WO2019176745A1 - Methane production device and method - Google Patents

Methane production device and method Download PDF

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Publication number
WO2019176745A1
WO2019176745A1 PCT/JP2019/009164 JP2019009164W WO2019176745A1 WO 2019176745 A1 WO2019176745 A1 WO 2019176745A1 JP 2019009164 W JP2019009164 W JP 2019009164W WO 2019176745 A1 WO2019176745 A1 WO 2019176745A1
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WIPO (PCT)
Prior art keywords
gas
methane
product gas
line
hydrogen
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PCT/JP2019/009164
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French (fr)
Japanese (ja)
Inventor
雅典 岩城
藍 西山
友祐 藁谷
学 政本
Original Assignee
川崎重工業株式会社
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Priority to DE112019001261.4T priority Critical patent/DE112019001261T5/en
Publication of WO2019176745A1 publication Critical patent/WO2019176745A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/50—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification
    • C01B3/501—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification by diffusion
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
    • C07C1/02—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon
    • C07C1/12—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon from carbon dioxide with hydrogen
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C7/00—Purification; Separation; Use of additives
    • C07C7/144—Purification; Separation; Use of additives using membranes, e.g. selective permeation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2256/00—Main component in the product gas stream after treatment
    • B01D2256/24—Hydrocarbons
    • B01D2256/245—Methane
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/10—Single element gases other than halogens
    • B01D2257/108—Hydrogen
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/06—Integration with other chemical processes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/582—Recycling of unreacted starting or intermediate materials

Definitions

  • the present invention relates to a methane production apparatus and method for producing methane by supplying hydrogen to a raw material gas containing carbon dioxide.
  • Patent Documents 1 and 2 propose a methane production apparatus that suppresses a temperature rise in the reactor.
  • the methanation reactor of Patent Document 1 includes a first reactor for supplying a raw material gas and a part of hydrogen, a second reactor for supplying the remainder of hydrogen to the gas discharged from the first reactor, and a second reaction.
  • a third reactor for adjusting the composition of the gas exiting the reactor. The reaction temperature of the first reactor is adjusted by the amount of hydrogen supplied to the first reactor.
  • the methane production apparatus of Patent Document 2 communicates a plurality of reactors in which a catalyst is accommodated with two adjacent reactors, and sends the product gas generated in the former reactor to the latter reactor.
  • a plurality of communication lines, a raw material gas introduction part that introduces steam together with the raw material gas into the first reactor among the plurality of reactors, and a methanation of the product gas generated in the first reactor in each communication line A cooling unit that cools to a temperature at which the reaction starts.
  • JP 2013-136538 A Japanese Patent Laying-Open No. 2015-107943
  • a relatively high methane concentration is required for the product gas produced by the methane production equipment.
  • the methane concentration of the product gas emitted from the reactor may vary.
  • methane is separated from the product gas exiting the final-stage reactor in an adsorption tower, and the separated methane is recovered as product gas. Therefore, the methane concentration of the product gas is stabilized at a high value.
  • the apparatus for separating methane from the product gas is relatively expensive and complicated to maintain, there is also a demand to omit it from the methane production apparatus.
  • the present invention has been made in view of the above circumstances, and an object thereof is to provide a methane production apparatus and method for producing methane, which is a product gas, from a raw material gas containing mixed hydrogen and carbon dioxide.
  • the purpose is to propose a technology that can control the methane concentration of the product gas even if the device for separating the gas is omitted.
  • a methane production apparatus is a methane production apparatus that produces methane, which is a product gas, from a raw material gas containing mixed hydrogen and carbon dioxide, A reactor containing a methanation catalyst; A source gas supply line for supplying the source gas to the reactor; A quality control device, A product gas line connecting the reactor and the quality control device, and sending the product gas from the reactor to the quality control device; A product gas tank for storing the product gas; A product gas line for connecting the quality control device and the product gas tank, and sending the product gas from the quality control device to the product gas tank; An off-gas line connected to the quality control device,
  • the quality control device includes a methane concentration meter that detects a methane concentration of the product gas, a flow channel switch that switches a flow channel connected to the product gas line between the product gas line and the off-gas line, The generated gas line and the product gas line are connected when the detected methane concentration is equal to or higher than a predetermined concentration, and when the detected methane
  • a downstream end of the off-gas line may be connected to the source gas supply line.
  • the product gas that has not been recovered as a product is reused as a raw material. Therefore, resources can be used effectively, and the atmospheric emission of product gas containing methane and carbon dioxide, which are greenhouse gases, can be reduced.
  • the quality control apparatus may include a plurality of off-gas containers connected in parallel to the product gas line, and store a gas having a methane concentration less than the predetermined concentration in the plurality of off-gas containers.
  • the production gas that is, off gas
  • the off gas discharge timing and the discharge amount can be controlled.
  • the methane production apparatus further includes a hydrogen separation device provided in the product gas line, and the hydrogen separation device passes a hydrogen permeable membrane and the methane provided on one side through the hydrogen permeable membrane.
  • a methane flow path and a carbon dioxide flow path through which the carbon dioxide before being mixed with the hydrogen provided on the other side through the hydrogen permeable membrane may be provided.
  • the methane production apparatus includes a temperature sensor for detecting the temperature of the catalyst in the foremost reactor, a buffer tank provided in the source gas supply line, and a hydrogen supply line for supplying the hydrogen to the buffer tank And a carbon dioxide supply line for supplying the carbon dioxide to the buffer tank, a release valve provided in the carbon dioxide supply line, and a temperature of the catalyst detected based on the detected temperature of the catalyst. At least a part of the carbon dioxide passing through the carbon dioxide supply line is released out of the system at the above time, and the release valve is closed when the temperature of the catalyst is lower than the predetermined temperature.
  • a discharge valve control device to be operated may be further provided.
  • the methanation in the reactor is reduced by reducing the proportion of carbon dioxide in the raw material gas.
  • the reaction can be suppressed and the temperature of the methanation catalyst can be lowered.
  • a method for producing methane includes: A step of preparing a raw material gas by mixing hydrogen and carbon dioxide; Reacting the hydrogen and the carbon dioxide in the source gas in the presence of a methanation catalyst to produce methane and water; Detecting the methane concentration of the produced gas containing the produced methane and water and the unreacted raw material gas; When the detected methane concentration of the generated gas is equal to or higher than a predetermined concentration, the generated gas is sent to a product gas tank, and when the detected methane concentration of the generated gas is lower than the predetermined concentration, the generated gas is sent to an off-gas line. And a process.
  • the step of sending the generated gas to the off-gas line may include mixing the generated gas into the raw material gas.
  • the product gas that has not been recovered as a product is reused as a raw material. Therefore, resources can be used effectively, and the atmospheric emission of product gas containing methane and carbon dioxide, which are greenhouse gases, can be reduced.
  • the step of sending the product gas to the off-gas line may include sending the product gas to a plurality of gas containers.
  • the product gas that has not been recovered as a product is temporarily stored in a plurality of gas containers, whereby the discharge timing and the discharge amount of the product gas can be controlled.
  • the step of sending the product gas to the product gas tank uses a hydrogen partial pressure difference between the methane separated from the product gas and the carbon dioxide before being mixed with the hydrogen, to transmit hydrogen. Removing a hydrogen contained therein from the methane using a membrane may be included.
  • the methane concentration of the product gas is controlled even if the apparatus for separating methane from the product gas is omitted. can do.
  • FIG. 1 is a diagram showing an overall configuration of a methane production apparatus according to an embodiment of the present invention.
  • FIG. 2 is a diagram showing the configuration of the hydrogen separator.
  • FIG. 3 is a diagram showing the configuration of the quality management apparatus.
  • FIG. 4 is a diagram showing a flow of processing of the quality management apparatus.
  • FIG. 5 is a diagram illustrating a configuration of a quality control apparatus for a methane production apparatus according to the first modification.
  • FIG. 6 is a diagram illustrating a configuration of a quality control apparatus for a methane production apparatus according to Modification 2.
  • the methane production apparatus produces methane from a raw material gas containing mixed hydrogen and carbon dioxide.
  • FIG. 1 is a diagram showing an overall configuration of a methane production apparatus 100 according to an embodiment of the present invention.
  • a methane production apparatus 100 shown in FIG. 1 supplies a raw material gas to a plurality of reactors R1, R2,... Connected in series through a communication line 1 and to the foremost reactor R1 among the plurality of reactors R.
  • a gas tank 4 a product gas line 40 connecting the quality control device 9 and the product gas tank 4, and an off-gas line 80 connected to the quality control device 9 are provided.
  • the methane production apparatus 100 includes two reactors R, a first reactor R1 and a second reactor R2. However, the number of reactors R may be three or more.
  • Each reactor R contains a methanation catalyst that promotes a methanation reaction that produces methane and water from hydrogen and carbon dioxide.
  • the methanation catalyst is not particularly limited, and may be a commercially available Ni-based catalyst, for example.
  • the reactors R1 and R2 are provided with temperature sensors T1 and T2 for detecting the temperature of the methanation catalyst.
  • the first reactor R1 and the second reactor R2 are connected by a communication line 1, and the product gas discharged from the first reactor R1 flows into the second reactor R2 through the communication line 1.
  • the product gas contains unreacted carbon dioxide and hydrogen in addition to methane and water produced by the methanation reaction.
  • the number of communication lines 1 is 1, but the methane production apparatus 100 includes the number of communication lines 1 corresponding to the number of reactors R.
  • the communication line 1 is provided with a first heat exchanger 11, a water separator 12, and a second heat exchanger 13.
  • first heat exchanger 11 heat exchange between the generated gas and the cooling water is performed.
  • water separator 12 the moisture in the product gas condensed by being cooled by the first heat exchanger 11 is separated from the product gas.
  • second heat exchanger 13 heat exchange is performed between the hot oil used for cooling the reactor R2 and the product gas.
  • the temperature of the product gas flowing from the communication line 1 into the next stage reactor (second reactor R2) by the first heat exchanger 11 and the second heat exchanger 13 is equal to or higher than the temperature at which the methanation reaction starts. The temperature is adjusted to below the temperature at which the nation reaction stops.
  • a buffer tank 21 that stores the raw material gas
  • a compressor 22 that compresses the raw material gas discharged from the buffer tank 21, and the compressed raw material gas are adjusted to a temperature suitable for the methanation reaction.
  • a heat exchanger 23 is provided.
  • the buffer tank 21 is supplied with hydrogen from the hydrogen supply line 24 and supplied with carbon dioxide from the carbon dioxide supply line 25.
  • the carbon dioxide supply line 25 is provided with a discharge valve 26 controlled by a discharge valve control device 27.
  • the release valve control device 27 Based on the temperature of the methanation catalyst of the first reactor R1 detected by the temperature sensor T1, the release valve control device 27 is configured to output at least carbon dioxide passing through the carbon dioxide supply line 25 when the temperature of the catalyst is equal to or higher than a predetermined temperature.
  • the release valve 26 is operated so that the release valve 26 is closed when a part is released out of the system and the temperature of the catalyst is lower than a predetermined temperature.
  • the raw material gas is compressed so as to have a pressure suitable for the methanation reaction.
  • the pressure suitable for the methanation reaction varies depending on the type of methanation catalyst and the specifications of the reactor R.
  • the pressure condition of the raw material gas flowing into the first reactor R1 is, for example, 0 to 3 MPa in absolute pressure.
  • heat exchanger 23 heat exchange between the hot oil used for cooling the first reactor R1 and the raw material gas is performed, and the raw material gas is adjusted to a temperature suitable for the methanation reaction.
  • the temperature suitable for the methanation reaction varies depending on the type of methanation catalyst and the number of stages of the reactor R.
  • the raw material gas flowing into the first reactor R1 is about 250 to 350 ° C.
  • the reaction gas flowing into the second reactor R2 is about 150 to 250 ° C.
  • the product gas that has exited from the last-stage reactor R2 is sent to the quality control device 9 through the product gas line 30.
  • the product gas line 30 is provided with a heat exchanger 31 and a water separator 32.
  • heat exchanger 31 heat is exchanged between the product gas that has come out of the final-stage reactor R2 and water.
  • water separator 32 the moisture in the product gas condensed by being cooled by the heat exchanger 31 is separated.
  • the quality control device 9 is connected to the product gas tank 4 via the product gas line 40.
  • the quality control device 9 is connected to the raw material gas supply line 2 via the off gas line 80.
  • the quality control device 9 switches the flow path connected to the product gas line 30 between the product gas line 40 and the off gas line 80 based on the methane concentration of the product gas.
  • the quality management device 9 will be described in detail later.
  • the downstream end of the off gas line 80 is connected to the upstream side of the compressor 22 of the raw material gas supply line 2.
  • the downstream end of the off gas line 80 is connected to the buffer tank 21.
  • the downstream end of the off gas line 80 is connected to the downstream side of the buffer tank 21 of the raw material gas supply line 2 and the upstream side of the compressor 22 or the upstream side of the buffer tank 21 of the raw material gas supply line 2. May be.
  • the product gas line 40 is provided with a hydrogen separator 42 for separating hydrogen from the product gas.
  • a hydrogen separator 42 for separating hydrogen from the product gas.
  • FIG. 2 is a diagram showing the configuration of the hydrogen separator 42.
  • 2 includes a hydrogen permeable membrane 71 that allows only hydrogen to pass through, a methane channel 72 provided on one side via the hydrogen permeable membrane 71, and a hydrogen permeable membrane 71 on the other side via the hydrogen permeable membrane 71.
