JP2019172552A - Hydrogen production equipment - Google Patents

Abstract

To provide hydrogen production equipment in which a reforming part can favorably perform a reform process while the release of off-gas stored in an off-gas tank to the outside is avoided.SOLUTION: The hydrogen production equipment comprises: a reforming part A which includes a reform reaction part 2 reforming raw material gas G into a reformed gas K and a combustion part 3 heating the reform reaction part 2; a pressure swing absorption part B which includes an absorption column 1 absorbing, by an absorbent, components to be absorbed from the reformed gas K to generate production gas H; an off-gas tank T which recovers an off-gas exhausted from the pressure swing absorption part B; an off-gas supply channel 4 which supplies the off-gas stored in the off-gas tank T to the combustion part 3; and a control part M which, when the maximum value of the off-gas stored amount is larger than a preset optimum upper limit value, changes the operation state of the reforming part A to an off-gas consumption amount-increased operation state for increasing the amount of off-gas consumed in the combustion part 3 with the processed amount of the raw material gas kept constant.SELECTED DRAWING: Figure 1

Description

  The present invention provides a water vapor mixing section for mixing water vapor so that the ratio of the number of moles of water vapor mixed with a raw material gas that is a hydrocarbon gas to the number of moles of carbon in the raw material gas is a target ratio, From the reforming section, a reforming reaction section having a reforming reaction section for reforming to a reformed gas having a large amount of hydrogen components by steam reforming, and a combustion section for heating the reforming reaction section to a reforming reaction temperature. A pressure fluctuation adsorption unit having an adsorption tower that adsorbs an adsorption target component other than a hydrogen component from the reformed gas to an adsorbent to produce a product gas, and an off gas that collects off-gas discharged from the pressure fluctuation adsorption unit The present invention relates to a hydrogen production apparatus provided with a gas tank, an offgas supply path for supplying the offgas stored in the offgas tank to the combustion unit, and a control unit for controlling the operation of the reforming unit and the pressure fluctuation adsorption unit .

  Such a hydrogen production apparatus reforms a raw material gas, which is a hydrocarbon gas such as natural gas or naphtha, into a reformed gas having a large amount of hydrogen components by a steam reforming process using a reforming unit, A product gas having a high hydrogen concentration is produced by adsorbing an adsorbing target component on an adsorbent from a reformed gas containing an adsorbing target component other than the component and the hydrogen component.

  Since the off-gas discharged from the pressure fluctuation adsorbing part contains combustible components, the off-gas discharged from the pressure fluctuation adsorbing part is collected in the off-gas tank, and the off-gas stored in the off-gas tank is changed to the reforming part. Supplying to a combustion part which heats a reforming reaction part and making it burn is performed (for example, refer to patent documents 1).

JP 2004-299995 A

  In the hydrogen production apparatus, the amount of off-gas collected and stored in the off-gas tank becomes excessive, and there is a case where the off-gas stored in the off-gas tank is wasted to the outside, and improvement has been desired.

That is, for example, when the production amount of the product gas is reduced, the amount of off gas stored in the off gas tank is excessive, and the off gas stored in the off gas tank may be discharged to the outside.
In other words, the production volume of product gas will fluctuate with changes in the consumption volume of the consumption section that consumes product gas. When reducing the production volume of product gas, supply it to the reforming section. This reduces the amount of source gas supplied.
When the supply amount of the raw material gas supplied to the reforming unit is decreased, the off-gas consumed in the combustion unit to heat the reforming reaction unit of the reforming unit to the reforming reaction temperature according to the decrease. The amount of will decrease.

  However, immediately after the supply amount of the raw material gas supplied to the reforming unit is decreased, a large amount of the reformed gas before the decrease of the supply amount of the raw material gas is supplied to the pressure fluctuation adsorption unit. As a result, a large amount of off-gas is discharged from the pressure fluctuation adsorbing unit, and as a result, the amount of off-gas stored in the off-gas tank may be excessive, and in such a case, the off-gas tank The stored off-gas has been discharged to the outside.

  The present invention has been made in view of the above circumstances, and the object thereof is to allow the reforming process of the reforming section to be performed satisfactorily while avoiding the release of the offgas stored in the offgas tank to the outside. It is in the point which provides the hydrogen production apparatus which can be performed.

