JP4641138B2 - Hydrogen production method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydrogen production method performed at the time of production of hydrogen for fuel cells , and more particularly to a hydrogen production method for preventing deterioration of a reforming catalyst when a hydrogen production apparatus is started and stopped.
[0002]
[Prior art]
When hydrogen is produced by means such as a steam reforming method or an autothermal reforming method, hydrogen is generated by passing a raw material such as a hydrocarbon through a reformer having a reforming catalyst.
At this time, normally, in order to prevent deterioration of the reforming catalyst due to sulfur poisoning, a desulfurizer is connected in front of the reformer to reduce the sulfur content in the raw material to an allowable concentration or less.
[0003]
The desulfurization method includes a method in which the raw material is in a liquid phase or a gas phase. However, when the liquid phase is used, the contact time of the raw material with the desulfurizing agent can be increased, and the life of the desulfurizing agent can be extended. This is advantageous for downsizing of the vessel.
As a method for performing desulfurization in a liquid phase, for example, a kerosene fraction refined to have a sulfur content of 10 ppm or less is used as a raw material, and a raw material using a Ni-based sorbent at a pressure of atmospheric pressure to less than 1 MPa. There is a method of desulfurizing the kerosene fraction at a temperature of 150 to 300 ° C. (JP-A-1-188404).
In order to further increase the contact time of the raw material with the desulfurizing agent, a so-called up-flow in which the raw material is flowed upward from the bottom of the desulfurizer is effective.
[0004]
By the way, in a desulfurizer in which a part or all of the raw material is desulfurized in a liquid phase state, particularly in the case of upflow, a case where the raw material is always present in the liquid phase in the desulfurizer can be considered. In this case, when starting up the apparatus, when the temperature of the desulfurizer is cooled to a predetermined temperature, a part of the raw material existing in the desulfurizer may become steam.
In this case, since the conventional desulfurizer is directly connected to the reformer, even when the reforming catalyst is not heated to a predetermined temperature and the catalyst function is not exerted, the raw material steam is still in the reformer. There was a problem that would be introduced.
[0005]
Further, at the time of start-up, it is considered that the supply of water vapor, which is important for suppressing carbon deposition, to the reforming catalyst is less than a predetermined amount. When the raw material is introduced in such a state, the raw material is supplied onto the reforming catalyst. Or the deposition of carbon is promoted and the reforming performance of the catalyst is deteriorated.
Furthermore, when the operation is stopped, even if the raw material supply to the desulfurizer is cut, a part of the raw material may become steam and continue to be introduced into the reformer until the desulfurizer cools. . However, during this period, in order to protect the reforming catalyst, the temperature of the reformer cannot be lowered or the supply of steam cannot be stopped.
[0006]
[Problems to be solved by the invention]
In view of the above problems, the present invention prevents the raw material vapor from being supplied to the reformer at the start and stop of the hydrogen production apparatus, and prevents deterioration of the reforming catalyst and shortens the stop time. An object is to provide a method for producing hydrogen .
[0007]
[Means for Solving the Problems]
In order to solve this problem, the present inventor makes it possible to separate the desulfurizer and the reformer as necessary, so that the raw material is not supplied to the reformer when the hydrogen production apparatus is started and stopped. As a result, the inventors have found that this is effective for solving the above-described problems, and have completed the present invention.
[0008]
That is, the invention described in claim 1 includes a desulfurizer in which a part or all of the raw material is desulfurized in a liquid state, a reformer that generates hydrogen from the raw material desulfurized by the desulfurizer, In a hydrogen production method using a hydrogen production apparatus having an auxiliary tank provided in a line for supplying a raw material from a desulfurizer to the reformer, an auxiliary is provided for the line for supplying the raw material from the desulfurizer to the reformer. A tank and a pump are provided, and before the preparation of the reformer at the start of the hydrogen production apparatus, the supply of the raw material by the pump is stopped, and the raw material vapor supplied from the desulfurizer is supplied to the auxiliary tank. The raw material is stored so as not to flow into the reformer, and after the reformer is ready, the raw material is supplied from the auxiliary tank to the reformer by the pump , When stopped , The pump supply of the raw material is stopped by the raw material in the reservoir the vapor of raw material supplied from the desulfurizer to said auxiliary tank to prevent flow into the reformer, the reforming catalyst in the reformer This is a hydrogen production method that does not require heat insulation for protection.
