JP2005015286A - Hydrogen production hybrid system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently produce hydrogen from a lower hydrocarbon gas without being accompanied by the large quantity of carbon dioxide. <P>SOLUTION: An aromatic manufacture type direct reformer 12 for producing hydrogen and an aromatic series from the lower hydrocarbon and a carbon manufacture type direct reformer or a steam reformer 50 for producing hydrogen and carbon from the lower hydrocarbon are hybridized. As a result, the discharge of carbon dioxide is suppressed and the hydrocarbon is fixed as the aromatic series and carbon by making up for defects that equilibrium conversion of the aromatic manufacture type direct reformer is low and the life of a catalyst is affected by gaseous impurities such as C<SB>2</SB>+. Thus, the efficient system with which the defects of each reformer are compensated and the fixation of carbon dioxide and the production of useful materials such as hydrogen, the aromatic series, filament carbon or the like are performed is realized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention reforms lower hydrocarbon fuels such as methane and natural gas with a catalyst to immobilize carbon dioxide as useful carbon nanofilaments (CNF) and aromatic compounds, and at the same time efficiently produce hydrogen. The present invention relates to a hydrogen fluoride production hybrid system.
[0002]
[Prior art]
Conventionally, there is a steam reforming method as a representative hydrogen generation method. FIG. 4 shows a schematic diagram of the steam reformer 50.
In the figure, 51 is a catalyst, 52 is a raw material gas, 53 is a tube-shaped reaction vessel, 54 is a heating burner, 55 is a heating furnace, and 56 is a product gas.
The catalyst 51 is filled in a number of reaction vessels 53, and the reaction vessels 53 are arranged in parallel in a heating furnace 55. In this part of the heating furnace 55, a plurality of heating burners 54 for heating the inside of the heating furnace 55 are arranged so that temperature distribution does not occur in the reaction vessel 53.
In this apparatus, water vapor and raw material hydrocarbons are introduced into the reaction vessel 53 and the inside of the heating furnace 55 is heated by the heating burner 54 to heat the catalyst 51 and reform the introduced gas in the reaction vessel 53. To do. The gas after the reaction is mainly hydrogen, carbon dioxide, and unreacted methane, and is discharged from the reaction vessel 53.
[0003]
An example of a hydrogen generation method using this steam reforming method will be described.
In the steam reforming method, nickel or the like is used as a catalyst, and methane as a raw material hydrocarbon is converted into S / C (number of steam moles / number of carbon moles of raw material hydrocarbons, generally 3 according to the gas composition at the outlet). ~ 5), water vapor is added by reacting under conditions of temperature: 450-900 (° C), pressure: 0-3.4 (MPaG), GHSV: 500-5000 (1 / hr). Carbon is produced (for example, conditions when SC11-9 or the like manufactured by Zude Chemie Catalysts Co., Ltd.) is used.
The reaction is represented by CH ₄ + 2H ₂ O → CO ₂ + 4H ₂ , and the conversion is about 80%.
[0004]
Further, there is a method represented by Patent Document 1 as a system for producing aromatics that is useful for aromatic production without reforming methane and generating carbon dioxide in the process, and Patent Document 2 as a system for producing carbon like carbon nanotubes. is there.
As shown in Patent Document 1, in the process of producing aromatics (mainly benzene) directly from lower hydrocarbons, a catalyst in which molybdenum is supported on ZSM5 type zeolite is typical, and the reaction is 6CH ₄ → C ₆ H ₆ + 9H. ₂ and the conversion is about 20% at 800 ° C. This reaction generally proceeds under conditions of temperature: 650 to 800 (° C.), pressure: 0 to 1 (MPaG), and GHSV: 500 to 10,000 (1 / hr).
Furthermore, as shown in Patent Document 2, the process for producing hydrogen and carbon nanotube-like carbon from lower hydrocarbons uses nickel, iron oxide or the like as a catalyst, the reaction is represented by CH ₄ → C + 2H ₂ , and the conversion rate is It reaches about 90% at 800 ° C. In general, the reaction proceeds under conditions of temperature: 400 to 800 (° C.), pressure: 0 to 1 (MPaG), GHSV: 500 to 10,000 (1 / hr).