The hydrogen production apparatus of the present invention includes a water vapor mixing unit that mixes water vapor so that the ratio of the number of moles of water vapor mixed with the raw material gas that is a hydrocarbon-based gas to the number of moles of carbon in the raw material gas is a target ratio. A reforming section comprising a reforming reaction section for reforming the raw material gas into a reformed gas having a large amount of hydrogen component by steam reforming, and a combustion section for heating the reforming reaction section to a reforming reaction temperature; A pressure fluctuation adsorption part having an adsorption tower for adsorbing an adsorbent component other than a hydrogen component from the reformed gas from the reforming part to produce a product gas, and off-gas discharged from the pressure fluctuation adsorption part Provided with an off-gas tank that collects the off-gas, an off-gas supply path that supplies the off-gas stored in the off-gas tank to the combustion unit, and a control unit that controls the operation of the reforming unit and the pressure fluctuation adsorption unit Because Characteristic configuration of,
An off-gas amount detection unit for detecting an off-gas storage amount of the off-gas stored in the off-gas tank is provided;
In the case where the maximum value of the off-gas storage amount that repeatedly increases and decreases with the operation of the pressure fluctuation adsorption unit is less than or equal to a set appropriate upper limit value, the control unit operates the reforming unit in a reference operation state, and When the maximum value is larger than the set appropriate upper limit value, the operation state of the reforming unit is consumed in the combustion unit while maintaining the processing amount of the source gas at the same processing amount. The off gas consumption amount is changed to an off gas consumption increasing operation state in which the off gas consumption amount is increased from the consumption amount in the reference operation state.

That is, the amount of off-gas stored in the off-gas tank repeatedly increases and decreases with the operation of the pressure fluctuation adsorption unit, and the maximum value of the off-gas storage stored in the off-gas tank is set appropriately. In the case of the upper limit value or less, the control unit operates the reforming unit in the reference operation state.
And when the maximum value of the off gas storage amount stored in the off gas tank is larger than the set upper limit value, the control unit maintains the operation amount of the reforming unit at the same processing amount of the raw material gas. In this state, the consumption amount of the off gas consumed in the combustion unit is changed to the off gas consumption increasing operation state in which the amount consumed in the reference operation state is increased.

  As described above, when the maximum value of the off gas storage amount stored in the off gas tank is larger than the set upper limit value, the amount of off gas consumed in the combustion unit of the reforming unit is increased. Since the consumption of the stored off gas also increases, it is possible to avoid releasing the off gas stored in the off gas tank to the outside.

  In the off gas consumption increasing operation state, for example, the reforming reaction section is heated to a high temperature at which the reforming reaction can proceed more easily than in the reference operation state, and the raw material gas is improved to the reformed gas by the steam reforming process. The reforming process of the reforming section can be performed satisfactorily such as reforming.

  In short, according to the characteristic configuration of the hydrogen production apparatus of the present invention, it is possible to satisfactorily perform the reforming process of the reforming section while avoiding the release of the offgas stored in the offgas tank to the outside.

  In a further characteristic configuration of the hydrogen production apparatus according to the present invention, the control unit increases the reforming reaction temperature in the off-gas consumption increasing operation state, which is higher in off-gas consumption than the reference target temperature in the reference operation state. The point is to change to the target temperature.

  That is, in the off gas consumption increasing operation state, the reforming reaction temperature in the reforming reaction section is set to a high off gas consumption increasing target temperature higher than the reference target temperature in the reference operating state, and the reforming reaction is proceeded to a high temperature. By heating the reforming reaction section, the raw material gas can be satisfactorily reformed into the reformed gas by the steam reforming process.

  In other words, if the reforming reaction temperature in the reforming reaction section is set to a high temperature, the reforming reaction section can be easily advanced, but the reforming reaction section is heated to a high temperature using a gas other than off-gas. In order to avoid heating, the reforming reaction temperature is set to a reference target temperature that can be heated by consumption of off-gas in the reference operation state.

  When the maximum off-gas storage amount of the off-gas stored in the off-gas tank exceeds the set upper limit value, excess off-gas is consumed by the reforming reaction section at a higher off-gas consumption than the reference target temperature. By using it for heating to the amount increase target temperature, the steam reforming process in the reforming section can be performed satisfactorily.

  In short, according to the further characteristic configuration of the hydrogen production apparatus of the present invention, surplus off-gas is used to heat the reforming reaction section to the off-gas consumption increase target temperature, thereby in the reforming section. The steam reforming process can be performed satisfactorily.

  According to a further characteristic configuration of the hydrogen production apparatus of the present invention, the control unit sets the target ratio to an offgas consumption increase ratio larger than the reference operation ratio in the reference operation state in the offgas consumption increase operation state. There is a point to change to.

