Ammonia-hydrogen blend fuel production device, fuel supply system, and hydrogen production method

Abstract

[Problem] To provide: an ammonia-hydrogen mixed fuel production apparatus capable of stably obtaining hydrogen from ammonia even when there is a change in the required ratio of fuel; and a fuel supply system. [Solution] An ammonia-hydrogen mixed fuel production apparatus 1010A comprises: an oxygen separation device 13 that separates oxygen (O2) 12 at a desired concentration from air 11; a reforming reactor 15 that converts ammonia (NH3) supplied from a raw material supply unit 14 into hydrogen (H2) by using the oxygen having the desired concentration from the oxygen separation device 13; and a gas component analyzer 17 that measures the concentration of one or both of hydrogen and ammonia in a reformed gas 16 from the reforming reactor 15.

Description

[Technical Field]

[0001] The present invention relates to an apparatus for producing ammonia-hydrogen mixed fuel, a fuel supply system, and a method for producing hydrogen. [Background technology]

[0002] Recently, technologies for utilizing ammonia have been attracting attention in the drive to achieve carbon neutrality. Incidentally, one example of a method for producing hydrogen (H2) from ammonia (NH3) is the ammonia decomposition method (see Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-144912 [Patent Document 2] Japanese Patent Publication No. 2023-83706 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the proposed decomposition method for obtaining hydrogen from ammonia disclosed in Patent Document 1 requires the use of an ammonia decomposition device that supplies heat by heating from outside the reactor. This ammonia decomposition device using external heating uses, for example, a burner to mix air (oxygen) with a mixture of ammonia (NH3) and H2 / N2, which is the off-gas from a PSA (Pressure Swing Adsorption) device, and combust it. However, ammonia, which is the main fuel, has a slower combustion rate than fuels such as methane, and there are issues with not only reliable ignition and combustion stabilization, but also suppressing the generation of nitrogen oxides.

[0005] Incidentally, the fuel composition (hydrogen / ammonia composition ratio) and flow rate may fluctuate depending on the requirements of downstream boilers, gas engines, industrial furnaces, etc. When the turndown is large (for example, the turndown ratio fluctuates from 100% to 20%, or the hydrogen ratio fluctuates from 100% to 20%), it becomes difficult to stably burn the ammonia by external heating or to quickly respond to fluctuations when converting ammonia to hydrogen in an ammonia cracker.

[0006] In an ATR (Autothermal Reformer) device that oxidatively decomposes ammonia, ammonia is oxidized by oxygen in the oxidative decomposition catalyst section. Self-heating due to oxidation causes the ammonia to undergo oxidative decomposition and decomposition reactions in the ATR catalyst section, resulting in reforming into hydrogen. In the prior art technology described in Patent Document 2, ammonia itself, which is the raw material for ammonia reforming, is oxidized on the catalyst. Therefore, the catalyst must be heated to 200°C or higher for oxidation to occur, so the catalyst or raw material gas must be preheated in advance.

[0007] In addition, the target of this invention is 100m per hour. 3 ~2,000m 3 Small- to medium-sized systems capable of generating hydrogen produce fuel for furnaces, gas engines, and boilers, which have large load fluctuations and frequent DSS (Daily Start and Stop), so they need to respond quickly to load fluctuations and DSS. Furthermore, because they are small- to medium-sized, the reactor size is small, and if there is a lot of heat released from the reactor, the amount of ammonia oxidation must be increased to compensate for the heat required for the ammonia decomposition reaction, resulting in lower hydrogen yield and thermal efficiency. Furthermore, in order to package the system, the number of devices must be reduced and the reactor must be compact.

[0008] Furthermore, when hydrogen is supplied to boilers, industrial furnaces, etc., these are subject to frequent turndown, shutdown, and startup, so a self-sustaining system that can be easily and quickly adapted is desirable.In the case of conventional technology, these devices require heating to 200°C or higher at startup, at which point the oxidative decomposition reaction can begin, so separate heating equipment must be installed, which makes the equipment more complex and makes it difficult to adapt quickly.

[0009] In view of the above problems, the present invention provides an ammonia-hydrogen mixed fuel production device, a fuel supply system, and a method for producing hydrogen, which are capable of stably and quickly obtaining hydrogen from ammonia even when the required composition ratio or amount of fuel changes. [Means for solving the problem]

[0010] (1) An apparatus for producing ammonia-hydrogen mixed fuel according to one embodiment of the present invention comprises: an oxygen supply unit that supplies oxygen at a desired concentration; a raw material supply unit that supplies ammonia; Using oxygen at a desired concentration from the oxygen supply unit The aforementioned a reforming reactor for converting ammonia into hydrogen to produce a reformed gas; a combustible gas inlet for supplying a combustible gas other than ammonia to the reforming reactor; a gas component analyzer that measures the concentration of either or both of hydrogen and ammonia in the reformed gas from the reforming reactor; Equipped with Along with the reforming reactor has a first catalyst and a second catalyst, The first catalyst is a platinum catalyst, and the second catalyst is NH 3 ATR catalyst alone or the above NH 3 ATR catalyst and NH 3 It is an ammonia reforming catalyst that is combined with a cracking catalyst. It is characterized by:

[0011] (2) Another aspect of the ammonia-hydrogen mixed fuel production apparatus according to the present invention is The oxygen supply unit is characterized in that it is an oxygen separator that separates oxygen from air to a desired concentration.

[0012] (3) Another aspect of the ammonia-hydrogen mixed fuel production apparatus according to the present invention is The oxygen supply unit in the supplied air Adsorption method to remove moisture by adsorption or cooling to below 20°C Remove cooling method It is characterized by being an air dryer.

[0013] (4) Another aspect of the ammonia-hydrogen mixed fuel production apparatus according to the present invention is The oxygen supply unit, with respect to the supply amount of the ammonia, It is characterized by adding 3 to 20% by volume of oxygen.

[0014] (5) Another aspect of the ammonia-hydrogen mixed fuel production apparatus according to the present invention is The amount of oxygen supplied from the oxygen supply unit is controlled based on the concentration of either or both of the hydrogen and the ammonia from the gas component analyzer.

[0015] (6) Another aspect of the ammonia-hydrogen mixed fuel production apparatus according to the present invention is The present invention is characterized in that a bypass line for supplying the ammonia from the raw material supply unit is provided between the reforming reactor and a measurement point of the gas component analyzer on the downstream side of the reforming reactor.

[0016] (7) Another aspect of the ammonia-hydrogen mixed fuel production apparatus according to the present invention is a bypass line for supplying ammonia from a raw material supply unit between the reforming reactor and a measurement point of the gas component analyzer on the downstream side of the reforming reactor; a storage tank provided between an ammonia introduction position of the bypass line and the reforming reactor, The gas composition of the reformed gas and ammonia is adjusted in accordance with the composition ratio of ammonia and hydrogen measured by the gas component analyzer and the required fuel composition ratio.

[0017] (8) Another aspect of the ammonia-hydrogen mixed fuel manufacturing apparatus according to the present invention is The reforming reactor a housing having an inlet for introducing ammonia and a flammable gas other than ammonia, and an outlet for discharging a generated gas; The gas is disposed inside the housing and introduced through the inlet. The aforementioned Generates heat by burning combustible gases consisting of a platinum catalyst a first catalyst portion including a first catalyst; The catalyst is disposed between the first catalyst portion and the outlet, is heated by the heat generated in the first catalyst portion, and generates hydrogen from ammonia. NH 3 ATR catalyst alone or the above NH 3 ATR catalyst and NH 3 It is an ammonia reforming catalyst that is combined with a cracking catalyst. and a second catalyst portion including a second catalyst.

[0018] (9) Another aspect of the ammonia-hydrogen mixed fuel production apparatus according to the present invention is The first catalyst portion is disposed between the inlet and the second catalyst portion.

[0019] (10) Another aspect of the ammonia-hydrogen mixed fuel production apparatus according to the present invention is The aforementioned Modification The reactor is characterized by comprising a dispersion section between the first catalyst section and the second catalyst section, which disperses the gas flowing out from the first catalyst section toward the second catalyst section.

[0020] (11) Another aspect of the ammonia-hydrogen mixed fuel production apparatus according to the present invention is an outlet flow path for discharging hydrogen from the outlet; a tank provided in the outflow passage for storing the outflowed hydrogen; The hydrogen supply system is characterized by comprising a return flow path that branches off from the branching portion of the outflow flow path and returns the hydrogen to the inlet.

[0021] (12) Another aspect of the fuel supply system according to the present invention is The ammonia-hydrogen mixed fuel production device (1) or (2) is used to supply ammonia reformed fuel to the fuel demand side.

[0022] (13) Another aspect of the method for producing hydrogen according to the present invention comprises: An introduction gas containing ammonia and a flammable gas other than ammonia Modification introducing the mixture into a reactor; a combustion step of selectively combusting the combustible gas in the introduced gas with a first catalyst; a second catalyst heating step of heating a second catalyst that generates hydrogen from ammonia using heat generated in the combustion step; a reforming step of stopping the introduction of the combustible gas after the temperature of the second catalyst reaches a predetermined temperature, and generating hydrogen from ammonia using the second catalyst; the reforming reactor comprises a first catalyst and a second catalyst; The first catalyst is a platinum catalyst, and the second catalyst is NH 3 ATR catalyst alone or the above NH 3 ATR catalyst and NH 3 It is an ammonia reforming catalyst that is combined with a cracking catalyst. It is characterized by: [Effects of the Invention]

[0023] According to the present invention, even when the required ratio of fuel changes, hydrogen can be stably obtained from ammonia. According to the present disclosure, it is possible to provide a reactor and a method for producing hydrogen with high thermal efficiency that can quickly respond to load fluctuations and start-up / shutdown on the demand side. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram of an apparatus for producing ammonia-hydrogen mixed fuel according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of an apparatus for producing an ammonia-hydrogen mixed fuel according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a schematic diagram of an apparatus for producing ammonia-hydrogen mixed fuel according to a third embodiment of the present invention. [Figure 4] FIG. 10 is a schematic diagram of an apparatus for producing ammonia-hydrogen mixed fuel according to a fourth embodiment of the present invention. [Figure 5A] FIG. 10 is a cross-sectional view showing the internal structure of a reactor according to a fifth embodiment. [Figure 5B] FIG. 10 is a structural diagram of a dispersion section installed inside a reactor according to a fifth embodiment. [Figure 5C] FIG. 10 is a structural diagram of another dispersion part installed inside the reactor of the fifth embodiment. [Figure 5D] FIG. 10 is a cross-sectional view showing the internal structure of another reactor according to the fifth embodiment. [Figure 6] FIG. 2 is a perspective view of a first catalyst portion, illustrating the size of the first catalyst portion. [Figure 7] FIG. 2 is a perspective view of a second catalyst portion, illustrating the size of the second catalyst portion. [Figure 8] FIG. 6 is a diagram illustrating the temperature gradient between the second catalyst portion and the housing. [Figure 9] FIG. 10 is a diagram showing a structure for starting up a reactor using at least a portion of the hydrogen produced in the second catalyst section. [Figure 10] 10 is a graph showing the temperature distribution inside the reactor when combustible gas is combusted in the catalyst section under specific reaction conditions in the fifth embodiment. [Figure 11] 1 is a graph showing the temperature distribution inside a reactor when ammonia reforming is carried out in the reactor without adding a combustible gas. [Figure 12] 1 is a flowchart showing a method for producing hydrogen. [Figure 13] FIG. 10 is a cross-sectional view showing the internal structure of a reactor according to a sixth embodiment. [Figure 14] FIG. 10 is a cross-sectional view showing the internal structure of a reactor according to a seventh embodiment. [Figure 15] FIG. 15 is a cross-sectional view taken along the line AA in FIG. 14, showing a cross-sectional view of a second catalyst section installed in the second stage. DETAILED DESCRIPTION OF THE INVENTION

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiments of this specification, the same components are designated by the same reference numerals throughout.

