JP2017088488A - Hydrogen production apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen production apparatus which can be downsized, can cope with a change of required quantity of hydrogen production easily, and can prevent composition variation of reformed gas.SOLUTION: A hydrogen production apparatus 10 comprises multiple multiplex barrel reformers 12 and a hydrogen purifier 16. The multiple multiplex barrel reformers 12 are connected in parallel with each other and generate reformed gas containing hydrogen as a main component by reforming hydrocarbon raw materials respectively. The hydrogen purifier 16 is connected to the multiple multiplex barrel reformers 12 and purifies hydrogen by separating the reformed gas generated in the multiple multiplex barrel reformers 12 into impurities and hydrogen.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydrogen production apparatus.

  Conventionally, as a hydrogen production apparatus for obtaining hydrogen, a reformer that reforms a hydrocarbon raw material to generate a reformed gas mainly composed of hydrogen, and a reformed gas generated by the reformer are used. A device having a hydrogen purifier that separates impurities into hydrogen and purifies hydrogen is known (see, for example, Patent Documents 1 and 2).

JP 2001-261306 A JP 2003-335502 A JP 2000-285948 A Japanese Patent No. 5371013

  In the prior arts of Patent Documents 1 and 2, since a reformer is designed exclusively for a hydrogen production apparatus having a large-scale hydrogen production capacity, the hydrogen production apparatus is enlarged.

  Further, in the prior arts of Patent Documents 1 and 2, since there is one reformer, it is difficult to cope with the required change in the hydrogen production amount, and the reforming is performed when the hydrogen consumption varies. Since the reaction conditions of the reactor fluctuate, there is a problem that the composition of the reformed gas fluctuates.

  The present invention has been made in view of the above circumstances, and is a hydrogen production apparatus that can be reduced in size, can easily cope with a required change in the amount of hydrogen production, and can suppress fluctuations in the composition of the reformed gas. The purpose is to provide.

  In the first aspect, a plurality of multi-cylinder reformers and a hydrogen purifier are provided. The plurality of multi-cylinder reformers are connected in parallel to each other, and reform the hydrocarbon raw material to generate reformed gas mainly containing hydrogen. The hydrogen purifier is connected to the plurality of multi-cylinder reformers, and purifies hydrogen by separating the reformed gas generated in the plurality of multi-cylinder reformers into impurities and hydrogen. To do.

  According to this hydrogen production apparatus, since the multi-cylinder reformer is used as the reformer, the entire apparatus can be reduced in size.

  Moreover, since a plurality of multi-cylinder reformers are provided in parallel to the hydrogen purifier, it is possible to easily cope with a required change in the amount of hydrogen production by adjusting the number of reformers.

  In addition, if you want to change the supply amount of hydrogen to the supply target, it is only necessary to adjust the number of operation of the multi-cylinder reformer, the reaction conditions of each reformer can be kept constant, Variations in gas composition can be suppressed.

  In the second aspect, a judgment means for judging whether or not preparation for an increase in production after a reduction in the amount of hydrogen purification is necessary, a suppression means executed when preparation for an increase in production is necessary, and a process executed when preparation for an increase in production is not required. And stop means. When preparation for increasing production after reducing the amount of hydrogen purified is necessary, the amount of reformed gas produced by the multi-cylinder reformer is suppressed by the suppression means to reduce the amount purified. In addition, when preparation for increasing production after the reduction of the amount of hydrogen purification is not required, some of the multi-tubular reformers are stopped by the stopping means to reduce the amount of purification.

  According to the hydrogen production apparatus of the second aspect, when preparation for increase in production is necessary based on the prediction of change in the hydrogen supply amount after the decrease in production volume, the multi-tubular reformer in operation is maintained while maintaining operation. Since the production amount of quality gas is suppressed, the followability at the time of production increase can be improved.

  On the other hand, if it is not necessary to prepare for increased production based on the prediction of changes in the hydrogen supply after the decrease in production, some of the multi-cylinder reformers are stopped to reduce the hydrogen production. The cylindrical reformer can be maintained in a state of high hydrogen production efficiency. Thereby, the efficiency fall as a whole can be suppressed.

