JP2020079174A - Hydrogen production apparatus - Google Patents

Abstract

To provide a hydrogen production apparatus capable of suppressing deterioration of hydrogen production performance when reforming water is insufficient.SOLUTION: A hydrogen production apparatus 10A is provided with a carbon dioxide tank 50 and a carbon dioxide supply pipe P14 for supplying carbon dioxide gas to a preheating flow channel 24A. Carbon dioxide gas is stored in the carbon dioxide tank 50 and is supplied to the preheating flow channel 24A via the carbon dioxide supply pipe P14.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydrogen production device.

  2. Description of the Related Art Conventionally, as a hydrogen production device for obtaining hydrogen, there is known a device that reforms a raw material hydrocarbon into a reformed gas by a reforming device and then supplies the reformed gas to a PSA (Pressure Swing Adsorption) device (for example, patent Reference 1). In the hydrogen production device of Patent Document 1, reforming water is supplied to a reformer together with city gas, reformed gas containing hydrogen is generated by steam reforming, and the reformed gas is purified by a hydrogen purifier. , Manufactures high-purity product hydrogen.

JP, 2017-88490, A

  By the way, when the reformed gas is generated by steam reforming, if the reforming water is insufficient for some reason, the reforming efficiency is lowered, and accordingly, the hydrogen production performance is lowered. Therefore, it is conceivable to supply the reforming water from the outside of the device, but when tap water is used as the water source, it is necessary to provide a water treatment device. Further, in the case where the water treatment device is not provided, a large amount of pure water is required, and equipment such as a pure water producing device is required.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hydrogen production apparatus that suppresses a reduction in hydrogen production performance when reforming water is insufficient.

  A hydrogen production apparatus according to claim 1 is a raw material flow passage through which a hydrocarbon-based raw material and water flow, and a reformer containing hydrogen as a main component arranged downstream of the raw material flow passage to reform the raw material. A reformer having a reforming catalyst section provided with a reforming catalyst for generating gas; a carbon dioxide supply section for supplying carbon dioxide to the upstream side of the reforming catalyst section of the reformer; And a hydrogen purifier for purifying hydrogen by separating the reformed gas sent from the reformer into hydrogen gas and off-gas containing impurities.

  A hydrogen producing apparatus according to a first aspect includes a reformer having a raw material flow passage and a reforming catalyst section. A hydrocarbon-based raw material and water flow in the raw material flow passage, and the raw material is reformed in a reforming catalyst portion arranged downstream of the raw material flow passage to generate a reformed gas containing hydrogen as a main component. .. The reformed gas sent from the reformer is separated into off-gas containing impurities and hydrogen gas in the hydrogen purifier to purify hydrogen.

  Since the hydrogen production device according to claim 1 has the carbon dioxide supply part for supplying carbon dioxide to the upstream side of the reforming catalyst part of the reformer, the reforming water is insufficient due to some cause, and steam is generated. Even when reforming cannot be performed efficiently, carbon dioxide can be reformed by supplying carbon dioxide from the carbon dioxide supply unit. Therefore, by suppressing the deterioration of the reforming efficiency in the reformer, it is possible to suppress the deterioration of the hydrogen production performance.

  In the hydrogen producing apparatus according to claim 2, the reformer has a multi-cylinder shape in which a plurality of cylinders are coaxially arranged, and the raw material flow passage and the reforming catalyst section include the plurality of cylinders. Is formed between.

  By forming the reformer into a multi-cylindrical shape as in the hydrogen production apparatus according to the second aspect, the reformer can be made compact.

  In the hydrogen production device according to claim 3, the carbon dioxide supply unit supplies carbon dioxide to the upstream side of the raw material flow passage.

  By supplying carbon dioxide to the upstream side of the raw material flow passage as in the hydrogen production apparatus according to claim 3, the carbon dioxide and the raw material can be mixed and then supplied to the reforming catalyst section, which is a good improvement. Can contribute to quality reactions.

  In the hydrogen producing apparatus according to a fourth aspect, the reformer has a combustion unit that burns the off-gas sent from the hydrogen purifier to heat the reforming catalyst unit.

  In the hydrogen production apparatus according to the fourth aspect, the off-gas sent from the hydrogen purifier is supplied to the combustion section of the reformer and burned to heat the reforming catalyst section. Therefore, the reforming catalyst layer can be heated by effectively utilizing the off gas.

  In the hydrogen production apparatus according to a fifth aspect, the carbon dioxide supply unit supplies a part of the offgas to the upstream side of the reforming catalyst unit of the reformer.

  According to the hydrogen production apparatus of the fifth aspect, the carbon dioxide reforming reaction in the reforming catalyst layer can be promoted by using the carbon dioxide contained in the offgas. Further, the reforming reaction can be promoted again for the unreformed raw material gas contained in the off gas.