  • a carbon dioxide channel 73 provided.
  • Methane emitted from the methane separator 3 passes through the methane flow path 72.
  • carbon dioxide in the carbon dioxide supply line 25, that is, carbon dioxide before being mixed with hydrogen passes through the carbon dioxide flow path 73.
  • the flow of methane in the methane flow path 72 and the flow of carbon dioxide in the carbon dioxide flow path 73 are opposed to each other.
  • the hydrogen partial pressure of the gas flowing through the carbon dioxide channel 73 is 0, and the hydrogen partial pressure of the gas flowing through the methane channel 72 is greater than 0 (for example, 10,000 Pa).
  • hydrogen in the gas flowing through the methane passage 72 passes through the hydrogen permeable membrane 71 and moves to the carbon dioxide passage 73.
  • hydrogen supplied from the hydrogen supply line 24 and carbon dioxide supplied from the carbon dioxide supply line 25 are mixed at a predetermined ratio to prepare a raw material gas.
  • the raw material gas flows into the first reactor R1 through the compressor 22 and the heat exchanger 23.
  • hydrogen and carbon dioxide in the raw material gas undergo a methanation reaction in the presence of a methanation catalyst to produce methane and water.
  • Methane and water produced in the first reactor R1 and product gas containing unreacted hydrogen and carbon dioxide flow out to the communication line 1.
  • the product gas flowing out to the communication line 1 flows into the second reactor R2 through the first heat exchanger 11, the water separator 12, and the second heat exchanger 13.
  • hydrogen and carbon dioxide in the product gas undergo a methanation reaction in the presence of a methanation catalyst to produce methane and water.
  • Methane and water produced in the second reactor R2 and product gas containing unreacted hydrogen and carbon dioxide flow out to the product gas line 30.
  • the product gas that has flowed out to the product gas line 30 flows into the quality control device 9 through the heat exchanger 31 and the water separator 32.
  • the quality control device 9 sends a product gas having a methane concentration equal to or higher than a predetermined concentration to the product gas line 40.
  • the product gas that flows into the product gas line 40 (that is, product gas) flows into the product gas tank 4 and is recovered as product gas.
  • the quality control device 9 sends a product gas having a methane concentration less than a predetermined concentration to the product gas line 30 or stores it in off-gas containers P1 to PN described later.
  • FIG. 3 is a diagram showing the configuration of the quality management apparatus.
  • the quality control device 9 includes a methane concentration meter 91, a plurality of gas containers P0 to PN (N is a natural number of 1 or more) connected to the product gas line 30, and each gas container P0 to PN.
  • Inlet valves K0 to KN provided at the inlet of the gas
  • outlet valves J0 to JN provided at the outlets of the gas containers P0 to PN
  • pressure gauges V0 to VN provided to the gas containers P0 to PN
  • the plurality of gas containers P0 to PN include at least one product gas container P0 and at least one offgas container P1 to PN.
  • the product gas container P0 temporarily stores a generated gas having a methane concentration equal to or higher than a predetermined concentration.
  • the predetermined concentration is an arbitrary methane concentration, for example, a number of 90% or more.
  • the inlet of the product gas container P 0 is connected to the product gas line 30, and the outlet of the product gas container P 0 is connected to the product gas line 40.
  • a purge line 94 is connected to the product gas container P 0, and a purge valve 95 is provided in the purge line 94.
  • This purge valve 95 and the above-described inlet valves K0 to KN and outlet valves J0 to JN switch the flow path connected to the product gas line 30 between the product gas line 40 and the off gas line 80. Function as.
  • the off-gas containers P1 to PN temporarily store generated gas having a methane concentration lower than a predetermined concentration.
  • the inlets of the off gas containers P1 to PN are connected to the product gas line 30, and the outlets of the off gas containers P1 to PN are connected to the off gas line 80. That is, the plurality of offgas containers P1 to PN are connected in parallel to the product gas line 30, and the plurality of offgas containers P1 to PN are connected to the offgas line 80 in parallel.
  • the methane concentration meter 91 is provided downstream from the water separator 32 and upstream from each quality control device 9.
  • the methane concentration detected by the methane concentration meter 91 is output to the controller 93.
  • the pressures in the gas containers P0 to PN detected by the pressure gauges V0 to VN are output to the controller 93.
  • the controller 93 acquires the methane concentration from the methane concentration meter 91, acquires the pressure from each of the pressure gauges V0 to VN, and based on these values, the flow path switch (inlet valve K0 to KN, outlet valve J0 to JN, And the operation of the purge valve 95).
  • the controller 93 is composed of a computer including a processor and a memory, and has a function as a controller 93 described later by executing a predetermined program by the processor.
  • FIG. 4 is a diagram showing the flow of processing of the quality management device 9.
  • the counter value is n (n is a natural number between 1 and N).
  • the inlet valves K1 to KN and outlet valves J1 to JN of the offgas containers P1 to PN are closed, and the purge valve 95 is closed (step). S1).
  • the reaction gas exiting from the final-stage reactor R2 flows into the product gas container P0 through the heat exchanger 31 and the water separator 32, and further from the product gas container P0 through the product gas line 40 to the product gas tank. Flows into 4.
  • the controller 93 constantly monitors the methane concentration detected by the methane concentration meter 91. If the detected methane concentration is equal to or higher than the predetermined concentration (YES in step S2), the controller 93 returns to step S1 and continues the process. On the other hand, if the detected methane concentration is less than the predetermined concentration (NO in S2), the controller 93 proceeds to step S3.
  • step S3 the controller 93 closes the inlet valve K0 and outlet valve J0 of the product gas container P0, opens the inlet valve Kn of the offgas container Pn, closes the outlet valve Jn of the offgas container Pn, and turns off the offgas container Pn.
  • the flow path switch is operated so that the inlet valves K1 to KN and the outlet valves J1 to JN of the off-gas containers P1 to PN are closed.
  • the reaction gas exiting from the final reactor R2 flows into the offgas container Pn via the heat exchanger 31 and the water separator 32, and is stored in the offgas container Pn. Further, the reaction gas (product gas) flows into the product gas tank 4 through the product gas line 40 from the product gas container P0.
  • the controller 93 compares the pressure in the off-gas container Pn with a predetermined pressure.
  • the controller 93 opens the purge valve 95, opens the inlet valve K0 of the product gas container P0, and outputs the outlet valve J0 of the product gas container P0. Is closed, and the flow path switching device is operated so that the inlet valves K1 to KN and the outlet valves J1 to JN of the off gas containers P1 to PN are closed (step S7). As a result, the product gas exiting the final-stage reactor R2 flows into the product gas container P0 and flows out to the off-gas line 80 through the purge line 94.
  • the product gas line 30 on the downstream side of the methane concentration meter 91 and the product gas container P0 in which the product gas having a methane concentration less than the predetermined concentration may flow in have a methane concentration equal to or higher than the predetermined concentration. Purge with product gas.
  • step S8 When the predetermined purge processing time has elapsed (YES in step S8), the process returns to step S1, and the controller 93 opens the inlet valve K0 and outlet valve J0 of the product gas container P0, and the offgas containers P1 to PN.
  • the flow path switch is operated so that the inlet valves K1 to KN and the outlet valves J1 to JN are closed and the purge valve 95 is closed.
  • the off gas stored in the off gas containers P1 to PN as described above may be used to suppress the thermal runaway of the reactor R.
  • the controller 93 at least one outlet valve of the offgas containers P1 to PN when the temperature of the catalyst is equal to or higher than a predetermined temperature. Open J1-JN.
  • the off-gas flowing out to the off-gas line 80 is mixed into the source gas flowing through the source gas supply line 2.
  • the operation of the methane production apparatus 100 may be stopped.
  • the methane production apparatus 100 of the present embodiment includes the reactor R in which the methanation catalyst is accommodated, the source gas supply line 2 that supplies the source gas to the reactor R, and the quality control apparatus 9.
  • the reactor R and the quality control device 9 are connected, the product gas line 30 for sending the product gas from the reactor R to the quality control device 9, the product gas tank 4 for storing the product gas, the quality control device 9 and the product
  • the product gas line 40 which connects the gas tank 4 and sends the product gas emitted from the quality control device 9 to the product gas tank 4 and the off gas line 80 connected to the quality control device 9 are provided.
  • the quality control device 9 includes a methane concentration meter 91 that detects the methane concentration of the product gas, and a flow path switch (inlet) that switches the flow path connected to the product gas line 30 between the product gas line 40 and the off-gas line 80.
  • Valve K0 to KN, outlet valve J0 to JN) and the product gas line 30 and the product gas line 40 are connected when the detected methane concentration is equal to or higher than the predetermined concentration, and when the detected methane concentration is lower than the predetermined concentration
  • a controller 93 that operates the flow path switch so that the product gas line 30 and the off-gas line 80 are connected to each other.
  • the reactor R includes a plurality of reactors R1 and R2 connected in series by the communication line 1, but the reactor R may be singular.
  • the method for producing methane includes a step of preparing a raw material gas by mixing hydrogen and carbon dioxide, and reacting hydrogen and carbon dioxide in the raw material gas in the presence of a methanation catalyst. And a step of generating water, a step of detecting the generated methane and water, and a step of detecting the methane concentration of the generated gas including the unreacted raw material gas, and when the detected methane concentration of the generated gas is equal to or higher than a predetermined concentration. Sending the gas to the product gas tank 4 and sending the produced gas to the off-gas line 80 when the detected methane concentration of the produced gas is less than a predetermined concentration.
  • the methane production apparatus 100 and method according to the present embodiment only the product gas having a methane concentration equal to or higher than the predetermined concentration is sent to the product gas tank 4, so that the methane concentration of the product gas to be recovered can be controlled. Even if a device for separating methane from the product gas is omitted, methane having high purity can be recovered.
  • the downstream end of the off-gas line 80 is connected to the raw material gas supply line 2.
  • the step of sending the generated gas to the off-gas line 80 includes mixing the generated gas into the raw material gas.
  • the product gas that has not been recovered as a product is reused as a raw material. Therefore, resources can be used effectively, and the atmospheric emission of product gas containing methane and carbon dioxide, which are greenhouse gases, can be reduced.
  • the quality control apparatus 9 includes a plurality of off-gas containers P1 to PN connected in parallel to the product gas line 30, and the methane concentration in the plurality of off-gas containers P1 to PN.
  • a gas having a concentration lower than a predetermined concentration that is, off-gas is stored.
  • the step of sending the product gas to the off-gas line 80 includes sending the product gas to a plurality of gas containers P1 to PN.
  • the production gas that is, off gas
  • the production gas that is, off gas
  • the off gas discharge timing and the discharge amount can be controlled.
  • the methane production apparatus 100 further includes a hydrogen separator 42 provided in the product gas line 40.
  • This hydrogen separator 42 includes a hydrogen permeable membrane 71, a methane passage 72 through which methane is provided on one side via the hydrogen permeable membrane 71, hydrogen provided on the other side via the hydrogen permeable membrane 71, And a carbon dioxide channel 73 through which carbon dioxide before being mixed passes.
  • the step of sending the product gas to the product gas tank 4 utilizes the hydrogen partial pressure difference between methane separated from the product gas and carbon dioxide before being mixed with hydrogen, This includes removing hydrogen contained in methane from the methane using the hydrogen permeable membrane 71.
  • the temperature sensor T1 that detects the temperature of the catalyst in the foremost reactor R1, and the buffer tank 21 provided in the source gas supply line 2 and the buffer tank 21 are supplied with hydrogen.
  • the hydrogen supply line 24 for supplying the carbon dioxide the carbon dioxide supply line 25 for supplying carbon dioxide to the buffer tank 21, the release valve 26 provided in the carbon dioxide supply line 25, and the detected temperature of the catalyst, Release so that at least part of the carbon dioxide passing through the carbon dioxide supply line 25 is released out of the system when the temperature of the catalyst is equal to or higher than the predetermined temperature, and the release valve 26 is closed when the temperature of the catalyst is lower than the predetermined temperature.
  • a discharge valve control device 27 for operating the valve 26 is further provided.
  • FIG. 5 is a diagram illustrating a configuration of the quality control device 9A of the methane production apparatus 100 according to the first modification. As shown in FIG. 5, in the methane production apparatus 100 according to the first modification, the configuration of the quality management apparatus 9A is changed from the quality management apparatus 9 according to the above-described embodiment.
  • the quality control device 9A includes a methane concentration meter 91, a plurality of off-gas containers P1 to PN (N is a natural number of 1 or more) connected to the product gas line 30, and inlets provided at the inlets of the off-gas containers P1 to PN.
  • the valves K1 to KN, outlet valves J1 to JN provided at the outlets of the off-gas containers P1 to PN, pressure gauges V1 to VN provided to the gas containers P1 to PN, and the generated gas line 30 were connected.
  • An on-off valve 99 and a controller 93 are included.
  • the product gas container P0, the product gas container P0 inlet valve K0, the product gas container P0 outlet valve J0, the purge valve 95, and the purge line 94 of the quality control apparatus 9 according to the above-described embodiment are omitted.
  • an on-off valve 99 is provided instead.
  • the on-off valve 99 is connected to the generated gas line 30 in parallel with the plurality of off-gas containers P1 to PN.
  • the on-off valve 99 is connected to the product gas line 40.