  Therefore, it is possible to achieve both improvement in hydrogen production efficiency when the amount of hydrogen production is reduced and improvement in followability when increasing production after the reduction.

  In addition, since the multi-cylinder reformer is used, the time required for starting and stopping the individual reformers can be shortened.

  In a third aspect, the determination means determines whether or not preparation for increasing production is necessary based on whether or not an increase in the hydrogen supply amount is predicted within a predetermined time after the purification amount is decreased. If an increase in hydrogen supply is expected within a predetermined time after the decrease in production volume, it is determined that preparation for an increase in production is necessary. If an increase in hydrogen supply is not predicted within a predetermined time, preparation for an increase in production is not necessary. to decide.

  According to the hydrogen production apparatus of the third aspect, when an increase in production is expected immediately after a decrease in production, the amount of reformed gas produced by the multi-cylinder reformer is suppressed. Can increase the sex.

  On the other hand, when it is predicted that the production will not increase for a while after the production amount is reduced, any of the multi-cylinder reformers is stopped to reduce the purified amount of hydrogen, so that a reduction in efficiency can be suppressed.

  According to this aspect, the entire apparatus can be reduced in size, can easily cope with a required change in the amount of hydrogen production, and can suppress fluctuations in the composition of the reformed gas.

It is a figure showing the whole hydrogen production device composition concerning one embodiment of the present invention. It is a figure which shows the detail of the multiple cylinder type | mold reformer shown by FIG. It is a flowchart of the main routine which shows the operation | movement of the embodiment. It is a flowchart which shows the operation | movement of the production reduction process of the embodiment.

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

  As shown in FIG. 1, the hydrogen production apparatus 10 according to the present embodiment includes a plurality of multi-tube reformers (FPS) 12, a compressor 14, a hydrogen purifier 16, and a hydrogen purifier 16. And a flow meter 18 for measuring the supply amount of hydrogen. This hydrogen production apparatus 10 produces hydrogen from a hydrocarbon raw material. This embodiment demonstrates the case where city gas is used as an example of a hydrocarbon raw material.

  The plurality of multi-cylinder reformers 12 are connected in parallel to each other. The plurality of multiple cylindrical reformers 12 are connected to a hydrogen purifier 16 via a compressor 14. The number of the multiple cylindrical reformers 12 can be arbitrarily set according to the required amount of hydrogen production. The plurality of multiple cylindrical reformers 12 have the same configuration.

  As shown in FIG. 2, each multi-cylinder reformer 12 has a plurality of cylindrical walls 21 to 24 arranged in a multiplex manner. The plurality of cylindrical walls 21 to 24 are formed in, for example, a cylindrical shape or an elliptical cylindrical shape. A combustion chamber 25 is formed inside the first cylindrical wall 21 from the inner side among the plurality of cylindrical walls 21 to 24, and a burner 26 is disposed downwardly on the upper portion of the combustion chamber 25. Yes.

  A flue gas flow path 27 is formed between the first cylindrical wall 21 and the second cylindrical wall 22. A lower end portion of the combustion exhaust gas passage 27 communicates with the combustion chamber 25, and a gas exhaust pipe 28 is provided at the upper end portion of the combustion exhaust gas passage 27. The flue gas discharged from the combustion chamber 25 flows from the lower side to the upper side through the flue gas passage 27 and is discharged to the outside through the gas discharge pipe 28.

  A first flow path 31 is formed between the second cylindrical wall 22 and the third cylindrical wall 23. An upper portion of the first flow path 31 is formed as a preheating flow path 32, and a raw material supply pipe 33 and a reforming water supply pipe 34 are connected to an upper end portion of the preheating flow path 32. A spiral member 35 is provided between the second cylindrical wall 22 and the third cylindrical wall 23, and the preheating channel 32 is formed in a spiral shape by the spiral member 35.

