JP2002020102A - Method for starting and method for stopping hydrogen producing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for starting and a method for stopping a hydrogen producing device by which the operation cost or the installation area is reduced and works such as the exchange of nitrogen cylinder or hydrogen cylinder, which involves danger, are rendered unnecessary. SOLUTION: When starting, a combustion reaction occurs with hydrogen and air in a catalytic combustion part 14 and when the temperature of a steam reforming part 13 is raised and reaches the starting temperature, steam and a raw material hydrocarbon are supplied, a hydrogen-containing gas after the gas reforming detours around a PSA part 17 until the gas is stabilize and is supplied to the PSA part 17 after stabilized. When stopping, the PSA part 17 is stopped, the concentration of oxygen in a waste gas from the catalytic combustion part 14 is reduce and the waste gas is circulated in a reaction system to reduce the concentration of an inflammable gas and finally replaced with nitrogen, carbon dioxide or steam and the operation is stopped. As a result, the operation cost or the installation area is reduced and the works such as the exchange of nitrogen or hydrogen cylinder are rendered unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for starting and stopping a hydrogen production apparatus including a steam reforming section, or a hydrogen production apparatus used for a fuel cell system or other uses.

[0002]

2. Description of the Related Art A general hydrogen production apparatus is started and stopped by:
Use an inert gas such as nitrogen filled in a cylinder.
During startup, hydrogen is supplied from a hydrogen cylinder as a hydrogenation gas for heating and desulfurization using a burner while flowing nitrogen into the system from the cylinder. During shutdown, the temperature is reduced after replacing the combustible gas with nitrogen. With this method, oxidation of the catalyst can be prevented, and operation can be performed safely.
However, disadvantages of this method are that a nitrogen cylinder, a hydrogen cylinder, and the like are required, resulting in high costs and a large installation space. In addition, when the inert gas is exhausted, starting and stopping operations cannot be performed, and replacement of the cylinder is troublesome and high pressure, which is dangerous. In addition, it is conceivable that a nitrogen cylinder or hydrogen cylinder cannot be installed due to a small device (for example, a hydrogen production device for home or on-vehicle fuel cells) and other circumstances, and furthermore, the infrastructure for hydrogen and nitrogen is not provided. There are also problems such as.

[0003] It is also conceivable that after the supply of the raw material hydrocarbons is stopped, the temperature is gradually lowered to such an extent that the catalyst is not oxidized, and then the air is replaced with air. However, according to this method, since air is supplied into the combustible gas, there is a concern that there is a danger. Further, the heating of the steam reforming section is generally performed using a burner, but there is a problem that if the concentration of combustible gas decreases, combustion stops.

[0004]

SUMMARY OF THE INVENTION The present invention has been made on the background of the prior art, and a hydrogen production apparatus does not require a cylinder such as a nitrogen cylinder or a hydrogen cylinder. To provide a start-up method of a hydrogen production apparatus and a method for stopping the hydrogen production apparatus, which can reduce the size of the apparatus because the installation space of the cylinder is not required, and can reduce the time required for replacing the cylinder which is troublesome and dangerous. Things. In addition, the present invention is a fuel cell for home use and a vehicle-mounted fuel cell in which a cylinder cannot be installed, and other fuel cells, an on-site hydrogen production device and the like, a hydrogen cylinder and a nitrogen cylinder, a burner,
It is an object of the present invention to provide a method for safely starting and stopping a hydrogen production apparatus without using special electric power or the like.

[0005]

According to the first aspect of the present invention,
A desulfurization unit that removes the sulfur content of the raw hydrocarbon, a steam reforming unit that generates a hydrogen-containing gas by adding steam to the raw hydrocarbon desulfurized in the desulfurization unit, and generates a hydrogen-containing gas, and the hydrogen-containing gas. A gas conversion unit for converting carbon monoxide therein into carbon dioxide and hydrogen, a PSA unit for purifying the hydrogen-containing gas gas-converted in the gas conversion unit to high-purity hydrogen, a hydrogen-containing combustible gas and air In the start-up method of the hydrogen production apparatus comprising a catalytic combustion unit that heats the steam reforming unit by causing a combustion reaction with oxygen, the catalytic combustion unit includes:
The steam reforming section is heated by supplying high-purity hydrogen and air to cause a catalytic combustion reaction, and when the temperature of the steam reforming section reaches the start temperature of steam reforming, the steam and the steam are reformed. It is a starting method of the hydrogen production apparatus which starts supply of the above-mentioned raw material hydrocarbon.