[0009]
Here, it is preferable to detect a raw material level in the auxiliary tank and supply the raw material from the raw material tank via a desulfurizer so that the auxiliary tank does not become empty.
[0010]
The invention according to claim 3 includes a desulfurizer in which a part or all of the raw material is desulfurized in a liquid phase state, and a reformer that generates hydrogen from the raw material desulfurized by the desulfurizer. In the hydrogen production method using the hydrogen production apparatus, a line for supplying the raw material from the desulfurizer to the reformer is provided with a bypass line for returning the raw material from the desulfurizer to the raw material tank via a switching valve, Before preparation of the reformer at the start of the hydrogen production apparatus, the raw material vapor supplied from the desulfurizer is returned to the raw material tank by the bypass line so that the raw material does not flow into the reformer, After the preparation of the reformer, the switching valve is switched to supply raw material steam from the desulfurizer to the reformer, and when the hydrogen production apparatus is stopped, the switching valve is switched to switch the switching valve. Desulfurization A hydrogen production method in which the steam of the raw material supplied from the fuel is returned to the raw material tank by the bypass line so that the raw material does not flow into the reformer, and heat insulation for protecting the reforming catalyst in the reformer is unnecessary It is as.
[0011]
According to these inventions, when the apparatus is started up, the partially evaporated raw material in the desulfurizer is reformed until the temperature rise of the reformer is completed and the reforming catalyst can function. Can be prevented from flowing into the vessel. Therefore, the problem that the raw material adheres on the reforming catalyst and the problem that the carbon deposition is accelerated and the performance of the catalyst deteriorates rapidly can be solved.
Further, even when the operation of the apparatus is stopped, it is possible to prevent the raw material steam that has been generated until the desulfurizer cools after the supply of the raw material to the desulfurizer is stopped from flowing into the reformer. . Therefore, it is possible to shorten the time required for supplying steam and maintaining the temperature of the reformer, which has been performed for the protection of the reforming catalyst until the desulfurizer is cooled, and shortening the apparatus stop time. Can do.
[0012]
In the above hydrogen production method , the raw material is in a liquid phase at normal temperature under atmospheric pressure, for example, a hydrocarbon fuel such as naphtha, gasoline, kerosene, and light oil, an alcohol fuel such as methanol and ethanol, or a comparison A hydrocarbon or ether-based fuel such as LPG (liquefied petroleum gas) or DME (dimethyl ether), which becomes a liquid phase when pressurized under a low pressure (less than 1 MPa), is used. Of these, inexpensive kerosene is preferred because of its supply system.
[0013]
Moreover, when kerosene is used as a raw material, the desulfurization conditions are preferably such that the desulfurization temperature is 150 ° C. or higher and 300 ° C. or lower. This is because it is necessary to set the temperature so that the desulfurization function of the desulfurization agent can be exhibited. For example, with a Ni-based desulfurizing agent, it is preferable to heat to 100 ° C or higher.
Further, the desulfurization pressure is preferably 0.1 MPa or more and less than 1.0 MPa. This is because it is effective to apply pressure in order to suppress the vaporization of kerosene at a temperature at which desulfurization performance can be exhibited. However, at 1.0 MPa or more, there are disadvantages such as an increase in the cost of the desulfurizer from the viewpoint of pressure resistance of the desulfurizer. Preferably, it is 0.2 MPa or more and 0.7 MPa or less.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
Note that the present invention is not limited to these embodiments.
