Modification treatment equipment

Abstract

To provide a reform processing device capable of quickly raising a temperature of a desulfurizer and a CO transformer during start-up operation while effectively utilizing an existing configuration.SOLUTION: When an operation control section M starts operation from a shutdown state, the operation control section M performs a start-up operation of circulating a warming gas through a compressor D, a heat exchanger W for heating a raw material gas, a desulfurizer P, a reforming reaction tube A, a heat exchanger W for heating the raw material gas, a CO transformer Q, and a steam separation section 19 in the form of returning the warming gas to an upstream side of the compressor D through a return path L10 after being discharged from the steam separation section 19, and thereafter executes a steady operation, and when a temperature of the CO transformer Q rises above a set intermediate temperature at which condensation of steam can be avoided in the start-up operation, executes a steam mixing process of mixing a steam generated by a steam generating heat exchanger J with the warming gas having passed through the desulfurizer P and separating the steam from the warming gas in the steam separation section 19.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a reforming treatment apparatus including: a desulfurizer that desulfurizes a raw material gas supplied by a compressor; a reformer that includes reforming reaction tubes that steam reform the raw material gas from the desulfurizer to produce a reformed gas and reforming burners that heat the reforming reaction tubes; a raw material gas heating heat exchanger that heats the raw material gas with the reformed gas from the reformer; a CO transformer that has a carbon monoxide shift catalyst that transforms carbon monoxide contained in the reformed gas from the raw material gas heating heat exchanger into carbon dioxide to produce a transformed gas and includes a cooling pipe through which cooling water that cools the carbon monoxide shift catalyst flows; a steam generating heat exchanger that heats steam generating water with combustion gas from the reforming burner to produce steam to be mixed with the desulfurized raw material gas; and a steam separation unit that separates steam from the transformed gas. [Background technology]

[0002] In such a reforming treatment device, a raw material gas, which is a hydrocarbon gas such as natural gas or naphtha, is supplied to a desulfurizer for desulfurization, and the desulfurized raw material gas is supplied to a reforming reaction tube in a mixed state with water vapor, whereby the reformer reforms the raw material gas into a reformed gas with a high hydrogen content, and the CO contained in the reformed gas is converted into carbon dioxide in a CO convertor, thereby producing a converted gas with a high hydrogen content and a low carbon monoxide concentration (see, for example, Patent Document 1).

[0003] Although Patent Document 1 omits a detailed description of the CO transformer, the CO transformer is configured to have a carbon monoxide transforming catalyst that transforms carbon monoxide contained in the reformed gas into carbon dioxide, and to have a cooling pipe that flows cooling water that cools the carbon monoxide transforming catalyst (see, for example, Patent Document 2). In other words, since the reaction in the CO transformer to transform carbon monoxide into carbon dioxide is an exothermic reaction, by flowing cooling water through the cooling pipe, the temperature of the CO transformer is maintained at a temperature (for example, 180°C to 190°C) suitable for transforming carbon monoxide into carbon dioxide.

[0004] Incidentally, the converted gas generated in the reforming treatment device is supplied to, for example, a pressure swing adsorption type hydrogen purification device, which adsorbs and removes miscellaneous gases other than the hydrogen component in the converted gas, thereby producing a product gas with a high concentration of hydrogen components. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-335304 [Patent Document 2] Japanese Patent Application Publication No. 9-268001 Summary of the Invention [Problem to be solved by the invention]

[0006] When the reforming treatment device starts operation from a shutdown state in which the supply of raw material gas has been stopped and combustion in the reforming burner has been stopped, the supply of raw material gas to the compressor is stopped and combustion in the reforming burner is started. A start-up operation is performed to heat the desulfurizer, reforming tube, and CO transformer by circulating the heating gas (e.g., hydrogen) through the compressor, raw material gas heating heat exchanger, desulfurizer, reforming reaction tube, raw material gas heating heat exchanger, CO transformer, and steam separation unit in a manner that the heating gas is discharged from the steam separation unit and returned to a location upstream of the compressor, and then steady-state operation is performed in which the compressor supplies raw material gas to the desulfurizer.

[0007] Incidentally, if the internal flow passages of the reforming treatment device are filled with hydrogen gas when the reforming treatment device is stopped, the hydrogen gas is used as a temperature-raising gas for start-up operation. Furthermore, when the reforming treatment device is shut down and stored, if the internal flow paths of the reforming treatment device are filled with an inert gas (e.g., nitrogen gas), a hydrogen gas purging process is performed in which hydrogen gas is supplied to the internal flow paths of the reforming treatment device while the inert gas (e.g., nitrogen gas) is discharged outside the device, and then the hydrogen gas filled in the reforming treatment device is used as a heating gas to perform start-up operation.

[0008] During startup, the reforming tubes can be easily heated quickly by combustion in the reforming burner, but the raw material gas supplied to the desulfurizer is heated by the heating gas in the raw material gas heating heat exchanger, making it difficult to heat the desulfurizer quickly.Furthermore, the CO converter is heated by heating the flowing heating gas after the flow of cooling water through the cooling tubes is stopped, but it also tends to be difficult to heat the CO converter quickly. It is possible to install a heater for startup operation in order to quickly heat up the desulfurizer and CO converter, but this would significantly increase the initial cost and running cost, making it difficult to put into practical use.

[0009] The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a reforming treatment device that can rapidly increase the temperatures of a desulfurizer and a CO transformer during startup operation while effectively utilizing existing configurations. [Means for solving the problem]

[0010] The reforming treatment device of the present invention includes a desulfurizer that desulfurizes a raw material gas supplied by a compressor, a reformer that includes reforming reaction tubes that steam reform the raw material gas from the desulfurizer to produce a reformed gas and a reforming burner that heats the reforming reaction tubes, a raw material gas heating heat exchanger that heats the raw material gas with the reformed gas from the reformer, a CO converter that has a carbon monoxide shift catalyst that shifts carbon monoxide contained in the reformed gas from the raw material gas heating heat exchanger to carbon dioxide to produce a shifted gas and includes a cooling pipe through which cooling water that cools the carbon monoxide shift catalyst flows, a steam generating heat exchanger that heats steam generating water with combustion gas from the reforming burner to produce steam to be mixed with the raw material gas after the desulfurization treatment, and a steam separation unit that separates steam from the shifted gas, and its characteristic configuration is as follows: When starting operation from a stopped state in which the supply of the raw material gas has been stopped and the combustion of the reforming burner has been stopped, the operation control unit stops the supply of the raw material gas to the compressor and continues combustion of the reforming burner, and circulates the temperature-raising gas through the compressor, the raw material gas heating heat exchanger, the desulfurizer, the reforming reaction tube, the raw material gas heating heat exchanger, the CO transformer, and the water vapor separation unit in a manner such that the temperature-raising gas is returned to a location upstream of the compressor through a return path when it is discharged from the water vapor separation unit, thereby A start-up operation is performed to raise the temperatures of the reforming reaction tube and the CO transformer to a set target state, and then a steady operation is performed to start supplying the raw material gas to the compressor and generate the transformed gas. Furthermore, when the temperature of the CO transformer is raised to a set intermediate temperature or higher at which condensation of water vapor can be avoided during the start-up operation, water vapor generated in the water vapor generating heat exchanger is mixed with the temperature-raising gas that has passed through the desulfurizer, and a water vapor mixing process is performed to separate water vapor from the temperature-raising gas in the water vapor separation section.

