WO2017134940A1 - Steam reforming system and power generation system - Google Patents

Steam reforming system and power generation system Download PDF

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Publication number
WO2017134940A1
WO2017134940A1 PCT/JP2016/087371 JP2016087371W WO2017134940A1 WO 2017134940 A1 WO2017134940 A1 WO 2017134940A1 JP 2016087371 W JP2016087371 W JP 2016087371W WO 2017134940 A1 WO2017134940 A1 WO 2017134940A1
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Prior art keywords
gas
reforming
hydrogen
steam
tank
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PCT/JP2016/087371
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French (fr)
Japanese (ja)
Inventor
五三實 大岡
岡田　治
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株式会社ルネッサンス・エナジー・リサーチ
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Priority to JP2017512412A priority Critical patent/JP6125140B1/en
Publication of WO2017134940A1 publication Critical patent/WO2017134940A1/en

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    • 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
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
    • C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
    • C01B3/38—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts
    • 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
    • C01B3/56—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification by contacting with solids; Regeneration of used solids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/06—Combination of fuel cells with means for production of reactants or for treatment of residues
    • H01M8/0606—Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants
    • H01M8/0612—Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants from carbon-containing material
    • 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
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • the present invention relates to a steam reforming system for producing hydrogen used for fuel cells and metal processing by reforming a hydrocarbon-based gas, and a power generation system including the steam reforming system. About.
  • FCVs fuel cell vehicles
  • FIG. 10 schematically shows a configuration example of a conventional hydrogen production system 100 constituting a satellite hydrogen supply facility.
  • FIG. 10 shows the main equipment constituting the hydrogen production system 100 and the material flow between the equipment.
  • a conventional hydrogen production system 100 shown in FIG. 10 includes a raw material compressor 101, a desulfurizer 102, a feed water preheater 103, a waste heat recovery boiler 104, a reforming furnace 105, a reforming pipe 106, a raw material preheater 107, and a superheater. 108, a burner 109, an air preheater 110, a CO converter 111, a gas cooler 112, a PSA hydrogen separator 113, and the like.
  • a raw material gas such as city gas (13A gas) mainly composed of methane is compressed by the raw material compressor 101 and preheated by the raw material preheater 107 provided in the reforming furnace 105.
  • the sulfur compound contained in the city gas is removed by the desulfurizer 102 and supplied to the reforming pipe 106.
  • the feed water preheater 103 the water preheated by exchanging heat with the high-temperature modified gas generated in the CO converter 111 is evaporated by heat exchange with the heat generated in the CO modification reaction of the CO converter 111,
  • the material gas is superheated in the superheater 108 in the quality furnace 105 and merged with the desulfurized raw material gas and supplied to the reforming pipe 106.
  • Part of the raw material gas is supplied as fuel gas to the burner 109, and the combustion air is preheated by heat exchange with the waste heat of the combustion exhaust gas discharged from the reforming furnace 105 by the air preheater 110 and supplied to the burner 109. Is done.
  • the raw material gas and water vapor supplied to the reforming tube 106 undergo a reforming reaction by heating by the burner 109, and a reformed gas containing hydrogen and carbon monoxide is generated.
  • the CO converter 111 carbon monoxide contained in the reformed gas is converted into carbon dioxide, and a modified gas having a reduced CO concentration is generated.
  • the PSA hydrogen separator 113 After the denatured gas is cooled by the feed water preheater 103 and the gas cooler 112, the PSA hydrogen separator 113 adsorbs and removes gas other than hydrogen to produce product hydrogen having an increased concentration of hydrogen. Gas other than hydrogen (off-gas) recovered by the PSA hydrogen separator 113 is supplied to the burner 109 as combustion gas.
  • the material balance and heat balance are calculated according to the material flow as shown in FIG. 10, and the heat loss generated in the process is determined with reference to past experience. There were many decisions.
  • an energy balance diagram as shown in FIG. 11 is often used for the material flow shown in FIG. Since improvement of hydrogen gasification efficiency means a reduction in heat loss, it is important to study the essence of heat loss, but it is difficult to grasp the state in detail from the heat loss portion shown in FIG. is there.
  • Patent Document 1 the present applicant has arranged a reformer and a burner constituting the hydrogen production system in the upper stage, and a CO converter and a desulfurizer are arranged in the lower stage.
  • the present invention has been made in view of the above-mentioned problems, and its purpose is to perform steam reforming capable of effectively suppressing heat loss and achieving hydrogen gasification efficiency of 80% or more, preferably 90% or more. To provide a system.
  • Fig. 12 shows the system boundary for hydrogen production and shows the input / output status of substances.
  • the materials to be input are raw material gas, process water to be process steam, and fuel and combustion air, and the materials to be output are undecomposed of product hydrogen and process steam that have not reacted. Steam and combustion exhaust gas.
  • the hydrogen production system as a whole is an exothermic system and involves dissipated heat.
  • FIG. 12 when looking at the change in process water, most of it becomes product hydrogen gas, and the remaining hydrogen gas becomes off-gas in PSA separation and burns to become water vapor in the exhaust gas.
  • the temperature / enthalpy diagram of each fluid is drawn as a heat loss analysis diagram, By quantitatively grasping the distribution of heat loss and checking the temperature difference and pinch point between fluids, it is possible to check the operation and optimize the system design.
  • the portions with large heat loss are the combustion exhaust gas loss, the heat radiation loss on the combustion gas side, and the exhaust heat loss of the process fluid.
  • Combustion exhaust gas loss is not only due to process heating, but also increases the amount of combustion to bear the overall heat dissipation, the hydrogen content in the off-gas used as fuel burns and contains a large amount of water vapor, and the CO 2 in the off-gas is large. Inclusion is a factor. Therefore, when the hydrogen recovery rate in the PSA separation increases, the heat loss slightly decreases, but the ratio is larger than the exhaust gas loss of a normal boiler or the like.
  • the heat release on the combustion gas side is normally considered in the process design together with the heat release on the reformed gas side generated from the same heating source.
  • the ratio of the total heat release amount of the plant to the calorific value (HHV) of the burning fuel is 26.1%. This value is larger than 2 to 5% for package boilers and large boilers, but is 15 to 20% even for large hydrogen production plants.
  • the reason is that the furnace body of the high-temperature reforming furnace is large and is derived from the structure of the equipment and piping in the high-temperature part, so there is much room for improvement.
  • heat loss reduction for improving hydrogen gasification efficiency includes 1) reduction of combustion exhaust gas loss, 2) reduction of heat dissipation loss, 3) reduction of undecomposed steam, and 4) hydrogen recovery rate in PSA separation. Measures such as improvement are effective.
  • Measures 1) to 4) above include measures by devising equipment and system design and measures by reviewing operating conditions. As will be described later, it may be necessary to take measures on the device side to deal with side effects associated with the review of operating conditions.
  • the reduction of the combustion air ratio and the reduction of the exhaust gas temperature are considered as basic measures.
  • the former is performed mainly by reviewing operating conditions, and the latter is performed by devising equipment and system design such as increasing the efficiency of waste heat recovery.
  • ⁇ ⁇ Reduction of undecomposed steam is basically done by reviewing the operating conditions such as setting the reforming temperature high within the allowable range and supplying the raw material gas and process steam at low S / C.
  • the operating conditions such as setting the reforming temperature high within the allowable range and supplying the raw material gas and process steam at low S / C.
  • carbon generation due to thermal decomposition of hydrocarbons in the steam reforming reaction becomes significant, and an increase in the CO concentration in the shift gas output from the CO shift converter becomes a problem. Therefore, in order to reduce the undecomposed steam, it is necessary to separately deal with the above-mentioned problem due to low S / C on the device and system side.
  • Improvement of hydrogen recovery rate in PSA separation will be implemented by equipment and system design such as high performance adsorbent and high recovery rate by improving pressure control of adsorption tank.
  • equipment and system design such as high performance adsorbent and high recovery rate by improving pressure control of adsorption tank.
  • a chemical adsorbent having a high adsorption capability for CO as a high-performance adsorbent, it is possible to cope with an increase in CO concentration caused by low S / C as well as an improvement in the hydrogen recovery rate.
  • Possible countermeasures against carbon generation due to low S / C include installing a desulfurizer in front of the reformer, adding an appropriate amount of hydrogen to the raw material gas, and installing a pre-reformer that reforms hydrocarbons at low temperatures. It is done. However, it is desirable that countermeasures based on these device and system design ideas can be implemented so as to contribute to the other countermeasures described above, if possible, so as not to hinder the other countermeasures described above.
  • a plurality of reforming pipes that generate a reformed gas containing at least hydrogen and carbon monoxide by reacting a raw material gas containing hydrocarbons with steam are surrounded by a heat insulating structure.
  • a reformer formed by connecting and connecting in parallel with each other in a cylindrical reforming furnace, a steam generator for generating steam to be supplied to the reformer, and the reformed gas
  • the carbon monoxide contained in the gas is reacted with water vapor to be converted into carbon dioxide, and a reformer for generating a transformed gas having a reduced concentration of carbon monoxide from the reformed gas, and burning a fuel gas
  • a combustor for supplying heat into the reforming furnace,
  • Each of the reforming pipes is coaxially provided with an outer pipe whose both ends are closed, and an inner pipe which is accommodated in the outer pipe and whose one end is closed and the other end is opened, and an inlet is provided on one end side of the outer pipe.
  • An outlet is provided on one end side of the inner tube, and an outer channel formed between the outer tube and the inner tube and an inner channel formed in the inner tube are connected to the other end in the outer tube.
  • at least the outer flow path is filled with a reforming catalyst.
  • the combustor is provided in the reforming furnace or on the other end side of the outer tube of the furnace wall of the reforming furnace, the reformer and the tubular transformer are adjacent to each other, and
  • the first feature is that the plurality of reforming tubes and the cylindrical transformer are installed in one cylindrical accommodation space with the axial directions thereof being parallel to each other.
  • the heat of combustion of the fuel outside the outer pipe and the high temperature passing through the inside of the inner pipe against the steam reforming reaction that is an endothermic reaction in the outer flow path Since it is efficiently heated from the reformed gas, the reforming temperature can be easily increased within an allowable range, and furthermore, the area of the tube wall used for heat exchange can be increased, so that the heat exchange efficiency can be increased. Thereby, reduction of heat dissipation loss and reduction of undecomposed steam can be achieved.
  • the combustor is provided in the reforming furnace or on the other end side of the outer pipe of the furnace wall of the reforming furnace, the high-temperature combustion gas generated by the combustor and the outer wall surface of the outer pipe are reformed.
  • the combustion gas flow path between the inner wall surfaces of the furnace flows from the other end side of the outer pipe of the flow path toward the one end side.
  • the heat of the combustion gas is absorbed by the tube wall of the outer tube, and the combustion gas temperature decreases from the other end side of the outer tube toward the one end side.
  • the other end side of the combustion gas passage is about 1000 ° C. and the other end side is lowered to about 500 ° C.
  • the heat transfer in the reforming furnace is mainly radiant heat transfer, and the radiant heat transfer follows the Stefan-Boltzmann law that the difference is the fourth power of the absolute temperature.
  • the amount of heat transfer per unit heat transfer area (heat flux) increases, the temperature is low at one end of the outer tube, and the amount of heat transfer per unit heat transfer area (heat flux) decreases. Therefore, a partial region near one end side (inlet side) in the outer channel becomes a moderate temperature rise of the gas to be processed, functions as a pre-reformer, and causes carbon precipitation due to low S / C operation. Can be suppressed.
  • the temperature of the reformed gas flowing through the inner flow path is also reduced by the heat of the reformed gas being absorbed by the tube wall of the inner tube from the other end side of the inner tube toward the one end side, like the combustion gas. .
  • the other end side of the combustion gas passage is about 860 ° C. and the other end side is lowered to about 450 ° C. Therefore, the change in the temperature of the reformed gas flowing through the inner flow path is similar to the change in the combustion gas temperature. Becomes gentle, functions as a pre-reformer, and contributes to the suppression of carbon deposition due to low S / C operation. Further, since the reformed gas temperature at the reforming pipe outlet is lowered, there is an advantage that the connection of the piping flange becomes easy.
  • the reformer and the transformer can be integrated and accommodated in the accommodation space including the piping connecting the two, the outside heat radiation area of the high temperature equipment can be reduced, and the heat radiation loss can be reduced.
  • each cross-sectional area of the outer pipe and the outer flow path in a plane perpendicular to the axis of the reforming pipe is a central portion in the axial direction.
  • the second feature is that the one end side of the outer tube and the inner tube is larger than the other end side of the central portion.
  • the volume of the region that can function as a pre-reformer on the inlet side of the outer flow path can be increased and the residence time of the gas to be processed can be increased.
  • the rapid temperature rise is suppressed, and the structure becomes more suitable as a pre-reformer.
  • the cross-sectional area of the outer pipe that is, the sum of the cross-sectional area of the outer flow path and the cross-sectional area of the inner pipe
  • the surface area of the outer wall surface of the outer pipe increases.
  • the combustion gas temperature is as compared with the case where the cross-sectional area of the outer pipe is constant (that is, straight pipe).
  • the outer tube is more remarkably lowered from the other end side to the one end side, and the structure becomes more suitable as a pre-reformer.
  • the cross-sectional area of the outer pipe is larger on one end side than the central part, the cross-sectional area between the inner wall of the reforming furnace and the outer wall of the outer pipe in that part becomes smaller, and the outer pipe in the combustion gas flow path
  • the flow velocity of the combustion gas flowing from the end side toward the one end side becomes larger on the one end side of the outer tube, and the convective heat transfer amount of the combustion gas increases.
  • the radiant heat transfer amount of the combustion gas is reduced at one end side of the outer pipe in the combustion gas flow path. Therefore, the heat transfer amount per unit heat transfer area ( Heat flux) rises slightly.
  • the increase in heat flux due to convective heat transfer is not so large as to significantly affect the carbon generation near the inlet of the outer channel.
  • the steam reforming system according to the present invention has an amount of steam supplied from the steam generator to the reformer with respect to the amount of carbon in the raw material gas supplied to the reformer.
  • a third feature is that the amount of carbon and the amount of water vapor supplied to the reformer are adjusted so that the molar ratio is 1.7 or more and 2.4 or less. Thereby, reduction of undecomposed steam can be achieved.
  • a steam reforming system includes, in addition to any of the above features, a desulfurizer that includes a concentric cylindrical container in which an outer tank portion surrounds the outer periphery of an inner tank portion, and removes sulfur components contained in the raw material gas.
  • the transformer is formed in one of the outer tank part and the inner tank part and the other, and is configured to be able to exchange heat with each other, and the reformer and the concentric cylindrical container are in the storage space,
  • a fourth feature is that the plurality of reforming tubes and the concentric cylindrical containers are installed adjacent to each other with their axial directions parallel to each other.
  • the generation of carbon due to low S / C is suppressed by providing the desulfurizer. Furthermore, since the desulfurizer and the transformer are configured so as to be able to exchange heat with each other, it is possible to reduce heat dissipation loss, suppress an increase in the shift gas temperature, and stabilize the CO shift reaction temperature. Furthermore, since the desulfurizer and the transformer are configured in one concentric cylindrical container, similar to the first feature, the reformer, the transformer, and the desulfurizer are also included, including piping that communicates between each part. Since it can be accommodated in the housing space, the outside air heat radiation area of the high temperature equipment can be reduced, and the heat radiation loss can be reduced.
  • the steam reforming system utilizes the heat generated in the shift reaction of the shift transformer as at least part of the steam generator in the shift converter.
  • a fifth feature is that a first steam generator for generating water vapor to be supplied to the mass device is provided.
  • the first steam generator and the transformer are configured to be able to exchange heat with each other, it is possible to reduce heat dissipation loss and suppress an increase in the temperature of the transformed gas. It is possible to stabilize the CO shift reaction temperature. Furthermore, by adjusting the amount of steam generated by the first steam generator, the amount of process steam generated can be optimized and low S / C can be realized.
  • the steam reforming system includes at least one of the steam generators in the middle of an exhaust path for exhausting combustion exhaust gas generated in the reforming furnace to the outside of the reforming furnace.
  • a second steam generator that generates steam to be supplied to the reformer using waste heat of the combustion exhaust gas, and the second steam generator is placed in the housing space,
  • a sixth feature is that the reformer is formed along a side surface of the furnace wall portion of the reforming furnace.
  • combustion exhaust gas loss can be reduced. Also, by forming the second steam generator along the side surface of the reformer furnace wall, the heat exchange surface area is reduced compared to the case where the second steam generator is configured with a dedicated heat exchanger. It is possible to further reduce the combustion exhaust gas loss. Furthermore, by adjusting the amount of steam generated by the second steam generator, the amount of process steam generated can be optimized, and low S / C can be realized. Further, when both the first steam generator and the second steam generator are provided, the temperature control of the CO shift reaction is optimized by adjusting the distribution of the steam generation amount in the first and second steam generators. Therefore, optimization of the amount of process steam generated can be realized more easily, and low S / C and stable operation control can be realized.
  • the steam reforming system according to the present invention is provided with a steel plate outer plate in contact with the outer surface of the heat insulating structure of the reforming furnace, and can conduct heat to the steel plate outer plate.
  • a thin tube coil is provided in contact with the steel plate, and water supplied to the second steam generator is transmitted from the heat insulating structure of the reforming furnace to the steel plate outer plate by the steel plate outer plate and the thin tube coil.
  • a seventh feature is that a feed water preheater that preheats using the generated heat is formed.
  • the steel plate outer plate can suppress the circulation residence heat loss of the combustion gas in the reforming furnace and can effectively recover the waste heat of the combustion exhaust gas. Reduction of combustion exhaust gas loss can be achieved. Further, by forming the feed water preheater in contact with the steel plate outer plate, sufficient heat insulating performance can be realized without increasing the thickness of the heat insulating material covering the steel plate outer plate.
  • the steam reforming system is configured to dispose the waste heat of the combustion exhaust gas in the middle of an exhaust path for exhausting the combustion exhaust gas generated in the reforming furnace to the outside of the reforming furnace.
  • a gas preheater and an air preheater for preheating the fuel gas and combustion air supplied to the combustor, and the gas preheater and the air preheater are placed in the housing space.
  • An eighth feature is that the heat insulating structure is formed along the side surface of the quality furnace.
  • combustion exhaust gas loss can be reduced.
  • the gas preheater and air preheater along the side surface of the heat insulating structure of the reforming furnace, compared with the case where the gas preheater and air preheater are configured with dedicated heat exchangers, The exchange surface area can be reduced and combustion exhaust gas loss can be further reduced.
  • the steam reforming system according to the present invention absorbs and removes a gas other than hydrogen contained in the modified gas, and generates product hydrogen having an increased hydrogen concentration from the modified gas.
  • a ninth feature is that a separation device is provided outside the accommodation space.
  • a high-purity product hydrogen gas from which gases other than hydrogen such as CO, CO 2 , and CH 4 contained in the modified gas are removed can be obtained. Further, the gas other than the removed hydrogen (off-gas) is recovered and reused as a fuel gas, so that the thermal efficiency is improved.
  • each of the plurality of adsorption tanks provided in the PSA separation apparatus chemically adsorbs carbon monoxide contained in the metamorphic gas.
  • the tenth feature is to provide an agent.
  • the chemical adsorbent since the chemical adsorbent has a higher adsorption capacity for CO as compared with a physical adsorbent, the volume occupied by the adsorbent can be reduced. The amount of hydrogen recovered can be reduced. Moreover, the heat loss resulting from offgas is reduced by reducing the amount of offgas.
  • the PSA separation apparatus includes three adsorption tanks, a vacuum pump, and a supplementary pressure pump, and the vacuum pump and the supplementary pressure pump
  • the same vacuum pump is also used, or each pump is composed of individual pumps, and one cycle in which the first tank among the three tanks is subjected to the adsorption process is composed of four steps.
  • the PSA separator In the first step, in order to equalize the internal pressure of the second tank and the third tank among the three adsorption tanks, the second tank and the third tank are communicated with each other, and the second tank The pressure in the third tank, In the second step, the inside of the tanks of the second and third tanks are communicated via the pressure pump, the second tank is further depressurized, the third tank is further pressurized, In the third step, the third tank is pressurized using a part of the product hydrogen, and the gas other than the hydrogen adsorbed in the second tank is vacuum desorbed by operating the vacuum pump.
  • the eleventh feature is that it is configured.
  • the purge is performed through the second pressure compensation process and the third process vacuum desorption process, so that it is used for desorption and purge in the conventional PSA hydrogen separation.
  • the amount of hydrogen used can be greatly reduced, and the hydrogen recovery rate can be improved.
  • a power generation system includes a hydrogen production system including a steam reforming system having any of the above characteristics, and a power generation device that consumes hydrogen generated by the hydrogen production system to generate power, and
  • the first feature is that the hydrogen gasification efficiency of the system is 90% or more.
  • the power generation system having the first feature described above by adopting a polymer electrolyte fuel cell (PEFC) or the like whose power generation efficiency has been improved to 50% or more in recent years, the power generation system as a whole is extremely high. Power generation efficiency can be obtained. For example, assuming that the power generation efficiency of the power generation device is 50% and the hydrogen gasification efficiency of the hydrogen production system is 90%, considering the orthogonal transformation efficiency and private power consumption, the power transmission end efficiency (HHV) is about 44%. The power generation efficiency is comparable to natural gas gas turbine combined cycle (GTCC) power generation.
  • GTCC natural gas gas turbine combined cycle
  • the hydrogen production system constitutes a hydrogen supply facility in a hydrogen supply base for vehicles using hydrogen as a fuel, and the power generation device includes the hydrogen supply base.
  • a second feature is that a power supply facility for supplying electric power to the electric vehicle is provided.
  • the generated power of the power generation device is supplied to the electric vehicle, so that a high operation rate is achieved. realizable.
  • the generated power can be used for compressed hydrogen power and can be sold externally.
  • heat loss can be effectively suppressed, low S / C operation with suppressed carbon generation is possible, and hydrogen gasification efficiency of 80% or more, preferably 90% or more is achieved. Can be achieved.
  • FIG. 2 is a development view schematically showing the schematic configuration of the waste heat recovery equipment provided in the reforming furnace of the steam reforming system shown in FIG. Schematic configuration of the PSA hydrogen separator of the steam reforming system shown in FIG.
  • FIG. 1 a configuration diagram schematically showing the open / close state of the valve during one cycle
  • Table comparing the expected operating results of the steam reforming system according to the present invention A table comparing the expected operating results of steam reforming systems by conditions
  • a bar graph showing the composition ratio of various losses and hydrogen gasification efficiency in the predicted operating results by conditions shown in FIG.
  • Schematic diagram showing the schematic configuration of a conventional hydrogen production system
  • Energy balance diagram showing a heat balance example of the conventional hydrogen production system shown in FIG. Diagram showing the movement of substances in hydrogen production
  • Heat loss analysis diagram showing an example of heat loss distribution according to the relationship between the temperature of the fluid and the enthalpy of the combustion gas in the conventional hydrogen production system shown in FIG.
  • the steam reforming system 1 includes a raw material compressor 11, a desulfurizer 12, a first feed water preheater 13, a second feed water preheater 14, and a first steam generator. 15, second steam generator 16, reforming furnace 17, reforming pipe 18, burner 19 (corresponding to a combustor), gas preheater 20, air preheater 21, CO converter 22, gas cooler 23, drain separation And a PSA hydrogen separator 25 and the like.
  • the components between the devices constituting the steam reforming system 1 and the devices raw gas, fuel gas, pure water, steam, combustion air, combustion exhaust gas, reformed gas, modified gas, product hydrogen gas, off gas, This shows the flow of hydrogen for desulfurization.
  • FIG. 2 shows a desulfurizer 12, a first feed water preheater 13, a second feed water preheater 14, a first steam generator 15, and a second steam generator 16 in a cylindrical housing space 10 indicated by a two-dot chain line.
  • Is shown. 2A shows the assembly structure in a cross section perpendicular to the axis of the cylindrical accommodation space 10, and FIG.
  • FIG. 2B shows the assembly structure in a cross section AA ′ passing through the coaxial core.
  • FIG. 3 is a diagram schematically showing an assembly structure in which the reforming pipe 18 is constituted by a coaxial double pipe of an outer pipe 26 and an inner pipe 27, and a schematic cross section in a cross section passing through the axis of the reforming pipe 18.
  • the upper side in FIGS. 2B and 3 is the “one end side” of the reforming furnace 17, the reforming pipe 18 (the outer pipe 26 and the inner pipe 27), and the cylindrical housing space 10.
  • the lower side corresponds to the “other end side” of the reforming furnace 17, the reforming pipe 18 (the outer pipe 26 and the inner pipe 27), and the cylindrical accommodation space 10.
  • the reforming furnace 17 is formed in a portion excluding a substantially fan-shaped surplus space in the accommodation space 10 in a plane perpendicular to the axis of the accommodation space 10.
  • the surplus space is a part of the accommodation space 10 including an arc part of about one quarter of the outer periphery of the accommodation space 10.
  • a desulfurizer 12, a first feed water preheater 13, a first steam generator 15, and a CO converter 22 are installed.
