JP2004338975A - Starting method of hydrogen production apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a starting method of a hydrogen production apparatus that accelerates the rapid starting and further enhances the high reforming efficiency, and that the downsizing of the apparatus is possible. <P>SOLUTION: The method comprises elevating a temperature of a reforming part 13 by causing an oxidation reaction by supplying a town gas 13A and air to the reforming part 13, then gradually supplying steam while gradually reducing the amount to be supplied of air to the reforming part 13 and finally terminating the supply of air, whereas only steam is supplied to the reforming part 13 and the step is transferred to the steam reforming reaction. Thereby, the rapid starting is accelerated and further the high reforming efficiency is realized as well as the apparatus can be compacted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for starting a hydrogen production apparatus, specifically, a temperature rise (partial oxidation reforming) by introducing and burning a raw material hydrocarbon and air in a reforming section, and then sequentially converting air to steam. The present invention relates to a method for starting a hydrogen production apparatus capable of achieving quick start-up and high reforming efficiency by shifting to autothermal reforming and finally to steam reforming with the amount of introduced air being zero.
[0002]
[Prior art]
For example, as a method for supplying hydrogen to a fuel cell, a fuel reformer that generates a hydrogen-containing gas by a reforming reaction using a catalyst of a hydrocarbon-based fuel gas such as methanol or natural gas has been developed.
When starting the hydrogen production apparatus, it is necessary to raise the inlet temperature of the reforming section to 400 ° C. or higher. Therefore, according to the conventional steam reforming, for example, when methane is used as an example, the reaction is performed at a high temperature of 750 to 800 ° C. At the time of startup, an inert gas such as nitrogen filled in each cylinder was used. That is, at the time of this startup, the temperature is raised by a burner or the like while flowing nitrogen from the nitrogen cylinder into the system. Therefore, there is a problem that a nitrogen cylinder is required, resulting in an increase in cost and an increase in installation space. Further, when the inert gas was exhausted, the starting operation could not be performed, and replacement of the cylinder was troublesome. In addition, it may be impossible to install a nitrogen cylinder due to small devices (for example, hydrogen production devices used for fuel cells for homes and automobiles) and various other circumstances. There were also problems. Furthermore, steam reforming is a relatively large endothermic reaction. Therefore, it is necessary to install a heater and a burner in parallel with the reforming section, and it takes a long time to start. Also, the energy efficiency of the entire system has been reduced.
[0003]
Therefore, as a conventional technique for solving this, partial oxidation reforming accompanied by an exothermic reaction is known. This is because air (N ₂ / O ₂ ) as an oxidant is supplied to the reforming section by an air compressor, where the raw material hydrocarbon and air are mixed, and the raw material hydrocarbon is partially converted using a partial oxidation catalyst. It oxidizes and reforms raw material hydrocarbons.
However, partial oxidation reforming is an exothermic reaction, and although there is little external heating by a burner and the start-up time is very short, control is difficult due to the large amount of heat generated by oxidation, and soot generation is suppressed. Has issues. Further, oxygen is supplied as air by an air compressor, but nitrogen unnecessary for the reaction is also supplied. This leads to an increase in the size of the reforming section and an increase in the power of the compressor. In addition, the energy efficiency was poor from the amount of hydrogen generated with respect to the amount of fuel input.
[0004]
Autothermal reforming is known as a conventional technique for solving such problems of steam reforming and partial oxidation reforming. Autothermal reforming balances the heat balance of the heat of reaction between steam reforming and partial oxidation reforming, and uses the amount of heat released in the partial oxidation reaction to perform the reforming reaction of endothermic steam reforming. It is a method that is performed simultaneously. Auto thermal reforming has a shorter start-up time than steam reforming, and if the temperature of the reforming section is initially raised to the set temperature, heating of the reforming section by a burner is not required, and rapid reforming reaction There is no need to follow external heat supply or cooling in accordance with the increase or decrease of the temperature. For this reason, control is facilitated, and thus, it has been attracting attention in recent years.
