JPH107402A - Fuel cell reactor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A highly efficient fuel cell reaction including a desulfurizer having a desulfurization catalyst layer and a heat exchanger related to the desulfurizer, which makes the entire reactor system compact and has a small amount of heat radiation around the reactor. Is to provide equipment. SOLUTION: A raw material gas is put into a desulfurization catalyst layer 18 of a central cylinder of a reactor main body 17 and passed therethrough, then is put into a reformer 3, and a steam reformed gas reformed by the reformer 3 is supplied to the reactor main body 1.
7 is placed inside the LTS catalyst layer 9 divided by the LTS catalyst layer partition plate 21 and guided from the inner LTS catalyst layer 9a to the outer LTS catalyst layer 9b. Then, the hydrogen-rich reformed gas is led to the fuel cell main body. On the other hand, cooling water is supplied to the LTS catalyst layer cooling duct 22 formed on the LTS catalyst layer partition plate 21 to cool the LTS catalyst layer 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for desulfurizing a raw material gas and mixing steam to produce a steam reformed gas containing carbon monoxide and steam, thereby reducing carbon monoxide contained in the steam reformed gas. The present invention relates to a fuel cell reactor for obtaining a hydrogen-rich reformed gas.

[0002]

2. Description of the Related Art Generally, a fuel cell power generation system converts chemical energy of a raw material gas such as natural gas or propane gas into electric energy. In this case, the raw material gas is reformed to obtain a hydrogen-rich reformed gas,
The hydrogen-rich gas is supplied to the fuel cell body to generate power.

[0003] Sulfur compounds contained in the raw material gas are removed by a desulfurizer, and the desulfurized fuel gas is added with steam by an ejector and reformed by a reformer to become a steam reformed gas. Since this steam reformed gas contains carbon monoxide, carbon monoxide is removed by a carbon monoxide converter. Then, a hydrogen-rich reformed gas from which carbon monoxide has been removed is supplied to the fuel cell main body, and hydrogen and oxygen are reacted to generate electricity. Since the power generated by the fuel cell body is DC power, the DC is converted to AC by a converter and transmitted to a power system. Here, in the fuel cell power generation system, an important device such as a heat exchanger for maintaining the temperature of the differential gas at a temperature suitable for operation of the fuel cell body and hydrogen generation is also provided.

FIG. 12 is an explanatory diagram of a process for obtaining a hydrogen-rich reformed gas from a raw material gas. The raw material gas containing hydrocarbon as a main component is supplied with steam to the hydrogenator 1 to be converted into hydrogen sulfide, which is easy to adsorb and remove organic sulfur, and then supplied to the desulfurizer 1.

[0005] The desulfurizer 2 is for removing sulfur compounds in the raw material gas, and partially recirculates the hydrogen-rich reformed gas supplied to the fuel cell body through a recycling line. The inside of the desulfurizer 2 is filled with a desulfurization catalyst, and by the action of the desulfurization catalyst, sulfur compounds in the raw material gas are removed by the following reaction.

[0006]

(Equation 1)

As is apparent from the above formulas (1) and (2), conversion of a sulfur compound to hydrogen sulfide requires the addition of hydrogen. For this reason, a part of the reformed gas rich in hydrogen after reforming is supplied to the inlet of the desulfurizer 2 through the recycle line.

[0008] The desulfurized raw material gas is supplied to the reformer 3. In the reformer 3, steam is added to the raw material gas, and the raw material gas is converted into hydrogen required for the fuel cell body by the action of a catalyst filled therein. The reaction formula is shown below.

[0009]

(Equation 2)

As can be seen from the above equation (3), the reformer 3
Outlet gas contains a large amount of carbon monoxide CO. Since this carbon monoxide has a bad effect on the catalyst of the fuel cell body, it must be reduced as much as possible. In other words, the noble metal catalyst such as a platinum catalyst is used for the electrode of the fuel cell body, and the activity is reduced by poisoning by the carbon monoxide contained in the reformed gas. It is necessary that the amount of carbon monoxide in the gas be 1.0% or less. Therefore, in order to reduce the carbon monoxide, a high-temperature carbon monoxide converter 5 and a low-temperature carbon monoxide converter 7 are installed downstream of the reformer 3.