  The hydrogen production apparatus according to claim 6 is configured such that the carbon dioxide supply unit includes a carbon dioxide separation unit that is provided in an offgas passage that sends the offgas from the hydrogen purifier and that separates carbon dioxide from the offgas. There is.

  According to the hydrogen production device of the sixth aspect, carbon dioxide contained in the offgas can be separated and used to accelerate the carbon dioxide reforming reaction in the reforming catalyst layer.

  The hydrogen production apparatus according to claim 7, wherein the reformer has a combustor that combusts the off-gas sent from the hydrogen purifier and heats the reforming catalyst, and the carbon dioxide separation unit includes the combustor. The branched off gas after the carbon dioxide is separated from the off gas is supplied to the combustion section.

  According to the hydrogen production apparatus of claim 7, since the branch off gas after removing carbon dioxide is supplied to the combustion section, the amount of carbon dioxide supplied to the combustion section is reduced and the proportion of combustible gas is increased. Can be made

  In the hydrogen production apparatus according to claim 8, the reformer has a combustor that combusts the off-gas sent from the hydrogen purifier to heat the reforming catalyst part, and the carbon dioxide separation part includes the combustor. The branched off gas after carbon dioxide is separated from the off gas is supplied to the hydrogen purifier.

  According to the hydrogen production apparatus of claim 8, since the branched offgas after removing carbon dioxide is supplied to the hydrogen purifier, hydrogen in the branched offgas can be refined again to be a product. Efficiency is improved.

  ADVANTAGE OF THE INVENTION According to this invention, when reforming water is insufficient, carbon dioxide reforming can suppress the fall of hydrogen production performance.

It is a schematic block diagram which showed the hydrogen production apparatus which concerns on 1st Embodiment. It is a sectional view showing a multi-cylinder type reformer of a hydrogen production device concerning a 1st embodiment. It is a schematic block diagram which showed the hydrogen production apparatus which concerns on 2nd Embodiment. It is a schematic block diagram which showed the hydrogen production apparatus which concerns on 3rd Embodiment. It is a schematic block diagram which showed the hydrogen production apparatus which concerns on 4th Embodiment.

<First Embodiment>
An example of the hydrogen production device according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the hydrogen production apparatus 10A according to the present embodiment includes a multi-cylinder reformer 12, a compressor 14, a hydrogen purifier 16, and an offgas tank 18. Further, it is provided with a pre-pressurization water separation unit 30, a post-pressurization water separation unit 32, and a combustion exhaust gas water separation unit 34. The hydrogen producing apparatus 10A produces hydrogen from a hydrocarbon raw material, and in the present embodiment, a case where city gas containing methane as a main component is used as an example of the hydrocarbon raw material will be described. Note that FIG. 1 schematically shows the configuration of the hydrogen production apparatus 10A, and the hydrogen production apparatus 10A may include other configurations.

(Reformer)
As shown in FIG. 2, the multi-cylinder reformer 12 has a plurality of cylindrical walls 20A, 20B, 20C, 20D that are arranged in multiple layers. The plurality of cylindrical walls 20A, 20B, 20C, 20D are formed in, for example, a cylindrical shape or an elliptic cylindrical shape. A combustion section 21 which is a combustion space is formed inside the first cylindrical wall 20A from the inside among the plurality of cylindrical walls 20A, 20B, 20C, 20D. A combustion exhaust gas passage 23 is formed between the first tubular wall 20A and the second tubular wall 20B. A first flow path 24 is formed between the second tubular wall 20B and the third tubular wall 20C. Further, a second flow path 25 is formed between the third cylindrical wall 20C and the fourth cylindrical wall 20D. The multi-cylinder reformer 12 is an example of a reformer, and reformers of other forms may be used.

  The upper part of the first flow path 24 is formed as a preheating flow path 24A, and the preheating flow path 24A is provided with a spiral member 24B. The preheating channel 24A is formed in a spiral shape by the spiral member 24B. A raw material supply pipe P1 for supplying city gas as a raw material and a reforming water supply pipe P9 for supplying reforming water are connected to the upper end of the preheating channel 24A. City gas is supplied from the raw material supply pipe P1 and reformed water is supplied from the reforming water supply pipe P9 to the preheating channel 24A. The city gas and the reformed water flow from the upper side to the lower side in the preheating flow path 24A, and are heat-exchanged with the combustion exhaust gas via the second cylindrical wall 20B to vaporize the water. In the preheating channel 24A, the mixed gas is generated by mixing the city gas and the vapor-phase reforming water (steam).

  In this embodiment, city gas is used as a raw material, but it is not particularly limited as long as it is a gas capable of steam reforming, and hydrocarbon fuel can be used. Examples of the hydrocarbon fuel include natural gas, LP gas (liquefied petroleum gas), coal reformed gas, and lower hydrocarbon gas.