  • the reforming furnace 17 includes five reforming pipes in a reforming furnace surrounded by a heat insulating structure (furnace wall, furnace top, furnace bottom) made of a heat insulating material such as refractory bricks, with its side surface, upper surface and lower surface surrounded. 18 is housed.
  • the five reforming tubes 18 have the same structure, shape and dimensions. In FIG. 2A, the portions where the five reforming pipes 18 are simply displayed with different pipe diameters show cross sections having different pipe diameters.
  • the five reforming tubes 18 are inserted into the reforming furnace from five openings provided on the upper surface of the heat insulating structure of the reforming furnace 17.
  • the inlets of the reforming pipes 18 are connected to and communicated with each other on the upper side of the furnace top portion through an inlet pipe and an outlet through an outlet pipe, respectively.
  • the top view of the space in the reforming furnace has a substantially “C” shape (a shape in which about a quarter of the donut is cut out), and follows the arc-shaped center line of this “C” shape.
  • five reforming pipes 18 are arranged.
  • the burner 19 is provided so as to penetrate the lower end portion of the furnace wall portion of the reforming furnace 17, and the combustion gas generated by the combustion of the fuel gas by the burner 19 is provided for each outer pipe of the five reforming pipes 18.
  • a combustion gas passage formed between the outer wall surface of 26 and the inner wall surface of the furnace wall portion of the reforming furnace 17 is configured to flow from the lower side toward the upper side.
  • the burner 19 may be installed not at the lower end of the furnace wall but at the furnace bottom in the reforming furnace 17.
  • each reformer tube 18 is formed by blocking the lower end of the outer tube 26 with a spherical lid member 28.
  • the bottom surface of the lid member 28 is in contact with and supported by a spherical recess formed at the bottom.
  • the outer surface of the upper end of the outer tube 26 and the lower surface of the flange portion are in airtight contact with the inner surface of the opening and the upper surface of the outer periphery, and the upper opening of the outer tube 26 is partially blocked by a spherical lid member 29.
  • the upper lid member 29 is provided with an inlet pipe 32 that forms an inlet for supplying a mixed gas of raw material gas and water vapor to the outer flow path 30 between the outer pipe 26 and the inner pipe 27.
  • the inlet pipe 32 of each reforming pipe 18 is connected to a common inlet pipe 36.
  • An inner flow path 31 is formed inside the inner tube 27. As shown in FIGS. 2B and 3, the lower end of the inner tube 27 is opened, and the outer flow is passed through the lower space 34 between the opening and the outer flow path 30 in the outer tube 26 and the lid member 28. The path 30 and the inner flow path 31 communicate with each other.
  • the upper opening of the inner tube 27 is shielded by a flat lid member 35, and the reformed gas generated by reforming the mixed gas while passing through the outer flow path 30 is generated in the upper lid member 35. Is provided through the inner flow path 31 to the outside.
  • the outlet pipe 33 projects from the inner flow path 31 through the lid member 35 and the lid member 29 to the outside.
  • the outlet pipe 33 of each reforming pipe 18 is connected to a common outlet pipe 37.
  • an inlet pipe 32 and an outlet pipe 33 are provided on the upper side (one end side) of each reforming pipe 18, and a gas to be processed (mixed gas) sent from the inlet pipe 32 to the outer flow path 30. Passes through the outer flow path 30 downward and is reformed in the outer flow path 30 and the lower space 34, and the reformed gas after reforming reverses the flow direction in the lower space 34, It passes through the flow path 31 upward and is sent from the outlet pipe 33 to the outlet pipe 37.
  • the combustion gas flows through the combustion gas flow path between the outer wall of each outer pipe 26 and the inner wall surface of the reforming furnace 17 from the lower side to the upper side.
  • Heat is absorbed by the tube wall of the outer tube 26, and the combustion gas temperature decreases from the lower side toward the upper side.
  • the heat of the reformed gas is absorbed by the tube wall of the inner tube 27, and the reformed gas temperature decreases from the lower side toward the upper side.
  • the heat transfer amount (heat flux) per unit heat transfer area that passes through the outer pipe 26 and the inner pipe 27 and is conducted into the outer flow path 30 decreases toward the upper side.
  • the temperature rise of the gas to be treated becomes gradual, functions as a pre-reformer, and can suppress carbon precipitation caused by low S / C operation.
  • the outer diameters of the outer tube 26 and the inner tube 27 are expanded toward the upper side at a substantially central portion in the axial direction, and the upper side of the expanded diameter portion is larger than the lower side of the expanded diameter portion. It has become.
  • the outer diameters of the outer pipe 26 and the inner pipe 27 in the upper portion are about 318 mm and about 216 mm, respectively.
  • the thickness of the tube wall is about 10 mm and about 2.8 mm, respectively.
  • the outer diameters of the outer tube 26 and the inner tube 27 in the lower part are about 216 mm and about 140 mm, respectively, and the thickness of the tube wall is about 8 mm and about 2.8 mm, respectively. Accordingly, the outer tube 26 and the inner tube 27 are each shaped like an inverted beer bottle.
  • the structure of the reforming pipe 18 in the present embodiment is referred to as a “reverse bottle type double pipe structure” for convenience.
  • the scale in the vertical direction is displayed by being greatly compressed compared to the horizontal direction. It is very different from dimensional ratio.
  • the cylindrical accommodation space 10 has a diameter of 2 m and a height of 3.15 m.
  • the volume of the region functioning as a pre-reformer on the inlet side of the outer flow path 30 can be increased, and the residence time of the gas to be processed can be increased.
  • the rapid increase in temperature of the gas to be processed is suppressed, and the structure becomes more suitable as a pre-reformer.
  • the combustion gas flow path between the outer wall of each outer pipe 26 and the inner wall surface of the reforming furnace 17 is narrower on the upper side than the above-mentioned enlarged diameter portion.
  • the flow velocity of the combustion gas flowing in the direction increases at the narrowed portion, and the convective heat transfer amount of the combustion gas increases.
  • the heat transfer in the reforming furnace 17 is mainly radiant heat transfer, the effect of suppressing carbon deposition is not impaired by the increase in the amount of convective heat transfer.
  • the reforming catalyst is filled in the outer flow path 30 and the lower space 34, and the inner flow path 31 is filled with inert particles such as alumina.
  • the lower space 34 may not be filled with the reforming catalyst, and a part of the lower end portion of the inner flow path 31 may be filled with a small amount of the reforming catalyst.
  • the reforming catalyst use of a Ru-based catalyst, a Ni-based catalyst, or the like is assumed, but is not limited thereto.
  • the desulfurizer 12, the CO converter 22, the first feed water preheater 13, and the first steam generator 15 will be described with reference to FIG.
  • the desulfurizer 12, the CO converter 22, the first feed water preheater 13, and the first steam generator 15 are modified in the storage space 10 in a plane perpendicular to the axis of the storage space 10. It is installed in an extra space excluding the region where the quality furnace 17 is formed.
  • the desulfurizer 12, the CO transformer 22, and the first steam generator 15 are integrated so as to fit in the surplus space in a compact manner.
  • the desulfurizer 12 and the CO converter 22 are configured to include a concentric cylindrical container in which the outer tank portion surrounds the outer periphery of the inner tank portion, and a desulfurization catalyst (for example, ultrahigh-order desulfurization)
  • the desulfurizer 12 is formed by filling the catalyst
  • the CO shifter 22 is formed by filling the inner tank portion with a CO shift catalyst (for example, a copper zinc catalyst).
  • coil piping for heat removal and steam generation is loaded into the CO conversion catalyst in the inner tank portion, and the first water vapor generator 15 is formed in the inner tank portion.
  • the first feed water preheater 13 is a plate-type heat exchanger that preheats pure water supplied from a feed water source by heat exchange with the high-temperature shift gas generated by the CO shift converter 22.
  • the 1st water supply preheater 13 is installed in the clearance gap between the outer tank part in the surplus space, and the reforming furnace 17.
  • the inlet of the desulfurizer 12 provided on one end side of the outer tub portion is connected to the outlet of the raw material compressor 11 via a pipe, and the outlet of the desulfurizer 12 provided on the other end side of the outer tub portion is an inlet.
  • the pipes 36 are connected to the inlet pipes 32 of the respective reforming pipes 18.
  • the CO converter 22 provided at one end of the inner tank is connected to the outlet pipe 33 of each reforming pipe 18 via the outlet pipe 37, and the CO converter provided at the other end of the inner tank.
  • the outlet of the vessel 22 is connected to the gas inlet of the first feed water preheater 13 via a pipe.
  • One end of the coil pipe of the first steam generator 15 on the inlet side is connected to the feed outlet of the first feed water preheater 13 through the pipe.
  • the other end of the coil pipe of the first steam generator 15 on the outlet side is connected to the inlet pipe 36 via a branch pipe, and the steam generated by the first steam generator 15 and the desulfurizer 12 are desulfurized.
  • the raw material gas is mixed. Pure water is supplied from the water supply source to the water supply inlet of the first water supply preheater 13.
  • a gas outlet of the first feed water preheater 13 is connected to a gas inlet of a gas cooler 23 provided outside the accommodation space 10 via a pipe.
  • FIG. 4 shows the waste heat recovery equipment (second feed water preheater 14, second steam generator 16, gas preheater 20, air preheater) provided at the furnace wall, the furnace top, and the furnace bottom of the reforming furnace 17. It is an expanded view which shows the container 21) typically.
  • the heat insulating structure of the reforming furnace 17 covers the outside of the heat insulating structure with a steel plate outer plate in order to prevent the circulation residence heat loss of the combustion gas in the reforming furnace, and further, The outer side is covered with a flex material having high heat insulation performance to increase the heat insulation performance. Then, as shown by the broken line in FIG. 4, a water supply jacket tube of a thin tube coil is welded to the steel plate outer plates provided on the outer surfaces of the furnace wall, the furnace top, and the furnace bottom, and the second water supply preheating is performed. A vessel 14 is formed. With this structure, the temperature in the reforming furnace is 600 ° C.
  • the temperature of the steel plate outer plate is about 200 ° C., and the heat of the combustion gas can be recovered effectively.
  • the water supply jacket pipe is welded to the steel plate outer plate to form the second water supply preheater 14, sufficient heat retention performance can be ensured without increasing the external heat retention by the flex material.
  • the feed water preheated by the first feed water preheater 13 is supplied to the inlet of the bottom feed jacket tube formed at the bottom of the furnace.
  • the outlet of the bottom water supply jacket tube is connected to each inlet of the wall water jacket tube formed in parallel on the left and right of the furnace wall, and the outlets of the wall water jacket tube merge to form the top of the furnace.
  • the preheated water that has exited the outlet of the top water jacket jacket pipe is supplied to the inlet of the second water vapor generator 16 via a pipe.
  • the second steam generator 16 is a waste heat recovery boiler formed by providing a horizontally long opening at the top of the furnace wall and providing a coil pipe in the opening.
  • the outlet of the coil pipe of the second steam generator 16 is connected to the inlet pipe 36 via a branch pipe, and the steam generated by the second steam generator 16 and the steam generated by the first steam generator 15 are The raw material gas desulfurized by the desulfurizer 12 is mixed and mixed.
  • One important point in the operation control of the steam reforming system 1 is to keep the temperature in the CO converter 22 stable at all times.
  • steam in the first steam generator 15 is maintained.
  • the generated amount is controlled, and the amount of steam generated in the first steam generator 15 changes depending on the temperature in the CO converter 22. That is, when only the first steam generator 15 covers the steam supplied to the reforming pipe 18, it is difficult to optimize the temperature in the CO converter 22 and the amount of steam supplied to the reforming pipe 18 at the same time.
  • the feed water preheated by the first feed water preheater 13 is branched in two directions, and one of the feed water is supplied to the first steam generator 15 formed in the CO converter 22.
  • a configuration is adopted in which the other is supplied to the second steam generator 16 for recovering the waste heat of the combustion exhaust gas.
  • the steam generation amount of the first steam generator 15 is controlled, the heat generated in the CO converter 22 is absorbed and the temperature of the CO shift reaction is controlled, and the steam generation amount of the second steam generator 16 is controlled.
  • the generation amount of the process steam supplied to the reforming pipe 18 is controlled, and finally, a stable operation state can be maintained by the combustion control of the burner 19.
  • An exhaust gas flow path for the combustion exhaust gas that has passed through the second steam generator 16 is formed in a space between the pair of left and right wall water supply jacket tubes welded to the steel plate outer plate of the furnace wall, In addition, two sets of a plurality of thin tubes are installed, and a gas preheater 20 and an air preheater 21 are formed.
  • a fuel gas having the same composition as the raw material gas is supplied to the gas preheater 20, and combustion air is taken in from the combustion air header 38 provided with the furnace wall and supplied to the air preheater 21.
  • the fuel gas and the combustion air passing through the two sets of narrow tubes are preheated separately by heat exchange with the combustion exhaust gas, and supplied to a burner 19 provided at the lower end of the furnace wall portion of the reforming furnace 17.
  • the combustion exhaust gas after heat exchange between the gas preheater 20 and the air preheater 21 is discharged to the outside through a chimney 39 provided outside the furnace wall.
  • the heat of the combustion gas and the combustion exhaust gas is obtained. Can be effectively recovered, and heat loss can be effectively reduced. Furthermore, these waste heat recovery devices, reformers (reforming furnace 17, reforming pipe 18), desulfurizer 12, CO converter 22, and first feed water preheater 13 that are integrated with the reforming furnace 17 are configured.
  • the high temperature equipment such as the first steam generator 15 is arranged and formed in the housing space 10 in the reforming furnace 17 or in the vicinity thereof so that the outside air heat radiation area of the high temperature equipment can be obtained. The heat dissipation loss can be greatly reduced.
  • the outer surface of the cylindrical accommodation space 10 is covered with a fireproof cloth in the case of indoor installation, and is covered with an outer cover made of aluminum plate or steel plate in the case of outdoor installation. Airtightness is not necessarily required.
  • the PSA hydrogen separator 25 includes three adsorption tanks 40, a vacuum pump 41, and a supplementary pump 42 as shown in FIG.
  • the inlets of the adsorption tanks 40 are respectively connected to the raw gas pipe 43, the inlets of the vacuum pump 41 and the auxiliary pressure pump 42, and the outlets of the vacuum pump 41 and the auxiliary pressure pump 42 through three on-off valves. Connected separately.
  • the three inlets of the three adsorption tanks 40 are connected to each other through two on-off valves (equalizing valves).
  • the outlets of the vacuum pump 41 and the auxiliary pressure pump 42 are connected to the off-gas pipe 42 via an on-off valve.
  • each adsorption tank 40 is connected to a product hydrogen gas pipe 45 and a pressurized hydrogen gas pipe 46, respectively, via two on-off valves.
  • the three outlets of the three adsorption tanks 40 are connected to each other between the two sets of two outlets via an on-off valve (pressure equalizing valve).
  • the raw gas pipe 43 is connected to the gas outlet of the gas cooler 23 via the drain separator 24, is generated by the CO converter 22, and is removed by the first feed water preheater 13 and the gas cooler 23.
  • the modified gas from which moisture has been removed by the drain separator 24 is supplied to the raw gas pipe 43.
  • the auxiliary pressure pump 42 uses a vacuum pump, but another gas compressor may be used.
  • Each adsorption tank 40 is filled with an adsorbent that adsorbs a gas other than hydrogen, such as CO, CO 2 , and CH 4 , contained in the modified gas supplied to the raw gas pipe 43.
  • a chemical adsorbent that chemically adsorbs CO is used as the adsorbent in addition to a physical adsorbent such as zeolite that physically adsorbs CO 2 , CH 4 , and the like.
  • the chemical adsorbent for example, there is a chemical adsorbent developed by Kobe Steel, etc., in which copper oxide is supported on a porous alumina carrier.
  • the chemical adsorbent has a higher adsorption capacity for CO than the physical adsorbent, so that the amount of off-gas is reduced and the hydrogen recovery rate can be improved. Moreover, the heat loss resulting from offgas is reduced by reducing the amount of offgas.
  • FIG. 5 schematically shows the open / close state of the on-off valve in the first to fourth steps.
  • the white display indicates the open state
  • the black display indicates the closed state.
  • the upper half is outlined white and the lower half is black, indicating that it is open in the third step and closed in the fourth step.
  • the upper half is black and the lower half is white.
  • the closed state is shown in 3 steps, and the open state is shown in the 4th step.
  • the first of the three tanks 40 is subjected to the adsorption process
  • the second layer is subjected to the adsorption process in the previous cycle
  • the third layer is subjected to the adsorption process in the next cycle.
  • the control in the current cycle will be described.
  • an on-off valve between the inlet of the first layer adsorption tank 40 and the raw gas pipe 43, the outlet of the first layer adsorption tank 40, and product hydrogen is opened, the first layer adsorption tank 40 is maintained in a high pressure state and subjected to adsorption treatment, and gas other than hydrogen is adsorbed and removed in the first layer adsorption tank 40 and generated.
  • the produced product hydrogen gas is sent to the product hydrogen gas pipe 45.
  • the opening / closing valve between the inlets of the two adsorption tanks 40 and the opening / closing between the outlets In the first step, as shown in FIG. 5, in order to equalize the tank internal pressure of the second and third adsorption tanks 40, the opening / closing valve between the inlets of the two adsorption tanks 40 and the opening / closing between the outlets. Each valve is opened to allow the second and third adsorption tanks 40 to communicate with each other, the pressure in the third adsorption tank 40 is increased, and the pressure in the second adsorption tank 40 is reduced (equal pressure treatment). .
  • the on-off valve between the inlets of the second layer and the third layer adsorption tank 40 and the on-off valve between the outlets are closed, and the inlet of the second layer adsorption tank 40 and the trapping pressure are closed.
  • An on-off valve between the inlets of the pump 40 and an on-off valve between the inlet of the third layer adsorption tank 40 and the outlet of the pressure pump 40 are opened, and the gap between the second layer and the third layer adsorption tank 40 is opened.
  • the residual gas in the second adsorption tank 40 is compressed by the pressure pump 40 and is sent into the third adsorption tank 40 to be communicated via the pressure pump 40, and the third adsorption tank 40.
  • the inside is further pressurized, and the inside of the second adsorption tank 40 is further depressurized (complementary pressure treatment).
  • the on-off valve between the inlet of the third layer adsorption tank 40 and the outlet of the pressure pump 40 is closed, and the on-off valve between the outlet of the third layer adsorption tank 40 and the pressurized hydrogen gas pipe 46 is closed.
  • Pressurized pressurized hydrogen is fed into the third layer adsorption tank 40 from the pressurized hydrogen gas pipe 46 and pressurized, and vacuum desorption is performed from the second layer adsorption tank 40 by the vacuum pump 41 in preparation for the adsorption process of the next cycle.
  • the off gas (gas other than hydrogen) is sent to the off gas pipe 44 and collected in the fuel gas storage tank.
  • the on-off valve between the outlet of the third layer adsorption tank 40 and the pressurized hydrogen gas pipe 46 is closed to stop the hydrogen pressurization to the third layer adsorption tank 40.
  • the on / off valve between the inlet of the second layer adsorption tank 40 and the inlet of the vacuum pump 41 and the on / off valve between the outlet of the vacuum pump 41 and the off-gas pipe 44 are opened, respectively.
  • the on-off valve between the outlet of the gas and the pressurized hydrogen gas pipe 46 is opened, and the adsorbent is cleaned and the residual gas is purged with respect to the second-layer adsorption tank 40 using a part of the product hydrogen gas.
  • the amount of hydrogen used for desorption and purging in the conventional PSA hydrogen separation can be greatly reduced by performing the purging through the pressure compensation process in the second step and the vacuum desorption process in the third step.
  • the hydrogen recovery rate can be improved.
  • pressure equalization valves (open / close valves) are provided on both the inlet side and the outlet side of each adsorption tank 40. This is for shortening the pressure equalization time and preventing a change in the state in the adsorption tank 40 against an abrupt gas flow, but the pressure equalization valve is provided on one side of the inlet side and the outlet side of each adsorption tank 40. Even if it is provided only in the case, the pressure equalization process can be carried out.
  • the raw material gas is mixed with desulfurized hydrogen gas separated from the product hydrogen gas, compressed to about 0.9 MPa by the raw material compressor 11, and then enters the desulfurizer 12 on the outer periphery of the CO converter 22.
  • adsorptive desulfurization is performed by an ultrahigh-order desulfurization catalyst heated by heat conduction from the CO converter 22.
  • the desulfurized raw material gas is mixed with the water vapor generated by the first water vapor generator 15 in the CO converter 22 and the water vapor generated by the second water vapor generator 16, and is mixed into the reforming pipe 18 in the reforming furnace 17. Steam reforming is performed.
  • the temperature of the raw material gas in the vicinity of the inlet of the outer flow path 30 in the reforming pipe 18 is about 200 to 250 ° C., and the lower end portion of the reforming pipe 18 of the reformed gas steam-reformed through the outer flow path 30. Is about 820 to 870 ° C., and the reformed gas temperature at the outlet of the reforming pipe 18 after passing through the inner flow path 31 is about 400 to 450 ° C. Enter 22.
  • the reformed gas that has entered the CO converter 22 undergoes an exothermic CO conversion reaction, but is cooled by heat exchange with the coil piping of the first steam generator 15 formed in the conversion catalyst. The temperature becomes about 200 ° C., and the transformed gas is fully transformed.
  • the gas to be treated during the CO shift reaction is removed by heating the desulfurization catalyst in the outer tank portion through the outer wall of the CO shift converter 22.
  • the modified gas exiting the CO converter 22 enters the first feed water preheater 13 and is highly recovered.
  • the heat-recovered metamorphic gas enters the gas cooler 23, and the drain is separated and removed by the subsequent drain separator 24, and then enters the PSA hydrogen separator 25 and separated into product hydrogen gas and off-gas.
  • This off-gas is mixed with the fuel gas of 13A city gas, which is the same as the raw material gas, to become the fuel for the burner 19, burned by the combustion air, and heats the reforming pipe 18 in the reforming furnace 17.
  • the combustion exhaust gas generates steam by the second steam generator 16 due to its waste heat, and further exchanges heat between the combustion air and the fuel gas, and is discharged from the chimney at about 100 ° C.
  • Case # 5 used a conventional zeolite instead of a chemical adsorbent as the CO adsorbent, unlike the other cases and the above embodiment.
  • the hydrogen recovery rate of Case # 5 is as low as 82.97%, but the hydrogen gasification efficiency is 90.69%, which is 90% or more. However, the hydrogen gas production volume is reduced to about 91% compared to Case # 4.
  • FIG. 8 is a table comparing the predicted operation results for each condition of the steam reforming system according to the present invention and the predicted operation results of the existing steam reforming system
  • FIG. It is a bar graph which shows the composition ratio of the heat dissipation loss, P fluid cooling loss, combustion exhaust gas loss, and hydrogen gasification efficiency in the prediction operation result according to the conditions to show.
  • Case # 19 refers to the specifications of an existing hydrogen production apparatus with a hydrogen production capacity of 100 m 3 N / h.
  • Cases # 11 to # 13 generally achieve a hydrogen gasification efficiency of 90%, as in cases # 1 to # 4 shown in FIG.
  • the S / C is 2.4, which is larger than 0.7-2.2 of S / C in cases # 1 to # 4, so the hydrogen gasification efficiency is 89.53%, which is only 90%. Is rounded down to the nearest 90%. Therefore, it is preferable that S / C can be set to 1.7 or more and 2.4 or less, and preferably 1.8 or more and 2.3 or less.
  • the heat loss is reduced so that the ratio of the total heat dissipation loss to the heat generation is 6%, and the S / C is 1.7 or more and 2.4 or less, preferably 1.8 or more and 2.3 or less. It turns out that 90% of hydrogen gasification efficiency can be achieved by setting.
  • the PSA hydrogen separator 25 is used to remove hydrogen other than hydrogen and separate hydrogen from the shift gas generated by the CO converter 22.
  • a CO selective oxidation remover that selectively removes CO may be provided, and CO 2 may be separated and removed by a membrane separation method or the like.
  • the scale of the PSA hydrogen separation device 25 can be reduced by providing a CO selective oxidation remover, a CO 2 membrane separation device, or the like before the PSA hydrogen separation device 25.
  • the PSA hydrogen separation device 25 uses a three-tank PSA hydrogen separation device to perform the pressure compensation process, but instead of the pressure compensation process, for example, four layers
  • the pressure equalizing process may be performed twice using a PSA hydrogen separator of the type.
  • the PSA hydrogen separation device 25 is not limited to the three-tank type or the four-tank type, and the operation control method is not limited to the control method of the above embodiment.
  • the first steam generator 15 and the second steam generator 16 are provided in parallel. For example, adjusting the amount of heat exchange between the CO converter 22 and the desulfurizer 12; Alternatively, in the case where the amount of water vapor generated by the first water vapor generator 15 can be optimized together with the temperature control of the CO shift reaction by supplying the first water vapor generator 15 with the feed water that has passed through the second water feed preheater 14. However, the second water vapor generator 16 is not necessarily provided.
  • the second feed water preheater 14 in order to recover the waste heat of the combustion exhaust gas discharged from the reforming furnace 17, the second feed water preheater 14, the first steam generator 15, the gas preheater 20, and the air preheater 21 are collected.