[0011] That is, when starting operation from a shutdown state in which the supply of raw material gas is stopped and the combustion of the reforming burner is stopped, a startup operation is performed in which the supply of raw material gas to the compressor is stopped and the reforming burner is burning, and the temperature-raising gas is circulated through the compressor, raw material gas heating heat exchanger, desulfurizer, reforming reaction tube, raw material gas heating heat exchanger, CO transformer, and water vapor separation unit, with the temperature-raising gas being discharged from the water vapor separation unit and returned to a location upstream of the compressor through a return line. During the startup operation, when the temperature of the CO transformer rises to a set intermediate temperature or higher that prevents water vapor from condensing, a water vapor mixing process is performed in which the temperature-raising gas that has passed through the desulfurizer is mixed with water vapor generated in the water vapor generation heat exchanger, and the water vapor is separated from the temperature-raising gas in the water vapor separation unit.

[0012] In other words, if condensation occurs in the CO converter, the carbon monoxide conversion catalyst will deteriorate. However, if the temperature of the CO converter is raised to a set intermediate temperature or higher that prevents condensation of water vapor, the water vapor generated in the water vapor generation heat exchanger will be mixed with the heating gas that has passed through the desulfurizer, and a water vapor mixing process will be performed in which the water vapor is separated from the heating gas in the water vapor separation unit.

[0013] When the temperature-raising gas that has passed through the desulfurizer is mixed with the steam generated in the steam-generating heat exchanger, the temperature-raising gas mixed with the steam passes through a reforming reaction tube heated by a reforming burner and then flows to the raw material gas heating heat exchanger and CO transformer, where the raw material gas is heated in the raw material gas heating heat exchanger and the carbon monoxide shift catalyst in the CO transformer is heated. Furthermore, since the heating gas mixed with water vapor has a larger calorific value than the heating gas alone, the amount of heat used to heat the raw material gas in the raw material gas heating heat exchanger and the amount of heat used to heat the carbon monoxide shift catalyst in the CO transformer are increased, and as a result, the desulfurizer and CO transformer can be heated quickly during start-up operation.

[0014] In other words, the existing components, such as the heat exchanger for generating steam, can be effectively utilized while the temperature of the CO transformer can be raised quickly during start-up operation.

[0015] In short, the characteristic configuration of the reforming treatment device of the present invention makes it possible to quickly increase the temperatures of the desulfurizer and CO transformer during start-up operation while effectively utilizing the existing configuration.

[0016] A further characteristic configuration of the reforming treatment device of the present invention is that the operation control unit supplies water from a water supply source to the steam generating heat exchanger and supplies heating steam generated in the steam generating heat exchanger to the cooling pipe from the start-up operation until the temperature of the CO transformer rises to or above the set intermediate temperature.

[0017] That is, when starting operation from a stopped state, startup operation is performed as described above, and from the start of startup operation until the temperature of the CO transformer rises to or exceeds the set intermediate temperature, that is, until the steam mixing process is performed, water from the water supply source is supplied to the steam generating heat exchanger to generate heating steam, and the heating steam is supplied to the cooling pipe of the CO transformer.

[0018] Therefore, when starting up, the CO transformer can be heated not only by the heating gas but also by the heating steam supplied to the cooling pipe, so that the temperature of the CO transformer can be raised quickly when starting up. In other words, the existing components, namely the steam generating heat exchanger and the cooling pipes of the CO transformer, can be effectively utilized, while the temperature of the CO transformer can be raised quickly during start-up operation.

[0019] Incidentally, when the supply of raw material gas to the compressor is started and steady-state operation for generating transformed gas is performed, water from the water supply source is supplied as cooling water to the cooling pipe of the CO transformer, and the water that has flowed through the cooling pipe is supplied to the heat exchanger for generating steam as water for generating steam.

[0020] In short, the characteristic configuration of the reforming treatment device of the present invention makes it possible to quickly raise the temperature of the CO transformer during start-up operation while effectively utilizing the existing configuration.

[0021] A further characteristic configuration of the reforming treatment device of the present invention is that the compressor includes an intercooler between a front compression section and a rear compression section, a main line and a bypass line having a greater passage resistance than the main line are provided in parallel in the return path, a line switching unit is provided that switches between a main line flow state in which the temperature-elevating gas flows through the main line and a bypass line flow state in which the temperature-elevating gas flows through the bypass line, During the startup operation, the operation control unit switches the line switching unit to the main line flow state from the start of the startup operation until the temperature of the CO transformer rises to or above the set intermediate temperature, and after the temperature of the CO transformer rises to or above the set intermediate temperature, switches the line switching unit to the bypass line flow state while stopping cooling of the intercooler.

[0022] That is, during startup operation, the line switching unit is switched to the main line flow state from the start of startup operation until the temperature of the CO2 transformer rises to or above the set intermediate temperature, and after the temperature of the CO2 transformer rises to or above the set intermediate temperature, the line switching unit is switched to the bypass line flow state with intercooler cooling stopped.

[0023] Therefore, when the bypass line flow state is switched to, the pressure of the heating gas flowing through the return line to the upstream side of the compressor decreases, so the amount of compression when the compressor pressurizes the heating gas to the set target pressure increases, causing the heating gas to become hot.Furthermore, because the intercooler cooling is stopped, the heating gas continues to circulate in a hot state, and the heating gas mixed with water vapor becomes hot.

[0024] In other words, when the bypass line flow state is switched to, the circulation flow rate of the heating gas mixed with water vapor decreases, but the temperature of the heating gas mixed with water vapor increases, and the amount of heat used to heat the raw material gas in the raw material gas heating heat exchanger and the amount of heat used to heat the carbon monoxide shift catalyst in the CO transformer increase, and as a result, the desulfurizer and CO transformer can be heated more quickly during startup operation.

[0025] In short, according to this further characteristic configuration of the reforming treatment device of the present invention, the temperatures of the desulfurizer and the CO transformer can be increased more quickly during start-up operation.

[0026] A further characteristic configuration of the reforming treatment device of the present invention is that the reformer is configured to have a reforming furnace having a cylindrical side wall disposed between a ceiling wall and a bottom wall, the reforming burner is provided in a central portion of the ceiling wall in a state in which it burns downward, and the reforming reaction tubes are provided around the reforming burner in a position in which they hang down from the ceiling wall; an exhaust port for exhausting combustion gas from the reforming burner is opened at an upper side portion of the side wall, and a cylindrical outer wall is provided at an outer side portion of the side wall so as to be disposed between the ceiling wall and the bottom wall; the heat exchanger for generating steam is disposed in an external space between the side wall and the outer wall; An external exhaust port is provided at a lower portion of the outer wall, for exhausting the combustion gas of the reforming burner that flows from the exhaust portion through the external space.

[0027] That is, a cylindrical outer wall is provided at the outer side of the side wall of the reforming furnace, positioned between the ceiling wall and the bottom wall, and the combustion gas discharged from the exhaust section flows through the external space between the side wall and the outer wall and is discharged to the outside from the external exhaust port at the lower side of the outer wall. Therefore, by covering the outer side of the side wall of the furnace body with the outer wall and by having the combustion gas flow through the external space between the side wall and the outer wall, it is possible to improve the insulation properties that prevent the heat generated by the combustion of the burner from escaping to the outside of the furnace body, and as a result, it is possible to sufficiently reduce the amount of combustion of the burner while maintaining the catalyst inside the reforming reaction tube at an appropriate reaction temperature.

[0028] Furthermore, since the steam generating heat exchanger is placed in the external space between the side wall and the outer wall where the combustion gas flows, the steam generating heat exchanger and the reforming furnace can be placed more compactly than if they were placed in different locations.

