaust gas passes. In the heat exchanger 4, the internal pipe through which the heat medium passes and the internal pipe through which the exhaust gas passes can also be arranged in such a manner that a part of the internal pipe through which the heat medium passes is adjacent to a part of the internal pipe through which the exhaust gas passes. In the heat exchanger 4, heat exchange is performed between the heat medium that passed through the heat exchanger 4 and the exhaust gas that passed through the heat exchanger 4. Thus, the heat exchanger 4 performs heat exchange between the heat medium that flows in the heat medium circulation line 42 and the exhaust gas that is discharged from the incinerator 11. In addition, the heat medium that flows in the heat medium circulation line 42 can also be used to heat the hot water or steam in the incineration apparatus 2.

[0055] The preheater 10 has an internal pipe through which the steam generated in the boiler 19 passes, and an internal pipe through which the combustion air passes. In the preheater 10, the internal pipe through which the heat medium passes and the internal pipe through which the combustion air passes can also be arranged in such a manner that a part of the internal pipe through which the heat medium passes is adjacent to a part of the internal pipe through which the combustion air passes. The steam that is discharged from the preheater 10 is returned to the boiler 19.

[0056] The heat medium that passed through the heat exchanger 4 is heated by the methanation apparatus 1. The heat medium that passed through the reactor 101 is heated by heat exchange with the heat generating portion in the reactor 101. The heat medium that passed through the reactor 103 is heated by heat exchange with the heat generating portion in the reactor 103. In the heat exchanger 4, heat exchange is performed between the exhaust gas that passed through the heat exchanger 4 and the heated heat medium, whereby the exhaust gas that is delivered to the induced draft fan 17 is heated. By heating the exhaust gas using the exhaust gas heater 16, condensation of the flue through which the exhaust gas flows and whitening of the exhaust gas are suppressed. In addition, in the case where the exhaust gas is subjected to denitration, it is necessary to raise the temperature of the exhaust gas to a temperature suitable for denitration (for example, 170°C). By performing heat exchange between the heat medium that is heated by the methanation apparatus 1 and the exhaust gas, it is possible to raise the temperature of the exhaust gas to a temperature suitable for denitration. In Figure 3In the second embodiment, the example in which all of the exhaust gas discharged from the exhaust gas treatment device 14 flows into the recuperator 15 is shown, but the present application is not limited to the example. A part of the exhaust gas discharged from the exhaust gas treatment device 14 can be sent to the recuperator 15. In this case, the exhaust gas heater 16 can heat the exhaust gas that is not sent to the recuperator 15, or can heat the exhaust gas that has passed through the recuperator 15. Alternatively, the exhaust gas heater 16 can heat both of the exhaust gas that is not sent to the recuperator 15 and the exhaust gas that has passed through the recuperator 15. Further, heat exchange can be performed between the exhaust gas sent to the recuperator 15 and the exhaust gas that has passed through the recuperator 15. In this case, the exhaust gas heater 16 can heat the exhaust gas after the heat exchange between the exhaust gas sent to the recuperator 15 and the exhaust gas that has passed through the recuperator 15.

[0057] In the heat utilization system according to the second embodiment, the exhaust gas heater 16 heats the exhaust gas by performing heat exchange between the exhaust gas that has passed through the heat exchanger 4 and the heat medium that has been heated by the methanation device 1. Therefore, the supply of steam to the exhaust gas heater 16 can be omitted. By omitting the supply of steam to the exhaust gas heater 16, the amount of steam supplied to the preheater 10 and the steam generator 31 can be increased. The amount of steam supplied to the preheater 10 can be constant, and the amount of steam supplied to the steam generator 31 can be increased. The amount of steam supplied to the steam generator 31 can be constant, and the amount of steam supplied to the preheater 10 can be increased. In the heat utilization system according to the second embodiment, steam can be supplied to the exhaust gas heater 16. In this case, the exhaust gas heater 16 heats the exhaust gas by performing heat exchange between the exhaust gas that has passed through the heat exchanger 4 and the heat medium that has been heated by the methanation device 1, and therefore the amount of steam supplied to the exhaust gas heater 16 can be reduced. As a result, the amount of steam supplied to the steam generator 31 is increased, and therefore the amount of power generated by the steam generator 31 can be increased.

[0058] In the heat utilization system according to the second embodiment, the heat generated in the methanation device 1 is supplied to the incineration device 2 by performing heat exchange between the heat medium flowing in the heat medium circulation line 42 and the exhaust gas discharged from the incinerator 11, and therefore the heat generated in the methanation device 1 can be effectively utilized by the incineration device 2.

