JPH09227103A - Apparatus for producing hydrogen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wholly small-sized and lightweight apparatus for produc ing hydrogen capable of producing the high purity hydrogen at a high efficiency by using a plate reformer. SOLUTION: This apparatus for producing hydrogen is equipped with a plate reformer 12 composed of alternately laminated platy reforming chambers and combustion chambers, a hydrogen purifier 14 capable of adsorbing an excessive gas other than the hydrogen under a high pressure, desorbing the adsorbed excessive gas under a low pressure and purifying the hydrogen and an excessive gas circulating line 16 for introducing the excessive gas 13 separated in the hydrogen purifier 14 into the plate reformer 12. A hydrocarbon 2 is reformed with steam in the plate reformer 12 by using the heat of combustion of the excessive gas 13 to produce a reformed gas 4 containing the hydrogen 9, which is then separated and purified from the reformed gas 4 with the hydrogen purifier 14. A plate type shift converter 18 is further installed therein to make the reformed gas 4 flow through a reactional chamber and low temperature air is made to flow through an air chamber. The reactional chamber temperature is cooled to a temperature suitable for a shift reaction with the air flow rate. The heated air is then used for burning in the plate reformer 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogen production apparatus, and more particularly, it is a small-sized and high-efficiency apparatus that uses a plate-type device for downsizing and uses surplus gas from a hydrogen separation apparatus to improve efficiency. Related to hydrogen production equipment.

[0002]

2. Description of the Related Art Demand fields for hydrogen cover various fields such as weak electricity, oleochemistry, glass manufacturing, and metal manufacturing, and in recent years, the demand has been increasing more and more from the standpoint of prevention of global warming. on the other hand,
The hydrogen supply source has hitherto mainly been the electrolytic soda industry, and is inexpensively manufactured as a by-product of the electrolytic soda industry. However, since the hydrogen produced is compressed and filled in a pressure vessel and supplied to the demand destination, in recent years, transportation costs have increased significantly due to an increase in the transportation distance from the supply source to the demand destination and deterioration of traffic conditions. There is. Therefore, in place of cheap hydrogen as a by-product, there is a strong demand in the industry for a hydrogen production device that can obtain high-purity hydrogen inexpensively and safely from city gas or the like at the demand destination.

As an apparatus for producing hydrogen from city gas or the like, a tubular reformer for a plant is widely known.
35778, Japanese Patent Publication No. 5-9362, JP-A-62-2
No. 7303 has already been proposed for fuel cells.
However, these tubular type reformers have a problem that they are very large in size because they have a small heat transfer area per volume and require a large pressure vessel.

On the other hand, a plate reformer having a completely different structure from the above-mentioned conventional tubular reformer has already been proposed by the applicant of the present application and used in part. As shown in the principle diagram of FIG. 6, this plate reformer is configured by forming reforming chambers Re and combustion chambers Co in a flat plate shape and alternately stacking the reforming chambers Re and combustion chambers Co. -Shaped combustion catalyst 5 is filled in a flat plate shape, and fuel gas 1 and combustion air 7 supplied from external manifolds 6a and 6b flow as shown by a broken line in the figure, and react (combustion) by the action of combustion catalyst 5. ) And heat is generated, and the combustion exhaust gas 8 is on the opposite side of the external manifold 6
discharged from c. On the other hand, the reforming chamber Re is similarly filled with the particulate reforming catalyst 3 in a flat plate shape, and the raw material gas 2 supplied from the external manifold 6d flows as shown by the solid line in the figure, and the reforming catalyst 3 Reforms the source gas 2 by the action of
The reformed gas 4 is discharged from the external manifold 6e on the opposite side.

Compared with a tubular reformer, this plate reformer has a large heat transfer area per volume and can be made extremely small and lightweight, so that it is not only for fuel cells but also for other fields. Application to (for example, hydrogen production) is desired. The present invention meets such a demand and aims to provide a small-sized and lightweight hydrogen production apparatus using a plate reformer.