[0005]
However, according to the autothermal reforming, although the startup time is shorter than that of the steam reforming involving an endothermic reaction, the startup is not as quick as that of the partial oxidation reforming involving an exothermic reaction.
In the autothermal reforming, as in the case of the partial oxidation reforming, air is introduced into the reforming section together with steam as an oxidizing agent. As a result, a large amount of nitrogen gas unnecessary for the reaction is supplied to the reforming section, and the off-gas obtained from the subsequent purification step cannot be effectively used, thereby lowering the reforming efficiency. In addition, there is a problem that the reforming section and the compressor become large.
[0006]
[Problems to be solved by the invention]
As a result of intensive research, the present inventors have found that at the time of start-up, first, air and a raw material hydrocarbon are introduced into a reforming section to perform an oxidation reaction, and thereafter, the air is gradually converted to steam to shift to auto thermal reforming. I do. Finally, it was found that if the amount of air introduced is finally reduced to zero and the process is completely shifted to steam reforming, startup can be speeded up, high reforming efficiency can be achieved, and the equipment can be made more compact. Thus, the present invention has been completed.
In other words, the present invention is based on such a conventional technique, and a start-up method of a hydrogen production apparatus capable of achieving quick start-up, high reforming efficiency, and downsizing of the apparatus. It is intended to provide.
[0007]
[Means for Solving the Problems]
The first aspect of the present invention provides a desulfurization unit for removing the sulfur content of a raw hydrocarbon, and a reforming unit for generating a hydrogen-containing gas by adding steam to the raw hydrocarbon desulfurized in the desulfurization unit to reform the raw hydrocarbon. And a gas conversion unit for converting carbon monoxide in the hydrogen-containing gas into carbon dioxide and hydrogen, and a PSA unit for purifying the hydrogen-containing gas gas-converted in the gas conversion unit to high-purity hydrogen. In the start-up method of the manufacturing apparatus, the raw material hydrocarbons and air are supplied to the reforming section to generate an oxidation reaction, thereby raising the temperature of the reforming section, and then reducing the amount of air supplied to the reforming section. This is a method for activating a hydrogen production apparatus in which steam is gradually supplied while gradually decreasing the supply of air, and finally the supply of air is stopped, while only the steam is supplied to the reforming section to shift to a steam reforming reaction.
[0008]
According to the second aspect of the present invention, hydrogen is introduced into the reforming section before or at the same time as the introduction of the raw material hydrocarbon into the reforming section, and a combustion reaction occurs between the hydrogen and oxygen in the air. The method for starting the hydrogen production apparatus described in the above.
[0009]
The invention according to claim 3 is a method in which air and hydrogen are introduced into the desulfurization section before or simultaneously with introduction of the raw material hydrocarbon into the reforming section, and a combustion reaction between the hydrogen and oxygen in the air is performed. 2. A method for starting a hydrogen production apparatus according to item 1.
[0010]
The invention according to claim 4 is to introduce air and hydrogen into the gas shift section before or simultaneously with the introduction of the raw material hydrocarbon into the reforming section, and to cause a combustion reaction between the hydrogen and oxygen in the air. A method for starting the hydrogen production apparatus according to claim 1.
[0011]
According to a fifth aspect of the present invention, there is provided a reforming furnace for causing a combustion reaction between a hydrogen-containing flammable gas and oxygen in the air to heat the reforming section from the outside. 2. The hydrogen according to claim 1, wherein hydrogen and / or raw material hydrocarbon is introduced into the reforming furnace before or at the same time as the introduction of hydrogen, and the hydrogen and / or raw material hydrocarbon and oxygen in the air undergo a combustion reaction. 3. This is a method for starting the manufacturing apparatus.
[0012]
The invention according to claim 6 is the method according to any one of claims 1 to 5, wherein the hydrogen is obtained from an accumulator or a hydrogen buffer tank that stores high-purity hydrogen purified by the PSA unit. This is a method for starting the hydrogen production apparatus.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a system diagram showing a method for starting a 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, the city gas 13A is adopted.
