JP6530123B1 - Hydrogen production equipment - Google Patents

Abstract

An object of the present invention is to provide a hydrogen production apparatus that improves hydrogen production efficiency. In a hydrogen production apparatus (10A), a reformed gas is separated into a hydrogen gas and an off gas containing impurities in a hydrogen purifier (16). The off gas containing impurities is delivered to the off gas path P7, joined with the reformed gas, again supplied to the hydrogen purifier 16, and repurified. [Selected figure] Figure 1

Description

  The present invention relates to a hydrogen production apparatus.

  Conventionally, as a hydrogen production apparatus for obtaining hydrogen, one that reforms raw material hydrocarbons into a reformed gas with a reformer and then supplies it to a PSA (Pressure Swing Adsorption) apparatus is known (for example, a patent) Reference 1). In the hydrogen production apparatus of Patent Document 1, reforming water is supplied to a reformer together with city gas, steam reforming is performed to generate a reforming gas containing hydrogen, and the reforming gas is purified by a hydrogen purifier. Produces high purity product hydrogen.

JP, 2017-88490, A

  By the way, in patent document 1, the off gas containing the impurity discharged | emitted when refine | purifying reformed gas with a hydrogen purifier is supplied to the burner of a reformer, and it is utilized as a fuel. At present, the off gas contains hydrogen gas, and if the amount of hydrogen gas is large, the ratio of product hydrogen water that can be produced to the raw material is low, and the hydrogen production efficiency is lowered.

  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 improves the hydrogen production efficiency.

The hydrogen production apparatus according to claim 1 separates the reformed gas into a hydrogen gas and an off gas containing an impurity, and a reformer that reforms the raw material and generates a reformed gas mainly composed of hydrogen, A hydrogen purifier for delivering the off gas to the off gas path and delivering the hydrogen gas to the hydrogen gas path, and a flow path between the reformer and the hydrogen purifier, for boosting the reformed gas The compressor to
A water separation unit provided upstream of the compressor and downstream of the reformer, for separating water from the reformed gas sent from the reformer, and the off gas sent to the off gas passage And a repurification off-gas supply unit which is combined with the reformed gas on the upstream side of the compressor and on the downstream side of the water separation unit to directly or indirectly supply the hydrogen purifier. .

  The hydrogen production apparatus according to claim 1 includes a reformer and a hydrogen purifier. The offgas including the impurities separated by the hydrogen purifier and delivered to the offgas path is supplied to the hydrogen purifier by the repurification offgas supply unit. The offgas supply to the hydrogen purifier by the repurification offgas supply unit may be direct supply or may be indirect supply after being processed by passing through other devices and the like. Product hydrogen can be obtained from the off gas by separating the off gas into hydrogen gas and an off gas containing impurities in a hydrogen purifier. Thereby, hydrogen production efficiency can be improved.

The hydrogen production apparatus according to claim 3 , wherein the reformer has a combustion unit that burns combustible gas, and has a combustion gas supply unit that supplies the off gas delivered to the off gas passage to the combustion unit. .

According to the hydrogen production apparatus of the third aspect , by supplying the off gas to the combustion unit of the reformer, it can be used as a heat source of the reformer.

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

In the hydrogen production apparatus according to claim 4 , the off gas is merged with the raw material. The merging of the off gas and the raw material may be on the merging side of the reformer or may be in the reformer. Thus, the unreformed raw material gas contained in the off gas can be reformed by the reformer by combining the off gas with the raw material.

In the hydrogen production apparatus according to claim 1 , a compressor for pressurizing the reformed gas is provided in a flow path between the reformer and the hydrogen purifier, and the repurification off gas supply unit is The off-gas is merged with the reformed gas upstream of the compressor and downstream of the reformer.

In the hydrogen production apparatus according to the first aspect , the off gas merges with the reformed gas on the upstream side of the compressor, so that the pressure increase suitable for the purification process in the hydrogen purifier can be applied to the off gas.