[0059] <Third Embodiment>

[0060] Reference Signs Figure 2 and Figure 4 The third embodiment will be described. In the third embodiment, the same reference signs are assigned to the same structures as those of the first embodiment, and the description thereof will be appropriately omitted. Figure 4is a configuration diagram of a heat utilization system of the third embodiment. Figure 4 The heat utilization system shown includes a methanation device 1, an incineration device 2, and a heat exchanger 5 that supplies heat generated in one of the methanation device 1 and the incineration device 2 to the other of the methanation device 1 and the incineration device 2. The heat exchanger 5 is an example of a heat supply portion. In Figure 4 In the example shown, the heat exchanger 5 is disposed outside the methanation device 1, but is not limited to this example and can be disposed inside the methanation device 1. In the case where the heat exchanger 5 is disposed inside the methanation device 1, Figure 2 In the case where the heat exchanger 5 is disposed inside the methanation device 1, the heat exchanger 5 can be disposed adjacent to the heating device 105, or the heat exchanger 5 can be disposed instead of the heating device 105.

[0061] The methanation device 1 has a heat medium circulation line 43 that circulates a heat medium for adjusting the temperature inside the reactors 101 and 103. The heat medium is, for example, heat medium oil, water, or steam. The heat medium circulation line 43 has, for example, piping that connects the reactors 101 and 103 and the heat exchanger 5, but can have other structural components. The reaction that generates the methane gas is an exothermic reaction, and in the operation of the methanation device 1, the heat medium is circulated by the heat medium circulation line 43 in order to recover the heat inside the reactors 101 and 103, so that the temperature inside the reactors 101 and 103 does not become excessively high. The heat medium that flows in the heat medium circulation line 42 circulates in the methanation device 1 and the heat exchanger 5. Specifically, the heat medium passes through the reactor 101, then passes through the reactor 103, passes through the heat exchanger 5, and then passes through the reactor 101 again.

[0062] The incineration device 2 includes an incinerator 11, a dust collecting device 12, a blower 13, an exhaust gas treatment device 14, a recuperator 15, an exhaust gas heater 16, an induced draft fan 17, and a chimney 18. In Figure 4 In the example shown, the preheater 10 is disposed inside the incineration device 2, but is not limited to this example and can be disposed outside the incineration device 2. In Figure 4 In the example shown, a portion of the exhaust gas discharged from the dust collecting device 12 is sent to the incinerator 11 via the blower 13, but is not limited to this example. A portion of the exhaust gas discharged from the exhaust gas treatment device 14 can also be sent to the incinerator 11 via the blower 13. In addition, a portion of the exhaust gas discharged from the exhaust gas heater 16 can also be sent to the incinerator 11 via the blower 13.

[0063] In the heat utilization system of the third embodiment, incineration of waste is performed in the incinerator 11, and the steam generated in the boiler 19 is sent to the heat exchanger 5, the preheater 10, the exhaust gas heater 16, and the steam power generator 31. The temperature of the steam generated in the boiler 19 is, for example, 300 to 450°C. As shown in FIG. 1, the steam generated in the boiler 19 is sent to the heat exchanger 5, the preheater 10, the exhaust gas heater 16, and the steam power generator 31 in this order. The steam generated in the boiler 19 is sent to the heat exchanger 5, the preheater 10, the exhaust gas heater 16, and the steam power generator 31 in this order. Figure 2 and Figure 4 As shown in FIG. 1, the heat medium that has passed through the reactor 103 passes through the heat exchanger 5. The heat exchanger 5 has an internal pipe through which the heat medium passes and an internal pipe through which the steam generated in the boiler 19 passes. In the heat exchanger 5, the internal pipe through which the heat medium passes and the internal pipe through which the steam passes can be arranged so that a part of the internal pipe through which the heat medium passes is adjacent to a part of the internal pipe through which the steam passes. In the heat exchanger 5, heat exchange is performed between the heat medium that has passed through the heat exchanger 5 and the steam that has passed through the heat exchanger 5. Thus, the heat exchanger 5 performs heat exchange between the heat medium flowing in the heat medium circulation line 43 and the steam generated in the boiler 19. The steam discharged from the heat exchanger 5 is returned to the boiler 19.

[0064] The preheater 10 has an internal pipe through which the steam generated in the boiler 19 passes and an internal pipe through which combustion air passes. In the preheater 10, the internal pipe through which the steam passes and the internal pipe through which the combustion air passes can be arranged so that a part of the internal pipe through which the steam passes is adjacent to a part of the internal pipe through which the combustion air passes. The steam discharged from the preheater 10 is returned to the boiler 19.

[0065] At the start of the methanation apparatus 1 (at the start of operation), the temperature of the heat medium flowing in the heat medium circulation line 43 is low. At the start of the methanation apparatus 1, the heat medium flowing in the heat medium circulation line 43 is heated using the steam generated in the boiler 19, and then the heat medium is supplied to the methanation apparatus 1. The heat medium that has been heated and warmed up passes through the reactor 101, and the reactor 101 is warmed up. Thus, the catalyst in the reactor 101 is heated to a reaction start temperature. The heat medium that has passed through the reactor 101 is sent to the jacket portion of the reactor 103, and passes through the reactor 103. The heat medium that has been heated and warmed up passes through the reactor 103, and the reactor 103 is warmed up. Thus, the catalyst in the reactor 103 is heated to a reaction start temperature.