  The preheating channel 32 is supplied with city gas from the raw material supply pipe 33, and the supply amount is controlled by a control valve 33a provided in the raw material supply pipe 33 as shown in FIG. Further, as shown in FIG. 2, reforming water is supplied to the preheating channel 32 from a reforming water supply pipe 34 (not shown in FIG. 1). The city gas and the reforming water flow from the upper side to the lower side through the preheating flow path 32, and are heat-exchanged with the combustion exhaust gas through the second cylindrical wall 22 to vaporize the water. In the preheating channel 32, the mixed gas is generated by mixing the city gas and the reforming water (steam) in the gas phase.

  A reforming catalyst layer 36 is provided below the preheating channel 32 in the first channel 31, and the mixed gas generated in the preheating channel 32 is supplied to the reforming catalyst layer 36. In the reforming catalyst layer 36, the mixed gas is steam reformed by receiving heat from the combustion exhaust gas flowing through the combustion exhaust gas passage 27, and a reformed gas mainly containing hydrogen is generated.

  A second flow path 42 is formed between the third cylindrical wall 23 and the fourth cylindrical wall 24. The lower end of the second flow path 42 is in communication with the lower end of the first flow path 31. A lower portion of the second flow path 42 is formed as a reformed gas flow path 43, and a reformed gas discharge pipe 44 is connected to an upper end portion of the second flow path 42.

  A CO shift catalyst layer 45 is provided above the reformed gas channel 43 in the second channel 42, and the reformed gas generated in the reformed catalyst layer 36 is reformed gas channel 43. And then supplied to the CO shift catalyst layer 45. In the CO conversion catalyst layer 45, carbon monoxide and water vapor contained in the reformed gas react to be converted into hydrogen and carbon dioxide, and carbon monoxide is reduced.

  An oxidant gas supply pipe 46 is provided above the CO conversion catalyst layer 45, and a CO removal catalyst layer 47 is provided above the CO conversion catalyst layer 45 in the second flow path 42. The oxidant gas introduced through the oxidant gas supply pipe 46 and the reformed gas that has passed through the CO shift catalyst layer 45 are supplied to the CO removal catalyst layer 47. In the CO removal catalyst layer 47, for example, carbon monoxide reacts with oxygen on a noble metal catalyst such as platinum or ruthenium to be converted into carbon dioxide, and carbon monoxide is removed. The reformed gas from which carbon monoxide has been removed by the CO shift catalyst layer 45 and the CO removal catalyst layer 47 is discharged through the reformed gas discharge pipe 44.

  The reformed gas generated in each multi-cylinder reformer 12 is sent to the compressor 14 shown in FIG. 1 and compressed by the compressor 14. The reformed gas compressed by the compressor 14 is sent to the hydrogen purifier 16.

  As an example, a PSA (Pressure Swing Adsorption) apparatus is used for the hydrogen purifier 16. In the hydrogen purifier 16, the reformed gas is separated into impurities and hydrogen, and the hydrogen is purified. The off gas from the hydrogen purifier 16 contains impurities, and this off gas is used as fuel for the burner 26 (see FIG. 2). When the fuel supplied to the burner 26 is insufficient, the city gas is supplied to the burner 26 from a supply route (not shown).

  As shown in FIG. 1, the gas supply path to the burner 26 is provided with a control valve 26a so that the amount of gas supplied to the burner 26 can be controlled.

  The hydrogen production apparatus 10 described above is applied to, for example, a fuel cell system, and the hydrogen produced by the hydrogen production apparatus 10 is supplied to the fuel cell in the fuel cell system via the flow meter 18 for power generation by the fuel cell. Used.

  In this hydrogen production apparatus 10, for example, when the required hydrogen production amount changes in accordance with the specifications (rated output) of the fuel cell system, it can be dealt with by adjusting the number of multiple cylindrical reformers 12. It is. Further, when it is desired to change the supply amount of hydrogen to the fuel cell in response to the load fluctuation of the fuel cell, it can be dealt with by adjusting the number of operations of the multi-cylinder reformer 12.

  The hydrogen production apparatus 10 includes a control unit 60 that constitutes a determination unit, a suppression unit, and a stop unit. The control unit 60 is connected to the control valve units 26a and 33a and the flow meter 18. Has been. Thereby, the control part 60 controls the opening degree of each control valve part 26a, 33a while inputting the flow volume measured with the flowmeter 18. FIG.