Hereinafter, each component of the hydrogen production apparatus 10 will be described. Reference numeral 11 denotes a compressor that supplies the city gas 13A to the desulfurization unit 12. The desulfurization unit 12 is divided into a hydrogenation catalyst layer on the upstream side and a desulfurization agent layer on the downstream side. In the desulfurization unit 12, a part of the high-purity hydrogen (purified hydrogen) that is pressure-adsorbed and separated from the city gas 13 </ b> A supplied by the compressor 11 in the PSA unit 17 described below and stored in the accumulator 18 is used for hydrodesulfurization. By adding as hydrogen, the sulfur content in the city gas 13A is desulfurized.
[0014]
Examples of the hydrogenation catalyst include a NiMox catalyst or a CoMox catalyst in which an oxide such as nickel-molybdenum or cobalt-molybdenum, or a sulfide is supported on a carrier such as silica or alumina. In addition, as the desulfurizing agent, zinc oxide, nickel-based sorbent, or the like is used alone or appropriately supported on a carrier. In the hydrogenation catalyst layer, the sulfur content 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. In addition, the raw material hydrocarbon after desulfurization is supplied to the reforming unit 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 may be used. Examples of the catalyst in this case include metals such as nickel, zinc, and copper, and oxides and sulfides thereof, as well as zeolite and activated carbon. As the activated carbon, those to which an alkali metal such as sodium is impregnated can be used.
[0015]
The reforming unit 13 produces a high-concentration hydrogen-containing gas by adding water or steam to the desulfurized city gas 13A, and further contacting the filled reforming catalyst to perform steam reforming. A reforming furnace 14 is provided around the reformer 13. A burner 14a for heating the reforming section 13 from the outside is provided below the reforming furnace 14. Examples of the reforming catalyst include one 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 high carbon number is used, because carbon deposition can be suppressed. In the reforming section 13, steam reforming of the desulfurized hydrocarbon is performed. The reaction here is shown below.
C _m H _n + mH ₂ O → mCO + (m + n / 2) H ₂ (1)
CO + 3H ₂ ← → CH ₄ + H ₂ O (2)
CO + H ₂ O ← → CO ₂ + H ₂ (3)
[0016]
Air is supplied to the reforming unit 13 at the time of startup as an oxidizing agent via an air compressor (not shown). In this way, the air is supplied to the reforming unit 13, the city gas 13A desulfurized and the air are mixed, and the city gas 13A is oxidized using a catalyst. The reforming catalyst also serves as an oxidation catalyst.
When the city gas 13A passes through the reforming section 13 maintained at a high operating temperature of 400 ° C. or higher, a combustion reaction shown in the following (4) is caused.
CH ₄ + 2O ₂ → CO ₂ + 2H ₂ O (4)
During startup, the reformer 13 is heated and heated by the burner 14a. However, the operating temperature (500 to 700 ° C.) can be maintained by the heat generated by the catalytic oxidation.
[0017]
Autothermal reforming balances the heat of reaction between steam reforming and partial oxidation reforming, and converts city gas 13A into oxygen, steam in air, and carbon monoxide and hydrogen in the presence of a catalyst for autothermal reforming. Refers to a reaction for converting into a reformed gas containing.
This reaction includes a partial oxidation reaction for oxidizing a part of the city gas 13A and a steam reforming reaction. The reforming catalyst also serves as an autothermal reforming catalyst. The temperature at which the oxidation reaction state shifts to autothermal reforming is preferably from 400 to 700C, particularly preferably from 500 to 600C. If the temperature is lower than 400 ° C., there is a disadvantage that the reaction does not proceed sufficiently. On the other hand, when the temperature exceeds 700 ° C., there is a disadvantage that deterioration due to sintering of the catalyst becomes large. The transition time from the oxidation reaction state to the autothermal reforming is usually 5 to 30 minutes, preferably 10 to 20 minutes, though it depends on the temperature rise in the system. If the time is less than 5 minutes, there is a disadvantage that the temperature in the system is not uniform. On the other hand, if the time exceeds 30 minutes, there is a disadvantage that useless waiting time increases.