  That is, in the off gas consumption increasing operation state, the off gas consumption in which the target ratio, which is the ratio of the number of moles of water vapor supplied to the source gas to the number of moles of carbon in the source gas, is larger than the reference operation ratio in the reference operation state. As a result of changing to the ratio for increasing the amount, the consumption of off-gas consumed in the combustion section increases in order to heat the reforming reaction section to the reforming reaction temperature.

That is, the target ratio (S / C), which is the ratio of the number of moles of water vapor supplied to the raw material gas to the number of moles of carbon in the raw material gas, is a theoretical value for subjecting the raw material gas to steam reforming treatment. If the value is also set to a large value, the reforming reaction in the reforming reaction section can be facilitated.
However, as the target ratio (S / C) is set to a larger value, the consumption of off-gas consumed in the combustion section increases because the reforming reaction section is heated to the reforming reaction temperature. In order to avoid heating the reforming reaction section using a gas other than off gas, the target ratio (S / C) in the reference operation state is set to a reference operation ratio that is slightly larger than the theoretical value. Has been.

  And when the maximum value of the off-gas storage amount of the off-gas stored in the off-gas tank becomes larger than the set upper limit value, it is surplus in order to heat the reforming reaction section to the reforming reaction temperature. In view of the fact that a large amount of off gas can be used, the steam reforming process in the reforming section is performed while consuming excess off gas by setting the target ratio (S / C) to the off gas consumption increasing ratio. It can be done well.

  In short, according to the further characteristic configuration of the hydrogen production apparatus of the present invention, the steam reforming process in the reforming section while the surplus offgas is consumed while the target ratio is set to the offgas consumption increasing ratio. Can be performed satisfactorily.

  A further characteristic configuration of the hydrogen production apparatus according to the present invention is that when the maximum value of the off-gas storage amount that the control unit repeatedly increases or decreases with the operation of the pressure fluctuation adsorption unit is equal to or less than the set upper limit value. Is that the operation state of the reforming unit is returned to the reference operation state.

  In other words, after the reforming unit is operated in the off gas consumption increasing operation state, and the maximum value of the off gas storage amount that is repeatedly increased or decreased is equal to or less than the set upper limit value, the operation state of the reforming unit is the reference operation. It will be returned to the state.

  As described above, when the maximum value of the off gas storage amount is equal to or less than the set upper limit value, the operation state of the reforming unit is returned to the reference operation state. Therefore, the off gas stored in the off gas tank is removed. It is possible to suppress consumption more than necessary.

  In short, according to the further characteristic configuration of the hydrogen production apparatus of the present invention, it is possible to suppress consumption of the offgas stored in the offgas tank more than necessary.

  A further characteristic configuration of the hydrogen production apparatus according to the present invention is that the off-gas amount detection unit is configured to detect an internal pressure of the off-gas tank.

  That is, since the off gas amount detection unit detects the internal pressure of the off gas tank as the off gas storage amount of the off gas stored in the off gas tank, the off gas storage amount can be detected with a simple configuration.

  That is, for example, by integrating the flow of off-gas collected in the off-gas tank to obtain the integrated amount of off-gas collected in the off-gas tank, integrating the flow of off-gas discharged from the off-gas tank and discharging from the off-gas tank It is conceivable to obtain the accumulated amount of offgas discharged and subtract the accumulated exhaust amount from the collected accumulated amount to detect the offgas stored amount, but in this case, the configuration for detecting the offgas stored amount becomes complicated.

  On the other hand, since the internal pressure of the off gas tank is detected as the off gas storage amount, the off gas storage amount can be detected with a simple configuration.

  In short, according to the further characteristic configuration of the hydrogen production apparatus of the present invention, the off-gas storage amount can be detected with a simple configuration.

Overall view showing the hydrogen production system Schematic showing pressure fluctuation adsorption part The figure which shows the operation cycle of the pressure fluctuation adsorption part Explanatory drawing showing the operating state of the pressure fluctuation adsorption unit Explanatory drawing showing the operating state of the pressure fluctuation adsorption unit Explanatory drawing showing the operating state of the pressure fluctuation adsorption unit

Embodiment
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Overall configuration of hydrogen production equipment)
As shown in FIG. 1, the hydrogen production apparatus includes a reforming section A that reforms a raw material gas G that is a hydrocarbon gas such as natural gas or naphtha into a reformed gas having a large amount of hydrogen components, and the reforming section. A pressure fluctuation adsorbing portion B having an adsorption tower 1 that generates a product gas H by adsorbing an adsorbent component other than a hydrogen component from the reformed gas from A and discharged from the pressure fluctuation adsorbing portion B. An off-gas tank T that collects off-gas and a control unit M that controls the operation of the reforming unit A and the pressure fluctuation adsorption unit B are provided.