According to a second aspect of the present invention, the hydrogen-containing gas bypasses the PSA section and is supplied to the catalytic combustion section for combustion until the hydrogen content of the hydrogen-containing gas after the gas conversion is stabilized. After the hydrogen-containing gas has stabilized, the PSA
The method for starting a hydrogen production apparatus according to claim 1, wherein the supply to the section is started to purify the high-purity hydrogen.

According to a third aspect of the present invention, there is provided a method for starting a hydrogen production apparatus according to the first or second aspect, wherein the high-purity hydrogen is supplied to a fuel cell.

According to a fourth aspect of the present invention, the desulfurization section is a hydrodesulfurization section for adding hydrogen for hydrodesulfurization to a raw material hydrocarbon and then desulfurizing and removing a sulfur content in the raw material hydrocarbon. A method for starting a hydrogen production apparatus according to any one of claims 1 to 3.

According to a fifth aspect of the present invention, there is provided the hydrogen production apparatus according to any one of the first to fourth aspects, further comprising a hydrogen storage unit for storing high-purity hydrogen obtained from the PSA unit. This is the activation method.

The invention according to claim 6 is the method for starting a hydrogen production apparatus according to claim 5, wherein high-purity hydrogen in the hydrogen storage unit is supplied to the hydrodesulfurization unit as hydrogen for hydrodesulfurization.

According to a seventh aspect of the present invention, there is provided a desulfurization section for removing a sulfur content of a raw material hydrocarbon, and a steam containing gas is produced by adding steam to the raw material hydrocarbon desulfurized in the desulfurization section. Steam reforming section, a gas conversion section for converting carbon monoxide in the hydrogen-containing gas into carbon dioxide and hydrogen, and a PSA section for purifying the hydrogen-containing gas gas-converted in the gas conversion section to high-purity hydrogen. In a method for stopping a hydrogen production apparatus comprising: a combustion reaction between a hydrogen-containing combustible gas and oxygen in the air to heat the steam reforming unit; and stopping the PSA unit. The hydrogen-containing gas after the gas conversion was bypassed to the PSA section, supplied to the catalytic combustion section and burned, and the amount of air supplied to the catalytic combustion section was gradually reduced, and was discharged from the catalytic combustion section. Reduces oxygen concentration in combustion gas And supplying the combustion gas from the catalytic combustion section into the reaction system of the hydrogen production apparatus, while gradually reducing the supply amounts of the raw material hydrocarbons and steam, reducing the concentration of the combustible gas in the reaction system. After that, the supply of air to the catalytic combustion section is stopped, and after the temperature in the reaction system decreases, the hydrogen production apparatus is stopped, and the method for stopping the hydrogen production apparatus is performed.

The invention according to claim 8 is the method according to claim 7, wherein the high-purity hydrogen is supplied to a fuel cell.

According to a ninth aspect of the present invention, the desulfurization section is a hydrodesulfurization section for adding hydrogen for hydrodesulfurization to a raw material hydrocarbon and then desulfurizing and removing a sulfur content in the raw material hydrocarbon. A method for stopping a hydrogen production apparatus according to claim 7 or 8.