The hydrogen production apparatus according to claim 2 separates the reformed gas into a hydrogen gas and an off gas containing an impurity, and a reformer that reforms the raw material and generates a reformed gas mainly composed of hydrogen, A hydrogen purifier that delivers the off gas to the off gas path and a hydrogen purifier that delivers the hydrogen gas to the hydrogen gas path, and a repurification source that directly or indirectly supplies the off gas sent to the off gas path to the hydrogen purifier An off-gas supply unit, the re-purification off-gas supply unit including a carbon dioxide separation unit separating carbon dioxide gas from the off gas, the carbon dioxide separation unit separating the carbon dioxide in the carbon dioxide separation unit; After carbon dioxide separation, an off gas is supplied to the hydrogen purifier.

In the hydrogen production apparatus according to claim 2 , carbon dioxide is separated from the off gas by the carbon dioxide separation unit, and the carbon dioxide separated off gas is supplied to the hydrogen purifier. In the off gas after carbon dioxide separation, since the hydrogen concentration is higher than the off gas, the purification process can be efficiently performed by the hydrogen purifier.

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

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

First Embodiment
An example of a hydrogen production apparatus according to a first embodiment of the present invention will be described according to FIGS. 1 and 2.

  The hydrogen production apparatus 10A according to the present embodiment, as shown in FIG. 1, includes a multi-cylinder reformer 12, a compressor 14, a hydrogen purifier 16, and an off gas tank 18. Further, the pre-pressurization water separation unit 30, the post-pressurization water separation unit 32, and the combustion exhaust gas water separation unit 34 are provided. The hydrogen production apparatus 10A produces hydrogen from a hydrocarbon raw material, and in the present embodiment, a case where a town gas mainly composed of methane 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, and 20D arranged in multiples. The plurality of cylindrical walls 20A, 20B, 20C, and 20D are formed in, for example, a cylindrical shape or an elliptical cylindrical shape. A combustion portion 21 which is a combustion space is formed in the first cylindrical wall 20A from the inner side among the plurality of cylindrical walls 20A, 20B, 20C, and 20D. A combustion exhaust gas flow passage 23 is formed between the first cylindrical wall 20A and the second cylindrical wall 20B. Moreover, the 1st flow path 24 is formed between the 2nd cylindrical wall 20B and the 3rd cylindrical wall 20C. Furthermore, a second flow passage 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 other forms of reformer may be used.

  An upper portion of the first flow passage 24 is formed as a preheating flow passage 24A, and a spiral member 24B is provided in the preheating flow passage 24A. The preheating flow path 24A is formed in a spiral shape by the spiral member 24B. A raw material supply pipe P1 for supplying a city gas as a raw material and a reforming water supply pipe P9 for supplying reforming water are connected to an upper end portion of the preheating flow path 24A. To the preheating flow path 24A, the city gas is supplied from the raw material supply pipe P1, and the reforming water is supplied from the reforming water supply pipe P9. The city gas and the reforming 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 flow path 24A, a mixed gas is generated by mixing the city gas and the reforming water (steam) in the gas phase.

  In addition, in this embodiment, although city gas is used as a raw material, if it is a gas which can be steam-reformed, it will not be specifically limited, A hydrocarbon fuel can be used. Examples of hydrocarbon fuels include natural gas, LP gas (liquefied petroleum gas), coal reformed gas, and lower hydrocarbon gas.

  Further, an off gas 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 an off gas described later to the preheating flow path 24A. The supplied off gas is mixed with the city gas and the reforming water and flows through the preheating flow path 24A.

  A reforming catalyst layer 24C is provided below the preheating flow path 24A in the first flow path 24. The reforming catalyst layer 24C is provided with a catalyst for steam reforming city gas to generate a reformed gas containing hydrogen as a main component. The mixed gas generated in the preheating flow path 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 a reforming gas containing hydrogen as a main component is generated by the steam reforming reaction and the carbon dioxide reforming reaction.

  The second flow path 25 is disposed radially outside the first flow path 24, and the lower end portion of the second flow path 25 is in communication with the lower end portion of the first flow path 24. In the second flow path 25, a CO shift catalyst layer 26 and a CO selective oxidation catalyst layer 27 are formed at positions corresponding to the preheating flow path 24A. In the CO shift catalyst layer 26, carbon monoxide and steam contained in the reformed gas react with each other to convert them into hydrogen and carbon dioxide, thereby reducing carbon monoxide.

