JP2023019891A - Hydrogen production device and operation method of hydrogen production device - Google Patents

Abstract

To provide a hydrogen production device for reducing an amount of fuel consumption in an operation state other than normal operation, and an operation method of the hydrogen production device.SOLUTION: A hydrogen production device 100 comprises: a compressor 105; a desulfurizer 110; a reformer 120; a transformer 130; a liquid gas separator 140; and a hydrogen purification unit 150, in which, there is also provided hydrogen circulation operation piping L51 for circulating hydrogen to an inlet of the compressor 105, from piping L4 coupling the liquid gas separator 140 and the hydrogen purification unit 150, and in hydrogen circulation operation in standby operation time, the hydrogen is circulated through the hydrogen circulation operation piping L51 while supplying pure water PW or steam.SELECTED DRAWING: Figure 5

Description

TECHNICAL FIELD The present invention relates to a hydrogen production device and a method of operating a hydrogen production device.

Conventionally, a hydrogen production apparatus is known to supply a hydrocarbon gas such as natural gas or LPG as a raw material gas to a reformer together with steam, and react it with a reforming catalyst to produce a hydrogen-containing gas. (See Patent Documents 1 and 2, for example). A hydrogen production apparatus for industrial use generally consumes hydrogen continuously, so it is often operated continuously day and night. In addition, if it is operated continuously day and night, the efficiency will be high, and as a result, the unit cost of hydrogen can be reduced.

On the other hand, it is assumed that the hydrogen production equipment used in hydrogen stations that fill fuel cell vehicles with hydrogen will not operate at night, especially during the period when hydrogen stations become popular. It can be said that it is more economical to stop

Therefore, in the hydrogen production apparatuses disclosed in Patent Documents 1 and 2, only already produced hydrogen or hydrogen-rich gas is circulated during standby operation in which hydrogen is not produced.
In other hydrogen production equipment, the amount of raw material gas supplied is reduced to the minimum (idling operation), and the minimum amount of hydrogen produced is circulated or used as fuel for the combustion burner of the reformer. self-consumption by doing.

JP 2015-030655 A JP 2016-000675 A

However, as in the hydrogen production apparatuses disclosed in Patent Documents 1 and 2, there is a problem that the catalyst of the hydrogen production apparatus is over-reduced only by circulating hydrogen or hydrogen-rich gas during standby operation. In addition, there is a problem that it takes time to return from standby operation to normal operation. Furthermore, when hydrogen is self-consumed in idling operation, it is possible to quickly shift to normal operation and return from normal operation, but there is a problem that a relatively large amount of fuel is consumed even during idling operation. .

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a hydrogen production apparatus and a method of operating the hydrogen production apparatus that can reduce fuel consumption during standby operation.

A hydrogen production apparatus according to one aspect of the present invention includes a compressor, a desulfurizer, a reformer, a shift converter, a gas-liquid separator, and a hydrogen purification apparatus, A hydrogen circulation operation pipe for circulating hydrogen from a pipe connecting between the gas-liquid separator and the hydrogen purifier to the inlet side of the compressor, and in hydrogen circulation operation during standby operation, pure While supplying water or steam, the hydrogen is circulated through the hydrogen circulation operation pipe.

According to another aspect of the present invention, there is provided a hydrogen production apparatus operating method comprising a compressor, a desulfurizer, a reformer, a shift converter, a gas-liquid separator, and a hydrogen purification apparatus. A method for operating a device, further comprising a hydrogen circulation operation pipe for circulating hydrogen from a pipe connecting between the gas-liquid separator and the hydrogen refining device to an inlet side of the compressor, and performing standby operation. In the hydrogen circulation operation, the hydrogen is circulated through the hydrogen circulation operation pipe while supplying pure water or steam.

ADVANTAGE OF THE INVENTION According to this invention, the hydrogen production apparatus and the operating method of a hydrogen production apparatus which can reduce the fuel consumption in the operating states other than normal operation can be provided.

