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

Abstract

To provide an ammonia-hydrogen mixed fuel manufacturing device and a fuel supply system that can stably obtain hydrogen from ammonia even when the required fuel ratio changes. [Solution] An oxygen supply unit 1013 that supplies oxygen at a desired concentration, a raw material supply unit 1014 that supplies ammonia as a raw material gas at a desired concentration, and a reformed gas G that converts ammonia into hydrogen using oxygen at a desired concentration from the oxygen supply unit 1013. 12 and a reformed gas G from the reforming reactor 1015. 12 The reformed gas G is discharged from the reformed gas discharge line L4. 12 a gas component analyzer 1017 for measuring the concentration of either hydrogen or ammonia or both in the raw gas G 11 The raw material supply line L3 supplies the reformed gas G 12 The reformed gas discharge line is installed at the intersection of L4 and the reformed gas discharge line. 11 The high-temperature reformed gas G 12 and a plate-type heat exchanger 1030 for exchanging heat.

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] However, the fuel composition (hydrogen (H2) / ammonia (NH3) composition ratio) and flow rate may fluctuate depending on the requirements of downstream boilers, gas engines, industrial furnaces, etc. When such fluctuations are large (for example, a change from a turndown ratio of 1:1 (load factor 100%) to a turndown ratio of 5:1 (20%)), it is difficult to respond quickly and with stable control 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 the present invention is, for example, 100 m 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 daily start-and-stop (DSS) operations, so they must respond quickly to load fluctuations and DSS. Furthermore, because they are small- to medium-sized, the reactor size is small, and if a lot of heat is 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 respond easily and quickly 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 complicated and the time it takes to heat makes it difficult to respond quickly. Furthermore, if the turndown ratio is less than 30% of the design flow rate (load rate < 30%, hereinafter also referred to as "low load rate less than 30%), the measurement accuracy and control accuracy of the gas flow rate in the system, the reaction efficiency of the ATR, and the heat transfer coefficient of the heat exchanger will decrease, making it difficult to operate the device efficiently and stably.

[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 (O2) at a desired concentration; a raw material supply unit that supplies ammonia (NH3) as a raw material gas at a desired concentration; a reforming reactor that converts ammonia (NH3) into hydrogen (H2) using oxygen of a desired concentration from the oxygen supply unit to produce a reformed gas; a combustible gas supply unit that supplies a combustible gas other than the ammonia to the reforming reactor; a gas component analyzer provided in a reformed gas discharge line for discharging the reformed gas from the reforming reactor, the gas component analyzer measuring the concentration of either or both of hydrogen and ammonia in the reformed gas; a plate-type heat exchanger that is provided at an intersection between a raw material supply line that supplies the raw material gas of ammonia and oxygen and a reformed gas discharge line that discharges the reformed gas, and that exchanges heat between the raw material gas and the high-temperature reformed gas; a control device that controls the supply amount of the oxygen to the ammonia; 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 an ammonia reforming catalyst in combination with a cracking catalyst, Furthermore, in the control device, The composition ratio of the fuel in the reformed gas (NH 3 / H 2 ) by the gas component analyzer to measure the fuel composition required by the demand side, and controlling the oxygen supply amount based on the measured value obtained by the measurement, The temperature of the raw material gas introduced into the reforming reactor is increased by heat exchange with the high-temperature reformed gas flowing out from the reforming reactor using the plate-type heat exchanger. The present invention is characterized by comprising:

[0011] (2) Another aspect of the present invention is an ammonia-hydrogen mixed fuel production apparatus according to the invention (1), further comprising: a storage tank provided in the reformed gas discharge line for storing the reformed gas; The reformed gas supply line is characterized by being provided with a recycle line that branches off from the reformed gas discharge line at a branching point and recycles a portion of the reformed gas to the raw material supply line.

[0012] (3) Another aspect of the present invention is an ammonia-hydrogen mixed fuel production apparatus according to the invention (2), characterized in that oxygen from the oxygen supply unit is directly introduced into the reforming reactor.

[0013] (4) Another aspect of the ammonia-hydrogen mixed fuel manufacturing apparatus according to the present invention is characterized in that, in the invention of (1) or (2), the oxygen supply unit is an oxygen separation device that separates oxygen from air to a desired concentration.

[0014] (5) Another aspect of the ammonia-hydrogen mixed fuel manufacturing apparatus according to the present invention is characterized in that, in the invention of (1) or (2), the oxygen supply unit is an air dryer that removes moisture from the supplied air.

[0015] (6) Another aspect of the present invention is an apparatus for producing ammonia-hydrogen mixed fuel according to the invention (1) or (2), characterized in that the oxygen supply unit adds 3 to 20 volume % of oxygen to the amount of ammonia supplied.

[0016] (7) Another aspect of the ammonia-hydrogen mixed fuel manufacturing device according to the present invention is characterized in that, in the invention of (1) or (2), 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.

[0017] (8) An apparatus for producing ammonia-hydrogen mixed fuel according to one embodiment of the present invention is In the invention of (1), 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 that generates heat by burning the combustible gas introduced from the inlet; a second catalyst disposed between the first catalyst section and the outlet, heated by heat generated in the first catalyst section, and generating 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.

[0018] (9) Another aspect of the ammonia-hydrogen mixed fuel production apparatus according to the present invention is In the invention of (8), The first catalyst portion is disposed between the inlet and the second catalyst portion.

[0019] (10) An apparatus for producing ammonia-hydrogen mixed fuel according to one embodiment of the present invention comprises: In the invention of (8), The aforementioned Modification The reactor includes, between the first catalyst section and the second catalyst section, Or between the inlet and the first catalyst part, The present invention is characterized by comprising a dispersion section that 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 In the invention of (8), an outlet flow path through which the reformed gas containing hydrogen flows out from the outlet; a tank provided in the outlet flow path for storing the outflowed reformed gas containing hydrogen; a return flow path that branches off from the branching portion of the outflow flow path and returns the reformed gas containing hydrogen to the inlet.

[0021] (12) Another aspect of the fuel supply system according to the present invention is (2) The ammonia-hydrogen mixed fuel production equipment is used, and in the case of low load operation with a turndown ratio of less than 30%, a portion of the reformed gas is supplied to the reforming reactor side as recycled gas.

[0022] (13) Another aspect of the method for producing hydrogen according to the present invention is (1) or (8) Using the ammonia-hydrogen mixed fuel production device, An introduction gas containing ammonia and a flammable gas other than ammonia The aforementioned introducing the mixture 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; and a reforming step of stopping the introduction of the combustible gas after the temperatures of the first catalyst and the second catalyst reach a predetermined temperature, and generating hydrogen from ammonia using the second catalyst. Along with 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 flow rate of fuel changes (for example, when the load factor is low and the load is less than 30%), hydrogen can be stably obtained from ammonia.

[0024] A plate-type heat exchanger is installed at the intersection of the inlet feed gas inlet line and the reformed gas outlet line, and this plate-type heat exchanger is used to exchange heat between the inlet feed gas introduced into the reforming reactor and the high-temperature reformed gas flowing out of the reforming reactor, thereby raising the inlet temperature of the feed gas. This reduces the consumption of fuel (reformed H2) required to raise the temperature of the inlet feed gas.

[0025] Furthermore, when the turndown ratio in the system falls below 30%, a portion of the reformed gas can be recycled to the inlet of the reforming reactor as recycled gas to maintain the flow rates in the heat exchange process and reaction process at a certain level (>30%), thereby preventing a decrease in the controllability of the system, measurement accuracy of gas flow rate, etc., and the thermal efficiency of the system.