[0014]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram showing a starting method of a hydrogen production apparatus according to one embodiment of the present invention. FIG.
FIG. 3 is a system diagram showing a method for stopping the hydrogen production apparatus according to one embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a hydrogen production apparatus using city gas, LPG, kerosene, methanol, or the like as a raw material. Here, city gas is used. Hereinafter, each component of the hydrogen production apparatus 10 will be described. Reference numeral 11 denotes a city gas that is subjected to hydrodesulfurization (desulfurization) 12
Compressor. The hydrodesulfurization unit 12 is divided into an upstream hydrogenation catalyst layer and a downstream desulfurization agent layer. In the hydrodesulfurization unit 12, a part of the high-purity hydrogen (purified hydrogen) separated by pressure adsorption and separation in the PSA unit 17 described later is added to the city gas supplied by the compressor 11 as hydrogen for hydrodesulfurization. The sulfur content of city gas is desulfurized.

As the hydrogenation catalyst, NiM in which an oxide or sulfide such as nickel-molybdenum or cobalt-molybdenum is supported on a carrier such as silica or alumina is used.
ox catalyst or CoMox catalyst. Under low pressure, nickel-molybdenum catalysts are preferred. Also,
As the desulfurizing agent, zinc oxide, a nickel-based sorbent, or the like may be used alone or appropriately supported on a carrier. In the hydrogenation catalyst layer, sulfur in the raw hydrocarbon is hydrogenated to generate hydrogen sulfide. The reaction temperature is 300 to 400 ° C., and by performing desulfurization using high-purity hydrogen, the desulfurization effect is increased and the life of the reforming catalyst is extended. In the desulfurizing agent layer, for example, a reaction of H ₂ S + ZnO = ZnS + H ₂ O occurs. The raw hydrocarbon after desulfurization is supplied to the steam reforming section 13. Here, a method of hydrodesulfurizing a sulfur compound in a raw material hydrocarbon is employed, but a method of directly adsorbing a sulfur compound to a catalyst, for example, may also be used. Examples of the catalyst in this case include metals such as nickel, zinc, and copper, oxides and sulfides thereof, and zeolites and activated carbon. As the activated carbon, those impregnated with an alkali metal such as sodium, activated carbon adsorbing bromine, and the like can be used.

The steam reforming section 13 produces a high-concentration hydrogen-containing gas by adding water or steam to the desulfurized city gas, and further contacting a reforming catalyst to perform steam reforming. The steam reforming section 13 is filled with a reforming catalyst in which an element such as ruthenium or nickel is supported on a carrier such as alumina or silica. Among these, a ruthenium-based catalyst is preferable when a raw material such as kerosene having a large number of carbon atoms is used, because carbon deposition can be suppressed. In the steam reforming section 13, steam reforming of the desulfurized hydrocarbon is performed. The reaction here is shown below.

Reference numeral 14 denotes a catalytic combustion section which is provided around the steam reforming section 13 and catalytically combusts hydrogen and oxygen in the air. The catalytic combustion unit 14 may be provided inside the steam reforming unit 13, or may be a heat exchange type reactor having high heat conductivity. As the catalyst of the catalytic combustion unit 14, a catalyst in which platinum, palladium, or the like is supported on alumina or the like is used. The temperature of the steam reforming section 13 at the time of starting the hydrogen production apparatus 10 is 380 ° C. or more, for example, 38 ° C.
0-500 ° C. If the temperature is lower than 380 ° C., the reaction conversion rate is low, and when the combustible gas containing hydrogen, methane, carbon monoxide, etc. is reused in the catalytic combustion section, the oxidation reaction of these combustible gases does not proceed. Occurs. And finally, about 800 ° C. is preferable.

Reference numeral 15 denotes a gas shift section filled with a shift catalyst for converting carbon monoxide in the high-concentration hydrogen-containing gas produced in the steam reforming section 13 into carbon dioxide and hydrogen. As the shift catalyst, iron-chromium (for example, Fe ₂
O ₃ -Cr ₂ O ₃ catalyst) and, copper - copper-based catalyst is an oxide such as zinc is used. The reaction temperature was Fe ₂ O ₃ −
In the case of a Cr ₂ O ₃ catalyst, the temperature is preferably 300 to 450 ° C., and for the copper catalyst, the temperature is preferably 200 to 250 ° C. The reaction here is CO + H ₂ O = CO ₂ + H ₂ .