The reforming section A includes a steam mixing section J for mixing steam such that the ratio of the number of moles of steam mixed with the source gas G to the number of moles of carbon in the source gas is a target ratio (S / C), A reforming reaction tube 2 as a reforming reaction unit that reforms the gas G into a reformed gas having a large amount of hydrogen components by steam reforming, and a combustion unit that heats the reforming reaction tube 2 to a reforming reaction temperature. The burner 3 is provided.
An off gas supply path 4 for supplying off gas stored in the off gas tank T to the burner 3 is provided, and an air supply path 5 for supplying combustion air to the burner 3 is provided.

A raw material gas supply line 7 for conveying the raw material gas G to the desulfurizer 6 is provided, and a mixing unit conveying line 9 for conveying the raw material gas G desulfurized by the desulfurizer 6 to the water mixing unit 8 is provided.
The water mixing unit 8 is configured to supply water conveyed through the water supply line 10 and mix it with the raw material gas G after the desulfurization treatment.

An evaporation transport line 12 for transporting the raw material gas G mixed with water in the water mixing unit 8 toward the evaporating heat exchange unit 11 is provided, and the water mixed with the raw material gas G is used for the evaporating heat exchange unit 11. It is comprised so that it may be heated and steamed.
Incidentally, in the present embodiment, the water vapor mixing section J includes the water mixing section 8 and the evaporation heat exchange section 11 as main parts.

Then, the raw material gas G heated so as to be in a state containing water vapor (a state where water vapor is mixed) in the evaporating heat exchange unit 11 is conveyed to the reforming reaction tube 2 through the reaction tube conveyance line 13. The reforming gas K having a large amount of hydrogen component is reformed by the steam reforming process.
In other words, the reforming reaction tube 2 is filled with the reforming catalyst and heated to the reforming reaction temperature (for example, 750 ° C.) by the burner 3 as described above, so that the hydrogen is formed by the steam reforming process. It is comprised so that it may modify | reform to reformed gas with many components.

  By the way, in the present embodiment, the combustion gas of the burner 3 flows toward the heat exchanger 11 for evaporation after heating the reforming reaction tube 2 and heats the heat exchanger 11 for evaporation. It is configured to be discharged through the passage 14.

A transformer transport line 16 for transporting the reformed gas K from the reforming reaction tube 2 to the CO converter 15 is provided, and carbon monoxide contained in the reformed gas K is converted into carbon dioxide by the CO converter 15. It is configured to be transformed.
Then, the reformed gas K that has been subjected to the transformation process in the CO transformer 15 is supplied to the pressure fluctuation adsorption section B through the reformed gas supply line 17.
The reformed gas supply line 17 includes a water separator 18 including a water cooler 18a and a steam / water separator 18b, and is configured to remove excess moisture from the reformed gas K.

(Details of pressure fluctuation adsorption section)
The pressure fluctuation adsorption unit B of the present embodiment includes a first adsorption tower 1A, a second adsorption tower 1B, and a third adsorption tower 1C as the adsorption tower 1.
As shown in FIG. 2, the lower part of each of the three adsorption towers 1 has a first supply branch passage 21 a and a second supply valve 20 b provided with a first supply valve 20 a with respect to the reformed gas supply line 17. The second supply branch passage 21b and the third supply branch passage 21c provided with the third supply valve 20c are connected.

Each adsorption tower 1 is filled with an adsorbent that adsorbs a component to be adsorbed other than the hydrogen component from the reformed gas K.
The adsorption target components other than the hydrogen component are carbon dioxide, carbon monoxide, methane, nitrogen and the like, and carbon monoxide and methane are combustible components.

  Further, the upper part of each of the three adsorption towers 1 is connected to the product gas discharge line 22 with a first discharge branch path 22a having a first discharge valve 23a and a second discharge valve having a second discharge valve 23b. The branch path 22b is connected via a third discharge branch path 22c having a third discharge valve 23c.

Further, the upper part of each of the three adsorption towers 1 is connected to the pressure equalizing line 24 by a first pressure equalizing branch path 24a provided with a first pressure equalizing valve 25a and a second pressure equalizing branch provided with a second pressure equalizing valve 25b. The passage 24b is connected via a third pressure equalizing branch 24c provided with a third pressure equalizing valve 25c.
A cleaning line 26 is provided for flowing the product gas H flowing through the product gas discharge line 22 to the pressure equalizing line 24, and a cleaning valve 27 is provided in the cleaning line 26.