[0026] As described above, the present invention can provide a reactor and a method for producing hydrogen that are highly thermally efficient and can quickly respond to load fluctuations and start-up / shutdown on the demand side. [Brief explanation of the drawings]

[0027] [Figure 1A] 1 is a schematic diagram of an apparatus for producing ammonia-hydrogen mixed fuel according to a first embodiment of the present invention. [Figure 1B] FIG. 3 is a schematic diagram of an apparatus for producing an ammonia-hydrogen mixed fuel according to a modified example of the first embodiment of the present invention. [Figure 2A] 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 2B] 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 3A] FIG. 4 is a schematic diagram illustrating a test process of the ammonia-hydrogen mixed fuel production apparatus according to the second embodiment of the present invention. [Figure 3B]FIG. 4 is a schematic diagram illustrating a test process of the ammonia-hydrogen mixed fuel production apparatus according to the second embodiment of the present invention. [Figure 4A] FIG. 10 is a schematic diagram of the process of an ammonia-hydrogen mixed fuel production apparatus according to a third embodiment of the present invention. [Figure 4B] FIG. 10 is a schematic diagram of the process of an ammonia-hydrogen mixed fuel production apparatus according to a third 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 of the present invention. [Figure 5B] FIG. 10 is a structural diagram of a dispersion section installed inside a reactor according to a fifth embodiment of the present invention. [Figure 5C] FIG. 10 is a structural diagram of another dispersion section installed inside a reactor according to a fifth embodiment of the present invention. [Figure 5D] FIG. 10 is a cross-sectional view showing the internal structure of another reactor according to the fifth embodiment of the present invention. [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 of the present invention. [Figure 14] FIG. 10 is a cross-sectional view showing the internal structure of a reactor according to a seventh embodiment of the present invention. [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

[0028] 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.

[0029] [First embodiment] 1A 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. 1A, the apparatus for producing ammonia-hydrogen mixed fuel 1010A-1 of this embodiment includes an oxygen supply unit 1013 that supplies oxygen (O) of a desired concentration, a raw material supply unit 1014 that supplies a raw material (ammonia (NH)) of a desired concentration, and a gas supply unit 1015 that converts ammonia (NH) supplied from the raw material supply unit 1014 into hydrogen (H) using oxygen of the desired concentration from the oxygen supply unit 1013 to produce a reformed gas G. 12 and a reformed gas G from the reforming reactor 1015. 12 and a gas component analyzer 1017 for analyzing the concentration of either or both of hydrogen and ammonia in the gas.

[0030] 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. The oxygen supply unit 1013 supplies oxygen (O2) as a raw material, and supplies oxygen (O2) from the oxygen supply unit 1013 to the reforming reactor 1015 via an oxygen supply line L2. The supplied oxygen (O2) and ammonia (NH3) are joined at the joining point A, and are introduced into the inlet raw material gas G 11 The resulting mixture is introduced into the reforming reactor 1015 as the oxidized gas.

[0031] In addition, the reformed gas G discharged from the reforming reactor 1015 12is used as a product (fuel (H2)) 1018 on the external demand side X via a reformed gas discharge line L4. In FIG. 1, reference numeral 1020 denotes a cooler installed in the reformed gas discharge line L4, 1021 denotes a water separator, 1022 denotes a compressor, and 1023 denotes a storage tank (hereinafter also referred to as a "product tank") for storing the reformed gas.

[0032] Examples of the oxygen supply unit 1013 that supplies oxygen include devices that separate oxygen (O2) from air, such as a cryogenic separation device, a pressure swing adsorption (PSA) device, and a membrane separation device, but the present invention is not limited to these.

[0033] Furthermore, an air dryer, for example, that removes moisture from the supplied air may be used as the oxygen supply unit 1013 other than the pressure swing adsorption (PSA) unit. The air dryer can be classified into an adsorption method and a cooling method.

[0034] The air dryer removes moisture from the air and prevents a catalyst such as platinum (Pt) used in the reforming reactor 1015 from being inhibited by water adsorption.

[0035] Here, the adsorption method is, for example, a method of removing moisture using zeolite. 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 less). The cooling temperature is preferably 20°C or less, and more preferably -20°C or less.

[0036] According to this embodiment, when oxygen is supplied from the air and moisture in the air is removed by an air dryer, for example, a platinum (Pt) catalyst used in the reforming reactor 1015 is prevented from being poisoned by moisture.

[0037] In addition, a gas component analyzer 1017 is installed in the reformed gas discharge line L4 to measure the composition ratio (NH3 / H2) of ammonia (NH3) and hydrogen (H2), or the gas composition of either one of the fuel 1018, and the reformed gas G 12 The gas composition is measured.

[0038] Examples of the gas component analyzer 1017 include a hydrogen concentration meter that analyzes hydrogen, an ammonia analyzer that analyzes ammonia, and an ammonia-hydrogen composition analyzer that simultaneously measures the compositions of hydrogen and ammonia, but the present invention is not limited to these. Here, the main analyzer used as the gas component analyzer 1017 may be, for example, a gas chromatograph (for analysis of H2 and NH3 gases), a thermal conductivity gas analyzer (for analysis of H2 gas), or an infrared absorption spectrophotometer (for analysis of NH3 gas), but is not limited to these in the present invention.

[0039] In this way, the raw material ammonia (NH3) is reformed in the reforming reactor 1015 to produce the reformed gas G 12 The composition ratio (NH3 / H2) in the mixture is measured by a gas component analyzer 1017, whereby the fuel composition required on the downstream demand side X is measured intermittently or continuously.

[0040] This measurement value is sent online as a measurement signal to a separate control device 1031, and the control valve V 11 , V 12 The opening and closing of the valve may be controlled automatically by mass flow control. As an example, the control device 1031 may perform control to correct the difference between the fuel composition requested by the demand unit X and the measured fuel composition.

[0041] 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 hydrogen (H2) yield and thermal efficiency.

[0042] 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 ammonia (NH3) and hydrogen (H2) in a heating furnace and supplied to the reforming reactor 1015. NH3→0.5N2+1.5H2 endotherm △H=+45.9 kJ / mol …(1) However, as the ammonia (NH3) decomposition reaction progresses, the reaction temperature drops and the reaction will eventually stop unless heat is supplied.

[0043] 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) NH3 + 0.75O2 → 0.5N2 + 1.5H2O Exothermic reaction △H = -317kJ / mol … (3)

[0044] 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.

[0045] As the reforming catalyst 1015A of 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. Here, it is preferable that the catalyst temperature of the "NH3·ATR catalyst" is 150 to 750°C, and the catalyst temperature of the "NH3 decomposition catalyst" is 400 to 750°C.

[0046] When the optimal catalyst is combined for the ammonia decomposition reaction (formula 1) and the ammonia oxidation reaction (formulas 2 and 3) as described above, the oxidation reaction proceeds 100% in 20 to 30% of the entire catalyst layer because of its fast reaction rate, whereas the decomposition reaction requires a large amount of catalyst because its reaction rate is slower than the oxidation reaction and the reaction temperature drops as the reaction progresses.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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 MPaG, preferably 0.07 to 0.7 MPaG. The reason for specifying the temperature and pressure within the predetermined ranges is to allow the reforming reaction to proceed efficiently.

[0051] The oxidation reaction of ammonia (NH3) 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. If the temperature inside the reforming reactor 1015 exceeds, for example, 700°C, the activity of the catalyst may decrease (for example, if the aggregation of active metals due to heat is promoted, reducing the active surface area). Therefore, the reaction temperature is preferably in the range of 150 to 750°C.