[0005]
[Patent Document 1]
JP 2001-334151 A [Patent Document 2]
Japanese Patent No. 2838192 specification [0006]
[Problems to be solved by the invention]
However, since the conventional steam reformer is configured as described above, a large amount of carbon dioxide, which is a global warming gas, is produced simultaneously with hydrogen. For this reason, if the steam reformer is used as a hydrogen production system for supplying fuel cells, which is said to be the ultimate clean power generation system in the future, the burden on the global environment is no different from that of the current oil-dependent society. There is.
[0007]
Also, in the process of producing aromatics and hydrogen from lower hydrocarbons, the equilibrium conversion is low, so it is necessary to recover the unreacted gas and directly reform the aromatic production type again, and there is no carbon dioxide emission in the process However, as a system for obtaining the reaction heat at this time by burning the fuel, it is conceivable that the amount of carbon dioxide for heating is higher than that of the steam reforming method. Furthermore, the recovered gas has a drawback that it cannot stably exhibit catalytic performance unless the by-products are reduced and the methane purity is increased, and it is difficult to directly use natural gas or the like as a raw material.
[0008]
In addition, in the process of producing hydrogen and solid carbon from lower hydrocarbons, if reforming is carried out at an excessively high temperature in order to increase the conversion rate, there is a drawback that useful CNF is graphitized and loses its value as a product. The temperature for efficiently obtaining the CNF carbon is considered to be about 500 ° C. to 600 ° C., and the methane conversion rate at this time is about 50 to 60%.
[0009]
The present invention has been made against the background of the above circumstances, and reforms lower hydrocarbon fuels such as methane and natural gas with a catalyst to generate hydrogen, and at the same time, when the fuel is conventionally burned to obtain energy. Provides a highly efficient hydrogen generation system in which carbon components that should be emitted as carbon are fixed as useful aromatic compounds or carbon nanotube-like carbon, etc., and carbon dioxide emissions are reduced in the process compared to conventional steam reforming methods The purpose is to do.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 of the hydrogen production hybrid system of the present invention comprises an aromatic production type direct reformer in which an aromatic compound and hydrogen are produced from a lower hydrocarbon gas as a raw material, It is provided with a steam reformer that is subsequent to the aromatic production type direct reformer and generates hydrogen and carbon dioxide from the lower hydrocarbon gas.
[0011]
A method for producing a hybrid system for producing hydrogen according to claim 2, comprising: an aromatic production type direct reformer in which an aromatic compound and hydrogen are produced using a lower hydrocarbon gas as a raw material; and the aromatic production type direct reformer And a carbon production type direct reformer in which hydrogen and carbon are produced from a lower hydrocarbon gas.
[0012]
According to a third aspect of the present invention, there is provided a method for producing a hydrogen production hybrid system comprising: an aromatic production type direct reformer that produces an aromatic compound and hydrogen using a lower hydrocarbon gas as a raw material; and an aromatic production type direct reformer. A steam reformer in which hydrogen and carbon dioxide are produced from lower hydrocarbon gas in the latter stage, and hydrogen and carbon from lower hydrocarbon gas in the former stage or rear stage of the aromatic production type direct reformer. And a carbon production type direct reformer to be produced.
[0013]
According to a fourth aspect of the present invention, there is provided a method for producing a hydrogen production hybrid system according to any one of the first to third aspects, wherein an aromatic compound is separated from a gas sent from the aromatic production type direct reformer. It comprises a group separation means.
[0014]
The method for producing a hybrid system for producing hydrogen according to claim 5 is the invention according to any one of claims 1 to 4, wherein the unreacted raw lower hydrocarbon gas is separated from the gas reformed by the reformer in the previous stage. And an unreacted raw material separating means for refluxing a part or all of it to the former reformer.