That is, 700 ° C. to 800 ° C. in the reformer 3
The steam reformed gas, which has been steam reformed at 0 ° C., exchanges heat with a cooling medium by a first-stage heat exchanger to lower its temperature. The reformed gas is further heat-exchanged with a cooling medium in a second-stage heat exchanger 6 to lower its temperature, and then reformed at a low-temperature carbon monoxide converter 7. At 200 ° C. to 300 ° C. under a low temperature LTS catalyst to remove carbon monoxide.

Inside the high-temperature carbon monoxide converter 5, HT
The S catalyst is filled, and the LTS catalyst is filled inside the low-temperature carbon monoxide converter 7. In these catalyst layers, a shift reaction represented by the following formula (4) is performed, At the outlet of the reactor, carbon monoxide is reduced while increasing the amount of hydrogen required for power generation.

[0013]

(Equation 3)

Since this reaction is a reversible reaction, a reaction to the left proceeds simultaneously with a reaction to the right. The degree of the reaction is determined by the reaction rate of the mixed gas and the chemical equilibrium value. That is, when the temperature is high, the reaction rate is high, but the equilibrium constant is small, so that equilibrium is reached in a state where the concentration of carbon monoxide is high. Therefore, the shift reaction is performed in two stages of the high-temperature carbon monoxide converter 5 and the low-temperature carbon monoxide converter 7.

Here, if a two-stage carbon monoxide converter is used, the size of the apparatus becomes large. Therefore, as shown in JP-A-2-188406, a two-stage carbon monoxide converter and a heat exchanger are used. An integrated one has been proposed.

FIG. 13 is an explanatory diagram of such a one-stage carbon monoxide converter. This is the high temperature HTS catalyst layer 8
The LTS catalyst layer 9 for low temperature is housed in the same casing 10 for compactness.

That is, an inlet 11 for introducing a steam reformed gas is provided at an upper portion of the casing 10, an outlet 12 for outputting a reformed gas from which carbon monoxide has been removed is provided at a lower portion of the casing 10, and an inlet mesh 13 is provided. The HTS catalyst layer 8 is formed inside the partition mesh 14 and the LT is formed inside the partition mesh 14 and the outlet mesh 15.
An S catalyst layer 9 is formed. Then, a serpentine pipe 16 of cooling water is provided in the HTS catalyst layer 8 to cool the HTS catalyst layer 8. That is, the high-temperature carbon monoxide converter 5, the second-stage heat exchanger 6, and the low-temperature carbon monoxide converter 7 shown in FIG. 12 are housed in one casing 10 to make the equipment compact.

[0018]

However, such a reactor has the following problems. (1) Since the cooling coil 16 is formed in a coil shape,
It is difficult for catalyst particles to enter the space between the tubes, and the HTS catalyst is not uniformly filled. Therefore, the flow of the steam reforming gas becomes uneven, and the temperature distribution and the carbon monoxide concentration of the gas at the outlet of the high-temperature carbon monoxide converter become uneven. (2) In general, the catalyst reaches its life after a certain period of operation. At that time, the catalyst must be replaced.
In particular, when the HTS catalyst is replaced, the coil-shaped cooling tube becomes a hindrance, and the working time is long.

An object of the present invention is to make a whole reactor system compact including a desulfurizer having a desulfurization catalyst layer and a heat exchanger related to the desulfurizer, and to provide a highly efficient fuel cell reaction system with a small amount of heat radiation around the reactor. Is to provide equipment.