[0052] Furthermore, the lower the pressure, the more favorable it is for hydrogen production in terms of chemical equilibrium, but considering the supply pressure to the downstream combustion equipment and the pressure loss due to the catalyst layer, etc., a pressure of 0.03 to 0.9 MPaG is preferable. Note that when a honeycomb catalyst (which has low pressure loss) is used as the catalyst, or depending on the downstream equipment, a low pressure such as 0.07 MPaG may be more favorable for the reaction.

[0053] 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 to mix it with the raw material ammonia (NH3) to use as fuel, thereby building a fuel supply system that meets the requirements (NH3 / H2 composition, flow rate) from the demand side X.

[0054] 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.

[0055] That is, in response to the demand (NH3 / H2 composition, flow rate) of fuel 1018 from the demand unit X, such as an engine, boiler, or heating furnace, which is located downstream, a gas component analyzer (hydrogen concentration meter) 1017 installed downstream of the reforming reactor 15 analyzes the reformed gas G 12The hydrogen (H2) concentration in the mixture is measured, and the amount of oxygen supplied from the oxygen separator 1013 is controlled so as to satisfy the required H2 concentration (NH3 decomposition rate).

[0056] 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 + 0.25O2 → H2 + 0.5N2 + 0.5H2O …(5) <Exothermic reaction> NH3 + 0.75O2 → 0.5N2 + 1.5H2O … (6) <Exothermic reaction>

[0057] The heat generated by the oxidation reaction of ammonia (NH3) of the above-mentioned formulas (5) and (6) is used to promote the endothermic NH3 decomposition reaction of 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.

[0058] 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.

[0059] Here, conventionally, the O2 / NH3 ratio is increased and a part of H2 and NH3 is catalytically combusted to heat the inside of the reforming reactor 1015. However, when such internal heating is performed, the reformed gas G 12 The H2 in the fuel cell is consumed, resulting in increased self-consumption losses.

[0060] In this embodiment, such a reformed gas G 12Inlet feed gas G is introduced into the reforming reactor 1015 using a highly efficient plate-type heat exchanger 1030 to minimize self-consumption losses of H2 during 11 The gas temperature of the reformed gas G of the high-temperature gas flowing out of the reforming reactor 1015 is 12 The inlet raw material gas G 11 The introduction temperature of the

[0061] The plate-type heat exchanger 1030 is installed at the inlet raw material gas G 11 The inlet raw material gas G is introduced at the intersection of the inlet raw material gas G3 and the outlet reformed gas line L4. 11 The high-temperature reformed gas G 12 By exchanging heat with the water, the temperature can be raised to, for example, 450°C or higher.

[0062] By such a temperature raising operation, the inlet raw material gas G introduced into the reforming reactor 1015 11 As a result, the gas temperature of the inlet raw material gas G is increased compared to when the plate-type heat exchanger 1030 is not installed or when other types of heat exchangers (for example, shell-and-tube type heat exchangers) are installed. 11 This reduces the consumption loss of fuel (H2) required to raise the temperature.

[0063] In this way, the inlet source gas G 11 A plate-type heat exchanger 1030 is installed at the intersection of the inlet line L3 and the reformed gas discharge line L4, and this highly efficient plate-type heat exchanger 1030 is used to heat the inlet raw material gas G introduced into the reforming reactor 1015. 11 The temperature of the hot reformed gas G flowing out from the reforming reactor 1015 is 12 This increases the heat exchange rate of the inlet raw gas G 11 This reduces the consumption of fuel (reformed H2) required to raise the temperature of the reformed gas G 12 This can reduce the self-consumption loss of H2 during operation. In this way, the reformed gas G 12By measuring the H2 concentration in the gas with an in-line gas component analyzer (hydrogen concentration meter) 1017, the O2 / NH3 ratio can be controlled so that the H2 concentration satisfies the product gas specifications. In addition to improving the heat transfer coefficient, the plate-type heat exchanger 1030 is compact, lightweight, and can be freely laid out horizontally or vertically, making it suitable for small installation locations for small and medium-sized businesses.

[0064] In this embodiment, the inlet source gas G 11 The reformed gas G at the outlet of the reforming reactor 1015 is heated to a temperature (T1) of 450°C, preferably 500°C or higher. 12 Heat is exchanged in the plate-type heat exchanger 1030 so that the gas temperature (T2) becomes a high-temperature reformed gas of 550°C or higher (preferably 580°C).

[0065] In addition, the heat exchange in the plate type heat exchanger 1030 is performed by using the high temperature reformed gas G 12 The inlet temperature (T in ) and low temperature gas (inlet raw gas G 11 ) outlet temperature after heat exchange (T out It is preferable to carry out heat exchange so that the temperature difference (Δt) between the first and second electrodes is, for example, 10 to 150°C, and preferably 50 to 20°C.

[0066] This is because when the temperature difference (Δt) exceeds 150°C, the inlet raw material gas G 11 This is because, in order to heat the NH3 / O2 mixture, the O2 / NH3 ratio increases, resulting in a decrease in thermal efficiency, which is undesirable. Also, when the temperature difference (Δt) is less than 10°C, the heat transfer area of ​​the plate-type heat exchanger 1030 must be increased, which increases the cost and pressure loss of the plate-type heat exchanger 1030, both of which are undesirable.

[0067] The plate-type heat exchanger 1030 is preferably a gas-gas plate-type heat exchanger having high heat resistance of at least 500°C or more, more preferably 600°C or more.

[0068] Examples of the plate heat exchanger 1030 include a plate heat exchanger manufactured by Chandon Wintec Technology and a plate heat exchanger manufactured by Bosal Energy, but the present invention is not limited to these.

[0069] (Test Examples 1 and 2, Comparative Example 1) Test examples and comparative examples according to the first embodiment will be described below, but the present invention is not limited to these. Source gas G consisting of NH3 and air 11 The reformed gas G 12 After being heated by heat exchange with the NH3, the NH3 was supplied to the reforming reactor 1015 to carry out the oxidation and decomposition reaction.

[0070] (Comparative Example 1) As a comparative example, the inlet source gas G 11 and reformed gas G 12 The heat exchanger used was a shell and tube type heat exchanger. The outlet temperature of the reformed gas G was 600°C. 12 and inlet source gas G 11 The raw gas G is then heat exchanged using a shell and tube heat exchanger. 11 The mixture was heated from 30° C. to 400° C. and supplied to the reforming reactor 1015.

[0071] The ammonia decomposition rate at this time was 97%. The supply rates of ammonia and air were 300 Nm 3 / hr, 204Nm 3 / hr, and the O2 / NH3 molar ratio was 0.143. The reforming catalyst 1015A was 40 L of a Co-based catalyst packed into the reforming reactor 1015, and the inlet pressure of the reforming reactor 1030 was 0.13 MPaG. The thermal efficiency at this time was 78.9%. Here, the thermal efficiency is It is defined as "thermal efficiency = (energy of reformed gas / energy of raw material) x 100".

[0072] (Test Example 1) In Test Example 1, the inlet raw material gas G11 and reformed gas G 12 A plate-type heat exchanger 1030 was used for heat exchange with the reformed gas G with an outlet temperature of 600°C. 12 and inlet source gas G 11 The raw material gas was heated from 30° C. to 520° C. by heat exchange with the gas, and then supplied to the reforming reactor 1015. The ammonia decomposition rate at this time was 97%. The supply rates of ammonia and air were 300 Nm 3 / hr, 177Nm 3 / hr and the O2 / NH3 molar ratio was 0.124. The reforming catalyst 1015A was packed into the reforming reactor 1015 together with 40 L of Co-based catalyst, and the inlet pressure of the reactor was 0.13 MPaG. The thermal efficiency at this time was 81.2%.