[0018]
Specific examples of the raw material hydrocarbon include saturated aliphatic hydrocarbons such as methane, ethane, propane, butane, pentane, hexane, cyclopentane, cyclohexane and dodecane, and unsaturated aliphatic hydrocarbons such as ethylene, propylene and butene. be able to. Also, a mixture of these can be suitably used, and examples thereof include materials which are industrially available at low cost, such as natural gas, LPG, naphtha, gasoline, kerosene, and light oil. Specific examples of the hydrocarbon compounds having a substituent containing a hetero atom include methanol, ethanol, propanol, butanol, dimethyl ether, phenol, anisole, acetaldehyde, acetic acid, acetamide, triethylamine and the like.
[0019]
Since the sulfur concentration in the city gas 13A has an effect of inactivating the reforming catalyst, it is desirable that the sulfur concentration be as low as possible by desulfurization by the desulfurization unit 12. Preferably it is 1 mass ppm or less, more preferably 0.05 mass ppm or less.
The amount of air supplied at the time of the autothermal reforming is usually an amount capable of generating an amount of heat capable of balancing the endothermic reaction of the steam reforming. However, the amount of addition is determined appropriately in relation to heat loss and external heating provided as needed. The amount thereof is preferably 0.05 to 1, more preferably 0.1 to 0.75, more preferably 0.1 to 0.75, as the ratio of the number of moles of oxygen molecules to the number of moles of carbon atoms contained in the city gas 13A. 0.2 to 0.6. When the oxygen / carbon ratio is less than 0.05, heat generation is small, and a large amount of heat needs to be supplied from the outside using the burner 14a. On the other hand, when the oxygen / carbon ratio exceeds 1, heat generation becomes too large, and it becomes difficult to maintain a heat balance.
[0020]
Oxygen may be pure oxygen, but those diluted with other gases can also be suitably used, and may include water vapor, carbon dioxide, carbon monoxide, argon, nitrogen, etc. Air is preferably used as a gas containing oxygen.
The method for adding oxygen to the city gas 13A is not limited. For example, the city gas 13A may be introduced into the reaction region at the same time. Further, the oxygen-containing gas and the city gas 13A may be supplied from different positions in the reaction region. Further, it may be introduced in several parts.
[0021]
The amount of water vapor introduced into the reaction system is defined as the ratio of the number of moles of water molecules to the number of moles of carbon atoms contained in the city gas 13A (steam / carbon ratio), and this value is preferably 0.3 to 10, more preferably Is 0.5 to 5, more preferably 1 to 3. If it is less than 0.3, coke tends to precipitate on the catalyst, and the obtained hydrogen fraction tends to decrease. On the other hand, if it exceeds 10, the reforming reaction proceeds, but the steam generating equipment and the steam recovery equipment may be enlarged. The method for adding steam to the city gas 13A is not limited. For example, the city gas 13A may be introduced into the reaction region at the same time, or may be introduced from a different position in the reaction region or by dividing it into several portions.
[0022]
Reference numeral 15 denotes a gas shift unit filled with a shift catalyst for converting carbon monoxide in the high-concentration hydrogen-containing gas produced in the reforming unit 13 into carbon dioxide and hydrogen. The shift catalyst, iron - chromium _{(e.g., 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 in the case of Fe _{2 O 3 -Cr 2} O 3 catalyst, 300 to 450 ° C., for a copper-based catalyst preferably up to 200 to 250 ° C.. The reaction here is CO + H ₂ O = CO ₂ + H ₂ .