[0029] In short, the characteristic configuration of the reforming treatment device of the present invention makes it possible to sufficiently reduce the amount of combustion in the burner while maintaining the catalyst inside the reforming reaction tube at an appropriate reaction temperature, and furthermore, makes it possible to arrange the steam generating heat exchanger and the reforming furnace in a compact manner.

[0030] A further characteristic configuration of the reforming treatment device of the present invention is that the CO transformer is configured to include a cylindrical transformer body having a reformed gas inlet at one end and a transformed gas outlet after the transformation treatment at the other end, A columnar packing is arranged in a radially central location inside the converter body, from the one end side toward the other end side, and the cooling pipe is arranged spirally in the space outside the packing inside the converter body, and the carbon monoxide conversion catalyst is filled therein.

[0031] That is, columnar packing materials are arranged in the radial center of the cylindrical converter body, facing from one end to the other, and cooling pipes are arranged spirally in the space outside the packing materials inside the converter body, and the carbon monoxide conversion catalyst is filled in the space. Therefore, the entire carbon monoxide conversion catalyst, which converts carbon monoxide contained in the reformed gas into carbon dioxide, can be efficiently cooled to an appropriate temperature by the cooling pipes.

[0032] In other words, if no columnar packings were present, the carbon monoxide conversion catalyst would also be packed in the radial center of the cylindrical converter body. However, the carbon monoxide conversion catalyst packed in the radial center of the converter body would be located in the radial center of the cooling pipes that are spirally arranged inside the converter body, and there is a risk that the cooling pipes will not be able to effectively cool the carbon monoxide conversion catalyst to an appropriate temperature. However, the presence of columnar packings in the radial center of the cylindrical converter body makes it possible to effectively cool the entire carbon monoxide conversion catalyst to an appropriate temperature by the cooling pipes.

[0033] Furthermore, since the entire carbon monoxide shift catalyst can be cooled well to an appropriate temperature by the cooling pipe, the entire reformed gas flowing through the carbon monoxide shift catalyst of the CO transformer can be subjected to a good shift treatment.

[0034] In short, the characteristic configuration of the reforming treatment device of the present invention makes it possible to perform good transformation treatment on the entire reformed gas flowing through the carbon monoxide transformation catalyst of the CO transformer. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is a schematic diagram of a hydrogen production device. [Figure 2] FIG. 10 is a diagram showing the gas flow state during startup operation (early stage). [Figure 3] FIG. 10 is a diagram showing the gas flow state during startup operation (later stage). [Figure 4] Diagram showing the flow of pure water in startup operation mode (first half) [Figure 5]10A and 10B are diagrams showing the flow state of pure water in the startup operation mode (later stage) and in steady operation. [Figure 6] FIG. 2 is a longitudinal sectional front view showing a CO transformer. [Figure 7] FIG. 2 is a longitudinal sectional front view showing a reformer furnace. [Figure 8] FIG. 2 is a plan view showing an arrangement of reaction tubes in a reformer. [Figure 9] FIG. 2 is a partially omitted longitudinal sectional front view showing a reforming reaction tube. [Figure 10] FIG. 10 is a schematic configuration diagram of a hydrogen production device according to another embodiment. [Figure 11] FIG. 10 is a diagram showing a gas flow state during start-up operation (early stage) in another embodiment. [Figure 12] FIG. 10 is a diagram showing a gas flow state during startup operation (later stage) in another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0036] [Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0037] (Overall configuration of hydrogen production equipment) The hydrogen production device 100 will be described with reference to Figure 1. Note that Figure 1 illustrates steady-state operation in which hydrogen purification operation is being performed. In the figure, flow paths through which various gases, such as raw material gas G, flow are indicated by thick lines, and flow paths through which various gases do not flow are indicated by thin lines. Furthermore, with regard to valves that open and close flow paths, those in an open state are indicated by white outlines, and those in a closed state are indicated by black outlines. The same applies to Figure 2, which shows the state in which the early stage of startup operation is being performed, Figure 3, which shows the state in which the late stage of startup operation is being performed, Figure 4, which shows the flow state of pure water in the early stage of startup operation mode, and Figure 5, which shows the flow state of pure water in the late stage of startup operation mode and steady operation mode.

[0038] The hydrogen production device 100 is equipped with a reforming section R (an example of a reforming treatment device) and a pressure swing adsorption type hydrogen separation section 20 that adsorbs and removes impurities (miscellaneous gases) contained in the converted gas supplied from the reforming section R, thereby purifying the product gas with a high hydrogen concentration. The operation control unit M is configured to control the operation of the reforming unit R and the hydrogen separation unit 20.

[0039] (Details of the reforming section) The reforming section R includes a desulfurizer P that desulfurizes raw material gas G, which is a hydrocarbon gas supplied under pressure by a compressor D; a reformer H to which the desulfurized raw material gas G is supplied in a mixed state with water vapor; a CO converter Q that converts carbon monoxide contained in the reformed gas K (see Figure 7) produced in the reformer H into carbon dioxide to produce a converted gas; a raw material gas heating heat exchanger W that heats the raw material gas G supplied to the desulfurizer P with the reformed gas K from the reformer H; and a steam generation heat exchanger J that generates steam to be mixed with the desulfurized raw material gas G. A raw material gas valve V1 is provided upstream of the compressor D to turn on and off the supply of the raw material gas G and adjust the amount of the raw material gas G supplied.

[0040] The raw material gas G compressed by the compressor D is supplied to the desulfurizer P through the first flow path L1 and via the raw material gas heating heat exchanger W. The desulfurizer P is filled with a desulfurization catalyst such as a Ni-Mo-based or ZnO-based catalyst, and is configured to remove sulfur components such as odorants from the raw material gas G by the desulfurization catalyst. The desulfurized raw material gas G is supplied to the reformer H through the second flow path L2. Steam generated in the steam generating heat exchanger J is supplied to the second flow path L2, and the steam is mixed with the raw material gas G flowing through the second flow path L2.

[0041] The reformer H is configured to heat the reforming reaction tube A (see Figure 9) by combustion of the reforming burner B, and to generate reformed gas K by steam reforming the raw material gas G mixed with steam. 1, the configuration of the reformer H is shown in outline, and the configuration for supplying combustion air to the reforming burner B is omitted.

[0042] The reformed gas K obtained in the reformer H is supplied through the third flow path L3 to the CO converter Q, which reacts the carbon monoxide in the reformed gas with steam, after passing through the raw gas heating heat exchanger W. The CO converter Q is filled with a carbon monoxide conversion catalyst Z (see Figure 6), and the carbon monoxide in the reformed gas reacts with steam to be converted into hydrogen and carbon dioxide. As a result of the reaction in the CO transformer Q, the reformed gas K becomes a transformed gas containing hydrogen, carbon monoxide, carbon dioxide, and methane (with a hydrogen concentration of 64 to 96% by volume). The desulfurization reaction in the desulfurizer P is an endothermic reaction, and the CO transformation reaction in the CO transformer Q is an exothermic reaction.

[0043] (Regarding the flow of metamorphic gas) The converted gas discharged from the CO transformer Q is cooled by heat exchange with cooling water in the cooling water heat exchanger 18 while flowing through the fourth flow path L4, and the water vapor is liquefied. The moisture (water vapor) is removed by the water vapor separation section 19, and the converted gas is then led to the hydrogen separation section 20 through the fifth flow path L5. The fifth flow path L5 is provided with a shift gas valve V5 that opens and closes the fifth flow path L5.