  The CO selective oxidation catalyst layer 27 is disposed downstream of the CO shift catalyst layer 26. Between the CO shift catalyst layer 26 and the CO selective oxidation catalyst layer 27, an oxidant gas supply pipe P2B for supplying an oxidant gas is connected. In the CO selective oxidation catalyst layer 27, carbon monoxide is reacted with oxygen to be converted to carbon dioxide, and carbon monoxide is removed. A reformed gas discharge pipe P3 is connected to the upper end portion of the second flow path 25 on the downstream side of the CO selective oxidation catalyst layer 27. The reformed gas is delivered from the reformed gas discharge pipe P3 after 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 not be provided. In this case, the oxidant gas supply pipe P2B is also unnecessary.

  A burner 22 is disposed downward at the top of the combustion unit 21. An off gas pipe P7 is connected to the burner 22, and an off gas described later is supplied as a fuel from the off gas pipe P7. Further, an air supply pipe P2 for supplying combustion air is connected to an upper end portion of the combustion unit 21. The burner 22 is further connected to a raw material branch pipe P1A branched from the raw material supply pipe P1. 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 the city gas is mixed with air is supplied to the burner 22 separately from the off gas. One or both of the offgas for combustion and the city gas are supplied as needed.

  The combustion exhaust gas passage 23 is formed on the radially outer side of the combustion unit 21, and the lower end portion of the combustion exhaust gas passage 23 is in communication with the combustion unit 21. A gas discharge pipe P10 for discharging a gas is connected to an upper end portion of the combustion exhaust gas flow path 23. The gas discharge pipe P <b> 10 is connected to the upper end surface of the multi-cylinder reformer 12. The combustion exhaust gas discharged from the combustion section 21 flows upward from the lower side of the combustion exhaust gas flow path 23 and is discharged to the outside of the multi-tube reformer 12 through the gas discharge pipe P10.

  The reformed gas delivered 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 The hydrogen purifier 16 flows in this order. That is, in the gas flow direction, from the upstream side to the downstream side, the multi-cylinder reformer 12, the pre-pressurized water separation unit 30, the compressor 14, the post-pressurized water separation unit 32, and the hydrogen purifier 16 are arranged in this order It is arranged.

(Separating part before boosting)
The upper part of the pre-pressurized water separation unit 30 is a gas chamber 30A, and the lower part is 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 passage 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 water vapor in the reformed gas is condensed by being cooled in the heat exchanger HE1 disposed upstream of the pre-pressurization water separation unit 30. The water separated from the reformed gas by condensation is stored in the liquid chamber 30B and delivered to the reformed gas water pipe P8A.

(Compressor)
Connected to the compressor 14 are a communication flow path pipe P4 through which the reformed gas from the pre-pressurization water separation unit 30 flows and a communication flow path pipe P5 through which the reforming gas supplied to the post-pressurization water separation unit 32 flows. ing. The compressor 14 compresses and boosts 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.

(Separated part after boosting)
The upper part of the post-pressurized water separation unit 32 is a gas chamber 32A, and the lower part is a liquid chamber 32B. The downstream end of the communication passage pipe P5 is connected to the gas chamber 32A. Further, the upstream end of the communication passage 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 water vapor in the reformed gas is condensed by being cooled in a heat exchanger HE2 disposed upstream of the water separation unit 32 after pressure increase. The water separated from the reformed gas by condensation is stored in the liquid chamber 32B and delivered to a reformed gas water pipe P8B.

  A buffer tank 36 is provided downstream of the post-pressurized water separation unit 32 and upstream of the hydrogen purifier 16. The buffer tank 36 accumulates the reformed gas supplied from the post-pressurized water separation unit 32. The reformed gas once accumulated in the buffer tank 36 is delivered to the hydrogen purifier 16.

(Hydrogen purifier)
The hydrogen purifier 16 is connected to the downstream end of the communication flow pipe P6 through which the reformed gas from the post-pressurized water separation unit 32 flows. For the hydrogen purifier 16, a PSA device is used as an example. By separating the reformed gas into impurities and hydrogen by the hydrogen purifier 16, hydrogen is purified. A hydrogen supply pipe P11 is connected to the hydrogen purifier 16. The purified hydrogen is delivered to the hydrogen supply pipe P11, stored in a tank (not shown), or delivered to a hydrogen supply line.