[0026] [First embodiment] Fig. 1 is a schematic diagram of an apparatus for producing ammonia-hydrogen mixed fuel according to a first embodiment of the present invention. As shown in Fig. 1, the apparatus 1010A for producing ammonia-hydrogen mixed fuel according to this embodiment includes an oxygen separator 1013, which is an oxygen supply unit that separates oxygen (O2) from air 1011 to a desired concentration, a reforming reactor 1015 that converts ammonia (NH3) supplied from a raw material supply unit 1014 into hydrogen (H2) using the oxygen of the desired concentration from the oxygen separator 1013, and a gas component analyzer 1017 that measures the concentration of either or both of hydrogen and ammonia in a reformed gas 1016 from the reforming reactor 1015.

[0027] The raw material supply unit 1014 supplies ammonia (NH3) as a raw material, and the ammonia (NH3) is supplied from the raw material supply unit 1014 to the reforming reactor 1015 via an ammonia supply line L1. Further, the reformed gas 1016 from the reforming reactor 1015 is discharged via a reformed gas discharge line L2 and used as fuel 1018 on the external demand side X.

[0028] Also provided is an oxygen separator 1013 that obtains oxygen from air 1011, and the separated oxygen is supplied to the ammonia supply line L1 via an oxygen supply line L3. Examples of this oxygen separator 1013 include a cryogenic separator, a pressure swing adsorption (PSA) apparatus, and a membrane separator, but the present invention is not limited to these. In the following description, a pressure swing adsorption apparatus (hereinafter also referred to as "PSA") will be described as an example, but is not limited thereto.

[0029] In addition, a gas composition analyzer 1017 is installed in the reformed gas discharge line L2 to measure the composition ratio (NH3 / H2) of ammonia (NH3) and hydrogen (H2) which is the fuel 1018, or the gas composition of either one of them, to measure the gas composition.

[0030] Examples of the gas component analyzer 1017 include a hydrogen detector that detects hydrogen, an ammonia detector that detects ammonia, and an ammonia-hydrogen composition ratio detector that detects the composition ratio of hydrogen and ammonia, but the present invention is not limited to these. Here, the main analyzers used as the gas component analyzer 1017 may be, for example, a gas chromatograph (H2, NH3 gas), a thermal conductivity gas analyzer (H2 gas), an infrared absorption spectrophotometer (NH3 gas), etc., but are not limited to these in the present invention.

[0031] In this way, the composition ratio (NH3 / H2) in the reformed gas 1016 obtained by reforming the raw material ammonia in the reforming reactor 1015 is measured by the gas component analyzer 17, and the fuel composition required on the downstream demand side X is measured continuously or intermittently. This measurement may be sent online to a separate control device for automatic control. As an example, a control device (not shown) may be configured to correct the difference between the fuel composition requested by the demand unit X and the measured fuel composition.

[0032] In this embodiment, it is preferable to add 3 to 20% by volume, more preferably 5 to 17% by volume, of oxygen (O2) to the amount of ammonia (NH3) supplied. This is because adding less than 3% by volume reduces the hydrogen reforming ratio, which is undesirable. Adding more than 20% by volume also undesirably increases the oxidation rate beyond the amount of heat required for ammonia decomposition, resulting in a decrease in the H2 yield and thermal efficiency.

[0033] Here, to produce hydrogen from ammonia, as shown in the following formula (1), in the case of external heating, the endothermic heat is burned by burning NH3 / N2 in a heating furnace and supplied to the reaction tube. NH3→0.5N2+1.5H2 endotherm △H=+45.9 kJ / mol …(1) However, as the NH3 decomposition reaction progresses, the reaction temperature drops and the reaction will eventually stop unless heat is supplied.

[0034] In the present invention, when 12 to 16% by volume of oxygen is added, the heat generated by the two oxidation reactions of the following formulas (2) and (3) can cover the heat absorbed by the ammonia decomposition reaction, thereby achieving a high decomposition rate. NH3 + 0.25O2 → H2 + 0.5N2 + 0.5H2O Heat generation △H = -75kJ / mol … (2) H2+0.5O2→H2O Heat generation △H =-284kJ / mol …(3)

[0035] As described above, the conversion rate increases with increasing reaction temperature (the larger the amount of oxygen added) and the amount of catalyst, but if the amount of oxygen added is too much, ammonia and the generated hydrogen will be oxidized (consumed) by the oxygen, so there is an upper limit, which is set to, for example, 20% by volume relative to the amount of ammonia (NH3) supplied. On the other hand, if the amount is too little, the increase in reaction temperature due to heat generation is small, and the reaction (decomposition rate) will not proceed below the temperature due to the ammonia decomposition reaction, so there is a lower limit, which is set to, for example, 3% by volume relative to the amount of ammonia (NH3) supplied.

[0036] As the reforming catalyst in the reforming reactor 1015, it is preferable to use a known NH3·ATR catalyst and a known NH3 decomposition catalyst, either alone or in combination. When these are used in combination, the ratio of the "NH3·ATR catalyst" to the "NH3 decomposition catalyst" is preferably 1:0 to 1:10, more preferably 1:2 to 1:6.

[0037] When combining the optimal catalyst for the ammonia decomposition formula (1) and ammonia oxidation formula (2) + (3) as described above, the oxidation reaction has a fast reaction rate and therefore proceeds 100% in 20-30% of the entire catalyst layer, whereas the decomposition reaction has a slower reaction rate than the oxidation reaction and the reaction temperature drops as the reaction progresses, requiring a large amount of catalyst.

[0038] Therefore, it is preferable to divide the optimal catalyst for each reaction in the amount required for the above reactions in a ratio of 1:2 to 1:6. Also, some catalysts are suitable for both reactions, and in such cases, one type of catalyst (1:0) may be used.

[0039] The ATR catalyst is preferably a catalyst made of one or more of ruthenium (Ru), platinum (Pt), nickel (Ni), cobalt (Co), iron (Fe), manganese (Mn), and molybdenum (Mo), but the present invention is not limited to this.

[0040] The NH3 decomposition catalyst is preferably a catalyst consisting of one or more of ruthenium (Ru), nickel (Ni), cobalt (Co), iron (Fe), manganese (Mn), and molybdenum (Mo), but the present invention is not limited to this.

[0041] The reaction temperature in the reforming reactor 1015 is, for example, 150 to 850°C, preferably 300 to 700°C, and the pressure is 0.03 to 0.9 MPa, preferably 0.07 to 0.7 MPa. The reason for specifying the temperature and pressure within the predetermined ranges is to allow the reforming reaction to proceed efficiently.

[0042] The reaction depends on the performance of the catalyst, but for example, it starts at 150 to 200°C, and the reaction rate increases with the reaction temperature. For example, if the temperature exceeds 650 to 700°C, the activity of the catalyst may decrease (for example, the aggregation of active metals due to heat may be promoted, reducing the active surface area). Therefore, the reaction temperature is preferably in the range of 150 to 850°C.

[0043] Furthermore, high temperatures can cause nitriding of the reaction tube material, which is undesirable for both the catalyst and the reaction tube. Lower pressures are more favorable for hydrogen production in terms of chemical equilibrium, but considering the supply pressure to downstream combustion equipment and pressure losses due to catalyst layers, a pressure of 0.03 to 0.9 MPa is preferable. However, when using a honeycomb catalyst (which has low pressure loss) or depending on downstream equipment, a low pressure of 0.07 MPa may be more favorable for the reaction.

[0044] This ammonia-hydrogen mixed fuel production device can be used to supply the fuel to downstream devices such as engines, boilers, and heating furnaces, or it can be mixed with the raw material ammonia (NH3) to create a fuel supply system.

[0045] Here, the gas component analyzer 17 can measure either or both of the hydrogen concentration and the ammonia concentration, but in this embodiment, hydrogen measurement will be described as an example below.

[0046] That is, in response to the demand for fuel 1018 (NH3 / H2 composition, flow rate) from the demand section X, such as an engine, boiler, or heating furnace, located downstream, a gas component analyzer (hydrogen detector) 1017 installed downstream of the reforming reactor 15 detects the hydrogen (H2) concentration in the reformed gas 1016, and controls the amount of oxygen supplied from the oxygen separation device 1013 so as to satisfy the required H2 concentration (NH3 decomposition rate).

[0047] The decomposition rate of ammonia (NH3) increases with the amount of oxygen (O2) added to the raw ammonia (NH3). In other words, by adding 0 to 16 vol% of oxygen (O2) to the ammonia (NH3) raw material, it can be controlled in the range of 0 to 100 vol%. NH3 → 0.5N2 + 1.5H2…(4) <endothermic reaction> 2NH3+O2→N2+H2+2H2O→NH3+0.25O2 →H2+0.5N2+0.5H2O…(5) <Exothermic reaction> H2+0.5O2→H2O …(6) <exothermic reaction>

[0048] The heat generated by the oxidation reactions of NH3 and H2 in the above-mentioned formulas (5) and (6) is used to promote the endothermic NH3 decomposition reaction in formula (4). As a result, using ammonia as a raw material, it will be possible to freely control the supply amount of the product ammonia (NH3) / hydrogen (H2) mixed gas and its hydrogen (H2) concentration according to demand.