[0044] A return line L10 that returns the gas discharged from the water vapor separation section 19 to a location upstream of the compressor D, bypassing the PSA unit 22, is branched off from the fifth flow path L5. The return line L10 is provided with a return valve V10 that opens and closes the return line L10.

[0045] Although not shown in the figure, a desulfurization treatment return line is provided to return the converted gas from which moisture has been removed in the water vapor separation section 19 to the upstream side of the compressor D for desulfurization treatment in the desulfurizer P, and a desulfurization treatment opening / closing valve is provided to open and close this desulfurization treatment return line. The desulfurization treatment on-off valve is opened during hydrogen refining operation (steady operation) and is closed at other times.

[0046] In addition, a pure water heat exchanger 26 is provided upstream of the cooling water heat exchanger 18 in the fourth flow path L4, which exchanges heat between the converted gas and pure water supplied by a pure water supply pump 25 from a pure water tank 24 (an example of a water supply source) that stores pure water for generating steam. Further, an exhaust path L12 that discharges the gas flowing through the fifth flow path L5 to the outside is branched off from the fifth flow path L5. An exhaust valve V12 that opens and closes the exhaust path L12 is provided in the exhaust path L12.

[0047] Incidentally, the first flow path L1, the second flow path L2, the third flow path L3, the fourth flow path L4, and the return path L10 are used to return the gas discharged from the steam separation section 19 to a location upstream of the compressor D, so that a closed circulation path C can be formed that circulates the gas via the compressor D, the heat exchanger W for heating raw gas, the desulfurizer P, the reformer H, the heat exchanger W for heating raw gas, the CO converter Q, and the steam separation section 19 (see Figure 2).

[0048] (Details of the hydrogen separation section) The hydrogen separation section 20 includes a pressure swing adsorption PSA unit 22 that separates impurities (miscellaneous gases) other than hydrogen contained in the converted gas converted by the CO converter Q to purify a product gas having a high concentration of hydrogen gas, a product tank 23 that stores the purified product gas, and an off-gas tank 21 that stores the off-gas discharged from the PSA unit 22.

[0049] The PSA unit 22 is equipped with a plurality of (three in this embodiment) adsorption towers 20a, 20b, and 20c. Each of the adsorption towers 20a, 20b, and 20c is filled with a combination of adsorbents such as zeolite adsorbent, activated carbon, and silica gel to adsorb miscellaneous gases. Each of the adsorption towers 20a, 20b, and 20c is configured to purify a product gas with a high concentration of hydrogen gas by performing the adsorption step, depressurization step, purge step, and pressurization step (PSA process) at different phases in the multiple adsorption towers 20a, 20b, and 20c.

[0050] Although detailed explanation will be omitted, the above-mentioned process (PSA method process) is sequentially carried out by the operation control unit M by opening and closing multiple valves (not shown) provided in each flow passage connected to multiple adsorption towers 20a, 20b, and 20c. FIG. 1 shows a state in which the adsorption tower 20a is performing an adsorption step in which the converted gas is passed through the adsorption tower 20a to obtain a product gas.

[0051] The product gas purified by the PSA device 22 is supplied to the product tank 23 through the sixth flow path L6, and the product gas stored in the product tank 23 is stably supplied to the hydrogen usage location. The sixth flow path L6 is provided with a product gas valve V6 that opens and closes the sixth flow path L6. The off-gas (miscellaneous gas) from which hydrogen has been separated in the PSA device 22 is supplied to the off-gas tank 21 through a seventh flow path L7. The seventh flow path L7 is provided with an off-gas valve V7 that opens and closes the seventh flow path L7.

[0052] The off-gas stored in the off-gas tank 21 contains combustible gases such as methane and hydrogen, and is therefore led to the fuel gas supply unit 10 via the off-gas flow passage L8, and is supplied from the fuel gas supply unit 10 to the reforming burner B as fuel gas. The off-gas flow passage L8 is provided with an off-gas return valve V8 that opens and closes the off-gas flow passage L8. Although FIG. 1 shows only the flow of the product gas, there are times when the delivery of the product gas and the delivery of the off-gas are carried out simultaneously to the different adsorption towers 20a, 20b, and 20c.

[0053] Incidentally, in order to perform a hydrogen purging process, which will be described later, a hydrogen supply line L11 is provided for supplying hydrogen gas from the product tank 23 to the return line L10. The hydrogen supply passage L11 is provided with a hydrogen gas valve V11 that opens and closes the hydrogen supply passage L11.

[0054] (Details of hydrogen purification operation) As shown in FIG. 1, in hydrogen purification operation (steady operation), raw material gas G passes through raw material gas valve V1, is compressed by compressor D, flows through first flow path L1, and passes through raw material gas heating heat exchanger W before being introduced to desulfurizer P for desulfurization. Then, raw material gas G mixed with water vapor is introduced to reformer H for steam reforming to produce reformed gas K. The reformed gas K is transformed in CO transformer Q, and the transformed gas is cooled in pure water heat exchanger 26 and cooling water heat exchanger 18. After water vapor (moisture) is removed in water vapor separation section 19, the reformed gas is introduced into hydrogen separation section 20 through fifth flow path L5, and product gas (hydrogen gas) is purified.

[0055] (Overall structure of reformer) As shown in FIG. 7, the reformer H reforms a hydrocarbon-based raw material gas G, such as natural gas or naphtha, into a reformed gas K having a high hydrogen content by steam reforming, and includes a reforming reaction tube A and a reforming furnace 2 equipped with a reforming burner B for heating the reforming reaction tube A.

[0056] The reformer 2 is configured to include a ceiling wall 2U, a bottom wall 2D, and a cylindrical side wall 2S disposed between the ceiling wall 2U and the bottom wall 2D. A reforming burner B is provided in the center of the ceiling wall 2U of the reformer H so as to burn downward, and an exhaust section 2E for exhausting combustion gas E from the reforming burner B is opened at an upper portion of the side wall 2S.

[0057] As shown in Figures 7 and 8, a plurality of reforming reaction tubes A are provided in a position that hangs down from the ceiling wall 2U of the reformer H and are arranged side by side at intervals along the periphery of the reforming burner B. In this embodiment, four reforming reaction tubes A are provided as the plurality of reforming reaction tubes A, but three, five or more reforming reaction tubes A may be provided.

[0058] As shown in FIG. 7, a cylindrical outer wall 2G is provided at an outer location of the side wall 2S of the reformer H, in a state where it is disposed between the ceiling wall 2U and the bottom wall 2D. A heat exchanger J for generating steam is disposed in the external space F between the side wall 2S and the outer wall 2G, and generates steam to be mixed with the raw material gas G supplied to the upper part of the reforming reaction tube A. An external discharge port 2Z is ​​provided at a lower portion of the outer wall 2G, and discharges the combustion gas E flowing through the external space F from the discharge section 2E.

[0059] Furthermore, as shown in FIG. 7, an air preheating heat exchanger N that preheats the combustion air AR to be supplied to the reforming burner B is provided between the steam generation heat exchanger J in the external space F and the outer wall 2G.

[0060] (Details of the reaction tube) As shown in FIG. 9, the reforming reaction tube A comprises an outer tube 3 with a closed bottom and an inner tube 4 placed inside the outer tube 3, with the inner tube 4 being formed with an open bottom, and a filling section filled with granular reforming catalyst S is formed between the outer tube 3 and the inner tube 4 in an orientation facing in the vertical direction. The upper end portion of the outer pipe 3 is supported by the ceiling wall 2U of the reformer H in a state where it penetrates the ceiling wall 2U, and the upper end portion of the inner pipe 4 is supported by the upper pipe wall 3u of the outer pipe 3 in a state where it penetrates the upper pipe wall 3u.