[0015]
According to a sixth aspect of the present invention, there is provided a method for producing a hydrogen production hybrid system according to the fifth aspect of the invention, wherein the unreacted raw material separation means converts a part of the separated unreacted raw material lower hydrocarbon gas into a reformer at the preceding stage. While being refluxed, a part of the separated raw material lower gas can be supplied to the reformer at the subsequent stage.
[0016]
The hybrid system for producing hydrogen according to claim 7 is the invention according to claim 6, wherein the amount of the unreacted raw material lower hydrocarbon gas to be refluxed and the amount of the unreacted raw material lower hydrocarbon gas supplied to the subsequent reformer are adjusted. It is possible to do this.
[0017]
The method for producing a hybrid system for producing hydrogen according to claim 8 is characterized in that, in the invention according to any one of claims 1 to 7, a hydrogen purification means is provided in the rear stage of the reformer in the final stage.
[0018]
According to a ninth aspect of the present invention, in the method for producing a hydrogen production hybrid system according to the second aspect of the invention, the residual heat of the aromatic production type direct reformer can be used for heating the carbon production type direct reformer. It is characterized by.
[0019]
That is, the present invention includes an aromatic production type direct reformer and at least one of a steam reformer and a carbon production type direct reformer, so that a part of carbon in the hydrocarbon is useful as a chemical industrial raw material. In the process, carbon dioxide is fixed as CNF, and unreacted lower hydrocarbons such as methane are reformed into hydrogen and carbon by steam reforming method or carbon production type direct reforming method. This makes it possible to produce hydrogen by reforming raw materials with high efficiency in terms of heat and materials, and at the same time, it is possible to fix useful hydrocarbons as aromatic and carbon.
[0020]
In the present invention, lower hydrocarbons are used as a raw material gas. The type is not limited to a specific type, but typically includes methane. Further, the lower hydrocarbon as a raw material may be composed of a plurality of types in addition to a single type.
The aromatic production type direct reformer is one in which an aromatic compound and hydrogen are mainly produced from a lower hydrocarbon gas as a raw material, and the configuration is not limited to a specific one. Usually, the thing using the catalyst which carry | supported the support | carrier with 1 or a some metal as a catalyst material is illustrated. In reforming, an aromatic compound and hydrogen are generated from lower hydrocarbons as raw materials, and ethane, ethylene, and the like are also generated as by-products. In addition, unreacted raw material lower hydrocarbons remain in the reformed gas.
[0021]
Further, the steam reformer generally causes a reaction by bringing steam and a raw material lower hydrocarbon into contact with a catalyst, and mainly produces hydrogen and carbon monoxide or carbon dioxide. In addition, by-products are generated, and unreacted raw material lower hydrocarbons remain in the reformed gas. A steam reformer may be provided with a steam generator.
[0022]
The carbon production type direct reformer generates hydrogen and solid carbon (for example, carbon nanotube-like), and usually reacts the raw material lower hydrocarbon using an appropriate catalyst. Other by-products may be generated in this reaction. In addition, unreacted raw material lower hydrocarbons remain in the reformed gas.
[0023]
In the present invention, the aromatic production type direct reformer is essential, and at least one of a steam reformer and a carbon production type direct reformer is provided. The steam reformer is arranged at the subsequent stage of the aromatic production direct reformer, and after fixing some elements of the raw material lower hydrocarbon as a useful aromatic compound by the aromatic production direct reformer, Modification is made. Thereby, hydrogen is efficiently produced while suppressing the amount of carbon dioxide generated in the entire system. In addition, according to this system, it is not necessary to recirculate unreacted gas containing impurities that has been reformed in the aromatic production type direct reformer to the aromatic production type direct reformer. Thus, it is possible to prevent deterioration of the properties of the aromatic production type direct reformer.
[0024]
In addition, since the carbon production type direct reformer does not normally assume the production of carbon dioxide, it may be installed either before or after the aromatic production type direct reformer. In this system, carbon in the raw material lower hydrocarbon is immobilized as useful CNF and an aromatic compound, and the production of carbon dioxide is suppressed. In addition, when the carbon production type direct reformer is installed in the front stage of the aromatic production type direct reformer, the raw material lower hydrocarbon is pretreated by the carbon production type direct reformer. It becomes possible to supply high raw material lower hydrocarbons to an aromatic production type direct reformer.