  The control unit 60 is mainly configured with a microcomputer incorporating a ROM and a RAM, and the control unit 60 operates and controls the hydrogen production apparatus 10 when the microcomputer operates according to a program stored in the ROM.

  FIG. 3 is a flowchart showing the operation of the control unit 60, and shows a part related to control of the amount of hydrogen to be purified. The operation of the hydrogen production apparatus 10 will be described according to this flowchart.

  That is, when the control unit 60 starts operation, the flow rate is input from the flow meter 18 (S1), and this flow rate is associated with the date and time and stored as an operation history in storage means such as a RAM (S2). Thereby, the temporal change of the hydrogen supply amount is recorded as the hydrogen supply performance. In the initial stage, it is assumed that predetermined standard hydrogen supply amount data is stored as a hydrogen supply record.

  And it is judged whether it is necessary to change the amount of hydrogen production (S3). As a specific method, the determination is made based on whether or not the flow rate difference between the current flow rate of the currently input hydrogen and the previous flow rate of the previously input hydrogen exceeds a predetermined allowable range. If the flow rate difference is within the allowable range, the process branches to step S1 and repeats steps S1 to S3. If the flow rate difference is outside the allowable range, the process proceeds to the next step S4.

  In step S4, it is determined whether or not the current flow rate has decreased from the previous flow rate (S4). At this time, if the current flow rate is higher than the previous flow rate, the reformed gas from the multi-cylinder reformer 12 is increased to increase hydrogen by opening the control valves 26a and 33a in the production increase process. Is started (S5), and the process proceeds to step S1. In step S4, when the current flow rate is lower than the previous flow rate, after the production reduction process is executed (S6), the process proceeds to step S1.

  In this production reduction process, as shown in FIG. 4, the driving history stored in the storage means is read to predict the driving pattern for today (SB1). That is, the past hydrogen supply results are accumulated in the operation history, and data of the same day of the week closest to the same day of the same month as the current day is extracted from the operation history. And the change of the supply amount after the same time as the present time is read from this data, and it is set as today's prediction operation pattern.

  Based on the predicted operation pattern, a change in increase / decrease in the amount of hydrogen used after decreasing the amount of purified hydrogen is predicted, and whether or not preparation for production increase is necessary (SB2). The condition for determining whether or not preparation for increasing production is necessary is made based on whether or not the hydrogen supply amount is expected to increase more than a predetermined amount within a predetermined time from the start of the reduction of the purification amount.

  The predetermined time is determined based on the time until the amount of reformed gas produced recovers to 30% of the maximum produced amount when the multi-cylinder reformer 12 is stopped and the operation is resumed. Further, the specified amount is determined based on the adjustable range of the amount of reformed gas generated by the single multi-cylinder reformer 12 alone and the operating status of each multi-cylinder reformer 12.

  In this step (SB2), if it is determined that preparation for increased production is not necessary based on the prediction that the hydrogen supply will not increase more than the specified amount within a predetermined time after the reduction of the purification amount, fine adjustment according to the hydrogen supply is made. While performing, one of the multiple cylinder reformers 12 is stopped (SB3), and the process returns to the main routine.

  Specifically, the control valves 26a and 33a connected to the multiple cylinder reformer 12 to be stopped are fully closed and stopped. At this time, the amount of generated hydrogen is increased by adjusting the opening degree of the control valves 26a and 33a connected to the remaining multi-cylinder reformer 12 so that the generated amount of hydrogen does not drop below the required amount. Make fine adjustments to the amount.

  Further, in step (SB2), when it is determined that preparation for increased production is necessary from the prediction that the hydrogen supply amount will increase by more than the specified amount within a predetermined time after the reduction of the purification amount, the operating multi-cylinder reformer 12 is in operation. Does not stop, suppresses the amount of reformed gas produced by the multiple cylinder reformer 12 (SB4), and returns to the main routine.

