JP2020079173A - Hydrogen production apparatus - Google Patents

Abstract

To provide a hydrogen production apparatus having improved hydrogen production efficiency.SOLUTION: A hydrogen production apparatus 10A has a hydrogen purifier 16 that separates a reformed gas into a hydrogen gas and an off-gas comprising an impurity. The off-gas comprising an impurity is sent to an off-gas path P7 and merged into the reformed gas, and supplied again to the hydrogen purifier 16 for re-purification.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 highly pure hydrogen.

JP, 2017-88490, A

  By the way, in Patent Document 1, the off-gas containing impurities discharged when the reformed gas is purified by the hydrogen purifier is supplied to the burner of the reformer and used as fuel. At present, the off-gas contains hydrogen gas, and if the amount of this hydrogen gas is large, the ratio of product hydrogen water that can be produced to the raw material will be low, and the hydrogen production efficiency will be reduced.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a hydrogen production apparatus that improves hydrogen production efficiency.

  A hydrogen production apparatus according to claim 1 separates a reformer that reforms a raw material to generate a reformed gas containing hydrogen as a main component, and the reformed gas into a hydrogen gas and an off-gas containing impurities, A hydrogen purifier that delivers the off-gas to the off-gas passage and also delivers the hydrogen gas to the hydrogen gas passage, and a re-refining that directly or indirectly supplies the off-gas delivered to the off-gas passage to the hydrogen purifier. And an off gas supply unit.

  A hydrogen producing apparatus according to claim 1 includes a reformer and a hydrogen purifier. The off-gas containing impurities separated by the hydrogen purifier and sent to the off-gas passage is supplied to the hydrogen purifier by the re-refining off-gas supply unit. The off gas supply to the hydrogen purifier by the re-refining off gas supply unit may be a direct supply or an indirect supply after being processed by passing through another device or the like. In the hydrogen purifier, by separating off gas into hydrogen gas and off gas containing impurities, product hydrogen can be obtained from the off gas. Thereby, the hydrogen production efficiency can be improved.

  The hydrogen producing apparatus according to claim 2, wherein the reformer includes a combustion unit that combusts a combustible gas, and a combustion gas supply unit that supplies the offgas sent to the offgas passage to the combustion unit. .

  According to the hydrogen production apparatus of the second aspect, the off gas can be used as the heat source of the reformer by supplying the off gas to the combustion section of the reformer.

  In the hydrogen production apparatus according to claim 3, the re-refining off-gas supply unit merges the off-gas with the raw material.

  In the hydrogen production device according to the third aspect, the off gas is combined with the raw material. The off-gas and the raw material may be merged on the merged side of the reformer or in the reformer. By thus joining the offgas with the raw material, the unreformed raw material gas contained in the offgas can be reformed by the reformer.

  In the hydrogen production apparatus according to claim 4, a compressor for boosting the pressure of the reformed gas is provided in a flow path between the reformer and the hydrogen purifier, and the re-refining off-gas supply unit includes: The off gas is combined with the reformed gas on the upstream side of the compressor and the downstream side of the reformer.

  In the hydrogen production device according to the fourth aspect, since the off gas joins with the reformed gas on the upstream side of the compressor, it is possible to apply a pressure increase suitable for the refining process in the hydrogen purifier to the off gas.

  In the hydrogen production apparatus according to claim 5, the re-purification off-gas supply unit includes a carbon dioxide separation unit that separates carbon dioxide gas from the off-gas, and the carbon dioxide separation unit separates carbon dioxide. After the subsequent carbon dioxide separation, the off gas is supplied to the hydrogen purifier.

  In the hydrogen production device according to the fifth aspect, carbon dioxide is separated from the off gas by the carbon dioxide separation unit, and the off gas is supplied to the hydrogen purifier after the carbon dioxide separation. Since off-gas after carbon dioxide separation has a higher hydrogen concentration than off-gas, it is possible to efficiently perform the refining process in the hydrogen purifier.

  According to the present invention, the hydrogen production efficiency of the hydrogen production device can be improved.

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 the modification of 3rd 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 flow path 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.

  An offgas pipe P7A is connected to the raw material supply pipe P1. The off-gas pipe P7A is connected to an off-gas tank 18 described later and supplies the off-gas described later to the preheating passage 24A. The supplied off gas is mixed with city gas and 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 city gas to generate reformed gas containing hydrogen as a main component. The mixed 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 exhaust 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 pressurizes 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.

(Separation part 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.

  The off-gas pipe P7 connected to the outlet side of the off-gas tank 18 is branched into off-gas pipes P7A and P7B. The off-gas pipe P7B is connected to the burner 22 (see FIG. 2) of the multi-cylinder reformer 12, and the off-gas flowing through the off-gas pipe P7B is supplied to the burner 22.