[0025]
In addition, while providing an aromatic separation means for separating the aromatic compound from the gas sent from the aromatic production type direct reformer and taking it out of the system, effective use of the aromatic compound can be achieved, It is possible to prevent the aromatic compound from adversely affecting the subsequent stage.
[0026]
In addition, the reformed gas contains unreacted raw material lower hydrocarbon, and this raw material lower hydrocarbon is supplied to the subsequent stage and processed, but the unreacted raw material lower hydrocarbon is treated from the reformed gas. Separation means can be provided for separating and supplying to the former reformer. Part of the unreacted raw material separated by the separation means can be taken out of the system as fuel or the like. In addition, a part of the separated unreacted raw material can be allocated to a subsequent reformer. The amount of aromatic compound produced and the amount of hydrogen produced can be adjusted by adjusting the amount refluxed by the separation means and the amount supplied to the reformer at the subsequent stage.
[0027]
In addition, since the temperature of the reaction can be set lower than the reaction temperature of the aromatic production type direct reformer in the system where the carbon production type direct reformer is arranged, the residual heat of the aromatic production type direct reformer is effectively used. By using it, hydrogen, aromatics and carbon can be produced more efficiently than existing steam reforming systems.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
An embodiment of the present invention will be described below with reference to FIG. In addition, about the structure similar to a conventional apparatus, the same code | symbol is attached | subjected and the description is abbreviate | omitted or simplified.
The system of this embodiment uses a biogas raw material as a raw material lower hydrocarbon, and its components are composed of 60% CH ₄ and 40% CO ₂ .
In the present system, a desulfurization apparatus 10 that introduces the above raw material to remove sulfur and a CO ₂ removal pretreatment apparatus 11 for removing carbon dioxide are arranged in series. It is not particularly limited construction of desulfurizer 10 to remove the H _{2 S} by the use of, for example, iron-based catalyst. The CO ₂ removal pretreatment apparatus 11 is not limited to a specific configuration in the present invention, but can be configured by, for example, MEA absorption, PSA, or membrane separation, and CO ₂ contained in the raw material is almost removed by this apparatus. .
[0029]
An aromatic production type direct reformer 12 is connected to the subsequent stage of the CO ₂ removal pretreatment apparatus 11. The aromatic production type direct reformer 12 can be constituted by, for example, a direct reformer in which a catalyst in which a metal such as molybdenum is supported on a ZSM5 type zeolite having a pore system of about 5 mm is filled. At the subsequent stage of the aromatic production type direct reformer 12, an aromatic separation means 13 for separating the aromatic compound produced by the aromatic production type direct reformer 12 is connected. The aromatic separation means 13 is a separation and purification device for separating aromatics (benzene, toluene, xylene: BTX, and naphthalene) from the gas containing hydrogen and unreacted gas generated in the direct reforming unit 2. Aromatic compounds can be separated by distillation or the like. An aromatic removal unit 14 is installed at the subsequent stage of the aromatic separation unit 13. The aromatic removing unit 14 removes an aromatic compound (hereinafter referred to as BTX) by activated carbon adsorption or the like. The trace amount BTX that cannot be completely separated after the BTX separation may affect the subsequent system, and is therefore completely removed by the aromatic removal unit 14. A compressor 15 is disposed downstream of the aromatic removal unit 14 and the pressure of the gas is increased to a pressure required for methane separation, and the gas is introduced into the separation device 16 such as a membrane.