[First embodiment]
FIG. 1 is a schematic view of a hydrogen production apparatus for explaining a first embodiment of the present invention.
The hydrogen production apparatus 1 includes a raw material tank 11, a desulfurizer 12, a raw material vaporizer 13, a reformer 14, a water tank 15, and an evaporator 16 as main components. In this hydrogen production apparatus 1, a bypass line 18 that branches from a pipe line connecting the desulfurizer 12 and the raw material vaporizer 13 and connects to the raw material tank 11 is provided.
[0015]
The piping connecting the bypass line 18, the desulfurizer 12 and the reformer 14 can be switched in the flow direction by the switching valve 17, and the flow of the raw material from the desulfurizer can be changed when necessary, such as when starting or when the apparatus is stopped. Can be switched.
The raw material vaporizer 13 needs to be installed downstream of the switching valve 17. When pressurizing the desulfurizer 12, it is preferable to provide the bypass line 18 downstream of the pressure control device such as the pressure regulating valve V1.
[0016]
The raw material tank 11 is in a liquid phase at atmospheric temperature under atmospheric pressure, for example, hydrocarbon fuels such as naphtha, gasoline, kerosene and light oil, alcohol fuels such as methanol and ethanol, or relatively low pressure pressurization. A hydrocarbon or ether-based fuel such as LPG (liquefied petroleum gas), DME (dimethyl ether), etc., which becomes a liquid phase due to (less than 1 MPa) is charged.
[0017]
The desulfurizer 12 removes sulfur components in the raw material in order to prevent sulfur poisoning of the reforming catalyst in the reformer 14.
The raw material vaporizer 13 vaporizes a raw material such as hydrocarbon, mixes it with water vapor supplied from the evaporator 16, and supplies this mixed raw material to the reformer 14.
The reformer 14 is a device that generates hydrogen from a mixed raw material such as hydrocarbon, and a reforming catalyst is provided therein.
[0018]
Next, the hydrogen production method according to this embodiment will be specifically described.
(At the time of hydrogen production equipment startup)
When the hydrogen production apparatus 1 is started, it is necessary to raise the temperature of the desulfurizer 12, the reformer 14, and the like. At this time, if the raw material is present in the desulfurizer 12, the switching valve 17 is switched until the temperature rise is completed, and the raw material vapor flows from the outlet of the desulfurizer 12 toward the raw material tank 11. Keep flowing.
Thus, the raw material vapor generated from the desulfurizer 12 at the time of temperature rise is returned to the raw material tank 11 and is not supplied to the reformer 14. Accordingly, since the raw material is not mixed before the preparation of the reformer 14 is completed, the problem of deterioration of the reforming performance of the reforming catalyst is solved.
[0019]
(Desulfurization process)
The desulfurizer 12 is filled with a desulfurizing agent. As the desulfurizing agent, for example, activated carbon, zeolite, or a metal-based adsorbent is preferable. When the raw material is a heavy hydrocarbon such as kerosene, a Ni-based desulfurizing agent is preferable as disclosed in JP-A-2001-279255.
In order to perform desulfurization, it is necessary to set the temperature so that the desulfurization function of the desulfurizing agent can be exhibited. For example, with a Ni-based desulfurizing agent, it is preferable to heat to 100 ° C. or higher, and when the raw material is kerosene, it is preferably set to 150 ° C. or higher and 300 ° C. or lower.
As a method for heating the desulfurizer 12, a method of heating the raw material before entering the desulfurizer 12 and a method of heating the desulfurizer 12 from the outside are effective.
[0020]
In order to increase the sulfur adsorption amount of the desulfurizing agent and extend the life of the reforming catalyst, part or all of the raw material is desulfurized in a liquid phase. Thereby, the contact time between the desulfurizing agent and the raw material can be lengthened, and the sulfur concentration in the raw material can be lowered to a low concentration with a small amount of the desulfurizing agent.