[0049] As described above, according to the present invention, in a small- to medium-scale hydrogen (H2) production system that produces hydrogen (H2) from ammonia (NH3), it is possible to adjust the ammonia (NH3) / hydrogen (H2) composition ratio of the fuel (a composition ratio that can be combusted by, for example, a combustion appliance on the fuel demand section X side) as required, depending on the purpose and demand, for use as a fuel supply to engines, boilers, heating furnaces, etc.

[0050] (Test example) Test examples according to the first embodiment will be described below, but the present invention is not limited to these. Ammonia (NH3) and oxygen (O2) were supplied to the reforming reactor 1015, which was filled with 22 L of catalyst (commercially available ruthenium (Ru)-based catalyst), under the following reaction conditions, and H2 / NH3 mixed gas fuel was produced under the following conditions. Here, an air separation PSA was used as the oxygen separation device 13, and air 11 was supplied and oxygen (O2) separated to a concentration of 90% was used.

[0051] The test conditions at this time were as follows: Pressure: 0.1 MPa Inlet temperature: 230℃ NH3 flow rate: 280Nm 3 / hr O2 flow rate: 42Nm 3 / hr(N2 containing flow rate: 4.6Nm 3 / hr)

[0052] For a hydrogen (H2) concentration of 95 vol% (based on a mixed gas of H2 and NH3), the composition of the mixed gas obtained under the above operating conditions, with 15 vol% oxygen (O2) added to ammonia (NH3), is as follows: H2 / NH3 / N2=67.8 / 3 / 29.2 vol ratio This means that the hydrogen (H2) concentration in the H2 / NH3 mixed gas is 95.8%.

[0053] In contrast, when the demand for hydrogen (H2) concentration on the demand side X changed from 95% to 50%, the hydrogen (H2) concentration of the generated gas was detected by the H2 detector, which is the gas component analyzer 1017, and the oxygen (O2) supply amount was controlled so that the target concentration was reached. As a result, gas that met the demand was obtained when the oxygen (O2) was 10 vol% relative to the ammonia (NH3). H2 / NH3 / N2=42 / 19.9 / 38.1 vol ratio This means that the hydrogen (H2) concentration in the H2 / NH3 mixed gas is 52.3%.

[0054] [Second embodiment] Figure 2 is a schematic diagram of the ammonia-hydrogen mixed fuel production equipment. The same components as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted. As shown in Fig. 2, the ammonia-hydrogen mixed fuel production apparatus 1010B of this embodiment is provided with a bypass line L4 for directly supplying ammonia (NH3) as a raw material from a raw material supply unit 14 to a reformed gas discharge line L2 for discharging a reformed gas 1016 from a reforming reactor 1015. Here, this bypass line L4 has an ammonia introduction position B between the reforming reactor 15 and a measurement point A of a gas component analyzer 17 on the downstream side of the reforming reactor 15. In Fig. 2, the symbol L 11 is the first signal line, and V1 is the first on-off valve.

[0055] In this way, by installing the bypass line L4, when the demand for hydrogen (H2) concentration in the gas of the fuel 18 from the demand unit X side is low or when it is necessary to quickly respond to a request to reduce the hydrogen (H2) concentration from a high concentration (e.g., 100 Vol%) to a low concentration (e.g., 30 Vol%), the gas component analyzer 17 sends a first signal S1 to the first on-off valve V1, opens the first on-off valve V1, and causes ammonia (NH3) from the raw material supply unit 14 to bypass the reforming reactor 15 via the bypass line L4, and supplies the ammonia directly before the hydrogen detector which is the gas component analyzer 17, making it possible to quickly adjust the concentration to the required low concentration (e.g., 30 Vol%).

[0056] [Third embodiment] Figure 3 is a schematic diagram of an ammonia-hydrogen mixed fuel production apparatus. The same components as those in the first and second embodiments are denoted by the same reference numerals and the description thereof will be omitted. As shown in Fig. 3, the ammonia-hydrogen mixed fuel production apparatus 1010C of this embodiment is provided with a reservoir 1021 for temporarily storing the reformed gas 1016 in a reformed gas discharge line L2 for discharging the reformed gas 1016 from the reforming reactor 1015. 12 is a second signal line, and V2 is a second on-off valve. The reservoir 1021 is designed to store the reformed gas 16 at a constant concentration.

[0057] In this embodiment, by installing the bypass line L4 and the storage tank 1021, when the required hydrogen (H2) concentration in the fuel 1018 gas is low or when it is necessary to quickly respond to a request to reduce the hydrogen (H2) concentration from a high concentration (for example, 100 Vol%) to a low concentration (for example, 30 Vol%), the gas component analyzer 1017 sends a first signal S1 to the first on-off valve V1, and ammonia from the raw material supply unit 1014 that adjusts the first on-off valve V1 bypasses the reforming reactor 15 via the bypass line L4, and the ammonia is supplied directly before the gas component analyzer 1017, thereby making it possible to quickly adjust the composition of the adjusted gas 16A to the required concentration (low concentration (for example, 30 Vol%)).

[0058] At this time, the gas component analyzer 1017 may send a second signal S2 to the second on-off valve V2 to adjust the second on-off valve V2, thereby adjusting the supply ratio of the reformed gas 1016 to produce the adjusted gas 16A.

[0059] This allows the gas composition of the reformed gas and ammonia to be adjusted (for example, from 30 / 70 to, for example, 20 / 80) according to the composition of ammonia and hydrogen measured by the gas component analyzer 1017 (for example, 30 / 70).

[0060] [Fourth embodiment] Figure 4 is a schematic diagram of an ammonia-hydrogen mixed fuel production apparatus. The same components as those in the first to third embodiments are denoted by the same reference numerals and the description thereof will be omitted. In the first to third embodiments, the oxygen separation device 13A is used for explanation, but in the present invention, the oxygen supply unit that supplies oxygen is not limited to this, and it is also possible to use, for example, an air dryer 1013B that removes moisture from the supplied air. As shown in Fig. 4, the ammonia-hydrogen mixed fuel production apparatus 10D of this embodiment is equipped with an air dryer 1013B that removes moisture from air 1011 supplied by, for example, an air compressor. The oxygen supply unit of this embodiment is composed of an air compressor (not shown) that supplies air, and the air dryer 1013B installed in the subsequent stage. Here, this air dryer 1013B can be either an adsorption method or a cooling method.

[0061] This air dryer 1013B removes moisture from the air and prevents water from poisoning a catalyst such as platinum (Pt) used in the reforming reactor 1015. The adsorption method is a method of removing moisture using, for example, zeolite.

[0062] The cooling method can remove moisture by adjusting the saturated vapor pressure corresponding to the cooling temperature (for example, by cooling to 20°C or below). The cooling temperature is preferably 20°C or below, and more preferably -20°C or below.

[0063] According to this embodiment, when oxygen is supplied from the air, moisture in the air is removed, thereby preventing, for example, a platinum (Pt) catalyst used in the reforming reactor 1015 from being poisoned.

[0064] [Fifth embodiment] Next, specific variations of the reforming reactor in the first to fourth embodiments will be described. 5 is a cross-sectional view showing the internal structure of a reactor 10 according to a fifth embodiment. The reactor 10A is a reactor that performs autothermal reforming (ATR) of ammonia. The reactor 10 includes a first catalyst section 13 and a second catalyst section 21.

[0065] In the reactor 10A, heat is generated in the first catalyst section 13 by combustion of a combustible gas such as hydrogen. The gas G2 having the generated heat flows into the second catalyst section 21, heating the second catalyst section 21. In the second catalyst section 21, the reaction heat of the ammonia decomposition reaction (endothermic reaction) is supplied by utilizing the heat generated by the partial oxidation reaction (exothermic reaction) of ammonia using oxygen. Therefore, the reactor 10A is thermally self-sustaining without the need for an external heat source (such as a heating furnace), and can decompose ammonia (produce hydrogen) with an efficient and simple reactor configuration.

[0066] The reactor 10A has a configuration that can generate a reaction for heating the second catalyst section 21 used for ammonia reforming before the ammonia reforming. This reaction proceeds inside the reactor 10A, and there is no need to provide a heat source outside the reactor 10A to supply heat to the inside of the reactor 10A. With this configuration, the reactor 10A can be started up quickly when ammonia reforming is performed, and the time required for starting reforming and changing the load can be shortened.

[0067] The reactor 10A includes a housing 1, which includes an inlet 2 and an outlet 3. The housing 1 has a cylindrical shape that is circular when viewed from above, but may also have a rectangular shape when viewed from above. The cross-sectional areas of the inlet 2 and a flow path 11 formed therein are different, and the inlet 2 and the outlet 3 are narrower than the internal flow path 11 (the portion with a locally expanded cross-sectional area). The flow path 11 is formed between the inlet 2 and the outlet 3. Gas G (gases G1, G2, and G3) flows through the flow path 11, as will be described in detail later.

[0068] Flow path 11 is defined by heat insulating material 12 arranged along the inner wall of housing 1. Housing 1 is not completely cylindrical, but has a shape that locally narrows inside near inlet 2. Furthermore, near outlet 3, housing 1 has a shape that narrows toward outlet 3. Of flow path 11 formed by being surrounded by heat insulating material 12, the shape between inlet 2 and the upper end of the locally widened portion formed below inlet 2 is cylindrical (circular in top view). However, the shape between the inlet 2 and the upper end of the locally widened portion formed below the inlet 2 may be a square tube (rectangular in top view).

[0069] The inlet 2 is an opening for introducing the gas G1 into the inside of the housing 1 (reactor 10A). The gas G1 is a gas containing ammonia and flammable gases other than ammonia. Therefore, ammonia and flammable gases other than ammonia are introduced into the inside of the housing 1 through the inlet 2. Hereinafter, the term "flammable gas" refers to flammable gases excluding ammonia. The definition and examples of flammable gases will be described later.

[0070] It is not necessary for ammonia and the combustible gas to be supplied simultaneously in a mixed state. Therefore, for example, ammonia and the combustible gas are introduced into the reactor 10 through the inlet 2, either together or independently. The combustible gas may be, for example, hydrogen. The gas G1 may also contain components used in the combustion of the combustible gas and the ammonia reforming, such as oxygen. The gas G1 may also contain gases other than ammonia, the combustible gas, and oxygen. The gas G1 introduced into the housing 1 is supplied to the first catalyst section 13. The gas G1 introduced into the first catalyst section 13 generates the gas G2 by catalytic reaction.