  • the controller 93 opens the on-off valve 99 when the product gas line 30 and the product gas line 40 are connected in the processing flow of the quality control device 9 described above, and the product gas line 30 and the off-gas line 80 are connected.
  • the flow switching device open / close valve 99, inlet valves K1 to KN, outlet valves J1 to JN
  • FIG. 6 is a diagram illustrating a configuration of a quality control device 9B of the methane production apparatus 100 according to the second modification. As shown in FIG. 6, in the methane production apparatus 100 according to the second modification, the configuration of the quality management apparatus 9B is changed from the quality management apparatus 9 according to the above-described embodiment.
  • the quality control device 9B includes a methane concentration meter 91, a three-way valve 97 connected to the product gas line 30, a three-way valve 97, and a controller 93.
  • the plurality of gas containers P0 to PN, the inlet valves K0 to KN provided at the inlets of the gas containers P0 to PN, and the gas containers P0 to PN of the quality control apparatus 9 according to the embodiment described above.
  • the outlet valves J0 to JN provided at the outlet, the pressure gauges V0 to VN provided in the gas containers P0 to PN, the purge valve 95, and the purge line 94 are omitted, and a three-way valve 97 is provided instead. It has been.
  • the three-way valve 97 is connected to the product gas line 30, the product gas line 40, and the off gas line 80, and switches the flow path connected to the product gas line 30 between the product gas line 40 and the off gas line 80.
  • the controller 93 operates the three-way valve 97 so that the product gas line 30 and the product gas line 40 are connected when the product gas line 30 and the product gas line 40 are connected in the processing flow of the quality control device 9 described above. And the off-gas line 80 are connected, the three-way valve 97 is operated so that they are connected.

Abstract

This methane production device involves: a step for mixing hydrogen and carbon dioxide to prepare a raw material gas; a step for reacting the hydrogen and carbon dioxide in the raw material gas in the presence of a methanation catalyst to produce methane and water; a step for detecting the methane concentration of the product gas, which contains the generated methane and water and the unreacted raw material gas; and a step for sending the product gas to a product gas tank when the detected methane concentration of the product gas is greater than or equal to a prescribed concentration, and sending the product gas to an off-gas line when the detected methane concentration of the product gas is less than the prescribed concentration.

Description

メタン製造装置及び方法Methane production apparatus and method
　本発明は、二酸化炭素を含有する原料ガスに水素を供給し、メタンを生成するメタン製造装置及び方法に関する。 The present invention relates to a methane production apparatus and method for producing methane by supplying hydrogen to a raw material gas containing carbon dioxide.
　従来、二酸化炭素（ＣＯ２）と水素（Ｈ２）とをメタン（ＣＨ４）に変換する触媒反応（メタネーション反応）を利用して、二酸化炭素を含有する原料ガスからメタンを製造する装置が知られている。次の化１は、メタネーション反応式である。
［化１］　ＣＯ２＋４Ｈ２⇔ＣＨ４＋２Ｈ２Ｏ Conventionally, an apparatus for producing methane from a raw material gas containing carbon dioxide using a catalytic reaction (methanation reaction) that converts carbon dioxide (CO 2 ) and hydrogen (H 2 ) into methane (CH 4 ). Are known. The following chemical formula 1 is a methanation reaction formula.
[Chemical Formula 1] CO 2 + 4H 2 ⇔CH 4 + 2H 2 O
　メタネーション反応は発熱反応であるため、原料ガス及びその反応ガスは、反応場を通過する間に温度が上昇する。また、メタネーション反応は可逆反応であるため、温度が上昇することにより反応の平衡が化１の左辺側（原料側）に偏る。従って、メタネーション反応を促進するためには、反応場における温度上昇の抑制が効果的である。そこで、特許文献１，２では、反応器における温度上昇を抑制するメタン製造装置が提案されている。 Since the methanation reaction is an exothermic reaction, the temperature of the raw material gas and the reaction gas rise while passing through the reaction field. In addition, since the methanation reaction is a reversible reaction, the equilibrium of the reaction is biased toward the left side of the chemical formula 1 (raw material side) as the temperature rises. Therefore, in order to promote the methanation reaction, it is effective to suppress the temperature rise in the reaction field. Thus, Patent Documents 1 and 2 propose a methane production apparatus that suppresses a temperature rise in the reactor.
　特許文献１のメタネーション反応装置は、原料ガスと水素の一部を供給する第１反応器と、第１反応器から出たガスに水素の残部を供給する第２反応器と、第２反応器から出たガスの組成を調整する第３反応器とを備える。第１反応器の反応温度は、当該第１反応器への水素供給量によって調整される。 The methanation reactor of Patent Document 1 includes a first reactor for supplying a raw material gas and a part of hydrogen, a second reactor for supplying the remainder of hydrogen to the gas discharged from the first reactor, and a second reaction. A third reactor for adjusting the composition of the gas exiting the reactor. The reaction temperature of the first reactor is adjusted by the amount of hydrogen supplied to the first reactor.
　また、特許文献２のメタン製造装置は、触媒が収容された複数の反応器と、隣り合う２つの反応器をそれぞれ連通し、前段の反応器において生成された生成ガスを後段の反応器に送出する複数の連通ラインと、複数の反応器のうち、最も前段の反応器に原料ガスとともに水蒸気を導入する原料ガス導入部と、各連通ラインにおいて前段の反応器で生成された生成ガスをメタネーション反応が開始する温度まで冷却する冷却部とを備える。 Moreover, the methane production apparatus of Patent Document 2 communicates a plurality of reactors in which a catalyst is accommodated with two adjacent reactors, and sends the product gas generated in the former reactor to the latter reactor. A plurality of communication lines, a raw material gas introduction part that introduces steam together with the raw material gas into the first reactor among the plurality of reactors, and a methanation of the product gas generated in the first reactor in each communication line A cooling unit that cools to a temperature at which the reaction starts.
特開２０１３－１３６５３８号公報JP 2013-136538 A 特開２０１５－１０７９４３号公報Japanese Patent Laying-Open No. 2015-107943
　メタン製造装置で生成される製品ガスには比較的高いメタン濃度が要求される。しかし、前述の通り、メタネーション反応の転化率はメタネーション触媒の温度などによって変化することから、反応器から出た生成ガスのメタン濃度が変動することがある。特許文献１では、最終段の反応器を出た生成ガスは吸着塔においてメタンが分離され、分離されたメタンが製品ガスとして回収されるため、製品ガスのメタン濃度は高い値で安定する。しかし、生成ガスからメタンを分離させる装置は、比較的高価であり、メンテナンスが煩雑であることから、メタン製造装置から省略したいという要望もある。 A relatively high methane concentration is required for the product gas produced by the methane production equipment. However, as described above, since the conversion rate of the methanation reaction varies depending on the temperature of the methanation catalyst, the methane concentration of the product gas emitted from the reactor may vary. In Patent Document 1, methane is separated from the product gas exiting the final-stage reactor in an adsorption tower, and the separated methane is recovered as product gas. Therefore, the methane concentration of the product gas is stabilized at a high value. However, since the apparatus for separating methane from the product gas is relatively expensive and complicated to maintain, there is also a demand to omit it from the methane production apparatus.
　本発明は以上の事情に鑑みてされたものであり、その目的は、混合した水素と二酸化炭素とを含む原料ガスから製品ガスであるメタンを製造するメタン製造装置及び方法において、生成ガスからメタンを分離させる装置を省いても、製品ガスのメタン濃度をコントロールできる技術を提案することにある。 The present invention has been made in view of the above circumstances, and an object thereof is to provide a methane production apparatus and method for producing methane, which is a product gas, from a raw material gas containing mixed hydrogen and carbon dioxide. The purpose is to propose a technology that can control the methane concentration of the product gas even if the device for separating the gas is omitted.
　本発明の一態様に係るメタン製造装置は、混合した水素と二酸化炭素とを含む原料ガスから製品ガスであるメタンを製造するメタン製造装置であって、
メタネーション触媒が収容された反応器と、
前記反応器へ前記原料ガスを供給する原料ガス供給ラインと、
品質管理装置と、
前記反応器と前記品質管理装置とを接続し、前記反応器から出た前記生成ガスを前記品質管理装置へ送る生成ガスラインと、
前記製品ガスを貯える製品ガスタンクと、
前記品質管理装置と前記製品ガスタンクとを接続し、前記品質管理装置から出た前記製品ガスを前記製品ガスタンクへ送る製品ガスラインと、
前記品質管理装置と接続されたオフガスラインとを備え、
前記品質管理装置は、前記生成ガスのメタン濃度を検出するメタン濃度計と、前記生成ガスラインと接続される流路を前記製品ガスラインと前記オフガスラインとの間で切り替える流路切替器と、検出された前記メタン濃度が所定濃度以上のときに前記生成ガスラインと前記製品ガスラインとが接続され、検出された前記メタン濃度が前記所定濃度未満のときに前記生成ガスラインと前記オフガスラインとが接続されるように、前記流路切替器を動作させるコントローラとを有することを特徴としている。なお、前記反応器が、連通ラインで直列的に接続された複数の反応器を含んでいてもよい。 A methane production apparatus according to an aspect of the present invention is a methane production apparatus that produces methane, which is a product gas, from a raw material gas containing mixed hydrogen and carbon dioxide,
A reactor containing a methanation catalyst;
A source gas supply line for supplying the source gas to the reactor;
A quality control device,
A product gas line connecting the reactor and the quality control device, and sending the product gas from the reactor to the quality control device;
A product gas tank for storing the product gas;
A product gas line for connecting the quality control device and the product gas tank, and sending the product gas from the quality control device to the product gas tank;
An off-gas line connected to the quality control device,
The quality control device includes a methane concentration meter that detects a methane concentration of the product gas, a flow channel switch that switches a flow channel connected to the product gas line between the product gas line and the off-gas line, The generated gas line and the product gas line are connected when the detected methane concentration is equal to or higher than a predetermined concentration, and when the detected methane concentration is lower than the predetermined concentration, the generated gas line and the off-gas line are connected. And a controller for operating the flow path switching device so that the connection is established. The reactor may include a plurality of reactors connected in series via a communication line.
　これにより、メタン濃度が所定濃度以上の生成ガスのみが製品ガスタンクへ送られるので、回収する製品ガスのメタン濃度をコントロールすることができる。そして、生成ガスからメタンを分離させる装置を省略しても、純度の高いメタンを回収することができる。 Thereby, only the product gas having a methane concentration equal to or higher than the predetermined concentration is sent to the product gas tank, so that the methane concentration of the recovered product gas can be controlled. Even if a device for separating methane from the product gas is omitted, methane having high purity can be recovered.
　上記メタン製造装置において、前記オフガスラインの下流側端部が、前記原料ガス供給ラインと接続されていてよい。 In the methane production apparatus, a downstream end of the off-gas line may be connected to the source gas supply line.
　これにより、製品として回収されなかった生成ガスが、原料として再利用される。よって、資源を有効に活用することができ、また、温室効果ガスであるメタン及び二酸化炭素を含む生成ガスの大気排出量を低減することができる。 Thus, the product gas that has not been recovered as a product is reused as a raw material. Therefore, resources can be used effectively, and the atmospheric emission of product gas containing methane and carbon dioxide, which are greenhouse gases, can be reduced.
　上記メタン製造装置において、前記品質管理装置は、前記生成ガスラインに並列に接続された複数のオフガス容器を備え、前記複数のオフガス容器にメタン濃度が前記所定濃度未満のガスを貯溜してよい。 In the methane production apparatus, the quality control apparatus may include a plurality of off-gas containers connected in parallel to the product gas line, and store a gas having a methane concentration less than the predetermined concentration in the plurality of off-gas containers.
　このように、製品として回収されなかった生成ガス（即ち、オフガス）が複数のオフガス容器に一旦貯えられることによって、オフガスの排出タイミングや排出量をコントロールすることができる。 Thus, the production gas (that is, off gas) that has not been recovered as a product is temporarily stored in a plurality of off gas containers, whereby the off gas discharge timing and the discharge amount can be controlled.
　上記のメタン製造装置が、前記製品ガスラインに設けられた水素分離装置を更に備え、前記水素分離装置が、水素透過膜と、前記水素透過膜を介して一側に設けられた前記メタンが通るメタン流路と、前記水素透過膜を介して他側に設けられた前記水素と混合される前の前記二酸化炭素が通る二酸化炭素流路とを有していてよい。 The methane production apparatus further includes a hydrogen separation device provided in the product gas line, and the hydrogen separation device passes a hydrogen permeable membrane and the methane provided on one side through the hydrogen permeable membrane. A methane flow path and a carbon dioxide flow path through which the carbon dioxide before being mixed with the hydrogen provided on the other side through the hydrogen permeable membrane may be provided.
　これにより、生成ガスから分離されたメタンに含まれる水素を低減することができ、製品ガスタンクに回収されるメタンの純度を高めることができる。 This makes it possible to reduce the hydrogen contained in the methane separated from the product gas and increase the purity of the methane recovered in the product gas tank.