  A carbon dioxide supply pipe P14 is connected to the raw material supply pipe P1. The carbon dioxide supply pipe P14 is connected to the carbon dioxide tank 50 and supplies carbon dioxide gas to the preheating channel 24A. Carbon dioxide gas is stored in the carbon dioxide tank 50, and the carbon dioxide gas is supplied to the preheating channel 24A via the carbon dioxide supply pipe P14. The carbon dioxide tank 50 delivers carbon dioxide gas when the supply of reforming water required for steam reforming is insufficient. The delivered carbon dioxide gas is mixed with the city gas and the reforming water and flows through the preheating channel 24A.

  A reforming catalyst layer 24C is provided below the preheating channel 24A in the first channel 24. The reforming catalyst layer 24C is provided with a catalyst for steam reforming/carbon dioxide reforming city gas to generate reformed gas containing hydrogen as a main component. The mixed gas (city gas and steam, or city gas, steam, and carbon dioxide gas) generated in the preheating channel 24A is supplied to the reforming catalyst layer 24C. In the reforming catalyst layer 24C, the mixed gas is heated by the combustion exhaust gas flowing through the combustion exhaust gas flow path 23, and the reforming gas containing hydrogen as a main component is generated by the steam reforming reaction and the carbon dioxide reforming reaction.

  The second flow passage 25 is arranged radially outside the first flow passage 24, and the lower end portion of the second flow passage 25 communicates with the lower end portion of the first flow passage 24. In the second flow passage 25, a CO shift catalyst layer 26 and a CO selective oxidation catalyst layer 27 are formed at positions corresponding to the preheating flow passage 24A. In the CO conversion catalyst layer 26, carbon monoxide contained in the reformed gas reacts with steam to be converted into hydrogen and carbon dioxide, and carbon monoxide is reduced.

  The CO selective oxidation catalyst layer 27 is arranged on the downstream side of the CO shift catalyst layer 26. An oxidant gas supply pipe P2B that supplies an oxidant gas is connected between the CO conversion catalyst layer 26 and the CO selective oxidation catalyst layer 27. In the CO selective oxidation catalyst layer 27, carbon monoxide reacts with oxygen to be converted into carbon dioxide, and carbon monoxide is removed. A reformed gas discharge pipe P3 is connected to the upper end of the second flow path 25 on the downstream side of the CO selective oxidation catalyst layer 27. The reformed gas is discharged from the reformed gas discharge pipe P3 after the carbon monoxide is removed by the CO selective oxidation catalyst layer 27.

  Although the CO selective oxidation catalyst layer 27 is provided in the present embodiment, the CO selective oxidation catalyst layer 27 is not essential, and the CO selective oxidation catalyst layer 27 may be omitted. In this case, the oxidizing gas supply pipe P2B is also unnecessary.

  A burner 22 is arranged downward on the upper portion of the combustion section 21. An off-gas pipe P7 is connected to the burner 22, and off-gas described below is supplied as fuel from the off-gas pipe P7. Further, an air supply pipe P2 for supplying combustion air is connected to the upper end of the combustion section 21. A raw material branch pipe P1A branched from the raw material supply pipe P1 is further connected to the burner 22. An air branch pipe P2A branched from the air supply pipe P2 is connected to the raw material branch pipe P1A. A gas in which city gas is mixed with air is supplied to the burner 22 separately from the off gas. Either or both of the off gas for combustion and the city gas are supplied as needed.

  The combustion exhaust gas passage 23 is formed radially outside of the combustion section 21, and the lower end of the combustion exhaust gas passage 23 is in communication with the combustion section 21. A gas discharge pipe P10 for discharging gas is connected to the upper end of the combustion exhaust gas flow path 23. The gas discharge pipe P10 is connected to the upper end surface of the multi-cylinder reformer 12. The combustion exhaust gas discharged from the combustion section 21 flows through the combustion exhaust gas flow path 23 from the lower side to the upper side, and is discharged to the outside of the multi-cylinder reformer 12 through the gas discharge pipe P10.

  The reformed gas sent from the multi-cylinder reformer 12 to the reformed gas discharge pipe P3 is, as shown in FIG. 1, a pre-pressurization water separation unit 30, a compressor 14, a post-pressurization water separation unit 32, and It flows through the hydrogen purifier 16 in this order. That is, in the gas flow direction, from the upstream side to the downstream side, the multi-tubular reformer 12, the pre-pressurization water separation unit 30, the compressor 14, the post-pressurization water separation unit 32, and the hydrogen purifier 16 are arranged in this order. It is arranged.

(Separation part before boosting)
The pre-pressurization water separation unit 30 has an upper part as a gas chamber 30A and a lower part as a liquid chamber 30B. The downstream end of the reformed gas discharge pipe P3 is connected to the gas chamber 30A. Further, the upstream end of the communication flow path pipe P4 is connected to the gas chamber 30A. A water delivery port 30C is formed at the bottom of the liquid chamber 30B, and a reformed gas water pipe P8A is connected to the water delivery port 30C. The steam in the reformed gas is condensed by being cooled in the heat exchanger HE1 arranged upstream of the pre-pressurization water separation unit 30. Water separated from the reformed gas by condensation is stored in the liquid chamber 30B and sent to the reformed gas water pipe P8A.