  • the specific configuration example of the waste heat recovery apparatus is not limited to the configuration illustrated in FIG. 4.
  • the feed water that has passed through the first feed water preheater 13 is supplied to the second feed water preheater 14.
  • the feed water that has passed through the first feed water preheater 13 is supplied to the first steam generator 15.
  • the second feed water preheater 14 may be configured to supply feed water having the same temperature as that supplied to the first feed water preheater 13.
  • the top view shape (outer shape) of the reforming furnace 17 is a shape in which a part of a circular outer peripheral portion as shown in FIG.
  • the top view shape of the space is substantially “C” shape, but the outer shape of the reforming furnace 17 and the top view shape of the internal space are not limited to those illustrated in FIG. 2.
  • the top view shape (outer shape) of the reforming furnace 17 may be a complete donut shape, and the inner space of the reforming furnace 17 may be formed in an annular shape.
  • the desulfurizer 12, the CO converter 22, and A surplus space for housing the first steam generator 15 and the like may be provided in the center of the housing space 10 and the entire circumference thereof may be surrounded by the reforming furnace 17.
  • the number of the reforming pipes 18 is not limited to the five illustrated in FIG. 1 and can be appropriately changed according to the shape and size of the internal space of the reforming furnace 17.
  • the top view shape of the accommodation space 10 is not limited to a circle, and may be, for example, an ellipse or a rectangle with rounded corners.
  • the outer shape of the reforming furnace 17 as viewed from above may be changed in accordance with the shape of the accommodation space 10 as viewed from above.
  • the shape and dimensions of the reforming tube 17 are not limited to the contents described in the above embodiment as long as the reforming tube 17 has a double tube structure.
  • either the outer pipe 26 or the inner pipe 27 or either one of them may be a straight pipe whose diameter is not expanded at the center portion.
  • the outer pipe 26 and the inner pipe 27 Even if both are straight pipes, the heat transfer amount (heat flux) per unit heat transfer area conducted in the outer flow path 30 decreases toward the upper side, and the temperature of the gas to be processed increases at the upper end portion of the outer flow path 30. The effect of becoming moderate can be achieved.
  • the blocking structure and shape of the end portions of the outer tube 26 and the inner tube 27 of the reforming tube 17 are not limited to the contents described in the above embodiment.
  • the inlet pipe 32 and the outlet pipe 33 are provided on the upper side of the reforming pipe 18.
  • the upper and lower sides of the reforming pipe 18 are inverted to reform the inlet pipe 32 and the outlet pipe 33.
  • a gas mixture of raw material gas and water vapor that has entered from the reforming pipe 18 may be disposed below the pipe 18 so as to pass upward through the external flow path 30.
  • the burner 19 is installed not on the lower end of the furnace wall or the bottom of the furnace in the reforming furnace 17 but on the upper end of the furnace wall or the top of the furnace in the reforming furnace 17.
  • the desulfurizer 12 and the CO converter 22 are formed in the outer tank portion of the concentric cylindrical container and the CO converter 22 is formed in the inner tank portion.
  • the desulfurizer 12 may be formed in the inner tank portion, and the CO transformer 22 may be formed in the outer tank portion.
  • the desulfurizer 12 is not necessarily provided. However, regardless of the presence or absence of the desulfurizer 12, a small amount of hydrogen is added to the source gas, It is preferable to suppress the occurrence.
  • This power generation system includes a steam reforming system 1 according to this embodiment and a power generation device that consumes hydrogen generated by the hydrogen production system 1 to generate power, and the hydrogen gasification efficiency of the steam reforming system 1 is high. A case of 90% or more is assumed.
  • the power generation efficiency of the power generation device is 50% and the hydrogen gasification efficiency of the hydrogen production system is 90%, considering the orthogonal transformation efficiency and private power consumption, the power transmission end efficiency (HHV) is about 44%.
  • the power generation efficiency is comparable to natural gas gas turbine combined cycle (GTCC) power generation.
  • this power generation system can also be suitably used for a hydrogen supply base (satellite hydrogen supply base) for vehicles that use hydrogen as fuel, such as fuel cell vehicles (FCV).
  • a hydrogen supply base for vehicles that use hydrogen as fuel
  • FCV fuel cell vehicles
  • the power generation device constitutes a power supply facility for supplying electric power to an electric vehicle provided in the hydrogen supply base
  • a high operating rate can be obtained by supplying the electric power generated by the power generation device toward the electric vehicle.
  • the generated power can be used for compressed hydrogen power and can be sold externally.
  • the present invention relates to a steam reforming system for producing hydrogen used for fuel cells and metal processing by reforming a hydrocarbon-based gas, and a power generation system including the steam reforming system. And is particularly useful for a satellite hydrogen supply base for a fuel cell vehicle (FCV).
  • FCV fuel cell vehicle

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Abstract

Provided is a steam reforming system that can effectively suppress heat loss and can achieve a hydrogen gasification efficiency of 80% or more or preferably 90% or more. The invention is provided with a reformer, in which a plurality of reforming tubes 18 are disposed so as to be connected in parallel in a reforming furnace 17, steam generators 15, 16, which generate steam for a reforming reaction, a CO converter 22, and a combustor 19, which supplies heat into the reforming furnace 17, wherein: the reforming tubes 18 are configured to comprise an outer tube 26, of which both ends are closed, and an inner tube 27, which is accommodated in the outer tube 26 and of which one end is closed and the other end is open, said tubes being coaxial, wherein an inlet is provided at one end side of the outer tube 26, an outlet is provided at one end side of the inner tube 27, an outer channel 30 formed between the outer tube 26 and the inner tube 27 and an inner channel 31 formed inside the inner tube 27 communicate at the other end side of the outer tube 26, and a reforming catalyst is filled into at least the outer channel 30; and the combustor 19 is provided at the other end side in the reforming furnace 17.

Description

水蒸気改質システム及び発電システムSteam reforming system and power generation system
　本発明は、燃料電池や金属処理の用に供される水素を、炭化水素系ガスを改質することで製造する水蒸気改質システム、及び、当該水蒸気改質システムを備えて構成される発電システムに関する。 The present invention relates to a steam reforming system for producing hydrogen used for fuel cells and metal processing by reforming a hydrocarbon-based gas, and a power generation system including the steam reforming system. About.
　最近、わが国では燃料電池自動車（ＦＣＶ）が出現し、それに対応するための高効率のサテライト水素供給設備が望まれている。しかし、斯かる高効率水素供給設備の当面の目標である水素ガス化効率８０％には未だ到達していないのが現状である。 Recently, fuel cell vehicles (FCVs) have emerged in Japan, and high-efficiency satellite hydrogen supply equipment is required to cope with them. However, at present, the hydrogen gasification efficiency of 80%, which is the immediate target of such a high-efficiency hydrogen supply facility, has not yet been reached.
　図１０に、サテライト水素供給設備を構成する従来の水素製造システム１００の一構成例を模式的に示す。図１０では、水素製造システム１００を構成する主要な機器と当該機器間の物質の流れを示している。 FIG. 10 schematically shows a configuration example of a conventional hydrogen production system 100 constituting a satellite hydrogen supply facility. FIG. 10 shows the main equipment constituting the hydrogen production system 100 and the material flow between the equipment.
　図１０に示される従来の水素製造システム１００は、原料圧縮機１０１、脱硫器１０２、給水予熱器１０３、廃熱回収ボイラ１０４、改質炉１０５、改質管１０６、原料予熱器１０７、過熱器１０８、バーナ１０９、空気予熱器１１０、ＣＯ変成器１１１、ガス冷却器１１２、ＰＳＡ水素分離装置１１３等を備えて構成される。 A conventional hydrogen production system 100 shown in FIG. 10 includes a raw material compressor 101, a desulfurizer 102, a feed water preheater 103, a waste heat recovery boiler 104, a reforming furnace 105, a reforming pipe 106, a raw material preheater 107, and a superheater. 108, a burner 109, an air preheater 110, a CO converter 111, a gas cooler 112, a PSA hydrogen separator 113, and the like.
　図１０に示される構成例では、メタンを主成分とする都市ガス（１３Ａガス）等の原料ガスは、原料圧縮機１０１で圧縮され、改質炉１０５内に設けられた原料予熱器１０７で予熱された後、該都市ガスに含まれる硫黄化合物が脱硫器１０２で除去され、改質管１０６に供給される。給水予熱器１０３で、ＣＯ変成器１１１で生成された高温の変性ガスと熱交換して予熱された水は、ＣＯ変成器１１１のＣＯ変性反応で生じた熱との熱交換により蒸発し、改質炉１０５内の過熱器１０８で過熱され、脱硫処理された原料ガスと合流して、改質管１０６に供給される。原料ガスの一部は燃料ガスとしてバーナ１０９に供給され、燃焼用空気は、空気予熱器１１０で改質炉１０５から排出された燃焼排ガスの廃熱との熱交換により予熱され、バーナ１０９に供給される。改質管１０６に供給された原料ガスと水蒸気は、バーナ１０９による加熱により改質反応を起こし、水素と一酸化炭素を含む改質ガスが生成される。ＣＯ変成器１１１において、改質ガス中に含まれる一酸化炭素が二酸化炭素に転化され、ＣＯ濃度の低下した変性ガスが生成される。変性ガスは、給水予熱器１０３とガス冷却器１１２で降温された後、ＰＳＡ水素分離装置１１３において、水素以外のガスを吸着除去され、含有水素濃度の上昇した製品水素が生成される。ＰＳＡ水素分離装置１１３で回収された水素以外のガス（オフガス）は、燃焼ガスとしてバーナ１０９に供給される。 In the configuration example shown in FIG. 10, a raw material gas such as city gas (13A gas) mainly composed of methane is compressed by the raw material compressor 101 and preheated by the raw material preheater 107 provided in the reforming furnace 105. After that, the sulfur compound contained in the city gas is removed by the desulfurizer 102 and supplied to the reforming pipe 106. In the feed water preheater 103, the water preheated by exchanging heat with the high-temperature modified gas generated in the CO converter 111 is evaporated by heat exchange with the heat generated in the CO modification reaction of the CO converter 111, The material gas is superheated in the superheater 108 in the quality furnace 105 and merged with the desulfurized raw material gas and supplied to the reforming pipe 106. Part of the raw material gas is supplied as fuel gas to the burner 109, and the combustion air is preheated by heat exchange with the waste heat of the combustion exhaust gas discharged from the reforming furnace 105 by the air preheater 110 and supplied to the burner 109. Is done. The raw material gas and water vapor supplied to the reforming tube 106 undergo a reforming reaction by heating by the burner 109, and a reformed gas containing hydrogen and carbon monoxide is generated. In the CO converter 111, carbon monoxide contained in the reformed gas is converted into carbon dioxide, and a modified gas having a reduced CO concentration is generated. After the denatured gas is cooled by the feed water preheater 103 and the gas cooler 112, the PSA hydrogen separator 113 adsorbs and removes gas other than hydrogen to produce product hydrogen having an increased concentration of hydrogen. Gas other than hydrogen (off-gas) recovered by the PSA hydrogen separator 113 is supplied to the burner 109 as combustion gas.
　従来の水素製造のプロセス設計では、例えば、図１０に示されるような物質の流れに従って、物質収支及び熱収支を計算し、その過程で発生する熱損失は、過去の経験を参考にして値を決定することが多かった。一例として、図１０に示される物質の流れに対して、図１１に示されるようなエネルギ収支図がよく用いられている。水素ガス化効率の向上は、熱損失の減少を意味することから、熱損失の本質の検討が重要であるが、図１１に示される熱損失部分から、その状態を詳しく把握することは困難である。 In the conventional hydrogen production process design, for example, the material balance and heat balance are calculated according to the material flow as shown in FIG. 10, and the heat loss generated in the process is determined with reference to past experience. There were many decisions. As an example, an energy balance diagram as shown in FIG. 11 is often used for the material flow shown in FIG. Since improvement of hydrogen gasification efficiency means a reduction in heat loss, it is important to study the essence of heat loss, but it is difficult to grasp the state in detail from the heat loss portion shown in FIG. is there.
　一方、本出願人は、過去に、下記の特許文献１に示すように、水素製造システムを構成する改質器とバーナを上段に配し、ＣＯ変成器と脱硫器等を下段に配した上下構造とし、各部を同軸状に構成することで、各部間を連絡する配管を不要とした熱効率の高い水素製造装置を開発している。しかし、当該水素製造装置においても、水素ガス化効率は８０％には至っていない。 On the other hand, in the past, as shown in the following Patent Document 1, the present applicant has arranged a reformer and a burner constituting the hydrogen production system in the upper stage, and a CO converter and a desulfurizer are arranged in the lower stage. By developing the structure and configuring each part coaxially, we have developed a highly thermal-efficiency hydrogen production system that eliminates the need for piping connecting the parts. However, even in the hydrogen production apparatus, the hydrogen gasification efficiency does not reach 80%.
特開２０１０－１００４９４号公報JP 2010-1000049 A
　上述のように、従来の水素製造システムでは、８０％以上の水素ガス化効率が達成されておらず、また、従来の水素製造のプロセス設計においても、熱損失の本質の検討が不十分であり、水素ガス化効率の向上のための熱損失の減少は十分に図られていなかった。 As described above, in the conventional hydrogen production system, hydrogen gasification efficiency of 80% or more has not been achieved, and in the process design of conventional hydrogen production, examination of the essence of heat loss is insufficient. However, heat loss for improving hydrogen gasification efficiency has not been sufficiently reduced.
　本発明は、上述の問題点に鑑みてなされたものであり、その目的は、熱損失を効果的に抑制でき、８０％以上好ましくは９０％以上の水素ガス化効率を達成し得る水蒸気改質システムを提供することにある。 The present invention has been made in view of the above-mentioned problems, and its purpose is to perform steam reforming capable of effectively suppressing heat loss and achieving hydrogen gasification efficiency of 80% or more, preferably 90% or more. To provide a system.
　図１２は、水素製造に関するシステムバウンダリを設定し、物質の入出力の状況を示したものである。図１２において、入力となる物質は、原料ガス、プロセス蒸気となるプロセス水、及び、燃料と燃焼用空気であり、出力となる物質は、製品水素、プロセス蒸気の内の反応しなかった未分解蒸気、及び、燃焼排ガスである。更に、水素製造システムは全体から見ると発熱系であって放散熱を伴っている。図１２において、プロセス水の変化を見ると、大部分は製品水素ガスとなり、残りの水素ガスはＰＳＡ分離においてオフガスとなり燃焼されて排ガス中の水蒸気となる。エネルギ収支から見ると、未分解蒸気の内、熱回収されて凝縮水になった部分を除き、出力の水分の殆どは水蒸気となって排出され、その後、冷却・凝縮される。従って、この水蒸気が少ないほど熱損失は小さくなる。それ以外に、燃焼プロセスにおける余剰空気による損失もあるが、主たる熱損失の原因は未分解蒸気と放散熱となっている。 Fig. 12 shows the system boundary for hydrogen production and shows the input / output status of substances. In FIG. 12, the materials to be input are raw material gas, process water to be process steam, and fuel and combustion air, and the materials to be output are undecomposed of product hydrogen and process steam that have not reacted. Steam and combustion exhaust gas. Furthermore, the hydrogen production system as a whole is an exothermic system and involves dissipated heat. In FIG. 12, when looking at the change in process water, most of it becomes product hydrogen gas, and the remaining hydrogen gas becomes off-gas in PSA separation and burns to become water vapor in the exhaust gas. From the viewpoint of energy balance, most of the output water is discharged as water vapor except for the portion of the undecomposed steam that has been recovered by heat to become condensed water, and then cooled and condensed. Therefore, the heat loss decreases as the water vapor decreases. In addition, there are losses due to excess air in the combustion process, but the main causes of heat loss are undecomposed steam and heat dissipated.
　例えば、図１１に示されるエネルギ収支図に対して、当該エネルギ収支図と同じデータから、例えば図１３に例示するように、夫々の流体の温度・エンタルピ線図を、熱損失分析図として描き、熱損失の分布を定量的に把握し、流体間の温度差やピンチポイントを確認することで、運転確認やシステムの最適設計が可能となる。 For example, with respect to the energy balance diagram shown in FIG. 11, from the same data as the energy balance diagram, as illustrated in FIG. 13, for example, the temperature / enthalpy diagram of each fluid is drawn as a heat loss analysis diagram, By quantitatively grasping the distribution of heat loss and checking the temperature difference and pinch point between fluids, it is possible to check the operation and optimize the system design.
　図１３に例示した熱損失分析図において、熱損失の大きい部分は、燃焼排ガス損失、燃焼ガス側の放熱損失、プロセス流体の排熱損失である。 In the heat loss analysis diagram illustrated in FIG. 13, the portions with large heat loss are the combustion exhaust gas loss, the heat radiation loss on the combustion gas side, and the exhaust heat loss of the process fluid.
　燃焼排ガス損失は、プロセスの加熱以外に、全体の放熱を担うための燃焼量の増加や、燃料となるオフガス中の水素分が燃焼して水蒸気分が多く含むこと、オフガス中にＣＯ２が多く含まれること等が要因となっている。そのため、ＰＳＡ分離における水素回収率が高くなると当該熱損失は少し減少するが、その割合は通常のボイラ等の排ガス損失に比べて大きい値になっている。 Combustion exhaust gas loss is not only due to process heating, but also increases the amount of combustion to bear the overall heat dissipation, the hydrogen content in the off-gas used as fuel burns and contains a large amount of water vapor, and the CO 2 in the off-gas is large. Inclusion is a factor. Therefore, when the hydrogen recovery rate in the PSA separation increases, the heat loss slightly decreases, but the ratio is larger than the exhaust gas loss of a normal boiler or the like.
　燃焼ガス側の放熱は、プロセス設計において、同じ加熱源から生じる改質ガス側の放熱と一緒に考慮されるのが普通である。図１３に例示した熱損失分析図においては、プラントの全放熱量の燃焼する燃料の発熱量（ＨＨＶ）に対する比率は２６．１％となっている。この値はパッケージボイラや大型ボイラの２～５％に比べ大きい値であるが、大型の水素製造プラントの場合でも１５～２０％となる。その理由は高温の改質炉の炉体が大きく、高温部の機器・配管の構造に由来しているためであり、改善の余地が大きい。 The heat release on the combustion gas side is normally considered in the process design together with the heat release on the reformed gas side generated from the same heating source. In the heat loss analysis diagram illustrated in FIG. 13, the ratio of the total heat release amount of the plant to the calorific value (HHV) of the burning fuel is 26.1%. This value is larger than 2 to 5% for package boilers and large boilers, but is 15 to 20% even for large hydrogen production plants. The reason is that the furnace body of the high-temperature reforming furnace is large and is derived from the structure of the equipment and piping in the high-temperature part, so there is much room for improvement.
　プロセス流体の排熱損失の大部分は、未分解蒸気の潜熱によるものである。当該未分解蒸気の潜熱による損失は、原料ガス中の炭素とプロセス蒸気（水蒸気）のモル比Ｓ／Ｃ（水蒸気／炭素）と、水蒸気改質反応における圧力や温度に影響する。通常、プロセス流体中の未分解蒸気の一部の熱はボイラ給水の予熱により回収されるが、上記Ｓ／Ｃが大きい場合は、プロセス流体と給水側の温度差にピンチポイントが出現して熱回収量が制限され、未分解蒸気が多くなる。 大 Most of the waste heat loss of the process fluid is due to the latent heat of undecomposed steam. The loss due to the latent heat of the undecomposed steam affects the molar ratio S / C (steam / carbon) of carbon and process steam (steam) in the raw material gas, and the pressure and temperature in the steam reforming reaction. Usually, a part of the heat of undecomposed steam in the process fluid is recovered by preheating the boiler feed water. However, if the S / C is large, a pinch point appears in the temperature difference between the process fluid and the feed water side, and the heat is lost. The amount of recovery is limited and the amount of undecomposed steam increases.
　以上より、水素ガス化効率の向上のための熱損失低減には、１）燃焼排ガス損失の低減、２）放熱損失の低減、３）未分解蒸気の低減、４）ＰＳＡ分離における水素回収率の向上、等の対策が有効である。 From the above, heat loss reduction for improving hydrogen gasification efficiency includes 1) reduction of combustion exhaust gas loss, 2) reduction of heat dissipation loss, 3) reduction of undecomposed steam, and 4) hydrogen recovery rate in PSA separation. Measures such as improvement are effective.
　上記１）～４）の対策は、機器及びシステム設計の工夫による対策と、運転条件の見直しによる対策がある。尚、後述するように、運転条件の見直しに伴う副作用に対処するための機器側の対策が必要となる場合がある。 Measures 1) to 4) above include measures by devising equipment and system design and measures by reviewing operating conditions. As will be described later, it may be necessary to take measures on the device side to deal with side effects associated with the review of operating conditions.
　燃焼排ガス損失の低減には、上記４）のＰＳＡ分離における水素回収率の向上の他、燃焼空気比の低減、及び、排ガス温度の低下が、基本的な対策として考えられる。主として、前者は運転条件の見直しにより行い、後者は、廃熱回収の高効率化等の機器及びシステム設計の工夫により実施する。 In order to reduce the combustion exhaust gas loss, in addition to the improvement of the hydrogen recovery rate in the PSA separation described in 4) above, the reduction of the combustion air ratio and the reduction of the exhaust gas temperature are considered as basic measures. The former is performed mainly by reviewing operating conditions, and the latter is performed by devising equipment and system design such as increasing the efficiency of waste heat recovery.
　放熱損失の低減は、熱交換機能の向上、高断熱化、廃熱回収の高効率化、等の機器及びシステム設計の工夫により実施する。 放熱 Reduction of heat dissipation loss will be implemented through device and system design improvements such as improved heat exchange function, higher heat insulation, and higher efficiency of waste heat recovery.
　未分解蒸気の低減は、基本的に、改質温度を許容範囲内で高く設定し、原料ガスとプロセス蒸気の供給を低Ｓ／Ｃで行う等の運転条件の見直しにより行う。しかし、低Ｓ／Ｃ運転では、水蒸気改質反応における炭化水素の熱分解によるカーボン発生が顕著となり、更に、ＣＯ変成器から出力される変成ガス中のＣＯ濃度の増加も問題となる。よって、未分解蒸気の低減には、低Ｓ／Ｃに起因する上記問題を、機器及びシステム側において別途対処する必要がある。 低 減 Reduction of undecomposed steam is basically done by reviewing the operating conditions such as setting the reforming temperature high within the allowable range and supplying the raw material gas and process steam at low S / C. However, in low S / C operation, carbon generation due to thermal decomposition of hydrocarbons in the steam reforming reaction becomes significant, and an increase in the CO concentration in the shift gas output from the CO shift converter becomes a problem. Therefore, in order to reduce the undecomposed steam, it is necessary to separately deal with the above-mentioned problem due to low S / C on the device and system side.
　ＰＳＡ分離における水素回収率の向上は、高性能吸着剤の使用、吸着槽の圧力制御の改良による高回収率化、等の機器及びシステム設計の工夫により実施する。例えば、高性能吸着剤として、ＣＯに対する吸着能力の高い化学吸着剤を使用することで、水素回収率の向上とともに、低Ｓ／Ｃに起因するＣＯ濃度増加にも対処できる。 ∙ Improvement of hydrogen recovery rate in PSA separation will be implemented by equipment and system design such as high performance adsorbent and high recovery rate by improving pressure control of adsorption tank. For example, by using a chemical adsorbent having a high adsorption capability for CO as a high-performance adsorbent, it is possible to cope with an increase in CO concentration caused by low S / C as well as an improvement in the hydrogen recovery rate.
　低Ｓ／Ｃに起因するカーボン発生の対策として、改質器の前段に脱硫器を設ける、原料ガス中に適量の水素を加える、炭化水素を低温で改質するプレリフォーマを設置する等が考えられる。但し、これらの機器及びシステム設計の工夫による対策を、上述の他の対策を阻害しないように、できれば上述の他の対策に資するように実施できることが望ましい。 Possible countermeasures against carbon generation due to low S / C include installing a desulfurizer in front of the reformer, adding an appropriate amount of hydrogen to the raw material gas, and installing a pre-reformer that reforms hydrocarbons at low temperatures. It is done. However, it is desirable that countermeasures based on these device and system design ideas can be implemented so as to contribute to the other countermeasures described above, if possible, so as not to hinder the other countermeasures described above.
　本願発明者は、熱損失の内容を定量的に把握し、且つ、詳細に検討した結果、８０％以上好ましくは９０％以上の水素ガス化効率を達成し得る水蒸気改質システムを実現するために、機器及びシステム設計の工夫により、以下に示す本発明に至った。 In order to realize a steam reforming system capable of achieving a hydrogen gasification efficiency of 80% or more, preferably 90% or more as a result of quantitatively grasping the contents of heat loss and examining in detail, the inventor of the present application. By the device and system design, the present invention shown below has been reached.