In order to make the contact time longer, a desulfurization method in which the flow of the raw material is made to flow upward from the bottom to form a liquid surface in the desulfurizer is preferable. In this case, a liquid phase always exists in the desulfurizer.
[0021]
In order to make part or all of the raw material into a liquid phase, it is preferable to pressurize the desulfurizer 12 at a temperature at which the performance of the desulfurizing agent can be exhibited in order to suppress the vaporization of the raw material. This pressure depends on the raw material used, but when kerosene is used as the raw material, it is preferably 0.1 MPa or more and less than 1.0 MPa. When the pressure is 1.0 MPa or less, there is a demerit in cost and the like from the viewpoint of pressure resistance.
[0022]
When desulfurization is performed by pressurizing the desulfurizer 12, if the raw material supply is reduced (turned down) during operation, the following problems may occur. That is, when a part of the gas phase is present in the desulfurizer, if the pressure is reduced due to a decrease in the supply of the raw material, the gas phase part expands, so that the volume of the gas phase part in the desulfurizer increases. As a result, the liquid phase may be pushed out of the desulfurizer. In this case, although the supply amount of the raw material by the raw material pump P1 is decreasing, the flow rate of the raw material coming out of the desulfurizer 12 becomes larger than the set value of the pump P1.
[0023]
Normally, the supply of water vapor is reduced as the supply of raw material by the raw material pump P1 is reduced, but the flow rate of the raw material coming out of the desulfurizer 12 is not immediately reduced. For this reason, the steam / carbon ratio (S / C ratio), which is the molar ratio of water vapor to the carbon constituting the raw material, may be reduced, leading to deterioration of the reforming catalyst.
Therefore, even if the supply amount of the raw material by the raw material pump is reduced, the supply amount of water vapor is maintained for a certain period of time, the flow amount of the raw material from the desulfurizer is detected and the water vapor amount is adjusted, or the raw material flow is It is necessary to take measures such as predicting the amount and supplying an amount of water vapor that can always maintain the S / C ratio necessary for protecting the reforming catalyst.
[0024]
If the active metal component, which is an active component in the reforming catalyst, is present in the raw material even if a small amount of sulfur is present, it binds to the sulfur and accumulates with time, and the catalyst deteriorates with time. For this reason, in order to use the reforming catalyst stably for a long period of time, the sulfur component in the raw material is preferably 0.2 ppm or less, particularly preferably 0.05 ppm or less.
[0025]
(Reforming process)
After the start of the desulfurization process is completed, the preparation of the reformer 14 and the supply of steam is completed, and then the switching valve 17 is switched so that the raw material flows through the pipeline from the outlet of the desulfurizer 12 to the raw material vaporizer 13. Like that.
The raw material that has undergone the desulfurization step needs to be vaporized before the raw material is supplied to the reformer 14. In the raw material vaporizer 13, as a method of vaporizing, the vaporizer 13 is heated from the outside to vaporize the raw material, or when steam or air mixed with the raw material is heated to a predetermined temperature and mixed with the raw material A method of vaporizing by applying heat can be considered.
[0026]
The reformer 14 is a device that generates hydrogen from a raw material such as a hydrocarbon, and a reforming catalyst is provided therein.
When hydrogen is produced from a raw material using a reformer for a fuel cell or the like, it is usually performed by any one of a steam reforming method, a partial oxidation method, and an autothermal reforming method. All of these reaction methods are performed using a reforming catalyst.
As the reforming catalyst, for example, a noble metal such as Ru, Ph, Pt, or Pd, or a metal such as Ni or Co is used as the active metal component.
[0027]
In the steam reforming method, the raw material is mixed with steam, and the reaction is carried out on the reforming catalyst at a temperature of about 700 to 800 ° C. and an S / C ratio of 2 to 4. The higher the S / C ratio value, the more carbon deposition on the catalyst is suppressed and the life of the reforming catalyst is extended. However, in order to generate excessive steam, more heat must be input, This will reduce the efficiency of the equipment. Therefore, it is usually set to a minimum value that can suppress carbon deposition on the catalyst. This value varies depending on the catalyst used, but is about S / C = 2.5 to 3.5.