[0066] According to the heat utilization system of the third embodiment, the heated heat medium passes through the reactors 101 and 103 by heat exchange between the heat medium flowing in the heat medium circulation line 43 and the steam generated in the boiler 19. Therefore, in the case where the heat medium is heated by the heating device 105 at the start of the methanation apparatus 1, the amount of electric power supplied to the heating device 105 (electric power used for the heating device) can be reduced. Even in the case where the heating device 105 is operated in order to maintain the temperature of the heat medium at the time of temporary stop of the methanation apparatus 1 or reduction of the operation load of the methanation apparatus 1, the amount of electric power supplied to the heating device 105 can be reduced. In addition, in the case where heating of the heat medium by the heating device 105 is not required, the heating device 105 can be omitted, and supply of electric power to the heating device 105 or maintenance of the heating device 105 is not required.

[0067] According to the heat utilization system of the third embodiment, the heated heat medium passes through the reactors 101 and 103 by heat exchange between the heat medium flowing in the heat medium circulation line 43 and the steam generated in the boiler 19 possessed by the incineration apparatus 2, and the heat generated in the incineration apparatus 2 is supplied to the methanation apparatus 1, so that the heat generated in the incineration apparatus 2 can be effectively utilized by the methanation apparatus 1.

[0068] In addition, each of the processes and the steps described above can be understood as a heat supply method in the heat utilization system, a control method of the heat utilization system, or the like. Each of the processes and the steps described above in the methanation apparatus 1 can be understood as a product gas generation method in the methanation apparatus 1, an operation method of the methanation apparatus 1, or the like. Each of the processes and the steps described above in the incineration apparatus 2 can be understood as an incineration method in the incineration apparatus 2, an operation method of the incineration apparatus 2, or the like. It can also be understood as a control system, a generation system, an operation system, or the like having at least a part of each of the processes and the functions described above. Furthermore, each of the means and the processes can be combined with each other as much as possible to constitute the present application. Each of the embodiments can be combined with each other.

[0069] Furthermore, in the first to third embodiments, the incineration apparatus 2 is described as having the boiler 19, but in the case where the heat generated in the methanation apparatus 1 is supplied to the incineration apparatus 2, the incineration apparatus 2 can also be an apparatus not having the boiler 19, such as a water injection furnace.

[0070] Explanation of Reference Numerals

[0071] 1: Methanation apparatus

[0072] 2: Incineration apparatus

[0073] 3, 4, 5: Heat exchanger

[0074] 10: Preheater

[0075] 11: Incineration furnace

[0076] 12: dust collecting device

[0077] 13: air supply fan

[0078] 14: exhaust gas treatment device

[0079] 15: recycler

[0080] 16: exhaust gas heater

[0081] 17: induced draft fan

[0082] 18: chimney

[0083] 19: boiler

[0084] 20: absorption tower

[0085] 21: regenerator

[0086] 31: steam generator

[0087] 32: condenser

[0088] 41, 42, 43: medium circulation line

[0089] 101, 103: reactor

Claims

1. A heat utilization system, comprising: Methanation equipment produces methane from hydrogen and carbon dioxide; Incineration equipment, including an incinerator; as well as The heat supply unit supplies heat generated in one of the methanation equipment and the incineration equipment to the other of the methanation equipment and the incineration equipment.

2. The heat utilization system according to claim 1, wherein The methanation equipment includes: a reactor for reacting hydrogen with carbon dioxide to produce methane; and a heat medium circulation pipeline for circulating a heat medium used to regulate the temperature within the reactor. The heat supply unit is a heat exchanger that performs heat exchange between the heat medium flowing in the heat medium circulation pipeline and the combustion air supplied to the incinerator.

3. The heat utilization system according to claim 2, wherein... The heat exchanger is installed in a preheater that preheats the combustion air supplied to the incinerator.

4. The heat utilization system according to claim 1, wherein... The methanation equipment includes: a reactor for reacting hydrogen with carbon dioxide to produce methane; and a heat medium circulation pipeline for circulating a heat medium used to regulate the temperature within the reactor. The heat supply unit is a heat exchanger that performs heat exchange between the heat medium flowing in the heat medium circulation pipeline and the exhaust gas discharged from the incinerator.

5. The heat utilization system according to claim 4, wherein The heat exchanger is installed in an exhaust gas heater that heats the exhaust gas discharged from the incinerator.

6. The heat utilization system according to claim 1, wherein The methanation equipment includes: a reactor for reacting hydrogen with carbon dioxide to produce methane; and a heat medium circulation pipeline for circulating a heat medium used to regulate the temperature within the reactor. The heat supply unit is a heat exchanger that performs heat exchange between the heat medium flowing in the heat medium circulation pipeline and the steam generated in the boiler of the incineration equipment.

7. The heat utilization system according to any one of claims 2 to 6, wherein The incineration equipment includes a recoverer for recovering the carbon dioxide from the exhaust gas discharged from the incinerator. The carbon dioxide recovered by the recycler is fed together with the hydrogen into the reactor.

8. A heat supply method, for a heat utilization system. The heat utilization system includes: Methanation equipment produces methane from hydrogen and carbon dioxide; as well as Incineration equipment, including an incinerator, The heat supply method supplies heat generated in one of the methanation equipment and the incineration equipment to the other of the methanation equipment and the incineration equipment.

Images