  Furthermore, the lower part of each of the three adsorption towers 1 has a first off-gas branch path 28a having a first off-gas valve 29a and a second off-gas branch having a second off-gas valve 29b with respect to the off-gas discharge line 28. The off gas discharge line 28 is connected to the off gas tank T through the passage 28 b and the third off gas branch passage 28 c provided with the third off gas valve 29 c.

  As shown in FIG. 3, the pressure fluctuation adsorption unit B is controlled by the operation of the control unit M so that the adsorption process, the pressure equalization (discharge) process, the pressure reduction process, the washing process, the pressure equalization ( It is configured to generate a product gas H containing high-purity hydrogen gas from the reformed gas K by repeatedly performing an operation cycle including an acceptance process and a pressure-increasing process in a state where the operation phases are different. .

  That is, the first unit period in which the first adsorption tower 1A performs the adsorption process, the second unit period in which the second adsorption tower 1B performs the adsorption process, and the third unit period in which the third adsorption tower 1C performs the adsorption process are repeatedly executed. It is configured as follows.

  In addition, in the first unit cycle in which the first adsorption tower 1A performs the adsorption process, the first supply valve 20a and the first discharge valve 23a are opened, and the adsorption target component contained in the reformed gas K is removed. An adsorption process for adsorption is performed (see FIGS. 4 to 6), and the product gas H is discharged from the first adsorption tower 1 </ b> A to the product gas discharge line 22.

At the beginning of the first unit period, the second pressure equalizing valve 25b of the second adsorption tower 1B and the third pressure equalizing valve 25c of the third adsorption tower 1C are opened, and the internal gas of the third adsorption tower 1C is second adsorbed. A pressure equalizing step for supplying to the tower 1B is performed (see FIG. 4).
This pressure equalization step corresponds to a pressure equalization (discharge) step in the third adsorption tower 1C, and corresponds to a pressure equalization (acceptance) step in the second adsorption tower 1B.

  In the second adsorption tower 1B, when the pressure equalizing step is completed, the second pressure equalizing valve 25b is closed, and the second exhaust valve 23b is opened, so that the product gas H discharged from the first adsorption tower 1A is discharged. The boosting step to be introduced is executed until the first unit period ends (see FIGS. 5 and 6).

  In the third adsorption tower 1C, when the pressure equalizing step is completed, the third pressure equalizing valve 25c is closed and the third off-gas valve 29c is opened, so that the internal gas of the third adsorption tower 1C is removed from the off-gas discharge line 28. (See FIG. 5), the third pressure equalizing valve 25c and the cleaning valve 27 are then opened while the third off-gas valve 29c is open, and the product gas H is supplied from the cleaning line 26. A cleaning process is performed (see FIG. 6).

Further, the offgas discharged to the offgas discharge line 28 in the decompression process and the cleaning process is collected in the offgas tank T and then supplied to the burner 3 of the reforming section A through the offgas supply path 4.
The off gas contains carbon monoxide, methane, and hydrogen as combustible components.

The off-gas storage amount stored in the off-gas tank T is repeatedly increased and decreased with the operation of the pressure fluctuation adsorption unit B.
That is, in each of the first unit period, the second unit period, and the third unit period, the off-gas storage amount rapidly increases when the decompression process is started, and the off-gas storage amount also increases when the cleaning process is performed thereafter. When the pressure equalization step is performed, the off-gas storage amount repeatedly increases and decreases while the off-gas storage amount gradually decreases.

Incidentally, a pressure sensor PS that detects the internal pressure of the offgas tank T is provided as an offgas amount detection unit that detects the amount of offgas stored in the offgas tank T.
Further, as shown in FIG. 1, a replenishment line 19 is provided for supplying the reformed gas K from the reformed gas supply line 17 to the offgas tank T when the amount of offgas stored in the offgas tank T is insufficient. A supply valve 19A for opening and closing the supply line 19 is provided.
When the pressure sensor PS detects that the amount of off-gas stored in the off-gas tank T is insufficient, the supply valve 19A is opened, and the amount of off-gas stored in the off-gas tank T becomes the set reference amount. Until the pressure sensor PS detects that the reformed gas K is supplied to the off-gas tank T.

In the first unit cycle in which the first adsorption tower 1A performs the adsorption process, as described above, the pressure equalization (acceptance) process and the pressure increase process are sequentially executed for the second adsorption tower 1B, and the third adsorption tower 1C As for, a pressure equalization (discharge) step, a pressure reduction step, and a cleaning step are sequentially executed.
The second unit period in which the second adsorption tower 1B performs the adsorption process and the third unit period in which the third adsorption tower 1C performs the adsorption process are the same as the first unit period in which the first adsorption tower 1A performs the adsorption process. In the present embodiment, detailed description of the second unit period and the third unit period is omitted.