[0020]

According to the first aspect of the present invention, a raw material gas is desulfurized through a desulfurization catalyst, mixed with steam in an ejector, reformed in a reformer, and reformed in a steam reformer containing carbon monoxide and steam. Of a fuel cell that generates a reformed gas, reduces carbon monoxide contained in a steam reformed gas, and obtains a hydrogen-rich reformed gas, and is a reactor formed of a double cylindrical container A main body, a desulfurization catalyst layer that is housed in a central cylinder of the reactor body covered with a heat insulator and contributes to a reaction for removing a sulfur compound from a raw material gas, and an outer cylindrical portion of the reactor body covered with a heat insulator. An LTS catalyst layer contributing to a low-temperature reaction for removing carbon monoxide from the stored steam reformed gas, and a cylindrical LTS catalyst layer partition plate provided so as to concentrically divide the LTS catalyst layer. LT formed on the LTS catalyst layer partition plate Is obtained by a LTS catalyst layer cooling duct through which cooling water for cooling the catalyst layer.

According to the first aspect of the present invention, the raw material gas is put into the desulfurization catalyst layer of the central cylinder of the reactor body, passes therethrough, and then enters the reformer. It is placed inside the LTS catalyst layer divided by the LTS catalyst layer partition plate of the main body, and is guided from the inner LTS catalyst layer to the outer LTS catalyst layer. Then, the hydrogen-rich reformed gas is led to the fuel cell main body. On the other hand, cooling water is supplied to the LTS catalyst layer cooling duct formed on the LTS catalyst layer partition plate to cool the LTS catalyst layer.

According to a second aspect of the present invention, in the first aspect of the present invention, the LTS catalyst layer cooling duct is provided with a concave groove in a circumferential direction of the two LTS catalyst layer partition plates, and the two LTS catalyst layer partition plates are provided. It is formed as a single cooling channel that is formed by sealingly joining the concave grooves of the plate to face each other and communicating with each other.

According to a second aspect of the present invention, in addition to the operation of the first aspect, the cooling water is supplied to the LTS catalyst layer cooling duct, which is one cooling channel formed by joining two LTS catalyst layer partition plates. Water is passed to cool the LTS catalyst layer.

According to a third aspect of the present invention, in the second aspect of the present invention, the cooling duct for the LTS catalyst layer has a reduced flow path cross-sectional area up to the middle of the cooling flow path, and the LTS catalyst layer has a flow area near the point where the cooling medium is evaporated. The road cross-sectional area is enlarged.

According to the third aspect of the invention, in addition to the operation of the second aspect, the cooling water in the liquid phase flows through the cooling channel having a small cross-sectional area, and the cooling water in the gaseous state flows through the cross-sectional area of the flow channel. And efficiently removes heat to promote the reaction in the LTS catalyst layer.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a high temperature for removing carbon monoxide from the steam reforming gas is provided at the center of the desulfurization catalyst layer housed in the center cylinder of the reactor body. To form an HTS catalyst layer contributing to the reaction in step 1, separating the desulfurization catalyst layer and the HTS catalyst layer with a cylindrical catalyst layer partition plate, guiding the raw material gas to the desulfurization catalyst layer and heating the raw material gas in the process. The raw material gas heating duct is formed in the catalyst layer partition plate, and the HTS catalyst layer is concentrically formed into a cylindrical HTS.
The HTS catalyst layer partition plate is separated by HT.
An HTS catalyst layer cooling duct for passing cooling water for cooling the S catalyst layer is formed, and the reformed gas that has passed through the HTS catalyst layer is led to the LTS catalyst layer while heating the desulfurization catalyst layer in the process. The desulfurization catalyst layer heating duct is provided on the cylindrical side wall of the desulfurization catalyst layer.

According to a fourth aspect of the present invention, in addition to the operation of the first aspect, the raw material gas is guided to the desulfurization catalyst layer of the reactor body while being heated through the raw material gas heating duct, and is desulfurized by the desulfurization catalyst layer. The raw material gas is supplied to an ejector. Then, the steam reformed gas flowing out of the reformer which heats the desulfurized raw material gas and steam to cause a catalytic reaction is introduced into the HTS catalyst layer at the center of the reactor body, and the reformed gas passing through the HTS catalyst layer is introduced. Is heated through the desulfurization catalyst layer heating duct to heat the desulfurization catalyst layer, is led to the LTS catalyst layer, and is supplied as a hydrogen-rich reformed gas to the fuel cell body. On the other hand, HTS
The catalyst layer is cooled by passing cooling water through an HTS catalyst layer cooling duct, and the LTS catalyst layer is cooled by passing cooling water through an LTS catalyst layer cooling duct.