[0006]

When hydrogen is produced using a plate reformer, the reformed gas discharged from the reformer contains a large amount of impurities (CO, methane, etc.) other than hydrogen. ing. Therefore, in order to produce high-purity hydrogen, there is a problem that these impurities must be separated and removed with high precision.

Further, if the separated and removed impurities are directly discharged into the atmosphere, it not only causes air pollution, but also causes a large decrease in efficiency of the apparatus. Therefore, it is necessary to reduce impurities as much as possible and effectively use them. Further, even if the reformer itself is small and lightweight, the entire device tends to be large due to a combination with other devices (for example, a heat exchanger), piping between the devices, and heat retention of each part. Therefore, it is necessary to efficiently carry out these steps and reduce the size and weight as a whole.

The present invention has been made to solve such a problem. That is, an object of the present invention is to provide a hydrogen production apparatus which can produce high-purity hydrogen with high efficiency by using a plate reformer and which is small in size and lightweight.

[0009]

According to the present invention, in a hydrogen production apparatus for producing hydrogen by steam reforming a hydrocarbon, a plate reformer in which plate-like reforming chambers and combustion chambers are alternately laminated is provided. And a hydrogen purifier that adsorbs excess gas other than hydrogen at high pressure and desorbs it at low pressure to separate and purify hydrogen.
A surplus gas circulation line for introducing surplus gas separated by the hydrogen purifier into the plate reformer, and steam reforming hydrocarbons using the combustion heat of the surplus gas by the plate reformer to contain hydrogen Provided is a hydrogen production apparatus, which produces a reformed gas and separates and purifies hydrogen from the reformed gas by a hydrogen purification apparatus.

According to the above-mentioned constitution of the present invention, since a hydrogen purifying device (for example, H ₂ -PSA device) for adsorbing surplus gas other than hydrogen at high pressure and desorbing it at low pressure to separate and purify hydrogen is used, a high purity is obtained. Since hydrogen can be produced and the reforming gas containing hydrogen is produced by the plate reformer using the combustion heat of the excess gas separated by the hydrogen purification device, there is no release of impurities (excess gas) into the atmosphere. It is possible to prevent pollution and improve thermal efficiency. Furthermore, since a plate reformer that is essentially small and lightweight is used, the overall size and weight can be reduced.

According to a preferred embodiment of the present invention, a plate-type shift converter in which flat plate-shaped reaction chambers and air chambers are alternately stacked, and the reaction chambers are filled with a shift converter catalyst is further provided. A high-quality gas is flown, low-temperature air is flown in the air chamber, the temperature of the reaction chamber is cooled to a temperature suitable for the shift reaction by the amount of air, and the heated air is used for combustion in the plate reformer.

With this configuration, carbon monoxide in the reformed gas can be converted into hydrogen by a shift reaction, the hydrogen concentration can be increased, the amount of excess gas can be reduced, and the hydrogen production efficiency can be increased.

Further, the first plate heat exchanger for preheating the raw material gas by the reformed gas discharged from the plate reformer and the reformed gas discharged from the plate type shift converter are water-cooled to a temperature suitable for the hydrogen purifier. A second plate heat exchanger, a third plate heat exchanger that preheats the surplus gas separated by the hydrogen purification device with the combustion exhaust gas of the plate reformer, and a plate type exhaust heat recovery device that further evaporates water with the combustion exhaust gas And are preferably provided.

With this configuration, the temperature of each gas can be adjusted to the optimum temperature by using a compact heat exchanger, and the steam required for the reforming reaction can be produced from the exhaust gas, further improving the thermal efficiency. You can

Further, it is preferable that the plate reformer, the plate-type shift converter, and at least one plate heat exchanger are integrally laminated. With this configuration, it is possible to substantially integrate a plurality of devices having operating temperatures close to each other, and it is possible to reduce the heat retention of the piping between the devices and each part and further reduce the size of the entire device.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In the drawings, common parts are denoted by the same reference numerals. FIG. 1 is an overall configuration diagram of a hydrogen production device according to the present invention. In this figure, the hydrogen production apparatus 10 of the present invention is a plate reformer 1
2, hydrogen purifier 14, surplus gas circulation line 16
Is provided, and the source gas 2 is steam-reformed to produce the hydrogen gas 9.