  The off-gas pipe P7A is joined with the raw material supply pipe P1, and the off-gas flowing through the off-gas pipe P7A is supplied to the preheating channel 24A together with the raw material. A flow rate adjusting valve 48 is provided in the off gas pipe P7A, and the flow rate of the off gas branched from the off gas pipe P7 to the off gas pipe P7A is adjusted. The adjustment of the off gas flow rate by the flow rate adjustment valve 48 is performed according to the temperature inside the multi-cylinder reformer 12, the internal pressure of the off gas tank 18, and the like. For example, since the off gas for combustion is required when the hydrogen production device 10A is started, it is possible to control the flow rate of the off gas branched to the off gas pipe P7A to be reduced or set to zero. Further, when the temperature in the multi-cylinder reformer 12 becomes higher than a predetermined steady temperature, control can be performed to increase the flow rate of the off gas branched from the off gas pipe P7 to the off gas pipe P7A. it can. In addition, by making the flow rate of the off gas sent to the off gas pipe P7 constant, the flow rate of the off gas branched to the off gas pipe P7B also changes as the flow rate of the off gas branched from the off gas pipe P7 to the off gas pipe P7A increases or decreases. .

(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 set to be 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.

  During the hydrogen production operation, city gas and reforming water are supplied from the raw material supply pipe P1 to the multi-cylinder reformer 12. Further, the amount of offgas adjusted by the flow rate adjusting valve 48 is supplied to the multi-cylinder reformer 12 from the offgas pipe P7A. In the preheating channel 24A, the city gas, the reforming water, and the off gas are heated while being mixed with each other to be a mixed gas and supplied to the reforming catalyst layer 24C.

  In the reforming catalyst layer 24C, the mixed gas undergoes steam reforming by receiving heat from the combustion exhaust gas flowing through the combustion exhaust gas passage 23, and reformed gas containing hydrogen as a main component is generated. The reformed gas also contains hydrogen gas in the off gas. 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-pressurized 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 unit 32 via the heat exchanger H2. The water vapor contained in the reformed gas supplied to the gas chamber 32A is condensed by cooling in the heat exchanger H2, stored in the liquid chamber 32B, and sent 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 hydrogen gas and off gas containing impurities, and the hydrogen gas is sent to the hydrogen supply pipe P11. The sent hydrogen gas is stored in a tank (not shown) or sent to a hydrogen supply line.

  On the other hand, the offgas containing impurities other than hydrogen separated from the reformed gas flows through the offgas pipe P7 and is temporarily stored in the offgas tank 18. The off gas sent from the off gas tank 18 is branched by the off gas pipes P7A and P7B, and the off gas flowing through the off gas pipe P7A is supplied to the preheating passage 24A of the multi-cylinder reformer 12. The off gas flowing through the off gas pipe P7B 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.

  The off-gas supplied to the preheating flow path 24A is mixed with the city gas and the reforming water to be heated, becomes a mixed gas, is supplied to the reforming catalyst layer 24C, and is reformed as described above.

  In the hydrogen production device 10A of the present embodiment, a part of the offgas containing impurities sent from the hydrogen purifier 16 is supplied to the upstream side of the reforming catalyst layer 24C of the multi-cylinder reformer 12, so the offgas The hydrogen can be obtained by reforming the unreformed raw material contained in 1 again. Further, the hydrogen gas contained in the off gas is sent to the hydrogen purifier 16 again for purification together with the reformed gas reformed in the multi-cylinder reformer 12, so that product hydrogen can be obtained from the off gas. Therefore, the hydrogen production efficiency can be improved.

  In the present embodiment, the off-gas is burned in the combustion section 21 to obtain the heat required for the reforming. However, if there is usable exhaust heat or the like, the exhaust heat may be used as the heat source for the reforming. , Other heat sources may be used.

<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, an offgas pipe P7A branched from the offgas pipe P7 is connected to the communication flow passage pipe P4. In the present embodiment, the configuration other than the connection of the offgas pipe P7A is the same as that of the first embodiment.

  The downstream end of the off-gas pipe P7A is joined and connected to the communication flow pipe P4, and the off-gas whose flow rate is adjusted by the flow rate adjusting valve 48 is on the downstream side of the multi-cylinder reformer 12 and on the upstream side of the compressor 14. Supplied to the side.

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

  During the hydrogen production operation, the city gas and the reforming water are supplied from the raw material supply pipe P1 to the multi-cylinder reformer 12, and the steam reforming of the raw material is performed as in the first embodiment. In the present embodiment, the mixed gas does not include offgas.