Reference numeral 16 denotes a KO (knockout) drum which cools the high-concentration hydrogen-containing gas gas-converted in the gas conversion section 15 and condenses and removes moisture contained in the gas. Reference numeral 17 denotes a PSA (Pressure Swing A) for pressure-adsorbing and separating high-purity hydrogen from a high-concentration hydrogen-containing gas after gas conversion from which water vapor has been removed.
bsorption part). The pressure adsorption separation mentioned here is a method in which an impurity gas other than hydrogen is adsorbed and removed from a high-concentration hydrogen-containing gas by an adsorbent, and high-purity hydrogen that has passed without being adsorbed is purified. Reference numeral 18 denotes a PSA unit 17
It is a hydrogen storage tank (hydrogen storage unit) for storing high-purity hydrogen purified in the above. The hydrogen storage tank 18 is capable of storing a necessary amount of hydrogen for catalytic combustion and hydrogenation gas at the time of startup, and is preferably a tank filled with a hydrogen storage alloy in order to achieve compactness.

Reference numeral 19 denotes a polymer electrolyte fuel cell (hereinafter, referred to as a fuel cell 19) to which high-purity hydrogen temporarily stored in the hydrogen storage tank 18 is supplied. As the use, for example, a home fuel cell, an in-vehicle fuel cell and the like can be mentioned. This fuel cell 19 has an electrolyte material. This electrolyte material generally has a polymer ion exchange membrane having a sulfonic acid group as an ion exchange group. When hydrogen (fuel) and oxygen (oxidant) are supplied to the cell, electric energy can be extracted to the outside by the following reaction.

H ₂ → 2H + + 2e ⁻ (1) 1 / 2O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O (2) (All reactions) H ₂ + 1 / 2O ₂ → H ₂ O (3) According to the equation (1) The generated hydrogen ions move together with water (xH ₂ O) via ion exchange groups in the polymer ion exchange membrane, and react with oxygen as shown in formula (2) to form water (H ₂ O).
O). The air (oxygen) discharged from the fuel cell 19 may be supplied to the catalytic combustion unit 14. PS
The high-purity hydrogen from which impurities have been removed in the part A 17 is supplied to the fuel cell 19 after water content is adjusted, and electric energy is obtained while generating water. This PSA unit 17
Impurities in the high-purity hydrogen separated and purified by 10 ppm
It is as follows. Therefore, the possibility that the electrodes of the polymer electrolyte fuel cell 19 are poisoned by carbon monoxide and the cell performance is reduced is eliminated. Then, part of the high-purity hydrogen obtained in the PSA unit 17 can be reused as hydrogen for hydrodesulfurization in the hydrodesulfurization unit 12. The excess high-purity hydrogen of the fuel cell 19 can also be used as hydrogen for hydrodesulfurization.

Reference numeral 20 denotes an off-gas holder (off-gas storage unit) for temporarily storing the off-gas adsorbed and removed by the PSA unit 17, and supplies the off-gas to the catalytic combustor 14 as fuel for heating the steam reforming unit 13. Is done. In addition, the high-concentration hydrogen-containing gas from which the moisture has been removed by the KO drum 16 and having undergone gas conversion is supplied to the off-gas holder 20 bypassing the PSA unit 17 at the time of startup and stop. further,
The surplus gas of unreacted hydrogen in the fuel cell 19 is also temporarily stored in the off-gas holder 20 and supplied to the catalytic combustion unit 14,
It is used as a heat source in the reaction system.

The symbol E1 represents the pressure from the compressor 11 to the hydrodesulfurization unit 1
This is a heat exchanger that heat-exchanges the city gas supplied to 2 and the combustion gas from the catalytic combustion unit 14 to increase the city gas to a hydrodesulfurization temperature of 300 to 400 ° C. The symbol E2 represents water supplied to the steam reforming section 13 by the supply pump P,
The heat exchanger exchanges heat with the combustion gas from the catalytic combustion unit 14 to generate steam for steam reforming. Symbol E3
Exchanges heat between the high-concentration hydrogen-containing gas (200 to 350 ° C.) gas-converted in the gas conversion unit 15, the excess high-purity hydrogen from the fuel cell 19, and the off-gas stored in the off-gas holder 20, This is a heat exchanger that cools high-concentration hydrogen-containing gas after gas conversion to near normal temperature. Heat exchanger E3
As a result, the combustible gas containing hydrogen, methane, carbon monoxide, and the like, which is reused in the catalytic combustion unit 14, is heated and heated to 380 ° C. or higher. If the temperature is lower than 380 ° C., the oxidation reaction of methane is not performed smoothly.