The plate reformer 12 is a reformer in which flat plate-shaped reforming chambers Re and combustion chambers Co are alternately stacked, and the surplus gas generated in the hydrogen purifier 14 by the plate reforming device 12 is formed. The hydrocarbon 2 is steam-reformed using combustion heat of 13 (including CO, methane, etc.) to produce a reformed gas 4 containing hydrogen. The plate reformer 12 includes a reformer body 12a in which flat plate-shaped reforming chambers Re and combustion chambers Co are alternately stacked, and a reformer body 12a.
a primary combustor 12b which is installed outside a and supplies the combustion gas 8a to the combustion chamber Co. The combustion chamber Co is provided between the combustion gas inlet and the combustion exhaust gas outlet, and is a gas intermediate inflow means (for example, a perforated channel that crosses the combustion chamber and communicates with this channel) through which the fuel gas flows from the outside. And a secondary combustor 17 provided on the downstream side of the gas intermediate inflow means.

The plate reformer 12 described above burns a part of the required fuel gas 1 in the primary combustor 12b using excess air, thereby burning the combustion gas at a temperature at which the partition wall of the reformer is not overheated. To the secondary combustor 17 through the gas intermediate inflow means into the combustion gas whose temperature has been lowered by the reforming, and then the secondary combustion chamber 17 is preliminarily charged. The combustion gas can be burned by the excess air thus generated at a temperature at which the partition walls are not overheated. Therefore, the two-stage combustion can efficiently transfer the required heat amount of the combustion gas from the combustion chamber to the reforming chamber without causing deterioration of the combustion catalyst and reduction of the allowable stress of the partition wall.

The hydrogen purification device 14 is a device for adsorbing excess gas 13 other than hydrogen at high pressure and desorbing it at low pressure to separate and purify hydrogen. The surplus gas circulation line 16 introduces the surplus gas 13 separated by the hydrogen purifier 14 into the plate reformer 12.

Referring to FIG. 1, the hydrogen production apparatus 10 of the present invention.
Further includes a plate-type shift converter 18. The plate-type shift converter 18 is an apparatus in which flat plate-shaped reaction chambers 18a and air chambers 18b are alternately stacked, and the reaction chambers 18a are filled with a shift converter catalyst 18c. Sink, air chamber 1
The low temperature air 7 is made to flow to 8b by the compressor 19, the reaction chamber temperature is cooled to a temperature suitable for the shift reaction by the amount of the low temperature air 7, and the heated air is used for the combustion of the plate reformer 12. ing.

Further, the hydrogen producing apparatus 10 of the present invention is the first
Plate heat exchanger 22, second plate heat exchanger 24, third plate heat exchanger 26, and plate-type exhaust heat recovery device 2
8 is provided. The first plate heat exchanger 22 preheats the raw material gas 2 with the reformed gas 4 that has left the plate reformer 12. In addition, the second plate heat exchanger 24 uses the reformed gas 4 discharged from the plate-type shift converter 18 for the hydrogen purification device 1
Water cool to a temperature suitable for 4. Furthermore, the third plate heat exchanger 26 uses the surplus gas 1 separated by the hydrogen purifier 14.
3 is preheated with the combustion exhaust gas 8b of the plate reformer 12.
Further, the plate-type exhaust heat recovery device 28 is adapted to evaporate the water 11 by the combustion exhaust gas 8b.

In FIG. 1, the fuel gas 1 (for example, city gas) is mixed with the steam 11a generated in the plate-type exhaust heat recovery device 28 (waste heat boiler) at the confluence A to become the process gas 2 (raw material gas). , Enters the low temperature side 22a of the first plate heat exchanger 22 and, after being heated, the plate reformer 12
Flows into. The reforming reaction of the process gas 2 flowing into the plate reformer 12 is promoted by the combustion heat from the combustion chamber Co of the reformer 12, and is reformed into the reformed gas 4 containing hydrogen and carbon monoxide.