[0071] Gas G2 flows out from the first catalytic section 13 and flows into the second catalytic section 21. Gas G2 contains ammonia heated by heat generated by the combustion of the combustible gas in gas G1 and oxygen not used in the first catalytic section 13. Gas G2 may also contain unburned combustible gas.

[0072] Gas G3 generated by the catalytic reaction flows out from the second catalyst section 21, and the gas G3 flows out from the outlet 3. The outlet 3 is an opening that allows the gas G3 to flow out from the inside of the housing 1 (reactor 10). The gas G3 is, for example, hydrogen generated in the reactor 10, nitrogen generated in association with the hydrogen, unreacted gas or accompanying gas of the introduced gas G1, etc. Hereinafter, the gases G1, G2, and G3 will be collectively referred to as gas G.

[0073] The reactor 10 can be operated at a rate of, for example, 100 m per hour. 3 ~2,000m 3 The reactor 10 has a small to medium size capable of generating hydrogen of 1000 kJ / s. The gas hourly space velocity (GHSV) of the gas G that can flow through the inside of the reactor 10 is, for example, 3,000 / hr or more and 50,000 / hr or less, preferably 5,000 / hr or more and 30,000 / hr or less. Therefore, the size of the reactor 10 can be set, for example, such that if the housing 1 has a cylindrical (approximately cylindrical) shape, the diameter of the housing 1 can be set to 300 mm or more and 800 mm or less. Furthermore, if the housing 1 is a square housing having a rectangular shape when viewed from above, both the width and depth of the housing 1 can be set to 300 mm or more and 800 mm or less.

[0074] As in the present disclosure, if the diameter, width, and depth are less than 1 m, for example, the outer surface area of ​​the casing 1 per unit volume of the first catalytic section 13 and the second catalytic section 21 increases, making heat radiation more likely to occur outside the walls of the reactor 10A. Furthermore, if the diameter, width, and depth of the casing 1 are increased to suppress heat radiation, the height of the casing 1 decreases. This reduces the flow rate of the gas G, which may result in the gas G not dispersing uniformly inside the casing 1 or making it difficult for the gas G to diffuse into the catalyst. Therefore, in the example of the present disclosure, the reactor 10A is made compact and is sufficiently insulated from the first catalytic section 13 and the second catalytic section 21. This minimizes the radiation of heat generated by the combustion of the combustible gas and the oxidation of ammonia from the outer walls of the reactor 10A, thereby covering the heat absorbed by the ammonia decomposition reaction and achieving high hydrogen yield and thermal efficiency.

[0075] The first catalytic section 13 is disposed inside the housing 1, between the inlet 2 and the second catalytic section 21. By disposing the first catalytic section 13 in this position, the second catalytic section 21 can be heated by the heat generated by the catalytic reaction of the first catalytic section 13, and this heating allows ammonia to be reformed in the second catalytic section 21. This shortens the time until ammonia reforming (start-up time).

[0076] The first catalyst section 13 and the second catalyst section 21 are provided in a flow path 11 inside the housing 1. The first catalyst section 13 is provided on the upstream side of the gas flow in the flow path 11, and the second catalyst section 21 is provided on the downstream side of the gas flow in the flow path 11. Therefore, the gas G2 flowing out from the first catalyst section 13 flows into the second catalyst section 21.

[0077] The first catalyst section 13 includes a first catalyst. The first catalyst generates heat by burning (oxidizing) the combustible gas in the gas G1 introduced from the inlet 2. In the example of the present disclosure, the combustible gas is introduced from the inlet 2 together with ammonia. However, the combustible gas may be introduced from the inlet 2 separately from the ammonia. In the example of the present disclosure, first, the gas G1 containing ammonia and the combustible gas is introduced from the inlet 2, and the combustible gas is, for example, selectively combusted in the first catalyst section 13. As a result, the reaction gas containing ammonia is heated by the heat generated by the combustion of the combustible gas, and the reaction gas acts as a heat medium to heat the second catalyst section 21 in the subsequent stage.

[0078] In the first catalyst section 13, it is preferable that no ammonia is burned or only a very small amount of ammonia is burned due to the selective combustion of the combustible gas as described above. Therefore, for example, the combustible gas can be selectively burned by using a catalyst that can selectively burn the combustible gas or by setting the temperature (for example, 80°C or lower) at which the combustible gas can be selectively ignited (combusted).

[0079] The type of flammable gas is not particularly limited as long as it is a gas other than ammonia and is easily combustible at room temperature (e.g., 30° C.). Examples include flammable gases specified in the Container Safety Regulations (Ministry of International Trade and Industry Ordinance No. 50 of 1966), which is a Japanese law, as well as at least one type of alcohol gas (vapor) such as methanol, ethanol, or propanol.

[0080] In the example of the present disclosure, the first catalyst provided in the first catalyst section 13 is platinum, and the combustible gas is hydrogen. Therefore, the reaction shown in the following thermochemical reaction formula (11) proceeds. H2 + 1 / 2O2 → H2O Heat generation △H = -284 kJ / mol … (11)

[0081] The heat generated by combustion in the first catalyst part 13 is heat generated by the combustion of the combustible gas. Therefore, the amount of heat generated can be controlled by the amount of combustible gas burned, i.e., the amount of combustible gas in the gas G1. Therefore, by providing the first catalyst part 13 that burns the combustible gas, the amount of heat generated can be controlled and the heating temperature of the housing 1 can be suppressed.

[0082] The first catalyst section 13 is configured by disposing (filling) a particulate first catalyst on, for example, a porous plate. The particle diameter of the first catalyst is, for example, 1 mmφ or more and 10 mmφ or less.

[0083] Fig. 6 is a perspective view of the first catalyst section 13 and is a diagram illustrating the size of the first catalyst section 13. Fig. 6 also illustrates the heat insulating material 12 surrounding the first catalyst section 13. For convenience, Fig. 6 shows the shape of the heat insulating material 12 as rectangular, but this is not limited thereto. The first catalyst portion 13 is cubic or rectangular parallelepiped (square) in shape, and has a width W1, a depth D1, and a height H1. When the first catalyst portion 13 is particulate, the width W1, depth D1, and height H1 of the entire particles when the particles are arranged (packed) in a square shape are specified. When the first catalyst portion 13 is a honeycomb catalyst, the distance between opposing outer surfaces of the honeycomb catalyst is the width W1, depth D1, and height H1.

[0084] H1 / W1 is, for example, 0.1 or more and 1.0 or less, preferably 0.3 or more and 0.7 or less. W1 / D1 is, for example, 0.5 or more and 2 or less, preferably 0.9 or more and 1.1 or less, and more preferably 1. The thickness T1 of the heat insulating material 12 at the portion surrounding the first catalyst section 13 is, for example, 50 mm or more and 300 mm or less, preferably 100 mm or more and 200 mm or less.

[0085] Returning to FIG. 5 , the inner wall of the housing 1 is provided with a heat insulating material 12. Different heat insulating materials may be used for the heat insulating material 12 near the inlet 2 and outlet 3 and for the portion housing the first catalyst section 13 and the second catalyst section 21. The heat insulating material 12 is made of a material that is heat resistant and has excellent mechanical strength, and has some flexibility (elasticity). Therefore, although the heat insulating material 12 and the heat insulating material 14 are made of different materials in the example of the present disclosure, they may be made of the same material by adjusting the shape, for example. The heat insulating material 12 is made of, for example, a heat-resistant material having a filamentous or fibrous shape, specifically, for example, ceramic fiber or cement castable, but is not limited thereto. The flexibility (elasticity) of the heat insulating material 12 in this embodiment is not as great as that of the heat insulating material 14 described later with reference to the third embodiment.

[0086] The reactor 10A includes a first distribution section 18A as shown in FIG. 5A and a second distribution section 18B as shown in FIG. 5D. 5A, the first dispersion section 18A is disposed between the first catalyst section 13 and the second catalyst section 21. By disposing the first dispersion section 18A between the first catalyst section 13 and the second catalyst section 21 in this manner, the gas G2 flowing out from the first catalyst section 13 is dispersed toward the second catalyst section 21.

[0087] Furthermore, by providing the first dispersion section 18A between the first catalyst section 13 and the second catalyst section 21 as shown in Figure 5A, it is possible to prevent the heat (gas G2) generated in the first catalyst section 13 from being transmitted only to the area directly below the first catalyst section 13, making it easier for the heat (gas G2) to come into uniform and even contact with the entire second catalyst section 21 located below the first catalyst section 13.

[0088] As shown in Fig. 5A, the first dispersion section 18A of the present disclosure provided between the first catalyst section 13 and the second catalyst section 21 may be configured to blow out the gas G2 obliquely downward from the center of the first catalyst section 13. In this case, the gas G2 may be blown out directly downward in addition to obliquely downward. Alternatively, a porous plate filled with particulate first catalyst 13 may also serve as the first dispersion section 18A. Alternatively, the first dispersion section 18A may be separately and independently installed below the first catalyst 13.

[0089] 5B and 5C are enlarged views of the X portion of the first dispersion portion 18A in FIG. 5A, and show modified examples of the first dispersion portion 18A. In FIG. 5B, pores 18b are uniformly formed in a dispersion plate 18a that constitutes first dispersion section 18A-1.

[0090] 5C, two types of holes (pores 18b-1 and 18b-2) are formed in the dispersion plate 18a constituting the first dispersion section 18A-2, with the small-diameter pores 18b-1 being formed on the central side and the large-diameter pores 18b-2 being formed on the peripheral side of the small-diameter pores 18b-1, thereby adjusting the aperture ratio. This may result in the outflowing gas G2 being discharged more uniformly overall on the peripheral side than on the central side in the horizontal direction in the first dispersion section 18A-2.

[0091] In addition, as shown in FIG. 5D, another example of the second dispersion section 18B can be installed between the inlet 2 and the first catalyst section 13 to disperse the introduced gas G1 toward the first catalyst section 13. In the disclosure shown in FIG. 5D, the first distribution unit 18A is also provided, but if the distribution conditions are good, the first distribution unit 18A may not be provided.

[0092] In addition, the second dispersion section 18B shown in Figure 5D may be provided above the first catalyst section 13 to form a uniform gas flow inside the second dispersion section 18B and minimize the temperature distribution relative to the arranged second catalyst section 21.