The hydrogen production apparatus 10 here comprises a compressor 11, a hydrodesulfurization section 12, a steam reforming section 13, a catalytic combustion section 14, a gas conversion section 15, a PSA section 17, and a hydrogen storage tank 18. Have been. However, the gas conversion unit 15 may not be provided after the steam reforming unit 13,
Providing a gas shift section increases the amount of hydrogen and reduces carbon monoxide. At the same time, adsorption and separation of high-purity hydrogen in the PSA section is performed at a relatively low temperature of normal temperature. It is preferable to install them. In the figure, reference numeral 21
Is a four-way valve type flow switching device (hereinafter referred to as a four-way valve).

The starting method and the stopping method of the hydrogen production apparatus 10 having the above configuration will be described in detail below. First, FIG.
The operation at the time of startup will be described based on FIG. As shown in FIG. 1, the valve V11 is opened, and air outside the system is supplied to the catalytic combustion unit 14 via the four-way valve 21. Next, the valve V10 is opened to open the hydrogen storage tank 18 filled with the hydrogen storage alloy.
High-purity hydrogen from the catalytic combustion unit 14 via the four-way valve 21
To supply. By supplying air and hydrogen in this manner, a catalytic combustion reaction is performed in the catalytic combustion section 14. The combustion gas (exhaust gas) of the catalytic combustion unit 14 is heat-exchanged by the heat exchangers E1 and E2, and then discharged outside the system through the valve V13. The combustion reaction proceeds in the catalytic combustion section 14 and the temperature of the steam reforming section 13 (380 to 800 ° C.)
Is stable, the valve V3 is opened, and the water pumped from the supply pump P becomes steam by the heat exchanger E2,
It is supplied to the steam reforming section 13. Then, valve V2
Is opened, hydrogen for desulfurization is supplied from the hydrogen storage tank 18 to the hydrodesulfurization unit 12, and similarly, V1 is opened to supply city gas (raw material hydrocarbon) to the hydrodesulfurization unit 12, and the compressor 1
Start 1 As a result, the hydrogen for hydrodesulfurization from the hydrogen storage tank 18 is supplied to the hydrodesulfurization unit 12 by the compressor 11.
Is added to the city gas supplied to the city. Thereafter, the city gas and the hydrogen for hydrodesulfurization are heat-exchanged by the heat exchanger E1, and heated and heated to 300 to 400 ° C.

While gradually supplying the city gas to the hydrodesulfurization unit 12, the reforming reaction in the steam reforming unit 13 is started to produce a high-concentration hydrogen-containing gas. The high-concentration hydrogen-containing gas is supplied to the gas shift section 15, and carbon monoxide in the gas is converted into carbon dioxide and hydrogen by the shift catalyst.
The high-concentration hydrogen-containing gas gas-converted in the gas conversion unit 15 is cooled in the heat exchanger E3, and the water contained in the gas is condensed and removed by the KO drum 16. The valve V16 is opened to bypass the PSA section 17 until the hydrogen content of the high-concentration hydrogen-containing gas from which water has been removed is stabilized, and a part or all of the gas is stored in the off-gas holder 20. Next, the stored hydrogen-containing gas is heated by the heat exchanger E3, and is supplied to the catalytic combustion unit 14 via the four-way valve 21 and burned while opening the valve V9. in this way,
PSA unit 1 until high-concentration hydrogen-containing gas becomes stable at startup
The reason for bypassing 7 is to optimize the operation in the PSA unit 17 and to stabilize high-purity hydrogen adsorbed and separated from the PSA unit 17.