(Compressor)
A connecting passage pipe P4 through which the reformed gas from the pre-pressurization water separation unit 30 flows and a connecting passage pipe P5 through which the reformed gas supplied to the post-pressurization water separation unit 32 flows are connected to the compressor 14. ing. The compressor 14 compresses and boosts the pressure of the reformed gas supplied from the pre-pressurization water separation unit 30 and supplies the reformed gas to the post-pressurization water separation unit 32.

(Separator after boosting)
The post-pressurization water separation part 32 has an upper part as a gas chamber 32A and a lower part as a liquid chamber 32B. The downstream end of the communication flow path pipe P5 is connected to the gas chamber 32A. Further, the upstream end of the communication flow path pipe P6 is connected to the gas chamber 32A. A water delivery port 32C is formed at the bottom of the liquid chamber 32B, and a reformed gas water pipe P8B is connected to the water delivery port 32C. The steam in the reformed gas is condensed by being cooled in the heat exchanger HE2 arranged upstream of the water separation unit 32 after pressurization. The water separated from the reformed gas by condensation is stored in the liquid chamber 32B and sent to the reformed gas water pipe P8B.

  A buffer tank 36 is provided downstream of the post-pressurization water separation unit 32 and upstream of the hydrogen purifier 16. The buffer tank 36 stores the reformed gas supplied from the water separator 32 after pressurization. The reformed gas once accumulated in the buffer tank 36 is sent to the hydrogen purifier 16.

(Hydrogen refiner)
To the hydrogen purifier 16, the downstream end of the communication flow path pipe P6 through which the reformed gas from the post-pressurization water separation unit 32 flows is connected. As the hydrogen purifier 16, for example, a PSA device is used. Hydrogen is purified by separating the reformed gas into impurities and hydrogen by the hydrogen purifier 16. A hydrogen supply pipe P11 is connected to the hydrogen purifier 16, and the purified hydrogen is sent to the hydrogen supply pipe P11 and stored in a tank (not shown) or sent to a hydrogen supply line.

  The upstream end of the offgas pipe P7 is connected to the hydrogen purifier 16. The downstream end of the offgas pipe P7 is connected to the burner 22 of the multi-cylinder reformer 12. The off gas separated by the hydrogen purification is sent from the hydrogen purifier 16 to the off gas pipe P7. An offgas tank 18 is provided in the offgas pipe P7. The off gas is temporarily stored in the off gas tank 18, flows through the off gas pipe P7, and is supplied as fuel to the burner 22 (see FIG. 2) of the multi-cylinder reformer 12.

(Combustion exhaust gas water separation unit)
The combustion exhaust gas water separation part 34 has an upper part as a gas chamber 34A and a lower part as a liquid chamber 34B. The downstream end of the gas exhaust pipe P10 is connected to the gas chamber 34A. An external discharge pipe P12 is connected to the gas chamber 34A. A water outlet 34C is formed at the bottom of the liquid chamber 34B, and a combustion exhaust gas water pipe P8C is connected to the water outlet 34C. The combustion exhaust gas water separation unit 34 has a larger capacity than the pre-pressurization water separation unit 30 and the post-pressurization water separation unit 32.

  Further, the combustion exhaust gas water separation unit 34 is arranged vertically above the pre-pressurization water separation unit 30 and the post-pressurization water separation unit 32. Here, "the combustion exhaust gas water separation unit 34 is arranged vertically above the pre-pressurization water separation unit 30 and the post-pressurization water separation unit 32" means that the bottom of the liquid chamber 34B is the bottom of the liquid chamber 30B. , And that is arranged vertically above the bottom of the liquid chamber 32B. The bottom of the liquid chamber 34B is preferably arranged vertically above the upper ends of the pre-pressurization water separation part 30 and the post-pressurization water separation part 32.

  Furthermore, the inner diameter of the combustion exhaust gas water pipe P8C is set larger than the inner diameters of the reformed gas water pipes P8A and P8B.

  The combustion exhaust gas is sent from the combustion section 21 through the combustion exhaust gas flow path 23 to the gas exhaust pipe P10. The water vapor in the combustion exhaust gas is condensed by being cooled in the heat exchanger HE3 arranged upstream of the combustion exhaust gas water separation unit 34. The water separated from the combustion exhaust gas by condensation is stored in the liquid chamber 34B and sent to the combustion exhaust gas water pipe P8C. The combustion exhaust gas after the water is separated is discharged to the outside through the external discharge pipe P12.