[0061] Between the outer pipe 3 and the inner pipe 4, a porous catalyst support portion T for receiving and supporting the reforming catalyst S is provided. The catalyst support portion T is formed with a flow hole that allows the reformed gas K flowing between the outer tube 3 and the inner tube 4 toward the bottom side of the outer tube 3, and is supported at the lower end of the inner tube 4. Incidentally, in Figure 9, the catalyst support part T is shown as being in the form of a porous plate with flow holes formed all over it, but the catalyst support part T can be configured in various forms, such as a plate with flow holes lined up in a row along the circumferential direction, as long as it has flow holes that can receive the reforming treatment catalyst S and allow the reformed gas K to flow through.

[0062] 7 and 9, a raw material gas inlet pipe 5a for introducing raw material gas G mixed with water vapor is connected to a portion of the outer pipe 3 that protrudes from the ceiling wall 2U of the reformer H. This raw material gas inlet pipe 5a is connected to an annular raw material gas distribution pipe 5b, as shown in Fig. 7, and a raw material gas pipe 5 for supplying raw material gas G mixed with water vapor is connected to this raw material gas distribution pipe 5b. In other words, the raw gas G mixed with water vapor is supplied from the raw gas pipe 5 to the annular raw gas distribution pipe 5b, and the raw gas G mixed with water vapor is supplied from the annular raw gas distribution pipe 5b to multiple reforming reaction tubes A.

[0063] As shown in FIG. 7, the raw material gas pipe 5 is supplied with steam generated in a steam generating heat exchanger J, as will be described later, and the raw material gas G and the steam are mixed and supplied to the outer pipe 3 through the raw material gas pipe 5.

[0064] 7 and 9, an exhaust pipe 6a for discharging the reformed gas K is connected to a portion of the inner pipe 4 that protrudes from the outer pipe 3. As shown in Fig. 7, this exhaust pipe 6a is connected to an annular junction pipe 6b, and a guide pipe 6 for guiding the reformed gas K is connected to this junction pipe 6b. That is, the reformed gas K is discharged from the reforming reaction tube A through the discharge tube 6a, and flows toward the CO transformer Q through the guide tube 6 via the annular junction tube 6b.

[0065] (Details of the heat exchanger for steam generation) As shown in FIG. 7, the steam generating heat exchanger J is configured in such a manner that heat transfer tubes 7 are arranged in a spiral shape along the outer periphery of the side wall 2S of the reformer H. That is, a pure water inlet pipe section 7a through which pure water is supplied is formed at the lower end of the heat transfer pipe 7, and a water vapor outlet pipe section 7b through which water vapor is supplied to the raw material gas pipe 5 is formed at the upper end of the heat transfer pipe 7.

[0066] Therefore, the heat exchanger J for generating steam is configured to generate steam by causing pure water supplied to the pure water inlet pipe section 7a to flow through the inside of the heat transfer pipe 7 which is heated by the combustion gas flowing in the external space F, and then configured to supply the generated steam to the raw material gas pipe 5 through the steam outlet pipe section 7b. Furthermore, a branch pipe 7c is connected to the steam discharge pipe section 7b, which supplies the generated steam to the CO transformer Q as heating steam U in the early stage of the start-up operation described below.

[0067] (Details of the air preheating heat exchanger) As shown in FIGS. 7 and 8, the air preheating heat exchanger N is configured in a cylindrical shape that allows air to flow between a cylindrical inner wall 8n and a cylindrical outer wall 8g. An air introduction section 8d is provided below the air preheating heat exchanger N to introduce combustion air AR supplied from a blower (not shown). A plurality of air supply pipes 9 connecting the upper side of the air preheating heat exchanger N and the reforming burner B are provided inside the ceiling wall 2U of the reformer H, arranged radially around the periphery of the reforming burner B.

[0068] Therefore, the air preheating heat exchanger N is configured to heat the combustion air supplied to the air inlet 8d to a high temperature by flowing it between the inner wall 8n and the outer wall 8g, which are heated by the combustion gas flowing in the external space F, and then to supply the combustion air heated to a high temperature to the reforming burner B through the air supply pipe 9.

[0069] Although the detailed configuration of the reforming burner B is omitted, in addition to being connected to an air supply pipe 9, the reforming burner B is also connected to a fuel supply pipe 10a (see Figure 1) connected to a fuel gas supply unit 10, and is configured to combust the fuel gas supplied from the fuel gas supply unit 10 with combustion air supplied through the air supply pipe 9.

[0070] The fuel gas supply unit 10 supplies off-gas from an off-gas tank 21 (see FIG. 1) as fuel gas, and when there is a shortage of off-gas, it supplies raw material gas G as fuel gas. Therefore, although a detailed description will be omitted, the fuel gas supply unit 10 is configured to include a supply amount adjustment valve that adjusts the supply amount of off-gas and raw material gas G. Moreover, the blower (not shown) that blows the combustion air AR to the air introduction portion 8d is configured so that the amount of air supply can be adjusted by adjusting the output.

[0071] (CO transformer details) As shown in FIG. 6, the CO converter Q has a carbon monoxide conversion catalyst Z that converts carbon monoxide contained in the reformed gas K into carbon dioxide, and is equipped with a cooling pipe 11 that flows cooling water to cool the carbon monoxide conversion catalyst Z. That is, the CO transformer Q is configured to include a cylindrical transformer body 12 having a reformed gas inlet 12a at one end and a transformed gas outlet 12b after transformation treatment at the other end. A columnar packing 13 is arranged in the radial center of the inside of the furnace body 12, extending from one end to the other end, and in the space outside the packing 13 inside the furnace body 12, a cooling pipe 11 is arranged spirally from one end to the other end and is filled with a carbon monoxide conversion catalyst Z. The filler 13 is made of, for example, a cylindrical iron pipe.

[0072] More specifically, the converter main body 12 includes a cylindrical main body portion 12A with a bottom, and a reformed gas receiving portion 12B that is flange-connected to the top of the main body portion 12A. The reformed gas receiving portion 12B is configured as a cylindrical portion into which the reformed gas K is introduced through the third flow path L3 and which discharges the introduced reformed gas K toward the main body portion 12A.

[0073] At an upper portion inside the main body portion 12A, for example, a porous frame 14 that is formed to be porous and has air permeability is disposed in a state in which it closes the upper end of the packing 13. In addition, a cylindrical gas receiver 15 that forms a plurality of reformed gas inlets 12a in the circumferential direction is provided at a portion corresponding to the upper portion of the packing 13 in a state in which it communicates with the reformed gas receiving portion 12B and has its lower end portion inserted into the porous frame 14. Therefore, the reformed gas K that flows from the reformed gas receiving section 12B to the gas receiving body 15 is discharged from the reformed gas inlet 12a, and the reformed gas K flows through the porous frame 14 into the outer space of the packing 13.

[0074] A receiving plate 16 for receiving the carbon monoxide conversion catalyst Z is provided at a lower portion inside the main body portion 12A at a position corresponding to the lower end of the filler 13, with the portion facing the filler 13 being non-porous and the portion located outside the filler 13 being porous. The space below the receiving plate 16 is filled with metallic spheres 16a, and the transformed gas in the space below is discharged from the transformed gas outlet 12b to the fourth flow path L4.