[0093] When the second dispersion section 18B is provided between the inlet 2 and the first catalyst section 13, for example, a basket filled with spherical or raschling-shaped filler members may be disposed. Alternatively, a bottomed cylinder having openings on the side or bottom, or a member such as a louver or wind deflector for adjusting the wind direction may be installed.

[0094] Furthermore, as shown in FIG. 5D of the present disclosure, a spherical wire mesh cage 18 filled with alumina balls 18d may be placed at a position where the flow path expands from the inlet 2 of the housing 1 (the bottom of the cage protrudes into the space of the flow path 11), and the rectified gas may pass through a packed bed made of spherical alumina balls 18c, so that the rectified gas is dispersed from the inlet 2 to the expanding part of the reactor.

[0095] The reactor 10A includes a second catalyst section 21. The second catalyst section 21 has a honeycomb shape, and the specific structure of the second catalyst section 21 will be described later with reference to a third embodiment. The second catalyst section 21 is disposed between the first catalyst section 13 and the outlet 3 and includes a second catalyst. The second catalyst is heated by the heat generated in the first catalyst section 13 and generates hydrogen from ammonia contained in the gas G2.

[0096] The second catalyst supported on the second catalyst section 21 is a catalyst that reforms ammonia. Hydrogen is produced from ammonia through reforming. The specific components of the catalyst are not particularly limited as long as the catalyst is capable of reforming ammonia, and it is preferable that the catalyst contains a transition metal such as Ru, Co, Ni, Fe, or Pt as its main component.

[0097] 7 is a perspective view of the second catalyst section 21, and is a diagram illustrating the size of the second catalyst section 21. In FIG. 7, the heat insulating materials 12 and 22 that surround the second catalyst section 21 are also shown.

[0098] The second catalyst section 21 is surrounded by multiple types of heat insulating materials 12, 22. The second catalyst section 21 is cubic or rectangular parallelepiped (rectangular) in shape and has a width W2, a depth D2, and a height H2. H2 / W2 is, for example, 0.5 to 3, and preferably 0.8 to 2. W2 / D2 is, for example, 0.5 to 2, and preferably 0.9 to 1.1, and more preferably 1. The total thickness T2 of the heat insulating materials 12, 22 surrounding the second catalyst section 21 is, for example, 50 mm to 300 mm, and preferably 100 mm to 200 mm.

[0099] In the relationship between the first catalyst portion 13 and the second catalyst portion 21, W2 / W1 is, for example, 1 or more and 5 or less, and preferably 2 or more and 3 or less. The first catalyst portion 13 and the second catalyst portion 21 are both covered on the sides with heat insulating material. The ratio of the thickness T1 of the heat insulating material covering the first catalyst portion 13 to the thickness T2 of the heat insulating material covering the second catalyst portion 21 (T1 / T2) is, for example, 1 or more and 3 or less, and preferably 1 or more and 2 or less.

[0100] Returning to FIG. 5, the reforming in the second catalyst section 21 proceeds mainly through two separate reactions. Specifically, for example, the reactions include partial oxidation of ammonia (reaction formula (12) below), an oxidation reaction of ammonia (reaction formula (13) below), and a decomposition reaction of ammonia (reaction formula (14) below). The reactions of reaction formulas (2) and (13) proceed mainly in the upper part (front stage) of the second catalyst section 21, and the reaction of reaction formula (14) proceeds mainly in the lower part (lower stage) of the second catalyst section 21. However, the reforming does not necessarily proceed in two stages. NH3 + 1 / 4O2 → H2 + 1 / 2N2 + 1 / 2H2O Exothermic reaction △H = -75kJ / mol … (12) NH3 + 3 / 4O2 → 1 / 2N2 + 3 / 2O2 Exothermic reaction △H = -317kJ / mol … (13) NH3→3 / 2H2+1 / 2N2 endotherm=+45.9kJ / mol …(14)

[0101] In particular, hydrogen is produced by the reaction of reaction formula (14), and a hydrogen-containing gas G3 is obtained.

[0102] FIG. 8 is a diagram illustrating the temperature gradient between the second catalyst section 21 and the housing 1. For example, gas G2 at temperature T1 (e.g., approximately 630°C) reaches the second catalyst section 21 (particularly the second flow path 211). As a result of heat conduction within the end 213 of the second catalyst section 21, the temperature of the outer surface of the second catalyst section 21 drops to temperature T2 (e.g., approximately 450°C). Furthermore, heat conduction is further hindered by the insulating material 22 surrounding the second catalyst section 21, and the temperature of the surface of the insulating material 22 opposite the second catalyst section 21 drops to temperature T3 (e.g., approximately 350°C). Finally, heat conduction is also hindered by the insulating materials 12 and 22, and the temperature of the surface of the insulating material 12 and 22 opposite the second catalyst section 21 drops to temperature T4 (e.g., 70°C or less). Finally, slight heat conduction occurs within the housing 1, and the temperature at the outer surface of the housing 1 drops to temperature T5 (e.g., 50°C or less). Therefore, damage (oxidation, corrosion) caused by heat to the material (for example, carbon steel) that constitutes the housing 1 can be suppressed.

[0103] Compared to catalytic cracking, another technology for producing hydrogen from ammonia, ATR allows for a larger GHSV, which is advantageous in terms of hydrogen production. However, the large GHSV results in a large pressure loss in the second catalyst section 21. In addition, the oxidation reaction in the second catalyst section 21 generates a large amount of heat, causing the inside of the reactor 10A to reach a high temperature of 600°C or higher.

[0104] In the ammonia decomposition reaction, lower pressure and higher temperature are advantageous from the standpoint of chemical equilibrium, as the reaction shifts toward the product (hydrogen). However, a large pressure loss requires a high inlet pressure for the reactor 10, which is disadvantageous in terms of both chemical equilibrium and the compression energy of the gas G1 (raw material gas). However, a high temperature is advantageous in terms of chemical equilibrium. However, a high temperature causes the reactor 10A (especially the housing 1) to be used in a temperature range where nitridation is likely to occur. Specifically, for example, at an internal temperature range of 500°C to 700°C, the nitrogen generated by the decomposition of ammonia promotes nitridation of iron, cobalt, molybdenum, etc., making the structures constituting the reactor 10 brittle. For this reason, it is necessary to use high-quality materials that are as resistant to nitridation as possible (e.g., "Inconel 600" (registered trademark)) and keep the internal temperature of the reactor 10 low. This increases the cost of hydrogen production and hinders the progress of the ammonia decomposition reaction.

[0105] Therefore, in the reactor 10A of the present disclosure, in order to suppress heat radiation to the outside of the reactor 10 and to lower the temperature of the structures constituting the reactor 10 to a temperature lower than the nitriding temperature of approximately 600°C (for example, 450°C or lower), the side surfaces of the first catalyst section 13 are wrapped (covered) with a heat insulating material 12, and the side surfaces of the second catalyst section 21 are wrapped (covered) with heat insulating materials 12 and 22. This suppresses heat radiation through the side surfaces of the first catalyst section 13 and the second catalyst section 21, and makes it possible to lower the surface temperature (external temperature) of the reactor 10 to a temperature lower than the nitriding temperature (for example, 80°C or lower).

[0106] FIG. 9 is a diagram showing a structure for starting up the reactor 10A using at least a portion of the hydrogen produced in the second catalyst section 21. The reactor 10A includes a heat exchanger 51, a tank 52, a pump 53, an outlet flow path 54, and a return flow path 54b. The tank 52 stores hydrogen produced in the second catalyst section 21 and discharged from the outlet 3. The hydrogen discharged from the outlet 3 is cooled to, for example, 40°C or less by cooling water CW in the heat exchanger 51 and flows into the tank 52. The tank 52 is provided in the outlet flow path 54 and stores the discharged hydrogen. The outlet flow path 54 discharges hydrogen from the outlet 3 and is, for example, a pipe. The return flow path 54b branches from a branching point 54a of the outlet flow path 54 and returns hydrogen to the inlet 2 and is, for example, a pipe. The hydrogen in the tank 52 is returned to the inlet 2 by the operation of the pump 53. The return flow path 54b is provided with a valve 54c for regulating the flow rate of hydrogen. The hydrogen from the outlet passage 54 is used as a product.

[0107] The initial start-up of the reactor 10A is performed using a combustible gas (e.g., hydrogen in a hydrogen cylinder) stored in a separately installed cylinder or the like. As the reforming progresses, hydrogen is generated in the second catalyst section 21 as shown in reaction formula (4), and the generated hydrogen is stored in the tank 52. When the reactor 10A is started up, some or all of the hydrogen stored in the tank 52 is used as the combustible gas. This eliminates the need for a cylinder or the like when starting up the reactor 10A for the second time or thereafter.

[0108] Fig. 10 is a graph showing an example of the temperature distribution inside the reactor 10 when combustible gas is combusted in the first catalytic section 13 under specific reaction conditions in the first embodiment. The graph shown in Fig. 10 shows the temperature distribution at the start of the reactor 10 for ammonia reforming. The horizontal axis represents the height position (cm) from the upper end of the first catalytic section 13 toward the second catalytic section 21 (downstream in the gas flow), and the vertical axis represents the temperature. For reference, the first catalytic section 13 and the second catalytic section 21 are shown at corresponding positions among the height positions shown on the horizontal axis of Fig. 10.

[0109] Reaction conditions: 300Nm 3In the reactor 10 that produces hydrogen at 1000kJ / hr, an alumina catalyst (3 mm diameter spheres) carrying 2 wt% platinum was used as the first catalyst section 13. A honeycomb catalyst (W1 = 150 mm, D1 = 150 mm, H1 = 50 mm) carrying cobalt was used as the second catalyst section 21. The width ratio: W2 / W1 was 1, and the thickness ratio of the heat insulating material: T1 / T2 was 1. The first catalyst section 13 was disposed between the inlet 2 and the second catalyst section 21 in a portion having the same cross-sectional area as the second catalyst section 21. Specifically, the horizontal cross-sectional areas of both the first catalyst section 13 and the second catalyst section 21 were 300 mm x 300 mm = 90,000 mm. 2 The amount of the first catalyst packed was 3 L, and the amount of the second catalyst packed was 40.5 L.