  A water tank 40 is arranged at the bottom of the hydrogen production device 10A. A water inlet 40A is formed on the top surface of the water tank 40, and the reformed gas water pipes P8A and P8B and the combustion exhaust gas water pipe P8C are connected to the water inlet 40A after joining. The pipe after the joining is referred to as a water inflow pipe P8. The inner diameter of the water inflow pipe P8 is larger than the inner diameter of the combustion exhaust gas water pipe P8C.

  The water tank 40 has a larger capacity than the total amount of water that can be stored in the pre-pressurization water separation unit 30, the post-pressurization water separation unit 32, and the combustion exhaust gas water separation unit 34. It is arranged vertically below the post-water separation unit 32 and the combustion exhaust gas water separation unit 34. Here, "the water tank 40 is arranged vertically below the pre-pressurization water separation part 30, the post-pressurization water separation part 32, and the combustion exhaust gas water separation part 34" means the bottom part of the liquid chamber 30B. It means that the bottom of the liquid chamber 32B and the bottom of the liquid chamber 34B are arranged vertically above the water inlet 40A of the water tank 40.

  An upstream end of the reforming water supply pipe P9 is connected to the water tank 40. The reforming water supply pipe P9 is provided with a water treatment device (ion exchange resin) 42 for removing dissolved ionic components. Further, the reforming water supply pipe P9 is provided with a pump 44, and by driving the pump 44, the water stored in the water tank 40 is supplied to the multi-cylinder reformer 12 via the water treatment device 42. It A pure water supply pipe P13 is connected to the reforming water supply pipe P9 downstream of the water treatment device 42 and upstream of the pump 44. Pure water is supplied from the pure water supply pipe P13 to the multi-cylinder reformer 12 via the reforming water supply pipe P9 as necessary.

(Action)
Next, the operation of the hydrogen production device 10A will be described.

  In normal operation, city gas and reforming water are supplied from the raw material supply pipe P1 and the reforming water supply pipe P9 to the multi-cylinder reformer 12, and the city gas and the reforming water are mixed in the preheating passage 24A. While being heated, the mixed gas becomes a mixed gas and is supplied to the reforming catalyst layer 24C. In the reforming catalyst layer 24C, the mixed gas is steam-reformed by receiving heat from the combustion exhaust gas flowing through the combustion exhaust gas passage 23, and a reformed gas containing hydrogen as a main component is generated. The reformed gas is supplied to the CO shift catalyst layer 26 through the reformed gas passage 25. In the CO conversion catalyst layer 26, carbon monoxide contained in the reformed gas reacts with steam to be converted into hydrogen and carbon dioxide, and carbon monoxide is reduced. The reformed gas that has passed through the CO conversion catalyst layer 26 is supplied to the CO selective oxidation catalyst layer 27 together with the oxidizing gas (air) supplied from the oxidant gas supply pipe P2B, and carbon monoxide reacts with oxygen on the catalyst. Are converted to carbon dioxide and carbon monoxide is removed. The reformed gas in which carbon monoxide is reduced in the CO selective oxidation catalyst layer 27 is sent to the reformed gas discharge pipe P3.

  The reformed gas is supplied to the gas chamber 30A of the pre-pressurization water separation unit 30 via the heat exchanger H1 provided in the reformed gas discharge pipe P3. The water contained in the reformed gas supplied to the gas chamber 30A is condensed by being cooled by the heat exchanger H1, is stored in the liquid chamber 30B, and is delivered to the water tank 40 via the reformed gas water pipe P8A. The reformed gas, from which water has been separated, flows from the gas chamber 30A through the communication flow path pipe P4, is supplied to the compressor 14, and is compressed by the compressor 14.

  The compressed reformed gas flows through the communication flow path pipe P6 and is supplied to the gas chamber 32A of the post-pressurization water separation section 32 via the heat exchanger H2. The water vapor contained in the reformed gas supplied to the gas chamber 32A is condensed by being cooled by the heat exchanger H2, is stored in the liquid chamber 32B, and is delivered to the water tank 40 via the reformed gas water pipe P8B. From the gas chamber 32A, the reformed gas from which water has been separated flows through the communication flow path pipe P6 and is supplied to the hydrogen purifier 16.

  In the hydrogen purifier 16, the reformed gas is separated into impurities and hydrogen, and the hydrogen is sent to the hydrogen supply pipe P11. The delivered hydrogen is stored in a tank (not shown) or sent to a hydrogen supply line. On the other hand, the off gas containing impurities other than hydrogen separated from the reformed gas flows through the off gas pipe P7 and is supplied as fuel to the burner 22 of the multi-cylinder reformer 12.