[0075] (About the pure water flow state switching unit) As shown in Fig. 5, the system is configured to be switchable between a startup operation mode (later period) in which water (pure water) from a pure water tank 24 (an example of a water supply source) is supplied to the cooling pipe 11 as cooling water, and the water (pure water) after flowing through the cooling pipe 11 is supplied to the steam generating heat exchanger J as water for generating steam, and a startup operation mode (early period) in which water (pure water) from the pure water tank 24 (an example of a water supply source) is supplied to the steam generating heat exchanger J to generate heating steam U, and the heating steam U is supplied to the cooling pipe 11, as shown in Fig. 4. The startup operation mode (later period) shown in Fig. 5 is the same as the steady operation mode.

[0076] To further explain, as shown in Figure 5, in the steady-state operation mode and the startup operation mode (later stage), a first pure water supply path L13 is provided to allow pure water supplied by the pure water supply pump 25 to flow to the inlet portion of the cooling pipe 11, and a second pure water supply path L14 is provided to allow pure water discharged from the outlet portion of the cooling pipe 11 to flow to the pure water introduction pipe portion 7a of the heat transfer pipe 7.

[0077] Also, as shown in Figure 4, in the startup operation mode (early stage), a third pure water supply path L15 is provided that branches off from the first pure water supply path L13 and merges with the second pure water supply path L14, causing the pure water flowing through the first pure water supply path L13 to bypass the cooling pipe 11 and flow into the pure water inlet pipe section 7a of the heat transfer pipe 7. In addition, in the startup operation mode (early stage), a steam flow path L16 is provided in a state where it merges with the first pure water supply path L13, and causes the water vapor discharged from the branch pipe 7c branching off from the water vapor discharge pipe section 7b in the heat transfer pipe 7 to flow to the inlet portion of the cooling pipe 11 as heating steam U.

[0078] Furthermore, a steam discharge path L17 is provided branching off from the second pure water supply path L14, which allows the steam discharged from the outlet of the cooling pipe 11 to flow into the pure water tank 24. The steam discharge path L17 is provided with a steam cooling heat exchanger 27 which cools and condenses the steam with cooling water. Although detailed description is omitted, the pure water tank 24 is equipped with a pure water device such as an ion exchange type that purifies the condensed water that returns through the steam exhaust line L17.

[0079] In addition, a first on-off valve 28 is provided downstream of the branch point of the third pure water supply line L15 in the first pure water supply line L13, and a second on-off valve 29 is provided near the inlet of the cooling pipe 11 in the steam flow path L16. A third on-off valve 30 is provided downstream of the branch point of the second pure water supply line L14 to the steam discharge line L17, and a fourth on-off valve 31 is provided in the steam discharge line L17.

[0080] Therefore, by opening the first on-off valve 28 and the third on-off valve 30 and closing the second on-off valve 29 and the fourth on-off valve 31, the operation mode can be switched to the steady-state operation mode and the startup operation mode (later stage), and by closing the first on-off valve 28 and the third on-off valve 30 and opening the second on-off valve 29 and the fourth on-off valve 31, the operation mode can be switched to the startup operation mode (early stage).

[0081] Incidentally, in this embodiment, the pure water flow state switching unit Y, which switches the flow state of pure water from the pure water tank 24 between a steady operation mode, a startup operation mode (later period), and a startup operation mode (early period), is configured with the first opening / closing valve 28, the second opening / closing valve 29, the third opening / closing valve 30, and the fourth opening / closing valve 31 as its main parts. The first on-off valve 28, the second on-off valve 29, the third on-off valve 30, and the fourth on-off valve 31 are controlled to open and close by an operation control unit M.

[0082] (Details of stop operation) When the hydrogen purification operation is stopped and the production of hydrogen gas is suspended for a long period of time (for example, for longer than several days), a hydrogen purging process, a water vapor exhaust process, and a hydrogen filling process are carried out in this order. That is, when hydrogen purification operation is stopped, first, the compressor D continues to operate, while the mixing (supply) of steam and the heating of the reformer H by the reforming burner B are continued, and the raw gas valve V1, the shift gas valve V5, and the return valve V10 are closed, and the hydrogen gas valve V11 and the exhaust valve V12 are opened to perform a hydrogen purge process in which the product gas (hydrogen gas) is supplied to the closed circulation path C. This hydrogen purge process causes the product gas (hydrogen gas) to flow through the closed circulation path C, and the gas remaining in the closed circulation path C is discharged through the exhaust path L12, while the inside of the closed circulation path C is replaced with the product gas (hydrogen gas).

[0083] Next, while continuing to operate compressor D, the mixing (supply) of steam is stopped, the heating of reformer H by reforming burner B is stopped, hydrogen gas valve V11 and exhaust valve V12 are opened, and return valve V10 is closed, thereby causing the product gas (hydrogen gas) filled in closed circuit C to flow through closed circuit C, thereby performing a steam discharge process to discharge the steam inside closed circuit C.

[0084] Thereafter, compressor D is stopped, the continued mixing (supply) of steam is stopped, the continued heating of reformer H by reforming burner B is stopped, and the hydrogen gas valve V11 and exhaust valve V12 are closed, and a hydrogen filling process is performed in which product gas (hydrogen gas) is filled inside closed circulation path C. In addition, although not shown in the figure, a pressure sensor is provided to detect the internal pressure of the closed circuit C, and when the internal pressure of the closed circuit C drops, the hydrogen gas valve V11 is opened to replenish the product gas (hydrogen gas). Although a detailed description will be omitted, when shutdown operation is performed, a hydrogen filling process is carried out in which product gas (hydrogen gas) is supplied to the adsorption towers 20a, 20b, and 20c of the PSA unit 22 to fill them.

[0085] (Regarding start-up operation) When starting operation from a shutdown state in which the supply of raw material gas G has been stopped and the combustion of the reforming burner B has been stopped, the operation control unit M performs startup operation (see Figures 2 and 3) and then starts supplying raw material gas G to the compressor D to perform steady-state operation (Figure 1) to generate transformed gas.

[0086] During startup operation, the supply of raw material gas G to compressor D is stopped and reforming burner B is burning. When the temperature-raising gas (hydrogen gas filled in closed circulation path C) is discharged from steam separation section 19, it is returned to a location upstream of compressor D through return path L10. This gas is circulated through compressor D, raw material gas heating heat exchanger W, desulfurizer P, reforming reaction tube A, raw material gas heating heat exchanger W, CO transformer Q, and steam separation section 19, thereby raising the temperatures of desulfurizer P, reforming reaction tube A, and CO transformer Q to the set target state.

[0087] That is, with the raw material gas valve V1, shift gas valve V5, hydrogen gas valve V11, and exhaust valve V12 closed, operation of compressor D is started, heating of reformer H by reforming burner B is started, and the product gas (hydrogen gas) filled as a temperature-raising gas is caused to flow through closed circuit C, while the temperature of desulfurizer P, reforming reaction tube A, and CO transformer Q is raised. At this time, the hydrogen gas valve V11 is opened and product gas (hydrogen gas) is replenished, thereby increasing the internal pressure of closed circuit C.

[0088] In this embodiment, the startup operation consists of a startup operation (early stage) until the temperature of the CO transformer Q rises to a set intermediate temperature (e.g., 140°C) or higher at which condensation of water vapor can be avoided, and a startup operation (later stage) after the temperature of the CO transformer rises to a set intermediate temperature (e.g., 140°C) or higher at which condensation of water vapor can be avoided.