  The hydrogen purifier 16 is connected to the upstream end of the off gas pipe P7. The downstream end of the off gas pipe P7 is connected to the burner 22 of the multi-cylinder reformer 12. The hydrogen purifier 16 delivers the off gas separated by hydrogen purification to the off gas pipe P7. An off gas tank 18 is provided in the off gas 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 flow path 24A together with the raw material. The off gas pipe P7A is provided with a flow control valve 48, and the flow rate of the off gas branched from the off gas pipe P7 to the off gas pipe P7A is adjusted. Adjustment of the off gas flow rate by the flow rate adjustment valve 48 is performed according to the temperature in the multi-cylinder reformer 12, the internal pressure of the off gas tank 18, and the like. For example, since the offgas for combustion is required at the start of the hydrogen production apparatus 10A, control can be performed to reduce or zero the flow rate of the offgas branched to the off gas pipe P7A. Further, when the temperature in the multi-cylinder reformer 12 becomes higher than a predetermined steady-state temperature, control is 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. The flow rate of the off gas branched to the off gas pipe P7B also changes with the increase or decrease of the flow rate of the off gas branched from the off gas pipe P7 to the off gas pipe P7A by making the flow rate of the off gas sent to the off gas pipe P7 constant. .

(Combustion exhaust water separation unit)
The upper part of the combustion exhaust gas water separation part 34 is a gas chamber 34A, and the lower part is a liquid chamber 34B. The downstream end of the gas discharge pipe P10 is connected to the gas chamber 34A. Further, an external discharge pipe P12 is connected to the gas chamber 34A. A water delivery port 34C is formed at the bottom of the liquid chamber 34B, and a flue gas water pipe P8C is connected to the water delivery port 34C. The combustion exhaust 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 water separation unit 34 is disposed 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 disposed 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 vertically above the bottom of the liquid chamber 32B. The bottom of the liquid chamber 34B is preferably disposed vertically above the upper ends of the pre-pressurized water separation unit 30 and the post-pressurized water separation unit 32.

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

  The combustion exhaust gas is delivered from the combustion unit 21 to the gas discharge pipe P10 through the combustion exhaust gas flow path 23. The steam in the combustion exhaust gas is condensed by being cooled in the heat exchanger HE3 disposed 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 is delivered to the combustion exhaust water pipe P8C. The combustion exhaust gas after water is separated is discharged to the outside from the external discharge pipe P12.

  A water tank 40 is disposed at the bottom of the hydrogen production apparatus 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 flue gas water pipe P8C are connected to the water inlet 40A after merging. The pipe after merging 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 water pipe P8C.

  The water tank 40 has a larger capacity than the total amount of water that can be stored in the pre-pressurized water separation unit 30, post-pressurized water separation unit 32, and the combustion exhaust gas water separation unit 34. It is disposed below the rear water separation unit 32 and the combustion exhaust water separation unit 34 in the vertical direction. Here, “the water tank 40 is disposed vertically lower than the pre-pressurized water separation unit 30, post-pressurized water separation unit 32, and the combustion exhaust water separation unit 34” means that the bottom of the liquid chamber 30B is This means that the bottom of the liquid chamber 32B and the bottom of the liquid chamber 34B are disposed vertically above the water inlet 40A of the water tank 40.

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

(Action)
Next, the operation of the hydrogen production apparatus 10A 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-tubular reformer 12. Further, the amount of off gas adjusted by the flow rate adjustment valve 48 is supplied from the off gas pipe P7A to the multi-cylinder reformer 12. The city gas, the reforming water, and the off gas are mixed while being heated in the preheating flow path 24A, and the mixed gas 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 flue gas flowing through the flue gas flow path 23, and a reformed gas mainly composed of hydrogen 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 flow path 25. In the CO shift catalyst layer 26, carbon monoxide and steam contained in the reformed gas react with each other to convert them into hydrogen and carbon dioxide, thereby reducing carbon monoxide. The reformed gas that has passed through the CO shift 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. It is converted to carbon dioxide and carbon monoxide is removed. The reformed gas whose carbon monoxide has been reduced by the CO selective oxidation catalyst layer 27 is delivered 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 through the heat exchanger H1 provided in the reformed gas discharge pipe P3. Water contained in the reformed gas supplied to the gas chamber 30A is condensed by cooling in the heat exchanger H1 and stored in the liquid chamber 30B, and is delivered to the water tank 40 through the reformed gas water pipe P8A. From the gas chamber 30A, the reformed gas from which water has been separated flows through the communication flow pipe P4, is supplied to the compressor 14, and is compressed by the compressor 14.