  In the combustion section 21 of the multi-cylinder reformer 12, the off gas is combusted, and the combustion exhaust gas is supplied to the gas chamber 34A of the combustion exhaust gas water separation section 34 via the gas discharge pipe P10. The water vapor contained in the combustion exhaust gas supplied to the gas chamber 34A is condensed by being cooled by the heat exchanger H3, is stored in the liquid chamber 34B, and is delivered to the water tank 40 via the combustion exhaust gas water pipe P8C. The combustion exhaust gas from which the water has been separated is discharged to the outside through the external discharge pipe P12.

  When the reforming water supplied to the multi-cylinder reformer 12 is insufficient due to some cause such as water interruption or failure, the carbon dioxide supply operation is performed as compared with the normal operation. In the carbon dioxide supply operation, carbon dioxide gas is sent from the carbon dioxide tank 50 to the carbon dioxide supply pipe P14. As a result, carbon dioxide gas is supplied to the preheating channel 24A via the carbon dioxide supply pipe P14. Carbon dioxide gas, city gas, and reforming water are mixed in the preheating channel 24A and supplied to the reforming catalyst layer 24C. In the reforming catalyst layer 24C, the above-mentioned mixed gas is subjected to steam reforming and carbon dioxide reforming by receiving heat from the combustion exhaust gas flowing through the combustion exhaust gas flow path 23 to generate reformed gas containing hydrogen as a main component. To be done. The reformed gas flows through the reformed gas flow path 25 in the order of the CO shift catalyst layer 26 and the CO selective oxidation catalyst layer 27, and is delivered to the reformed gas discharge pipe P3, as in the normal state.

  10 A of hydrogen production apparatuses of this embodiment have the carbon dioxide tank 50 for supplying a carbon dioxide gas to the upstream of the reforming catalyst layer 24C, and the carbon dioxide supply pipe P14. Therefore, even when the reforming water is insufficient and the steam reforming is not efficiently performed, the carbon dioxide reforming can be performed by supplying the carbon dioxide gas. Therefore, the deterioration of the reforming efficiency in the multi-cylinder reformer 12 can be suppressed, and the deterioration of the hydrogen production performance can be suppressed.

  Further, in the present embodiment, since the water collected in the water tank 40 is returned to the multi-cylinder reformer 12 as reforming water, the water discharged from the multi-cylinder reformer 12 is effectively used, The amount of water newly supplied from the outside can be reduced.

  In addition, in this embodiment, although the hydrogen production apparatus including the compressor 14 has been described, the present invention may be applied to a hydrogen production apparatus that does not include the compressor 14, or the compressor may be a multi-cylinder type. You may apply to the hydrogen production apparatus arrange|positioned rather than the quality machine 12 at the upstream side.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

  In the hydrogen production device 10B of the present embodiment, as shown in FIG. 3, the carbon dioxide supply pipe P14 branched from the offgas pipe P7 is connected to the raw material supply pipe P1. The carbon dioxide tank 50 may be provided, but in the present embodiment, an example in which the carbon dioxide tank 50 is not provided will be described. In this embodiment, the configuration other than the carbon dioxide tank 50 and the carbon dioxide supply pipe P14 is the same as that of the first embodiment.

  The upstream end of the carbon dioxide supply pipe P14 is connected to the offgas pipe P7 downstream of the offgas tank 18. The downstream end of the carbon dioxide supply pipe P14 is connected to the raw material supply pipe P1. A flow rate adjusting valve 52 is provided in the carbon dioxide supply pipe P14. The flow rate adjusting valve 52 adjusts the partial flow rate from the off gas pipe P7 to the carbon dioxide supply pipe P14.

(Action)
Next, the operation of the hydrogen production device 10B will be described.

  In normal operation, the off-gas supply to the carbon dioxide supply pipe P14 is stopped by the flow rate adjusting valve 52, and hydrogen production is performed as in the first embodiment.

  When the reforming water supplied to the multi-cylinder reformer 12 is insufficient due to some cause such as water outage or failure in comparison with the normal operation, the carbon dioxide supply operation is performed. In the carbon dioxide supply operation, the flow rate adjusting valve 52 is opened and the off gas containing the carbon dioxide gas for carbon dioxide reforming required in the reforming catalyst layer 24C is diverted to the carbon dioxide supply pipe P14. As a result, the off gas containing carbon dioxide gas is supplied to the preheating channel 24A via the carbon dioxide supply pipe P14. Carbon dioxide gas, city gas, and reforming water are mixed in the preheating channel 24A and supplied to the reforming catalyst layer 24C. In the reforming catalyst layer 24C, the above-mentioned mixed gas is subjected to steam reforming and carbon dioxide reforming by receiving heat from the combustion exhaust gas flowing through the combustion exhaust gas flow path 23 to generate reformed gas containing hydrogen as a main component. To be done.

  In the reforming catalyst layer 24C, unreformed methane contained in the offgas is reformed. The reformed gas also includes hydrogen gas contained in the off gas. The reformed gas flows through the reformed gas flow path 25 in the order of the CO shift catalyst layer 26 and the CO selective oxidation catalyst layer 27, and is delivered to the reformed gas discharge pipe P3, as in the normal state.