Then, after the high-concentration hydrogen-containing gas after the gas conversion is stabilized, the valves V4, V5, and V6 are opened and PS
The operation of the A section 17 is started. Of these, valves V4 and V
5, the high-concentration hydrogen-containing gas after gas conversion passes through the heat exchanger E3 and the KO drum 16, and the PSA unit 1
7 from the high-concentration hydrogen-containing gas.
The high-purity hydrogen not adsorbed by the adsorbent No. 7 is purified and separated and stored in the hydrogen storage tank 18. On the other hand, valve V6
, The methane removed in the PSA section 17,
Off-gases such as carbon monoxide, carbon dioxide, water vapor, and hydrogen pass through the off-gas holder 20, the heat exchanger E3, the valve V9, and the four-way valve 21 and are supplied to the catalytic combustion unit 14.

The inside of the hydrodesulfurization section 12 and the steam reforming section 13
When the reaction in the reactor is stabilized and high-purity hydrogen is stably purified and separated in the PSA section 17, the valve V7,
V8 and V12 are opened, and the valve V16 is closed. Thus, high-purity hydrogen is supplied from the hydrogen storage tank 18 to the fuel cell 19 via the valve V7. On the other hand, valve V
Air outside the system is supplied to the fuel cell 19 via the power supply 12. As a result, an ionic reaction occurs in the fuel cell 19, and electric energy can be extracted to the outside. Further, excess high-purity hydrogen from the fuel cell 19 is supplied from the fuel cell 19 to the catalytic combustion unit 14 through the off-gas holder 20, the heat exchanger E3, the valve V9, and the four-way valve 21 via the valve V8. Then, by closing the valve V10, the supply of high-purity hydrogen from the hydrogen storage tank 18 to the catalytic combustion unit 14 is stopped.

When the system is started, by adopting the catalytic combustion method in this manner, high-purity hydrogen previously stored in the hydrogen storage tank 18 is simply supplied to the catalytic combustion section 14 so that the system can be easily operated. Each reaction of hydrogen production can be started. Similarly, hydrogen for hydrodesulfurization can be supplied from the hydrogen storage tank 18. This eliminates the need for a conventional hydrogen cylinder for desulfurization and a nitrogen cylinder for start-up. As a result, it is possible to obtain effects such as a reduction in the installation area of the cylinder and a reduction in the operation cost, and further, the need to replace the cylinder. Also, P
By using a part of the high-purity hydrogen purified and separated in the SA unit 17 as hydrogen for hydrodesulfurization, the desulfurization efficiency is increased, the life of the steam reforming catalyst is extended, and the fuel cell 19 has high purity with few impurities. Since hydrogen can be supplied, deterioration of battery performance due to poisoning of the electrode with carbon monoxide can be prevented. Note that the valve 14 in the figure is always closed at the time of the start-up and the operation.

Next, the operation at the time of stop will be described with reference to FIG. As shown in FIG. 2, first, the valves V7, V8, V
12, the supply of high-purity hydrogen from the hydrogen storage tank 18 to the fuel cell 19 and the supply of air from outside the system are stopped, and the ion reaction inside the fuel cell 19 is stopped. Next, the valves V4, V5, and V6 are closed, and the PSA unit 17 is stopped. The reformed gas (high-concentration hydrogen-containing gas) from which gas has been converted and moisture has been removed bypasses the PSA unit 17 and passes through the valve V16, the off-gas holder 20, the heat exchanger E3, and the valve V
The fuel is supplied to the catalytic combustion section 14 through the 9- and 4-way valves 21 and burned. Next, by adjusting the valve V11, the supply amount of air from outside the system is gradually reduced, and the oxygen concentration in the combustion gas from the catalytic combustion unit 14 is reduced to zero. At this time, the valve V10 and, if necessary, the valve V15 are adjusted to prevent high-purity hydrogen in the hydrogen storage tank 18 and the city Gas may be supplied to the catalytic combustion section 14 as auxiliary fuel. Such an adjustment of the oxygen concentration is necessary when the amount of air supplied to the catalytic combustion unit 14 is gradually reduced. For example, when the amount of air is insufficient, the oxygen Is mixed into the steam reforming unit 1
This is for eliminating the possibility that oxygen is contained in the system such as 3. Subsequently, by adjusting the valve V1, the valve V14 is opened while gradually reducing the supply amount of the city gas, and the combustion gas from the catalytic combustion unit 14 is gradually supplied to the reaction system by the compressor 11 and circulated. . At this time, the valve V13, which is an exhaust valve for the combustion gas, is closed to stop the exhaust of the combustion gas.