[0089] When the start-up operation is performed, the outlet pressure of the compressor D is adjusted to a target pressure (for example, 0.8 MPa), and the internal pressure of the closed circuit C is maintained at a high pressure. Incidentally, the set target state is, for example, a state in which the temperature of the reforming treatment catalyst S is 720°C or higher, the inlet temperature of the reforming reaction tube A is 200°C or higher, the lower temperature of the desulfurizer P is 210°C or higher, and the lower temperature of the CO transformer Q is 170°C or higher.

[0090] As shown in Figure 2, in the startup operation (early stage), the heating gas (hydrogen gas filled in the closed circulation path C) is circulated in such a way that when it is discharged from the water vapor separation section 19, it is returned to a location upstream of the compressor D through the return path L10, while the pure water flow state switching section Y is switched to the startup operation mode (early stage) (see Figure 4). In other words, the pure water from the pure water tank 24 is supplied to the steam generating heat exchanger J, and the temperature-raising steam U generated in the steam generating heat exchanger J is supplied to the cooling pipe 11 of the CO transformer Q.

[0091] As shown in Figure 3, in the startup operation (later stage), the heating gas (hydrogen gas filled in the closed circulation path C) is circulated in such a way that when it is discharged from the water vapor separation section 19, it is returned to a location upstream of the compressor D through the return path L10, while the pure water flow state switching section Y is switched to the startup operation mode (later stage) (see Figure 5). Therefore, the system is configured so that the water vapor generated in the water vapor generation heat exchanger J is mixed with the temperature-raising gas after passing through the desulfurizer P, and a water vapor mixing process is performed in which the water vapor is separated from the temperature-raising gas in the water vapor separation section 19.

[0092] Thereafter, when the temperatures of the desulfurizer P, the reformer H, and the CO transformer Q reach the set target state, the operation control unit M switches the pure water flow state switching unit Y to the steady-state operation mode, and starts supplying the raw material gas G to perform steady-state operation to generate the transformed gas. That is, the raw material gas valve V1 and the shifted gas valve V5 are opened, and the return valve V10 is closed to generate a shifted gas, which is then supplied to the PSA unit 22. Although detailed explanation will be omitted, after resuming operation, the PSA device 22 will discharge the purified product gas until the hydrogen concentration of the purified product gas reaches or exceeds a set value, and once the hydrogen concentration of the purified product gas reaches or exceeds the set value, the purified product gas will be stored in the product tank 23.

[0093] (Standby operation details) Incidentally, when the hydrogen refining operation is temporarily stopped and the production of hydrogen gas is temporarily stopped (for example, for several hours), a standby operation is performed. In other words, the operation control unit M performs standby operation in which the product gas (hydrogen gas) filled in the closed circuit C is circulated through the closed circuit C via the compressor D, desulfurizer P, reformer H, and CO converter Q, while continuing to heat the reformer H with the reforming burner B.

[0094] To explain further, when switching from hydrogen purification operation to standby operation, first, while continuing to operate compressor D and continuing to mix (supply) steam and heat reformer H with reforming burner B, raw gas valve V1, shift gas valve V5, and return valve V10 are closed, and hydrogen gas valve V11 and exhaust valve V12 are opened to perform a hydrogen purge process in which product gas (hydrogen gas) is supplied to closed circulation circuit C. This hydrogen purge process causes the product gas (hydrogen gas) to flow through the closed circulation path C, and the gas remaining in the closed circulation path C is discharged through the exhaust path L12, while the inside of the closed circulation path C is replaced with the product gas (hydrogen gas).

[0095] Thereafter, while continuing to operate compressor D and continuing to heat reformer H with reforming burner B, the mixing (supply) of steam is stopped, and the hydrogen gas valve V11 and exhaust valve V12 are closed, and the return valve V10 is opened, thereby performing standby operation in which the product gas (hydrogen gas) filled in closed circulation circuit C is circulated through closed circulation circuit C.

[0096] Although detailed description will be omitted, when standby operation is performed, a hydrogen substitution process is performed in which product gas (hydrogen gas) is supplied to and filled into the adsorption towers 20a, 20b, and 20c of the PSA unit 22.

[0097] When transitioning from standby operation to hydrogen purification operation, first, compressor D is continuously operated, and while the reformer H is continuously heated by reforming burner B, mixing (supply) of steam is started, and the raw gas valve V1 and the converted gas valve V5 are opened, and the return valve V10 is closed so that the converted gas is supplied to the PSA unit 22. Although detailed explanation will be omitted, after resuming operation, the PSA device 22 will discharge the purified product gas until the hydrogen concentration of the purified product gas reaches or exceeds a set value, and once the hydrogen concentration of the purified product gas reaches or exceeds the set value, the purified product gas will be stored in the product tank 23.

[0098] [Another embodiment] Next, another embodiment will be described. This embodiment shows a different form of startup operation from the above embodiment, and in order to avoid redundant explanation, configurations that are different from the above embodiment will be described, and explanations of configurations that are the same as the above embodiment will be omitted.

[0099] As shown in FIG. 10, a compressor D is configured to include an intercooler 34 between a front compression section 33A and a rear compression section 33B. Cooling water flows through the intercooler 34, but a cooling water stop valve 35 is provided to stop the flow of cooling water. Therefore, the intercooler 34 is configured to be freely switched between a cooling operating state and a cooling stopped state by opening and closing the cooling water stop valve 35.

[0100] A main line Lm and a bypass line Lb having a higher passage resistance than the main line Lm are installed in parallel in the return line L10, and a line switching unit 36 ​​is provided to switch between a main line flow state in which the temperature-rise gas flows through the main line Lm and a bypass line flow state in which the temperature-rise gas flows through the bypass line Lb.

[0101] That is, the main line Lm is provided with a main line opening / closing valve 36a that opens and closes the main line Lm, and the bypass line Lb is provided with a bypass line opening / closing valve 36b that opens and closes the bypass line Lb and provides passage resistance when in the open state. Therefore, the main line flow state is realized by opening the main line opening / closing valve 36a and closing the bypass line opening / closing valve 36b, and the bypass line flow state is realized by closing the main line opening / closing valve 36a and opening the bypass line opening / closing valve 36b.

[0102] The operation control unit M is configured to switch the line switching unit 36 ​​to the main line flow state as shown in FIG. 11 during the startup operation (early stage) from the start of startup operation until the temperature of the CO transformer Q rises to or above the set intermediate temperature (e.g., 140°C), and to the bypass line flow state with the cooling of the intercooler 34 stopped as shown in FIG. 12 during the startup operation (late stage) after the temperature of the CO transformer Q rises to or above the set intermediate temperature (e.g., 140°C).

[0103] When starting up, the operation control unit M controls the operation of the compressor D so that the outlet pressure of the compressor D becomes the target pressure (e.g., 0.8 MPa), and the internal pressure of the closed circuit C is maintained at a high pressure. In other words, the compressor D, for example, increases the pressure of the gas it receives to an intermediate pressure of the target pressure in the front-stage compression unit 33A, and then increases the pressure to the target pressure in the rear-stage compression unit 33B. In the bypass line flow state, the pressure of the heating gas received by compressor D is lower than in the main line flow state, so the compression amount of the heating gas in the front-stage compression section 33A and the rear-stage compression section 33B is greater in the bypass line flow state than in the main line flow state, and the temperature of the heating gas is higher in the bypass line flow state than in the main line flow state. Moreover, in the bypass line flow state, the intercooler 34 is switched to a state in which cooling is stopped, so the temperature of the heating gas becomes even higher.