  The hydrogen production device 10B of the present embodiment also has a carbon dioxide supply pipe P14 for supplying carbon dioxide gas to the upstream side of the reforming catalyst layer 24C. Therefore, even when the reforming water is insufficient and the steam reforming is not efficiently performed, the carbon dioxide reforming can be performed by supplying the carbon dioxide gas. Therefore, the deterioration of the reforming efficiency in the multi-cylinder reformer 12 can be suppressed, and the deterioration of the hydrogen production performance can be suppressed.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. The same parts as those in the first and second embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

  In the hydrogen production device 10C of the present embodiment, as shown in FIG. 4, a carbon dioxide separation device 54 is provided in a carbon dioxide supply pipe P14 branched from an offgas pipe P7. In the present embodiment, the configuration other than the carbon dioxide separator 54 is the same as in the second embodiment.

  A carbon dioxide separator 54 is connected to the carbon dioxide supply pipe P14 separated from the off-gas pipe P7, downstream of the flow rate adjusting valve 52. The carbon dioxide separator 54 separates the carbon dioxide gas from the off gas. As the carbon dioxide separation device 54, a carbon dioxide separation membrane or the like can be used. The separated carbon dioxide gas is sent to the carbon dioxide supply pipe P14. The off-gas (branch off-gas) after the carbon dioxide gas is separated is joined with the off-gas pipe P7 from the carbon dioxide separator 54 through the joining pipe P15.

(Action)
Next, the operation of the hydrogen production device 10C will be described.

  In normal operation, the off-gas supply to the carbon dioxide supply pipe P14 is stopped by the flow rate adjusting valve 52, and hydrogen production is performed as in the first embodiment.

  When the reforming water supplied to the multi-cylinder reformer 12 is insufficient due to some cause such as water interruption or failure, the carbon dioxide supply operation is performed as compared with the normal operation. In the carbon dioxide supply operation, the flow rate adjusting valve 52 is opened and the off gas containing the carbon dioxide gas for carbon dioxide reforming required in the reforming catalyst layer 24C is diverted to the carbon dioxide supply pipe P14. The off-gas is separated from the carbon dioxide gas by the carbon dioxide separator 54, and the separated carbon dioxide gas is sent to the carbon dioxide supply pipe P14. As a result, carbon dioxide gas is supplied to the preheating channel 24A. Carbon dioxide gas, city gas, and reforming water are mixed in the preheating channel 24A and supplied to the reforming catalyst layer 24C. In the reforming catalyst layer 24C, the above-mentioned mixed gas is subjected to steam reforming and carbon dioxide reforming by receiving heat from the combustion exhaust gas flowing through the combustion exhaust gas flow path 23 to generate reformed gas containing hydrogen as a main component. To be done.

  On the other hand, the branched off gas after the carbon dioxide gas is separated by the carbon dioxide separator 54 merges with the off gas pipe P7 through the merge pipe P15 and is supplied to the burner 22.

  The hydrogen production device 10C of the present embodiment also has a carbon dioxide supply pipe P14 for supplying carbon dioxide gas to the upstream side of the reforming catalyst layer 24C. Therefore, even when the reforming water is insufficient and the steam reforming is not efficiently performed, the carbon dioxide reforming can be performed by supplying the carbon dioxide gas. Therefore, the deterioration of the reforming efficiency in the multi-cylinder reformer 12 can be suppressed, and the deterioration of the hydrogen production performance can be suppressed.

  Further, since the amount of carbon dioxide gas supplied to the burner 22 is reduced, the ratio of combustible gas is increased and efficient combustion can be achieved.

<Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described. The same parts as those in the first to third embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 5, in the hydrogen production device 10D of the present embodiment, the carbon dioxide separation device 54 is provided in the carbon dioxide supply pipe P14 branched from the offgas pipe P7, as in the third embodiment. . In the present embodiment, the configuration other than the branch off-gas supply destination after the carbon dioxide gas is separated by the carbon dioxide separator 54 is the same as that of the third embodiment.

  The upstream end of the regeneration branch offgas pipe P16 is connected to the carbon dioxide separator 54, and the downstream end of the regeneration branch offgas pipe P16 is connected to the communication flow passage pipe P4. The branch off-gas after the carbon dioxide gas is separated by the carbon dioxide separator 54 is sent to the regeneration branch off-gas pipe P16 and merges with the reformed gas in the communication flow pipe P4.

(Action)
Next, the operation of the hydrogen production device 10D will be described.

  In normal operation, the off-gas supply to the carbon dioxide supply pipe P14 is stopped by the flow rate adjusting valve 52, and hydrogen production is performed as in the first embodiment.