  The reformed gas sent from the multi-cylinder reformer 12 to the reformed gas discharge pipe P3 passes through the heat exchanger H1 and the pre-pressurizing water separation unit 30, merges with the off gas, and is supplied to the compressor 14. The off gas and the reformed gas are compressed by the compressor 14, and are supplied to the hydrogen purifier 16 via the post-pressurization water separation unit 32 as in the first embodiment. Then, in the hydrogen purifier 16, the reformed gas is separated into hydrogen gas and off-gas containing impurities.

  The off gas flows through the off gas pipe P7 and is temporarily stored in the off gas tank 18. The off gas sent from the off gas tank 18 is branched by the off gas pipes P7A and P7B. The off gas branched to the off gas pipe P7B is supplied to the burner 22 of the multi-cylinder reformer 12. The off-gas split into the off-gas pipe P7A merges with the reformed gas in the communication flow pipe P4, and is supplied to the hydrogen purifier 16 together with the reformed gas and purified as described above.

  In the hydrogen production apparatus 10B of the present embodiment, a part of the offgas containing impurities sent from the hydrogen purifier 16 is supplied to the downstream side of the multi-cylinder reformer 12 and the upstream side of the compressor 14. Therefore, boosting pressure suitable for the refining process in the hydrogen purifier 16 can be applied to the offgas.

<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 separator 54 is provided in an off gas pipe P7A branched from the off gas pipe P7. In the present embodiment, the configuration other than the carbon dioxide separator 54 and its connection is the same as in the second embodiment.

  A carbon dioxide separator 54 is connected to the off-gas pipe P7A separated from the off-gas pipe P7, downstream of the flow rate adjusting valve 48. The carbon dioxide separator 54 separates the carbon dioxide gas from the off gas. As the carbon dioxide separator 54, a carbon dioxide separation membrane or the like can be used. The separated carbon dioxide gas is sent to the carbon dioxide pipe P14. The carbon dioxide pipe P14 is deployed outside the system of the hydrogen production device 10C for recovery and other purposes. It is joined with the offgas pipe P7B. The off gas (branch off gas) after the carbon dioxide gas is separated is joined from the carbon dioxide separator 54 through the joining pipe P15 and the communication flow passage pipe P4.

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

  During the hydrogen production operation, the city gas and the reforming water are supplied from the raw material supply pipe P1 to the multi-cylinder reformer 12, and the steam reforming of the raw material is performed as in the first embodiment. In this embodiment, the mixed gas does not include offgas.

  The reformed gas sent from the multi-cylinder reformer 12 to the reformed gas discharge pipe P3 is combined with the off gas through the heat exchanger H1 and the pre-pressurizing water separation unit 30, and is supplied to the compressor 14. The off gas and the reformed gas are compressed by the compressor 14 and are supplied to the hydrogen purifier 16 via the post-pressurization water separation unit 32 as in the first embodiment. Then, in the hydrogen purifier 16, the reformed gas is separated into hydrogen gas and off-gas containing impurities.

  The off gas flows through the off gas pipe P7 and is temporarily stored in the off gas tank 18. The off gas sent from the off gas tank 18 is branched by the off gas pipes P7A and P7B. The off gas branched to the off gas pipe P7B is supplied to the burner 22 of the multi-cylinder reformer 12.

  The off-gas that has been split into the off-gas pipe P7A is separated into carbon dioxide by the carbon dioxide separator 54. The separated carbon dioxide is sent to the carbon dioxide pipe P14, and is expanded outside the system of the hydrogen production device 10C for recovery and other purposes. Thereby, the separated carbon dioxide can be effectively used, and a system with high energy saving can be obtained. The branched off-gas after the carbon dioxide is separated is sent from the carbon dioxide separator 54 to the merging pipe P15 and merges with the reformed gas in the connecting flow pipe P4. Then, as described above, the hydrogen is supplied to the hydrogen purifier 16 together with the reformed gas for purification.

  In the hydrogen production apparatus 10C of the present embodiment, the off gas containing impurities that has been sent out from the hydrogen purifier 16 is branched off gas after carbon dioxide is separated from the multi-tube reformer 12 on the downstream side and the compressor. Supply upstream from 14. Therefore, a gas having a hydrogen concentration higher than that of the off-gas before separating carbon dioxide can be combined with the reformed gas and supplied to the hydrogen purifier 16, and the hydrogen purifier 16 can efficiently perform hydrogen purification. You can

  The merging pipe P15 of the present embodiment may be merged with the raw material supply pipe P1 as in the hydrogen purifier 10D shown in FIG. In this case, hydrogen gas can be obtained by reforming the unreformed raw material contained in the branched off gas again.