　上記のメタン製造装置が、前記最前段の反応器の前記触媒の温度を検出する温度センサと、前記原料ガス供給ラインに設けられた、バッファタンク、前記バッファタンクへ前記水素を供給する水素供給ライン、及び、前記バッファタンクへ前記二酸化炭素を供給する二酸化炭素供給ラインと、前記二酸化炭素供給ラインに設けられた放出弁と、検出された前記触媒の温度に基づいて、前記触媒の温度が所定温度以上のときに前記二酸化炭素供給ラインを通る前記二酸化炭素の少なくとも一部が系外へ放出され、前記触媒の温度が前記所定温度未満のときに前記放出弁が閉じられるように、前記放出弁を動作させる放出弁制御装置とを、更に備えていてよい。 The methane production apparatus includes a temperature sensor for detecting the temperature of the catalyst in the foremost reactor, a buffer tank provided in the source gas supply line, and a hydrogen supply line for supplying the hydrogen to the buffer tank And a carbon dioxide supply line for supplying the carbon dioxide to the buffer tank, a release valve provided in the carbon dioxide supply line, and a temperature of the catalyst detected based on the detected temperature of the catalyst. At least a part of the carbon dioxide passing through the carbon dioxide supply line is released out of the system at the above time, and the release valve is closed when the temperature of the catalyst is lower than the predetermined temperature. A discharge valve control device to be operated may be further provided.
　これにより、メタネーション触媒の温度が、例えば、メタネーション反応が停止する温度（又は、その近傍）まで上昇したときに、原料ガス中の二酸化炭素の割合を減らすことによって、反応器でのメタネーション反応を抑え、メタネーション触媒の温度を下げることができる。 Thus, when the temperature of the methanation catalyst rises to, for example, the temperature at which the methanation reaction stops (or in the vicinity thereof), the methanation in the reactor is reduced by reducing the proportion of carbon dioxide in the raw material gas. The reaction can be suppressed and the temperature of the methanation catalyst can be lowered.
　本発明の一態様に係るメタン製造方法は、
水素と二酸化炭素とを混合して原料ガスを調製する工程と、
前記原料ガス中の前記水素及び前記二酸化炭素をメタネーション触媒の存在下で反応させてメタン及び水を生成する工程と、
生成した前記メタン及び水、並びに、未反応の前記原料ガスを含む生成ガスのメタン濃度を検出する工程と、
検出された前記生成ガスのメタン濃度が所定濃度以上のときに前記生成ガスを製品ガスタンクへ送り、検出された前記生成ガスのメタン濃度が前記所定濃度未満のときに前記生成ガスをオフガスラインへ送る工程とを含むことを特徴としている。 A method for producing methane according to one embodiment of the present invention includes:
A step of preparing a raw material gas by mixing hydrogen and carbon dioxide;
Reacting the hydrogen and the carbon dioxide in the source gas in the presence of a methanation catalyst to produce methane and water;
Detecting the methane concentration of the produced gas containing the produced methane and water and the unreacted raw material gas;
When the detected methane concentration of the generated gas is equal to or higher than a predetermined concentration, the generated gas is sent to a product gas tank, and when the detected methane concentration of the generated gas is lower than the predetermined concentration, the generated gas is sent to an off-gas line. And a process.
　これにより、メタン濃度が所定濃度以上の生成ガスのみが製品ガスタンクへ送られるので、回収する製品ガスのメタン濃度をコントロールすることができる。そして、生成ガスからメタンを分離させる装置を省略しても、純度の高いメタンを回収することができる。 Thereby, only the product gas having a methane concentration equal to or higher than the predetermined concentration is sent to the product gas tank, so that the methane concentration of the recovered product gas can be controlled. Even if a device for separating methane from the product gas is omitted, methane having high purity can be recovered.
　上記メタン製造方法において、前記生成ガスを前記オフガスラインへ送る工程が、前記生成ガスを前記原料ガスに混入させることを含んでいてよい。 In the methane production method, the step of sending the generated gas to the off-gas line may include mixing the generated gas into the raw material gas.
　これにより、製品として回収されなかった生成ガスが、原料として再利用される。よって、資源を有効に活用することができ、また、温室効果ガスであるメタン及び二酸化炭素を含む生成ガスの大気排出量を低減することができる。 Thus, the product gas that has not been recovered as a product is reused as a raw material. Therefore, resources can be used effectively, and the atmospheric emission of product gas containing methane and carbon dioxide, which are greenhouse gases, can be reduced.
　上記メタン製造方法において、前記生成ガスを前記オフガスラインへ送る工程が、前記生成ガスを複数のガス容器に送ることを含んでいてよい。 In the methane production method, the step of sending the product gas to the off-gas line may include sending the product gas to a plurality of gas containers.
　このように、製品として回収されなかった生成ガスが複数のガス容器にいったん貯えられることによって、生成ガスの排出タイミングや排出量をコントロールすることができる。 Thus, the product gas that has not been recovered as a product is temporarily stored in a plurality of gas containers, whereby the discharge timing and the discharge amount of the product gas can be controlled.
　上記メタン製造方法において、前記生成ガスを前記製品ガスタンクへ送る工程が、前記生成ガスから分離した前記メタンと前記水素と混合される前の前記二酸化炭素との水素分圧差を利用して、水素透過膜を用いて前記メタンからそれに含まれる前記水素を除去することを含んでいてよい。 In the methane manufacturing method, the step of sending the product gas to the product gas tank uses a hydrogen partial pressure difference between the methane separated from the product gas and the carbon dioxide before being mixed with the hydrogen, to transmit hydrogen. Removing a hydrogen contained therein from the methane using a membrane may be included.
　これにより、生成ガスから分離されたメタンに含まれる水素を低減することができ、製品ガスタンクに回収されるメタンの純度を高めることができる。 This makes it possible to reduce the hydrogen contained in the methane separated from the product gas and increase the purity of the methane recovered in the product gas tank.
　本発明によれば、混合した水素と二酸化炭素とを含む原料ガスからメタンを製造するメタン製造装置及び方法において、生成ガスからメタンを分離させる装置を省略しても、製品ガスのメタン濃度をコントロールすることができる。 According to the present invention, in the methane production apparatus and method for producing methane from a raw material gas containing mixed hydrogen and carbon dioxide, the methane concentration of the product gas is controlled even if the apparatus for separating methane from the product gas is omitted. can do.
図１は、本発明の一実施形態に係るメタン製造装置の全体的な構成を示す図である。FIG. 1 is a diagram showing an overall configuration of a methane production apparatus according to an embodiment of the present invention. 図２は、水素分離装置の構成を示す図である。FIG. 2 is a diagram showing the configuration of the hydrogen separator. 図３は、品質管理装置の構成を示す図である。FIG. 3 is a diagram showing the configuration of the quality management apparatus. 図４は、品質管理装置の処理の流れを示す図である。FIG. 4 is a diagram showing a flow of processing of the quality management apparatus. 図５は、変形例１に係るメタン製造装置の品質管理装置の構成を示す図である。FIG. 5 is a diagram illustrating a configuration of a quality control apparatus for a methane production apparatus according to the first modification. 図６は、変形例２に係るメタン製造装置の品質管理装置の構成を示す図である。FIG. 6 is a diagram illustrating a configuration of a quality control apparatus for a methane production apparatus according to Modification 2.
　次に、図面を参照して本発明の実施の形態を説明する。本実施形態に係るメタン製造装置は、混合した水素と二酸化炭素とを含む原料ガスからメタンを製造するものである。 Next, an embodiment of the present invention will be described with reference to the drawings. The methane production apparatus according to this embodiment produces methane from a raw material gas containing mixed hydrogen and carbon dioxide.
〔メタン製造装置１００の構成〕
　図１は本発明の一実施形態に係るメタン製造装置１００の全体的な構成を示す図である。図１に示すメタン製造装置１００は、連通ライン１で直列に接続された複数の反応器Ｒ１，Ｒ２，・・・と、複数の反応器Ｒのうち最前段の反応器Ｒ１へ原料ガスを供給する原料ガス供給ライン２と、品質管理装置９と、複数の反応器Ｒのうち最終段の反応器Ｒ２と品質管理装置９とを接続する生成ガスライン３０と、製品ガスであるメタンを貯える製品ガスタンク４と、品質管理装置９と製品ガスタンク４とを接続する製品ガスライン４０と、品質管理装置９と接続されたオフガスライン８０とを備える。なお、複数の反応器Ｒ１，Ｒ２・・・のうち特定の反応器を指さない場合に「反応器Ｒ」と表す。 [Configuration of Methane Production Apparatus 100]
FIG. 1 is a diagram showing an overall configuration of a methane production apparatus 100 according to an embodiment of the present invention. A methane production apparatus 100 shown in FIG. 1 supplies a raw material gas to a plurality of reactors R1, R2,... Connected in series through a communication line 1 and to the foremost reactor R1 among the plurality of reactors R. The raw material gas supply line 2, the quality control device 9, the product gas line 30 connecting the final reactor R2 and the quality control device 9 among the plurality of reactors R, and the product that stores methane as the product gas A gas tank 4, a product gas line 40 connecting the quality control device 9 and the product gas tank 4, and an off-gas line 80 connected to the quality control device 9 are provided. In addition, when not pointing to a specific reactor among several reactor R1, R2 ..., it represents as "reactor R".
　本実施形態に係るメタン製造装置１００は、第１反応器Ｒ１と第２反応器Ｒ２との２つの反応器Ｒを備える。但し、反応器Ｒの数は３以上の複数であってもよい。各反応器Ｒには、水素及び二酸化炭素からメタン及び水を生成するメタネーション反応を促進させるメタネーション触媒が収容されている。メタネーション触媒は、特に限定されないが、例えば、市販のＮｉ系触媒であってよい。反応器Ｒ１，Ｒ２には、メタネーション触媒の温度を検出するための温度センサＴ１，Ｔ２が設けられている。 The methane production apparatus 100 according to the present embodiment includes two reactors R, a first reactor R1 and a second reactor R2. However, the number of reactors R may be three or more. Each reactor R contains a methanation catalyst that promotes a methanation reaction that produces methane and water from hydrogen and carbon dioxide. The methanation catalyst is not particularly limited, and may be a commercially available Ni-based catalyst, for example. The reactors R1 and R2 are provided with temperature sensors T1 and T2 for detecting the temperature of the methanation catalyst.
　第１反応器Ｒ１と第２反応器Ｒ２との間は、連通ライン１で接続されており、第１反応器Ｒ１から出た生成ガスは、連通ライン１を通じて第２反応器Ｒ２へ流入する。生成ガスには、メタネーション反応で生成したメタン及び水に加えて、未反応の二酸化炭素及び水素が含まれる。本実施形態では、反応器Ｒの数が２つであるため連通ライン１の数は１であるが、メタン製造装置１００は反応器Ｒの数に応じた数の連通ライン１を備える。 The first reactor R1 and the second reactor R2 are connected by a communication line 1, and the product gas discharged from the first reactor R1 flows into the second reactor R2 through the communication line 1. The product gas contains unreacted carbon dioxide and hydrogen in addition to methane and water produced by the methanation reaction. In this embodiment, since the number of reactors R is two, the number of communication lines 1 is 1, but the methane production apparatus 100 includes the number of communication lines 1 corresponding to the number of reactors R.
　連通ライン１には、第１熱交換器１１と、水分離器１２と、第２熱交換器１３とが設けられている。第１熱交換器１１では、生成ガスと冷却水との熱交換が行われる。水分離器１２では、第１熱交換器１１で冷却されることによって凝縮した生成ガス中の水分が、生成ガスから分離される。第２熱交換器１３では、反応器Ｒ２の冷却に利用されたホットオイルと生成ガスとの熱交換が行われる。第１熱交換器１１及び第２熱交換器１３によって、連通ライン１から次段の反応器（第２反応器Ｒ２）へ流入する生成ガスの温度は、メタネーション反応が開始する温度以上且つメタネーション反応が停止する温度未満に調整される。 The communication line 1 is provided with a first heat exchanger 11, a water separator 12, and a second heat exchanger 13. In the first heat exchanger 11, heat exchange between the generated gas and the cooling water is performed. In the water separator 12, the moisture in the product gas condensed by being cooled by the first heat exchanger 11 is separated from the product gas. In the second heat exchanger 13, heat exchange is performed between the hot oil used for cooling the reactor R2 and the product gas. The temperature of the product gas flowing from the communication line 1 into the next stage reactor (second reactor R2) by the first heat exchanger 11 and the second heat exchanger 13 is equal to or higher than the temperature at which the methanation reaction starts. The temperature is adjusted to below the temperature at which the nation reaction stops.
　原料ガス供給ライン２には、原料ガスが貯えられるバッファタンク２１と、バッファタンク２１から出た原料ガスを圧縮する圧縮機２２と、圧縮された原料ガスをメタネーション反応に適した温度に調整する熱交換器２３とが設けられている。 In the raw material gas supply line 2, a buffer tank 21 that stores the raw material gas, a compressor 22 that compresses the raw material gas discharged from the buffer tank 21, and the compressed raw material gas are adjusted to a temperature suitable for the methanation reaction. A heat exchanger 23 is provided.
　バッファタンク２１には、水素供給ライン２４から水素が供給され、二酸化炭素供給ライン２５から二酸化炭素が供給される。バッファタンク２１では、定常時は、水素と二酸化炭素の割合がモル比で４となるように（水素／二酸化炭素＝４）、均一に混合される。 The buffer tank 21 is supplied with hydrogen from the hydrogen supply line 24 and supplied with carbon dioxide from the carbon dioxide supply line 25. In the buffer tank 21, in a steady state, the hydrogen and carbon dioxide are mixed uniformly so that the molar ratio is 4 (hydrogen / carbon dioxide = 4).