[0073] (Test Example 2) In Test Example 2, the inlet raw material gas G 11 and reformed gas G 12 The heat exchanger is a plate type heat exchanger 1030, and the outlet temperature of the reformed gas G is 600°C. 12 and inlet source gas G 11 The raw material gas was heated from 30° C. to 580° C. (60° C. higher than in Test Example 1) by heat exchange with the feed gas, and then supplied to the reforming reactor 1015. The ammonia decomposition rate at this time was 97%. The supply rates of ammonia and air were 300 Nm 3 / hr, 164.2Nm 3 / hr and the O2 / NH3 molar ratio was 0.124. The reforming catalyst 1015A was packed into the reforming reactor 1015 together with 40 L of Co-based catalyst, and the inlet pressure of the reactor was 0.13 MPaG. The thermal efficiency at this time was 82.4%.

[0074] From the results of Comparative Example 1 and Test Examples 1 and 2, it can be seen that by using the plate-type heat exchanger 1030, the reformed gas G 12 and inlet source gas G 11By exchanging heat with high efficiency, it was confirmed that thermal efficiency was improved.

[0075] [Modification of the first embodiment] 1B is a schematic diagram of an apparatus for producing an ammonia-hydrogen mixed fuel according to a modified example of the first embodiment. Note that the same components as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted. 1B, the ammonia-hydrogen mixed fuel production apparatus 1010A-2 of this embodiment is the same as the ammonia-hydrogen mixed fuel production apparatus 1010A-1 of Embodiment 1, except that a hydrogen introduction line L9 is provided to introduce hydrogen (H2) from a hydrogen supply unit 1019 into a reforming reactor 1015. In addition, as a reforming catalyst 1015A in the reforming reactor 1015, a first catalyst unit 13 is disposed on the inlet side, and a second catalyst 21 is disposed on the gas flow downstream side of the first catalyst unit 13.

[0076] The first catalyst portion 13 is a platinum catalyst such as platinum for burning hydrogen, and the second catalyst is either a known NH3·ATR catalyst or a known NH3 decomposition catalyst, or both. This hydrogen introduction line L9 introduces hydrogen into the first catalyst 13 when the system is initially started up, and the introduction of hydrogen causes catalytic combustion, thereby increasing the internal temperature within the reforming reactor 1015 (details will be described later).

[0077] In addition, reformed gas G is used as a hydrogen source other than when the system is started up. 12 When the reformed gas G from the product tank 1023 can be used, 12 reformed gas introduction line L 10 Here, the reformed gas introduction line L 10 A moisture removal section 1026 for removing moisture contained in the reformed gas is provided in the reformed gas. In addition, hydrogen introduction line L9 and reformed gas line L 10 are provided with on-off valves V4 and V5 for controlling the introduction of hydrogen or reformed gas, respectively.

[0078] At the initial stage of system startup, the on-off valve V4 is opened to introduce hydrogen from the hydrogen supply unit (for example, a hydrogen cylinder) 1019. By introducing this hydrogen, the inlet raw material gas G 11 Inlet source gas G with hydrogen (H2) added 11 Then, the inlet raw material gas G to which hydrogen (H2) is added can be 11 is introduced into the housing 1 from the inlet 1a at room temperature (for example, 30°C) and reaches the first catalyst section 13. By using platinum as a catalyst in this first catalyst section 13, hydrogen combustion begins, and as a result, the inlet raw material gas G 11 The gas temperature is increased to heat the second catalyst section 21.

[0079] This is because, at the time of system startup, the entire system is at room temperature (low temperature), so that no external heating is required using a separate heat source, but the second catalyst section 21 is heated by catalytic heating inside the reforming reactor 1015, thereby promoting the ammonia reforming reaction (details will be described later). After the catalyst heating is completed, the on-off valve V4 is closed to stop the supply of hydrogen from the hydrogen supply unit (for example, hydrogen cylinder) 1019.

[0080] In this way, at the start of system operation, in addition to the hydrogen supply from the hydrogen supply unit (hydrogen cylinder) 1019, reformed gas (product hydrogen) G from the product tank 1023 is supplied. 12 By using this, consumption of the hydrogen supply unit (hydrogen cylinder) 1019 can be reduced.

[0081] [Second embodiment] 2A and 2B are schematic diagrams of an apparatus for producing ammonia-hydrogen mixed fuel according to the second embodiment. 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 FIGS. 2A and 2B, the ammonia-hydrogen mixed fuel production apparatus 1010B (1010B-1, 1010B-2) of this embodiment is the same as the ammonia-hydrogen mixed fuel production apparatus 1010A of the first embodiment, except that it is further provided with a reformed gas discharge line L4, and12 The product tank 1023 is a reformed gas storage tank that stores the reformed gas G, and the reformed gas G is branched off from the reformed gas discharge line L4 at a branch point B and sent to the raw material supply line L3. 12 Part of the recycled gas G 13 We have also set up recycling line L6, which recycles waste as recycled materials. The recycle line L6 is connected to the gas junction C on the inlet side of the plate-type heat exchanger 1030 of the introduction line L3. 11 Reformed gas G 12 Some of it is recycled and mixed.

[0082] In this embodiment, in the ammonia-hydrogen mixed fuel production apparatus 1010B-1, as shown in FIG. 2A, in the case of low load operation (less than 30% but 15% or more) of the load factor being less than 30%, the reformed gas G is supplied to the inlet line L3 of the reforming reactor 1015. 12 Part of the recycled gas G 13 The raw gas G 11 Reformed gas G 12 We provide an NH3 reforming system that can handle low load fluctuations by replenishing the fuel.

[0083] In the case of normal operation (load factor: 100% to 30%), as in the ammonia-hydrogen mixed fuel production apparatus 1010B-2 shown in FIG. 2B, the on-off valve V1 is set to "closed" and the recycled gas G is supplied to the recycling line in the same manner as in the configuration of the first embodiment (FIG. 1). 13 The operation will be such that no power is supplied.

[0084] In this way, the reformed gas G 12 Part of the reformed gas is recycled 13 By returning the gas to the reforming reactor 1015 side as a gas, the flow rate of the gas flowing through the reforming reactor 1015 system is maintained at 30% or more of the design flow rate.

[0085] Here, the reformed gas G consisting of H2 and N2 12 Recycle gas G 13However, if the gas is recycled as a fuel, energy is consumed to heat it up to the reaction temperature, resulting in a decrease in thermal efficiency.

[0086] In the case of the reforming reactor 1015, the O2 / NH3 ratio is increased and heating is performed by burning part of the H2 and NH3, resulting in increased loss of H2. To solve this problem, in this embodiment, as in the first embodiment, a highly efficient plate-type heat exchanger 1030 is used to change the temperature of the inlet raw material gas introduced into the reforming reactor 1015 to that of the high-temperature reformed gas G flowing out of the reforming reactor 1015. 12 This is increased by heat exchange with As a result, the source gas G 11 This significantly reduces the consumption of fuel (H2) required to raise the temperature.

[0087] In the present invention, the "design flow rate" refers to the maximum flow rate (flow rate) supplied to the reforming reactor 1015, which is the sum of the flow rates of the raw materials NH3 and oxygen (air), and 100% corresponds to the maximum flow rate. Therefore, "30%" corresponds to 30% of this design (maximum) flow rate on a volume (Vol) basis.

[0088] Here, the reformed gas G with a low turndown ratio 12 Recycle gas G 13 When the recycled gas is recycled to the reforming reactor 1015 as the recycled gas G 13 The H2 in the mixture may mix with the raw air (oxygen (O2)) and enter the hydrogen explosion concentration range.