FIG. 1 is a system diagram showing an outline of a hydrogen production apparatus according to an embodiment of the present invention. FIG. 2 is a system diagram showing an operating procedure A in the operating method of the hydrogen production apparatus. FIG. 3 is a system diagram showing an operating procedure B in the operating method of the hydrogen production apparatus. FIG. 4 is a system diagram showing an operating procedure C in the operating method of the hydrogen production apparatus. FIG. 5 is a system diagram showing an operating procedure D in the operating method of the hydrogen production apparatus. FIG. 6 is a system diagram showing an operating procedure F in the operating method of the hydrogen production apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in the embodiment of this specification, the same code|symbol is attached|subjected to the same member through the whole.

First, the hydrogen production device 100 will be described. FIG. 1 is a system diagram showing an outline of a hydrogen production device 100 of an embodiment according to the present invention.

The hydrogen production device 100 includes a desulfurizer 110, a reformer 120, a shift converter 130, a gas-liquid separator 140, and a hydrogen purification device 150 as main devices. In FIG. 1, _G1 denotes raw material gas, _G2 reformed gas, _G3 exhaust gas, _G4 transformed gas, _G5 purified gas, and OG off gas.

The desulfurizer 110 removes sulfur components contained as odorants in hydrocarbon fuels such as city gas and LPG. Since the sulfur component poisons the reforming catalyst and conversion catalyst of the reformer 120 used in the subsequent process, the sulfur component contained in the source gas _G1 is removed in advance by the desulfurizer 110. .

Specifically, the desulfurizer 110 is a flow filled with a hydrodesulfurization catalyst composed of, for example, a Co—Mo-based or Ni—Mo-based hydrogenation catalyst and a ZnO-based desulfurization catalyst that adsorbs hydrogen sulfide. made up of roads. The desulfurizer 110 is supplied with the raw material gas _G1 and hydrogen to cause a hydrogenation (hereinafter referred to as "hydrogenation") reaction, convert the sulfur component into hydrogen sulfide, and incorporate the hydrogen sulfide into zinc oxide. Zinc sulfide is used and the sulfur component is removed. Reaction formulas of this hydrodesulfurization are as shown in the following reaction formulas (1) and (2).
CmHnS+ _H2 →CmHn+ _H2S (1)
H ₂ S + ZnO → H ₂ O + ZnS (2)

The desulfurizer 110 may perform desulfurization using a sulfur compound adsorbent that reacts at room temperature or high temperature instead of the hydrogenation reaction as in the present embodiment. Moreover, in the case of the source gas _G1 containing no sulfur component, the desulfurizer 110 is not necessary.

The reformer 120 adds steam (or pure water) to the raw material gas _G1 and brings it into contact with a reforming catalyst (hereinafter referred to as “catalyst”) described later at a high temperature (for example, 650° C. to 900° C.) to convert the raw material into The gas _G1 is reformed to produce a reformed gas _G2 such as hydrogen or carbon monoxide. Reaction formulas of this steam reforming are as shown in the following reaction formulas (3) and (4).
CmHn+ _mH2O →mCO+(m+n/2)H2 ( ₃ )
CO+3H ₂ ←→ CH ₄ +H ₂ O (4)

These steam reforming reactions are endothermic reactions. The mixed steam/carbon ratio should be about 3 times to avoid depositing carbon on the surface of the catalyst.

This reformer 120 is equipped with a catalytic reaction tube filled with a catalyst for steam reforming. A plurality of these catalyst reaction tubes are arranged and housed inside a reaction furnace (not shown).

Then, the reformer 120 supplies a part of the raw material gas _G1 and an offgas OG from a hydrogen refining device 150 described later as fuel gas to the combustion burner 126 together with air from the air blower 125 to cause a catalytic reaction in the reactor. Heat the tube.

The shift converter 130 reacts carbon monoxide in the reformed gas _G2 sent from the reformer 120 with water vapor to generate more hydrogen _H2 . The reaction formula for this CO conversion is as shown in the following reaction formula (5).
CO+H ₂ O ←→ CO ₂ +H ₂ (5)

In this shift converter 130, for example, Fe--Cr-based, Cu--Zn-based or Pt-based catalysts are used depending on the reaction temperature, eg, 200.degree. C. to 500.degree.