[0028]
The partial oxidation method is a method of introducing oxygen (air) into a raw material. Usually, the molar ratio of oxygen to carbon in the raw material (O ₂ / C ratio) is 0.4 to 0.6, and the reaction temperature is 800 to 800. Perform at 1000 ° C.
The autothermal reforming method is a method in which steam reforming and partial oxidation are combined. Usually, the S / C ratio is 0.5 to 4, the O ₂ / C ratio is 0.4 to 0.6, and the reaction temperature. Is performed at 700 to 900 ° C.
[0029]
In the present embodiment, the water vapor supplied from the evaporator 16 and the vaporized raw material pass through the reformer 14 to produce a hydrogen rich gas.
[0030]
(Device stop process)
When the apparatus is stopped, the supply of the raw material by the raw material pump P1 is stopped, and cooling of the desulfurizer 12 and the like is started. At this time, the switching valve 17 is switched so that the raw material flows through the bypass line 18 from the outlet of the desulfurizer 12 toward the raw material tank 11.
Thus, since the raw material vapor flows through the bypass line 18 into the raw material tank 11 until the temperature of the desulfurizer 12 decreases, the raw material does not flow into the reformer 14. Therefore, it is possible to shorten the time required for supplying steam and maintaining the temperature of the reformer 14 that is performed for protecting the reforming catalyst until the desulfurizer 12 is cooled, and also shortening the apparatus stop time. can do.
[0031]
[Second Embodiment]
FIG. 2 is a schematic view of a hydrogen production apparatus including a desulfurizer for explaining a second embodiment of the present invention.
The hydrogen production apparatus 2 includes a raw material tank 11, a desulfurizer 12, a raw material vaporizer 13, a reformer 14, a water tank 15, an evaporator 16, and an auxiliary tank 21 provided between the desulfurizer 12 and the raw material vaporizer 13. Is the main component.
In addition, the same code | symbol is attached | subjected to the same part as the hydrogen production apparatus 1 shown in FIG. 1, and detailed description of the said part is abbreviate | omitted.
[0032]
In the hydrogen production apparatus 2 shown in FIG. 2, the line from the desulfurizer 12 is not directly connected to the reformer 14 but is connected to the auxiliary tank 21. The auxiliary tank 21 is connected to the reformer 14 via the pump P3 and the raw material vaporizer 13. Here, the raw material vaporizer 13 needs to be installed downstream of the auxiliary tank 21 in order to vaporize with pressurized steam and to uniformly mix the steam and the raw material.
[0033]
The pumps P1 and P3 are installed in the raw material tank 11 and the auxiliary tank 21, respectively. The raw material supply by these pumps P1 and P3 may be interlocked or may be separate. When separated, the means for detecting the raw material level in the auxiliary tank 21 and supplying the necessary amount of raw material from the raw material tank 11 via the desulfurizer 12 is effective so that the auxiliary tank 21 does not become empty. .
In the present embodiment, since the operation of the desulfurizer 12 and the operation of the reformer 14 are separated, special measures can be taken if the raw material supply amount is reduced during operation so that the auxiliary tank 21 does not become empty. There is no need to take.
[0034]
Thereby, the raw material steam generated from the desulfurizer 12 at the start-up flows into the auxiliary tank 21 and stays in the tank, so that it is not supplied to the reformer 14. Therefore, since the raw material is not mixed before the preparation of the reformer 14 is completed, the problem of deterioration of the reforming performance of the reforming catalyst is solved.
Further, until the temperature of the desulfurizer 12 decreases, the generated raw material steam flows into the auxiliary tank 21 and remains there. Therefore, it does not flow into the reformer 14, and shortens the time required to supply the steam and maintain the temperature of the reformer 14 after stopping the raw material pump P1, which has been performed to protect the reforming catalyst. And the apparatus stop time can be shortened.