[0110] After hydrogen reduction at 600 °C, the flow rates of ammonia and oxygen in gas G1 were set to 250 Nm 3 / hr, 40Nm 3 / hr, plus 10Nm of hydrogen 3 / hr was added and supplied to the first catalyst section 13 (startup of the reactor 10). The temperature distribution in the first catalyst section 13 and the second catalyst section 21 at this time is shown in FIG.

[0111] When gas G1 is introduced and ignited in first catalytic section 13, the heat of combustion of hydrogen causes a rapid rise in the temperature in first catalytic section 13. The temperature near the outlet of first catalytic section 13 then reaches a temperature of, for example, about 180°C to 300°C, at which the partial oxidation reaction of ammonia (the reaction represented by reaction formula (2)) that proceeds near the inlet of second catalytic section 21 in the subsequent stage can proceed.

[0112] The interior of reactor 10B is insulated by heat insulating materials 12, 22, etc. For example, the second catalyst section 21 is heated by the inflow of gas G2, which has reached approximately 200°C or higher. At the same time, the partial oxidation reaction and oxidation reaction of ammonia, as shown in reaction formulas (2) and (3), proceed near the inlet of second catalyst section 21. Because these are exothermic reactions, the temperature of gas G flowing through second catalyst section 21 further increases, and the temperature of gas G increases to, for example, 600°C or higher. However, toward the downstream side of second catalyst section 21, the ammonia decomposition reaction (hydrogen production reaction), as shown in reaction formula (4), becomes dominant. Therefore, the temperature of gas G flowing through second catalyst section 21 begins to decrease.

[0113] Fig. 11 is a graph showing the temperature distribution inside the reactor 10 when ammonia reforming is performed in the reactor 10A without adding a combustible gas. The graph shown in Fig. 11 is a graph when ammonia reforming is performed using the second catalyst part 21 that has already been heated as shown in the graph of Fig. 10.

[0114] The temperature of the second catalyst section 21 is already about 600°C to 700°C in an adiabatic state. For this reason, when gas G1 containing, for example, ammonia (but not hydrogen) and at about 30°C (room temperature) is introduced, the gas G1 passes through the first catalyst section 13 without igniting and flows into the second catalyst section 21 as gas G2. The gas G (gas G1) that has flowed into the second catalyst section 21 undergoes a reaction in the second catalyst section 21, which has been heated to about 600°C to 700°C.

[0115] For example, when gas G2 at about 30°C flows into the second catalytic section 21, the temperature near the inlet of the second catalytic section 21 may drop. However, the reaction that proceeds near the inlet of the second catalytic section 21 (the reaction shown in reaction formulas (12) and (13)) is an exothermic reaction. Therefore, even if a relatively low-temperature gas G2 flows in, the temperature of the second catalytic section 21 hardly drops. Therefore, the temperature of the second catalytic section 21 is maintained high in an adiabatic state, and the ammonia decomposition reaction continues as shown in FIG. 11 even without the addition of a flammable gas.

[0116] Fig. 12 is a flowchart showing a method for producing hydrogen (hereinafter referred to as the production method of the present disclosure). The production method shown in Fig. 12 can be carried out using, for example, reactor 10 (Fig. 5). Therefore, Fig. 12 will be described with reference to Fig. 5 as appropriate. For convenience, Fig. 12 exemplifies hydrogen as the combustible gas. The manufacturing method of the present disclosure is also a method for reforming ammonia and includes steps S1 to S4. As shown in Fig. 12, step S1 (introduction step) is a step of introducing a gas G1 (introducing gas) containing ammonia and a combustible gas other than ammonia into reactor 10A. This causes hydrogen to burn in first catalyst section 13, and heats second catalyst section 21. The amount of combustible gas added to ammonia is not particularly limited, but is, for example, 0.02 to 0.06 moles, preferably 0.03 to 0.05 moles, of the combustible gas (such as hydrogen) per mole of ammonia.

[0117] Step S2 (heating step, combustion step) is a step in which combustible gas in the introduced gas G1 is selectively combusted by the first catalyst. Combustion can be performed, for example, by igniting the gas G1 in the first catalyst section 13. Also, selective combustion of the combustible gas can be performed, for example, by setting the temperature of the gas G1 to a temperature equal to or higher than the ignition temperature of the combustible gas and lower than the ignition temperature of ammonia.

[0118] Step S2 (heating step, combustion step) is a step of further heating the second catalytic section 21 (an example of a second catalyst) by, for example, heat generated by burning the combustible gas in the first catalytic section 13. As described above, the second catalytic section 21 is a catalytic section that generates hydrogen from ammonia. By heating the second catalytic section 21, the temperature of the second catalytic section 21 is raised to a predetermined temperature. The predetermined temperature is not particularly limited, but is preferably a temperature at which the reactions of the above reaction formulas (12) to (14) can proceed. Furthermore, raising the temperature to the predetermined temperature can be carried out as appropriate by adjusting the concentration of the combustible gas in the gas G1.

[0119] Step S3 (reforming step) is a step of stopping the introduction of the combustible gas (hydrogen) after the temperature of the second catalyst section 21 (an example of the second catalyst) reaches a predetermined temperature. Since the introduction is stopped, the combustible gas (hydrogen) is no longer supplied to the first catalyst section 13, and therefore combustion of the combustible gas (hydrogen) in the first catalyst section 13 stops.

[0120] Step S4 (reforming step) is a step of generating hydrogen from ammonia using the second catalyst section 21. The introduction of the combustible gas (hydrogen) can be stopped while continuing the introduction of the gas G1 containing ammonia. However, the introduction of the combustible gas may also be stopped by stopping the introduction of the gas G1 containing ammonia and the combustible gas (hydrogen), and then introducing the gas G1 containing ammonia but not the combustible gas (hydrogen).

[0121] When the introduction of the combustible gas is stopped, the gas G1 containing ammonia and oxygen does not react in the first catalyst section 13 and is supplied as gas G2 to the second catalyst section 21. Immediately after the introduction of the combustible gas is stopped, the gas G2 contains products produced by the combustion of the combustible gas in the first catalyst section 13. When the combustible gas is hydrogen, for example, the products are water.

[0122] The reaction pressure in the second catalytic section 21 (particularly the pressure at which the reactions of reaction formulas (2) and (3) proceed) is, for example, 0.02 MPaG to 0.6 MPaG, preferably 0.05 MPaG to 0.3 MPaG. The reaction temperature is, for example, 180°C to 800°C, preferably 200°C to 650°C. The oxygen content in the gas G2 supplied to the second catalytic section 21 is, for example, 0.1 mol to 0.2 mol, preferably 0.12 mol to 0.16 mol per mol of ammonia. Oxygen is also consumed in the first catalytic section 13 installed in the upstream of the second catalytic section 21. Therefore, the first catalytic section 13 and It is preferable to determine the amount of oxygen in the gas G1 introduced into the reactor 10, taking into consideration the amounts of oxygen consumed in both the first catalyst section and the second catalyst section 21.

[0123] The above points can be summarized as follows: In the present disclosure, combustible gas (hydrogen) is combusted in the first catalytic section 13. This causes the temperature of the second catalytic section 21 to rise to a temperature at which the oxidation reaction of ammonia can be initiated. Then, hydrogen is produced by the oxidative decomposition of ammonia in the second catalytic section 21.

[0124] In boilers and heating furnaces, which are frequently started and stopped, the reaction gas must be preheated to 200°C or higher before each start-up. Conventionally, a heater (e.g., an electric heater or burner) was required for this heating, and it took time to heat up the gas. Therefore, in the present disclosure, when a combustible gas such as hydrogen and oxygen are added to gas G1 (reaction gas), a combustion reaction proceeds in the first catalyst section 13 from room temperature (e.g., 30°C). This heat generation raises the temperature of gas G1 in the reactor 10 to a temperature at which the oxidation reaction of ammonia begins in the second catalyst section 21 downstream. This eliminates the need for a heating furnace and allows for a faster temperature rise response. This is because the reaction gas can be heated directly, rather than indirectly from the outside.

[0125] In addition, in the present disclosure, the second catalyst part 21 is a honeycomb catalyst having a honeycomb shape, which improves the insulating properties of the second catalyst part 21 and the housing 1, thereby suppressing the dissipation of heat generated by the combustion of combustible gas in the first catalyst part 13 and the heat generated by the oxidation of ammonia in the second catalyst part 21.

[0126] The main subject of this disclosure is "hydrogen production capacity of 10 Nm 3 / hr~2,000Nm 3 In a small-to-medium-sized reactor of 1 / hr, the ratio of the reactor outer surface area to the catalyst unit volume is large. This makes it easy for heat to be released, lowering the temperature of the gas G, and as a result, lowering the ammonia decomposition rate. On the other hand, if the heat insulating material 12 is made thicker, the outer diameter of the reactor 10 increases, which hinders the compactness of the small-scale device. Alternatively, a large amount of oxygen must be supplied to maintain the temperature equivalent to the heat released, which reduces the hydrogen yield. Therefore, in the present disclosure, a honeycomb catalyst is used. With a honeycomb catalyst, no reaction occurs on the outer surface of the honeycomb, so the reaction does not occur on the inner surface of the reactor 10 (the insulating material No heat is generated on the surface in contact with the catalyst (surface 12), and because the outer wall of the honeycomb is ceramic, the catalyst itself has excellent heat insulation. This allows for both compactness and improved hydrogen yield.

[0127] Furthermore, in the present disclosure, the first catalyst section 13 and the second catalyst section 21 are arranged in a portion having the same cross-sectional area (a locally expanding portion inside the housing 1). This makes it possible to suppress heat dissipation. Furthermore, as will be described in detail later with reference to the second embodiment, the first catalyst section 13 is arranged between the inlet 2 and the upper end of the locally expanding portion formed below the inlet 2. This allows The thickness T1 of the heat insulating material 12 covering the first catalyst portion 13 can be increased, and heat radiation from the first catalyst portion 13 can be significantly suppressed.

[0128] In addition, in the present disclosure, the sizes of the first catalytic section 13 and the second catalytic section 21 are set as described above. Producing hydrogen from ammonia to achieve carbon neutrality requires high thermal efficiency during the production process. Therefore, the reactor 10A must have high insulation, low pressure loss, and a high one-pass conversion rate. To reduce pressure loss and improve insulation, H1 / (W1×D1) and H2 / (W2×D2) should be small. However, if these values ​​are too small, the flow rate of gas G decreases, making it difficult for gas G to diffuse into the first catalytic section 13 and the second catalytic section 21, resulting in a decrease in the ammonia conversion rate. Furthermore, the uniformity of the gas G distribution is impaired, resulting in uneven flow and a decrease in the ammonia decomposition rate. Therefore, in the present disclosure, the sizes of the first catalytic section 13 and the second catalytic section 21 are optimized and set as described above, thereby improving the ammonia decomposition efficiency.