By adjusting the valves V2 and V3, the supply of hydrogen for desulfurization from the hydrogen storage tank 18 to the system and the supply of steam to the system by the supply pump P are gradually reduced. In the reaction system (hydrodesulfurization unit 12,
Steam reforming section 13, catalytic combustion section 14, gas conversion section 15)
Reduce the concentration of flammable gas. Finally, the valve V1
And shut off the city gas supply. Further, the valves V2 and V3 are closed, and if necessary, the valve V
10, V15 is closed to stop the supply of hydrogen for hydrodesulfurization, the supply of steam, and the supply of auxiliary fuel to the catalytic combustion section.
Then, the valve V10 is closed (if necessary, the valve V15 is also closed), and the supply of the auxiliary fuel to the catalytic combustion unit 14 is stopped. Subsequently, the combustible gas in the system is completely replaced with nitrogen, carbon dioxide, and steam, and the valve V11 is closed to stop the supply of air to the catalytic combustion unit 14. Further, when the temperature in the system (steam reforming section 13) decreases to 100 ° C. or less, the compressor 11 is stopped, and all operations are stopped. In addition, the temperature at the time of the stop is preferably lowered to room temperature because water in the system can be removed. When it is necessary to purge the gas in the system, the valve V13 is opened, and when the barge is completed, all the valves V1 to V1 are opened.
6 is closed. At this time, if all the valves V1 to V16 are closed while maintaining the pressure in the system, air does not flow into the system from outside during stoppage. As a result, oxidation of the catalyst can be prevented at the next start operation.

As described above, when the system is stopped, the combustion gas (exhaust gas) containing no oxygen is recycled into the reaction system while gradually lowering the concentration of the flammable gas. Thereby, it is finally converted into nitrogen, carbon dioxide, and water vapor and stopped. As a result, the activity of each catalyst is reduced, especially in the case of ruthenium-based catalysts, etc., which prevents oxidation of catalysts that have problems such as high toxicity at high temperatures, and eliminates the need for replacement cylinders. Become. Also, in this catalytic combustion method, the oxidation reaction can be performed even at a low concentration,
When the concentration of the combustible gas is gradually reduced during the stop operation, incomplete combustion can be prevented and the combustion reaction can be continued.

[0033]

According to the present invention, the hydrogen production apparatus can be started / stopped without using a nitrogen cylinder and a hydrogen cylinder, so that the operation cost and installation area can be reduced, and dangerous nitrogen and hydrogen cylinder replacement can be performed. The effect that work becomes unnecessary can be obtained. In addition, the start / stop operation can be automated by forming a sequence. Since the temperature of the steam reforming section is raised by the catalytic combustion method, it is possible to obtain effects such as downsizing of the apparatus and reduction of NOx. Also,
A gas conversion unit and a PSA unit are adopted as the high-purity hydrogen purification unit, and high-purity hydrogen with few impurities is supplied to the polymer electrolyte fuel cell, so that the electrode is less poisoned and the performance of the cell is prevented from deteriorating. it can. Further, it is possible to cope with a case where a cylinder cannot be placed in a hydrogen production apparatus for a vehicle-mounted or household fuel cell.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a starting method of a hydrogen production apparatus according to one embodiment of the present invention.

FIG. 2 is a system diagram showing a method for stopping the hydrogen production apparatus according to one embodiment of the present invention.