　二酸化炭素供給ライン２５には、放出弁制御装置２７によって制御される放出弁２６が設けられている。放出弁制御装置２７は、温度センサＴ１で検出された第１反応器Ｒ１のメタネーション触媒の温度に基づいて、触媒の温度が所定温度以上のときに二酸化炭素供給ライン２５を通る二酸化炭素の少なくとも一部が系外へ放出され、触媒の温度が所定温度未満のときに放出弁２６が閉じられるように、放出弁２６を動作させる。これにより、第１反応器Ｒ１のメタネーション触媒の温度が所定温度以上のときは、バッファタンク２１から第１反応器Ｒ１へ送られる原料ガスの二酸化炭素の割合が上記定常時よりも小さくなる。 The carbon dioxide supply line 25 is provided with a discharge valve 26 controlled by a discharge valve control device 27. Based on the temperature of the methanation catalyst of the first reactor R1 detected by the temperature sensor T1, the release valve control device 27 is configured to output at least carbon dioxide passing through the carbon dioxide supply line 25 when the temperature of the catalyst is equal to or higher than a predetermined temperature. The release valve 26 is operated so that the release valve 26 is closed when a part is released out of the system and the temperature of the catalyst is lower than a predetermined temperature. Thereby, when the temperature of the methanation catalyst in the first reactor R1 is equal to or higher than a predetermined temperature, the ratio of carbon dioxide in the raw material gas sent from the buffer tank 21 to the first reactor R1 becomes smaller than that in the steady state.
　圧縮機２２では、原料ガスがメタネーション反応に適した圧力となるように圧縮される。メタネーション反応に適した圧力は、メタネーション触媒の種類や、反応器Ｒの仕様によって異なる。第１反応器Ｒ１に流入する原料ガスの圧力条件は、例えば、絶対圧で０～３ＭＰａである。 In the compressor 22, the raw material gas is compressed so as to have a pressure suitable for the methanation reaction. The pressure suitable for the methanation reaction varies depending on the type of methanation catalyst and the specifications of the reactor R. The pressure condition of the raw material gas flowing into the first reactor R1 is, for example, 0 to 3 MPa in absolute pressure.
　熱交換器２３では、第１反応器Ｒ１の冷却に利用されたホットオイルと原料ガスとの熱交換が行われ、原料ガスがメタネーション反応に適した温度に調整される。メタネーション反応に適した温度は、メタネーション触媒の種類や、反応器Ｒの段数によって異なる。例えば、第１反応器Ｒ１へ流入する原料ガスは約２５０～３５０℃であり、第２反応器Ｒ２へ流入する反応ガスは約１５０～２５０℃である。 In the heat exchanger 23, heat exchange between the hot oil used for cooling the first reactor R1 and the raw material gas is performed, and the raw material gas is adjusted to a temperature suitable for the methanation reaction. The temperature suitable for the methanation reaction varies depending on the type of methanation catalyst and the number of stages of the reactor R. For example, the raw material gas flowing into the first reactor R1 is about 250 to 350 ° C., and the reaction gas flowing into the second reactor R2 is about 150 to 250 ° C.
　最終段の反応器Ｒ２から出た生成ガスは、生成ガスライン３０を通じて品質管理装置９へ送られる。生成ガスライン３０には、熱交換器３１と、水分離器３２とが設けられている。熱交換器３１では、最終段の反応器Ｒ２から出た生成ガスと水との熱交換が行われる。水分離器３２では、熱交換器３１で冷却されることによって凝縮した生成ガス中の水分が分離される。 The product gas that has exited from the last-stage reactor R2 is sent to the quality control device 9 through the product gas line 30. The product gas line 30 is provided with a heat exchanger 31 and a water separator 32. In the heat exchanger 31, heat is exchanged between the product gas that has come out of the final-stage reactor R2 and water. In the water separator 32, the moisture in the product gas condensed by being cooled by the heat exchanger 31 is separated.
　品質管理装置９は、製品ガスライン４０を介して製品ガスタンク４と接続されている。また、品質管理装置９は、オフガスライン８０を介して、原料ガス供給ライン２と接続されている。品質管理装置９は、生成ガスのメタン濃度に基づいて、生成ガスライン３０と接続される流路を製品ガスライン４０とオフガスライン８０との間で切り替えるものである。品質管理装置９については、後ほど詳述する。 The quality control device 9 is connected to the product gas tank 4 via the product gas line 40. The quality control device 9 is connected to the raw material gas supply line 2 via the off gas line 80. The quality control device 9 switches the flow path connected to the product gas line 30 between the product gas line 40 and the off gas line 80 based on the methane concentration of the product gas. The quality management device 9 will be described in detail later.
　オフガスライン８０の下流側端部は、原料ガス供給ライン２の圧縮機２２よりも上流側と接続されている。本実施形態では、オフガスライン８０の下流側端部はバッファタンク２１と接続されている。但し、オフガスライン８０の下流側端部は、原料ガス供給ライン２のバッファタンク２１の下流側且つ圧縮機２２の上流側、又は、原料ガス供給ライン２のバッファタンク２１の上流側と接続されていてもよい。 The downstream end of the off gas line 80 is connected to the upstream side of the compressor 22 of the raw material gas supply line 2. In the present embodiment, the downstream end of the off gas line 80 is connected to the buffer tank 21. However, the downstream end of the off gas line 80 is connected to the downstream side of the buffer tank 21 of the raw material gas supply line 2 and the upstream side of the compressor 22 or the upstream side of the buffer tank 21 of the raw material gas supply line 2. May be.
　製品ガスライン４０には、生成ガスから水素を分離する水素分離装置４２が設けられている。水素分離装置４２で水素が分離されることによって、製品ガスタンク４に回収されるメタンの純度を更に高めることができる。 The product gas line 40 is provided with a hydrogen separator 42 for separating hydrogen from the product gas. By separating hydrogen by the hydrogen separator 42, the purity of methane recovered in the product gas tank 4 can be further increased.
　図２は、水素分離装置４２の構成を示す図である。図２に示す水素分離装置４２は、水素のみを通過させる水素透過膜７１と、水素透過膜７１を介して一側に設けられたメタン流路７２と、水素透過膜７１を介して他側に設けられた二酸化炭素流路７３とを含む。メタン分離装置３から出たメタンがメタン流路７２を通過する。また、二酸化炭素供給ライン２５の二酸化炭素、即ち、水素と混合される前の二酸化炭素が、二酸化炭素流路７３を通過する。メタン流路７２のメタンの流れと、二酸化炭素流路７３の二酸化炭素の流れは対向している。このような水素分離装置４２では、二酸化炭素流路７３を流れるガスの水素分圧は０であり、メタン流路７２を流れるガスの水素分圧は０よりも大きい（例えば、１００００Ｐａ）。この水素分圧の差をドライビングフォースとして、メタン流路７２を流れるガス中の水素が、水素透過膜７１を透過して、二酸化炭素流路７３へ移動する。 FIG. 2 is a diagram showing the configuration of the hydrogen separator 42. 2 includes a hydrogen permeable membrane 71 that allows only hydrogen to pass through, a methane channel 72 provided on one side via the hydrogen permeable membrane 71, and a hydrogen permeable membrane 71 on the other side via the hydrogen permeable membrane 71. And a carbon dioxide channel 73 provided. Methane emitted from the methane separator 3 passes through the methane flow path 72. Further, carbon dioxide in the carbon dioxide supply line 25, that is, carbon dioxide before being mixed with hydrogen passes through the carbon dioxide flow path 73. The flow of methane in the methane flow path 72 and the flow of carbon dioxide in the carbon dioxide flow path 73 are opposed to each other. In such a hydrogen separator 42, the hydrogen partial pressure of the gas flowing through the carbon dioxide channel 73 is 0, and the hydrogen partial pressure of the gas flowing through the methane channel 72 is greater than 0 (for example, 10,000 Pa). Using the difference in hydrogen partial pressure as a driving force, hydrogen in the gas flowing through the methane passage 72 passes through the hydrogen permeable membrane 71 and moves to the carbon dioxide passage 73.
〔メタン製造方法〕
　ここで、上記構成のメタン製造装置１００を用いたメタン製造方法を説明する。 [Methane production method]
Here, a methane production method using the methane production apparatus 100 having the above configuration will be described.
　先ず、バッファタンク２１で、水素供給ライン２４から供給された水素と二酸化炭素供給ライン２５から供給された二酸化炭素とが所定の割合で混合して、原料ガスが調製される。 First, in the buffer tank 21, hydrogen supplied from the hydrogen supply line 24 and carbon dioxide supplied from the carbon dioxide supply line 25 are mixed at a predetermined ratio to prepare a raw material gas.
　原料ガスは、圧縮機２２及び熱交換器２３を経て、第１反応器Ｒ１に流入する。第１反応器Ｒ１では、原料ガス中の水素及び二酸化炭素がメタネーション触媒の存在下でメタネーション反応して、メタン及び水が生成される。第１反応器Ｒ１で生成されたメタン及び水、並びに、未反応の水素及び二酸化炭素を含む生成ガスは、連通ライン１へ流出する。 The raw material gas flows into the first reactor R1 through the compressor 22 and the heat exchanger 23. In the first reactor R1, hydrogen and carbon dioxide in the raw material gas undergo a methanation reaction in the presence of a methanation catalyst to produce methane and water. Methane and water produced in the first reactor R1 and product gas containing unreacted hydrogen and carbon dioxide flow out to the communication line 1.
　連通ライン１に流れ出た生成ガスは、第１熱交換器１１、水分離器１２、及び第２熱交換器１３を経て第２反応器Ｒ２に流入する。第２反応器Ｒ２でも、生成ガス中の水素及び二酸化炭素がメタネーション触媒の存在下でメタネーション反応して、メタン及び水が生成される。第２反応器Ｒ２で生成されたメタン及び水、並びに、未反応の水素及び二酸化炭素を含む生成ガスは、生成ガスライン３０へ流出する。 The product gas flowing out to the communication line 1 flows into the second reactor R2 through the first heat exchanger 11, the water separator 12, and the second heat exchanger 13. In the second reactor R2, too, hydrogen and carbon dioxide in the product gas undergo a methanation reaction in the presence of a methanation catalyst to produce methane and water. Methane and water produced in the second reactor R2 and product gas containing unreacted hydrogen and carbon dioxide flow out to the product gas line 30.
　生成ガスライン３０に流れ出た生成ガスは、熱交換器３１及び水分離器３２を経て品質管理装置９へ流入する。品質管理装置９は、メタン濃度が所定濃度以上の生成ガスを製品ガスライン４０へ送る。製品ガスライン４０へ流入した生成ガス（即ち、製品ガス）は、製品ガスタンク４へ流入し、製品ガスとして回収される。一方、品質管理装置９は、メタン濃度が所定濃度未満の生成ガスを生成ガスライン３０へ送る、又は、後述するオフガス容器Ｐ1～ＰNに貯える。 The product gas that has flowed out to the product gas line 30 flows into the quality control device 9 through the heat exchanger 31 and the water separator 32. The quality control device 9 sends a product gas having a methane concentration equal to or higher than a predetermined concentration to the product gas line 40. The product gas that flows into the product gas line 40 (that is, product gas) flows into the product gas tank 4 and is recovered as product gas. On the other hand, the quality control device 9 sends a product gas having a methane concentration less than a predetermined concentration to the product gas line 30 or stores it in off-gas containers P1 to PN described later.
〔品質管理装置９の構成及び動作〕
　ここで、品質管理装置９について詳細に説明する。図３は、品質管理装置の構成を示す図である。 [Configuration and operation of quality control device 9]
Here, the quality management device 9 will be described in detail. FIG. 3 is a diagram showing the configuration of the quality management apparatus.
　図３に示すように、品質管理装置９は、メタン濃度計９１と、生成ガスライン３０と接続された複数のガス容器Ｐ0～ＰN（Ｎは１以上の自然数）と、各ガス容器Ｐ0～ＰNの入口に設けられた入口弁Ｋ0～ＫNと、各ガス容器Ｐ0～ＰNの出口に設けられた出口弁Ｊ0～ＪNと、各ガス容器Ｐ0～ＰNに設けられた圧力計Ｖ0～ＶNと、コントローラ９３とを含む。複数のガス容器Ｐ0～ＰNは、少なくとも１つの製品ガス容器Ｐ0と、少なくとも１つのオフガス容器Ｐ1～ＰNとを含む。 As shown in FIG. 3, the quality control device 9 includes a methane concentration meter 91, a plurality of gas containers P0 to PN (N is a natural number of 1 or more) connected to the product gas line 30, and each gas container P0 to PN. Inlet valves K0 to KN provided at the inlet of the gas, outlet valves J0 to JN provided at the outlets of the gas containers P0 to PN, pressure gauges V0 to VN provided to the gas containers P0 to PN, and a controller 93. The plurality of gas containers P0 to PN include at least one product gas container P0 and at least one offgas container P1 to PN.