The gas-liquid separator 140 separates and removes condensed water from the reformed gas _G2 as waste water.

The hydrogen purifier 150 uses an adsorbent to adsorb gases other than hydrogen _H2 , such as carbon monoxide, carbon dioxide, methane, _and water vapor _. Generally, it is possible to make the hydrogen concentration up to about 99.999%. The offgas OG generated by the hydrogen purifier 150 may be used as fuel for heating the reformer 120 .

The hydrogen production apparatus 100 includes, for example, a compressor 105 that compresses the raw material gas _G1 and feeds it to the desulfurizer 110, in addition to the main apparatuses described above.

Furthermore, the hydrogen production device 100 is equipped with the following components.
(1) A raw material pipe _L1 connecting the raw material supply source 160 and the compressor 105 is provided with a raw material adjusting valve _V1 .
(2) The compressor 105 and the desulfurizer 110 are connected by a second pipe _L2 , and the desulfurizer 110 and the reformer 120 are connected by a third pipe _L3 . A gas discharge pipe _L7 for discharging the exhaust gas _G3 is connected to the reformer 120 .
(3) The extraction pipe _L4 connecting the gas-liquid separator 140 and the hydrogen purifier 150 is provided with an on-off valve _V4 .
(4) On the outlet side of the hydrogen purifier 150, a hydrogen take-out pipe _L5 for taking out the refined purification gas (hydrogen _H2 ) _G5 is provided. This hydrogen extraction pipe _L5 is equipped with a hydrogen control valve _V5 .
(5) A fuel pipe L11 for supplying the raw material gas _{G1 as} a fuel gas from the raw material supply source 160 to the combustion burner 126 is provided, and the fuel pipe _L11 is provided with a fuel control valve _V11 . there is
(6) An offgas pipe _L12 for supplying offgas OG from the hydrogen purifier 150 to the combustion burner 126 is provided, and this offgas pipe _L12 is provided with an offgas holder 190 and an offgas control valve _V12 . there is
(7) A pure water pipe L ₃₁ is connected from the pure water supply source 170 to the third pipe L ₃ , and the pure water pipe L ₃₁ is provided with a pure water regulating valve V ₃₁ . A heat exchanger (not shown) is provided in the pure water pipe _L31 to convert the supplied pure water into steam. Alternatively, steam may be directly supplied.
(8) The take-out pipe _L4 is provided with a vent pipe _L42 for discharging gas, and is equipped with a vent control valve _V42 for releasing the pressure in the take-out pipe _L4 .
(9) A hydrogen circulation operation pipe L ₅₁ that loops from the extraction pipe L ₄ to the raw material pipe L ₁ is provided, and this hydrogen circulation operation pipe L ₅₁ is provided with a circulation on-off valve V ₅₁ .
(10) The raw material pipe _L1 is provided with a hydrogenation pipe _L61 for adding hydrogen _H2 from the hydrogen supply source 180, and the hydrogenation pipe _L61 is equipped with a hydrogenation control valve _V61 . there is
(11 ₎ A pipe L ₆₂ is connected to the hydrogen extraction pipe L ₅ and the hydrogenation pipe L ₆₁ , and part of the purified hydrogen is supplied to the hydrogenation pipe L ₆₁ . An auxiliary on-off valve _V62 is provided.
(12) Between the connecting portion of the pipe L ₆₂ connected to the hydrogenation pipe L ₆₁ and the hydrogen supply source 180, a hydrogen introduction opening/closing valve V ₆₃ is provided.
In addition to the above, pipes are also connected, for example, between the reformer 120 and the transformer 130. Although not shown, bypass pipes for maintenance of various devices and on-off valves are also provided as appropriate. It is

With such a configuration, the hydrogen production apparatus 100 sends the raw material gas _G1 to the desulfurizer 110 through the compressor 105 to remove the sulfur component, and then converts the raw material gas _G1 after desulfurization into pure water PW (water vapor ) to the reformer 120 to generate a reformed gas G2 containing hydrogen _H2 , send the reformed gas _G2 to the shift converter 130, further generate hydrogen _H2 as a reformed _{gas G4} , A gas-liquid separator 140 separates the liquid from the modified gas _G4 , and a hydrogen refining device 150 adsorbs off-gases other than hydrogen _H2 as offgas OG to produce a large amount of hydrogen _H2 as the purified gas _G5 .