[0089] Therefore, in this embodiment, an oxygen bypass line L7 is provided to bypass the supply of oxygen (O2) when oxygen is supplied to the reforming reactor 1015. Then, oxygen is directly introduced into the reforming reactor 1015 via the oxygen bypass line L7 and an oxygen burner. In this embodiment, NH3 and oxygen are introduced using separate lines (introduction line L3, oxygen bypass line L7) and separate burners (not shown).

[0090] Alternatively, instead of using separate burners, gases may be supplied to the reforming reactor 1015 through separate lines (inlet line L3, oxygen bypass line L7), and a combined burner capable of introducing two types of gases (NH3, O2) may be installed at the inlet of the reforming reactor 1015, so that the two types of gases are introduced into the reforming reactor 1015.

[0091] Next, the operation steps during low-load turndown using the recycle line L6 will be described with reference to FIGS. 3A and 3B. <Normal demand operation (turndown ratio: 100% to 30%)> In normal operation (turndown ratio: 100% to 30%), as shown in FIG. 3A, the on-off valve V1 is closed and the operation is performed in the same manner as in the configuration of the first embodiment (FIG. 1).

[0092] <Low load operation with a turndown ratio of less than 30% (turndown ratio: 15% to 30%)> [Step 0] Normally, the demand side X operates at a turndown rate of 30% to 100% (turndown operation) (see FIG. 3A).

[0093] [Step 1] In step 1, the demand unit X requests low load operation with a turndown ratio of less than 30% (turndown ratio: less than 30%; in this example, turndown ratio: 20%) to be input to the control unit 1031.

[0094] [Step 2] In step 2, the on-off valve V1 is changed from closed to open in response to a signal S from the control unit 1031 (see FIG. 3B).

[0095] [Step 3] In step 3, the reformed gas G 12 A part of the gas is recycled through the recycling line L6. 13 Dispose of as waste (recycling begins). Reformed gas G 12 Part of the recycled gas G 13By returning the gas to the reforming reactor 1015 side as a gas, the flow rate of the gas flowing through the reforming reactor 1015 system is maintained at 30% or more of the design flow rate.

[0096] [Step 4] In step 4, a change in the demand (turndown ratio: from 20% to 80%) is input to the control unit 1031 from the demand unit X side.

[0097] [Step 5] In step 5, the on-off valve V1 is changed from open to closed, the recycle is stopped, and normal operation is resumed (see FIG. 3A).

[0098] In this way, in the case of low load operation where the turndown ratio in the system is less than 30% (turndown ratio: less than 30%; in this example, turndown ratio: 20%), the reformed gas G 12 Part of the recycled gas G 13 By recycling the gas as a gas, the flow rate of the heat exchange process and reaction process can be maintained at a certain level (>30%). This prevents a decrease in the controllability of the system, measurement accuracy of gas flow rate, etc., and thermal efficiency of the system.

[0099] (Test Example 3) In Test Example 1, the system configuration shown in FIG. 1 was used, and the supply rates of ammonia (NH3) and oxygen (O2) were each 60 Nm 3 / hr, 35.4Nm 3 The operation was the same as in Test Example 1, except that the fuel consumption was 1000 kJ / hr and the turndown ratio was 20% (low load operation with a turndown ratio of less than 30%). The gas flow velocity in the hot side passage of the plate heat exchanger 1030 decreased from 10.5 m / s in Test Example 1 to 2.1 m / s, and the gas flow velocity in the reforming reactor 1015 decreased from 6.4 m / s to 1.9 m / s.

[0100] As a result, the overall heat transfer coefficient of the plate heat exchanger 1030 is 40Wm 2 / K to 12Wm 2 / K.

[0101] Due to the decrease in the overall heat transfer coefficient and the uneven flow of gas, the inlet raw gas G 11 Reactor inlet temperature (heat exchanger outlet temperature) T 11 The increase in temperature was limited to 180°C.

[0102] To compensate for this temperature drop, the supply of air (O2) from the oxygen supply unit 1014 was increased to 48.8 Nm 3 / hr, and the O2 / NH3 ratio at this time was set to 0.171. The ammonia decomposition rate was 92%, and the thermal efficiency was 70.3%.

[0103] (Test Example 4) In Test Example 3, The system configuration shown in Figure 2A was used, and the supply rates of ammonia (NH3) and air (O2) were set at 60 Nm 3 / hr, 35.4Nm 3 / hr and the turndown ratio was 20%.

[0104] 90Nm with recycling line L6 3 / hr recycled gas G 13 The flow rate of the mixed gas of ammonia (NH3) and reformed gas is 150 Nm 3 The procedure was the same as in Test Example 3, except that the temperature was changed to / hr.

[0105] Reformed gas is recycled gas G 13 By recycling as ethanol, the turndown ratio increased to 50%, and the inlet temperature of the raw material reforming reactor 1015 was accordingly increased to 400°C. To compensate for this temperature drop, oxygen (O2) was added at 50.3 Nm 3 / hr.

[0106] Here, the air was bypassed through an oxygen bypass line L7 that bypassed the plate-type heat exchanger 1030, and was directly supplied to the reforming reactor 1015 via a burner. The NH3 decomposition rate was 96%, and the thermal efficiency was 73.6%.

[0107] Test Examples 2 and 3 show that a part of the reformed gas is used as the bypass gas G 13 By recycling it as fuel, thermal efficiency improved from 70.3% to 73.6%.

[0108] Comparing Test Example 3 and Test Example 4, in Test Example 3, the reformed gas was not recycled, so the thermal efficiency dropped to 70.3%, but by recycling the reformed gas as in Test Example 4, the thermal efficiency increased to 73.6%, an improvement of approximately 3%.

[0109] As a result, even during low-load operation where the turndown ratio is less than 30%, which is the lower limit of the design flow rate, the measurement accuracy and control accuracy of the gas flow rate in the system, the reaction efficiency of the ATR, and the heat transfer coefficient of the heat exchanger do not decrease, making it possible to operate the equipment efficiently and stably.

[0110] [Third embodiment] 4A and 4B are schematic diagrams 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 FIGS. 4A and 4B, the ammonia-hydrogen mixed fuel production apparatus 1010C (1010C-1, 1010C-2) of this embodiment is provided with a switching valve (or a three-way valve) 1024 in the reformed gas discharge line L4 between the compressor 1022 and the product tank 1023, and the reformed gas G 12 A buffer tank 1025 is provided to temporarily store the gas when the gas composition is below a predetermined value.

[0111] Then, based on the measurement by the gas component analyzer 1017, the changeover valve (or three-way valve) 1024 is switched to change the reformed gas G 12 The storage location can be changed as needed.

[0112] In the ammonia-hydrogen mixed fuel production apparatus 1010C-1 of this embodiment, as shown in FIG. 4A, when there is a demand operation (turndown operation) of 30% to 100% turndown on the demand side X, the on-off valve V3 is "closed" and the reformed gas G is supplied from the buffer tank. 12 is not sent to the demand side X, and reformed gas G 12 If the hydrogen (H2) concentration in the product tank 1023 satisfies the required H2 concentration, the product gas 1018 is stored in the product tank 1023. Thereafter, the product (H2) 1018 is supplied from the product tank 1023 to the demand unit X.

[0113] In addition, when the demand side X requests low load operation (15% to 30%) with a turndown ratio of less than 30%, the reformed gas G 12 In order to recycle and reform a part of the gas G, as shown in FIG. 4B, the on-off valve V3 is opened, and the recycled gas G is supplied from the buffer tank 1025. 13 The recycle gas G is supplied to the recycle line L6 via the buffer gas line L8. 13 The buffer gas line L8 supplies the buffer gas G 13 An on-off valve V3 is provided for supplying the product gas 1018.