　製品ガス容器Ｐ0は、メタン濃度が所定濃度以上の生成ガスを一時的に貯えるものである。所定濃度は、任意のメタン濃度であって、例えば、９０％以上の数である。製品ガス容器Ｐ0の入口は生成ガスライン３０と接続されており、製品ガス容器Ｐ0の出口は製品ガスライン４０と接続されている。更に、製品ガス容器Ｐ0には、パージライン９４が接続されており、パージライン９４にはパージ弁９５が設けられている。このパージ弁９５と、前述の入口弁Ｋ0～ＫN及び出口弁Ｊ0～ＪNとが、生成ガスライン３０と接続される流路を製品ガスライン４０とオフガスライン８０との間で切り替える流路切替器として機能する。 The product gas container P0 temporarily stores a generated gas having a methane concentration equal to or higher than a predetermined concentration. The predetermined concentration is an arbitrary methane concentration, for example, a number of 90% or more. The inlet of the product gas container P 0 is connected to the product gas line 30, and the outlet of the product gas container P 0 is connected to the product gas line 40. Further, a purge line 94 is connected to the product gas container P 0, and a purge valve 95 is provided in the purge line 94. This purge valve 95 and the above-described inlet valves K0 to KN and outlet valves J0 to JN switch the flow path connected to the product gas line 30 between the product gas line 40 and the off gas line 80. Function as.
　オフガス容器Ｐ1～ＰNは、メタン濃度が所定濃度未満の生成ガスを一時的に貯えるものである。各オフガス容器Ｐ1～ＰNの入口は生成ガスライン３０と接続されており、各オフガス容器Ｐ1～ＰNの出口はオフガスライン８０と接続されている。つまり、複数のオフガス容器Ｐ1～ＰNは並列に生成ガスライン３０と接続されており、複数のオフガス容器Ｐ1～ＰNは並列にオフガスライン８０と接続されている。 The off-gas containers P1 to PN temporarily store generated gas having a methane concentration lower than a predetermined concentration. The inlets of the off gas containers P1 to PN are connected to the product gas line 30, and the outlets of the off gas containers P1 to PN are connected to the off gas line 80. That is, the plurality of offgas containers P1 to PN are connected in parallel to the product gas line 30, and the plurality of offgas containers P1 to PN are connected to the offgas line 80 in parallel.
　メタン濃度計９１は、水分離器３２より下流側且つ各品質管理装置９よりも上流側に設けられている。このメタン濃度計９１で検出されたメタン濃度は、コントローラ９３へ出力される。また、各圧力計Ｖ0～ＶNで検出された各ガス容器Ｐ0～ＰN内の圧力は、コントローラ９３へ出力される。 The methane concentration meter 91 is provided downstream from the water separator 32 and upstream from each quality control device 9. The methane concentration detected by the methane concentration meter 91 is output to the controller 93. The pressures in the gas containers P0 to PN detected by the pressure gauges V0 to VN are output to the controller 93.
　コントローラ９３は、メタン濃度計９１からメタン濃度を取得し、各圧力計Ｖ0～ＶNから圧力を取得し、これらの値に基づいて流路切替器（入口弁Ｋ0～ＫN、出口弁Ｊ0～ＪN、及びパージ弁９５）の動作を制御する。コントローラ９３は、プロセッサ及びメモリを備えたコンピュータで構成されており、プロセッサで所定のプログラムを実行することにより、後述するコントローラ９３としての機能を備える。 The controller 93 acquires the methane concentration from the methane concentration meter 91, acquires the pressure from each of the pressure gauges V0 to VN, and based on these values, the flow path switch (inlet valve K0 to KN, outlet valve J0 to JN, And the operation of the purge valve 95). The controller 93 is composed of a computer including a processor and a memory, and has a function as a controller 93 described later by executing a predetermined program by the processor.
　ここで、図４を用いて、品質管理装置９の処理の流れについて説明する。図４は、品質管理装置９の処理の流れを示す図である。カウンタの値はｎ（ｎは１以上Ｎ以下の自然数）とする。 Here, the processing flow of the quality control apparatus 9 will be described with reference to FIG. FIG. 4 is a diagram showing the flow of processing of the quality management device 9. The counter value is n (n is a natural number between 1 and N).
　製品ガス容器Ｐ0の入口弁Ｋ0及び出口弁Ｊ0が開放され、オフガス容器Ｐ1～ＰNの入口弁Ｋ1～ＫN及び出口弁Ｊ1～ＪNが閉止され、パージ弁９５が閉止された状態からスタートする（ステップＳ１）。この状態では、最終段の反応器Ｒ２から出た反応ガスは、熱交換器３１及び水分離器３２を経て製品ガス容器Ｐ0に流入し、更に、製品ガス容器Ｐ0から製品ガスライン４０を通じて製品ガスタンク４へ流入する。 Starting from the state where the inlet valve K0 and outlet valve J0 of the product gas container P0 are opened, the inlet valves K1 to KN and outlet valves J1 to JN of the offgas containers P1 to PN are closed, and the purge valve 95 is closed (step). S1). In this state, the reaction gas exiting from the final-stage reactor R2 flows into the product gas container P0 through the heat exchanger 31 and the water separator 32, and further from the product gas container P0 through the product gas line 40 to the product gas tank. Flows into 4.
　コントローラ９３は、メタン濃度計９１で検出されるメタン濃度を常時監視する。コントローラ９３は、検出されたメタン濃度が所定濃度以上であれば（ステップＳ２でＹＥＳ）、ステップＳ１に戻って処理を続ける。一方、コントローラ９３は、検出されたメタン濃度が所定濃度未満であれば（Ｓ２でＮＯ）、ステップＳ３に進む。 The controller 93 constantly monitors the methane concentration detected by the methane concentration meter 91. If the detected methane concentration is equal to or higher than the predetermined concentration (YES in step S2), the controller 93 returns to step S1 and continues the process. On the other hand, if the detected methane concentration is less than the predetermined concentration (NO in S2), the controller 93 proceeds to step S3.
　ステップＳ３では、コントローラ９３は、製品ガス容器Ｐ0の入口弁Ｋ0及び出口弁Ｊ0が閉止され、オフガス容器Ｐnの入口弁Ｋnが開放され、オフガス容器Ｐnの出口弁Jnが閉止され、オフガス容器Ｐnを除くオフガス容器Ｐ1～ＰNの入口弁Ｋ1～ＫN及び出口弁Ｊ1～ＪNが閉止されるように、流路切替器を動作させる。これにより、最終段の反応器Ｒ２から出た反応ガスは、熱交換器３１及び水分離器３２を経てオフガス容器Ｐnに流入し、オフガス容器Ｐnに貯溜される。更に、反応ガス（製品ガス）は、製品ガス容器Ｐ0から製品ガスライン４０を通じて製品ガスタンク４へ流入する。 In step S3, the controller 93 closes the inlet valve K0 and outlet valve J0 of the product gas container P0, opens the inlet valve Kn of the offgas container Pn, closes the outlet valve Jn of the offgas container Pn, and turns off the offgas container Pn. The flow path switch is operated so that the inlet valves K1 to KN and the outlet valves J1 to JN of the off-gas containers P1 to PN are closed. As a result, the reaction gas exiting from the final reactor R2 flows into the offgas container Pn via the heat exchanger 31 and the water separator 32, and is stored in the offgas container Pn. Further, the reaction gas (product gas) flows into the product gas tank 4 through the product gas line 40 from the product gas container P0.
　ここで、コントローラ９３は、オフガス容器Ｐn内の圧力と所定圧力とを比較する。所定圧力は、任意の値であって、例えば、オフガス容器Ｐ1～ＰNの設計圧力である。オフガス容器Ｐn内の圧力が所定圧力未満であれば（ステップＳ４でＹＥＳ）、オフガス容器Ｐnの残容量にまだ余裕がある。一方、オフガス容器Ｐn内の圧力が所定圧力以上となれば（ステップＳ４でＮＯ）、オフガス容器Ｐnが満杯になったとして、コントローラ９３はｎに１を足した数を新たなｎとする（ｎ＝ｎ＋１）（ステップＳ５）。但し、ｎがＮの場合は、新たなｎは１とする。そして、コントローラ９３は、新たなｎについて、ステップＳ３を繰り返す。このようにして、検出されたメタン濃度が所定濃度以上となるまで、オフガス容器Ｐ1～ＰNに順次オフガスを貯めていく。 Here, the controller 93 compares the pressure in the off-gas container Pn with a predetermined pressure. The predetermined pressure is an arbitrary value, for example, a design pressure of the off-gas containers P1 to PN. If the pressure in the offgas container Pn is less than the predetermined pressure (YES in step S4), there is still a margin in the remaining capacity of the offgas container Pn. On the other hand, if the pressure in the off-gas container Pn is equal to or higher than the predetermined pressure (NO in step S4), the controller 93 assumes that the off-gas container Pn is full and sets n to 1 as a new n (n = N + 1) (step S5). However, when n is N, the new n is 1. And the controller 93 repeats step S3 about new n. In this manner, the offgas is sequentially stored in the offgas containers P1 to PN until the detected methane concentration becomes a predetermined concentration or more.
　コントローラ９３は、検出されたメタン濃度が所定濃度以上となれば（ステップＳ６でＹＥＳ）、パージ弁９５が開放され、製品ガス容器Ｐ0の入口弁Ｋ0が開放され、製品ガス容器Ｐ0の出口弁Ｊ0が閉止され、オフガス容器Ｐ1～ＰNの入口弁Ｋ1～ＫN及び出口弁Ｊ1～ＪNが閉止されるように、流路切替器を動作させる（ステップＳ７）。これにより、最終段の反応器Ｒ２を出た生成ガスは、製品ガス容器Ｐ0へ流入し、パージライン９４を通じてオフガスライン８０へ流出する。その結果、メタン濃度計９１より下流側の生成ガスライン３０、及び、メタン濃度が所定濃度未満の生成ガスが流入している可能性のある製品ガス容器Ｐ0内が、メタン濃度が所定濃度以上の生成ガスでパージされる。 If the detected methane concentration is equal to or higher than the predetermined concentration (YES in step S6), the controller 93 opens the purge valve 95, opens the inlet valve K0 of the product gas container P0, and outputs the outlet valve J0 of the product gas container P0. Is closed, and the flow path switching device is operated so that the inlet valves K1 to KN and the outlet valves J1 to JN of the off gas containers P1 to PN are closed (step S7). As a result, the product gas exiting the final-stage reactor R2 flows into the product gas container P0 and flows out to the off-gas line 80 through the purge line 94. As a result, the product gas line 30 on the downstream side of the methane concentration meter 91 and the product gas container P0 in which the product gas having a methane concentration less than the predetermined concentration may flow in have a methane concentration equal to or higher than the predetermined concentration. Purge with product gas.
　そして、所定のパージ処理時間が経過すると（ステップＳ８でＹＥＳ）、処理がステップＳ１に戻って、コントローラ９３は、製品ガス容器Ｐ0の入口弁Ｋ0及び出口弁Ｊ0が開放され、オフガス容器Ｐ1～ＰNの入口弁Ｋ1～ＫN及び出口弁Ｊ1～ＪNが閉止され、パージ弁９５が閉止さされるように、流路切替器を動作させる。 When the predetermined purge processing time has elapsed (YES in step S8), the process returns to step S1, and the controller 93 opens the inlet valve K0 and outlet valve J0 of the product gas container P0, and the offgas containers P1 to PN. The flow path switch is operated so that the inlet valves K1 to KN and the outlet valves J1 to JN are closed and the purge valve 95 is closed.
　なお、上記のようにオフガス容器Ｐ1～ＰNに貯められたオフガスは、反応器Ｒの熱暴走を抑止するために用いられてよい。この場合、コントローラ９３は、温度センサＴ１で検出された第１反応器Ｒ１のメタネーション触媒の温度に基づいて、触媒の温度が所定温度以上のときにオフガス容器Ｐ1～ＰNの少なくとも１つの出口弁Ｊ1～ＪNを開放する。これにより、オフガスライン８０へ流出したオフガスは、原料ガス供給ライン２を流れる原料ガスに混入する。メタン濃度の高いオフガスが混入した原料ガスが第１反応器Ｒに流入すると、第１反応器Ｒ１のメタネーション反応が抑えられ、メタネーション触媒の温度の上昇を抑えることができる。 The off gas stored in the off gas containers P1 to PN as described above may be used to suppress the thermal runaway of the reactor R. In this case, based on the temperature of the methanation catalyst of the first reactor R1 detected by the temperature sensor T1, the controller 93 at least one outlet valve of the offgas containers P1 to PN when the temperature of the catalyst is equal to or higher than a predetermined temperature. Open J1-JN. As a result, the off-gas flowing out to the off-gas line 80 is mixed into the source gas flowing through the source gas supply line 2. When the raw material gas mixed with the off-gas having a high methane concentration flows into the first reactor R, the methanation reaction in the first reactor R1 is suppressed, and an increase in the temperature of the methanation catalyst can be suppressed.
　また、オフガス容器Ｐ1～ＰNの全てが所定圧力となったときは、メタン製造装置１００の運転を停止してよい。 Further, when all of the off-gas containers P1 to PN are at a predetermined pressure, the operation of the methane production apparatus 100 may be stopped.