(Operating procedure A)
FIG. 2 is a system diagram showing an operating procedure A in the operating method of the hydrogen production device 100. As shown in FIG.
As shown in FIG. 2, this operating procedure A indicates a state during normal operation. In the operating procedure A, a portion of the hydrogen H ₂ of the purified gas G ₅ from the hydrogen purifier 150 is circulated through the hydrogenation pipe L ₆₁ and the like for the hydrogenation reaction of the desulfurizer 110 . 2 to 6, the open state of the on-off valve or the regulating valve Vn is shown in open state, and the solid state is shown in the closed state. Yes, solid indicates off state.

(Operating procedure B)
FIG. 3 is a system diagram showing an operating procedure B in the operating method of the hydrogen production device 100. As shown in FIG.
As shown in _{FIG .} 3, this operating procedure B shows a state in which the hydrogen production operation is shifted to the standby operation. is shut off, the take-out regulating valve _V5 is closed, and the production of hydrogen _H2 by the hydrogen production device 100 is stopped.

At this time, the compressor 105 and the hydrogen purifier 150 are also stopped. When the compressor 105 is stopped, the hydrogenation control valve _V61 is closed, and when the hydrogen purification device 150 is stopped, the on-off valve _V4 , the offgas control valve _V12 , and the circulation on-off valve _V62 are closed. state.

Then, as shown in FIG. 3, while continuing to supply the pure water PW from the pure water supply source 170, the amount of pure water PW supplied is reduced by adjusting the flow rate of the pure water control valve _V31 . Further, the supply of the raw material gas G ₁ from the raw material supply source 160 through the fuel pipe L ₁₁ is continued, and the combustion of the combustion burner 126 is continued. Then, the opening degree of the fuel control valve _V11 is adjusted so that the reforming temperature of the reformer 120 is maintained at a predetermined temperature (for example, 800° C. to 900° C.). Further, the reforming process gas of the reforming system pipes from the raw material pipe L ₁ to the extraction pipe L ₄ is discharged to the outside as the vent gas G ₆ from the vent control valve V ₄₂ .

In other words _, in this operating procedure _B , while maintaining the heating _of the reformer ₁₂₀ , the gas (reforming process gas) is exhausted as vent gas _G6 through the forced open vent control valve _V42 . In the hydrogen purifier 150, the adsorption tower is held at the pressure during normal operation, and since the off-gas OG other than hydrogen _H2 is still adsorbed, the pressure is released.

(Operating procedure C)
FIG. 4 is a system diagram showing an operating procedure C in the operating method of the hydrogen production device 100. As shown in FIG.
As shown in FIG. 4, this operating _procedure C shows a state during transition to standby operation (hydrogen circulation operation). ₄ is filled (replaced) with hydrogen H ₂ for purging. The hydrogen for this purge is supplied from hydrogen source 180 . The hydrogen supply source 180 may be a hydrogen cylinder, or may be introduced with a portion of the hydrogen _H2 of the refined gas _G5 .

(Operating procedure D)
FIG. 5 is a system diagram showing an operating procedure D in the operating method of the hydrogen production device 100. As shown in FIG.
As shown in FIG. 5, this operating procedure D shows a state during standby operation (hydrogen circulation operation), and while maintaining a predetermined heating temperature of the reformer 120, the supply of pure water PW is continued. Meanwhile, the hydrogen circulation operation is performed by circulating the purged hydrogen H ₂ through the hydrogen circulation operation pipe L ₅₁ . In this operation procedure D, the heating temperature of the reformer 120 is lowered to a temperature slightly lower than the heating temperature during normal operation (for example, 50° C. to 150° C.), for example, the heating temperature is 600° C. to 850° C. I try to drive in As a result, the fuel consumption of the source gas _G1 can be reduced.