  Specifically, the amount of reformed gas generated is suppressed by adjusting the throttle amount of the control valves 26a and 33a connected to each of the multiple cylinder reformers 12, and the amount of hydrogen purified by the hydrogen purifier 16 is set to the target value. Decrease to. At this time, the production amount may be suppressed with respect to all the multi-cylinder reformers 12 in operation, or may be performed with respect to any of the multi-cylinder reformers 12, and the production reduction amount An appropriate method according to the method is used.

  Next, the operation and effect of this embodiment will be described.

  As described above in detail, in the hydrogen production apparatus 10 according to the present embodiment, the multi-cylinder reformer 12 is used as the reformer. Therefore, the overall size can be reduced.

  Further, in the multi-cylinder reformer 12, since the preheating unit, the reforming unit, the CO conversion unit, and the CO removing unit are integrated, the number of pipes is reduced and the systemization of the hydrogen production apparatus 10 is facilitated.

  Further, as the reformer, as described above, the multi-cylinder reformer 12 with less piping and easy cost reduction is used, so that the cost of the hydrogen production apparatus 10 can be reduced.

  In addition, since a plurality of the multi-tubular reformers 12 are provided in parallel with the hydrogen purifier 16, for example, when the required hydrogen production amount changes corresponding to the specifications (rated output) of the fuel cell system, By adjusting the number of installed tubular reformers 12, it is possible to easily cope with a required change in the amount of hydrogen production. Thereby, the necessity of design change, such as enlargement of the multi-cylinder reformer 12, can be eliminated.

  Further, for example, when it is desired to change the amount of hydrogen supplied to the fuel cell in response to a load variation of the fuel cell, the number of operations of the multi-cylinder reformer 12 may be adjusted. The conditions can be kept constant, and the composition variation of the reformed gas can be suppressed.

  In addition, the system can be continuously operated during maintenance and failure of the multiple cylinder reformer 12 by performing an operation such that a plurality of the multiple cylinder reformers 12 are maintained one by one with the rotation number. .

  Then, when reducing the amount of hydrogen to be supplied and reducing the amount of hydrogen produced, if it is necessary to prepare for increased production from the prediction of changes in the amount of hydrogen supplied after the reduction in production, the multi-cylinder reformer 12 is stopped. Without reducing the amount of reformed gas produced.

  Here, once the multi-cylinder reformer 12 is stopped, it takes time for the reformed catalyst layer 36 to reach a predetermined temperature and the amount of reformed gas to be recovered to a normal level even if the operation is resumed. Therefore, by suppressing the amount of reformed gas generated without stopping the multiple cylinder reformer 12, the followability at the start of production increase can be improved.

  On the other hand, if the preparation for increasing production is unnecessary from the prediction of the change in the hydrogen supply amount after the decrease in the production amount, one of the multiple cylinder reformers 12 is stopped to reduce the production amount. For this reason, the operating multi-cylinder reformer 12 can be maintained in a state in which the hydrogen production efficiency is high, and the overall efficiency reduction in the hydrogen production apparatus 10 can be suppressed.

  As a result, it is possible to achieve both improvement in hydrogen production efficiency when the amount of hydrogen production is reduced and improvement in followability when production is increased after the reduction.

At this time, since the multiple cylinder reformer 12 is used in the hydrogen production apparatus 10, it is possible to shorten the time taken to start and stop each of the multiple cylinder reformers 12.
More specifically, each of the catalysts 36, 45, 47 has a smaller heat capacity than the other reformers separately provided, and the single-burner 26 is used for all the catalysts 36. , 45 and 47, the time taken to start and stop the individual multi-cylinder reformer 12 can be shortened.
Further, in the hydrogen production apparatus 10, since the unreformed gas generated from the multi-cylinder reformer 12 during startup can be removed by the hydrogen purifier 16, an unreformed gas bypass flow path for startup is unnecessary. Cost reduction can be achieved.

  Further, it is determined whether or not preparation for increasing production is necessary based on whether or not an increase in the hydrogen supply amount is predicted within a predetermined time after the purification amount is decreased. For this reason, when an increase in production is expected immediately after a decrease in production volume, the amount of reformed gas produced by the multi-cylinder reformer 12 can be suppressed, and the followability during production increase can be improved.