[0023]
Reference numeral 16 denotes a KO (knock-out) drum that cools the high-concentration hydrogen-containing gas that has been gas-converted in the gas conversion unit 15 and condenses and removes moisture contained in the gas. Reference numeral 17 denotes a PSA (Pressure Swing Absorption) section for pressure-adsorbing and separating high-purity hydrogen from a gas-converted high-concentration hydrogen-containing gas from which water vapor has been removed. 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 purified by passing high-purity hydrogen. Reference numeral 18 denotes an accumulator that stores the high-purity hydrogen purified by the PSA unit 17. The accumulator 18 is capable of storing the required amount of hydrogen for catalytic combustion and hydrogenation gas at the time of start-up. In order to achieve compactness, a tank filled with a hydrogen storage alloy may be used.
[0024]
Reference numeral 19 denotes a dispenser for supplying high-purity hydrogen temporarily stored in the accumulator 18 as hydrogen for a fuel cell of an automobile. The high-purity hydrogen from which impurities have been removed by the PSA unit 17 is supplied to a fuel cell vehicle via a dispenser 19, where electric energy is obtained while generating water. The impurities in the high-purity hydrogen purified and separated in the PSA section 17 are 10 ppm or less. This eliminates the risk that the electrodes of the polymer electrolyte fuel cell mounted on the vehicle will be poisoned by carbon monoxide and the cell performance will decrease. 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.
[0025]
A polymer electrolyte fuel cell 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 ⁻ (5)
1 / 2O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O (6)
(Total reaction) H ₂ + 1 / 2O ₂ → H ₂ O (7)
The hydrogen ions generated by the formula (5) move together with water (xH ₂ O) via the ion exchange group in the polymer ion exchange membrane, and react with oxygen as shown in the formula (6) to form water (H). ₂ O).
[0026]
Reference numeral 20 denotes an off-gas holder (off-gas storage unit) in which the off-gas adsorbed and removed by the PSA unit 17 is temporarily stored, and is supplied to the reforming furnace 14 as fuel for heating the reforming unit 13. In addition, the high-concentration hydrogen-containing gas after gas conversion from which moisture has been removed by the KO drum 16 at startup is supplied to the off-gas holder 20, bypassing the PSA unit 17.
[0027]
The symbol E1 heat-exchanges the city gas 13A supplied from the compressor 11 to the desulfurization unit 12 and the combustion gas from the reforming furnace 14 to raise the city gas 13A to a hydrodesulfurization temperature of 300 to 400 ° C. It is a heat exchanger. Symbol E2 is a heat exchanger that exchanges heat between water supplied to the reforming section 13 by the supply pump P and combustion gas from the reforming furnace 14 to generate steam for steam reforming. Symbol E3 is a cooler for cooling.
[0028]
Here, the hydrogen production apparatus 10 includes a compressor 11, a desulfurization unit 12, a reforming unit 13, a reforming furnace 14, a gas conversion unit 15, a PSA unit 17, and an accumulator (may be a hydrogen buffer tank) 18. Have been. However, it is not always necessary to provide the gas shift section 15 downstream of the reforming section 13. However, it is preferable to provide the gas shift section 15. This is because the amount of hydrogen increases and the amount of carbon monoxide can be reduced, and the adsorption and separation of high-purity hydrogen in the PSA unit 17 is performed at a relatively low temperature of normal temperature. This is because it is preferable. In the figure, reference numeral 21 denotes a four-way valve type flow switching device (hereinafter, referred to as a four-way valve).
[0029]
A method for starting the hydrogen production apparatus 10 having the above configuration will be described in detail below.
As shown in FIG. 1, the valves V11 and V15 are opened, and air outside the system is supplied to the burner 14a via the four-way valve 21 by an air compressor (not shown) and to the reforming unit 13. As described above, air is supplied to the reforming unit 13 at the time of startup as an oxidizing agent. On the other hand, the city gas 13A is also supplied to the burner 14a via the four-way valve 21. Further, the valve V2 is opened to introduce hydrogen into the system. Therefore, in the reforming unit 13, the hydrogen and / or the city gas 13A and the air are mixed, and the hydrogen and / or the city gas 13A is oxidized by the oxidation catalyst which also serves as the reforming catalyst.