(Operation control of reforming section)
The source gas supply line 7 is provided with a source gas supply unit 30 that supplies the source gas G and allows the supply amount to be adjusted, and a source gas sensor 31 that detects the supply amount of the source gas G.
Then, based on the instruction information indicating the target production amount of the product gas H, the control unit M is to supply the raw material gas G of the target raw material gas supply amount necessary for producing the target production gas amount of the product gas H. The operation of the source gas supply unit 30 is controlled.
That is, the operation of the raw material gas supply unit 30 is controlled such that the supply amount of the raw material gas G detected by the raw material gas sensor 31 becomes the target raw material gas supply amount.

  Incidentally, in the present embodiment, the raw material gas supply unit 30 supplies the raw material gas G with the compressor 30a and the flow rate at which a part of the raw material gas G supplied by the compressor 30a is returned to the upstream side of the compressor 30a. It is comprised in the form provided with the control valve 30b.

The water supply line 10 supplies water treated by the water treatment unit 32 to pure water to the water mixing unit 8. The water supply line 10 includes a water supply pump 33 for supplying water, and a water supply. A water flow rate sensor 34 that detects the flow rate of water supplied through the line 10 and a water flow rate adjustment valve 35 that adjusts the water supply amount are provided.
The water supply pump 33 is equipped with a pressure control valve 33a for controlling the water supply pressure to a set pressure.

Then, the control unit M sets the target ratio (S / C), which is the ratio of the number of moles of water vapor supplied to the source gas G to the number of moles of carbon in the source gas G, as a reference operation ratio (for example, 3.0), the operation of the water flow rate adjustment valve 35 is controlled.
That is, in a state where the raw material gas G is supplied at the target raw material supply amount, the target water supply amount for setting the target ratio (S / C) to the reference operation ratio in the reference operation state (for example, 3.0) is set. Thus, the operation of the water flow rate adjustment valve 35 is controlled so that the flow rate detected by the water flow rate sensor 34 becomes the target water supply amount.

A temperature sensor TS for detecting the internal temperature of the reforming reaction tube 2 is provided.
The off-gas supply path 4 is provided with an off-gas flow rate sensor 36 that detects the off-gas flow rate and an off-gas flow rate adjustment valve 37 that adjusts the off-gas flow rate.
The air supply path 5 is provided with a blower 38 that can supply air and adjust the supply amount, and an air flow rate sensor 39 that detects the amount of air flowing through the air supply path 5.

  Then, the control unit M sets the temperature sensor TS and the reference target so that the reforming reaction temperature of the reforming reaction tube 2 detected by the temperature sensor TS becomes the reference target temperature (for example, 750 ° C.) in the reference operation state. Based on the temperature, the target off-gas amount supplied to the burner 3 is obtained, and the operation of the off-gas flow rate control valve 37 is controlled so that the off-gas flow rate detected by the off-gas flow rate sensor 36 becomes the off-gas target amount. It is configured.

  Further, the control unit M obtains a target combustion air amount necessary for burning off-gas of the off-gas target amount, and the blower 38 so that the air amount detected by the air flow sensor 39 becomes the target air amount. It is comprised so that the action | operation of may be controlled.

(About off gas consumption increase operation)
In the case where the maximum value of the off-gas storage amount that repeatedly increases and decreases with the operation of the pressure fluctuation adsorption unit B is equal to or less than the set appropriate upper limit value, the control unit M operates the reforming unit A in the reference operation state, and When the maximum value of the off-gas storage amount is larger than the set upper limit value, the operation state of the reforming unit A is consumed by the burner 3 while maintaining the processing amount of the raw material gas G at the same processing amount. The off gas consumption amount is changed to an off gas consumption increasing operation state in which the off gas consumption amount is increased from the amount consumed in the reference operation state.

  In addition, when the maximum value of the off-gas storage amount that repeatedly increases and decreases with the operation of the pressure fluctuation adsorption unit becomes equal to or less than the set upper limit value, the control unit M changes the operation state of the reforming unit A to the reference operation state. It is configured to return to

That is, in the present embodiment, as described above, the pressure sensor PS that detects the internal pressure of the offgas tank is provided as the offgas amount detection unit that detects the offgas storage amount stored in the offgas tank T.
Since the internal pressure of the off gas tank T increases and decreases with the increase and decrease of the off gas storage amount in each of the first unit period, the second unit period, and the third unit period, the internal pressure is stored in the off gas tank T. The amount of off gas stored is detected by the pressure sensor PS as the internal pressure of the off gas tank.