The reformed gas 4 enters the high temperature side 22b of the first plate heat exchanger 22, is cooled, and then enters the plate type shift converter 18. The combustion air 7 flows into the shift converter 18 on the low temperature side, and cools down to about 220 ° C. The shift converter 18 is provided with a layer filled with a low-temperature shift converter catalyst (Cu-Zn-based), and the reformed gas from the reformer is passed therethrough to convert carbon monoxide into hydrogen, thereby reducing the concentration of carbon monoxide. Is 0.5 vol% or less.

FIG. 2 shows a low temperature shift converter catalyst (C
u-Zn system) shift converter outlet temperature and CO
It is a relation diagram of density. As is clear from this figure, by controlling the outlet temperature (that is, reaction temperature) of the shift converter 18 to about 210 to 230 ° C., the concentration of carbon monoxide in the reformed gas is reduced to about 0.5 vol% or less. It is possible to increase the hydrogen concentration, reduce the amount of excess gas, and increase the hydrogen production efficiency.

The reformed gas 4 from the shift converter 18 flows into the high temperature side 24a of the second plate heat exchanger 24.
On the low temperature side 24b of the second plate heat exchanger 24, the cooling water 1
1 is flowing. The cooling water 11 whose temperature has risen undergoes heat exchange with the atmosphere in the cooling tower 15, and is then sent to the low temperature side 24b of the second plate heat exchanger 24 by the pump 15a. The reformed gas 4 that has left the second plate heat exchanger 24 has its water content removed at the branch point B, and then flows into the hydrogen purification device 14.

The hydrogen purifier 14 applies, for example, the principle of adsorption purification, and H ₂ -PAS (Pressure Swing Abs) which separates and purifies gas due to the difference in gas adsorption performance due to pressure fluctuation.
orber). The recovery efficiency of hydrogen 9 increases as the pressure increases, but the recovery efficiency is about 75% when the operating pressure is 10 ata or less. The exhaust gas of the PSA 14 contains hydrogen, carbon monoxide, and methane, which are used as heating fuel for the reformer 12. The exhaust gas (excess gas 13 other than hydrogen) from the PSA 14 flows into the low temperature side 26a of the third plate heat exchanger 26, receives heat from the exhaust gas 8a of the reformer 12 flowing through the high temperature side 26b, and is heated, It flows into the primary combustor 12b, is mixed with the combustion air 7 from the shift converter 18, and is combusted. Calorifically PSA1
Since the exhaust gas 13 from 4 is insufficient, additional fuel gas 1 (city gas) is required.
Mix with the exhaust gas 13 of 14. In addition, as indicated by an arrow E in the figure, the fuel gas 1 is fed to the exhaust gas 1 on the upstream side of the heat exchanger 26.
3 may be mixed.

The exhaust gas temperature of the primary combustor 12b is set to 800 ° C.
The primary combustor 1 is provided with the flow rate adjusting valve 12c as follows.
The fuel flow rate to 2b is controlled. The remaining fuel is combusted in the secondary combustor 17 incorporated in the reformer body 12a. At this time, the amount of oxidizing gas (in this case, the air flow rate 7) is determined so that the adiabatic flame temperature of the secondary combustion (the combustion gas temperature when the oxidizing gas of the fuel gas burns in an adiabatic state) becomes 800 ° C or less. There is.

The combustion gas 8 from the plate reformer 12 exiting the third plate heat exchanger 26 enters the exhaust heat recovery device 28, is used for steam generation, and is then discharged to the atmosphere. A packed bed of the reforming catalyst is provided on the reforming side of the plate reformer 12, and when the process gas (raw material gas 2) passes through this packed bed,
The reforming reaction proceeds by receiving heat from the combustion side. The secondary combustor 17 included in the plate reformer 12 has a layer filled with a combustion catalyst, and efficient combustion is secured by passing through this layer.