[0114] In this embodiment, the reformed gas G 12 The storage location of the recycled gas can be changed as needed, and during low load operation (15% to 30%) where the turndown ratio is less than 30%, the recycled gas can be supplied from the buffer tank 1025 as shown in FIG. 4B, thereby quickly responding to the demand on the demand side X.

[0115] [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 ATR reactor (hereinafter also referred to as the "reactor") 10 includes a first catalyst section 13 and a second catalyst section 21.

[0116] This first catalyst section 13 is connected to the inlet raw material gas G containing hydrogen. 11 The second catalytic section 21 is for catalytically combusting the ammonia. The second catalytic section 21 is for causing a partial oxidation reaction (exothermic reaction) of the ammonia using oxygen. In the reactor 10A, heat is generated by the combustion of a combustible gas such as hydrogen in the first catalyst section 13. The generated heat-containing gas G 11H However, when the oxygen-containing gas flows into the second catalyst section 21, the second catalyst section 21 is heated. 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 (heating furnace, etc.), and can decompose ammonia (produce hydrogen) with an efficient and simple reactor configuration.

[0117] The reactor 10A has a first catalyst section 13 as a configuration capable of generating a reaction for heating the second catalyst section 21 used for ammonia reforming before the ammonia reforming. This reaction proceeds at the inlet section of 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.

[0118] The reactor 10A comprises a housing 1, which has 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 the flow path 11 formed inside are different, and the inlet 2 and the outlet 3 are narrower than the internal flow path 11 (a portion with a locally expanded cross-sectional area). The flow path 11 is formed between the inlet 2 and the outlet 3. The flow path 11, as will be described in detail later, is provided with a gas G (gas G 11 , G 11H , G 12 ) will be played.

[0119] 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 (for example, a perfect circle when viewed from above). 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 (for example, rectangular in top view).

[0120] The inlet 2 is the inlet raw material gas G 11 This is an opening through which the raw material gas G is introduced into the housing 1 (reactor 10A). 11 is a gas containing ammonia, oxygen, and flammable gases other than ammonia. Therefore, ammonia and flammable gases other than ammonia are introduced into 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.

[0121] 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. Inlet raw material gas G 11 The inlet raw gas G may also contain components used in the combustion of combustible gases and ammonia reforming, such as oxygen. 11 The inlet raw material gas G introduced into the housing 1 may contain gases other than ammonia, flammable gases, and oxygen. 11 is supplied to the first catalyst section 13. The inlet raw material gas G introduced into the first catalyst section 13 11 is the gas G with heat generated by the catalytic reaction 11H Generate.

[0122] The first catalyst section 13 generates a gas G having heat. 11HThe gas G with the generated heat flows out. 11H The generated gas G flows into the second catalyst section 21. 11H is the inlet source gas G 11 The gas G containing the generated heat includes ammonia heated by the heat generated by the combustion of the combustible gas in the first catalytic section 13 and oxygen not used in the first catalytic section 13. 11H may also contain unburned flammable gases.

[0123] The second catalyst section 21 generates the reformed gas G 12 The reformed gas G 12 The reformed gas G flows out from the outlet 3. 12 This is an opening that allows the reformed gas G to flow out from the inside of the housing 1 (reactor 10). 12 is, for example, hydrogen generated in the reactor 10, nitrogen generated along with the hydrogen, and the introduced inlet raw material gas G 11 These are unreacted gases and accompanying gases. 11 , G 11H , G 12 These are collectively called Gas G.

[0124] 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, 1,000 / hr or more and 50,000 / hr or less, preferably 3,000 / hr or more and 30,000 / hr or less. Therefore, as for the size of the reactor 10, if the housing 1 has a cylindrical (approximately cylindrical) shape, the diameter of the housing 1 can be set to, for example, 300 mm or more and 800 mm or less. Furthermore, if the housing 1 has a rectangular shape when viewed from above, the width and depth of the housing 1 can both be set to, for example, 300 mm or more and 800 mm or less.

[0125] 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.

[0126] 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).

[0127] 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.

[0128] The first catalyst section 13 includes a first catalyst. The first catalyst is a catalyst that reacts with the inlet raw material gas G introduced from the inlet 2. 11 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, an inlet raw material gas G containing ammonia and a combustible gas is introduced. 11is 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.

[0129] 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).

[0130] 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. Furthermore, as a flammable gas, the reformed gas G stored in the product tank 1023 (see FIG. 1 etc.) or 1025 (see FIG. 4A) 12 In this case, in order to avoid poisoning of the catalyst by moisture, the reformed gas G 12 Since it is necessary to remove the moisture inside, a moisture removal unit 1026 is installed (see FIG. 1B). The moisture removal unit 1026 removes moisture by a cooling method and by using an adsorbent, thereby preventing the first catalyst unit 13 from being poisoned.

[0131] 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)

[0132] The heat generated by combustion in the first catalytic section 13 is the heat generated by the combustion of the combustible gas. Therefore, the amount of generated heat is the amount of combustion of the combustible gas, that is, the amount of combustion of the inlet raw material gas G 11 Therefore, by providing the first catalyst section 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.

[0133] 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.

[0134] 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.

[0135] 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, for example, 100 mm or more and 200 mm or less.

[0136] 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.

[0137] 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.

[0138] In addition, as shown in FIG. 5A, by providing a first dispersion section 18A between the first catalyst section 13 and the second catalyst section 21, the gas G having heat generated in the first catalyst section 13 can be dispersed. 11H ) can be prevented from being transmitted only to the vicinity directly below the first catalyst portion 13, and can be made to come into uniform and even contact with the entire second catalyst portion 21 arranged below the first catalyst portion 13.

[0139] 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 is configured to direct the heated gas G generated in a direction obliquely downward from the center of the first catalyst section 13. 11H In this case, the heated gas G is blown out not only in the diagonally downward direction but also directly below. 11HAlternatively, a porous plate filled with particulate first catalyst 13 may also serve as first dispersion section 18A. Alternatively, first dispersion section 18A may be separately and independently installed below first catalyst 13.

[0140] 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.

[0141] 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.

[0142] In addition, as shown in FIG. 5D, the second dispersion section 18B of another example is installed between the inlet 2 and the first catalyst section 13, so that the inlet raw material gas G 11 can be dispersed toward the first catalyst portion 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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 the 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 also absorbs the generated heat-bearing gas G 11H It is a catalyst that generates hydrogen from the ammonia contained in

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] Returning to FIGS. 5A and 5D, 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 (12) 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 + 0.25O2 → H2 + 0.5N2 + 0.5H2O Exothermic △H = -75kJ / mol … (12) NH3 + 0.75O2 → 0.5N2 + 1.5H2O Exothermic △H = -317kJ / mol…(13) NH3→1.5H2+0.5N2 endotherm △H=+45.9kJ / mol …(14)

[0152] In particular, hydrogen is produced by the reaction of reaction formula (14), and a hydrogen-containing gas G3 is obtained.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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).

[0157] 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.

[0158] 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.

[0159] 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.

[0160] Reaction conditions: 300Nm 3In the reactor 10 that produces hydrogen at 1000kJ / hr, the first catalyst section 13 used a platinum catalyst (3 mm diameter spheres) in which 2 wt% of platinum was supported on an alumina carrier. The second catalyst section 21 used a honeycomb catalyst (W1 = 150 mm, D1 = 150 mm, H1 = 50 mm) supporting cobalt. The width ratio W2 / W1 was 1, and the thickness ratio T1 / T2 of the heat insulating material was 1. The first catalyst section 13 was located between the inlet 2 and the second catalyst section 21 in a section 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. m The amount of the first catalyst packed was 3 L, and the amount of the second catalyst packed was 40.5 L.