[0035]
【Example】
Examples of the present invention will be described below.
The configuration of the desulfurization apparatus used in this example is shown in FIG.
The desulfurization apparatus 3 includes a raw material tank 11, a desulfurizer 12, and a raw material trap tank 31 as main components, and the raw material trap tank 31 side is a pipe line that leads to the reformer in the hydrogen production apparatus. Between the desulfurizer 12 and the raw material trap tank 31, a bypass line 18 connected to the raw material tank 11 is branched from a pipe line connecting the desulfurizer 12 and the raw material trap tank 31 via the switching valve 17. Yes. Thereby, by switching the switching valve 17, the flow can be switched between the raw material trap tank 31 side and the raw material tank 11 side.
The desulfurizer 12 is heated by an electric heater 32.
Using this desulfurization apparatus 3, the outflow of the raw material from the desulfurizer 12 was observed when the apparatus was started and stopped. The experimental conditions are as follows.
[0036]
Raw material: Kerosene (JIS No. 1) was used. This kerosene had a sulfur content of 48 ppm by weight.
Desulfurizer: A cylindrical one having an inner diameter of 7 cm and a length of about 80 cm was used, and a sintered metal filter (diameter: 100 μm) was disposed at the inlet and outlet of the desulfurizer.
Desulfurization agent: A Ni-based desulfurization agent containing 70% by weight of Ni in terms of metal was used.
3 L of this desulfurizing agent was filled in a desulfurizer and previously hydrogen reduced at 300 ° C.
Thereafter, kerosene desulfurized in advance was supplied to the desulfurizer so that the desulfurizing agent layer was completely filled with kerosene at room temperature. Thereby, the oxidation of the desulfurizing agent can be prevented. In this experiment, the inside of the desulfurizer was completely liquid-sealed.
Desulfurization conditions: the desulfurization pressure was 0.2 MPa, the temperature was 200 ° C., and the liquid reference space velocity (LHSV) of kerosene was 0.1 h ⁻¹ .
[0039]
・ Start-up experiment The inside of the desulfurizer before start-up was at normal pressure and room temperature. Before the start-up, the switching valve 17 is switched so that kerosene flows from the desulfurizer 12 to the bypass line 18. The pressure regulating valve V1 in the desulfurizer outlet line was set so that the pressure in the desulfurizer 12 was 0.2 MPa.
After that, when the heating of the desulfurizer 12 was started, the pressure in the desulfurizer increased as the temperature rose and reached 0.2 MPa at 150 ° C. From this point, kerosene began to flow into the bypass line 18 and 30 cc of kerosene flowed into the raw material tank 11 from the bypass line 18 until the temperature of the desulfurizer 12 reached a predetermined 200 ° C.
In this state, the switching valve 17 was switched and switched to the raw material trap tank 31 side, and kerosene was supplied by the pump P1 at 5 cc / min. It was confirmed that the kerosene flowed out from the desulfurizer 12 to the fuel and trap tank 31 stably at a flow rate of 5 cc / min without delay in response time immediately after the pump was started.
[0037]
From the above, even when a reformer is connected instead of the raw material trap tank 31, kerosene does not flow into the reformer at startup, and the desulfurizer 12 and the reformer After the preparation is completed, it is confirmed that the desulfurized kerosene can be supplied to the reformer without delay in response time by switching the switching valve 17 and connecting it to the reformer and supplying a predetermined amount of raw material with the pump P1. did it.
[0038]
Stop experiment After the above operation at 5 cc / min, the stop operation was performed. First, the supply of kerosene by the pump P1 was stopped, and the heating of the electric heater 32 of the desulfurizer 12 was cut.
Next, the switching valve 17 was switched and connected to the bypass line 18 side. Kerosene flowed out of the bypass line 18 for about 20 minutes until the desulfurizer 12 was cooled, and its amount was 20 cc.