According to a fifth aspect of the present invention, in the invention of the fourth aspect, the raw material gas heating duct, the HTS catalyst layer cooling duct, or the desulfurization catalyst layer heating duct is provided with a concave groove in the circumferential direction of the two partition plates. The two partitioning plates are formed so as to face each other with the concave grooves facing each other and hermetically joined to form a single communicating channel.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the raw material gas heating duct, the HTS catalyst layer cooling duct,
Alternatively, the desulfurization catalyst layer heating duct performs heat exchange by passing a fluid through a duct that is one flow path formed by joining two partition plates.

According to a sixth aspect of the present invention, in the first aspect of the present invention, a plurality of small-diameter heat transfer tubes having a small diameter are provided inside the desulfurization catalyst layer accommodated in the central cylinder of the reactor body. An HTS catalyst layer is filled on the inside, and a water cooling pipe for passing cooling water for cooling the HTS catalyst layer is provided.

According to the sixth aspect of the invention, in addition to the operation of the first aspect, the raw material gas is guided to the desulfurization catalyst layer of the reactor body, and the raw material gas desulfurized by the desulfurization catalyst layer is supplied to the ejector. Then, the steam reformed gas flowing out of the reformer, which performs a catalytic reaction by heating the desulfurized raw material gas and steam, is put into the HTS catalyst layer of the heat transfer tube inside the reactor body, and the HT
The reformed gas that has passed through the S catalyst layer is led to the LTS catalyst layer,
It is supplied as a hydrogen-rich reformed gas to the fuel cell body. On the other hand, the HTS catalyst layer is cooled by passing cooling water through a water cooling pipe provided inside the heat transfer pipe. That is, heat is exchanged between the HTS catalyst layer inside the heat transfer tube and the desulfurization catalyst outside, so that carbon monoxide is reduced inside and the sulfur contained in the raw material gas is removed outside.

According to a seventh aspect of the present invention, a raw material gas is desulfurized through a desulfurization catalyst, steam is mixed by an ejector, and reformed by a reformer to produce a steam reformed gas containing carbon monoxide and steam. This is a fuel cell reactor that reduces the carbon monoxide contained in the steam reformed gas to obtain a hydrogen-rich reformed gas, and is formed in a cylindrical vessel having a large diameter to remove sulfur compounds from the raw material gas. A reactor main body containing a desulfurization catalyst layer contributing to the reaction, a small-diameter double-walled heat transfer tube disposed inside the reactor main body, and one of the steam reforming gas stored above the heat transfer tube. An HTS catalyst layer that contributes to a high-temperature reaction for removing carbon oxide, and an LTS catalyst layer that is housed in the lower part of the heat transfer tube and contributes to a low-temperature reaction for removing carbon monoxide from steam reformed gas. Installed inside the heat transfer tube A water cooling pipe through which cooling water for cooling the HTS catalyst layer and the LTS catalyst layer is passed, and a helical spacer attached between the pipe walls of the heat transfer pipe having a double pipe structure are formed to guide the raw material gas to the desulfurization catalyst layer. And a source gas heating duct for heating the source gas in the process, and a desulfurization catalyst layer heating duct for guiding the steam reforming gas to the heat transfer tube and heating the desulfurization catalyst layer in the process. .