10A, 10B, 10C, 10D Hydrogen production device 12 Multiple cylinder reformer (reformer)
14 Compressor 16 Hydrogen Purifier 18 Off-gas Tank 21 Combustion Part 54 Carbon Dioxide Separator (Carbon Dioxide Separation Part)
P7 off-gas pipe (off-gas passage)
P7A off-gas pipe (off-gas supply section for re-refining)
P7B Off-gas pipe (combustion gas supply part)
P11 Hydrogen supply pipe (hydrogen gas passage)
P15 confluence pipe (off-gas supply section for re-refining)

A hydrogen producing apparatus according to claim 1 separates the reformer that reforms a raw material to produce a reformed gas containing hydrogen as a main component, and the reformed gas into an off gas containing hydrogen gas and impurities, A hydrogen purifier that delivers the off gas to the off gas passage and delivers the hydrogen gas to the hydrogen gas passage, and a flow path between the reformer and the hydrogen refiner are provided to boost the reformed gas. A compressor to
A water separator provided upstream of the compressor and downstream of the reformer, for separating water from the reformed gas delivered from the reformer, and the offgas delivered to the offgas passage. And a re-refining off-gas supply unit that joins the reformed gas on the upstream side of the compressor and the downstream side of the water separation unit and directly or indirectly supplies the reformed gas to the hydrogen purifier. .

In the hydrogen producing apparatus according to claim 3 , the reformer includes a combustion unit that burns a combustible gas, and a combustion gas supply unit that supplies the off gas sent to the off gas passage to the combustion unit. .

According to the hydrogen production device of the third aspect , the off gas can be used as the heat source of the reformer by supplying the off gas to the combustion section of the reformer.

In the hydrogen production device according to the fourth aspect , the off gas is combined with the raw material. The off-gas and the raw material may be merged on the merged side of the reformer or in the reformer. By thus joining the offgas with the raw material, the unreformed raw material gas contained in the offgas can be reformed by the reformer.

In the hydrogen producing apparatus according to claim 1 , a compressor that pressurizes the reformed gas is provided in a flow path between the reformer and the hydrogen purifier, and the re-refining off-gas supply unit includes: The off gas is combined with the reformed gas on the upstream side of the compressor and the downstream side of the reformer.

In the hydrogen production device according to the first aspect , since the offgas joins with the reformed gas on the upstream side of the compressor, the offgas can be pressurized to be suitable for the refining process in the hydrogen purifier.

A hydrogen generator according to claim 2 separates a reformer that reforms a raw material to generate a reformed gas containing hydrogen as a main component, and the reformed gas into a hydrogen gas and an off-gas containing impurities, A hydrogen purifier that delivers the off-gas to the off-gas passage and also delivers the hydrogen gas to the hydrogen gas passage, and a re-refining that directly or indirectly supplies the off-gas delivered to the off-gas passage to the hydrogen purifier. An off-gas supply unit is provided, and the re-purification off-gas supply unit is configured to include a carbon dioxide separation unit that separates carbon dioxide gas from the off gas, and after carbon dioxide is separated by the carbon dioxide separation unit. After separation of carbon dioxide, off-gas is supplied to the hydrogen purifier.

In the hydrogen production apparatus according to the second aspect , carbon dioxide is separated from the off gas by the carbon dioxide separation unit, and the off gas is supplied to the hydrogen purifier after the carbon dioxide separation. Since off-gas after carbon dioxide separation has a higher hydrogen concentration than off-gas, it is possible to efficiently perform the refining process in the hydrogen purifier.

Claims (5)

A reformer that reforms a raw material to generate a reformed gas containing hydrogen as a main component;
A hydrogen purifier that separates the reformed gas into hydrogen gas and off-gas containing impurities, sends the off-gas to an off-gas passage, and sends the hydrogen gas to the hydrogen gas passage,
A re-refining off-gas supply unit that directly or indirectly supplies the off-gas sent to the off-gas passage to the hydrogen purifier,
Hydrogen generator equipped with. The reformer has a combustion unit that burns a combustible gas,
A combustion gas supply unit configured to supply the off gas sent to the off gas passage to the combustion unit,
The hydrogen production apparatus according to claim 1.   The hydrogen production apparatus according to claim 1 or 2, wherein the re-refining off-gas supply unit merges the off-gas with the raw material. A compressor for pressurizing the reformed gas is provided in a flow path between the reformer and the hydrogen purifier,
The hydrogen according to claim 1 or 2, wherein the re-refining off-gas supply unit merges the off-gas with the reformed gas on the upstream side of the compressor and on the downstream side of the reformer. Manufacturing equipment. The re-refining off-gas supply unit is configured to include a carbon dioxide separation unit that separates carbon dioxide gas from the off-gas,
The hydrogen production device according to any one of claims 1 to 4, wherein the off-gas after carbon dioxide separation after the carbon dioxide is separated in the carbon dioxide separation unit is supplied to the hydrogen purifier.