[0030]
A CH ₄ separation unit 16 is connected to the subsequent stage of the compressor 15 as an unreacted raw material separation unit. The CH ₄ separation unit 16 includes a PSA and a separation membrane, and can separate raw methane. The separation side of the CH ₄ separation unit 16 is connected to the reflux path 17 including the compressor 17a, and the gas on the through side is configured to be supplied to the steam reformer 50 and the outside of the system. Further, the separation side CH ₄ of the CH ₄ separation unit 16 may be allocated on the reflux path 17 side, the steam reformer 50 side, and outside the system. Through gas (for example, CH ₄ 50%, H _{2 and} other 50%) supplied to the outside of the system is used as fuel. The reflux path 17 is connected to the gas introduction side of the aromatic production type direct reformer 12. A downstream side of the steam reformer 50 is connected to a hydrogen purifier 18. The separation method in the hydrogen purifier 18 is not particularly limited in the present invention, and for example, an appropriate method such as a membrane separation method that allows PSA or hydrogen to permeate can be employed.
[0031]
Next, the operation of this system will be described.
The raw biogas is desulfurized by the desulfurization device 12, de-CO ₂ is removed by the CO ₂ removal pretreatment device 11, and is supplied to the aromatic production type direct reformer 12. In the aromatic production type direct reformer 12, for example, a catalytic reaction is performed under conditions of 750 to 800 ° C. and 5 atm to generate byproducts such as hydrogen, an aromatic compound, and ethane. Some raw lower hydrocarbons remain unreacted without reacting. These gases are discharged from the aromatic production type direct reformer 12 and introduced into the aromatic separation unit 13. In the aromatic separation unit 13, an aromatic compound (BTX) such as benzene is separated and taken out of the system. Thereby, for example, 20 to 40% of methane is immobilized as BTX. The residue from which the aromatic compound has been separated is further removed by a minute amount of BTX by the aromatic removing unit 14, and further, the moisture is removed by the moisture removing device 15 and supplied to the CH ₄ separating unit 16. In the CH ₄ separation unit 16, unreacted CH ₄ (for example, a purity of 98% or more and a recovery rate of 80%) is separated, a part is supplied to the reflux path 17, and the other part is removed from the steam reformer 50 and the system. Allocated. The through gas is supplied to the outside of the system and the steam reformer 50. Gas outside the system is used as fuel. Note that the CH ₄ separation unit 16 may be configured to adjust the separation gas amount supplied to the reflux path 17 and the gas amount supplied to the steam reformer 50. The adjustment can be performed, for example, by arranging the valve and adjusting the opening. The CH ₄ sent to the reflux path 17 is supplied to the aromatic production type direct reformer 12 and used for the aromatic direct reforming reaction to improve the actual conversion rate.
[0032]
In steam reformer 50 is supplied with steam with CH _4, for example, 500 to 800 ° C., hydrogen and carbon dioxide, carbon monoxide is purified by reforming under conditions of 4 atm. These gases are supplied to the hydrogen purifier 18 where carbon dioxide, carbon monoxide and water vapor are removed and hydrogen is separated and used as production hydrogen.
According to this system, hydrogen can be produced at the same time that about 20 to 40% of carbon in the raw material methane is immobilized as an aromatic.
[0033]
In a conventional system consisting only of an aromatic production type direct reformer, the raw material lower hydrocarbon aromatic production type direct reformer is reformed into an aromatic compound mainly composed of hydrogen and benzene. However, if the reforming temperature is 800 ° C., for example, the theoretical equilibrium conversion is about 20%, so that unreacted methane is discharged as 80% off-gas. When this process is used alone as a hydrogen generator, it is necessary to pass this unreacted gas through the reactor five times in order to reform the raw material into 100% hydrogen and aromatics. However, with the existing technology, in order to proceed with the reaction, it is necessary to cool the unreacted gas exiting the aromatic production type direct reformer and separate the product hydrogen with a separator, and then to remove the unreacted methane again. Thermal efficiency is poor because it must be heated to 800 ° C. Furthermore, a small amount of by-products may return to the circulating gas during product separation and accumulate in the raw material gas, and the reforming performance may lack stability. However, according to the configuration of the present invention, unreacted gas containing impurities after purification of methane (for example, methane 50%, hydrogen and C ₂ + other 50%) is reformed by a steam reformer disposed in the subsequent stage to generate hydrogen. Therefore, it is not necessary to pass unreacted methane containing impure gas that affects the stability of performance through the aromatic production type direct reformer, so that most of the raw materials can be processed efficiently and carbon dioxide. It is possible to produce a system capable of producing hydrogen while suppressing carbon emission, and further producing an aromatic compound useful as a raw material for chemical industry.