　本発明に係る水蒸気改質システムは、炭化水素を含む原料ガスを水蒸気と反応させて、水素と一酸化炭素を少なくとも含む改質ガスを生成する複数の改質管を、断熱構造体で囲まれた筒状の改質炉内に夫々の軸方向を互いに平行にして並列に連結配置してなる改質器と、前記改質器に供給する水蒸気を発生する蒸気発生器と、前記改質ガスに含まれる一酸化炭素の少なくとも一部を水蒸気と反応させて二酸化炭素に変成させ、前記改質ガスより含有一酸化炭素濃度の低下した変成ガスを生成する変成器と、燃料ガスを燃焼して前記改質炉内に熱供給を行う燃焼器とを、備えてなり、
　前記改質管の夫々が、両端が閉じられた外管と、前記外管内に収容され一端が閉じ他端が開口した内管を同軸状に備え、且つ、前記外管の一端側に入口を備え、前記内管の一端側に出口を備え、且つ、前記外管と前記内管の間に形成された外側流路と前記内管内に形成された内側流路が、前記外管内の他端側において連通しており、且つ、少なくとも前記外側流路に改質触媒が充填されて構成され、
　前記燃焼器が、前記改質炉内または前記改質炉の炉壁部の前記外管の他端側に設けられ、前記改質器と筒状の前記変成器が、互いに隣接して、前記複数の改質管と筒状の前記変成器の夫々の軸方向を互いに平行にして、筒状の１つの収容空間内に設置されていることを第１の特徴とする。 In a steam reforming system according to the present invention, a plurality of reforming pipes that generate a reformed gas containing at least hydrogen and carbon monoxide by reacting a raw material gas containing hydrocarbons with steam are surrounded by a heat insulating structure. A reformer formed by connecting and connecting in parallel with each other in a cylindrical reforming furnace, a steam generator for generating steam to be supplied to the reformer, and the reformed gas The carbon monoxide contained in the gas is reacted with water vapor to be converted into carbon dioxide, and a reformer for generating a transformed gas having a reduced concentration of carbon monoxide from the reformed gas, and burning a fuel gas A combustor for supplying heat into the reforming furnace,
Each of the reforming pipes is coaxially provided with an outer pipe whose both ends are closed, and an inner pipe which is accommodated in the outer pipe and whose one end is closed and the other end is opened, and an inlet is provided on one end side of the outer pipe. An outlet is provided on one end side of the inner tube, and an outer channel formed between the outer tube and the inner tube and an inner channel formed in the inner tube are connected to the other end in the outer tube. And at least the outer flow path is filled with a reforming catalyst,
The combustor is provided in the reforming furnace or on the other end side of the outer tube of the furnace wall of the reforming furnace, the reformer and the tubular transformer are adjacent to each other, and The first feature is that the plurality of reforming tubes and the cylindrical transformer are installed in one cylindrical accommodation space with the axial directions thereof being parallel to each other.
　上記第１の特徴を有する水蒸気改質システムによれば、外側流路における吸熱反応である水蒸気改質反応に対して、外管の外側の燃料の燃焼熱と内管の内側を通過する高温の改質ガスから効率的に加熱されるため、改質温度を許容範囲内で容易に高くでき、更に、熱交換に供される管壁の面積を大きくできるため、熱交換効率を高くできる。これにより、放熱損失の低減、及び、未分解蒸気の低減が図れる。 According to the steam reforming system having the first feature described above, the heat of combustion of the fuel outside the outer pipe and the high temperature passing through the inside of the inner pipe against the steam reforming reaction that is an endothermic reaction in the outer flow path. Since it is efficiently heated from the reformed gas, the reforming temperature can be easily increased within an allowable range, and furthermore, the area of the tube wall used for heat exchange can be increased, so that the heat exchange efficiency can be increased. Thereby, reduction of heat dissipation loss and reduction of undecomposed steam can be achieved.
　更に、燃焼器が改質炉内または改質炉の炉壁部の外管の他端側に設けられているため、燃焼器が生成した高温の燃焼ガスは、外管の外壁面と改質炉の内壁面の間の燃焼ガス流路を、当該流路の外管の他端側から一方端側に向けて通流する。ここで、燃焼ガスの熱が外管の管壁に吸収され、燃焼ガス温度は、外管の他端側から一方端側に向けて低下する。例えば、一例として、燃焼ガス流路の他端側が約１０００℃で、一方端側で約５００℃まで低下する場合があり得る。改質炉内の伝熱は放射伝熱が主であり、当該放射伝熱は絶対温度の４乗の差で行われるというステファン・ボルツマンの法則に従うため、外管の他端側では温度が高く、単位伝熱面積当たりの伝熱量（熱流束）が多くなり、外管の一端側では温度が低く、単位伝熱面積当たりの伝熱量（熱流束）が少なくなる。従って、外側流路内の一端側（入口側）寄りの一部領域は、被処理ガスの温度上昇が緩やかなものになり、プレリフォーマとして機能し、低Ｓ／Ｃ運転に起因するカーボン析出を抑制できる。 Furthermore, since the combustor is provided in the reforming furnace or on the other end side of the outer pipe of the furnace wall of the reforming furnace, the high-temperature combustion gas generated by the combustor and the outer wall surface of the outer pipe are reformed. The combustion gas flow path between the inner wall surfaces of the furnace flows from the other end side of the outer pipe of the flow path toward the one end side. Here, the heat of the combustion gas is absorbed by the tube wall of the outer tube, and the combustion gas temperature decreases from the other end side of the outer tube toward the one end side. For example, as an example, there may be a case where the other end side of the combustion gas passage is about 1000 ° C. and the other end side is lowered to about 500 ° C. The heat transfer in the reforming furnace is mainly radiant heat transfer, and the radiant heat transfer follows the Stefan-Boltzmann law that the difference is the fourth power of the absolute temperature. The amount of heat transfer per unit heat transfer area (heat flux) increases, the temperature is low at one end of the outer tube, and the amount of heat transfer per unit heat transfer area (heat flux) decreases. Therefore, a partial region near one end side (inlet side) in the outer channel becomes a moderate temperature rise of the gas to be processed, functions as a pre-reformer, and causes carbon precipitation due to low S / C operation. Can be suppressed.
　また、内側流路を通流する改質ガス温度も、燃焼ガスと同様、改質ガスの熱が内管の管壁に吸収され、内管の他端側から一方端側に向けて低下する。例えば、一例として、燃焼ガス流路の他端側が約８６０℃で、一方端側で約４５０℃まで低下する場合があり得る。
よって、内側流路を通流する改質ガス温度の変化も、燃焼ガス温度の変化と同様に、外側流路内の一端側（入口側）寄りの一部領域は、被処理ガスの温度上昇が緩やかなものになり、プレリフォーマとして機能し、低Ｓ／Ｃ運転に起因するカーボン析出の抑制に寄与する。また、改質管出口の改質ガス温度が下がるため、配管フランジの接続が容易になるという利点もある。 Further, the temperature of the reformed gas flowing through the inner flow path is also reduced by the heat of the reformed gas being absorbed by the tube wall of the inner tube from the other end side of the inner tube toward the one end side, like the combustion gas. . For example, as an example, there may be a case where the other end side of the combustion gas passage is about 860 ° C. and the other end side is lowered to about 450 ° C.
Therefore, the change in the temperature of the reformed gas flowing through the inner flow path is similar to the change in the combustion gas temperature. Becomes gentle, functions as a pre-reformer, and contributes to the suppression of carbon deposition due to low S / C operation. Further, since the reformed gas temperature at the reforming pipe outlet is lowered, there is an advantage that the connection of the piping flange becomes easy.
　更に、改質器と変成器を、両者間を連絡する配管も含め、上記収容空間内に一体化して収容できるため、高温機器の外気放熱面積を小さくでき、放熱損失の低減が図れる。 Furthermore, since the reformer and the transformer can be integrated and accommodated in the accommodation space including the piping connecting the two, the outside heat radiation area of the high temperature equipment can be reduced, and the heat radiation loss can be reduced.
　本発明に係る水蒸気改質システムは、上記第１の特徴に加え、前記改質管の軸心に垂直な平面における前記外管及び前記外側流路の各断面積が、軸心方向の中央部分より前記外管及び前記内管の前記一端側の方が当該中央部分の前記他端側の方より大きいことを第２の特徴とする。 In the steam reforming system according to the present invention, in addition to the first feature, each cross-sectional area of the outer pipe and the outer flow path in a plane perpendicular to the axis of the reforming pipe is a central portion in the axial direction. The second feature is that the one end side of the outer tube and the inner tube is larger than the other end side of the central portion.
　上記第２の特徴を有する水蒸気改質システムによれば、前記外側流路の入口側のプレリフォーマとして機能し得る領域の容積を大きくでき、被処理ガスの滞留時間を長くできるため、被処理ガスの急激な温度上昇が抑制され、プレリフォーマとしてより好適な構造となる。更に、外管の断面積（つまり、外側流路の断面積と内管の断面積の和）が、中央部分より一端側において大きくなると、外管の外壁面の表面積が増えるため、外管の中央部分より一端側の方が他端側より、燃焼ガスの伝熱面積が増加するので、外管の断面積が一定の場合（つまり、直管の場合）と比べて、燃焼ガス温度は、外管の他端側から一方端側に向けてより顕著に低下し、プレリフォーマとしてより好適な構造となる。 According to the steam reforming system having the second feature, the volume of the region that can function as a pre-reformer on the inlet side of the outer flow path can be increased and the residence time of the gas to be processed can be increased. The rapid temperature rise is suppressed, and the structure becomes more suitable as a pre-reformer. Furthermore, if the cross-sectional area of the outer pipe (that is, the sum of the cross-sectional area of the outer flow path and the cross-sectional area of the inner pipe) becomes larger on one end side than the central portion, the surface area of the outer wall surface of the outer pipe increases. Since the heat transfer area of the combustion gas increases from one end side to the other end side from the center portion, the combustion gas temperature is as compared with the case where the cross-sectional area of the outer pipe is constant (that is, straight pipe). The outer tube is more remarkably lowered from the other end side to the one end side, and the structure becomes more suitable as a pre-reformer.
　尚、外管の断面積が、中央部分より一端側において大きくなると、当該部分の改質炉の内壁と外管の外壁の間の断面積が小さくなり、燃焼ガス流路内の外管の他端側から一端側に向けて流れる燃焼ガスの流速は、外管の一端側の方が大きくなり、燃焼ガスの対流伝熱量が増加する。燃焼ガス流路内の外管の一端側では、上述したように、燃焼ガスの放射伝熱量が低下しているので、燃焼ガスの対流伝熱量の増加により、単位伝熱面積当たりの伝熱量（熱流束）が僅かに上昇する。しかし、対流伝熱による熱流束の増加は、外側流路の入口付近でのカーボン発生に大きな影響を与える程の大きさではない。 If the cross-sectional area of the outer pipe is larger on one end side than the central part, the cross-sectional area between the inner wall of the reforming furnace and the outer wall of the outer pipe in that part becomes smaller, and the outer pipe in the combustion gas flow path The flow velocity of the combustion gas flowing from the end side toward the one end side becomes larger on the one end side of the outer tube, and the convective heat transfer amount of the combustion gas increases. As described above, the radiant heat transfer amount of the combustion gas is reduced at one end side of the outer pipe in the combustion gas flow path. Therefore, the heat transfer amount per unit heat transfer area ( Heat flux) rises slightly. However, the increase in heat flux due to convective heat transfer is not so large as to significantly affect the carbon generation near the inlet of the outer channel.
　本発明に係る水蒸気改質システムは、上記何れかの特徴に加え、前記改質器に供給される前記原料ガス中の炭素量に対する前記蒸気発生器から前記改質器に供給される水蒸気量のモル比が、１．７以上２．４以下となるように、前記改質器に供給される前記炭素量及び前記水蒸気量が調整されていることを第３の特徴とする。これにより、未分解蒸気の低減が図れる。 In addition to any of the above features, the steam reforming system according to the present invention has an amount of steam supplied from the steam generator to the reformer with respect to the amount of carbon in the raw material gas supplied to the reformer. A third feature is that the amount of carbon and the amount of water vapor supplied to the reformer are adjusted so that the molar ratio is 1.7 or more and 2.4 or less. Thereby, reduction of undecomposed steam can be achieved.
　本発明に係る水蒸気改質システムは、上記何れかの特徴に加え、内槽部の外周を外槽部が取り囲む同心円筒容器を備え、前記原料ガス中に含まれる硫黄成分を除去する脱硫器と前記変成器とが、前記外槽部と前記内槽部の何れか一方と他方に形成され、互いに熱交換可能に構成され、前記改質器と前記同心円筒容器が、前記収容空間内に、互いに隣接して、前記複数の改質管と前記同心円筒容器の夫々の軸方向を互いに平行にして、設置されていることを第４の特徴とする。 A steam reforming system according to the present invention includes, in addition to any of the above features, a desulfurizer that includes a concentric cylindrical container in which an outer tank portion surrounds the outer periphery of an inner tank portion, and removes sulfur components contained in the raw material gas. The transformer is formed in one of the outer tank part and the inner tank part and the other, and is configured to be able to exchange heat with each other, and the reformer and the concentric cylindrical container are in the storage space, A fourth feature is that the plurality of reforming tubes and the concentric cylindrical containers are installed adjacent to each other with their axial directions parallel to each other.
　上記第４の特徴を有する水蒸気改質システムによれば、先ず、脱硫器が設けられることで、低Ｓ／Ｃに起因するカーボンの発生が抑制される。更に、脱硫器と変成器が互いに熱交換可能に構成されているため、放熱損失の低減が図れるとともに、変成ガス温度の上昇を抑制でき、ＣＯ変成反応温度の安定化が図れる。更に、脱硫器と変成器が１つの同心円筒容器内に構成されているため、上記第１の特徴と同様に、改質器と変成器と脱硫器を、各部間を連絡する配管も含め、上記収容空間内に一体化して収容できるため、高温機器の外気放熱面積を小さくでき、放熱損失の低減が図れる。 According to the steam reforming system having the fourth feature, first, the generation of carbon due to low S / C is suppressed by providing the desulfurizer. Furthermore, since the desulfurizer and the transformer are configured so as to be able to exchange heat with each other, it is possible to reduce heat dissipation loss, suppress an increase in the shift gas temperature, and stabilize the CO shift reaction temperature. Furthermore, since the desulfurizer and the transformer are configured in one concentric cylindrical container, similar to the first feature, the reformer, the transformer, and the desulfurizer are also included, including piping that communicates between each part. Since it can be accommodated in the housing space, the outside air heat radiation area of the high temperature equipment can be reduced, and the heat radiation loss can be reduced.
　本発明に係る水蒸気改質システムは、上記何れかの特徴に加え、前記変成器内に、前記蒸気発生器の少なくとも一部として、前記変成器の変成反応で発生した熱を利用して前記改質器に供給する水蒸気を発生する第１蒸気発生器を備えることを第５の特徴とする。 In addition to any of the above features, the steam reforming system according to the present invention utilizes the heat generated in the shift reaction of the shift transformer as at least part of the steam generator in the shift converter. A fifth feature is that a first steam generator for generating water vapor to be supplied to the mass device is provided.
　上記第５の特徴を有する水蒸気改質システムによれば、第１蒸気発生器と変成器が互いに熱交換可能に構成されているため、放熱損失の低減が図れるとともに、変成ガス温度の上昇を抑制でき、ＣＯ変成反応温度の安定化が図れる。更に、第１蒸気発生器の水蒸気発生量を調整することで、プロセス蒸気の発生量の適正化が図れ、低Ｓ／Ｃ化を実現できる。 According to the steam reforming system having the fifth feature, since the first steam generator and the transformer are configured to be able to exchange heat with each other, it is possible to reduce heat dissipation loss and suppress an increase in the temperature of the transformed gas. It is possible to stabilize the CO shift reaction temperature. Furthermore, by adjusting the amount of steam generated by the first steam generator, the amount of process steam generated can be optimized and low S / C can be realized.
　本発明に係る水蒸気改質システムは、上記何れかの特徴に加え、前記改質炉内で発生した燃焼排ガスを前記改質炉外に排気する排気路の途中に、前記蒸気発生器の少なくとも一部として、前記燃焼排ガスの廃熱を利用して前記改質器に供給する水蒸気を発生する第２蒸気発生器を備え、前記第２蒸気発生器が、前記収容空間内に納まるように、前記改質炉の前記炉壁部の側面に沿って形成されていることを第６の特徴とする。 In addition to any of the above features, the steam reforming system according to the present invention includes at least one of the steam generators in the middle of an exhaust path for exhausting combustion exhaust gas generated in the reforming furnace to the outside of the reforming furnace. A second steam generator that generates steam to be supplied to the reformer using waste heat of the combustion exhaust gas, and the second steam generator is placed in the housing space, A sixth feature is that the reformer is formed along a side surface of the furnace wall portion of the reforming furnace.
　上記第６の特徴を有する水蒸気改質システムによれば、燃焼排ガス損失の低減が図れる。また、第２蒸気発生器を改質炉の炉壁部の側面に沿って形成することで、第２蒸気発生器を専用の熱交換器で構成する場合と比較して、熱交換表面積を低減でき、燃焼排ガス損失の低減が一層図れる。更に、第２蒸気発生器の水蒸気発生量を調整することで、プロセス蒸気の発生量の適正化が図れ、低Ｓ／Ｃ化を実現できる。更に、第１蒸気発生器と第２蒸気発生器の両方を備えた場合、第１及び第２蒸気発生器での蒸気発生量の配分を調整することで、ＣＯ変成反応の温度制御の適正化とプロセス蒸気の発生量の適正化がより容易に実現でき、低Ｓ／Ｃ化と安定した運転制御を実現できる。 According to the steam reforming system having the sixth feature, combustion exhaust gas loss can be reduced. Also, by forming the second steam generator along the side surface of the reformer furnace wall, the heat exchange surface area is reduced compared to the case where the second steam generator is configured with a dedicated heat exchanger. It is possible to further reduce the combustion exhaust gas loss. Furthermore, by adjusting the amount of steam generated by the second steam generator, the amount of process steam generated can be optimized, and low S / C can be realized. Further, when both the first steam generator and the second steam generator are provided, the temperature control of the CO shift reaction is optimized by adjusting the distribution of the steam generation amount in the first and second steam generators. Therefore, optimization of the amount of process steam generated can be realized more easily, and low S / C and stable operation control can be realized.
　本発明に係る水蒸気改質システムは、上記何れかの特徴に加え、前記改質炉の前記断熱構造体の外側面に接して鋼板製外板が設けられ、前記鋼板製外板に熱伝導可能に接して細管コイルが設けられ、前記鋼板製外板と前記細管コイルにより、前記第２蒸気発生器に供給する水を、前記改質炉の前記断熱構造体から前記鋼板製外板に伝達された熱を利用して予熱する給水予熱器が形成されていることを第７の特徴とする。 In addition to any of the above features, the steam reforming system according to the present invention is provided with a steel plate outer plate in contact with the outer surface of the heat insulating structure of the reforming furnace, and can conduct heat to the steel plate outer plate. A thin tube coil is provided in contact with the steel plate, and water supplied to the second steam generator is transmitted from the heat insulating structure of the reforming furnace to the steel plate outer plate by the steel plate outer plate and the thin tube coil. A seventh feature is that a feed water preheater that preheats using the generated heat is formed.
　上記第７の特徴を有する水蒸気改質システムによれば、鋼板製外板により、改質炉内の燃焼ガスの循環滞留熱損失を抑制できるとともに、燃焼排ガスの廃熱を有効に回収できるため、燃焼排ガス損失の低減が図れる。また、鋼板製外板に接して給水予熱器を形成することで、鋼板製外板を被覆する保温材を厚くしなくても十分な保温性能が実現できる。 According to the steam reforming system having the seventh feature, the steel plate outer plate can suppress the circulation residence heat loss of the combustion gas in the reforming furnace and can effectively recover the waste heat of the combustion exhaust gas. Reduction of combustion exhaust gas loss can be achieved. Further, by forming the feed water preheater in contact with the steel plate outer plate, sufficient heat insulating performance can be realized without increasing the thickness of the heat insulating material covering the steel plate outer plate.
　本発明に係る水蒸気改質システムは、上記何れかの特徴に加え、前記改質炉内で発生した燃焼排ガスを前記改質炉外に排気する排気路の途中に、前記燃焼排ガスの廃熱を利用して、前記燃焼器に供給する燃料ガス及び燃焼空気を予熱するガス予熱器と空気予熱器を備え、前記ガス予熱器と前記空気予熱器が、前記収容空間内に納まるように、前記改質炉の前記断熱構造体の側面に沿って形成されていることを第８の特徴とする。 In addition to any of the above features, the steam reforming system according to the present invention is configured to dispose the waste heat of the combustion exhaust gas in the middle of an exhaust path for exhausting the combustion exhaust gas generated in the reforming furnace to the outside of the reforming furnace. A gas preheater and an air preheater for preheating the fuel gas and combustion air supplied to the combustor, and the gas preheater and the air preheater are placed in the housing space. An eighth feature is that the heat insulating structure is formed along the side surface of the quality furnace.
　上記第８の特徴を有する水蒸気改質システムによれば、燃焼排ガス損失の低減が図れる。また、ガス予熱器と空気予熱器を改質炉の断熱構造体の側面に沿って形成することで、ガス予熱器と空気予熱器を専用の熱交換器で構成する場合と比較して、熱交換表面積を低減でき、燃焼排ガス損失の低減が一層図れる。 According to the steam reforming system having the eighth feature, combustion exhaust gas loss can be reduced. In addition, by forming the gas preheater and air preheater along the side surface of the heat insulating structure of the reforming furnace, compared with the case where the gas preheater and air preheater are configured with dedicated heat exchangers, The exchange surface area can be reduced and combustion exhaust gas loss can be further reduced.
　本発明に係る水蒸気改質システムは、上記何れかの特徴に加え、前記変成ガス中に含まれる水素以外のガスを吸着除去し、前記変成ガスより含有水素濃度の上昇した製品水素を生成するＰＳＡ分離装置を、前記収容空間外に備えることを第９の特徴とする。 In addition to any of the above features, the steam reforming system according to the present invention absorbs and removes a gas other than hydrogen contained in the modified gas, and generates product hydrogen having an increased hydrogen concentration from the modified gas. A ninth feature is that a separation device is provided outside the accommodation space.
　上記第９の特徴を有する水蒸気改質システムによれば、変成ガス中に含まれるＣＯ、ＣＯ２、ＣＨ４等の水素以外のガスが除去された高純度の製品水素ガスが得られる。また、当該除去された水素以外のガス（オフガス）が回収され、燃料ガスとして再利用されることで、熱効率が向上する。 According to the steam reforming system having the ninth feature, a high-purity product hydrogen gas from which gases other than hydrogen such as CO, CO 2 , and CH 4 contained in the modified gas are removed can be obtained. Further, the gas other than the removed hydrogen (off-gas) is recovered and reused as a fuel gas, so that the thermal efficiency is improved.
　本発明に係る水蒸気改質システムは、上記第９の特徴に加え、前記ＰＳＡ分離装置が備える複数の吸着槽の夫々が、前記変成ガス中に含まれる一酸化炭素を化学的に吸着する化学吸着剤を備えることを第１０の特徴とする。 In the steam reforming system according to the present invention, in addition to the ninth feature described above, each of the plurality of adsorption tanks provided in the PSA separation apparatus chemically adsorbs carbon monoxide contained in the metamorphic gas. The tenth feature is to provide an agent.
　上記第１０の特徴を有する水蒸気改質システムによれば、化学吸着剤が、物理的な吸着剤と比較してＣＯに対する吸着能力が高いため、吸着剤の占める容積を低減できるため、オフガス量が少なくなって水素回収率を向上できる。また、オフガス量が減少することで、オフガスに起因する熱損失が低減される。 According to the steam reforming system having the tenth feature described above, since the chemical adsorbent has a higher adsorption capacity for CO as compared with a physical adsorbent, the volume occupied by the adsorbent can be reduced. The amount of hydrogen recovered can be reduced. Moreover, the heat loss resulting from offgas is reduced by reducing the amount of offgas.