After the supply of _the raw material _gas G _{1 is} stopped, when the replacement with hydrogen H ₂ in the operation procedure C shown in FIG. The supply of hydrogen H ₂ to the reforming system pipe of the pipe L ₄ is stopped, the circulation operation on-off valve V ₅₁ of the hydrogen circulation operation pipe L ₅₁ is opened, the compressor 105 is turned on, and the pure water PW While continuing the supply of , the hydrogen circulation operation is performed in which the purged hydrogen H ₂ is circulated through the reforming system pipe and the hydrogen circulation operation pipe L ₅₁ .

In FIG. 5, when the pressure detected by the pressure detector P at the outlet of the gas-liquid separator 140, that is, the pressure of the extraction pipe _L4 drops to a predetermined pressure (for example, 0.1 MPaG), the operating procedure shown in FIG. C, the hydrogenation control valve V ₆₁ and the hydrogen on-off valve V ₆₃ are opened, and from the inlet side of the compressor 105 to the reforming system pipes of the raw material pipe L ₁ to the take-out pipe L ₄ , the hydrogen supply source 180 Hydrogen H ₂ is introduced to restore the pressure to a predetermined pressure, and the predetermined pressure (for example, 0.15 MPaG) is maintained during the purge operation.

(Operating procedure E)
This operating procedure E shows a state during transition from standby operation to return to normal operation, and in _FIG . In addition, in order to return the reformer 120 to a predetermined heating temperature (for example, 650° C. to 900° C.) for normal operation, the raw material gas G ₁ is supplied from the raw material supply source 160 to the combustion burner 126, and the reformer Start heating in 120 .

(Operating procedure F)
FIG. 6 is a system diagram showing an operating procedure F in the operating method of the hydrogen production device 100. As shown in FIG.
As shown in FIG. 6, in this operating procedure F, the catalyst reaction temperature of the reformer 120, that is, the detected value of the temperature detector T of the reaction furnace of the reformer 120 is a predetermined temperature (for example, 800° C. to 900° C.). , the hydrogen circulation operation opening/closing valve _V51 is closed to stop hydrogen circulation, the raw material control valve _V1 is opened, and the raw material gas _G1 is introduced. Ultimately, the hydrogen refining device 150 is operated to start producing hydrogen H ₂ , and the operating state of the operating procedure A shown in FIG. 2 is restored.

As described above, the hydrogen production device 100 according to the embodiment of the present invention includes the compressor 105, the desulfurizer 110, the reformer 120, the shift converter 130, the gas-liquid separator 140, and the hydrogen purification device 150. and a hydrogen circulation operation pipe L ₅₁ that loops from the extraction pipe L ₄ connecting between the gas-liquid separator 140 and the hydrogen purification device 150 to the inlet side of the compressor 105 is further provided, and hydrogen _H2 is circulated through the hydrogen circulation operation pipe _L51 while supplying pure water PW or steam in hydrogen circulation operation during standby operation.

As a result, it is possible to significantly reduce the fuel consumption of the raw material gas _G1 in an operating state other than normal operation, for example, during standby operation. The raw material gas G ₁ (for example, city gas) consumption during this standby operation is 7.5, which is 1/10 or less when the rated operation of the hydrogen production device 100 is 100, and can be greatly reduced. The effect of reducing the amount of raw material gas _G1 used could be exhibited. It should be noted that during idling with a low hydrogen production rate, it was about 18 to 20 compared to 100 during rated operation.

In addition, in the hydrogen production apparatus 100 of the embodiment, the startup time from startup to normal operation was about 4 hours, whereas the recovery time from standby operation to normal operation was about 1 hour. I was able to do it quickly. Furthermore, since water vapor is also supplied in addition to the hydrogen _H2 , the catalysts of the reformer 120 and the shift converter 130 are not overreduced.