[Description of Signs] 10 Hydrogen production apparatus 11 Compressor 12 Hydrodesulfurization section (desulfurization section) 13 Steam reforming section 14 Catalytic combustion section 15 Gas shift section 17 PSA section 18 Hydrogen storage tank (Hydrogen storage section) 19 Solid polymer Type fuel cell (fuel cell) 20 Off-gas holder (Off-gas storage unit)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 8/04 H01M 8/04 XY J 8/06 8/06 G 8/10 8/10

Claims (9)

[Claims] 1. A desulfurization unit for removing a sulfur content of a raw hydrocarbon, a steam reforming unit for generating a hydrogen-containing gas by adding steam to the raw hydrocarbon desulfurized in the desulfurization unit and performing steam reforming. A gas conversion unit for converting carbon monoxide in the hydrogen-containing gas into carbon dioxide and hydrogen; a PSA unit for purifying the hydrogen-containing gas gas-converted in the gas conversion unit to high-purity hydrogen; A combustion reaction between the reactive gas and oxygen in the air, and a start-up method for a hydrogen production apparatus including a catalytic combustion unit that heats the steam reforming unit. When the temperature of the steam reforming section reaches the temperature at which steam reforming starts, the steam and the raw material hydrocarbon are supplied. Starting hydrogen production equipment How to start. 2. The hydrogen-containing gas bypasses the PSA section and is supplied to the catalytic combustion section for combustion until the hydrogen content of the hydrogen-containing gas after the gas conversion is stabilized, so that the hydrogen-containing gas is stabilized. The method for starting a hydrogen production apparatus according to claim 1, wherein the supply to the PSA section is started after that, and the PSA section is refined to high-purity hydrogen. 3. The method according to claim 1, wherein the high-purity hydrogen is supplied to a fuel cell. 4. The hydrodesulfurization unit according to claim 1, wherein the desulfurization unit is configured to add hydrogen for hydrodesulfurization to the raw material hydrocarbons, and then desulfurize and remove sulfur in the raw material hydrocarbons. 3
The method for starting a hydrogen production apparatus according to any one of the preceding claims. 5. The method for starting a hydrogen production apparatus according to claim 1, further comprising a hydrogen storage unit for storing high-purity hydrogen obtained from the PSA unit. 6. The method according to claim 5, wherein the high-purity hydrogen in the hydrogen storage unit is supplied to the hydrodesulfurization unit as hydrogen for hydrodesulfurization. 7. A desulfurization unit for removing a sulfur content of a raw hydrocarbon, a steam reforming unit for generating a hydrogen-containing gas by adding steam to the raw hydrocarbon desulfurized in the desulfurization unit and performing steam reforming. A gas conversion unit for converting carbon monoxide in the hydrogen-containing gas into carbon dioxide and hydrogen; a PSA unit for purifying the hydrogen-containing gas gas-converted in the gas conversion unit to high-purity hydrogen; A method for stopping a hydrogen production apparatus including a catalytic combustion section that heats the steam reforming section by causing a combustion reaction between the reactive gas and oxygen in the air, wherein the PSA section is stopped, and the hydrogen after gas conversion is stopped. The contained gas bypasses the PSA section and is supplied to the catalytic combustion section for combustion. The supply amount of air to the catalytic combustion section is gradually reduced, and the oxygen concentration in the combustion gas discharged from the catalytic combustion section is reduced. Reduce the catalytic combustion The combustion gas from the reactor is supplied to the reaction system of the hydrogen production apparatus, and while the supply amounts of the raw material hydrocarbon and steam are gradually reduced, the concentration of the combustible gas in the reaction system is reduced. A method for stopping the hydrogen production apparatus, wherein the supply of air to the section is stopped and the hydrogen production apparatus is stopped after the temperature in the reaction system has dropped. 8. The method according to claim 7, wherein the high-purity hydrogen is supplied to a fuel cell. 9. The hydrodesulfurization unit according to claim 7, wherein the desulfurization unit is configured to add hydrogen for hydrodesulfurization to the raw material hydrocarbon, and then desulfurize and remove the sulfur content in the raw material hydrocarbon. 9. The method for shutting down a hydrogen production apparatus according to item 8.