　本発明に係る水蒸気改質システムは、上記第９または第１０の特徴に加え、前記ＰＳＡ分離装置が、３槽の吸着槽と真空ポンプと補圧ポンプを備え、前記真空ポンプと前記補圧ポンプが、同じ真空ポンプを兼用して構成されるか、或いは、個別のポンプで夫々構成され、前記３槽の吸着槽の内の第１槽が吸着処理に供される１サイクルが４工程で構成され、
　前記ＰＳＡ分離装置が、前記１サイクルの間、
　第１工程で、前記３槽の吸着槽の内の第２槽と第３槽の槽内圧を均等化するために、前記第２及び第３槽の槽内間を連通させ、前記第２槽を減圧し、前記第３槽を昇圧し、
　第２工程で、前記第２及び第３槽の槽内間を、前記捕圧ポンプを介して連通させ、前記第２槽を更に減圧し、前記第３槽を更に昇圧し、
　第３工程で、前記第３槽を、前記製品水素の一部の水素を用いて加圧し、前記第２槽内に吸着された前記水素以外のガスを、前記真空ポンプを作動させて真空脱着してオフガスとして排出し、
　第４工程で、前記第３槽に対する加圧を停止し、前記第２槽に対して、前記製品水素の一部の水素を用いて、吸着剤の洗浄と残留ガスのパージ処理を行うように構成されていることを第１１の特徴とする。 In the steam reforming system according to the present invention, in addition to the ninth or tenth feature, the PSA separation apparatus includes three adsorption tanks, a vacuum pump, and a supplementary pressure pump, and the vacuum pump and the supplementary pressure pump However, the same vacuum pump is also used, or each pump is composed of individual pumps, and one cycle in which the first tank among the three tanks is subjected to the adsorption process is composed of four steps. And
During the one cycle, the PSA separator
In the first step, in order to equalize the internal pressure of the second tank and the third tank among the three adsorption tanks, the second tank and the third tank are communicated with each other, and the second tank The pressure in the third tank,
In the second step, the inside of the tanks of the second and third tanks are communicated via the pressure pump, the second tank is further depressurized, the third tank is further pressurized,
In the third step, the third tank is pressurized using a part of the product hydrogen, and the gas other than the hydrogen adsorbed in the second tank is vacuum desorbed by operating the vacuum pump. And exhaust it as off-gas,
In the fourth step, pressurization to the third tank is stopped, and cleaning of the adsorbent and purging of residual gas are performed on the second tank by using a part of the hydrogen of the product hydrogen. The eleventh feature is that it is configured.
　上記第１１の特徴を有する水蒸気改質システムによれば、第２工程の補圧処理と第３工程の真空脱着処理を経てパージを行うことで、従来のＰＳＡ水素分離において脱着及びパージに使用されていた水素量を大幅に削減でき、水素回収率の向上が図れる。 According to the steam reforming system having the eleventh feature described above, the purge is performed through the second pressure compensation process and the third process vacuum desorption process, so that it is used for desorption and purge in the conventional PSA hydrogen separation. The amount of hydrogen used can be greatly reduced, and the hydrogen recovery rate can be improved.
　更に、本発明に係る発電システムは、上記何れかの特徴を有する水蒸気改質システムを備える水素製造システムと、前記水素製造システムが生成する水素を消費して発電する発電装置を備え、前記水素製造システムの水素ガス化効率が９０％以上であることを第１の特徴とする。 Furthermore, a power generation system according to the present invention includes a hydrogen production system including a steam reforming system having any of the above characteristics, and a power generation device that consumes hydrogen generated by the hydrogen production system to generate power, and The first feature is that the hydrogen gasification efficiency of the system is 90% or more.
　上記第１の特徴を有する発電システムによれば、発電装置として、近年発電効率が５０％以上に向上した固体高分子形燃料電池（ＰＥＦＣ）等を採用することで、発電システム全体として、極めて高い発電効率が得られる。例えば、発電装置の発電効率が５０％と仮定し、水素製造システムの水素ガス化効率が９０％として直交変換効率や自家消費電力を考慮すると、その送電端効率（ＨＨＶ）は４４％程度になり、天然ガスのガスタービンコンバインドサイクル（ＧＴＣＣ）発電に匹敵する発電効率となる。 According to the power generation system having the first feature described above, by adopting a polymer electrolyte fuel cell (PEFC) or the like whose power generation efficiency has been improved to 50% or more in recent years, the power generation system as a whole is extremely high. Power generation efficiency can be obtained. For example, assuming that the power generation efficiency of the power generation device is 50% and the hydrogen gasification efficiency of the hydrogen production system is 90%, considering the orthogonal transformation efficiency and private power consumption, the power transmission end efficiency (HHV) is about 44%. The power generation efficiency is comparable to natural gas gas turbine combined cycle (GTCC) power generation.
　本発明に係る発電システムは、上記第１の特徴に加え、前記水素製造システムが、水素を燃料とする車両用の水素供給基地における水素供給設備を構成し、前記発電装置が、前記水素供給基地内に設けられた、電気自動車に電力を供給する電力供給設備を構成することを第２の特徴とする。 In the power generation system according to the present invention, in addition to the first feature, the hydrogen production system constitutes a hydrogen supply facility in a hydrogen supply base for vehicles using hydrogen as a fuel, and the power generation device includes the hydrogen supply base. A second feature is that a power supply facility for supplying electric power to the electric vehicle is provided.
　上記第２の特徴を有する発電システムによれば、例えば、燃料電池自動車（ＦＣＶ）用のサテライト水素供給基地において、発電装置の発電電力を、電気自動車に向けに供給することで、高い稼働率が実現できる。また、当該発電電力は、水素の圧縮電力にも利用でき、外販も可能である。 According to the power generation system having the second feature described above, for example, in a satellite hydrogen supply base for a fuel cell vehicle (FCV), the generated power of the power generation device is supplied to the electric vehicle, so that a high operation rate is achieved. realizable. In addition, the generated power can be used for compressed hydrogen power and can be sold externally.
　本発明に係る水蒸気改質システムによれば、熱損失を効果的に抑制でき、カーボン発生の抑制された低Ｓ／Ｃ運転が可能となり、８０％以上好ましくは９０％以上の水素ガス化効率を達成し得る。 According to the steam reforming system of the present invention, heat loss can be effectively suppressed, low S / C operation with suppressed carbon generation is possible, and hydrogen gasification efficiency of 80% or more, preferably 90% or more is achieved. Can be achieved.
本発明に係る水蒸気改質システムの一実施形態における概略構成を模式的に示す構成図The block diagram which shows typically the schematic structure in one Embodiment of the steam reforming system which concerns on this invention 図１に示す水蒸気改質システムのＣＯ変成器までの前段部の組立構造を模式的に示す筒状の収容空間の軸心に垂直な断面と該軸心を通過する断面における断面図Sectional drawing in the cross section perpendicular | vertical to the axial center of the cylindrical accommodating space which shows typically the assembly structure of the front | former part to the CO converter of the steam reforming system shown in FIG. 1, and the cross section which passes through this axial center 図２に示す水蒸気改質システムの改質管の組立構造を模式的に示す改質管の軸心を通過する断面における断面図Sectional drawing in the cross section which passes along the axial center of the reforming pipe | tube which shows typically the assembly structure of the reforming pipe | tube of the steam reforming system shown in FIG. 図２に示す水蒸気改質システムの改質炉に設けた廃熱回収機器の概略構成を模式的に示す展開図FIG. 2 is a development view schematically showing the schematic configuration of the waste heat recovery equipment provided in the reforming furnace of the steam reforming system shown in FIG. 図１に示す水蒸気改質システムのＰＳＡ水素分離装置の概略構成及び１サイクル中の弁の開閉状態を模式的に示す構成図Schematic configuration of the PSA hydrogen separator of the steam reforming system shown in FIG. 1 and a configuration diagram schematically showing the open / close state of the valve during one cycle 図５に示すＰＳＡ水素分離装置の１サイクル中の各槽の圧力変化を模式的に示す図The figure which shows typically the pressure change of each tank in 1 cycle of the PSA hydrogen separation apparatus shown in FIG. 本発明に係る水蒸気改質システムの予想運転成績を比較した一覧表Table comparing the expected operating results of the steam reforming system according to the present invention 水蒸気改質システムの条件別の予想運転成績を比較した一覧表A table comparing the expected operating results of steam reforming systems by conditions 図８に示す条件別の予想運転成績における各種損失と水素ガス化効率の構成比率を示す棒グラフA bar graph showing the composition ratio of various losses and hydrogen gasification efficiency in the predicted operating results by conditions shown in FIG. 従来の水素製造システムの概略構成を模式的に示す構成図Schematic diagram showing the schematic configuration of a conventional hydrogen production system 図１０に示す従来の水素製造システムの熱収支例を示すエネルギ収支図Energy balance diagram showing a heat balance example of the conventional hydrogen production system shown in FIG. 水素製造における物質の移動を簡略的に示す図Diagram showing the movement of substances in hydrogen production 図１０に示す従来の水素製造システムにおける流体の温度と燃焼ガスのエンタルピの関係により熱損失の分布の一例を示す熱損失分析図Heat loss analysis diagram showing an example of heat loss distribution according to the relationship between the temperature of the fluid and the enthalpy of the combustion gas in the conventional hydrogen production system shown in FIG.
　本発明に係る水蒸気改質システムの実施形態（以下、適宜、「本実施形態」と称す。）につき、図面に基づいて説明する。 Embodiments of a steam reforming system according to the present invention (hereinafter referred to as “this embodiment” as appropriate) will be described with reference to the drawings.
　本実施形態に係る水蒸気改質システム１は、図１に模式的に示すように、原料圧縮機１１、脱硫器１２、第１給水予熱器１３、第２給水予熱器１４、第１水蒸気発生器１５、第２水蒸気発生器１６、改質炉１７、改質管１８、バーナ１９（燃焼器に相当）、ガス予熱器２０、空気予熱器２１、ＣＯ変成器２２、ガス冷却器２３、ドレイン分離器２４、ＰＳＡ水素分離装置２５等を備えて構成される。図１では、水蒸気改質システム１を構成する機器と当該機器間の物質（原料ガス、燃料ガス、純水、水蒸気、燃焼空気、燃焼排ガス、改質ガス、変成ガス、製品水素ガス、オフガス、脱硫用水素）の流れを示している。 As schematically shown in FIG. 1, the steam reforming system 1 according to this embodiment includes a raw material compressor 11, a desulfurizer 12, a first feed water preheater 13, a second feed water preheater 14, and a first steam generator. 15, second steam generator 16, reforming furnace 17, reforming pipe 18, burner 19 (corresponding to a combustor), gas preheater 20, air preheater 21, CO converter 22, gas cooler 23, drain separation And a PSA hydrogen separator 25 and the like. In FIG. 1, the components between the devices constituting the steam reforming system 1 and the devices (raw gas, fuel gas, pure water, steam, combustion air, combustion exhaust gas, reformed gas, modified gas, product hydrogen gas, off gas, This shows the flow of hydrogen for desulfurization.
　次に、図２及び図３を参照して、改質器を構成する改質炉１７と改質管１８の詳細な構造について説明する。図２は、２点鎖線で示される円筒状の収容空間１０内に、脱硫器１２、第１給水予熱器１３、第２給水予熱器１４、第１水蒸気発生器１５、第２水蒸気発生器１６、改質炉１７、改質管１８、バーナ１９、ガス予熱器２０、空気予熱器２１、及び、ＣＯ変成器２２の高温設備機器と、当該機器間を連絡する配管を一体化して組み立てる組立構造を示している。図２（Ａ）は、円筒状の収容空間１０の軸心に垂直な断面における当該組立構造を示し、図２（Ｂ）は、同軸心を通過するＡ－Ａ’断面における当該組立構造を示している。図３は、改質管１８を外管２６と内管２７の同軸２重管で構成した組立構造を模式的に示す図で、改質管１８の軸心を通過する断面における模式的な断面図である。尚、本実施形態では、図２（Ｂ）及び図３における上側が、改質炉１７、改質管１８（外管２６と内管２７）、及び、円筒状の収容空間１０の「一端側」に相当し、下側が、改質炉１７、改質管１８（外管２６と内管２７）、及び、円筒状の収容空間１０の「他端側」に相当する。 Next, the detailed structure of the reforming furnace 17 and the reforming pipe 18 constituting the reformer will be described with reference to FIGS. FIG. 2 shows a desulfurizer 12, a first feed water preheater 13, a second feed water preheater 14, a first steam generator 15, and a second steam generator 16 in a cylindrical housing space 10 indicated by a two-dot chain line. , Reforming furnace 17, reforming pipe 18, burner 19, gas preheater 20, air preheater 21, and CO converter 22, and an assembly structure that integrally assembles the piping that communicates between the devices. Is shown. 2A shows the assembly structure in a cross section perpendicular to the axis of the cylindrical accommodation space 10, and FIG. 2B shows the assembly structure in a cross section AA ′ passing through the coaxial core. ing. FIG. 3 is a diagram schematically showing an assembly structure in which the reforming pipe 18 is constituted by a coaxial double pipe of an outer pipe 26 and an inner pipe 27, and a schematic cross section in a cross section passing through the axis of the reforming pipe 18. FIG. In the present embodiment, the upper side in FIGS. 2B and 3 is the “one end side” of the reforming furnace 17, the reforming pipe 18 (the outer pipe 26 and the inner pipe 27), and the cylindrical housing space 10. The lower side corresponds to the “other end side” of the reforming furnace 17, the reforming pipe 18 (the outer pipe 26 and the inner pipe 27), and the cylindrical accommodation space 10.
　図２（Ａ）に示すように、改質炉１７は、収容空間１０の軸心に垂直な平面内において、収容空間１０内の略扇型の余剰スペースを除く部分に形成されている。当該余剰スペースは、収容空間１０の外周の約４分の１の円弧部分を含む収容空間１０内の一部分である。尚、当該余剰スペースには、後述するように、脱硫器１２、第１給水予熱器１３、第１水蒸気発生器１５、及び、ＣＯ変成器２２が設置される。改質炉１７は、耐火煉瓦等の断熱材からなる断熱構造体（炉壁部、炉頂部、炉底部）で側面、上面及び下面を囲まれた改質炉内に、５本の改質管１８が収容されている。５本の改質管１８は全く同じ構造、形状及び寸法で構成されている。図２（Ａ）では、５本の改質管１８が異なる管径で簡略表示されている箇所は、管径の異なる断面を図示している。５本の改質管１８は、改質炉１７の断熱構造体の上面に設けられた５つの開口部から、改質炉内に挿入されている。各改質管１８の入口は入口配管により、出口は出口配管により、夫々、炉頂部の上側で、相互に接続され連通している。改質炉内の空間の上面視形状は、略“Ｃ”形（ドーナツの４分の１ほどを切り欠いた形状）をしており、この“Ｃ”の形状の円弧状の中心線に沿って、５本の改質管１８が配置されている。 As shown in FIG. 2 (A), the reforming furnace 17 is formed in a portion excluding a substantially fan-shaped surplus space in the accommodation space 10 in a plane perpendicular to the axis of the accommodation space 10. The surplus space is a part of the accommodation space 10 including an arc part of about one quarter of the outer periphery of the accommodation space 10. In the surplus space, as will be described later, a desulfurizer 12, a first feed water preheater 13, a first steam generator 15, and a CO converter 22 are installed. The reforming furnace 17 includes five reforming pipes in a reforming furnace surrounded by a heat insulating structure (furnace wall, furnace top, furnace bottom) made of a heat insulating material such as refractory bricks, with its side surface, upper surface and lower surface surrounded. 18 is housed. The five reforming tubes 18 have the same structure, shape and dimensions. In FIG. 2A, the portions where the five reforming pipes 18 are simply displayed with different pipe diameters show cross sections having different pipe diameters. The five reforming tubes 18 are inserted into the reforming furnace from five openings provided on the upper surface of the heat insulating structure of the reforming furnace 17. The inlets of the reforming pipes 18 are connected to and communicated with each other on the upper side of the furnace top portion through an inlet pipe and an outlet through an outlet pipe, respectively. The top view of the space in the reforming furnace has a substantially “C” shape (a shape in which about a quarter of the donut is cut out), and follows the arc-shaped center line of this “C” shape. Thus, five reforming pipes 18 are arranged.
　バーナ１９は、改質炉１７の炉壁部の下端部を貫通して設けられており、バーナ１９による燃料ガスの燃焼によって生成された燃焼ガスが、５本の改質管１８の各外管２６の外壁面と改質炉１７の炉壁部の内壁面との間に形成される燃焼ガス流路を、下側から上側に向けて通流するように構成されている。尚、バーナ１９は、炉壁部の下端部ではなく、改質炉１７内の炉底部に設置しても良い。 The burner 19 is provided so as to penetrate the lower end portion of the furnace wall portion of the reforming furnace 17, and the combustion gas generated by the combustion of the fuel gas by the burner 19 is provided for each outer pipe of the five reforming pipes 18. A combustion gas passage formed between the outer wall surface of 26 and the inner wall surface of the furnace wall portion of the reforming furnace 17 is configured to flow from the lower side toward the upper side. The burner 19 may be installed not at the lower end of the furnace wall but at the furnace bottom in the reforming furnace 17.
　図２（Ｂ）及び図３に示すように、各改質管１８の底部は、外管２６の下端を球面状の蓋部材２８で遮閉して形成されており、改質炉１７の炉底部に形成された球面状の凹部に蓋部材２８の下面が接して支持されている。また、外管２６の上端の外側面とフランジ部下面が当該開口部の内側面と外周上面と気密に接し、外管２６の上側の開口は、一部球面状の蓋部材２９で遮閉され、当該上側の蓋部材２９には、外管２６と内管２７の間の外側流路３０に原料ガスと水蒸気の混合ガスを供給する入口を形成する入口管３２が設けられている。各改質管１８の入口管３２は、夫々、共通の入口配管３６に接続している。 As shown in FIGS. 2B and 3, the bottom portion of each reformer tube 18 is formed by blocking the lower end of the outer tube 26 with a spherical lid member 28. The bottom surface of the lid member 28 is in contact with and supported by a spherical recess formed at the bottom. The outer surface of the upper end of the outer tube 26 and the lower surface of the flange portion are in airtight contact with the inner surface of the opening and the upper surface of the outer periphery, and the upper opening of the outer tube 26 is partially blocked by a spherical lid member 29. The upper lid member 29 is provided with an inlet pipe 32 that forms an inlet for supplying a mixed gas of raw material gas and water vapor to the outer flow path 30 between the outer pipe 26 and the inner pipe 27. The inlet pipe 32 of each reforming pipe 18 is connected to a common inlet pipe 36.
　内管２７の内側には、内側流路３１が形成されている。図２（Ｂ）及び図３に示すように、内管２７の下端は開口し、当該開口と外管２６内の外側流路３０と蓋部材２８の間の下部空間３４を介して、外側流路３０と内側流路３１が連通している。内管２７の上側の開口は、平板状の蓋部材３５で遮閉され、当該上側の蓋部材３５には、上記混合ガスが外側流路３０を通過中に改質され生成された改質ガスを、内側流路３１を通して外部に送出する出口管３３が設けられている。出口管３３は、内側流路３１から蓋部材３５と蓋部材２９を貫通して外部に突出している。各改質管１８の出口管３３は、夫々、共通の出口配管３７に接続している。 An inner flow path 31 is formed inside the inner tube 27. As shown in FIGS. 2B and 3, the lower end of the inner tube 27 is opened, and the outer flow is passed through the lower space 34 between the opening and the outer flow path 30 in the outer tube 26 and the lid member 28. The path 30 and the inner flow path 31 communicate with each other. The upper opening of the inner tube 27 is shielded by a flat lid member 35, and the reformed gas generated by reforming the mixed gas while passing through the outer flow path 30 is generated in the upper lid member 35. Is provided through the inner flow path 31 to the outside. The outlet pipe 33 projects from the inner flow path 31 through the lid member 35 and the lid member 29 to the outside. The outlet pipe 33 of each reforming pipe 18 is connected to a common outlet pipe 37.
　本実施形態では、各改質管１８の上側（一端側）に入口管３２と出口管３３が設けられており、入口管３２から外側流路３０に送入された被処理ガス（混合ガス）は、外側流路３０内を下向きに通過し、外側流路３０及び下部空間３４内で改質され、改質後の改質ガスが、下部空間３４内で流れの向きを反転して、内側流路３１内を上向きに通過して、出口管３３から出口配管３７へと送出される。ここで、上述のように、燃焼ガスが、各外管２６の外壁と改質炉１７の内壁面の間の燃焼ガス流路を、下側から上側に向けて通流するため、燃焼ガスの熱が外管２６の管壁に吸収され、燃焼ガス温度は、下側から上側に向けて低下する。同様に、内側流路３１内を上向きに通過する改質ガスも、改質ガスの熱が内管２７の管壁に吸収され、改質ガス温度は、下側から上側に向けて低下する。この結果、外管２６と内管２７の管壁を通過して、外側流路３０内に伝導する単位伝熱面積当たりの伝熱量（熱流束）は、上側ほど少なくなり、外側流路３０の上端部分では、被処理ガスの温度上昇が緩やかなものになり、プレリフォーマとして機能し、低Ｓ／Ｃ運転に起因するカーボン析出を抑制できる。 In the present embodiment, an inlet pipe 32 and an outlet pipe 33 are provided on the upper side (one end side) of each reforming pipe 18, and a gas to be processed (mixed gas) sent from the inlet pipe 32 to the outer flow path 30. Passes through the outer flow path 30 downward and is reformed in the outer flow path 30 and the lower space 34, and the reformed gas after reforming reverses the flow direction in the lower space 34, It passes through the flow path 31 upward and is sent from the outlet pipe 33 to the outlet pipe 37. Here, as described above, the combustion gas flows through the combustion gas flow path between the outer wall of each outer pipe 26 and the inner wall surface of the reforming furnace 17 from the lower side to the upper side. Heat is absorbed by the tube wall of the outer tube 26, and the combustion gas temperature decreases from the lower side toward the upper side. Similarly, also in the reformed gas passing upward in the inner flow path 31, the heat of the reformed gas is absorbed by the tube wall of the inner tube 27, and the reformed gas temperature decreases from the lower side toward the upper side. As a result, the heat transfer amount (heat flux) per unit heat transfer area that passes through the outer pipe 26 and the inner pipe 27 and is conducted into the outer flow path 30 decreases toward the upper side. At the upper end portion, the temperature rise of the gas to be treated becomes gradual, functions as a pre-reformer, and can suppress carbon precipitation caused by low S / C operation.
　外管２６と内管２７の外径は、軸心方向の略中央部分で、上側に向かって拡径しており、当該拡径部分の上側の方が、当該拡径部分の下側より大きくなっている。一例として、標準の水素製造量として３００ｍ３Ｎ／ｈを想定した場合に使用される改質管１８では、上側部分の外管２６と内管２７の外径は、夫々、約３１８ｍｍと約２１６ｍｍで、管壁の厚さは、夫々、約１０ｍｍと約２．８ｍｍである。下側部分の外管２６と内管２７の外径は、夫々、約２１６ｍｍと約１４０ｍｍで、管壁の厚さは、夫々、約８ｍｍと約２．８ｍｍである。従って、外管２６と内管２７は、夫々、ビール瓶を逆さにしたような形状となっている。以下、本実施形態における改質管１８の構造を、便宜的に「逆ボトル型２重管構造」と呼ぶ。尚、図３では、図２（Ｂ）と異なり、同軸２重管構造を簡易に説明するために、縦方向の縮尺を、横方向に比べて大幅に圧縮して表示しており、実際の寸法比とは大きく異なる。また、上述の水素製造量を想定した場合、例えば、円筒状の収容空間１０の直径は２ｍ、高さは３．１５ｍとなる。 The outer diameters of the outer tube 26 and the inner tube 27 are expanded toward the upper side at a substantially central portion in the axial direction, and the upper side of the expanded diameter portion is larger than the lower side of the expanded diameter portion. It has become. As an example, in the reforming pipe 18 used when assuming a standard hydrogen production amount of 300 m 3 N / h, the outer diameters of the outer pipe 26 and the inner pipe 27 in the upper portion are about 318 mm and about 216 mm, respectively. The thickness of the tube wall is about 10 mm and about 2.8 mm, respectively. The outer diameters of the outer tube 26 and the inner tube 27 in the lower part are about 216 mm and about 140 mm, respectively, and the thickness of the tube wall is about 8 mm and about 2.8 mm, respectively. Accordingly, the outer tube 26 and the inner tube 27 are each shaped like an inverted beer bottle. Hereinafter, the structure of the reforming pipe 18 in the present embodiment is referred to as a “reverse bottle type double pipe structure” for convenience. In FIG. 3, unlike FIG. 2 (B), in order to simply explain the coaxial double-pipe structure, the scale in the vertical direction is displayed by being greatly compressed compared to the horizontal direction. It is very different from dimensional ratio. Further, assuming the above-described hydrogen production amount, for example, the cylindrical accommodation space 10 has a diameter of 2 m and a height of 3.15 m.
　本実施形態では、当該逆ボトル型２重管構造を採用することで、外側流路３０の入口側のプレリフォーマとして機能する領域の容積を大きくでき、被処理ガスの滞留時間を長くできるため、被処理ガスの急激な温度上昇が抑制され、プレリフォーマとしてより好適な構造となる。 In this embodiment, by adopting the reverse bottle type double pipe structure, the volume of the region functioning as a pre-reformer on the inlet side of the outer flow path 30 can be increased, and the residence time of the gas to be processed can be increased. The rapid increase in temperature of the gas to be processed is suppressed, and the structure becomes more suitable as a pre-reformer.
　ところで、当該逆ボトル型２重管構造により、各外管２６の外壁と改質炉１７の内壁面の間の燃焼ガス流路は、上記拡径部分より上側で狭くなっているため、上側に向かって流れる燃焼ガスの流速は、当該狭窄箇所で大きくなり、燃焼ガスの対流伝熱量が増加する。しかし、改質炉１７内の伝熱は放射伝熱が主であるため、対流伝熱量の増加によって、カーボン析出の抑制効果が損なわれる程度ではない。 By the way, because of the reverse bottle type double pipe structure, the combustion gas flow path between the outer wall of each outer pipe 26 and the inner wall surface of the reforming furnace 17 is narrower on the upper side than the above-mentioned enlarged diameter portion. The flow velocity of the combustion gas flowing in the direction increases at the narrowed portion, and the convective heat transfer amount of the combustion gas increases. However, since the heat transfer in the reforming furnace 17 is mainly radiant heat transfer, the effect of suppressing carbon deposition is not impaired by the increase in the amount of convective heat transfer.