According to the seventh aspect of the present invention, the raw material gas is guided to the desulfurization catalyst layer of the reactor body while being heated through the raw gas heating duct, and the raw material gas desulfurized by the desulfurization catalyst layer is supplied to the ejector. Then, the steam reformed gas flowing out of the reformer, which heats the desulfurized raw material gas and steam to cause a catalytic reaction, is heated through a desulfurization catalyst layer heating duct and provided with heat transfer provided inside the reactor main body. H at the top inside the tube
The reformed gas that has entered the TS catalyst layer and passed through the HTS catalyst layer is guided to the lower LTS catalyst layer in the heat transfer tube, and is supplied as a hydrogen-rich reformed gas to the fuel cell body. On the other hand, H
The TS catalyst layer and the LTS catalyst layer are cooled by passing cooling water through a water cooling pipe provided inside the heat transfer tube.

[0034]

Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram showing a first embodiment of the present invention. In the first embodiment, a reactor main body 17 is formed of a double cylindrical container, and a desulfurization catalyst container 19 for storing a desulfurization catalyst (HDS) 18 is provided in a central cylinder of the reactor main body 17. And a double cylindrical LHS catalyst layer container 20 provided on the same axis. The LHS catalyst layer container 20 contains L
The LHS catalyst layer 9 is housed therein. The LHS catalyst layer 9 is divided into two sections by an LTS catalyst layer partition plate 21.
2 are formed. The desulfurization catalyst container 19 and the LTS catalyst layer container 20 are covered with a heat insulating material.

A source gas such as city gas is supplied from a fuel supply line 23 to a desulfurization catalyst layer 18 of a reactor body 17. The fuel supply line 23 is connected to a recycle line 26 for taking in the hydrogen-rich reformed gas to be supplied to the fuel cell main body 24 into the fuel supply line 23 via the orifice 25.

The raw material gas put in the desulfurization catalyst layer 8 passes therethrough, is desulfurized, and is put into the ejector 27. The raw material gas after desulfurization put in the ejector 27 is mixed with the steam heated in the first heat exchanger 28 and supplied to the reformer 3. In the reformer 3, the raw material gas is reformed into hydrogen, and enters the LTS catalyst layer 9 of the reactor body 17 through the first heat exchanger 28 and the second heat exchanger 29 as a steam reformed gas.

In this case, the first catalyst layer 9a on the inner side separated by the LTS catalyst layer partition plate 21 enters, turns at the lower part, passes through the second catalyst layer 9b provided on the outside, and removes carbon monoxide. . Then, the gas becomes a hydrogen-rich reformed gas and is introduced into the fuel cell main body 24. A part of the hydrogen-rich reformer gas supplied to the fuel cell main body 24 is supplied to the desulfurization catalyst layer 18 through the recycle line 25 as described above.

In the above description, the steam reforming gas enters the inner first catalyst layer 9a, turns at the lower portion, and passes through the outer second catalyst layer 9b. Conversely, the hydrogen-rich reformed gas may be supplied to the fuel cell main body 24 through the second catalyst layer 9b on the outer side, turn at the lower part, pass through the first catalyst layer 9a provided on the inner side, and pass through.

The water (steam) generated by the chemical reaction in the fuel cell main body 24 is guided to the steam separator 30. The steam separator 30 separates moisture into steam and water.
The steam from the steam separator 30 is supplied to the ejector 27 as reforming steam via the first heat exchanger 28.
On the other hand, the water of the steam separator 30 is supplied to the second heat exchanger and the LTS catalyst layer cooling duct 22 of the reactor main body 17 by the cooling water supply pump 31. Second heat exchanger 29
Is to heat-exchange the temperature of the steam reformed gas to a temperature suitable for the reaction for removing carbon monoxide. The LTS catalyst layer cooling duct 22 generates heat generated by the reaction for removing carbon monoxide. It removes heat.

FIG. 2 is a sectional view of the LTS catalyst layer partition plate 21. The LTS catalyst layer partition plate 21 is composed of two cylindrical partition plates 21a and 21b.
A concave groove is formed in each of a and 21b in the circumferential direction. The two partition plates 21a and 21b are tightly joined to each other with the concave grooves facing each other, and the space formed by this is used as an LTS catalyst layer duct 22 through which a cooling medium flows.