  On the other hand, when it is predicted that production will not increase for a while after the production volume decreases, any of the multi-cylinder reformers 12 is stopped to reduce the production volume, so that a reduction in hydrogen production efficiency can be suppressed.

  Next, a modification of this embodiment will be described.

  In the above embodiment, city gas is used as an example of a hydrocarbon raw material, but a hydrocarbon raw material other than city gas, for example, a gas mainly composed of hydrocarbon such as propane, or a hydrocarbon-based liquid is used. May be.

  Moreover, when hydrocarbon raw materials other than city gas are used, the multiple cylinder type | mold reformer 12 may be changed into structures other than the above (structure suitable for the hydrocarbon raw material to be used).

  Moreover, in the said embodiment, although the PSA apparatus is used as the hydrogen purifier 16, for example, the hydrogen purification apparatus which has a hydrogen separation membrane etc. may be used.

  Moreover, although the hydrogen production apparatus 10 which concerns on this embodiment is used suitably for a fuel cell system, you may be used for apparatuses and systems other than a fuel cell system. For example, an industrial heat treatment furnace or the like may be used as the hydrogen production apparatus 10 that supplies hydrogen consumed as a reducing gas for maintaining a reducing atmosphere inside the furnace.

  Further, in the present embodiment, the multiple cylinder reformer 12 is stopped or the multiple cylinder reformer is stopped based on whether or not the hydrogen supply amount increases by a predetermined amount or more within a predetermined time after the purification amount is reduced. Although it was selected whether to suppress the generation amount by 12, it is not limited to this. For example, when the production rate is gradually increased or decreased after the refining amount is reduced, when the increase is continued, or when the production rate is rapidly increased, the multiple cylinder reformer 12 is stopped based on the change in the hydrogen supply amount. Alternatively, the generation amount may be selectively suppressed.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and other various modifications can be made without departing from the spirit of the present invention. It is.

DESCRIPTION OF SYMBOLS 10 ... Hydrogen production apparatus, 12 ... Multiple cylinder type reformer, 14 ... Compressor, 16 ... Hydrogen purifier, 16 ... Flowmeter, 21-24 ... Cylindrical wall, 25 ... Combustion chamber, 26 ... Burner, 27 ... Combustion exhaust gas flow path, 28 ... gas discharge pipe, 31 ... first flow path, 32 ... preheating flow path, 33 ... raw material supply pipe, 34 ... reforming water supply pipe, 35 ... spiral member, 36 ... reforming catalyst layer, 42 2nd flow path, 43 ... reformed gas flow path, 44 ... reformed gas discharge pipe, 45 ... CO shift catalyst layer, 46 ... oxidant gas supply pipe, 47 ... CO removal catalyst layer, 60 ... control unit (judgment) Means, suppression means, stop means)

Claims (3)

A plurality of multi-cylinder reformers connected in parallel to each other and reforming a hydrocarbon raw material to generate reformed gas mainly containing hydrogen;
A hydrogen purifier that is connected to the plurality of multi-cylinder reformers and purifies hydrogen by separating the reformed gas generated in the plurality of multi-cylinder reformers into impurities and hydrogen;
A hydrogen production apparatus comprising: When reducing the amount of hydrogen purified with the decrease in the amount of hydrogen supplied to the downstream side of the hydrogen purifier, changes in the amount of hydrogen supplied after the reduction in the amount of purification are predicted from the past hydrogen supply results. A determination means for determining whether or not preparation for an increase in production is necessary,
Suppression means for suppressing the amount of reformed gas produced by the multiple-cylinder reformer when the judging means judges that preparation for increased production is necessary;
Stop means for stopping a part of the multiple cylindrical reformers when the judgment means judges that preparation for increased production is unnecessary;
The hydrogen production apparatus according to claim 1, further comprising:   3. The hydrogen production apparatus according to claim 2, wherein the determining means determines whether or not preparation for increasing production is necessary based on whether or not an increase in the hydrogen supply amount is predicted within a predetermined time from the start of the decrease in the purification amount.