[0161] After hydrogen reduction at 600°C, the inlet raw gas G 11 The flow rates of ammonia and oxygen are 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.

[0162] As shown in FIG. 10, an inlet source gas G containing hydrogen is introduced from the inlet. 11 is introduced into the housing 1 from the inlet 1a at room temperature (for example, 30°C), passes through the heat insulating material 12 area, and reaches the first catalyst section 13. In this first catalyst section (platinum catalyst) 13, hydrogen is combusted to produce the inlet raw material gas G 11 The gas temperature rises. As an example, in FIG. 10, the inlet source gas G introduced at 30° C. 11 As the gas passes through the first catalyst section 13, the temperature starts to rise (from 30°C to 280°C) due to hydrogen combustion, and the gas temperature rises further.

[0163] That is, the inlet raw material gas G 11When hydrogen is introduced and ignited by catalytic combustion in the first catalytic section 13, the heat of combustion of hydrogen causes the temperature in the first catalytic section 13 to rise rapidly from room temperature (30°C).Then, the temperature near the outlet of the first catalytic section 13 reaches a temperature of, for example, about 180°C to 300°C, at which the partial oxidation reaction of ammonia (the reaction shown in reaction formula (2)) that proceeds near the inlet of the second catalytic section 21 in the subsequent stage can proceed.

[0164] The inside of the reactor 10B is insulated by heat insulating materials 12, 22, etc. For example, the gas G having heat generated by the catalytic reaction at a temperature of about 200°C or higher 11H As the second catalyst section 21 is heated by the inflow of the ammonia, the partial oxidation reaction and oxidation reaction of ammonia, which are represented by reaction formulas (12) and (13), proceed near the inlet of the second catalyst section 21. Because these are exothermic reactions, the temperature of the gas G flowing through the second catalyst section 21 further increases, and the temperature of the flowing gas G increases, for example, to 600°C or higher. However, as the gas flows downstream in the second catalyst section 21, the ammonia decomposition reaction (hydrogen production reaction), which is represented by reaction formula (14), becomes dominant. As a result, the temperature of the gas G flowing through the second catalyst section 21 begins to decrease.

[0165] 11 is a graph showing the temperature distribution inside the reactor 10 when the supply of a combustible gas (e.g., hydrogen) is stopped and ammonia reforming is performed in the reactor 10A. The graph shown in FIG. 11 shows the temperature distribution inside the reactor 10 when the inlet raw material gas G containing no hydrogen is reformed using the second catalyst section 21 that has already been heated as shown in the graph of FIG. 11 10 is a graph showing ammonia reforming (without hydrogen).

[0166] In FIG. 10, the temperature of the second catalyst section 21 is already in the heating range of about 600° C. to 700° C., so that the inlet raw material gas G containing, for example, ammonia (but not hydrogen) and having a temperature of about 30° C. (room temperature) 11 When the inlet source gas G (without hydrogen) is introduced, 11 (No hydrogen) passes through the first catalyst section 13 without igniting. And by installing a heat exchanger, the inlet raw gas G 11The inlet raw material gas G (without hydrogen) is introduced into the second catalyst section 21. At this time, although there may be some variation depending on the timing of stopping the hydrogen supply, the introduction temperature is from room temperature or higher to 200°C and the gas flows into the second catalyst section 21. 11 In the case of (no hydrogen), the reaction proceeds due to the second catalyst section 21 heated to about 600°C to 700°C.

[0167] Furthermore, the temperature of the second catalyst section 21 is maintained high in an adiabatic state, and the ammonia decomposition reaction continues by the second catalyst section 21, as shown in FIG. 11, even without the addition of a flammable gas. Depending on the timing of hydrogen stoppage, there may be some fluctuations in the heat exchange in the heat exchanger 1030. 11 The introduction temperature (without hydrogen) ranges from room temperature to 200°C. Two types of temperature plots are shown in Figure 11, but suitable conditions can be set appropriately for the system. Note that the temperature examples are merely examples, and the present invention is not limited to these. In addition, at a relatively early timing after the hydrogen supply is stopped, although there is some fluctuation in the heat exchange in the heat exchanger 1030, the inlet raw material gas G 11 The inlet temperature (without hydrogen) ranges from room temperature to 200°C. Two types of temperature plots are shown in Figure 11, but once the heat exchange with the high-temperature gas at the reactor outlet becomes steady, the temperature reaches 500°C or higher. Note that the temperature shown is merely an example, and the present invention is not limited to this.

[0168] 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 (Figs. 5A and 5D). 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 (introducing step) introduces an inlet raw material gas G containing ammonia and a flammable gas other than ammonia. 11This is a step of introducing a flammable gas (containing hydrogen) into the reactor 10A. This causes the hydrogen to combust in the first catalyst section 13, heating the second catalyst section 21. The amount of flammable 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 flammable gas (such as hydrogen) per mole of ammonia.

[0169] Step S2 (heating step, combustion step) is the inlet raw material gas G 11 This is a step of selectively combusting the combustible gas in the inlet raw material gas G in the first catalyst section 13. 11 This can be done by lighting it on fire.

[0170] 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. There are no particular restrictions on the predetermined temperature, but it is preferable that the predetermined temperature is a temperature at which the reactions of the above reaction formulas (12) to (14) can proceed. In addition, the temperature is raised to the predetermined temperature by, for example, appropriately adjusting the temperature of the inlet raw material gas G 11 This can be done by adjusting the concentration of flammable gases in the

[0171] 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.

[0172] 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) is stopped when the inlet raw material gas G containing ammonia is 11However, the introduction of the flammable gas may be stopped by stopping the introduction of the gas containing ammonia and the flammable gas (hydrogen), and then introducing a gas containing ammonia but not the flammable gas (hydrogen).

[0173] By stopping the introduction of flammable gas, the inlet raw material gas G containing ammonia and oxygen 11 (Gas without hydrogen introduction) does not react in the first catalyst section 13 and is supplied to the second catalyst section 21.

[0174] 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 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 upstream of the second catalytic section 21. Therefore, it is preferable to determine the amount of oxygen in the gas introduced into the reactor 10, taking into consideration the amount of oxygen consumed in both the first catalytic section 13 and the second catalytic section 21.

[0175] The above points can be summarized as follows: In the present disclosure, in the initial process of the step, combustible gas (hydrogen) is ignited in the first catalytic section 13 and platinum catalytic combustion occurs. As a result, the temperature of the second catalytic section 21 rises 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.

[0176] In boilers and heating furnaces that are frequently started and stopped, the reaction gas needs to be preheated to 200°C or higher before each start-up. Conventionally, this required an external heater (such as an electric heater or burner) and required a long time to heat up. Therefore, in the present disclosure, the inlet raw material gas G11 When a combustible gas such as hydrogen and oxygen are added to the (reaction gas), a combustion reaction proceeds in the first catalyst section 13 from room temperature (for example, 30° C.), and the temperature inside the reactor rises (see FIG. 10). This heat generation causes the inlet raw material gas G 11 The temperature in the reactor 10 is raised to a temperature at which the oxidation reaction of ammonia starts in the downstream second catalyst section 21. This eliminates the need for a heating furnace and also speeds up the response to temperature rise. This is because the reaction gas can be heated directly, rather than indirectly from the outside, resulting in a quick response. Then, the gas without hydrogen added was introduced into the inlet gas G 11 By introducing the hydrogen as the hydrogen, the reforming reaction proceeds in the second catalyst section 21.