[0129] According to this embodiment, it is possible to provide a reactor and a method for producing hydrogen with high thermal efficiency that can quickly respond to load fluctuations and start-up / shutdown on the demand side X, and the obtained hydrogen is sent to, for example, a boiler, an industrial furnace, etc. for use.

[0130] [Sixth embodiment] FIG. 13 is a cross-sectional view showing the internal structure of a reactor 10B according to the sixth embodiment. The same components as those in the fifth embodiment are denoted by the same reference numerals and the description thereof will be omitted. In the sixth embodiment, the first catalyst section 13 is installed near the inlet 2, unlike in the first embodiment. Therefore, the first catalyst section 13 is disposed in a portion having a smaller horizontal cross-sectional area than the horizontal cross-sectional area of ​​the installation location of the second catalyst section 21. Furthermore, the shape between the inlet 2 and the upper end of the locally widened portion formed below the inlet 2 is a square tube (rectangular in top view). However, the shape of the inlet 2 may also be cylindrical (circular in top view).

[0131] A dispersion section 18 is provided below the first catalyst section 13, and the lower surface of the dispersion section 18 is arranged in the locally expanded portion. The thickness T1 of the heat insulating material 12 surrounding the first catalyst section 13 in the second embodiment is longer than the thickness T1 of the heat insulating material 12 surrounding the first catalyst section 13 in the first embodiment. Furthermore, in the second embodiment, the shape of the first catalyst section 13 is honeycomb-shaped, unlike the first embodiment. Therefore, the first catalyst section 13 is a honeycomb catalyst, similar to the second catalyst section 21. The specific structure of the first catalyst section 13 will be described later with reference to the third embodiment.

[0132] The experiment shown in FIG. 10 was also conducted for the sixth embodiment to verify its effectiveness. The experimental conditions were as follows: the first catalyst portion 13 was a honeycomb catalyst supporting platinum. The honeycomb catalyst had dimensions of width W1 = 150 mm, depth D1 = 150 mm, and height H1 = 50 mm. The amount of the first catalyst packed was 2.25 L. The other experimental conditions were the same as those shown in FIG. 10. The cross-sectional area of ​​the first catalyst portion 13 was 150 mm x 150 mm, W2 / W1 = 2, and T1 / T2 = 1.4.

[0133] Even when verified under such experimental conditions, the same effect as in the fifth embodiment (temperature distribution shown in FIG. 10) was obtained.

[0134] [Seventh embodiment] FIG. 14 is a cross-sectional view showing the internal structure of a reactor 10C according to the seventh embodiment. The same components as those in the fifth and sixth embodiments are denoted by the same reference numerals and the description thereof will be omitted. In the seventh embodiment, the casing 1 has an expanding section 17 between the inlet 2 and the second catalyst section 21, where the cross-sectional area of ​​the flow path 11 formed inside the casing 1 expands toward the downstream side with the gas flow. The heat insulating material 12 is arranged along the inner surface of the casing 1, and the thickness of the heat insulating material 12 is the same regardless of the location. Therefore, at the expanding section 17 of the casing 1, the cross-sectional area of ​​the flow path 11 defined by the heat insulating material 12 expands.

[0135] The first catalyst section 13 is disposed in the expansion section 17. By disposing it in this position, the heated gas G2 generated in the first catalyst section 13 spreads downward along the heat insulating material 12. This prevents the heated gas G2 from being blown against the heat insulating material 12, and prevents heat from being released to the outside of the reactor 10 through the heat insulating material 12.

[0136] In the example of the present disclosure, the first catalyst section 13 is installed inside the expansion section 17. Because both the first catalyst section 13 and the cylindrical body 15 have a rectangular shape, the size of the gap 16 increases on the side of the first catalyst section 13 as the gas flow moves downstream. In the first catalyst section 13, the temperature increases due to heat generated in the first flow path 131 as the gas flow moves downstream, so by making the gap 16 larger as the gas flow moves downstream, the insulating effect due to the presence of a gas phase can be increased.

[0137] By installing the first catalyst section 13 inside the reactor 10, for example, near the inlet 2, it is possible to prevent heat generated by the combustion of the combustible gas from being unintentionally released to the outside, and to raise the temperature of the gas G2 supplied to the second catalyst section 21 to a temperature effective for ammonia reforming (for example, 200°C or higher). This makes it possible to prevent damage to the reactor 10 (particularly the casing 1) due to heat. Furthermore, since ammonia reforming is performed, the reactor 10 can be quickly started up (prepared before ammonia reforming).

[0138] The first catalyst section 13 is disposed with a gap 16 between it and the surface 121 of the thermal insulator 12. The surface 121 is the surface facing the flow path 11 (the surface that defines the flow path 11) and is the surface that comes into contact with the gas G flowing inside the reactor 10. Since the gas G is present in the gap 16, a gas phase exists between the thermal insulator 12 and the first catalyst section 13. This makes it difficult for heat generated in the first catalyst section 13 to be transferred to the thermal insulator 12. Although the thermal insulator 12 has a thermal insulating effect, some heat transfer (heat dissipation to the outside) may occur. Therefore, the gap 16 prevents thermal contact between the first catalyst section 13 and the thermal insulator 12 (including contact via the solid cylindrical body 15), thereby suppressing heat dissipation to the outside of the reactor 10 and enabling effective use of the heat. Furthermore, damage to the housing 1 caused by heat can be suppressed.

[0139] The first catalyst section 13 is, for example, a honeycomb catalyst having a honeycomb shape, and has, for example, a rectangular first flow path 131 when viewed from above (not shown), but may have, for example, a circular, honeycomb, or hexagonal first flow path 131. The first catalyst section 13 has a rectangular shape (cubic, rectangular parallelepiped, etc.) with some thickness. The first catalyst section 13 includes the first flow path 131 and a first holder 132. The first flow path 131 is a flow path along the gas flow (gas flow in the flow path 11) formed between the inlet 2 and the outlet 3. The flow paths of the second catalyst section 21 of the first embodiment and the first catalyst section 13 and second catalyst section 21 of the second embodiment may also have, for example, a circular, honeycomb, or hexagonal shape.

[0140] The first holder 132 is a holder that defines the first flow path 131 and holds the first catalyst. By providing the first catalyst section 13 with the first flow path 131 and the first holder 132, a catalytic reaction can proceed with the gas G flowing through the first flow path 131 without significantly increasing the pressure loss of the gas G flowing through the flow path 11. More specifically, by suppressing the pressure loss of the first catalyst section 13 (pressure loss is proportional to the square of the linear velocity) while increasing the GHSV of the gas G flowing through the first catalyst section 13 as much as possible, the amount of the first catalyst used can be reduced and the reactor 10 can be made more compact.

[0141] There are no particular limitations on the method for supporting the first catalyst on the first holder 132. In the example of the present disclosure, for example, a raw material containing a binder (e.g., clay powder) can be extruded into the shape of the first catalyst section 13, and the catalyst component can be supported after firing. For example, in the first catalyst section 13 manufactured in this manner, the gas G1 flowing through the first flow path 131 diffuses into the first holder 132, and a catalytic reaction progresses inside the first holder 132 near the first flow path 131. However, the first catalyst may also be supported on, for example, the surface of the first holder 132 so as to face the first flow path 131.

[0142] The number of first flow paths 131 is not particularly limited. For example, when viewed from above the first catalyst section 13 (when the first catalyst section 13 is viewed from the inlet 2), 2 (1 inch 2 ) the number of cells in the first flow paths 131 is 200 to 2,000, preferably 400 to 1,200. The first flow paths 131 have the same cross-sectional area throughout the thickness direction of the first catalyst section 13, and extend linearly in the vertical direction. The first flow paths 131 are also arranged regularly at equal intervals.

[0143] The first flow path 131 is formed in a first holder 132. In the first catalyst section 13, the thickness of a corner wall (peripheral wall thickness) surrounding the first flow path 131, i.e., the thickness of a first end 133 (an end formed on a side of the first flow path 131) of the first holder 132, is thicker than the distance between adjacent first flow paths 131. A flammable gas such as hydrogen flows through the first flow path 131, and combustion of the flammable gas progresses in the first flow path 131. As a result, the first flow path 131 becomes hot (e.g., 150°C to 250°C, e.g., about 200°C), and the heat generated in the first catalyst section 13 is supplied to the second catalyst section 21 in the subsequent stage. Therefore, even if some heat radiation to the casing 1 is unavoidable, it is preferable to suppress the amount of heat unintentionally radiated from the first catalyst section 13 to the outside of the reactor 10 (heat radiation amount).

[0144] The sides of the first catalyst part 13 are surrounded by, for example, flexible (elastic) heat insulating material 14. This facilitates the inflow and outflow of gas G and also suppresses heat radiation to the sides. In particular, since the housing 1 is present on the sides of the first catalyst part 13, the heat insulating material 14 can suppress heat radiation to the housing 1. The heat insulating material 14 is made of, for example, a heat-resistant material having a filamentous or fibrous shape, and specifically, for example, rock wool, but is not limited to this.

[0145] The first catalyst section 13 is housed in, for example, a cylindrical body 15 having a bottom. The dispersion section 18 is provided on the bottom surface of the cylindrical body 15. As described above, the inlet 2 is formed in the housing 1, and the cylindrical body 15 is housed so as to fit into the inlet 2. Therefore, the gas G1 introduced through the inlet 2 flows into the cylindrical body 15, and then flows inside the cylindrical body 15, which also serves as the flow path 11.

[0146] The cylindrical body 15 includes a main body 151 that houses the first catalyst section 13. The outer shape of the main body 151 (for example, a square tube, a cylinder, etc.) matches the shape of the inlet 2 (for example, a rectangle, a circle, etc.).

[0147] A heat insulating material 14 is provided between the inner wall surface 154 of the cylindrical body 15 and the side surface 134 of the first catalyst section 13. The heat insulating material 14 is arranged so as to fill the space between the inner wall surface 154 and the side surface 134 as closely as possible. Furthermore, since the heat insulating material 14 is provided between the inner wall surface 154 and the side surface 134, the gas G1 introduced from the inlet 2 flows into the first flow path 131 without passing between the inner wall surface 154 and the side surface 134.