　以上に説明したように、本実施形態のメタン製造装置１００は、メタネーション触媒が収容された反応器Ｒと、反応器Ｒへ原料ガスを供給する原料ガス供給ライン２と、品質管理装置９と、反応器Ｒと品質管理装置９とを接続し、反応器Ｒから出た生成ガスを品質管理装置９へ送る生成ガスライン３０と、製品ガスを貯える製品ガスタンク４と、品質管理装置９と製品ガスタンク４とを接続し、品質管理装置９から出た製品ガスを製品ガスタンク４へ送る製品ガスライン４０と、品質管理装置９と接続されたオフガスライン８０とを備える。品質管理装置９は、生成ガスのメタン濃度を検出するメタン濃度計９１と、生成ガスライン３０と接続される流路を製品ガスライン４０とオフガスライン８０との間で切り替える流路切替器（入口弁Ｋ0～ＫN、出口弁Ｊ0～ＪN）と、検出されたメタン濃度が所定濃度以上のときに生成ガスライン３０と製品ガスライン４０とが接続され、検出されたメタン濃度が所定濃度未満のときに生成ガスライン３０とオフガスライン８０とが接続されるように、流路切替器を動作させるコントローラ９３とを備える。なお、本実施形態では、反応器Ｒが連通ライン１で直列的に接続された複数の反応器Ｒ１，Ｒ２を含むが、反応器Ｒは単数であってもよい。 As described above, the methane production apparatus 100 of the present embodiment includes the reactor R in which the methanation catalyst is accommodated, the source gas supply line 2 that supplies the source gas to the reactor R, and the quality control apparatus 9. The reactor R and the quality control device 9 are connected, the product gas line 30 for sending the product gas from the reactor R to the quality control device 9, the product gas tank 4 for storing the product gas, the quality control device 9 and the product The product gas line 40 which connects the gas tank 4 and sends the product gas emitted from the quality control device 9 to the product gas tank 4 and the off gas line 80 connected to the quality control device 9 are provided. The quality control device 9 includes a methane concentration meter 91 that detects the methane concentration of the product gas, and a flow path switch (inlet) that switches the flow path connected to the product gas line 30 between the product gas line 40 and the off-gas line 80. Valve K0 to KN, outlet valve J0 to JN) and the product gas line 30 and the product gas line 40 are connected when the detected methane concentration is equal to or higher than the predetermined concentration, and when the detected methane concentration is lower than the predetermined concentration And a controller 93 that operates the flow path switch so that the product gas line 30 and the off-gas line 80 are connected to each other. In this embodiment, the reactor R includes a plurality of reactors R1 and R2 connected in series by the communication line 1, but the reactor R may be singular.
　同様に、本実施形態に係るメタン製造方法は、水素と二酸化炭素とを混合して原料ガスを調製する工程と、原料ガス中の水素及び二酸化炭素をメタネーション触媒の存在下で反応させてメタン及び水を生成する工程と、生成したメタン及び水、並びに、未反応の原料ガスを含む生成ガスのメタン濃度を検出する工程と、検出された生成ガスのメタン濃度が所定濃度以上のときに生成ガスを製品ガスタンク４へ送り、検出された生成ガスのメタン濃度が所定濃度未満のときに生成ガスをオフガスライン８０へ送る工程とを含む。 Similarly, the method for producing methane according to the present embodiment includes a step of preparing a raw material gas by mixing hydrogen and carbon dioxide, and reacting hydrogen and carbon dioxide in the raw material gas in the presence of a methanation catalyst. And a step of generating water, a step of detecting the generated methane and water, and a step of detecting the methane concentration of the generated gas including the unreacted raw material gas, and when the detected methane concentration of the generated gas is equal to or higher than a predetermined concentration. Sending the gas to the product gas tank 4 and sending the produced gas to the off-gas line 80 when the detected methane concentration of the produced gas is less than a predetermined concentration.
　本実施形態に係るメタン製造装置１００及び方法によれば、メタン濃度が所定濃度以上の生成ガスのみが製品ガスタンク４へ送られるので、回収する製品ガスのメタン濃度をコントロールすることができる。そして、生成ガスからメタンを分離させる装置を省略しても、純度の高いメタンを回収することができる。 According to the methane production apparatus 100 and method according to the present embodiment, only the product gas having a methane concentration equal to or higher than the predetermined concentration is sent to the product gas tank 4, so that the methane concentration of the product gas to be recovered can be controlled. Even if a device for separating methane from the product gas is omitted, methane having high purity can be recovered.
　また、本実施形態に係るメタン製造装置１００において、オフガスライン８０の下流側端部が、原料ガス供給ライン２と接続されている。 In the methane production apparatus 100 according to this embodiment, the downstream end of the off-gas line 80 is connected to the raw material gas supply line 2.
　同様に、本実施形態に係るメタン製造方法では、生成ガスをオフガスライン８０へ送る工程が、生成ガスを原料ガスに混入させることを含む。 Similarly, in the methane manufacturing method according to the present embodiment, the step of sending the generated gas to the off-gas line 80 includes mixing the generated gas into the raw material gas.
　これにより、製品として回収されなかった生成ガスが、原料として再利用される。よって、資源を有効に活用することができ、また、温室効果ガスであるメタン及び二酸化炭素を含む生成ガスの大気排出量を低減することができる。 Thus, the product gas that has not been recovered as a product is reused as a raw material. Therefore, resources can be used effectively, and the atmospheric emission of product gas containing methane and carbon dioxide, which are greenhouse gases, can be reduced.
　また、本実施形態に係るメタン製造装置１００において、品質管理装置９は、生成ガスライン３０に並列に接続された複数のオフガス容器Ｐ1～ＰNを備え、複数のオフガス容器Ｐ1～ＰNにメタン濃度が所定濃度未満のガス（即ち、オフガス）を貯溜する。 In the methane production apparatus 100 according to the present embodiment, the quality control apparatus 9 includes a plurality of off-gas containers P1 to PN connected in parallel to the product gas line 30, and the methane concentration in the plurality of off-gas containers P1 to PN. A gas having a concentration lower than a predetermined concentration (that is, off-gas) is stored.
　同様に、本実施形態に係るメタン製造方法では、生成ガスをオフガスライン８０へ送る工程が、生成ガスを複数のガス容器Ｐ1～ＰNに送ることを含む。 Similarly, in the methane production method according to the present embodiment, the step of sending the product gas to the off-gas line 80 includes sending the product gas to a plurality of gas containers P1 to PN.
　このように、製品として回収されなかった生成ガス（即ち、オフガス）が複数のオフガス容器Ｐ1～ＰNに一旦貯えられることによって、オフガスの排出タイミングや排出量をコントロールすることができる。 Thus, the production gas (that is, off gas) that has not been recovered as a product is temporarily stored in the plurality of off gas containers P1 to PN, whereby the off gas discharge timing and the discharge amount can be controlled.
　また、本実施形態に係るメタン製造装置１００は、製品ガスライン４０に設けられた水素分離装置４２を更に備える。この水素分離装置４２は、水素透過膜７１と、水素透過膜７１を介して一側に設けられたメタンが通るメタン流路７２と、水素透過膜７１を介して他側に設けられた水素と混合される前の二酸化炭素が通る二酸化炭素流路７３とを有する。 Moreover, the methane production apparatus 100 according to the present embodiment further includes a hydrogen separator 42 provided in the product gas line 40. This hydrogen separator 42 includes a hydrogen permeable membrane 71, a methane passage 72 through which methane is provided on one side via the hydrogen permeable membrane 71, hydrogen provided on the other side via the hydrogen permeable membrane 71, And a carbon dioxide channel 73 through which carbon dioxide before being mixed passes.
　同様に、本実施形態に係るメタン製造方法において、生成ガスを製品ガスタンク４へ送る工程が、生成ガスから分離したメタンと水素と混合される前の二酸化炭素との水素分圧差を利用して、水素透過膜７１を用いてメタンからそれに含まれる水素を除去することを含む。 Similarly, in the methane production method according to the present embodiment, the step of sending the product gas to the product gas tank 4 utilizes the hydrogen partial pressure difference between methane separated from the product gas and carbon dioxide before being mixed with hydrogen, This includes removing hydrogen contained in methane from the methane using the hydrogen permeable membrane 71.
　これにより、生成ガスから分離されたメタンに含まれる水素を低減することができ、製品ガスタンク４に回収されるメタンの純度を高めることができる。 Thereby, hydrogen contained in methane separated from the product gas can be reduced, and the purity of methane recovered in the product gas tank 4 can be increased.
　また、本実施形態に係るメタン製造装置１００において、最前段の反応器Ｒ１の触媒の温度を検出する温度センサＴ１と、原料ガス供給ライン２に設けられた、バッファタンク２１、バッファタンク２１へ水素を供給する水素供給ライン２４、及び、バッファタンク２１へ二酸化炭素を供給する二酸化炭素供給ライン２５と、二酸化炭素供給ライン２５に設けられた放出弁２６と、検出された触媒の温度に基づいて、触媒の温度が所定温度以上のときに二酸化炭素供給ライン２５を通る二酸化炭素の少なくとも一部が系外へ放出され、触媒の温度が所定温度未満のときに放出弁２６が閉じられるように、放出弁２６を動作させる放出弁制御装置２７とを、更に備える。 Further, in the methane production apparatus 100 according to this embodiment, the temperature sensor T1 that detects the temperature of the catalyst in the foremost reactor R1, and the buffer tank 21 provided in the source gas supply line 2 and the buffer tank 21 are supplied with hydrogen. Based on the hydrogen supply line 24 for supplying the carbon dioxide, the carbon dioxide supply line 25 for supplying carbon dioxide to the buffer tank 21, the release valve 26 provided in the carbon dioxide supply line 25, and the detected temperature of the catalyst, Release so that at least part of the carbon dioxide passing through the carbon dioxide supply line 25 is released out of the system when the temperature of the catalyst is equal to or higher than the predetermined temperature, and the release valve 26 is closed when the temperature of the catalyst is lower than the predetermined temperature. A discharge valve control device 27 for operating the valve 26 is further provided.
　これにより、メタネーション触媒の温度が、例えば、メタネーション反応が停止する温度（又は、その近傍）まで上昇したときに、原料ガス中の二酸化炭素の割合を減らすことによって、反応器Ｒでのメタネーション反応を抑え、メタネーション触媒の温度を下げることができる。 As a result, when the temperature of the methanation catalyst rises to, for example, the temperature at which the methanation reaction stops (or in the vicinity thereof), the proportion of carbon dioxide in the raw material gas is reduced, thereby reducing the metathesis in the reactor R. Nation reaction can be suppressed and the temperature of the methanation catalyst can be lowered.
　以上に本発明の好適な実施の形態を説明したが、本発明の精神を逸脱しない範囲で、上記実施形態の具体的な構造及び／又は機能の詳細を変更したものも本発明に含まれ得る。上記のメタン製造装置１００の構成は、例えば、以下のように変更することができる。なお、以下に説明する変形例１，２の説明においては、前述の実施形態と同一又は類似の部材には図面に同一の符号を付し、説明を省略する。 The preferred embodiments of the present invention have been described above, but the present invention may include modifications in the specific structure and / or function details of the above embodiments without departing from the spirit of the present invention. . The configuration of the methane production apparatus 100 can be changed, for example, as follows. In the description of the first and second modifications described below, the same or similar members as those of the above-described embodiment are denoted by the same reference numerals in the drawings, and the description thereof is omitted.
（変形例１）
　図５は、変形例１に係るメタン製造装置１００の品質管理装置９Ａの構成を示す図である。図５に示すように、変形例１に係るメタン製造装置１００では、前述の実施形態に係る品質管理装置９から品質管理装置９Ａの構成を変更している。 (Modification 1)
FIG. 5 is a diagram illustrating a configuration of the quality control device 9A of the methane production apparatus 100 according to the first modification. As shown in FIG. 5, in the methane production apparatus 100 according to the first modification, the configuration of the quality management apparatus 9A is changed from the quality management apparatus 9 according to the above-described embodiment.
　品質管理装置９Ａは、メタン濃度計９１と、生成ガスライン３０と接続された複数のオフガス容器Ｐ1～ＰN（Ｎは１以上の自然数）と、各オフガス容器Ｐ1～ＰNの入口に設けられた入口弁Ｋ1～ＫNと、各オフガス容器Ｐ1～ＰNの出口に設けられた出口弁Ｊ1～ＪNと、各ガス容器Ｐ1～ＰNに設けられた圧力計Ｖ1～ＶNと、生成ガスライン３０と接続された開閉弁９９と、コントローラ９３とを含む。 The quality control device 9A includes a methane concentration meter 91, a plurality of off-gas containers P1 to PN (N is a natural number of 1 or more) connected to the product gas line 30, and inlets provided at the inlets of the off-gas containers P1 to PN. The valves K1 to KN, outlet valves J1 to JN provided at the outlets of the off-gas containers P1 to PN, pressure gauges V1 to VN provided to the gas containers P1 to PN, and the generated gas line 30 were connected. An on-off valve 99 and a controller 93 are included.
　品質管理装置９Ａでは、前述の実施形態に係る品質管理装置９の製品ガス容器Ｐ0、製品ガス容器Ｐ0の入口弁Ｋ0、製品ガス容器Ｐ0の出口弁Ｊ0、パージ弁９５、及びパージライン９４が省略されており、それらの代わりに開閉弁９９が設けられている。開閉弁９９は、複数のオフガス容器Ｐ1～ＰNと並列に生成ガスライン３０と接続されている。また、開閉弁９９は、製品ガスライン４０と接続されている。そして、コントローラ９３は、前述の品質管理装置９の処理の流れにおいて、生成ガスライン３０と製品ガスライン４０とを接続する際に、開閉弁９９を開放し、生成ガスライン３０とオフガスライン８０とを接続する際に、開閉弁９９を閉止するように、流路切替器（開閉弁９９、入口弁Ｋ1～ＫN、出口弁Ｊ1～ＪN）を操作する。 In the quality control apparatus 9A, the product gas container P0, the product gas container P0 inlet valve K0, the product gas container P0 outlet valve J0, the purge valve 95, and the purge line 94 of the quality control apparatus 9 according to the above-described embodiment are omitted. Instead, an on-off valve 99 is provided instead. The on-off valve 99 is connected to the generated gas line 30 in parallel with the plurality of off-gas containers P1 to PN. The on-off valve 99 is connected to the product gas line 40. The controller 93 opens the on-off valve 99 when the product gas line 30 and the product gas line 40 are connected in the processing flow of the quality control device 9 described above, and the product gas line 30 and the off-gas line 80 are connected. When the valve is connected, the flow switching device (open / close valve 99, inlet valves K1 to KN, outlet valves J1 to JN) is operated so as to close the open / close valve 99.