When not connected to the bypass line 18, it takes 30 minutes from the stop of kerosene supply to the stop of steam supply, but when connected to the bypass line 18, the time required to stop the steam is 10 minutes, A significant time saving was achieved.
As a result, if it is left connected to the reformer 14, the supply of steam cannot be cut while the kerosene is flowing out, but if it is connected to the bypass line 18 as described above, the steam to the reformer 14 It has been found that the supply of can be stopped in a short time and heating of the reformer 14 can be stopped.
[0039]
【The invention's effect】
According to the present invention, there is provided a hydrogen production method capable of preventing the raw material steam from being supplied to the reformer at the start and stop of the hydrogen production apparatus , preventing deterioration of the reforming catalyst, and shortening the stop time. Can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic view of a hydrogen production apparatus including a desulfurizer for explaining a first embodiment of the hydrogen production method of the present invention.
FIG. 2 is a schematic view of a hydrogen production apparatus including a desulfurizer for explaining a second embodiment of the hydrogen production method of the present invention.
FIG. 3 is a schematic view of a desulfurization apparatus used in Examples.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 2 Hydrogen production apparatus 11 Raw material tank 12 Desulfurizer 13 Raw material vaporizer 14 Reformer 15 Water tank 16 Evaporator 17 Switching valve 18 Bypass line 21 Auxiliary tank 3 Desulfurization apparatus 31 Raw material trap tank 32 Electric heater

Claims (5)

In a hydrogen production method using a hydrogen production apparatus having a desulfurizer in which part or all of a raw material is desulfurized in a liquid phase and a reformer that generates hydrogen from the raw material desulfurized by the desulfurizer ,
An auxiliary tank and a pump are provided in a line for supplying raw materials from the desulfurizer to the reformer,
Before the reformer is ready at the time of startup of the hydrogen production apparatus, the supply of the raw material by the pump is stopped, and the raw material vapor supplied from the desulfurizer is stored in the auxiliary tank so that the raw material is reformed. After the reformer is ready, the raw material is supplied from the auxiliary tank to the reformer by the pump.
When the hydrogen production apparatus is stopped, the supply of the raw material by the pump is stopped, the vapor of the raw material supplied from the desulfurizer is accumulated in the auxiliary tank so that the raw material does not flow into the reformer, and the reforming is performed. A method for producing hydrogen, characterized by eliminating the need for heat insulation for protecting the reforming catalyst in the reactor.   2. The hydrogen production method according to claim 1, wherein the raw material level in the auxiliary tank is detected so that the auxiliary tank does not become empty, and the raw material is supplied from the raw material tank via a desulfurizer. In a hydrogen production method using a hydrogen production apparatus having a desulfurizer in which part or all of a raw material is desulfurized in a liquid phase and a reformer that generates hydrogen from the raw material desulfurized by the desulfurizer ,
A line for supplying the raw material from the desulfurizer to the reformer is provided with a bypass line for returning the raw material from the desulfurizer to the raw material tank via a switching valve,
Before preparation of the reformer at the start of the hydrogen production apparatus, the raw material vapor supplied from the desulfurizer is returned to the raw material tank by the bypass line so that the raw material does not flow into the reformer. After the preparation of the reformer, the switching valve is switched to supply the raw material steam from the desulfurizer to the reformer,
When the hydrogen production apparatus is stopped, the switching valve is switched to return the raw material vapor supplied from the desulfurizer to the raw material tank by the bypass line so that the raw material does not flow into the reformer, and the reformer A method for producing hydrogen, characterized in that no heat retention for protecting the reforming catalyst is required.   The raw material is kerosene, a desulfurization pressure is 0.1 MPa or more and less than 1.0 MPa, and a desulfurization temperature is 150 ° C. or more and 300 ° C. or less. Hydrogen production method.   The hydrogen production method according to claim 1, wherein the desulfurization agent in the desulfurizer is a Ni-based desulfurization agent.

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