At this time, the burner is heated in the reforming furnace 14 by supplying the air and the city gas 13A to the burner 14a.
[0030]
Thereafter, when the temperature of the reforming section 13 reaches about 400 ° C., the state shifts from the oxidation reaction state to autothermal reforming. That is, while the valve V15 is gradually closed to gradually reduce the amount of air supplied to the reforming section 13, the valve V3 is gradually opened to gradually supply steam to the reforming section 13. The water vapor is obtained by being heated by the water pumped from the supply pump P passing through the heat exchanger E2. The transition time from the oxidation reaction state to the autothermal reforming is 10 to 20 minutes.
In the autothermal reforming, the city gas 13A is converted into a reformed gas containing carbon monoxide and hydrogen in the presence of oxygen, steam in the air and a catalyst for autothermal reforming, and the reaction between steam reforming and the oxidation reaction is performed. Balance the heat balance. The reforming catalyst also serves as the catalyst for autothermal reforming, similarly to the catalyst for partial oxidation reforming.
Then, when the combustion reaction in the reforming section 13 proceeds and the temperature of the reforming section 13 is finally stabilized at 400 to 700 ° C., the valve V15 is fully closed and the valve V3 is fully opened to perform auto thermal reforming. Move from quality to steam reforming.
[0031]
The combustion gas (exhaust gas) from the reforming furnace 14 is heat-exchanged by the heat exchangers E1 and E2, and then discharged out of the system through the valve V13. Thereby, after the inside of the system is stabilized, hydrogen from the valve V2 is controlled to an amount required for hydrodesulfurization, and is added to the city gas 13A supplied to the desulfurization unit 12 by the compressor 11. Thereafter, the city gas 13A and the hydrogen for hydrodesulfurization are heat-exchanged by the heat exchanger E1, and are heated and heated to 300 to 400 ° C.
[0032]
While gradually supplying the city gas 13A to the desulfurization unit 12, the reforming reaction in the reforming unit 13 is started to produce a high-concentration hydrogen-containing gas. This 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. Until the hydrogen content of the high-concentration hydrogen-containing gas from which water has been removed is stabilized, the valve V16 is opened to bypass the PSA section 17, and a part or all of the gas is stored in the off-gas holder 20. Next, the stored hydrogen-containing gas is supplied to the reforming furnace 14 via the four-way valve 21 and burned by opening the valve V9. The reason why the PSA unit 17 is bypassed until the high-concentration hydrogen-containing gas becomes stable at the time of startup is to optimize the operation of the PSA unit 17 and stabilize the high-purity hydrogen adsorbed and separated from the PSA unit 17. It is to make it.
[0033]
After that, after the high-concentration hydrogen-containing gas after the gas conversion is stabilized, the valves V4, V5, and V6 are opened, and the operation of the PSA unit 17 is started. By opening the valves V4 and V5, the high-concentration hydrogen-containing gas after gas conversion is supplied to the PSA section 17 through the heat exchanger E3 and the KO drum 16, and the high-concentration hydrogen-containing gas is High-purity hydrogen not adsorbed by the adsorbent of the PSA unit 17 is purified and separated, and stored in the pressure accumulator 18. On the other hand, when the valve V6 is opened, the off-gas such as methane, carbon monoxide, carbon dioxide, water vapor, and hydrogen removed in the PSA unit 17 is supplied to the off-gas holder 20, the heat exchanger E3, the valve V9, and the four-way valve 21. And is supplied to the reforming furnace 14.
When the reaction in the desulfurization section 12 and the reforming section 13 is stabilized and high-purity hydrogen is stably purified and separated in the PSA section 17, the valve V7 is opened and the valve V16 is closed. In this way, high-purity hydrogen is supplied from the accumulator 18 to the fuel cell of the vehicle through the dispenser 19 via the valve V7.