In any of the first unit period, the second unit period, and the third unit period, the maximum value of the internal pressure of the off-gas tank T detected by the pressure sensor PS is set corresponding to the set upper limit value. When the pressure is not more than the upper limit pressure, the control unit M operates the reforming unit A in the standard operation state.
The maximum value of the internal pressure of the offgas tank T detected by the pressure sensor PS in any one of the first unit period, the second unit period, and the third unit period is set corresponding to the set upper limit value. When the pressure exceeds the upper limit pressure, the control unit M keeps the operation state of the reforming unit A in a state in which the processing amount of the raw material gas G is maintained at the same processing amount, The consumption amount is changed to the off gas consumption increasing operation state in which the consumption amount is increased more than the amount consumed in the reference operation state.

  In addition, after changing to the off gas consumption increasing operation state, the internal pressure of the off gas tank T detected by the pressure sensor PS in any one of the first unit period, the second unit period, and the third unit period. When the maximum value is equal to or lower than the set upper limit pressure, the control unit M returns the operation state of the reforming unit A to the reference operation state.

In the present embodiment, the control unit M maintains the state in which the reforming reaction tube 2 is heated to the reference target temperature (for example, 750 ° C.) by the burner 3, while the number of moles of steam supplied to the source gas G is maintained. The target ratio (S / C), which is the ratio to the number of moles of carbon in the raw material gas, is greater in the off-gas consumption increasing operation state than the reference operation ratio in the reference operation state (for example, 3.0). It is configured to change to an increase ratio (for example, 3.1).
As a result, when the target ratio (S / C) is increased, the temperature of the reforming reaction tube 2 is raised to the reference target temperature (for example, 750 ° C.) as the reforming reaction temperature by heating the burner 3. The amount of off gas required increases, and the off gas consumption of the off gas tank T increases.

  Therefore, immediately after reducing the supply amount of the raw material gas G in order to reduce the production amount of the product gas H, the internal pressure of the off-gas tank T detected by the pressure sensor PS becomes higher than the set upper limit pressure. In this case, by changing to the off gas consumption increase operation state, the consumption of the off gas stored in the off gas tank T is increased, and the off gas stored in the off gas tank T is released to the outside. Off-gas can be consumed.

  If the internal pressure of the off gas tank T detected by the pressure sensor PS becomes equal to or lower than the set upper limit pressure after changing to the off gas consumption increasing operation state, the operation state of the reforming section A is set as the reference operation. By returning to the state and reducing the consumption of off-gas, it is possible to avoid a situation where the off-gas tank T is replenished with the reformed gas K.

[Another embodiment]
Next, although another embodiment is described, this another embodiment shows another embodiment of off gas consumption increase operation, and since other forms are the same as the above-mentioned embodiment, Only the different parts will be described.

  That is, in this other embodiment, the control unit M sets the target ratio (S / C), which is the ratio of the number of moles of water vapor supplied to the source gas G to the number of moles of carbon in the source gas G, as the reference operation ratio ( For example, in the state maintained at 3.0), the reforming reaction temperature for raising the temperature of the reforming reaction tube 2 by heating the burner 3 is set to the reference target temperature (for example, the reference operating temperature in the off gas consumption increasing operation state). , 750 ° C.) that is higher than the target temperature for increasing offgas consumption (for example, 752 ° C.).

  As a result, the reforming reaction temperature of the reforming reaction tube 2 that is heated by heating the burner 3 is higher than the reference target temperature (for example, 750 ° C.) in the reference operation state, and the off gas consumption increase target temperature (for example, 752). ), The amount of off-gas required to raise the reforming reaction tube 2 to the off-gas consumption increase target temperature (for example, 752 ° C.) by heating the burner 3 increases, and the off-gas tank The off gas consumption of T will increase.

  Therefore, immediately after reducing the supply amount of the raw material gas G in order to reduce the production amount of the product gas H, the internal pressure of the off-gas tank T detected by the pressure sensor PS becomes higher than the set upper limit pressure. In this case, by changing to the off gas consumption increase operation state, the consumption of the off gas stored in the off gas tank T is increased, and the off gas stored in the off gas tank T is released to the outside. Off-gas can be consumed.

  If the internal pressure of the off gas tank T detected by the pressure sensor PS becomes equal to or lower than the set upper limit pressure after changing to the off gas consumption increasing operation state, the operation state of the reforming section A is set as the reference operation. By returning to the state and reducing the consumption of off-gas, it is possible to avoid a situation where the off-gas tank T is replenished with the reformed gas K.