[0104] (About the pure water flow state switching unit) As shown in Figures 10 and 12, during steady-state operation and startup operation (later stage), water (pure water) from a pure water tank 24 (an example of a water supply source) is supplied to the cooling pipe 11 as cooling water, and the water (pure water) after flowing through the cooling pipe 11 is supplied to the steam generating heat exchanger J as water for generating steam, and the generated steam is mixed with the gas (raw material gas, heating gas) flowing through the second flow path L2.

[0105] 11, in the start-up operation (early stage), water (pure water) from the pure water tank 24 (an example of a water supply source) is supplied to the steam generating heat exchanger J, and then returned to the pure water tank 24 via the steam cooling heat exchanger 27. In other words, the water vapor discharged from the steam discharge pipe section 7b of the steam generating heat exchanger J is liquefied in the steam cooling heat exchanger 27 and returned to the pure water tank 24.

[0106] Incidentally, the start-up operation (early stage) in this other embodiment may be carried out in a manner such that the heating steam U generated in the steam cooling heat exchanger 27 flows to the inlet portion of the cooling pipe 11 of the CO transformer Q, similar to the start-up operation (early stage) in the above embodiment.

[0107] [Other embodiments] (1) In the above embodiment and the other embodiment, an example is given of a form in which the hydrogen purging process, the water vapor discharge process, and the hydrogen filling process are performed sequentially when the hydrogen purification operation is stopped and the production of hydrogen gas is stopped for an extended period of time. However, in the water vapor discharge process, instead of the product gas (hydrogen gas), an inert gas (nitrogen gas, etc.) stored in an inert gas storage cylinder (e.g., a nitrogen cylinder, etc.) may be supplied to the closed circuit C, and in the hydrogen filling process, the inert gas (nitrogen gas, etc.) may be filled into the closed circuit C. That is, instead of the hydrogen filling process, an inert gas filling process may be performed in which an inert gas (such as nitrogen gas) is filled.

[0108] In this way, when filling the closed circulation circuit C with an inert gas (such as nitrogen gas), when starting up the system, first, an inert gas discharge process is performed in which the inert gas (such as nitrogen gas) filled in the closed circulation circuit C is discharged from the closed circulation circuit C while supplying the product gas (hydrogen gas) to the closed circulation circuit C, and then the start-up operation is performed.

[0109] (2) In the above embodiment and the other embodiment, the reformer H having a plurality of reforming reaction tubes A is exemplified, but the present invention can also be applied to a reformer H having a single reforming reaction tube A.

[0110] (3) In the above embodiment and the other embodiment, the reformer H is illustrated as being equipped with a heat exchanger J for generating steam and a heat exchanger N for preheating air. However, the heat exchanger J for generating steam and the heat exchanger N for preheating air may be formed in a location different from the reformer H.

[0111] (4) In the above embodiment and the other embodiment, a hydrogen separation section 20 is provided to separate hydrogen gas from the converted gas from the reforming section R. However, the converted gas may be used as it is, for example, by supplying the converted gas to a gas engine as product gas.

[0112] The configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradiction arises. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention. [Explanation of symbols]

[0113] 2 Reformer 2U Ceiling / Wall 2D bottom wall 2S side wall 2E Ejection section 2G outer wall 11 Cooling pipe 12. Metamorphic furnace body 12a Reformed gas inlet 12b Transformed gas outlet 13 Filler 24 Water sources 33A Pre-compression section 33B Rear compression section 34 Intercooler A Reforming reactor B. Reforming burner D Compressor G Raw material gas H reformer J Steam generation heat exchanger K Reformed gas Lm Main Line Lb bypass line Q CO transformer Z Carbon monoxide conversion catalyst

Claims

1. a reformer including a reforming reaction tube that steam-reforms the raw gas from the desulfurizer to produce a reformed gas and a reforming burner that heats the reforming reaction tube; a raw gas heating heat exchanger that heats the raw gas with the reformed gas from the reformer; a CO transformer that has a carbon monoxide shift catalyst that shifts carbon monoxide contained in the reformed gas from the raw gas heating heat exchanger to carbon dioxide to produce a shifted gas and that includes a cooling pipe through which cooling water that cools the carbon monoxide shift catalyst flows; a steam generating heat exchanger that heats steam-generating water with combustion gas from the reforming burner to produce steam to be mixed with the desulfurized raw gas; and a steam separation unit that separates steam from the shifted gas, When starting operation from a stopped state in which the supply of the raw material gas has been stopped and the combustion of the reforming burner has been stopped, the operation control unit stops the supply of the raw material gas to the compressor and burns the reforming burner, and circulates the temperature-raising gas through the compressor, the raw material gas heating heat exchanger, the desulfurizer, the reforming reaction tube, the raw material gas heating heat exchanger, the CO transformer, and the water vapor separation unit in a manner that the temperature-raising gas is returned to a location upstream of the compressor through a return path when it is discharged from the water vapor separation unit, thereby returning the temperature-raising gas to a location upstream of the compressor through a return path. a start-up operation for raising the temperature of the reforming reaction tube and the CO transformer to a set target state, followed by a steady operation for starting supply of the raw material gas to the compressor to generate the transformed gas; and, when the temperature of the CO transformer is raised to a set intermediate temperature or higher at which condensation of water vapor can be avoided during the start-up operation, a water vapor mixing process is performed in which water vapor generated in the water vapor generating heat exchanger is mixed with the temperature-raising gas that has passed through the desulfurizer, and the water vapor is separated from the temperature-raising gas in the water vapor separation unit.

2. 2. The reforming treatment device according to claim 1, wherein the operation control unit supplies water from a water supply source to the steam generating heat exchanger and supplies heating steam generated in the steam generating heat exchanger to the cooling pipe from the start of the startup operation until the temperature of the CO transformer rises to or above the set intermediate temperature.

3. the compressor includes an intercooler between a front compression section and a rear compression section, a main line and a bypass line having a greater passage resistance than the main line are provided in parallel in the return path, a line switching unit is provided that switches between a main line flow state in which the temperature-elevating gas flows through the main line and a bypass line flow state in which the temperature-elevating gas flows through the bypass line, 3. The reforming treatment device according to claim 1, wherein the operation control unit switches the line switching unit to the main line flow state from the start of the startup operation until the temperature of the CO transformer rises to or above the set intermediate temperature, and switches the line switching unit to the bypass line flow state with cooling of the intercooler stopped after the temperature of the CO transformer rises to or above the set intermediate temperature.

4. the reformer is configured to include a reformer furnace having a top wall, a bottom wall, and a cylindrical side wall disposed between the top wall and the bottom wall; the reforming burner is provided in a central portion of the ceiling wall in a state in which it burns downward, and the reforming reaction tubes are provided around the reforming burner in a position in which they hang down from the ceiling wall; an exhaust port for exhausting combustion gas from the reforming burner is opened at an upper side portion of the side wall, and a cylindrical outer wall is provided at an outer side portion of the side wall so as to be disposed between the ceiling wall and the bottom wall; the heat exchanger for generating steam is disposed in an external space between the side wall and the outer wall; The reforming treatment device according to any one of claims 1 to 3, wherein an external exhaust port is provided at a lower portion of the outer wall for exhausting combustion gas from the reforming burner that flows from the exhaust section through the external space.

5. the CO transformer is configured to include a cylindrical transformer body having a reformed gas inlet at one end and a transformed gas outlet after transformation treatment at the other end, 5. The reforming treatment device according to claim 1, wherein columnar packings are arranged in a radially central location inside the reforming furnace body, extending from the one end side to the other end side, and the cooling pipes are arranged spirally in a space outside the packings inside the reforming furnace body, and the carbon monoxide conversion catalyst is filled in the space.

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