FIG. 3 shows the cylindrical partition plates 21a and 21b cut vertically and developed in the circumferential direction. As shown in FIG. 3, the LTS catalyst layer cooling duct 22 is connected to the cooling medium inlet hole 32 at the lower end, is connected to the duct configuration portion at one upper stage around about one circle, and so on. Is reciprocated and rises one step at a time, and is finally connected to the outlet 33 of the cooling medium. Then, the partition plates 21a and 21b are joined, bent in the circumferential direction, and left and right side ends are vertically welded to each other to form the LTS catalyst layer cooling duct 22.

In the first embodiment, the case where the HTS catalyst layer is not used is shown. This is because the two first heat exchangers 28 and the second heat exchanger 29
Since the temperature is lowered to a temperature at which the catalyst layer 9 can be used (approximately 270 ° C. or less), the LTS catalyst layer 9 is slightly increased in capacity without providing the HTS catalyst layer, and the LTS catalyst layer is used. This is because carbon monoxide can be reduced at the outlet of the catalyst layer 9.

In the LTS catalyst layer 9 according to the first embodiment, the inside of the first catalyst layer 9a is insulated, and the outside of the second catalyst layer 9b is radiated through the heat insulating material. Now
When the LTS catalyst layer cooling duct 22 is provided in the lower half of the LTS catalyst layer partition plate 21 and cooled with water, the temperature distribution and the concentration of carbon monoxide change as shown in FIG. 4 along the flow of the steam reforming gas. ing. That is, in the first catalyst layer 9a, the steam reforming gas rises to a maximum of 252 ° C. due to the exothermic reaction, whereby the reaction speed advances to a relatively high speed and the carbon monoxide amount decreases.

If the temperature is lowered by cooling from near the middle of the first catalyst layer 9a, the chemical equilibrium constant becomes large.
The reaction proceeds little by little, and the carbon monoxide concentration further decreases.

In the case of the temperature distribution characteristic shown in FIG.
The carbon monoxide concentration at the outlet of the S catalyst layer 9 can be minimized. The carbon monoxide concentration at the outlet increases if the temperature is too low or too low.

Thus, the lower half of the first catalyst layer 9a and the second half
It is most effective to cool the lower half of the catalyst layer 9b with the cooling water of the battery body. When a catalyst whose maximum use temperature is about 290 ° C. to 300 ° C. is used as the LTS catalyst, the life is not affected since the first embodiment is used at a sufficiently low temperature of 252 ° C. .

Next, a second embodiment of the present invention will be described. FIG. 5 is a developed view in which the LTS catalyst layer partition plate according to the second embodiment of the present invention is cut vertically and developed in the circumferential direction. The second embodiment is different from the LTS catalyst layer cooling duct 22 of the first embodiment shown in FIG. LT with a larger cross-sectional area before the point
This adopts an S catalyst layer cooling duct 22.

Referring to FIG. 5, this second embodiment is
The cross-sectional area of the LTS catalyst layer cooling duct 22 is changed in the direction of flow. The LTS catalyst layer cooling duct 22 has a branch point 34 in the middle of the flow of cooling water as a cooling medium.
The cross-sectional area is composed of one concave groove.
Above 4, the cooling ducts are configured to flow simultaneously into two concave grooves of the cooling duct constituting portion in the circumferential direction. The branch point 34 is not limited to two concave grooves, but may be configured to flow simultaneously to a plurality of grooves.

In the second embodiment, since the volume of water and steam becomes about 10 times downstream of the LTS catalyst layer cooling water duct 22 due to evaporation of the cooling water by heating, the sectional area is increased. Accordingly, the flow of the cooling water can be rationalized.