FIG. 3 shows the temperature of the reforming chamber before the secondary combustion by the secondary combustor 17 (horizontal axis), the adiabatic flame temperature during the secondary combustion by the secondary combustor 17, and the air flow rate (vertical axis). It is a relationship diagram. In addition, this figure shows a case where the city gas is steam-reformed and air is used as the oxidizing gas, and the temperature of the combustion gas 8a supplied from the primary combustor 12b (that is, the adiabatic flame in the primary combustor 12b). Temperature) to 800 ° C
And

From FIG. 3, the adiabatic flame temperature at the time of secondary combustion by the secondary combustor 17 is the temperature at which the partition wall is not overheated (for example, 80).
It is understood that the temperature of the reforming chamber before secondary combustion should be low (for example, 585 ° C. or lower) and the air flow rate should be high in order to keep the temperature below 0 ° C.). That is, when the reformed gas temperature at the secondary fuel injection location is lowered, the amount of heat required for the reforming reaction from the secondary fuel injection location to the reforming outlet increases, so the air flow rate in the primary combustor 12b increases. Further, as the air flow rate increases, the primary combustor 12b
If the adiabatic flame temperature of is maintained at 800 ° C, the primary combustor 1
Since the fuel flow rate of 2b increases and the fuel flow rate of the secondary combustor 17 decreases, the adiabatic flame temperature during secondary combustion decreases.

FIG. 4 shows the relationship between the fuel ratio of the primary combustor 12b (flow rate ratio to the whole) and the reformed gas temperature before the secondary combustion by the secondary combustor 17. From this figure, it can be seen that the fuel ratio of the primary combustor 12b increases as the reformed gas temperature before secondary combustion decreases. Further, when the adiabatic flame temperature of the secondary combustor is 800 ° C., the fuel flow rate ratio of the primary combustor is 70%, and the remaining 30% burns in the secondary combustor.

FIG. 5 is a perspective view in which the plate reformer 12, the shift converter 18, and the heat exchangers 22 and 26 are integrally piled. That is, this figure shows the plate reformer 1
2, the plate-type shift converter 18, and the hydrogen production device 10 in which the two plate heat exchangers 22 and 26 are integrally laminated are shown in separate states. The exhaust heat recovery device 28 and the other heat exchangers 24, 28 may be piled together, but they are omitted here. Since each device has a different operating temperature, a heat insulating material (not shown) is required between the devices. A primary combustor 12b is installed in the fuel air line between the shift converter 18 and the reformer 12. The preheated combustion air 7 from the shift converter 18, the preheated fuel (exhaust gas 13) from the PSA 14 and a part of the refueling fuel gas 1 are mixed and burned in the primary combustor 12b.

Since the air flow rate is determined so that the temperature of the combustion gas at the outlet of the primary combustor 12b does not exceed 800 ° C., the surplus oxygen is sufficient, and the secondary combustor 17 built in the reformer 12 remains. After mixing with the fuel gas, it is used again for combustion. The outlet gas temperature of the primary combustor 12b is 80
It is detected by a thermocouple so as not to exceed 0 ° C., and this signal is used to control by the fuel control valve 12c.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0035]

According to the configuration of the hydrogen production apparatus of the present invention described above, a hydrogen purification apparatus (for example, H _2-) that adsorbs excess gas other than hydrogen at high pressure and desorbs it at low pressure to separate and purify hydrogen.
Since a high-purity hydrogen can be produced by using the PSA device, and the reformed gas containing hydrogen is produced by the plate reformer using the combustion heat of the surplus gas separated by the hydrogen purification device, impurities ( Excessive gas) is not released into the atmosphere, air pollution can be prevented, and thermal efficiency can be improved. Furthermore,
Since it uses a plate reformer that is essentially small and lightweight,
The whole can be made small and lightweight.