[0034]
(Embodiment 2)
Next, another embodiment will be described with reference to FIG.
In addition, this embodiment is the same as that of the said embodiment except having changed the steam reformer 50 in the said embodiment into the carbon production type direct reformer 20, and those structures attach | subject the same code | symbol and give the description. Is omitted or simplified.
The carbon production type direct reformer 20 can be configured by including a catalyst in which a catalyst metal such as nickel or iron oxide is supported on a porous carrier such as silica or alumina.
In the same manner as in the above embodiment, the raw material methane is reformed by the aromatic production direct reformer 12, and a gas containing unreacted methane is introduced into the carbon production direct reformer 20 for reforming. The reforming is performed, for example, at 500 to 800 ° C. and 4 atm. This reaction produces hydrogen and solid carbon. In this system, hydrogen can be produced at the same time that about 50 to 90% of carbon in the raw material methane is immobilized as an aromatic or carbon.
[0035]
In the hybrid system of an aromatic production direct reformer and a steam reformer shown in the above embodiment, methane is aromatized in the preceding aromatic production direct reformer from the viewpoint of fixing carbon dioxide. It is only fixed as a tribe. However, in this embodiment, the aromatic carbon direct reformer and the carbon production direct reformer are hybridized via a methane separation device, so that the amount of carbon dioxide discharged in the process becomes zero, and the heat of the previous stage is further reduced. Can be used in the latter stage (carbon production type direct reformer) with low reaction temperature, and the carbon dioxide emissions for heating can be suppressed by using a part of the methane separation and purification unit as fuel for the shortage Can be built.
[0036]
(Embodiment 3)
Next, another embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the structure similar to each said embodiment, and the description is abbreviate | omitted or simplified.
In this embodiment, the carbon production type direct reformer 20 is installed in the preceding stage of the aromatic production type direct reformer 12, and natural gas is used as the raw material lower hydrocarbon. For this reason, in this system, unlike the above embodiment, the desulfurization apparatus 10 and the CO ₂ removal pretreatment apparatus 11 are omitted. The source gas contains, for example, 85% CH ₄ and 15% C ₂ +. In the carbon production type direct reformer 20, hydrogen and solid carbon are generated from the raw material gas as in the above embodiment, and the generated gas and the unreacted raw material gas are discharged. The carbon production type direct reformer 20 fixes 50 to 90% of methane as carbon.
[0037]
A CH ₄ separation unit 16 is installed at the rear stage of the carbon production type direct reformer 20, and about 98% (about 80% recovery rate) of unreacted CH ₄ separated by the separation unit 14 is refluxed. It is refluxed to the carbon production type direct reformer 20 through the passage 17 and used for improving the conversion rate. The through gas of the CH ₄ separation unit 16 and the separated unreacted CH ₄ are distributed and supplied to the aromatic production type direct reformer 12. A part of the through gas in the CH ₄ separation section 16 is used as a fuel for the heat necessary for the reaction of the carbon production type direct reformer 20, thereby fixing CO ₂ inevitably exhausted conventionally with high efficiency. Can be In the aromatic production type direct reformer 12, hydrogen and BTX are generated as in the above embodiment. The residual heat generated in the aromatic production direct reformer 12 can be used as a heating source for the carbon production direct reformer 20.
[0038]
An aromatic separation unit 13 is connected to the subsequent stage of the aromatic production type direct reformer 12, and the generated BTX is separated. The separation unit 13 immobilizes 20 to 40% of methane as BTX. The remaining gas from which BTX has been separated by the separation unit 13 is separated by the hydrogen purifier 18 and supplied as production hydrogen. The remaining gas in the hydrogen purifier 18 can be used as a fuel for heating, and unreacted raw material gas is taken out from the remaining gas and returned to the carbon production type direct reformer 20 through the reflux path 19. May be.