[0177] 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.

[0178] 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 (1000 kJ / hr), the ratio of the reactor's outer surface area to the catalyst unit volume is large. This makes it easier for heat to radiate, lowering the temperature of the gas G and resulting in a lower ammonia decomposition rate. On the other hand, thickening the insulation material 12 increases the outer diameter of the reactor 10, hindering the compactness of the small-scale device. Alternatively, a large amount of oxygen must be supplied to maintain the temperature equivalent to the heat radiation, resulting in a decrease in the hydrogen yield. Therefore, a honeycomb catalyst is used in this disclosure. With a honeycomb catalyst, no reaction occurs on the outer surface of the honeycomb, so no heat is generated on the surface in contact with the inner surface of the reactor 10 (the surface of the insulation material 12). Furthermore, because the outer wall of the honeycomb is ceramic, the catalyst itself has excellent thermal insulation properties. This allows for both compactness and improved hydrogen yield.

[0179] 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.

[0180] 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.

[0181] 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.

[0182] [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).

[0183] 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.

[0184] 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.

[0185] Even when verified under such experimental conditions, the same effect as in the fifth embodiment (temperature distribution shown in FIG. 10) was obtained.

[0186] [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.

[0187] 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.

[0188] 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.

[0189] The first catalyst section 13 is installed inside the reactor 10, for example, near the inlet 2, to prevent the heat generated by the combustion of the combustible gas from being unintentionally released to the outside, and the gas G having the generated heat supplied to the second catalyst section 21 11H The temperature can be raised to a temperature effective for ammonia reforming (for example, 200°C or higher). This makes it possible to suppress damage to the reactor 10 (particularly the housing 1) due to heat. Furthermore, since ammonia reforming is performed, the reactor 10 can be quickly started up (prepared before ammonia reforming).

[0190] 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.

[0191] 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 also 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.

[0192] 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.

[0193] The method of supporting the first catalyst on the first support 132 is not particularly limited. 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 way, the inlet raw material gas G flowing through the first flow path 131 11 diffuses into the first holder 132, and a catalytic reaction proceeds inside the first holder 132 near the first flow path 131. However, the first catalyst may be supported on, for example, the surface of the first holder 132 so as to face the first flow path 131.

[0194] 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.

[0195] 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).

[0196] 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.

[0197] 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.

[0198] 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.).

[0199] 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.

[0200] 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.

[0201] 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).

[0202] 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.

[0203] 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.

[0204] 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.

[0205] 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.

[0206] 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.

[0207] 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]

[0208] The present invention can be applied to all ammonia-hydrogen mixed fuel production devices. [Explanation of symbols]

[0209] 1010A~1010C Ammonia-hydrogen mixed fuel production equipment 1013 Oxygen supply unit 1014 Raw material supply department 1015 Reforming reactor 1017 Gas Component Analyzer 1018 Fuel 1022 Compressor 1023 Product Tank 1024 Switching valve 1025 Buffer Tank 1026 Moisture removal section 1030 Plate heat exchanger 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) A Confluence L1 ammonia supply line L2 oxygen supply line L3 installation line L4 Reformed gas discharge line L5 product supply line L6 Recycling Line L7 oxygen bypass line L8 buffer gas line G Gas G 11 Inlet raw gas G 11H Gas with generated heat G 12 reformed gas G 13 Recycled Gas V1 on-off valve V3 on-off valve V4 on-off valve V5 on-off valve V 11 Regulating valve V 12 Regulating valve

Claims

1. an oxygen supply unit that supplies oxygen at a desired concentration; a raw material supply unit that supplies ammonia at a desired concentration; a reforming reactor that converts the ammonia into hydrogen using oxygen of a desired concentration from the oxygen supply unit to produce a reformed gas; a combustible gas supply unit that supplies a combustible gas other than the ammonia to the reforming reactor; a gas component analyzer provided in a reformed gas discharge line for discharging the reformed gas from the reforming reactor, the gas component analyzer measuring the concentration of either or both of hydrogen and ammonia in the reformed gas; a plate-type heat exchanger that is provided at an intersection between a raw material supply line that supplies the raw material gas of ammonia and oxygen and a reformed gas discharge line that discharges the reformed gas, and that exchanges heat between the raw material gas and the high-temperature reformed gas; a control device that controls the supply amount of the oxygen to the ammonia, the reforming reactor has a first catalyst and a second catalyst; 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; Furthermore, in the control device, The fuel composition ratio (NH 3 / H 2 ) in the reformed gas is measured by the gas component analyzer to measure the fuel composition required by the demand side, and the oxygen supply amount is controlled based on the measured value obtained by the measurement. The plate-type heat exchanger is used to increase the temperature of the raw material gas introduced into the reforming reactor by heat exchange with the high-temperature reformed gas flowing out from the reforming reactor.

2. a storage tank provided in the reformed gas discharge line for storing the reformed gas; 2. The apparatus for producing ammonia and hydrogen mixed fuel according to claim 1, further comprising a recycle line branching off from the reformed gas discharge line at a branching point, for recycling a portion of the reformed gas to the raw material supply line.

3. 3. The apparatus for producing ammonia and hydrogen mixed fuel according to claim 2, wherein oxygen from the oxygen supply unit is directly introduced into the reforming reactor.

4. 3. The ammonia-hydrogen mixed fuel production apparatus according to claim 1, wherein the oxygen supply unit is an oxygen separation device that separates oxygen from air to a desired concentration.

5. 3. The apparatus for producing ammonia and hydrogen mixed fuel according to claim 1, wherein the oxygen supply unit is an air dryer that removes moisture from the supplied air.

6. 3. The apparatus for producing ammonia-hydrogen mixed fuel according to claim 1, wherein the oxygen supplying unit adds 3 to 20% by volume of oxygen to the amount of the ammonia supplied.

7. 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.

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 that generates heat by burning the combustible gas introduced through the inlet; 2. The ammonia-hydrogen blend fuel manufacturing device according to claim 1, further comprising: a second catalyst portion which is disposed between the first catalyst portion and the outlet, is heated by heat generated in the first catalyst portion, and is an ammonia reforming catalyst which is an NH 3 -ATR catalyst alone or a combination of the NH 3 -ATR catalyst and an NH 3 decomposition catalyst, and which comprises a second catalyst which generates hydrogen from ammonia.

9. The first catalyst portion is disposed between the inlet and the second catalyst portion.

9. The apparatus for producing ammonia and hydrogen mixed fuel according to claim 8.

10. 9. The ammonia-hydrogen blended fuel manufacturing apparatus according to claim 8, wherein the reforming reactor is provided with a dispersion section between the first catalyst section and the second catalyst section, or between the inlet and the first catalyst section, which disperses the gas flowing out from the first catalyst section toward the second catalyst section.

11. an outlet flow path through which the reformed gas containing hydrogen flows out from the outlet; a tank provided in the outlet flow path for storing the outflowed reformed gas containing hydrogen; 9. The ammonia and hydrogen mixed fuel manufacturing device 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 reformed gas containing hydrogen to the inlet.

12. Using the ammonia / hydrogen mixed fuel production apparatus of claim 2, A fuel supply system characterized in that, in the case of low load operation with a turndown ratio of less than 30%, a part of the reformed gas is supplied to the reforming reactor side as recycled gas.

13. Using the ammonia-hydrogen mixed fuel production device of claim 1 or 8, an introduction step of introducing an introduction gas containing ammonia and a combustible gas other than ammonia into the 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 temperatures of the first catalyst and the second catalyst reach 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.

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