Next, a third embodiment of the present invention will be described. FIG. 6 is a configuration diagram showing a third embodiment of the present invention. This third embodiment is different from the first embodiment shown in FIG. 1 in that the central portion 18 of the desulfurization catalyst layer housed in the central cylinder of the reactor main body is provided with carbon monoxide from steam reforming gas. The HTS catalyst layer 8 which contributes to the reaction at a high temperature for removing the HTS is formed. An HTS catalyst layer partition plate 36 having an HTS catalyst layer cooling duct 35 is provided in the HTS catalyst layer 8, and the desulfurization catalyst layer 18 and the HTS catalyst are separated by a catalyst layer partition plate 38 having a source gas heating duct 37. Layer 8
And are divided. Further, a desulfurization catalyst layer heating duct 39 for heating the desulfurization catalyst layer 18 with the reformed gas that has passed through the HTS catalyst layer 8 is provided. Other configurations are the same as those of the first embodiment shown in FIG. 1, and therefore, the same portions are denoted by the same reference characters and description thereof will be omitted.

In FIG. 6, the central portion of the inner vessel of the reactor main body 17 formed in a coaxial multi-cylindrical shape is filled with an HTS catalyst layer 8, and the periphery of the HTS catalyst layer 8 is separated by a catalyst layer partition plate 38. Fill 18

The HTS catalyst layer 8 is divided into an inner catalyst layer 8a and an outer catalyst layer 8b. An HTS catalyst layer partition plate 36 is inserted between the inner catalyst layer 8a and the outer catalyst layer 8b. An HTS catalyst layer cooling duct 35 is formed in the HTS catalyst layer partition plate 36. I have. The HTS catalyst layer cooling duct 35 is configured similarly to the LTS catalyst layer cooling duct 22 of the first embodiment in FIG. The cooling water flows through the HTS catalyst layer cooling duct 34 to cool the HTS catalyst layer 8.

On the other hand, a raw material gas heating duct 37 is formed on the catalyst layer partition plate 38 outside the outer catalyst layer 8b.
A gas (source gas) in which the source gas and the recycle gas are mixed is introduced and heated by the source gas heating duct 29.

Further, a desulfurization catalyst layer heating duct 39 is provided outside the desulfurization catalyst layer 18, and gas discharged from the HTS catalyst layer 8 is introduced into the desulfurization catalyst layer heating duct 39 via the connection pipe 40. The desulfurization catalyst layer 31 is heated while passing through the desulfurization catalyst layer heating duct 39.

First, the raw material gas is mixed with the recycled gas from the recycling line 26,
7 and is heated in the course of passing through the source gas heating duct 37. The source gas that has passed through the source gas heating duct 37 is introduced into the desulfurization catalyst layer 18 through the connecting pipe 41, where it is desulfurized and supplied to the ejector 27. Then, it is mixed with the main steam in the ejector 27 and introduced into the reformer 3 to be a steam reformed gas.

The steam reformed gas from the reformer 3 is introduced into the HTS catalyst layer 8 of the reactor body, and carbon monoxide is removed by a high-temperature shift reaction. The gas leaving the HTS catalyst layer 8 passes through the connection pipe 40 and the desulfurization catalyst layer heating duct 39
And the temperature is lowered while exchanging heat with the desulfurization layer 18, and is introduced into the LTS catalyst layer 9 through the communication pipe 42. LT
In the S catalyst layer 9, carbon monoxide is removed by a low-temperature shift reaction and supplied to the fuel cell main body 24 as a reformed gas.

As described above, in the third embodiment,
Although the HTS catalyst layer 8 is used, it is provided to improve electric heat between the HTS catalyst layer and the raw material gas heating duct and the desulfurization catalyst heating duct 39 of the catalyst layer partition plate 38. Use of a heat transfer promoting material such as alumina balls in place of the HTS catalyst layer 8 is also effective. In the third embodiment, the HTS catalyst layer is used because the temperature is such that the soil HTS catalyst layer can be used. The raw material gas heating duct 37 and the desulfurization catalyst heating duct 39 have the same configuration as the LTS catalyst layer cooling duct 22 and the HTS catalyst layer cooling duct 35.