[0148] In this way, by disposing the heat insulating material 14 between the inner wall surface 154 and the side surface 134, a heat insulating effect is obtained. Furthermore, the first end 133 of the heat insulating material 14 is disposed so as to surround the first flow path 131, and heat is not generated at the first end 133 where the gas G1 does not flow, or outside the first end 133. Furthermore, the first end 133 makes it difficult for the heat generated in the first flow path 131 to be transferred to the outside. Therefore, it is possible to suppress unintentional heat dissipation to the outside of the reactor 10, and to improve the heat utilization efficiency. It is also possible to suppress damage to the housing 1 due to heat.

[0149] The second catalyst section 21 is constructed by arranging a plurality of (e.g., four) unit second catalyst sections 215 horizontally in a square shape and stacking them vertically in a plurality of stages (e.g., eight stages). By constructing the second catalyst section 21 by combining a plurality of unit second catalyst sections 215 in this way, the shape of the second catalyst section 21 can be flexibly changed to suit the design conditions such as the shape and size of the second catalyst section 21 and the location of the second catalyst section 21. However, the second catalyst section 21 does not need to be constructed from a plurality of unit second catalyst sections 215, and may be constructed in a single shape. Furthermore, the second catalyst section 21 is not limited to being rectangular (prism-shaped) and may be, for example, round (cylindrical).

[0150] The unit second catalyst portion 215 is the same as the first catalyst portion 13 except for the supported catalyst. Therefore, the explanations for the first catalyst portion 13 (manufacturing method, dimensions, shape, etc.) can be similarly applied to the unit second catalyst portion 215.

[0151] FIG. 15 is a cross-sectional view taken along line AA in FIG. 140, showing the second catalyst section 21 installed in the second stage. For example, the rectangular second catalyst section 21 is arranged inside the cylindrical casing 1, in the center of the casing 1 when viewed from above. The casing 1 may be rectangular (cylindrical with corners), for example. The insulating material 22 is wound around the second catalyst section 21 in the same way as the first catalyst section 13. The insulating material 22 is the same as the insulating material 14, except that it is wound around a different object. Furthermore, the insulating material 12 is arranged on the outside of the insulating material 22, in the same way as the first catalyst section 13.

[0152] Returning to FIG. 14 , the second catalyst section 21 is a honeycomb catalyst having a honeycomb shape, similar to the first catalyst section 13. In the illustrated example, the honeycomb shape has second flow paths 211 that are rectangular in top view, but the second flow paths 211 may also have, for example, a circular, honeycomb, or hexagonal shape. The second catalyst section 21 includes the second flow paths 211 and a second holder 212. The second flow paths 211 (second flow path) are flow paths along the gas flow (gas flow in the flow path 11) formed between the inlet 2 and the outlet 3. In the example of the present disclosure, the second flow paths 211 have the same cross-sectional area throughout the thickness direction of the second catalyst section 21 and extend linearly in the vertical direction. Furthermore, the second flow paths 211 are regularly arranged at equal intervals.

[0153] The second holder 212 is a holder that defines the second flow path 211 and holds the second catalyst. With the second catalyst section 21 having such a structure, a catalytic reaction can proceed with the gas G flowing through the second flow path 211 without significantly increasing the pressure loss of the gas G flowing through the flow path 11. As a result, by suppressing the pressure loss of the second catalyst section 21 (pressure loss is proportional to the square of the linear velocity) while increasing the GHSV of the gas G flowing through the second catalyst section 21 as much as possible, the amount of catalyst used can be reduced and the reactor 10 can be made more compact.

[0154] The second flow path 211 is formed in the second holder 212. The thickness of the end 213 (the lateral end of the second flow path 211) of the second holder 212 is thicker than the distance between adjacent second flow paths 211 so as to surround the second flow path 211. An exothermic reaction, which will be described later, progresses in the second flow path 211. As a result, the second flow path 211 becomes hot (for example, 600°C or higher and 800°C or lower), and heat generated in the first catalyst section 13 is supplied to the second catalyst section 21 in the subsequent stage. Therefore, even if some heat radiation to the casing 1 is unavoidable, it is preferable to suppress the amount of heat unintentionally radiated from the first catalyst section 13 to the outside of the reactor 10 (heat radiation amount). Therefore, similar to the first catalyst section 13, by providing the end 213, heat radiation to the outside can be suppressed.

[0155] In the seventh embodiment, an experiment similar to that shown in FIG. 10 was also carried out to verify the effects. The experimental conditions were the same as those of the second embodiment except that T1 / T2 = 1. Even when verified under these experimental conditions, the same effects as those of the fifth embodiment (temperature distribution shown in FIG. 10) were obtained. [Industrial Applicability]

[0156] The present invention can be applied to all ammonia-hydrogen mixed fuel production devices. [Explanation of symbols]

[0157] 1010A~1010D Ammonia-hydrogen mixed fuel production equipment 1011 Air 1013 Oxygen Separation Device 1014 Raw material supply department 1015 Reforming reactor 1016 Reformed gas 1017 Gas Component Analyzer 1018 Fuel 1 chassis Reactors 10A, 10B, and 10C 11 Flow path 12. Insulation 121 Surface 13 First catalyst section 131 First Channel 132 First holding body 133 First end 134 Side 14. Insulation 15 Cylinder 151 Main Unit 154 Inner wall surface 16 Gap 17 Enlarged section 18A 1st dispersion section 18B 2nd dispersion section 2. Introduction 21 2nd catalyst section 211 Second Channel 212 Second holding body 213 End 215 units second catalyst section 22 Insulation 3 exit 51 Heat exchanger 52 Tank 53 Pump 54 Outlet channel 54a Branch 54b Return flow path S1 Step (Introduction Step) S2 step (heating step) S3 step (modification step) S4 step (modification step)

Claims

1. an oxygen supply unit that supplies oxygen at a desired concentration; a raw material supply unit that supplies ammonia; a reforming reactor that converts the ammonia into hydrogen using oxygen having a desired concentration from the oxygen supply unit to produce a reformed gas; a combustible gas inlet for supplying a combustible gas other than ammonia to the reforming reactor; a gas component analyzer that measures the concentration of either or both of hydrogen and ammonia in the reformed gas from the reforming reactor; Along with providing the reforming reactor has a first catalyst and a second catalyst; 1. An apparatus for producing an ammonia-hydrogen mixed fuel, wherein the first catalyst is a platinum catalyst, and the second catalyst is an ammonia reforming catalyst consisting of an NH 3 -ATR catalyst alone or a combination of the NH 3 -ATR catalyst and an NH 3 decomposition catalyst.

2. 2. The apparatus for producing ammonia and hydrogen mixed fuel according to claim 1, wherein the oxygen supply unit is an oxygen separator that separates oxygen from air to a desired concentration.

3. The oxygen supply unit 2. The apparatus for producing ammonia and hydrogen mixed fuel according to claim 1, wherein the air dryer is an air dryer using either an adsorption method for removing moisture from supplied air by adsorption, or a cooling method for removing moisture by cooling at 20°C or less.

4. The oxygen supply unit, with respect to the supply amount of the ammonia, 2. The apparatus for producing ammonia-hydrogen mixed fuel according to claim 1, wherein 3 to 20% by volume of oxygen is added.

5. 3. The ammonia and hydrogen mixed fuel manufacturing device according to claim 1, wherein the amount of oxygen supplied from the oxygen supply unit is controlled based on the concentration of either or both of the hydrogen and the ammonia from the gas component analyzer.

6. 3. The ammonia-hydrogen blended fuel manufacturing apparatus according to claim 1, wherein a bypass line for supplying the ammonia from the raw material supply unit is provided between the reforming reactor and a measurement point of the gas component analyzer on the downstream side of the reforming reactor.

7. a bypass line for supplying ammonia from a raw material supply unit between the reforming reactor and a measurement point of the gas component analyzer on the downstream side of the reforming reactor; a storage tank provided between an ammonia introduction position of the bypass line and the reforming reactor, 3. The ammonia-hydrogen mixed fuel manufacturing device according to claim 1, wherein the gas composition of the reformed gas and the ammonia is adjusted according to the composition ratio of ammonia and hydrogen measured by the gas component analyzer and a required fuel composition ratio.

8. The reforming reactor a housing having an inlet for introducing ammonia and a flammable gas other than ammonia, and an outlet for discharging a generated gas; a first catalyst unit disposed inside the housing and including a first catalyst made of a platinum catalyst that generates heat by burning the combustible gas introduced from the inlet; and a second catalyst section provided with a second catalyst, the second catalyst being an ammonia reforming catalyst consisting of an NH 3 -ATR catalyst alone or a combination of the NH 3 -ATR catalyst and an NH 3 decomposition catalyst, which is disposed between the first catalyst section and the outlet, is heated by heat generated in the first catalyst section, and generates hydrogen from ammonia.

9. 9. The apparatus for producing ammonia and hydrogen mixed fuel according to claim 8, wherein the first catalyst portion is disposed between the inlet and the second catalyst portion.

10. 9. The apparatus for producing ammonia and hydrogen blended fuel according to claim 8, wherein the reforming reactor comprises a dispersion section between the first catalyst section and the second catalyst section, which disperses the gas flowing out from the first catalyst section toward the second catalyst section.

11. an outlet flow path for discharging hydrogen from the outlet; a tank provided in the outflow passage for storing the outflowed hydrogen; 9. The apparatus for producing ammonia and hydrogen mixed fuel according to claim 8, further comprising: a return flow path that branches off from a branching portion of the outflow flow path and returns the hydrogen to the inlet.

12. 3. A fuel supply system using the ammonia-hydrogen mixed fuel production device according to claim 1 or 2, wherein the ammonia-reformed fuel is supplied to a fuel demand section.

13. an introduction step of introducing an introduction gas containing ammonia and a combustible gas other than ammonia into a reforming reactor; a combustion step of selectively combusting the combustible gas in the introduced gas with a first catalyst; a second catalyst heating step of heating a second catalyst that generates hydrogen from ammonia using heat generated in the combustion step; a reforming step of stopping the introduction of the combustible gas after the temperature of the second catalyst reaches a predetermined temperature, and generating hydrogen from ammonia using the second catalyst; the reforming reactor comprises a first catalyst and a second catalyst; A method for producing hydrogen, wherein the first catalyst is a platinum catalyst, and the second catalyst is an ammonia reforming catalyst consisting of an NH 3 -ATR catalyst alone or a combination of the NH 3 -ATR catalyst and an NH 3 decomposition catalyst.

Images