　本実施形態では、外側流路３０と下部空間３４内に改質触媒が充填されており、内側流路３１内には、アルミナ等のイナートの粒体が充填されている。尚、下部空間３４内に改質触媒が充填されていなくても良く、また、内側流路３１の下端部の一部に、少量の改質触媒が充填されていても構わない。改質触媒としては、Ｒｕ系触媒、Ｎｉ系触媒等の使用が想定されるが、これらに限定されるものではない。 In this embodiment, the reforming catalyst is filled in the outer flow path 30 and the lower space 34, and the inner flow path 31 is filled with inert particles such as alumina. The lower space 34 may not be filled with the reforming catalyst, and a part of the lower end portion of the inner flow path 31 may be filled with a small amount of the reforming catalyst. As the reforming catalyst, use of a Ru-based catalyst, a Ni-based catalyst, or the like is assumed, but is not limited thereto.
　次に、図２を参照して、脱硫器１２、ＣＯ変成器２２、第１給水予熱器１３、及び、第１水蒸気発生器１５の概略構造について説明する。上述したように、脱硫器１２、ＣＯ変成器２２、第１給水予熱器１３、及び、第１水蒸気発生器１５は、収容空間１０の軸心に垂直な平面内において、収容空間１０内の改質炉１７が形成された領域を除く余剰スペース内に設置されている。本実施形態では、脱硫器１２とＣＯ変成器２２と第１水蒸気発生器１５は、余剰スペース内にコンパクトに収まるように一体化されている。 Next, the schematic structure of the desulfurizer 12, the CO converter 22, the first feed water preheater 13, and the first steam generator 15 will be described with reference to FIG. As described above, the desulfurizer 12, the CO converter 22, the first feed water preheater 13, and the first steam generator 15 are modified in the storage space 10 in a plane perpendicular to the axis of the storage space 10. It is installed in an extra space excluding the region where the quality furnace 17 is formed. In the present embodiment, the desulfurizer 12, the CO transformer 22, and the first steam generator 15 are integrated so as to fit in the surplus space in a compact manner.
　図２に示すように、脱硫器１２とＣＯ変成器２２は、内槽部の外周を外槽部が取り囲む同心円筒容器を備えて構成され、外槽部に脱硫触媒（例えば、超高次脱硫触媒）を充填して脱硫器１２を形成し、内槽部にＣＯ変成触媒（例えば、銅亜鉛系触媒）を充填してＣＯ変成器２２を形成している。更に、内槽部のＣＯ変成触媒内に除熱兼蒸気発生用のコイル配管を装填し、第１水蒸気発生器１５を内槽部内に形成している。第１給水予熱器１３は、給水源から供給される純水を、ＣＯ変成器２２で生成された高温の変成ガスと熱交換により予熱するプレート式の熱交換器である。尚、第１給水予熱器１３は、余剰スペース内の外槽部と改質炉１７の間隙に設置されている。 As shown in FIG. 2, the desulfurizer 12 and the CO converter 22 are configured to include a concentric cylindrical container in which the outer tank portion surrounds the outer periphery of the inner tank portion, and a desulfurization catalyst (for example, ultrahigh-order desulfurization) The desulfurizer 12 is formed by filling the catalyst), and the CO shifter 22 is formed by filling the inner tank portion with a CO shift catalyst (for example, a copper zinc catalyst). Furthermore, coil piping for heat removal and steam generation is loaded into the CO conversion catalyst in the inner tank portion, and the first water vapor generator 15 is formed in the inner tank portion. The first feed water preheater 13 is a plate-type heat exchanger that preheats pure water supplied from a feed water source by heat exchange with the high-temperature shift gas generated by the CO shift converter 22. In addition, the 1st water supply preheater 13 is installed in the clearance gap between the outer tank part in the surplus space, and the reforming furnace 17. FIG.
　外槽部の一端側に設けられた脱硫器１２の入口が、配管を介して原料圧縮機１１の出口と接続され、外槽部の他端側に設けられた脱硫器１２の出口が、入口配管３６を介して各改質管１８の入口管３２と接続される。内槽部の一端側に設けられたＣＯ変成器２２の入口が、出口配管３７を介して各改質管１８の出口管３３と接続され、内槽部の他端側に設けられたＣＯ変成器２２の出口が、配管を介して第１給水予熱器１３のガス入口と接続される。 The inlet of the desulfurizer 12 provided on one end side of the outer tub portion is connected to the outlet of the raw material compressor 11 via a pipe, and the outlet of the desulfurizer 12 provided on the other end side of the outer tub portion is an inlet. The pipes 36 are connected to the inlet pipes 32 of the respective reforming pipes 18. The CO converter 22 provided at one end of the inner tank is connected to the outlet pipe 33 of each reforming pipe 18 via the outlet pipe 37, and the CO converter provided at the other end of the inner tank. The outlet of the vessel 22 is connected to the gas inlet of the first feed water preheater 13 via a pipe.
　第１水蒸気発生器１５のコイル配管の入口側の一端は、配管を介して第１給水予熱器１３の給水出口と接続される。第１水蒸気発生器１５のコイル配管の出口側の他端は、分岐配管を介して入口配管３６に接続され、第１水蒸気発生器１５で生成された水蒸気と、脱硫器１２で脱硫処理された原料ガスとが混合される。第１給水予熱器１３の給水入口には、給水源から純水が供給される。第１給水予熱器１３のガス出口は、配管を介して、収容空間１０外に設けられたガス冷却器２３のガス入口と接続される。 One end of the coil pipe of the first steam generator 15 on the inlet side is connected to the feed outlet of the first feed water preheater 13 through the pipe. The other end of the coil pipe of the first steam generator 15 on the outlet side is connected to the inlet pipe 36 via a branch pipe, and the steam generated by the first steam generator 15 and the desulfurizer 12 are desulfurized. The raw material gas is mixed. Pure water is supplied from the water supply source to the water supply inlet of the first water supply preheater 13. A gas outlet of the first feed water preheater 13 is connected to a gas inlet of a gas cooler 23 provided outside the accommodation space 10 via a pipe.
　次に、図４を参照して、改質炉１７の断熱構造と、第２給水予熱器１４、第２水蒸気発生器１６、ガス予熱器２０、及び、空気予熱器２１の詳細な構造について説明する。図４は、改質炉１７の炉壁部、炉頂部、及び、炉底部に設けられた廃熱回収機器（第２給水予熱器１４、第２水蒸気発生器１６、ガス予熱器２０、空気予熱器２１）を模式的に示す展開図である。 Next, with reference to FIG. 4, the heat insulation structure of the reforming furnace 17 and the detailed structures of the second feed water preheater 14, the second steam generator 16, the gas preheater 20, and the air preheater 21 will be described. To do. FIG. 4 shows the waste heat recovery equipment (second feed water preheater 14, second steam generator 16, gas preheater 20, air preheater) provided at the furnace wall, the furnace top, and the furnace bottom of the reforming furnace 17. It is an expanded view which shows the container 21) typically.
　改質炉１７の断熱構造は、改質炉内の燃焼ガスの循環滞留熱損失を防止するために、断熱構造体の外側を鋼板製外板で被覆するとともに、更に、当該鋼板製外板の外側を、断熱性能の高いフレックス材料で被覆して、断熱保温性能を高める構造となっている。そして、炉壁部、炉頂部、炉底部の各外側面に設けられた鋼板製外板には、図４において破線で示されるように、細管コイルの給水ジャケット管が溶着され、第２給水予熱器１４が形成されている。当該構造により、改質炉内の温度が６００℃～１０００℃であるのに対し、鋼板製外板の温度は約２００℃となり、燃焼ガスの熱を有効に回収できる。また、鋼板製外板に給水ジャケット管を溶着して、第２給水予熱器１４を形成したことで、フレックス材料による外部保温を厚くすることなく、十分な保温性能を確保できる。 The heat insulating structure of the reforming furnace 17 covers the outside of the heat insulating structure with a steel plate outer plate in order to prevent the circulation residence heat loss of the combustion gas in the reforming furnace, and further, The outer side is covered with a flex material having high heat insulation performance to increase the heat insulation performance. Then, as shown by the broken line in FIG. 4, a water supply jacket tube of a thin tube coil is welded to the steel plate outer plates provided on the outer surfaces of the furnace wall, the furnace top, and the furnace bottom, and the second water supply preheating is performed. A vessel 14 is formed. With this structure, the temperature in the reforming furnace is 600 ° C. to 1000 ° C., whereas the temperature of the steel plate outer plate is about 200 ° C., and the heat of the combustion gas can be recovered effectively. In addition, since the water supply jacket pipe is welded to the steel plate outer plate to form the second water supply preheater 14, sufficient heat retention performance can be ensured without increasing the external heat retention by the flex material.
　本実施形態では、第１給水予熱器１３で予熱された給水が、炉底部に形成された底部給水ジャケット管の入口に供給される。底部給水ジャケット管の出口は、炉壁部の左右に並列に形成された壁部給水ジャケット管の各入口と接続し、壁部給水ジャケット管の各出口は合流して、炉頂部に形成された頂部給水ジャケット管の入口と接続する。頂部給水ジャケット管の出口を出た予熱された給水は、配管を介して、第２水蒸気発生器１６の入口に供給される。 In the present embodiment, the feed water preheated by the first feed water preheater 13 is supplied to the inlet of the bottom feed jacket tube formed at the bottom of the furnace. The outlet of the bottom water supply jacket tube is connected to each inlet of the wall water jacket tube formed in parallel on the left and right of the furnace wall, and the outlets of the wall water jacket tube merge to form the top of the furnace. Connect to the inlet of the top water jacket tube. The preheated water that has exited the outlet of the top water jacket jacket pipe is supplied to the inlet of the second water vapor generator 16 via a pipe.
　第２水蒸気発生器１６は、炉壁部の上部に横長の開口を設け、当該開口内にコイル配管を設けて形成される廃熱回収ボイラである。上述の給水ジャケット管を通過して予熱された給水が当該コイル配管を通過する際に、高温の燃焼排ガスとの熱交換により加熱され、水蒸気が生成される。第２水蒸気発生器１６のコイル配管の出口は、分岐配管を介して入口配管３６に接続され、第２水蒸気発生器１６で生成された水蒸気と、第１水蒸気発生器１５で生成された水蒸気と、脱硫器１２で脱硫処理された原料ガスとが合流して混合される。 The second steam generator 16 is a waste heat recovery boiler formed by providing a horizontally long opening at the top of the furnace wall and providing a coil pipe in the opening. When the feed water preheated through the above-described feed water jacket pipe passes through the coil pipe, it is heated by heat exchange with the high-temperature combustion exhaust gas, and steam is generated. The outlet of the coil pipe of the second steam generator 16 is connected to the inlet pipe 36 via a branch pipe, and the steam generated by the second steam generator 16 and the steam generated by the first steam generator 15 are The raw material gas desulfurized by the desulfurizer 12 is mixed and mixed.
　水蒸気改質システム１の運転制御において重要なポイントの１つは、ＣＯ変成器２２内の温度を常に安定して維持することであるが、このためには、第１水蒸気発生器１５での蒸気発生量を制御することになり、第１水蒸気発生器１５での蒸気発生量が、ＣＯ変成器２２内の温度に依存して変化することになる。つまり、第１水蒸気発生器１５だけで、改質管１８に供給する水蒸気を賄う場合は、ＣＯ変成器２２内の温度と改質管１８に供給する水蒸気量を同時に最適化するのが困難となる。本実施形態では、これに対処するために、第１給水予熱器１３で予熱された給水を２方向に分岐して、一方を、ＣＯ変成器２２内に形成された第１水蒸気発生器１５に供給し、他方を、燃焼排ガスの廃熱回収用の第２水蒸気発生器１６に供給する構成を採用している。これにより、第１水蒸気発生器１５の蒸気発生量を制御して、ＣＯ変成器２２での発熱を吸収してＣＯ変成反応の温度制御を行い、第２水蒸気発生器１６の蒸気発生量を制御して、改質管１８に供給するプロセス蒸気の発生量の制御を行い、最終的には、バーナ１９の燃焼制御によって安定した運転状態を維持することができる。 One important point in the operation control of the steam reforming system 1 is to keep the temperature in the CO converter 22 stable at all times. For this purpose, steam in the first steam generator 15 is maintained. The generated amount is controlled, and the amount of steam generated in the first steam generator 15 changes depending on the temperature in the CO converter 22. That is, when only the first steam generator 15 covers the steam supplied to the reforming pipe 18, it is difficult to optimize the temperature in the CO converter 22 and the amount of steam supplied to the reforming pipe 18 at the same time. Become. In the present embodiment, in order to cope with this, the feed water preheated by the first feed water preheater 13 is branched in two directions, and one of the feed water is supplied to the first steam generator 15 formed in the CO converter 22. A configuration is adopted in which the other is supplied to the second steam generator 16 for recovering the waste heat of the combustion exhaust gas. Thereby, the steam generation amount of the first steam generator 15 is controlled, the heat generated in the CO converter 22 is absorbed and the temperature of the CO shift reaction is controlled, and the steam generation amount of the second steam generator 16 is controlled. Thus, the generation amount of the process steam supplied to the reforming pipe 18 is controlled, and finally, a stable operation state can be maintained by the combustion control of the burner 19.
　炉壁部の鋼板製外板に溶着された左右一対の壁部給水ジャケット管の間の空間に、第２水蒸気発生器１６を通過した燃焼排ガスの排ガス流路が形成され、当該排ガス流路内に、複数の細管が２組設置され、ガス予熱器２０と空気予熱器２１が形成されている。原料ガスと同じ組成の燃料ガスがガス予熱器２０に供給され、燃焼用空気が、炉壁部の設けられた燃焼用空気ヘッダ３８から取り込まれ、空気予熱器２１に供給される。当該２組の細管を通過する燃料ガスと燃焼用空気は、燃焼排ガスとの熱交換により各別に予熱され、改質炉１７の炉壁部の下端に設けられたバーナ１９に供給される。ガス予熱器２０と空気予熱器２１で熱交換した後の燃焼排ガスは、炉壁部の外側に設けられた煙突３９を介して外部に排出される。 An exhaust gas flow path for the combustion exhaust gas that has passed through the second steam generator 16 is formed in a space between the pair of left and right wall water supply jacket tubes welded to the steel plate outer plate of the furnace wall, In addition, two sets of a plurality of thin tubes are installed, and a gas preheater 20 and an air preheater 21 are formed. A fuel gas having the same composition as the raw material gas is supplied to the gas preheater 20, and combustion air is taken in from the combustion air header 38 provided with the furnace wall and supplied to the air preheater 21. The fuel gas and the combustion air passing through the two sets of narrow tubes are preheated separately by heat exchange with the combustion exhaust gas, and supplied to a burner 19 provided at the lower end of the furnace wall portion of the reforming furnace 17. The combustion exhaust gas after heat exchange between the gas preheater 20 and the air preheater 21 is discharged to the outside through a chimney 39 provided outside the furnace wall.
　以上詳細に説明した改質炉１７の断熱構造と、第２給水予熱器１４、第２水蒸気発生器１６、ガス予熱器２０、及び、空気予熱器２１の構造により、燃焼ガス及び燃焼排ガスの熱を有効に回収でき、熱損失の低減が効果的に図られる。更に、改質炉１７と一体化して構成されたこれらの廃熱回収機器、改質器（改質炉１７、改質管１８）、脱硫器１２、ＣＯ変成器２２、第１給水予熱器１３、及び、第１水蒸気発生器１５等の高温機器を、収容空間１０内において、改質炉１７内、または、その周囲に近接して纏めて配置形成したことで、当該高温機器の外気放熱面積を小さくでき、放熱損失の大幅な低減が図れる。 Due to the heat insulation structure of the reforming furnace 17 described in detail above and the structures of the second feed water preheater 14, the second steam generator 16, the gas preheater 20, and the air preheater 21, the heat of the combustion gas and the combustion exhaust gas is obtained. Can be effectively recovered, and heat loss can be effectively reduced. Furthermore, these waste heat recovery devices, reformers (reforming furnace 17, reforming pipe 18), desulfurizer 12, CO converter 22, and first feed water preheater 13 that are integrated with the reforming furnace 17 are configured. In addition, the high temperature equipment such as the first steam generator 15 is arranged and formed in the housing space 10 in the reforming furnace 17 or in the vicinity thereof so that the outside air heat radiation area of the high temperature equipment can be obtained. The heat dissipation loss can be greatly reduced.
　尚、本実施形態では、円筒状の収容空間１０の外面は、例えば、屋内設置の場合は、耐火クロスで覆われ、屋外設置の場合は、アルミニウム板製または鋼板製の外皮で覆われるが、必ずしも気密性は要しない。 In this embodiment, for example, the outer surface of the cylindrical accommodation space 10 is covered with a fireproof cloth in the case of indoor installation, and is covered with an outer cover made of aluminum plate or steel plate in the case of outdoor installation. Airtightness is not necessarily required.
　次に、図５及び図６を参照して、ＰＳＡ水素分離装置２５の構造及び運転制御方法について説明する。 Next, the structure and operation control method of the PSA hydrogen separator 25 will be described with reference to FIGS.
　本実施形態では、ＰＳＡ水素分離装置２５は、図５に示すように、３槽の吸着槽４０と真空ポンプ４１と補圧ポンプ４２を備える。各吸着槽４０の入口は、夫々、３つの開閉弁を介して、原ガス配管４３、真空ポンプ４１と補圧ポンプ４２の各入口、及び、真空ポンプ４１と補圧ポンプ４２の各出口と、各別に接続している。また、３槽の吸着槽４０の３つの入口は、３組の２つの入口間が相互に開閉弁（均圧弁）を介して接続されている。また、真空ポンプ４１と補圧ポンプ４２の各出口は、開閉弁を介してオフガス配管４２と接続している。各吸着槽４０の出口は、夫々、２つの開閉弁を介して、製品水素ガス配管４５、及び、加圧水素ガス配管４６と、各別に接続している。また、３槽の吸着槽４０の３つの出口は、３組の２つの出口間が相互に開閉弁（均圧弁）を介して接続されている。原ガス配管４３は、ガス冷却器２３のガス出口と、ドレイン分離器２４を介して接続しており、ＣＯ変成器２２で生成され、第１給水予熱器１３及びガス冷却器２３で除熱され、ドレイン分離器２４で水分が除去された変成ガスが、原ガス配管４３に供給される。本実施形態では、補圧ポンプ４２は、真空ポンプを転用しているが、別のガス圧縮機を用いても良い。 In this embodiment, the PSA hydrogen separator 25 includes three adsorption tanks 40, a vacuum pump 41, and a supplementary pump 42 as shown in FIG. The inlets of the adsorption tanks 40 are respectively connected to the raw gas pipe 43, the inlets of the vacuum pump 41 and the auxiliary pressure pump 42, and the outlets of the vacuum pump 41 and the auxiliary pressure pump 42 through three on-off valves. Connected separately. In addition, the three inlets of the three adsorption tanks 40 are connected to each other through two on-off valves (equalizing valves). Further, the outlets of the vacuum pump 41 and the auxiliary pressure pump 42 are connected to the off-gas pipe 42 via an on-off valve. The outlet of each adsorption tank 40 is connected to a product hydrogen gas pipe 45 and a pressurized hydrogen gas pipe 46, respectively, via two on-off valves. The three outlets of the three adsorption tanks 40 are connected to each other between the two sets of two outlets via an on-off valve (pressure equalizing valve). The raw gas pipe 43 is connected to the gas outlet of the gas cooler 23 via the drain separator 24, is generated by the CO converter 22, and is removed by the first feed water preheater 13 and the gas cooler 23. The modified gas from which moisture has been removed by the drain separator 24 is supplied to the raw gas pipe 43. In the present embodiment, the auxiliary pressure pump 42 uses a vacuum pump, but another gas compressor may be used.
　各吸着槽４０の中には、原ガス配管４３に供給される変成ガス中に含まれる、ＣＯ、ＣＯ２、ＣＨ４等の水素以外のガスを吸着する吸着剤が充填されている。本実施形態では、当該吸着剤として、ＣＯ２、ＣＨ４等を物理的に吸着するゼオライト等の物理吸着剤に加えて、ＣＯを化学的に吸着する化学吸着剤を使用している。当該化学吸着剤としては、例えば、神戸製鋼所等が開発した、多孔質アルミナ担体に酸化銅を担持した化学吸着剤がある。化学吸着剤が、物理吸着剤と比較してＣＯに対する吸着能力が高いため、吸着剤の占める容積を低減できるため、オフガス量が少なくなって水素回収率を向上できる。また、オフガス量が減少することで、オフガスに起因する熱損失が低減される。 Each adsorption tank 40 is filled with an adsorbent that adsorbs a gas other than hydrogen, such as CO, CO 2 , and CH 4 , contained in the modified gas supplied to the raw gas pipe 43. In this embodiment, a chemical adsorbent that chemically adsorbs CO is used as the adsorbent in addition to a physical adsorbent such as zeolite that physically adsorbs CO 2 , CH 4 , and the like. As the chemical adsorbent, for example, there is a chemical adsorbent developed by Kobe Steel, etc., in which copper oxide is supported on a porous alumina carrier. Since the chemical adsorbent has a higher adsorption capacity for CO than the physical adsorbent, the volume occupied by the adsorbent can be reduced, so that the amount of off-gas is reduced and the hydrogen recovery rate can be improved. Moreover, the heat loss resulting from offgas is reduced by reducing the amount of offgas.
　次に、図５及び図６を参照して、３槽の吸着槽４０の内の１槽が吸着処理に供される１サイクル中の運転制御について説明する。１サイクルは、第１～第４工程の４工程で構成される。図５では、第１～第４工程における開閉弁の開閉状態が模式的に示されている。図５中、白抜き表示は開状態で、黒塗り表示は閉状態を表している。また、上半分が白抜き、下半分が黒塗り表示は、第３工程で開状態、第４工程で閉状態であることを示し、上半分が黒塗り、下半分が白抜き表示は、第３工程で閉状態、第４工程で開状態であることを示している。 Next, with reference to FIG. 5 and FIG. 6, operation control during one cycle in which one of the three adsorption tanks 40 is subjected to adsorption treatment will be described. One cycle is composed of four steps of the first to fourth steps. FIG. 5 schematically shows the open / close state of the on-off valve in the first to fourth steps. In FIG. 5, the white display indicates the open state, and the black display indicates the closed state. In addition, the upper half is outlined white and the lower half is black, indicating that it is open in the third step and closed in the fourth step. The upper half is black and the lower half is white. The closed state is shown in 3 steps, and the open state is shown in the 4th step.
　以下では、３槽の吸着槽４０の内の１槽目が吸着処理に供され、２層目が前サイクルで吸着処理に供され、３層目は次サイクルで吸着処理に供される場合の現サイクルでの制御について説明する。 In the following, the first of the three tanks 40 is subjected to the adsorption process, the second layer is subjected to the adsorption process in the previous cycle, and the third layer is subjected to the adsorption process in the next cycle. The control in the current cycle will be described.
　先ず、図５に示すように、第１～第４工程を通して、１層目の吸着槽４０の入口と原ガス配管４３の間の開閉弁と、１層目の吸着槽４０の出口と製品水素ガス配管４５の間の開閉弁が開状態となり、１層目の吸着槽４０が高圧状態に維持されて吸着処理に供され、１層目の吸着槽４０で水素以外のガスが吸着除去され生成された製品水素ガスが、製品水素ガス配管４５に送出される。 First, as shown in FIG. 5, through the first to fourth steps, an on-off valve between the inlet of the first layer adsorption tank 40 and the raw gas pipe 43, the outlet of the first layer adsorption tank 40, and product hydrogen. The on-off valve between the gas pipes 45 is opened, the first layer adsorption tank 40 is maintained in a high pressure state and subjected to adsorption treatment, and gas other than hydrogen is adsorbed and removed in the first layer adsorption tank 40 and generated. The produced product hydrogen gas is sent to the product hydrogen gas pipe 45.
　第１工程で、図５に示すように、２層目と３層目の吸着槽４０の槽内圧を均等化するために、当該２つの吸着槽４０の入口間の開閉弁と出口間の開閉弁を夫々開いて、２層目と３層目の吸着槽４０間を連通させ、３槽目の吸着槽４０内を昇圧し、２槽目の吸着槽４０内を減圧する（均圧処理）。 In the first step, as shown in FIG. 5, in order to equalize the tank internal pressure of the second and third adsorption tanks 40, the opening / closing valve between the inlets of the two adsorption tanks 40 and the opening / closing between the outlets. Each valve is opened to allow the second and third adsorption tanks 40 to communicate with each other, the pressure in the third adsorption tank 40 is increased, and the pressure in the second adsorption tank 40 is reduced (equal pressure treatment). .