In the embodiment, in the hydrogen circulation operation during the standby operation, the heating temperature of the reformer 120 may be, for example, 600° C. or higher and 850° C. or lower, and ideally the same temperature as during normal operation (during hydrogen production). . Thereby, the temperature of the reformer 120 can be kept high while suppressing the consumption of the source gas _G1 . Therefore, it is possible to reduce the heat load on various devices of the constituent members 110 to 140 constituting the hydrogen production device 100 and heat exchangers (not shown), thereby extending the life of the devices and devices. However, since the lower the heating temperature of the reformer 120, the more fuel consumption can be suppressed, the heating temperature (holding temperature) during standby operation should be appropriately set in consideration of the frequency and time of standby operation.

Further, by supplying the hydrogen H ₂ and steam heated by the reformer 120, the shift converter 130 can also be indirectly heated. Furthermore, when a separate heater is installed, the temperature may be maintained at about 200° C. to 350° C. by heating with the heater.

In this embodiment, in the hydrogen circulation operation during the standby operation, the pressure of the hydrogen circulation operation pipe _L51 may be set within the range from the atmospheric pressure to the normal operation pressure, for example, 0.3 MPaG or less, preferably 0.2 MPaG. That is, since the hydrogen purifier 150 is not used during the standby operation, the pressure in the circulation pipe can be reduced. Therefore, in the hydrogen circulation operation during the standby operation, it is preferable to lower the pressure so that the power of the compressor 105 used for hydrogen circulation can be reduced.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications, Change is possible.

100 Hydrogen production device 105 Compressor 110 Desulfurizer 120 Reformer 125 Air blower 126 Combustion burner 130 Shift converter 140 Gas-liquid separator 150 Hydrogen refining device 160 Raw material supply source 170 Pure water supply source 180 Hydrogen supply source 190 Offgas holder Vn Opening and closing Valve or regulating valve Ln Piping G ₁ Source gas G ₂ Reformed gas G ₃ Exhaust gas G ₄ Transformed gas G ₅ Purified gas G ₆ Vent gas OG Off gas PW Pure water P Pressure detector T Temperature detector

Claims (7)

A hydrogen production device comprising a compressor, a desulfurizer, a reformer, a shift converter, a gas-liquid separator, and a hydrogen purification device,
Further comprising a hydrogen circulation operation pipe for circulating hydrogen from a pipe connecting between the gas-liquid separator and the hydrogen purification device to the inlet side of the compressor,
In the hydrogen circulation operation during standby operation, the hydrogen is circulated through the hydrogen circulation operation pipe while supplying pure water or steam.
A hydrogen production device characterized by: In hydrogen circulation operation during standby operation, the heating temperature of the reformer is set to 600 ° C. or higher and 850 ° C. or lower,
The hydrogen production apparatus according to claim 1, characterized by: In hydrogen circulation operation during standby operation, the pressure of the hydrogen circulation operation pipe is set to 0.3 MPaG or less,
3. The hydrogen production device according to claim 1 or 2, characterized in that: The hydrogen production apparatus includes a pure water supply source that supplies pure water to a pipe connecting the desulfurizer and the reformer;
and a pure water adjustment valve that adjusts the supply amount of the pure water,
The hydrogen production apparatus according to any one of claims 1 to 3, characterized in that: A method of operating a hydrogen production device comprising a compressor, a desulfurizer, a reformer, a shift converter, a gas-liquid separator, and a hydrogen purification device,
Further comprising a hydrogen circulation operation pipe for circulating hydrogen from a pipe connecting between the gas-liquid separator and the hydrogen purification device to the inlet side of the compressor,
In the hydrogen circulation operation during standby operation, the hydrogen is circulated through the hydrogen circulation operation pipe while supplying pure water or steam.
A method for operating a hydrogen production apparatus, characterized by: In hydrogen circulation operation during standby operation, the heating temperature of the reformer is set to 600 ° C. or higher and 850 ° C. or lower,
The operating method of the hydrogen production apparatus according to claim 5, characterized in that: In hydrogen circulation operation during standby operation, the pressure of the hydrogen circulation operation pipe is set to 0.3 MPaG or less,
7. The operating method of the hydrogen production apparatus according to claim 5 or 6, characterized in that:

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