  The compressed reformed gas flows through the communication flow pipe P6, passes through the heat exchanger H2, and is supplied to the gas chamber 32A of the water separation unit 32 after pressure increase. The water vapor contained in the reformed gas supplied to the gas chamber 32A is condensed by cooling in the heat exchanger H2 and stored in the liquid chamber 32B, and is delivered to the water tank 40 through the reformed gas water pipe P8B. From the gas chamber 32A, the reformed gas from which water has been separated is supplied to the hydrogen purifier 16 through the communication passage pipe P6.

  In the hydrogen purifier 16, the reformed gas is separated into hydrogen gas and off gas containing impurities, and the hydrogen gas is delivered to the hydrogen supply pipe P11. The delivered hydrogen gas 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 P 7 and is temporarily stored in the off gas tank 18. The off gas delivered 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 flow path 24A of the multi-cylinder reformer 12. The off gas flowing through the off gas pipe P7B is supplied to the burner 22 of the multi-cylinder reformer 12 as a fuel.

  In the combustion section 21 of the multi-cylinder reformer 12, the off gas is burned, and the combustion exhaust gas is supplied to the gas chamber 34A of the combustion exhaust water separator 34 via the gas discharge pipe P10. The steam contained in the flue gas supplied to the gas chamber 34A is condensed by cooling in the heat exchanger H3 and stored in the liquid chamber 34B, and is delivered to the water tank 40 through the flue 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 and heated, and is supplied to the reforming catalyst layer 24C as a mixed gas, and is reformed as described above.

  In the hydrogen production apparatus 10A of the present embodiment, a part of the off gas 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 off gas The unreformed raw material contained in can be reformed again to obtain hydrogen. In addition, since the hydrogen gas contained in the off gas is again delivered to the hydrogen purifier 16 together with the reformed gas reformed by the multi-cylinder reformer 12 and purified, the product hydrogen can be obtained from the off gas. 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 necessary for reforming, but if there is usable exhaust heat, etc., 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. About the part similar to 1st Embodiment, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  In the hydrogen production apparatus 10B of this embodiment, as shown in FIG. 3, an off gas pipe P7A branched from an off gas pipe P7 is connected to the communication flow path pipe P4. In the present embodiment, the configuration other than the connection of the off gas pipe P7A is the same as that of the first embodiment.

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

(Action)
Next, the operation of the hydrogen production apparatus 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-tubular reformer 12, and steam reforming of the raw material is performed as in the first embodiment. In the present embodiment, the mixed gas does not include the off gas.

  The reformed gas delivered from the multi-cylinder reformer 12 to the reformed gas discharge pipe P3 passes through the heat exchanger H1 and the pre-pressurization water separation unit 30, is merged with the off gas, and is supplied to the compressor. The off gas and the reformed gas are compressed by the compressor 14 and are supplied to the hydrogen purifier 16 through the post-pressurized 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 P 7 and is temporarily stored in the off gas tank 18. The off gas delivered from the off gas tank 18 is branched off by 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 divided into the off gas pipe P7A joins 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 off gas 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, a pressure increase suitable for the purification process in the hydrogen purifier 16 can be applied to the off gas.

Third Embodiment
Next, a third embodiment of the present invention will be described. About the part similar to 1st, 2nd embodiment, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  In the hydrogen production apparatus 10C of the present embodiment, as shown in FIG. 4, a carbon dioxide separation device 54 is provided in the 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 the connection thereof is the same as that of the second embodiment.

  A carbon dioxide separator 54 is connected downstream of the flow control valve 48 of the off gas pipe P7A separated from the off gas pipe P7. The carbon dioxide separator 54 separates carbon dioxide gas from the off gas. A carbon dioxide separation membrane or the like can be used as the carbon dioxide separation device 54. The separated carbon dioxide gas is delivered to the carbon dioxide pipe P14. The carbon dioxide pipe P14 is expanded out of the system of the hydrogen production apparatus 10C for recovery, other uses, and the like. It joins with off gas pipe P7B. The off gas (branch off gas) after the carbon dioxide gas is separated is merged with the communication flow path pipe P4 from the carbon dioxide separator 54 through the merging pipe P15.