　第２工程で、図５に示すように、２層目と３層目の吸着槽４０の入口間の開閉弁と出口間の開閉弁を閉じ、２層目の吸着槽４０の入口と捕圧ポンプ４０の入口の間の開閉弁と、３層目の吸着槽４０の入口と捕圧ポンプ４０の出口の間の開閉弁を夫々開いて、２層目と３層目の吸着槽４０間を、捕圧ポンプ４０を介して連通させ、２槽目の吸着槽４０内の残留ガスを捕圧ポンプ４０で圧縮して３槽目の吸着槽４０内に送出し、３槽目の吸着槽４０内を更に昇圧し、２槽目の吸着槽４０内を更に減圧する（補圧処理）。 In the second step, as shown in FIG. 5, the on-off valve between the inlets of the second layer and the third layer adsorption tank 40 and the on-off valve between the outlets are closed, and the inlet of the second layer adsorption tank 40 and the trapping pressure are closed. An on-off valve between the inlets of the pump 40 and an on-off valve between the inlet of the third layer adsorption tank 40 and the outlet of the pressure pump 40 are opened, and the gap between the second layer and the third layer adsorption tank 40 is opened. The residual gas in the second adsorption tank 40 is compressed by the pressure pump 40 and is sent into the third adsorption tank 40 to be communicated via the pressure pump 40, and the third adsorption tank 40. The inside is further pressurized, and the inside of the second adsorption tank 40 is further depressurized (complementary pressure treatment).
　第３工程で、３層目の吸着槽４０の入口と捕圧ポンプ４０の出口の間の開閉弁を閉じて、３層目の吸着槽４０の出口と加圧水素ガス配管４６の間の開閉弁と、２層目の吸着槽４０の入口と真空ポンプ４１の入口の間の開閉弁と、真空ポンプ４１の出口とオフガス配管４４の間の開閉弁を夫々開いて、製品水素ガスの一部を加圧した加圧水素を加圧水素ガス配管４６から３層目の吸着槽４０内に送入して加圧し、次サイクルの吸着処理に備え、２層目の吸着槽４０から真空ポンプ４１により真空脱着したオフガス（水素以外のガス）を、オフガス配管４４に送出して、燃料ガス貯槽に回収する。 In the third step, the on-off valve between the inlet of the third layer adsorption tank 40 and the outlet of the pressure pump 40 is closed, and the on-off valve between the outlet of the third layer adsorption tank 40 and the pressurized hydrogen gas pipe 46 is closed. And opening an on-off valve between the inlet of the second layer adsorption tank 40 and the inlet of the vacuum pump 41 and an on-off valve between the outlet of the vacuum pump 41 and the off-gas pipe 44 respectively, Pressurized pressurized hydrogen is fed into the third layer adsorption tank 40 from the pressurized hydrogen gas pipe 46 and pressurized, and vacuum desorption is performed from the second layer adsorption tank 40 by the vacuum pump 41 in preparation for the adsorption process of the next cycle. The off gas (gas other than hydrogen) is sent to the off gas pipe 44 and collected in the fuel gas storage tank.
　第４工程で、３層目の吸着槽４０の出口と加圧水素ガス配管４６の間の開閉弁を閉じて、３層目の吸着槽４０に対する水素加圧を停止し、第３工程に引き続き、２層目の吸着槽４０の入口と真空ポンプ４１の入口の間の開閉弁と、真空ポンプ４１の出口とオフガス配管４４の間の開閉弁を夫々開いた状態とし、２層目の吸着槽４０の出口と加圧水素ガス配管４６の間の開閉弁を開き、２層目の吸着槽４０に対して、製品水素ガスの一部を用いて、吸着剤の洗浄と残留ガスのパージ処理を行う。 In the fourth step, the on-off valve between the outlet of the third layer adsorption tank 40 and the pressurized hydrogen gas pipe 46 is closed to stop the hydrogen pressurization to the third layer adsorption tank 40. The on / off valve between the inlet of the second layer adsorption tank 40 and the inlet of the vacuum pump 41 and the on / off valve between the outlet of the vacuum pump 41 and the off-gas pipe 44 are opened, respectively. The on-off valve between the outlet of the gas and the pressurized hydrogen gas pipe 46 is opened, and the adsorbent is cleaned and the residual gas is purged with respect to the second-layer adsorption tank 40 using a part of the product hydrogen gas.
　以上の第１～第４工程の１サイクル中の各制御を、吸着処理に供される１層の吸着槽４０を循環的に変更しながら全サイクルが完了する。本実施形態では、第２工程の補圧処理と第３工程の真空脱着処理を経てパージを行うことで、従来のＰＳＡ水素分離において脱着及びパージに使用されていた水素量を大幅に削減でき、水素回収率の向上が図れる。 All the controls in one cycle of the above first to fourth steps are completed while cyclically changing the single-layer adsorption tank 40 used for the adsorption treatment. In the present embodiment, the amount of hydrogen used for desorption and purging in the conventional PSA hydrogen separation can be greatly reduced by performing the purging through the pressure compensation process in the second step and the vacuum desorption process in the third step. The hydrogen recovery rate can be improved.
　尚、第１工程の均圧処理用に、各吸着槽４０の入口側と出口側の両方に均圧弁（開閉弁）を設けている。これは、均圧時間を短縮するとともに、急激なガス流に対し、吸着槽４０内の状態の変化を防止するためであるが、均圧弁を各吸着槽４０の入口側と出口側の一方側にのみ設けても、均圧処理は実施可能である。 For the pressure equalization process in the first step, pressure equalization valves (open / close valves) are provided on both the inlet side and the outlet side of each adsorption tank 40. This is for shortening the pressure equalization time and preventing a change in the state in the adsorption tank 40 against an abrupt gas flow, but the pressure equalization valve is provided on one side of the inlet side and the outlet side of each adsorption tank 40. Even if it is provided only in the case, the pressure equalization process can be carried out.
　次に、図１を参照して、水蒸気改質システム１を用いた製品水素が製造されるまでのプロセスを説明する。ここで、原料ガスとして、メタンを主成分とする都市ガス（１３Ａガス）の使用を想定する。 Next, with reference to FIG. 1, a process until product hydrogen is produced using the steam reforming system 1 will be described. Here, use of city gas (13A gas) which has methane as a main component is assumed as source gas.
　原料ガスは、製品水素ガスから分流された脱硫用水素ガスが混入され、原料圧縮機１１で、約０．９ＭＰａに圧縮された後、ＣＯ変成器２２の外周にある脱硫器１２に入る。ここで、ＣＯ変成器２２からの熱伝導により加熱された超高次脱硫触媒により吸着脱硫される。脱硫された原料ガスは、ＣＯ変成器２２内の第１水蒸気発生器１５で発生した水蒸気と、第２水蒸気発生器１６で発生した水蒸気と混合され、改質炉１７内の改質管１８に入り水蒸気改質される。改質管１８内の外側流路３０の入口付近の原料ガス温度は、約２００～２５０℃で、外側流路３０を通過して水蒸気改質された改質ガスの改質管１８の下端部での温度は、約８２０～８７０℃で、内側流路３１を除熱されながら通過した後の改質管１８の出口での改質ガス温度は、約４００～４５０℃となってＣＯ変成器２２に入る。ＣＯ変成器２２に入った改質ガスは、発熱反応のＣＯ変成反応が行われるが、変成触媒中に形成された第１水蒸気発生器１５のコイル配管との間の熱交換によって冷却され、最終温度が約２００℃となって、十分に変成された変成ガスになる。 The raw material gas is mixed with desulfurized hydrogen gas separated from the product hydrogen gas, compressed to about 0.9 MPa by the raw material compressor 11, and then enters the desulfurizer 12 on the outer periphery of the CO converter 22. Here, adsorptive desulfurization is performed by an ultrahigh-order desulfurization catalyst heated by heat conduction from the CO converter 22. The desulfurized raw material gas is mixed with the water vapor generated by the first water vapor generator 15 in the CO converter 22 and the water vapor generated by the second water vapor generator 16, and is mixed into the reforming pipe 18 in the reforming furnace 17. Steam reforming is performed. The temperature of the raw material gas in the vicinity of the inlet of the outer flow path 30 in the reforming pipe 18 is about 200 to 250 ° C., and the lower end portion of the reforming pipe 18 of the reformed gas steam-reformed through the outer flow path 30. Is about 820 to 870 ° C., and the reformed gas temperature at the outlet of the reforming pipe 18 after passing through the inner flow path 31 is about 400 to 450 ° C. Enter 22. The reformed gas that has entered the CO converter 22 undergoes an exothermic CO conversion reaction, but is cooled by heat exchange with the coil piping of the first steam generator 15 formed in the conversion catalyst. The temperature becomes about 200 ° C., and the transformed gas is fully transformed.
　また、ＣＯ変成反応中の被処理ガスはＣＯ変成器２２の外壁を通じて外槽部の脱硫触媒を加熱しながら除熱される。ＣＯ変成器２２を出た変成ガスは第１給水予熱器１３に入り高度に熱回収される。熱回収された変成ガスはガス冷却器２３に入り、後段のドレイン分離器２４で、ドレインが分離除去された後、ＰＳＡ水素分離装置２５に入り、製品水素ガスとオフガスに分離される。このオフガスは、原料ガスと同じ１３Ａ都市ガスの燃料ガスと混合されてバーナ１９の燃料となり、燃焼用空気によって燃焼され、改質炉１７内において改質管１８を加熱する。燃焼排ガスは、その廃熱により第２水蒸気発生器１６で水蒸気を発生させ、更に、燃焼用空気と燃料ガスと夫々熱交換し、約１００℃となって煙突から排出される。 In addition, the gas to be treated during the CO shift reaction is removed by heating the desulfurization catalyst in the outer tank portion through the outer wall of the CO shift converter 22. The modified gas exiting the CO converter 22 enters the first feed water preheater 13 and is highly recovered. The heat-recovered metamorphic gas enters the gas cooler 23, and the drain is separated and removed by the subsequent drain separator 24, and then enters the PSA hydrogen separator 25 and separated into product hydrogen gas and off-gas. This off-gas is mixed with the fuel gas of 13A city gas, which is the same as the raw material gas, to become the fuel for the burner 19, burned by the combustion air, and heats the reforming pipe 18 in the reforming furnace 17. The combustion exhaust gas generates steam by the second steam generator 16 due to its waste heat, and further exchanges heat between the combustion air and the fuel gas, and is discharged from the chimney at about 100 ° C.
　次に、図７を参照して、本実施形態に係る水蒸気改質システム１の運転成績をシミュレーションにて予想した結果を説明する。 Next, with reference to FIG. 7, the result of having predicted the operation result of the steam reforming system 1 which concerns on this embodiment by simulation is demonstrated.
　各ケース＃１～＃８とも、改質炉の負荷がほぼ同じとなる条件で、原料消費量とＳ／Ｃを変更し、熱発生に対する全放熱損失の割合を６％（装置外表面積当たり、約５００Ｗ／ｍ２）、燃焼空気比を１．０５として、シミュレーションによって運転成績を求めた。尚、図７中の改質ガス組成比は、ドライ表示である。また、エネルギ効率の計算では、図８に示すシミュレーションも含め、電力の原単位を９ＭＪ／ｋＷｈ（発電効率４０％ＨＨＶ）とした。 In each case # 1 to # 8, the raw material consumption and S / C were changed under the condition that the load of the reforming furnace was almost the same, and the ratio of the total heat loss to heat generation was 6% (per unit surface area, About 500 W / m 2 ), the combustion air ratio was set to 1.05, and the operation results were obtained by simulation. In addition, the reformed gas composition ratio in FIG. 7 is a dry display. Further, in the calculation of energy efficiency, the basic unit of electric power was 9 MJ / kWh (power generation efficiency 40% HHV) including the simulation shown in FIG.
　その結果、全てのケースにおいて目標である水素ガス化効率９０％を達成している。図７において、原料ガスが１３Ａ都市ガスのケース＃１～＃３の比較では、Ｓ／Ｃに対する原料消費量と燃料消費量の合計当たりの水素ガス製造量、水素ガス化効率、エネルギ効率の全てにおいて、Ｓ／Ｃが小さいほど優れた値を示しているが、Ｓ／Ｃが１．８以下では殆ど差がなく、１．７以下になると、オフガス発生量が過剰になって、全ての成績が低下することになる。また、Ｓ／Ｃが小さくなると、改質ガス中のＣＯ濃度が上昇する傾向が見られる。 As a result, the target hydrogen gasification efficiency of 90% has been achieved in all cases. In FIG. 7, the comparison of Cases # 1 to # 3 where the source gas is 13A city gas shows that all of the hydrogen gas production amount, hydrogen gasification efficiency, and energy efficiency per the total of the raw material consumption and the fuel consumption with respect to S / C However, when S / C is 1.8 or less, there is almost no difference, and when S / C is 1.7 or less, the off-gas generation amount becomes excessive, and all results are shown. Will drop. Moreover, when S / C becomes small, the tendency for CO concentration in reformed gas to rise is seen.
　ケース＃５は、他のケース及び上記実施形態とは異なり、ＣＯ吸着剤に化学吸着剤ではなく、従来のゼオライトを用いた。ケース＃５の水素回収率は、８２．９７％と低いが、水素ガス化効率は９０．６９％と９０％以上を達成している。しかし，水素ガス製造量はケース＃４と比較して約９１％に低下している。 Case # 5 used a conventional zeolite instead of a chemical adsorbent as the CO adsorbent, unlike the other cases and the above embodiment. The hydrogen recovery rate of Case # 5 is as low as 82.97%, but the hydrogen gasification efficiency is 90.69%, which is 90% or more. However, the hydrogen gas production volume is reduced to about 91% compared to Case # 4.
　原料ガスがブタンのケース＃６～＃８でも、水素ガス化効率及び水素製造量に対するＳ／Ｃの影響は、ケース＃１～＃４と同様の傾向を示しているが、Ｓ／Ｃの最適値は、原料ガスが１３Ａ都市ガスの場合よりも若干高くなる。 Even in case # 6 to # 8 where the source gas is butane, the effect of S / C on hydrogen gasification efficiency and hydrogen production shows the same trend as in cases # 1 to # 4, but the optimum S / C The value is slightly higher than when the source gas is 13A city gas.
　尚、図７において、原料ガスが１３Ａ都市ガスの場合、水素ガス化効率に対するエネルギ効率の差は大きいが、改質に必要な圧力まで原料圧縮機で圧縮する動力に対し、原料ガスがブタンの場合は、ポンプで昇圧するため動力が小さく、この部分を除外すれば、水素ガス化効率とエネルギ効率の差は殆ど無いと言える。 In FIG. 7, when the raw material gas is 13A city gas, the difference in energy efficiency with respect to the hydrogen gasification efficiency is large, but the raw material gas is butane compared to the power compressed by the raw material compressor up to the pressure required for reforming. In this case, the power is small because the pressure is increased by the pump, and if this portion is excluded, it can be said that there is almost no difference between the hydrogen gasification efficiency and the energy efficiency.
　次に、図８及び図９を参照して、本実施形態に係る水蒸気改質システム１、及び、既存の製品化されている水蒸気改質システムの運転成績をシミュレーションにて予想し対比した結果を説明する。図８は、本発明に係る水蒸気改質システムの条件別の予想運転成績と既存の製品化されている水蒸気改質システムの予想運転成績を比較した一覧表であり、図９は、図８に示す条件別の予想運転成績における放熱損失、Ｐ流体冷却損失、燃焼排ガス損失、及び、水素ガス化効率の構成比率を示す棒グラフである。 Next, referring to FIG. 8 and FIG. 9, the results of predicting and comparing the operation results of the steam reforming system 1 according to the present embodiment and the steam reforming system that has already been commercialized by simulation are shown. explain. FIG. 8 is a table comparing the predicted operation results for each condition of the steam reforming system according to the present invention and the predicted operation results of the existing steam reforming system, and FIG. It is a bar graph which shows the composition ratio of the heat dissipation loss, P fluid cooling loss, combustion exhaust gas loss, and hydrogen gasification efficiency in the prediction operation result according to the conditions to show.
　各ケース＃１１～＃１９とも、改質炉の負荷がほぼ同じとなる条件で、原料消費量とＳ／Ｃを変更し、熱発生に対する全放熱損失の割合を６％（ケース＃１１～＃１３）、２０％（ケース＃１４～＃１８）、２２．４５％（ケース＃１９）とし、燃焼空気比を１．０５（ケース＃１１～＃１５）、１．２０（ケース＃１６～＃１９）として、シミュレーションによって運転成績を求めた。尚、図８中の変成ガス組成比は、ウェット表示である。 In each case # 11 to # 19, the raw material consumption and S / C are changed under the condition that the load of the reforming furnace is almost the same, and the ratio of the total heat dissipation loss to the heat generation is 6% (cases # 11 to # 19). 13), 20% (cases # 14 to # 18), 22.45% (case # 19), and the combustion air ratio is 1.05 (cases # 11 to # 15) and 1.20 (cases # 16 to ##). As 19), driving results were obtained by simulation. The modified gas composition ratio in FIG. 8 is wet display.
　ケース＃１４～＃１８では、高温機器を、上記実施形態で示したように円筒状の収容空間内にコンパクトに収容せず、図１０に例示したように、個々に箱型の筐体内に設置された場合を想定し、熱発生に対する全放熱損失の割合を２０％に増加している。ケース＃１９は、既存の水素製造能力１００ｍ３Ｎ／ｈの水素製造装置の仕様を参考にしたものである。 In cases # 14 to # 18, the high-temperature equipment is not housed compactly in the cylindrical housing space as shown in the above embodiment, but is individually installed in a box-shaped housing as illustrated in FIG. The ratio of the total heat dissipation loss to the heat generation is increased to 20%. Case # 19 refers to the specifications of an existing hydrogen production apparatus with a hydrogen production capacity of 100 m 3 N / h.
　ケース＃１１～＃１３は、図７に示すケース＃１～＃４と同様に、水素ガス化効率９０％を概ね達成している。ケース＃１３では、Ｓ／Ｃが２．４と、ケース＃１～＃４のＳ／Ｃの０．７～２．２より大きいため、水素ガス化効率は８９．５３％と僅かに９０％を下回っているが、小数点以下を四捨五入すると９０％となる。従って、Ｓ／Ｃを１．７以上２．４以下、好ましくは、１．８以上２．３以下に設定できるのは好ましい。Ｓ／Ｃを調整する際には、原料ガス及び水蒸気の供給量を同時に制御する、或いは、原料ガスの供給量を固定し水蒸気の供給量を制御する、或いは、水蒸気量供給量を固定し、原料ガスの供給量を制御することに行う。 Cases # 11 to # 13 generally achieve a hydrogen gasification efficiency of 90%, as in cases # 1 to # 4 shown in FIG. In case # 13, the S / C is 2.4, which is larger than 0.7-2.2 of S / C in cases # 1 to # 4, so the hydrogen gasification efficiency is 89.53%, which is only 90%. Is rounded down to the nearest 90%. Therefore, it is preferable that S / C can be set to 1.7 or more and 2.4 or less, and preferably 1.8 or more and 2.3 or less. When adjusting the S / C, simultaneously control the supply amount of the raw material gas and water vapor, or control the supply amount of water vapor by fixing the supply amount of the raw material gas, or fix the supply amount of water vapor, This is done by controlling the supply amount of the source gas.
　ケース＃１３と＃１４を対比すると、熱発生に対する全放熱損失の割合を６％から２０％に悪化させると、水素ガス化効率８９．５３％から８４．６８％へと、約５％低下する。しかし、ケース＃１９の既存の水蒸気改質システムの水素ガス化効率６８．２５％と比べると、約１６％高い。また、ケース＃１４～＃１８を比較すると、熱発生に対する全放熱損失の割合が２０％では、燃焼条件等を色々変化させても、水素ガス化効率が８５％以上にならないことが分かる、しかし、Ｓ／Ｃを２．４に設定できれば、８５％以上ではないが、８０％を超える水素ガス化効率は実現できることが分かる。以上より、熱発生に対する全放熱損失の割合を６％となるように、熱損失を低減し、Ｓ／Ｃを１．７以上２．４以下、好ましくは、１．８以上２．３以下に設定することで、水素ガス化効率９０％を達成できることが分かる。 Comparing cases # 13 and # 14, if the ratio of the total heat dissipation loss to heat generation is reduced from 6% to 20%, the hydrogen gasification efficiency is reduced by about 5% from 89.53% to 84.68%. . However, it is about 16% higher than the hydrogen gasification efficiency 68.25% of the existing steam reforming system in Case # 19. Further, comparing cases # 14 to # 18, it can be seen that when the ratio of the total heat dissipation loss to heat generation is 20%, the hydrogen gasification efficiency does not exceed 85% even if various combustion conditions are changed. It can be seen that if the S / C can be set to 2.4, the hydrogen gasification efficiency exceeding 80% can be realized, although not 85% or more. From the above, the heat loss is reduced so that the ratio of the total heat dissipation loss to the heat generation is 6%, and the S / C is 1.7 or more and 2.4 or less, preferably 1.8 or more and 2.3 or less. It turns out that 90% of hydrogen gasification efficiency can be achieved by setting.
　以下に、本実施形態に係る水蒸気改質システム１の他の実施態様につき説明する。 Hereinafter, another embodiment of the steam reforming system 1 according to this embodiment will be described.
　〈１〉上記実施形態では、ＣＯ変成器２２で生成された変成ガスに対して、水素以外のガスを除去して、水素を分離するために、ＰＳＡ水素分離装置２５を使用したが、ＰＳＡ水素分離装置２５に代えて、例えば、ＣＯを選択酸化除去するＣＯ選択酸化除去器を備え、ＣＯ２を膜分離法等で分離除去するようにしても良い。また、ＰＳＡ水素分離装置２５の前段に、ＣＯ選択酸化除去器やＣＯ２膜分離装置等を設けることで、ＰＳＡ水素分離装置２５の規模を縮小することができる。 <1> In the above embodiment, the PSA hydrogen separator 25 is used to remove hydrogen other than hydrogen and separate hydrogen from the shift gas generated by the CO converter 22. Instead of the separation device 25, for example, a CO selective oxidation remover that selectively removes CO may be provided, and CO 2 may be separated and removed by a membrane separation method or the like. Moreover, the scale of the PSA hydrogen separation device 25 can be reduced by providing a CO selective oxidation remover, a CO 2 membrane separation device, or the like before the PSA hydrogen separation device 25.
　〈２〉上記実施形態では、ＰＳＡ水素分離装置２５として、３槽式のＰＳＡ水素分離装置を用いて、補圧処理を行う場合を想定したが、当該補圧処理に代えて、例えば、４層式のＰＳＡ水素分離装置を用いて、均圧処理を２回行うようにしても良い。また、ＰＳＡ水素分離装置２５は、３槽式または４槽式に限定されるものではなく、また、運転制御の方式も、上記実施形態の制御方法に限定されるものではない。 <2> In the above embodiment, it is assumed that the PSA hydrogen separation device 25 uses a three-tank PSA hydrogen separation device to perform the pressure compensation process, but instead of the pressure compensation process, for example, four layers The pressure equalizing process may be performed twice using a PSA hydrogen separator of the type. Further, the PSA hydrogen separation device 25 is not limited to the three-tank type or the four-tank type, and the operation control method is not limited to the control method of the above embodiment.
　〈３〉上記実施形態では、第１水蒸気発生器１５と第２水蒸気発生器１６を並列的に設けたが、例えば、ＣＯ変成器２２と脱硫器１２の間の熱交換量を調整すること、或いは、第２給水予熱器１４を通過した給水を第１水蒸気発生器１５に供給すること等で、第１水蒸気発生器１５の水蒸気発生量を、ＣＯ変成反応の温度制御とともに適正化できる場合では、必ずしも第２水蒸気発生器１６を設けなくても良い。 <3> In the above embodiment, the first steam generator 15 and the second steam generator 16 are provided in parallel. For example, adjusting the amount of heat exchange between the CO converter 22 and the desulfurizer 12; Alternatively, in the case where the amount of water vapor generated by the first water vapor generator 15 can be optimized together with the temperature control of the CO shift reaction by supplying the first water vapor generator 15 with the feed water that has passed through the second water feed preheater 14. However, the second water vapor generator 16 is not necessarily provided.
　〈４〉上記実施形態では、改質炉１７から排出される燃焼排ガスの廃熱を回収するために、第２給水予熱器１４、第１水蒸気発生器１５、ガス予熱器２０、空気予熱器２１を、改質炉１７の断熱構造体に近接して形成したが、当該廃熱回収機器の具体的な構成例は、図４に例示した構成に限定されるものではない。また、上記実施形態では、第１給水予熱器１３を通過した給水を第２給水予熱器１４に供給する構成としたが、第１給水予熱器１３を通過した給水を第１水蒸気発生器１５にのみ供給し、第２給水予熱器１４には、第１給水予熱器１３に供給するのと同じ温度の給水を供給する構成としても良い。 <4> In the above embodiment, in order to recover the waste heat of the combustion exhaust gas discharged from the reforming furnace 17, the second feed water preheater 14, the first steam generator 15, the gas preheater 20, and the air preheater 21 are collected. However, the specific configuration example of the waste heat recovery apparatus is not limited to the configuration illustrated in FIG. 4. In the above embodiment, the feed water that has passed through the first feed water preheater 13 is supplied to the second feed water preheater 14. However, the feed water that has passed through the first feed water preheater 13 is supplied to the first steam generator 15. Alternatively, the second feed water preheater 14 may be configured to supply feed water having the same temperature as that supplied to the first feed water preheater 13.