  When the reforming water supplied to the multi-cylinder reformer 12 is insufficient due to some cause such as water interruption or failure, the carbon dioxide supply operation is performed as compared with the normal operation. In the carbon dioxide supply operation, the flow rate adjusting valve 52 is opened and the off gas containing the carbon dioxide gas for carbon dioxide reforming required in the reforming catalyst layer 24C is diverted to the carbon dioxide supply pipe P14. The off-gas is separated from the carbon dioxide gas by the carbon dioxide separator 54, and the separated carbon dioxide gas is sent to the carbon dioxide supply pipe P14. As a result, carbon dioxide gas is supplied to the preheating channel 24A. Carbon dioxide gas, city gas, and reforming water are mixed in the preheating channel 24A and supplied to the reforming catalyst layer 24C. In the reforming catalyst layer 24C, the above-mentioned mixed gas is subjected to steam reforming and carbon dioxide reforming by receiving heat from the combustion exhaust gas flowing through the combustion exhaust gas passage 23 to generate reformed gas containing hydrogen as a main component. To be done.

  On the other hand, the branch off gas after the carbon dioxide gas is separated by the carbon dioxide separator 54 is sent to the connection flow path pipe P4 through the regeneration branch off gas pipe P16, merges with the reformed gas, and is supplied to the compressor 14. And is supplied to the hydrogen purifier 16 via the same route as in the normal state. In the hydrogen purifier 16, the reformed gas containing the branched off gas is separated into impurities and hydrogen, and the hydrogen is sent to the hydrogen supply pipe P11. The off gas containing impurities other than hydrogen separated from the reformed gas is sent to the off gas pipe P7.

  The hydrogen generator 10D of the present embodiment also has a carbon dioxide supply pipe P14 for supplying carbon dioxide gas to the upstream side of the reforming catalyst layer 24C. Therefore, even when the reforming water is insufficient and the steam reforming is not efficiently performed, the carbon dioxide reforming can be performed by supplying the carbon dioxide gas. Therefore, the deterioration of the reforming efficiency in the multi-cylinder reformer 12 can be suppressed, and the deterioration of the hydrogen production performance can be suppressed.

  Further, since the branched off-gas is re-refined by the hydrogen purifier 16 to produce product hydrogen, the amount of carbon dioxide gas supplied to the burner 22 decreases, so that the proportion of combustible gas increases and the hydrogen production efficiency increases. Can be improved.

10A, 10B, 10C Hydrogen production device 12 Multiple cylinder reformer (reformer)
16 Hydrogen Purifier 21 Combustion Section 24A Preheating Flow Path (Raw Material Flow Path)
24C reforming catalyst layer (reforming catalyst section)
50 Carbon dioxide tank (carbon dioxide supply unit)
54 Carbon dioxide separator (carbon dioxide separator)
P7 off-gas pipe (off-gas passage)
P14 Carbon dioxide supply pipe (carbon dioxide supply unit)

Claims (8)

A raw material flow passage through which a hydrocarbon-based raw material and water flow, and a reforming catalyst arranged downstream of the raw material flow passage to reform the raw material to generate a reformed gas containing hydrogen as a main component are provided. A reformer having a reforming catalyst section,
A carbon dioxide supply unit for supplying carbon dioxide to the upstream side of the reforming catalyst unit of the reformer,
A hydrogen purifier that separates the reformed gas delivered from the reformer into hydrogen gas and off-gas containing impurities, and purifies hydrogen;
Hydrogen generator equipped with.   The reformer has a multi-cylinder shape in which a plurality of cylinders are coaxially arranged, and the raw material flow passage and the reforming catalyst section are formed between the plurality of cylinders. 1. The hydrogen production device according to 1.   The hydrogen production device according to claim 1 or 2, wherein the carbon dioxide supply unit supplies carbon dioxide to an upstream side of the raw material flow passage. The reformer has a combustor that combusts the off-gas sent from the hydrogen purifier to heat the reforming catalyst.
The hydrogen production device according to claim 1.   The hydrogen production device according to claim 1, wherein the carbon dioxide supply unit supplies a part of the off-gas to the upstream side of the reforming catalyst unit of the reformer.   The carbon dioxide supply unit is configured to include a carbon dioxide separation unit that is provided in an offgas passage that sends the offgas from the hydrogen purifier and that separates carbon dioxide from the offgas. The hydrogen production apparatus according to item 1. The reformer has a combustion unit that burns the off-gas sent from the hydrogen purifier to heat the reforming catalyst unit,
The hydrogen production apparatus according to claim 6, wherein the branched off gas after carbon dioxide is separated from the off gas in the carbon dioxide separation unit is supplied to the combustion unit. The reformer has a combustion unit that combusts the off-gas sent from the hydrogen purifier to heat the reforming catalyst unit,
The hydrogen production device according to claim 6, wherein the branched off gas after carbon dioxide is separated from the off gas in the carbon dioxide separation unit is supplied to the hydrogen purifier.