Further, the plate-type shift converter can convert carbon monoxide in the reformed gas into hydrogen by a shift reaction, thereby increasing the hydrogen concentration and reducing the amount of surplus gas to improve the hydrogen production efficiency. it can. Furthermore, the temperature of each gas can be adjusted to an optimum temperature using a compact plate heat exchanger, and the steam required for the reforming reaction can be produced from the exhaust gas, so that the thermal efficiency can be further improved.

Further, by integrally laminating the plate reformer, the plate type shift converter, and the plate heat exchanger,
It is possible to substantially integrate a plurality of devices having operating temperatures close to each other, and to miniaturize the heat retention of the piping between the devices and each part to further reduce the size of the entire device.

Therefore, the hydrogen producing apparatus of the present invention has the excellent effects that high-purity hydrogen can be produced with high efficiency and that the whole is small and lightweight.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a hydrogen production device according to the present invention.

FIG. 2 is a relationship diagram between shift converter outlet temperature and CO concentration.

FIG. 3 is a relationship diagram of a reforming chamber temperature before secondary combustion, an adiabatic flame temperature during secondary combustion, and an air flow rate.

FIG. 4 is a relationship diagram between a fuel ratio of the primary combustor and a reformed gas temperature before secondary combustion by the secondary combustor.

FIG. 5 is a perspective view in which a plate reformer, a shift converter, and two heat exchangers are integrated into a pile.

FIG. 6 is a principle diagram of a conventional plate reformer.

[Explanation of symbols]

 1 Fuel Gas 2 Raw Material Gas (Process Gas) 3 Reforming Catalyst 4 Reforming Gas 5 Combustion Catalyst 6a-6e External Manifold 7 Combustion Air 8a Combustion Gas 8b Combustion Exhaust Gas 9 Hydrogen Gas 10 Hydrogen Production Device 11 Water Supply 11a Steam 12 Plate Modification Pourer 12a Reformer body 12b Primary combustor 12c Flow rate control valve 13 Excess gas (exhaust gas) 14 Hydrogen purification device (PSA) 15 Cooling tower 16 Excess gas circulation line 17 Secondary combustor 18 Plate type shift converter 22 First plate Heat exchanger 24 Second plate heat exchanger 26 Third plate heat exchanger 28 Plate type exhaust heat recovery device Re Reforming chamber Co Combustion chamber

Claims (4)

[Claims] 1. A hydrogen producing apparatus for producing hydrogen by steam reforming hydrocarbons, comprising a plate reformer in which flat plate reforming chambers and combustion chambers are alternately stacked, and a surplus gas other than hydrogen. It is equipped with a hydrogen purifier that adsorbs at high pressure and desorbs at low pressure to separate and purify hydrogen, and a surplus gas circulation line that introduces surplus gas separated by the hydrogen purifier into the plate reformer. A hydrogen production apparatus, wherein steam is used to reform hydrocarbons by using combustion heat of surplus gas to produce a reformed gas containing hydrogen, and hydrogen is separated and refined from the reformed gas by a hydrogen purification apparatus. 2. A plate-type shift converter in which flat plate-shaped reaction chambers and air chambers are alternately stacked, and the reaction chambers are filled with a shift converter catalyst, the reformed gas is flown into the reaction chambers, and the air chambers are supplied to the air chambers. Let cool air flow,
With the amount of air, the temperature of the reaction chamber is cooled to a temperature suitable for the shift reaction, and the heated air is used for combustion in the plate reformer.
The hydrogen production device according to claim 1, wherein the hydrogen production device is provided. 3. A first plate heat exchanger for preheating the raw material gas with the reformed gas discharged from the plate reformer, and the reformed gas discharged from the plate shift converter up to a temperature suitable for the hydrogen purifier. A water-cooled second plate heat exchanger, a third plate heat exchanger that preheats the surplus gas separated by the hydrogen purifier with the combustion exhaust gas of the plate reformer, and a plate-type exhaust heat that further evaporates water with the combustion exhaust gas The hydrogen production apparatus according to claim 2, further comprising a collector. 4. The hydrogen generator according to claim 3, wherein the plate reformer, the plate shift converter, and at least one plate heat exchanger are integrally laminated.