[Other alternative embodiments]
Next, other embodiments are listed.
(1) In the above embodiment, the pressure fluctuation adsorption part B is exemplified as having three adsorption towers 1, but the present invention has two or four or more adsorption towers 1 as the pressure fluctuation adsorption part B. The present invention can also be applied to the case where the configuration is provided with.

(2) In the above embodiment, the pressure fluctuation adsorbing part B is exemplified as one configured to perform the cleaning process. However, in the present invention, the pressure fluctuation adsorbing part B is replaced with a cleaning process by a vacuum pump. The present invention can also be applied to a case where a suction process for sucking the inside of the adsorption tower 1 is performed.

(3) In the said embodiment, after mixing the water vapor | steam with the raw material gas G, the case where it was comprised so that the mixed water might be evaporated in the heat exchange part 11 for evaporation was illustrated. However, the water vapor mixing section J may be configured and implemented in a form in which water vapor generated in advance is mixed with the raw material gas G.

(4) In the above embodiment, the case where the pressure sensor PS that detects the internal pressure of the offgas tank is provided as the offgas amount detection unit that detects the offgas storage amount stored in the offgas tank T is illustrated. The unit integrates the flow of off-gas collected in the off-gas tank T to obtain the accumulated amount of off-gas collected in the off-gas tank T, integrates the flow of off-gas discharged from the off-gas tank T, and turns off Alternatively, the integrated amount of off-gas discharged from the gas tank T may be obtained, and the off-gas storage amount may be detected by subtracting the integrated amount of exhaust from the integrated amount of recovery.

  Note that the configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in the other embodiments as long as no contradiction arises. The embodiment disclosed in this specification is an exemplification, and the embodiment of the present invention is not limited to this. The embodiment can be appropriately modified without departing from the object of the present invention.

DESCRIPTION OF SYMBOLS 1 Adsorption tower 2 Reforming reaction part 3 Combustion part 4 Off gas supply path A Reforming part B Pressure fluctuation adsorption part G Raw material gas H Product gas K Reformed gas M Control part PS Off gas amount detection part T Off gas tank

Claims (5)

A steam mixing section for mixing steam so that the ratio of the number of moles of steam mixed with the raw material gas, which is a hydrocarbon gas, to the number of moles of carbon in the raw material gas is a target ratio, and the raw material gas is steam reformed A reforming reaction section for reforming to a reformed gas having a large amount of hydrogen component, a reforming section having a combustion section for heating the reforming reaction section to a reforming reaction temperature, and the reforming from the reforming section A pressure fluctuation adsorption unit including an adsorption tower that adsorbs an adsorption target component other than a hydrogen component from gas to an adsorbent to generate a product gas; an offgas tank that collects offgas discharged from the pressure fluctuation adsorption unit; and A hydrogen production apparatus provided with an off-gas supply path for supplying the off-gas stored in an off-gas tank to the combustion unit, and a control unit for controlling the operation of the reforming unit and the pressure fluctuation adsorption unit,
An off-gas amount detection unit for detecting an off-gas storage amount of the off-gas stored in the off-gas tank is provided;
In the case where the maximum value of the off-gas storage amount that repeatedly increases and decreases with the operation of the pressure fluctuation adsorption unit is less than or equal to the set appropriate upper limit value, the control unit operates the reforming unit in a reference operation state, and When the maximum value is larger than the set appropriate upper limit value, the operation state of the reforming unit is consumed in the combustion unit while maintaining the processing amount of the source gas at the same processing amount. The hydrogen production apparatus is configured to change the off gas consumption to an off gas consumption increasing operation state in which the off gas consumption is increased from an amount consumed in the reference operation state.   2. The hydrogen production apparatus according to claim 1, wherein the control unit changes the reforming reaction temperature to an offgas consumption increase target temperature that is higher than a reference target temperature in the reference operation state in the offgas consumption increase operation state. .   2. The hydrogen production apparatus according to claim 1, wherein the control unit changes the target ratio to an offgas consumption increase ratio larger than a reference operation ratio in the reference operation state in the offgas consumption increase operation state.   When the maximum value of the off-gas storage amount that repeatedly increases or decreases with the operation of the pressure fluctuation adsorption unit is less than or equal to the set upper limit value, the control unit determines the operation state of the reforming unit as the reference The hydrogen production apparatus according to any one of claims 1 to 3, wherein the hydrogen production apparatus is configured to return to an operating state.   The hydrogen production apparatus according to any one of claims 1 to 4, wherein the off-gas amount detection unit is configured to detect an internal pressure of the off-gas tank.

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