(Action)
Next, the operation of the hydrogen production apparatus 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-tubular reformer 12, and steam reforming of the raw material is performed as in the first embodiment. In the present embodiment, the mixed gas does not contain an off gas.

  The reformed gas delivered from the multi-cylinder reformer 12 to the reformed gas discharge pipe P3 passes through the heat exchanger H1 and the pre-pressurization water separation unit 30, is merged with the off gas, and is supplied to the compressor. The off gas and the reformed gas are compressed by the compressor 14 and are supplied to the hydrogen purifier 16 through the post-pressurized 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 P 7 and is temporarily stored in the off gas tank 18. The off gas delivered from the off gas tank 18 is branched off by 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 which has been diverted to the off gas pipe P7A is subjected to carbon dioxide separation by the carbon dioxide separation device 54. The separated carbon dioxide is sent to the carbon dioxide pipe P14, and is developed out of the system of the hydrogen production apparatus 10C for recovery, other uses, and the like. Thereby, the separated carbon dioxide can be used effectively, and a system with high energy saving can be obtained. After the carbon dioxide is separated, the branched off gas is delivered from the carbon dioxide separator 54 to the junction pipe P15, and merges with the reformed gas in the communication flow pipe P4. Then, as described above, the hydrogen is supplied to the hydrogen purifier 16 together with the reformed gas and purified.

  In the hydrogen production apparatus 10C of the present embodiment, with regard to the off gas containing impurities sent from the hydrogen purifier 16, the branched off gas after separating carbon dioxide is disposed downstream of the multi-cylinder reformer 12 and the compressor Supply upstream than 14. Therefore, a gas having a hydrogen concentration higher than the off gas before separating carbon dioxide can be combined with the reformed gas and supplied to the hydrogen purifier 16, and hydrogen purification can be efficiently performed in the hydrogen purifier 16. Can.

  Note that 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, the unreformed raw material contained in the branched off gas can be reformed again to obtain hydrogen gas.

10A, 10B, 10C, 10D Hydrogen production equipment 12 Multi-cylinder reformer (reformer)
14 compressor 16 hydrogen purifier 18 off gas tank 21 combustion unit 54 carbon dioxide separation device (carbon dioxide separation unit)
P7 Off gas pipe (off gas path)
P7A off gas pipe (off gas supply unit for repurification)
P7B off gas pipe (combustion gas supply unit)
P11 Hydrogen supply piping (hydrogen gas passage)
P15 Merger (off gas supply unit for repurification)

Claims (4)

A reformer which reforms the raw material and generates a reformed gas mainly composed of hydrogen;
A hydrogen purifier that separates the reformed gas into hydrogen gas and an off gas containing impurities, and delivers the off gas to an off gas passage and also delivers the hydrogen gas to a hydrogen gas passage;
A compressor provided in a flow path between the reformer and the hydrogen purifier to boost the reformed gas;
A water separation unit provided upstream of the compressor and downstream of the reformer for separating water from the reformed gas delivered from the reformer;
For repurification, the offgas delivered to the offgas path is merged with the reformed gas upstream of the compressor and downstream of the water separation unit and directly or indirectly supplied to the hydrogen purifier An off gas supply unit,
Hydrogen production equipment equipped with A reformer which reforms the raw material and generates a reformed gas mainly composed of hydrogen;
A hydrogen purifier that separates the reformed gas into hydrogen gas and an off gas containing impurities, and delivers the off gas to an off gas passage and also delivers the hydrogen gas to a hydrogen gas passage;
An offgas supply unit for repurification, which directly or indirectly supplies the offgas delivered to the offgas path directly or indirectly to the hydrogen purifier;
Equipped with
The repurification off gas supply unit includes a carbon dioxide separation unit that separates carbon dioxide gas from the off gas.
An off gas after carbon dioxide separation after carbon dioxide separation in the carbon dioxide separation unit is supplied to the hydrogen purifier,
Hydrogen production equipment. The reformer has a combustion unit that burns combustible gas,
A combustion gas supply unit for supplying the offgas delivered to the offgas passage to the combustion unit;
The hydrogen production apparatus according to claim 1 or 2 . The hydrogen production apparatus according to claim 2 , wherein the repurification off gas supply unit merges the off gas with the raw material.