　〈５〉上記実施形態では、改質炉１７の上面視形状（外形）を、図２（Ａ）に示すような円形の外周部の一部を切り欠いた形状とし、改質炉１７の内部空間の上面視形状が、略“Ｃ”形としたが、改質炉１７の外形及び内部空間の上面視形状は、図２に例示したものに限定されるものではない。例えば、改質炉１７の上面視形状（外形）を、完全なドーナツ形状として、改質炉１７の内部空間を環状に形成しても良い、この場合、脱硫器１２、ＣＯ変成器２２、及び、第１水蒸気発生器１５等を収容する余剰スペースを、収容空間１０の中心に設け、その全周を、改質炉１７が囲む構成としても良い。また、改質管１８の本数も、図１に例示した５本に限定されるものではなく、改質炉１７の内部空間の形状及び大きさに応じて適宜変更可能である。また、収容空間１０の上面視形状も円形に限定されるものではなく、例えば、楕円形、角が丸くなった矩形等でも良い。また、改質炉１７の上面視の外形も、収容空間１０の上面視形状に合わせて変形させても良い。 <5> In the above embodiment, the top view shape (outer shape) of the reforming furnace 17 is a shape in which a part of a circular outer peripheral portion as shown in FIG. The top view shape of the space is substantially “C” shape, but the outer shape of the reforming furnace 17 and the top view shape of the internal space are not limited to those illustrated in FIG. 2. For example, the top view shape (outer shape) of the reforming furnace 17 may be a complete donut shape, and the inner space of the reforming furnace 17 may be formed in an annular shape. In this case, the desulfurizer 12, the CO converter 22, and A surplus space for housing the first steam generator 15 and the like may be provided in the center of the housing space 10 and the entire circumference thereof may be surrounded by the reforming furnace 17. Further, the number of the reforming pipes 18 is not limited to the five illustrated in FIG. 1 and can be appropriately changed according to the shape and size of the internal space of the reforming furnace 17. Further, the top view shape of the accommodation space 10 is not limited to a circle, and may be, for example, an ellipse or a rectangle with rounded corners. Further, the outer shape of the reforming furnace 17 as viewed from above may be changed in accordance with the shape of the accommodation space 10 as viewed from above.
　また、改質管１７の形状及び寸法も、２重管構造である限りにおいて、上記実施形態で説明した内容に限定されるものではない。例えば、逆ボトル型ではなく、外管２６と内管２７の何れも、または、何れか一方が、中央部分で拡径しない直管であっても良い、例えば、外管２６と内管２７がともに直管であっても、外側流路３０内に伝導する単位伝熱面積当たりの伝熱量（熱流束）は、上側ほど少なくなり、外側流路３０の上端部分では、被処理ガスの温度上昇が緩やかなものになるという効果は奏し得る。更に、改質管１７の外管２６と内管２７の端部の遮閉構造及び形状も、上記実施形態で説明した内容に限定されるものではない。 Further, the shape and dimensions of the reforming tube 17 are not limited to the contents described in the above embodiment as long as the reforming tube 17 has a double tube structure. For example, instead of the reverse bottle type, either the outer pipe 26 or the inner pipe 27 or either one of them may be a straight pipe whose diameter is not expanded at the center portion. For example, the outer pipe 26 and the inner pipe 27 Even if both are straight pipes, the heat transfer amount (heat flux) per unit heat transfer area conducted in the outer flow path 30 decreases toward the upper side, and the temperature of the gas to be processed increases at the upper end portion of the outer flow path 30. The effect of becoming moderate can be achieved. Further, the blocking structure and shape of the end portions of the outer tube 26 and the inner tube 27 of the reforming tube 17 are not limited to the contents described in the above embodiment.
　また、上記実施形態では、改質管１８の上側に入口管３２と出口管３３を設けた構成としたが、改質管１８の上下を反転して、入口管３２と出口管３３を改質管１８の下側に配して、改質管１８から入った原料ガスと水蒸気の混合ガスが、外部流路３０を上向きに通過するようにしても良い。但し、この場合、バーナ１９は、炉壁の下端部や改質炉１７内の炉底部ではなく、炉壁の上端部や改質炉１７内の炉頂部に設置する。 In the above embodiment, the inlet pipe 32 and the outlet pipe 33 are provided on the upper side of the reforming pipe 18. However, the upper and lower sides of the reforming pipe 18 are inverted to reform the inlet pipe 32 and the outlet pipe 33. A gas mixture of raw material gas and water vapor that has entered from the reforming pipe 18 may be disposed below the pipe 18 so as to pass upward through the external flow path 30. However, in this case, the burner 19 is installed not on the lower end of the furnace wall or the bottom of the furnace in the reforming furnace 17 but on the upper end of the furnace wall or the top of the furnace in the reforming furnace 17.
　〈６〉上記実施形態では、脱硫器１２とＣＯ変成器２２は、同心円筒容器の外槽部に脱硫器１２を形成し、内槽部にＣＯ変成器２２を形成したが、内外を反転させて、内槽部に脱硫器１２を形成し、外槽部にＣＯ変成器２２を形成しても良い。更に、原料ガス中に硫黄化合物が含まれない場合は、必ずしも脱硫器１２を設けなくても良い、しかし、脱硫器１２の有無に拘わらず、原料ガス中に少量の水素を添加して、カーボン発生を抑制するのが好ましい。 <6> In the above embodiment, the desulfurizer 12 and the CO converter 22 are formed in the outer tank portion of the concentric cylindrical container and the CO converter 22 is formed in the inner tank portion. The desulfurizer 12 may be formed in the inner tank portion, and the CO transformer 22 may be formed in the outer tank portion. Further, when the source gas does not contain a sulfur compound, the desulfurizer 12 is not necessarily provided. However, regardless of the presence or absence of the desulfurizer 12, a small amount of hydrogen is added to the source gas, It is preferable to suppress the occurrence.
　〈７〉次に、本実施形態に係る水蒸気改質システム１を備えた発電システムについて簡単に説明する。本発電システムは、本実施形態に係る水蒸気改質システム１と、水素製造システム１が生成する水素を消費して発電する発電装置を備えて構成され、水蒸気改質システム１の水素ガス化効率が９０％以上の場合を想定する。 <7> Next, a power generation system including the steam reforming system 1 according to the present embodiment will be briefly described. This power generation system includes a steam reforming system 1 according to this embodiment and a power generation device that consumes hydrogen generated by the hydrogen production system 1 to generate power, and the hydrogen gasification efficiency of the steam reforming system 1 is high. A case of 90% or more is assumed.
　例えば、発電装置として、近年発電効率が５０％以上に向上した固体高分子形燃料電池（ＰＥＦＣ）等を採用することで、発電システム全体として、極めて高い発電効率が得られる。例えば、発電装置の発電効率が５０％と仮定し、水素製造システムの水素ガス化効率が９０％として直交変換効率や自家消費電力を考慮すると、その送電端効率（ＨＨＶ）は４４％程度になり、天然ガスのガスタービンコンバインドサイクル（ＧＴＣＣ）発電に匹敵する発電効率となる。 For example, by using a polymer electrolyte fuel cell (PEFC) or the like whose power generation efficiency has been improved to 50% or more in recent years as a power generation device, extremely high power generation efficiency can be obtained as a whole power generation system. For example, assuming that the power generation efficiency of the power generation device is 50% and the hydrogen gasification efficiency of the hydrogen production system is 90%, considering the orthogonal transformation efficiency and private power consumption, the power transmission end efficiency (HHV) is about 44%. The power generation efficiency is comparable to natural gas gas turbine combined cycle (GTCC) power generation.
　更に、本発電システムは、燃料電池自動車（ＦＣＶ）等の水素を燃料とする車両用の水素供給基地（サテライト水素供給基地）にも、好適に採用し得る。例えば、発電装置が、上記水素供給基地内に設けられた、電気自動車に電力を供給する電力供給設備を構成すると、発電装置の発電電力を、電気自動車に向けに供給することで、高い稼働率が実現できる。また、当該発電電力は、水素の圧縮電力にも利用でき、外販も可能である。 Furthermore, this power generation system can also be suitably used for a hydrogen supply base (satellite hydrogen supply base) for vehicles that use hydrogen as fuel, such as fuel cell vehicles (FCV). For example, when the power generation device constitutes a power supply facility for supplying electric power to an electric vehicle provided in the hydrogen supply base, a high operating rate can be obtained by supplying the electric power generated by the power generation device toward the electric vehicle. Can be realized. In addition, the generated power can be used for compressed hydrogen power and can be sold externally.
　本発明は、燃料電池や金属処理の用に供される水素を、炭化水素系ガスを改質することで製造する水蒸気改質システム、及び、当該水蒸気改質システムを備えて構成される発電システムに利用可能であり、特に、燃料電池自動車（ＦＣＶ）用のサテライト水素供給基地に有用である。 The present invention relates to a steam reforming system for producing hydrogen used for fuel cells and metal processing by reforming a hydrocarbon-based gas, and a power generation system including the steam reforming system. And is particularly useful for a satellite hydrogen supply base for a fuel cell vehicle (FCV).
　１：　　　水蒸気改質システム
　１０：　　収容空間
　１１：　　原料圧縮機
　１２：　　脱硫器
　１３：　　第１給水予熱器
　１４：　　第２給水予熱器
　１５：　　第１水蒸気発生器
　１６：　　第２水蒸気発生器
　１７：　　改質炉
　１８：　　改質管
　１９：　　バーナ
　２０：　　ガス予熱器
　２１：　　空気予熱器
　２２：　　ＣＯ変成器
　２３：　　ガス冷却器
　２４：　　ドレイン分離器
　２５：　　ＰＳＡ水素分離装置
　２６：　　外管
　２７：　　内管
　２８：　　蓋部材
　２９：　　蓋部材
　３０：　　外側流路
　３１：　　内側流路
　３２：　　入口管
　３３：　　出口管
　３４：　　下部空間
　３５：　　蓋部材
　３６：　　入口配管
　３７：　　出口配管
　３８：　　燃焼用空気ヘッダ
　３９：　　煙突
　４０：　　吸着槽
　４１：　　真空ポンプ
　４２：　　補圧ポンプ
　４３：　　原ガス配管
　４４：　　オフガス配管
　４５：　　製品水素ガス配管
　４６：　　加圧水素ガス配管
　１００：　従来の水素製造システム
　１０１：　原料圧縮機
　１０２：　脱硫器
　１０３：　給水予熱器
　１０４：　廃熱回収ボイラ
　１０５：　改質炉
　１０６：　改質管
　１０７：　原料予熱器
　１０８：　過熱器
　１０９：　バーナ
　１１０：　空気予熱器
　１１１：　ＣＯ変成器
　１１２：　ガス冷却器
　１１３：　ＰＳＡ水素分離装置 1: Steam reforming system 10: Housing space 11: Raw material compressor 12: Desulfurizer 13: First feed water preheater 14: Second feed water preheater 15: First steam generator 16: Second steam generator 17: Modified Quality furnace 18: Reforming pipe 19: Burner 20: Gas preheater 21: Air preheater 22: CO converter 23: Gas cooler 24: Drain separator 25: PSA hydrogen separator 26: Outer pipe 27: Inner pipe 28 : Lid member 29: Lid member 30: Outer flow path 31: Inner flow path 32: Inlet pipe 33: Outlet pipe 34: Lower space 35: Lid member 36: Inlet pipe 37: Outlet pipe 38: Combustion air header 39: Chimney 40: Adsorption tank 41: Vacuum pump 42: Complementary pressure pump 43: Raw gas piping 44: Off-gas piping 45: Product hydrogen gas piping 46: Pressurized hydrogen gas Piping 100: Conventional hydrogen production system 101: Raw material compressor 102: Desulfurizer 103: Feed water preheater 104: Waste heat recovery boiler 105: Reforming furnace 106: Reforming pipe 107: Raw material preheater 108: Superheater 109: Burner 110: Air preheater 111: CO converter 112: Gas cooler 113: PSA hydrogen separator

Claims (13)

  1. 　炭化水素を含む原料ガスを水蒸気と反応させて、水素と一酸化炭素を少なくとも含む改質ガスを生成する複数の改質管を、断熱構造体で囲まれた筒状の改質炉内に夫々の軸方向を互いに平行にして並列に連結配置してなる改質器と、
    　前記改質器に供給する水蒸気を発生する蒸気発生器と、
    　前記改質ガスに含まれる一酸化炭素の少なくとも一部を水蒸気と反応させて二酸化炭素に変成させ、前記改質ガスより含有一酸化炭素濃度の低下した変成ガスを生成する変成器と、
    　燃料ガスを燃焼して前記改質炉内に熱供給を行う燃焼器と、を備えてなり、
    　前記改質管の夫々が、
    　　両端が閉じられた外管と、前記外管内に収容され一端が閉じ他端が開口した内管を同軸状に備え、且つ、
    　　前記外管の一端側に入口を備え、前記内管の一端側に出口を備え、且つ、
    　　前記外管と前記内管の間に形成された外側流路と前記内管内に形成された内側流路が、前記外管内の他端側において連通しており、且つ、
    　　少なくとも前記外側流路に改質触媒が充填されて構成され、
    　前記燃焼器が、前記改質炉内または前記改質炉の炉壁部の前記外管の他端側に設けられ、
    　前記改質器と筒状の前記変成器が、互いに隣接して、前記複数の改質管と筒状の前記変成器の夫々の軸方向を互いに平行にして、筒状の１つの収容空間内に設置されていることを特徴とする水蒸気改質システム。     A plurality of reforming pipes that generate a reformed gas containing at least hydrogen and carbon monoxide by reacting a raw material gas containing hydrocarbons with water vapor are respectively placed in a cylindrical reforming furnace surrounded by a heat insulating structure. A reformer formed by connecting and arranging the axes in parallel with each other in parallel,
    A steam generator for generating steam to be supplied to the reformer;
    A transformer that reacts at least part of the carbon monoxide contained in the reformed gas with water vapor to transform it into carbon dioxide, and generates a transformed gas having a reduced concentration of carbon monoxide from the reformed gas;
    A combustor that burns fuel gas and supplies heat into the reforming furnace,
    Each of the reforming tubes is
    An outer tube closed at both ends, and an inner tube accommodated in the outer tube and having one end closed and the other end opened coaxially; and
    An inlet on one end of the outer tube, an outlet on one end of the inner tube, and
    An outer channel formed between the outer tube and the inner tube and an inner channel formed in the inner tube communicate with each other on the other end side in the outer tube; and
    At least the outer channel is filled with a reforming catalyst,
    The combustor is provided in the other end side of the outer pipe in the reforming furnace or the furnace wall portion of the reforming furnace,
    The reformer and the tubular transformer are adjacent to each other, and the axial directions of the plurality of the reformer tubes and the tubular transformer are parallel to each other, so that the inside of the single accommodation space Steam reforming system characterized by being installed in
  2. 　前記改質管の軸心に垂直な平面における前記外管及び前記外側流路の各断面積が、軸心方向の中央部分より前記外管及び前記内管の前記一端側の方が当該中央部分の前記他端側の方より大きいことを特徴とする請求項１に記載の水蒸気改質システム。 The cross-sectional areas of the outer pipe and the outer flow path in a plane perpendicular to the axis of the reforming pipe are such that the one end side of the outer pipe and the inner pipe is closer to the central portion than the central portion in the axial direction. The steam reforming system according to claim 1, wherein the steam reforming system is larger than the other end side.
  3. 　前記改質器に供給される前記原料ガス中の炭素量に対する前記蒸気発生器から前記改質器に供給される水蒸気量のモル比が、１．７以上２．４以下となるように、前記改質器に供給される前記炭素量及び前記水蒸気量が調整されていることを特徴とする請求項１または２に記載の水蒸気改質システム。 The molar ratio of the amount of water vapor supplied from the steam generator to the reformer with respect to the amount of carbon in the raw material gas supplied to the reformer is 1.7 or more and 2.4 or less. The steam reforming system according to claim 1 or 2, wherein the amount of carbon and the amount of steam supplied to the reformer are adjusted.
  4. 　内槽部の外周を外槽部が取り囲む同心円筒容器を備え、
    　前記原料ガス中に含まれる硫黄成分を除去する脱硫器と前記変成器とが、前記外槽部と前記内槽部の何れか一方と他方に形成され、互いに熱交換可能に構成され、
    　前記改質器と前記同心円筒容器が、前記収容空間内に、互いに隣接して、前記複数の改質管と前記同心円筒容器の夫々の軸方向を互いに平行にして、設置されていることを特徴とする請求項１～３の何れか１項に記載の水蒸気改質システム。     Comprising a concentric cylindrical container that the outer tank part surrounds the outer periphery of the inner tank part,
    The desulfurizer for removing sulfur components contained in the raw material gas and the transformer are formed in either one of the outer tank part and the inner tank part and the other, and are configured to be able to exchange heat with each other,
    The reformer and the concentric cylindrical container are installed adjacent to each other in the housing space, with the axial directions of the plurality of reforming pipes and the concentric cylindrical container being parallel to each other. The steam reforming system according to any one of claims 1 to 3, characterized in that:
  5. 　前記変成器内に、前記蒸気発生器の少なくとも一部として、前記変成器の変成反応で発生した熱を利用して前記改質器に供給する水蒸気を発生する第１蒸気発生器を備えることを特徴とする請求項１～４の何れか１項に記載の水蒸気改質システム。 A first steam generator that generates steam to be supplied to the reformer using heat generated by a shift reaction of the shift transformer is provided as at least a part of the steam generator in the shift generator. The steam reforming system according to any one of claims 1 to 4, characterized in that:
  6. 　前記改質炉内で発生した燃焼排ガスを前記改質炉外に排気する排気路の途中に、前記蒸気発生器の少なくとも一部として、前記燃焼排ガスの廃熱を利用して前記改質器に供給する水蒸気を発生する第２蒸気発生器を備え、
    　前記第２蒸気発生器が、前記収容空間内に納まるように、前記改質炉の前記炉壁部の側面に沿って形成されていることを特徴とする請求項１～５の何れか１項に記載の水蒸気改質システム。     In the middle of the exhaust path for exhausting the combustion exhaust gas generated in the reforming furnace to the outside of the reforming furnace, the waste heat of the combustion exhaust gas is used as the reformer as at least a part of the steam generator. A second steam generator for generating steam to be supplied;
    6. The method according to claim 1, wherein the second steam generator is formed along a side surface of the furnace wall portion of the reforming furnace so as to be accommodated in the accommodating space. The steam reforming system described in 1.
  7. 　前記改質炉の前記断熱構造体の外側面に接して鋼板製外板が設けられ、
    　前記鋼板製外板に熱伝導可能に接して細管コイルが設けられ、
    　前記鋼板製外板と前記細管コイルにより、前記第２蒸気発生器に供給する水を、前記改質炉の前記断熱構造体から前記鋼板製外板に伝達された熱を利用して予熱する給水予熱器が形成されていることを特徴とする請求項１～６の何れか１項に記載の水蒸気改質システム。     A steel plate outer plate is provided in contact with the outer surface of the heat insulation structure of the reforming furnace,
    A thin tube coil is provided in contact with the steel plate outer plate so as to allow heat conduction,
    Water supplied to the second steam generator by the steel plate outer plate and the thin tube coil is preheated using heat transferred from the heat insulating structure of the reforming furnace to the steel plate outer plate. The steam reforming system according to any one of claims 1 to 6, wherein a preheater is formed.
  8. 　前記改質炉内で発生した燃焼排ガスを前記改質炉外に排気する排気路の途中に、前記燃焼排ガスの廃熱を利用して、前記燃焼器に供給する燃料ガス及び燃焼空気を予熱するガス予熱器と空気予熱器を備え、
    　前記ガス予熱器と前記空気予熱器が、前記収容空間内に納まるように、前記改質炉の前記炉壁部の側面に沿って形成されていることを特徴とする請求項１～７の何れか１項に記載の水蒸気改質システム。     Preheating the fuel gas and combustion air to be supplied to the combustor using the waste heat of the combustion exhaust gas in the middle of the exhaust path for exhausting the combustion exhaust gas generated in the reforming furnace to the outside of the reforming furnace With gas preheater and air preheater,
    The gas preheater and the air preheater are formed along a side surface of the furnace wall portion of the reforming furnace so as to be accommodated in the accommodating space. The steam reforming system according to claim 1.
  9. 　前記変成ガス中に含まれる水素以外のガスを吸着除去し、前記変成ガスより含有水素濃度の上昇した製品水素を生成するＰＳＡ分離装置を、前記収容空間外に備えることを特徴とする請求項１～８の何れか１項に記載の水蒸気改質システム。 2. A PSA separation device for generating product hydrogen having a hydrogen concentration higher than that of the modified gas by adsorbing and removing a gas other than hydrogen contained in the modified gas is provided outside the accommodation space. The steam reforming system according to any one of 1 to 8.
  10. 　前記ＰＳＡ分離装置が備える複数の吸着槽の夫々が、前記変成ガス中に含まれる一酸化炭素を化学的に吸着する化学吸着剤を備えることを特徴とする請求項９に記載の水蒸気改質システム。 The steam reforming system according to claim 9, wherein each of the plurality of adsorption tanks provided in the PSA separation device includes a chemical adsorbent that chemically adsorbs carbon monoxide contained in the metamorphic gas. .
  11. 　前記ＰＳＡ分離装置が、３槽の吸着槽と真空ポンプと補圧ポンプを備え、
    　前記真空ポンプと前記補圧ポンプが、同じ真空ポンプを兼用して構成されるか、或いは、個別のポンプで夫々構成され、
    　前記３槽の吸着槽の内の第１槽が吸着処理に供される１サイクルが４工程で構成され、
    　前記ＰＳＡ分離装置が、前記１サイクルの間、
    　第１工程で、前記３槽の吸着槽の内の第２槽と第３槽の槽内圧を均等化するために、前記第２及び第３槽の槽内間を連通させ、前記第２槽を減圧し、前記第３槽を昇圧し、
    　第２工程で、前記第２及び第３槽の槽内間を、前記捕圧ポンプを介して連通させ、前記第２槽を更に減圧し、前記第３槽を更に昇圧し、
    　第３工程で、前記第３槽を、前記製品水素の一部の水素を用いて加圧し、前記第２槽内に吸着された前記水素以外のガスを、前記真空ポンプを作動させて真空脱着してオフガスとして排出し、
    　第４工程で、前記第３槽に対する加圧を停止し、前記第２槽に対して、前記製品水素の一部の水素を用いて、吸着剤の洗浄と残留ガスのパージ処理を行うように構成されていることを特徴とする請求項９または１０に記載の水蒸気改質システム。     The PSA separation apparatus includes three adsorption tanks, a vacuum pump, and a supplementary pressure pump,
    The vacuum pump and the auxiliary pressure pump are configured by using the same vacuum pump, or are configured by individual pumps, respectively.
    One cycle in which the first tank among the three tanks is subjected to the adsorption process is composed of four steps,
    During the one cycle, the PSA separator
    In the first step, in order to equalize the internal pressure of the second tank and the third tank among the three adsorption tanks, the second tank and the third tank are communicated with each other, and the second tank The pressure in the third tank,
    In the second step, the inside of the tanks of the second and third tanks are communicated via the pressure pump, the second tank is further depressurized, the third tank is further pressurized,
    In the third step, the third tank is pressurized using a part of the product hydrogen, and the gas other than the hydrogen adsorbed in the second tank is vacuum desorbed by operating the vacuum pump. And exhaust it as off-gas,
    In the fourth step, pressurization to the third tank is stopped, and cleaning of the adsorbent and purging of residual gas are performed on the second tank by using a part of the hydrogen of the product hydrogen. It is comprised, The steam reforming system of Claim 9 or 10 characterized by the above-mentioned.
  12. 　請求項１～１１の何れか１項に記載の水蒸気改質システムを備える水素製造システムと、前記水素製造システムが生成する水素を消費して発電する発電装置を備え、
    　前記水素製造システムの水素ガス化効率が９０％以上であることを特徴とする発電システム。     A hydrogen production system comprising the steam reforming system according to any one of claims 1 to 11, and a power generation device that consumes hydrogen generated by the hydrogen production system to generate electric power,
    A power generation system, wherein the hydrogen gasification efficiency of the hydrogen production system is 90% or more.
  13. 　前記水素製造システムが、水素を燃料とする車両用の水素供給基地における水素供給設備を構成し、
    　前記発電装置が、前記水素供給基地内に設けられた、電気自動車に電力を供給する電力供給設備を構成することを特徴とする請求項１２に記載の発電システム。     The hydrogen production system constitutes a hydrogen supply facility in a hydrogen supply base for vehicles using hydrogen as fuel,
    The power generation system according to claim 12, wherein the power generation device constitutes a power supply facility that is provided in the hydrogen supply base and supplies power to an electric vehicle.
PCT/JP2016/087371 2016-02-01 2016-12-15 Steam reforming system and power generation system WO2017134940A1 (en)

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