[0034]
As described above, at the time of starting the system, first, the air and the city gas 13A are introduced into the reforming unit 13 to perform an oxidation reaction, and thereafter, the air is gradually converted into water vapor to shift to auto thermal reforming. In this case, the amount of air introduced is reduced to zero, and the process is completely shifted to steam reforming. Therefore, the start-up can be speeded up, high reforming efficiency can be achieved, and the apparatus can be downsized.
[0035]
Further, before or simultaneously with the introduction of the city gas 13A into the reforming unit 13, hydrogen may be introduced into the reforming unit 13 to cause a combustion reaction between the hydrogen and oxygen in the air. Further, before or simultaneously with the introduction of the city gas 13A into the reforming unit 13, air and hydrogen may be introduced into the desulfurization unit 12 to cause a combustion reaction between hydrogen and oxygen in the air. Furthermore, before or at the same time as the introduction of the city gas 13A into the reforming unit 13, air and hydrogen may be introduced into the gas conversion unit 15 to cause a combustion reaction between hydrogen and oxygen in the air. Then, before or simultaneously with the introduction of the city gas 13A to the reforming unit 13, the hydrogen and / or the city gas 13A is introduced into the reforming furnace 14, and the hydrogen and / or the city gas 13A and the oxygen in the air are burned. You may make it react.
[0036]
【The invention's effect】
In the present invention, at the time of start-up, first, air and a raw material hydrocarbon are introduced into a reforming section to perform an oxidation reaction, and thereafter, the air is gradually converted into steam to shift to autothermal reforming. Finally, the amount of air introduced was reduced to zero, and the process was completely shifted to steam reforming, so that start-up could be speeded up, high reforming efficiency could be achieved, and the equipment could be made more compact. Can be.
[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.
[Explanation of symbols]
10 Hydrogen production device 12 Desulfurization unit 13 Reforming unit 13A City gas (raw hydrocarbon)
14 Reforming furnace 15 Gas conversion unit 17 PSA unit 18 Pressure accumulator

Claims (6)

A desulfurization unit for removing the sulfur content of the raw hydrocarbons,
A reforming unit that generates a hydrogen-containing gas by adding steam to the raw material hydrocarbon desulfurized in the desulfurizing unit and reforming the steam;
A gas conversion unit that converts 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;
The raw material hydrocarbons and air are supplied to the reforming section to generate an oxidation reaction, thereby raising the temperature of the reforming section. Thereafter, while gradually reducing the amount of air supplied to the reforming section, steam is generated. A method for starting a hydrogen production apparatus in which the supply of air is stopped gradually while the supply of air is finally stopped, and only the steam is supplied to the reformer to shift to a steam reforming reaction. 2. The start-up of the hydrogen production apparatus according to claim 1, wherein hydrogen is introduced into the reforming section before or at the same time as the introduction of the raw material hydrocarbon into the reforming section, and the hydrogen and oxygen in the air undergo a combustion reaction. Method. 2. The hydrogen production apparatus according to claim 1, wherein air and hydrogen are introduced into the desulfurization section before or at the same time as the introduction of the raw material hydrocarbon into the reforming section, and the hydrogen and oxygen in the air undergo a combustion reaction. 3. How to start. 2. The hydrogen production according to claim 1, wherein air and hydrogen are introduced into the gas shift section before or at the same time as the introduction of the raw material hydrocarbons into the reforming section, and the hydrogen and oxygen in the air undergo a combustion reaction. How to start the device. Combustion reaction between the hydrogen-containing flammable gas and oxygen in the air, having a reforming furnace for heating the reforming unit from outside,
Before or simultaneously with the introduction of the raw material hydrocarbon into the reforming section, hydrogen and / or the raw material hydrocarbon are introduced into the reforming furnace, and the hydrogen and / or the raw material hydrocarbon and oxygen in the air are subjected to a combustion reaction. The method for starting a hydrogen production apparatus according to claim 1. The method according to any one of claims 1 to 5, wherein the hydrogen is obtained from an accumulator or a hydrogen buffer tank that stores high-purity hydrogen purified by the PSA unit.

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