[0039]
According to this embodiment, when the raw material is natural gas, the C ₂ + component has an effect of promoting the deterioration of the aromatic reforming type direct reforming catalyst. Since the carbon production type direct reformer 20 can promote the reaction without problems even with C ₂ + components, the carbon production type direct reformer 20 can be expected to be effective as a pretreatment device for C ₂ + removal. It is not necessary to remove the C ₂ + component in the natural gas by placing the gas in the front stage of the aromatic production type direct reformer.
[0040]
【The invention's effect】
As described above, according to the present invention, the aromatic production type direct reformer and the steam reformer or the carbon production type direct reformer are arranged in series, so that the equilibrium of the aromatic production type direct reformer is achieved. Low conversion rate, C2 + etc. impure gas affects the life of the catalyst, suppresses carbon dioxide emission, immobilizes hydrocarbons to aromatics and carbon, and is thermally and materially efficient system There is an effect that can be configured.
[Brief description of the drawings]
FIG. 1 is a system flow diagram of a system that is an embodiment of the present invention and includes a front-stage aromatic production-type direct reformer and a rear-stage steam reformer.
FIG. 2 is a system flow diagram of a system that is another embodiment and includes a front-stage aromatic production-type direct reformer and a rear-stage carbon production-type direct reformer.
FIG. 3 is a system flow diagram of a system that is another embodiment and includes a front-stage carbon production-type direct reformer and a rear-stage aromatic production-type direct reformer.
4A and 4B are schematic views showing a conventional steam reformer, in which FIG. 4A is a perspective view, and FIG. 4B is an enlarged view of a portion B in FIG.
[Explanation of symbols]
12 Aromatic production type direct reformer 13 Aromatic separation unit 16 CH ₄ separation unit 17 Reflux path 18 Hydrogen purifier 20 Carbon production type direct reformer 50 Steam reformer

Claims (9)

An aromatic production type direct reformer in which an aromatic compound and hydrogen are produced using a lower hydrocarbon gas as a raw material, and hydrogen and carbon dioxide from the lower hydrocarbon gas in the latter stage of the aromatic production type direct reformer And a steam reformer that generates water. An aromatic production type direct reformer in which an aromatic compound and hydrogen are produced using a lower hydrocarbon gas as a raw material, and hydrogen from the lower hydrocarbon gas in the front stage or the rear stage of the aromatic production type direct reformer A hydrogen production hybrid system comprising a carbon production type direct reformer for producing carbon. An aromatic production type direct reformer in which an aromatic compound and hydrogen are produced using a lower hydrocarbon gas as a raw material, and hydrogen and carbon dioxide from the lower hydrocarbon gas in the latter stage of the aromatic production type direct reformer And a carbon production type direct reformer in which hydrogen and carbon are produced from a lower hydrocarbon gas in the front stage or the rear stage of the aromatic production type direct reformer. A hydrogen production hybrid system characterized by The hydrogen production hybrid system according to any one of claims 1 to 3, further comprising aromatic separation means for separating an aromatic compound from a gas sent from the aromatic production type direct reformer. It comprises an unreacted raw material separation means for separating unreacted raw material lower hydrocarbon gas from the gas reformed by the former reformer and refluxing part or all of it to the former reformer. The hydrogen production hybrid system according to any one of claims 1 to 4. The unreacted raw material separating means can recirculate a part of the separated unreacted raw material lower hydrocarbon gas to the former reformer and supply a part of the separated raw material lower gas to the latter reformer. The hydrogen production hybrid system according to claim 5, wherein: The hydrogen production hybrid system according to claim 6, wherein the amount of the unreacted raw material lower hydrocarbon gas to be refluxed and the amount of the unreacted raw material lower hydrocarbon gas supplied to the reformer at the subsequent stage can be adjusted. The hydrogen production hybrid system according to any one of claims 1 to 7, further comprising a hydrogen purification means in a subsequent stage of the reformer in the final stage. 3. The hydrogen production hybrid system according to claim 2, wherein the residual heat of the aromatic production direct reformer can be used for heating the carbon production direct reformer.

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