（変形例２）
　図６は、変形例２に係るメタン製造装置１００の品質管理装置９Ｂの構成を示す図である。図６に示すように、変形例２に係るメタン製造装置１００では、前述の実施形態に係る品質管理装置９から品質管理装置９Ｂの構成を変更している。 (Modification 2)
FIG. 6 is a diagram illustrating a configuration of a quality control device 9B of the methane production apparatus 100 according to the second modification. As shown in FIG. 6, in the methane production apparatus 100 according to the second modification, the configuration of the quality management apparatus 9B is changed from the quality management apparatus 9 according to the above-described embodiment.
　品質管理装置９Ｂは、メタン濃度計９１と、生成ガスライン３０と接続された三方弁９７と、三方弁９７と、コントローラ９３とを含む。 The quality control device 9B includes a methane concentration meter 91, a three-way valve 97 connected to the product gas line 30, a three-way valve 97, and a controller 93.
　品質管理装置９Ｂでは、前述の実施形態に係る品質管理装置９の複数のガス容器Ｐ0～ＰN、各ガス容器Ｐ0～ＰNの入口に設けられた入口弁Ｋ0～ＫN、各ガス容器Ｐ0～ＰNの出口に設けられた出口弁Ｊ0～ＪN、各ガス容器Ｐ0～ＰNに設けられた圧力計Ｖ0～ＶN、パージ弁９５、及びパージライン９４が省略されており、それらの代わりに三方弁９７が設けられている。三方弁９７は、生成ガスライン３０、製品ガスライン４０、及びオフガスライン８０と接続されており、生成ガスライン３０と接続される流路を製品ガスライン４０とオフガスライン８０との間で切り替える。 In the quality control apparatus 9B, the plurality of gas containers P0 to PN, the inlet valves K0 to KN provided at the inlets of the gas containers P0 to PN, and the gas containers P0 to PN of the quality control apparatus 9 according to the embodiment described above. The outlet valves J0 to JN provided at the outlet, the pressure gauges V0 to VN provided in the gas containers P0 to PN, the purge valve 95, and the purge line 94 are omitted, and a three-way valve 97 is provided instead. It has been. The three-way valve 97 is connected to the product gas line 30, the product gas line 40, and the off gas line 80, and switches the flow path connected to the product gas line 30 between the product gas line 40 and the off gas line 80.
　コントローラ９３は、前述の品質管理装置９の処理の流れにおいて、生成ガスライン３０と製品ガスライン４０とを接続する際に、これらが接続されるように三方弁９７を動作させ、生成ガスライン３０とオフガスライン８０とを接続する際に、これらが接続されるように三方弁９７を動作させる。 The controller 93 operates the three-way valve 97 so that the product gas line 30 and the product gas line 40 are connected when the product gas line 30 and the product gas line 40 are connected in the processing flow of the quality control device 9 described above. And the off-gas line 80 are connected, the three-way valve 97 is operated so that they are connected.
１　　　：連通ライン
２　　　：原料ガス供給ライン
３　　　：メタン分離装置
４　　　：製品ガスタンク
５　　　：リサイクルライン
９，９Ａ，９Ｂ　　　：品質管理装置
１１　　：第１熱交換器
１２　　：水分離器
１３　　：第２熱交換器
２１　　：バッファタンク
２２　　：圧縮機
２３　　：熱交換器
２４　　：水素供給ライン
２５　　：二酸化炭素供給ライン
２６　　：放出弁
２７　　：放出弁制御装置
３０　　：生成ガスライン
３１　　：熱交換器
３２　　：水分離器
４０　　：製品ガスライン
４２　　：水素分離装置
７１　　：水素透過膜
７２　　：メタン流路
７３　　：二酸化炭素流路
９１　　：メタン濃度計
９３　　：コントローラ
９４　　：パージライン
９５　　：パージ弁
９７　　：三方弁
９９　　：開閉弁
１００　：メタン製造装置
Ｒ，Ｒ１，Ｒ２　　　：反応器
Ｔ１，Ｔ２　　：温度センサ 1: Communication line 2: Raw material gas supply line 3: Methane separation device 4: Product gas tank 5: Recycling lines 9, 9A, 9B: Quality control device 11: First heat exchanger 12: Water separator 13: Second heat exchange Unit 21: Buffer tank 22: Compressor 23: Heat exchanger 24: Hydrogen supply line 25: Carbon dioxide supply line 26: Release valve 27: Release valve control device 30: Product gas line 31: Heat exchanger 32: Water separator 40: Product gas line 42: Hydrogen separator 71: Hydrogen permeable membrane 72: Methane flow path 73: Carbon dioxide flow path 91: Methane concentration meter 93: Controller 94: Purge line 95: Purge valve 97: Three-way valve 99: Open / close valve 100: Methane production equipment R, R1, R2: Reactors T1, T2: Temperature sensor

Claims (10)

  1. 　混合した水素と二酸化炭素とを含む原料ガスから製品ガスであるメタンを製造するメタン製造装置であって、
    　メタネーション触媒が収容された反応器と、
    　前記反応器へ前記原料ガスを供給する原料ガス供給ラインと、
    　品質管理装置と、
    　前記反応器と前記品質管理装置とを接続し、前記反応器から出た生成ガスを前記品質管理装置へ送る生成ガスラインと、
    　前記製品ガスを貯える製品ガスタンクと、
    　前記品質管理装置と前記製品ガスタンクとを接続し、前記品質管理装置から出た前記製品ガスを前記製品ガスタンクへ送る製品ガスラインと、
    　前記品質管理装置と接続されたオフガスラインとを備え、
    　前記品質管理装置は、前記生成ガスのメタン濃度を検出するメタン濃度計と、前記生成ガスラインと接続される流路を前記製品ガスラインと前記オフガスラインとの間で切り替える流路切替器と、検出された前記メタン濃度が所定濃度以上のときに前記生成ガスラインと前記製品ガスラインとが接続され、検出された前記メタン濃度が前記所定濃度未満のときに前記生成ガスラインと前記オフガスラインとが接続されるように、前記流路切替器を動作させるコントローラとを、有する、
    メタン製造装置。     A methane production apparatus for producing methane, which is a product gas, from a raw material gas containing mixed hydrogen and carbon dioxide,
    A reactor containing a methanation catalyst;
    A source gas supply line for supplying the source gas to the reactor;
    A quality control device,
    A product gas line that connects the reactor and the quality control device, and sends a product gas from the reactor to the quality control device;
    A product gas tank for storing the product gas;
    A product gas line for connecting the quality control device and the product gas tank, and sending the product gas from the quality control device to the product gas tank;
    An off-gas line connected to the quality control device,
    The quality control device includes a methane concentration meter that detects a methane concentration of the product gas, a flow channel switch that switches a flow channel connected to the product gas line between the product gas line and the off-gas line, The generated gas line and the product gas line are connected when the detected methane concentration is equal to or higher than a predetermined concentration, and when the detected methane concentration is lower than the predetermined concentration, the generated gas line and the off-gas line are connected. A controller that operates the flow path switching device so that
    Methane production equipment.
  2. 　前記オフガスラインの下流側端部が、前記原料ガス供給ラインと接続されている、
    請求項１に記載のメタン製造装置。     The downstream end of the off gas line is connected to the source gas supply line,
    The methane production apparatus according to claim 1.
  3. 　前記品質管理装置は、前記生成ガスラインに並列に接続された複数のオフガス容器を備え、前記複数のオフガス容器に前記メタン濃度が前記所定濃度未満のガスを貯溜する、
    請求項１又は２に記載のメタン製造装置。     The quality control device includes a plurality of off-gas containers connected in parallel to the product gas line, and stores the gas having a methane concentration less than the predetermined concentration in the plurality of off-gas containers.
    The methane production apparatus according to claim 1 or 2.
  4. 　前記製品ガスラインに設けられた水素分離装置を更に備え、
    　前記水素分離装置が、水素透過膜と、前記水素透過膜を介して一側に設けられた前記メタンが通るメタン流路と、前記水素透過膜を介して他側に設けられた前記水素と混合される前の前記二酸化炭素が通る二酸化炭素流路とを有する、
    請求項１～３のいずれか一項に記載のメタン製造装置。     A hydrogen separator provided in the product gas line;
    The hydrogen separator is mixed with a hydrogen permeable membrane, a methane passage through which the methane is provided on one side via the hydrogen permeable membrane, and the hydrogen provided on the other side via the hydrogen permeable membrane. A carbon dioxide flow path through which the carbon dioxide before being passed,
    The methane production apparatus according to any one of claims 1 to 3.
  5. 　前記反応器の前記触媒の温度を検出する温度センサと、
    　前記原料ガス供給ラインに設けられた、バッファタンク、前記バッファタンクへ前記水素を供給する水素供給ライン、及び、前記バッファタンクへ前記二酸化炭素を供給する二酸化炭素供給ラインと、
    　前記二酸化炭素供給ラインに設けられた放出弁と、
    　検出された前記触媒の温度に基づいて、前記触媒の温度が所定温度以上のときに前記二酸化炭素供給ラインを通る前記二酸化炭素の少なくとも一部が系外へ放出され、前記触媒の温度が前記所定温度未満のときに前記放出弁が閉じられるように、前記放出弁を動作させる放出弁制御装置とを、更に備える、
    請求項１～４のいずれか一項に記載のメタン製造装置。     A temperature sensor for detecting the temperature of the catalyst in the reactor;
    A buffer tank provided in the source gas supply line, a hydrogen supply line for supplying the hydrogen to the buffer tank, and a carbon dioxide supply line for supplying the carbon dioxide to the buffer tank;
    A discharge valve provided in the carbon dioxide supply line;
    Based on the detected temperature of the catalyst, at least a part of the carbon dioxide passing through the carbon dioxide supply line is released out of the system when the temperature of the catalyst is equal to or higher than a predetermined temperature, and the temperature of the catalyst is the predetermined temperature. A discharge valve control device for operating the discharge valve so that the discharge valve is closed when the temperature is lower than the temperature;
    The methane production apparatus according to any one of claims 1 to 4.
  6. 　前記反応器が、連通ラインで直列的に接続された複数の反応器を含む、
    請求項１～５のいずれか一項に記載のメタン製造装置。     The reactor includes a plurality of reactors connected in series by a communication line;
    The methane production apparatus according to any one of claims 1 to 5.
  7. 　水素と二酸化炭素とを混合して原料ガスを調製する工程と、
    　前記原料ガス中の前記水素及び前記二酸化炭素をメタネーション触媒の存在下で反応させてメタン及び水を生成する工程と、
    　生成した前記メタン及び水、並びに、未反応の前記原料ガスを含む生成ガスのメタン濃度を検出する工程と、
    　検出された前記生成ガスのメタン濃度が所定濃度以上のときに前記生成ガスを製品ガスタンクへ送り、検出された前記生成ガスのメタン濃度が前記所定濃度未満のときに前記生成ガスをオフガスラインへ送る工程と、
    を含むメタン製造方法。     A step of preparing a raw material gas by mixing hydrogen and carbon dioxide;
    Reacting the hydrogen and the carbon dioxide in the source gas in the presence of a methanation catalyst to produce methane and water;
    Detecting the methane concentration of the produced gas containing the produced methane and water and the unreacted raw material gas;
    When the detected methane concentration of the generated gas is equal to or higher than a predetermined concentration, the generated gas is sent to a product gas tank, and when the detected methane concentration of the generated gas is lower than the predetermined concentration, the generated gas is sent to an off-gas line. Process,
    A method for producing methane comprising:
  8. 　前記生成ガスを前記オフガスラインへ送る工程が、前記生成ガスを前記原料ガスに混入させることを含む、
    請求項７に記載のメタン製造方法。     Sending the product gas to the off-gas line includes mixing the product gas into the source gas;
    The method for producing methane according to claim 7.
  9. 　前記生成ガスを前記オフガスラインへ送る工程が、前記生成ガスを複数のガス容器に送ることを含む、
    請求項７又は８に記載のメタン製造方法。     Sending the product gas to the off-gas line includes sending the product gas to a plurality of gas containers;
    The method for producing methane according to claim 7 or 8.
  10. 　前記生成ガスを前記製品ガスタンクへ送る工程が、前記生成ガスから分離した前記メタンと前記水素と混合される前の前記二酸化炭素との水素分圧差を利用して、水素透過膜を用いて前記メタンからそれに含まれる前記水素を除去することを含む、
    請求項７～９のいずれか一項に記載のメタン製造方法。     The step of sending the product gas to the product gas tank uses the hydrogen partial pressure difference between the methane separated from the product gas and the carbon dioxide before being mixed with the hydrogen, and using the hydrogen permeable membrane, the methane Removing the hydrogen contained therein from
    The method for producing methane according to any one of claims 7 to 9.
PCT/JP2019/009164 2018-03-13 2019-03-07 Methane production device and method WO2019176745A1 (en)

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