Next, a fourth embodiment of the present invention will be described. FIG. 7 is a configuration diagram showing a fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment shown in FIG. 1 in that a small-diameter heat transfer tube having a small diameter is provided inside a desulfurization catalyst layer 18 housed in a central cylinder of a reactor body 17. The HTS catalyst layer 8 is filled inside the heat transfer tube 43, and a water cooling tube 44 for passing cooling water for cooling the HTS catalyst layer 8 is provided. Other configurations are the same as those of the first embodiment shown in FIG. 1, and therefore, the same portions are denoted by the same reference characters and description thereof will be omitted.

In FIG. 7, a desulfurization catalyst layer 18 is filled in an inner container of a reactor main body 17 formed in a coaxial multi-cylindrical shape. Then, a plurality of small-diameter heat transfer tubes 43 having a small diameter are provided inside the desulfurization catalyst layer 18.

FIG. 8 is a sectional view taken along line AA of FIG.
In the fourth embodiment, a plurality of heat transfer tubes 43 are provided inside the desulfurization catalyst layer 18, and H
The TS catalyst layer 8 is filled. Further, a water cooling pipe 44 for passing cooling water for cooling the HTS catalyst layer 8 is provided. That is, a plurality of small-diameter heat transfer tubes 43 are erected inside a large-diameter inner cylindrical container, and a concentric water cooling tube 44 is provided inside the heat transfer tubes 43, and an HTS catalyst layer 8 is provided between the two tubes. Is provided.

As shown in FIG. 7, the cooling water supply pump 31
Is supplied to the inlet header 45, passes through the water cooling pipe 44 in each heat transfer pipe 43, exits to the outlet header 46, and returns to the steam separator 30. Entrance header 4
5 and the outlet header 46 are connected to all the water cooling pipes 44.

First, the raw material gas is mixed with the recycle gas from the recycle line 26 and introduced into the desulfurization catalyst layer 18 of the reactor body 17 where it is desulfurized and ejected.
Supplied to Then, it is mixed with the main steam in the ejector 27 and introduced into the reformer 3 to be a steam reformed gas. The steam reformed gas discharged from the reformer 3 is supplied to the HTS
It is introduced into the catalyst layer 8, exits from the lower part, and is introduced into the LTS catalyst layer 9 in the outer container of the reactor body by the connecting pipe 47. That is, the second catalyst layer 9b enters the first catalyst layer 9a on the inner side.
And is supplied to the fuel cell main body 24.

In the fourth embodiment, the HTS catalyst layer 8 is used as in the third embodiment, but this improves the electric heat between the HTS catalyst and the tube wall of the heat transfer tube 43. It is also effective to use a heat transfer promoting material such as alumina balls in place of the HTS catalyst.

Next, a fifth embodiment of the present invention will be described. FIG. 9 is a configuration diagram showing a fifth embodiment of the present invention. This fifth embodiment is different from the fourth embodiment shown in FIG. 7 in that the heat transfer tube 43 is a double tube, the HTS catalyst layer 8 is provided in the upper portion of the heat transfer tube 43, and the LTS catalyst is provided in the lower portion. The layer 9 is provided. Then, a raw material gas heating duct 37 is formed between the double tubes, and the raw material gas flows to exchange heat, and the steam reforming gas is supplied to the desulfurization catalyst layer heating duct 39.
To heat the desulfurization catalyst layer 18.

The double-walled heat transfer tube 43 according to the fifth embodiment is configured as shown in FIG. That is, the spacer 48 is provided outside the heat transfer tube 43, and the spacer 48 is spirally wound around the heat transfer tube 43 and partially welded. After attaching the spacer 43, the outer tube 49 is wound to provide a double spiral flow path. This spiral flow path becomes the raw material gas heating duct 37.

Further, the side wall of the container of the desulfurization catalyst layer 18 is made a double wall, and a spacer 51 is provided outside the inner container side wall 50. FIG. 11 is a developed view in which a spacer 51 attached to the inner container side wall 50 is developed in the circumferential direction. The spacer 51 is partially adhered to the inner container side wall 50 in the inclined direction, and is wound in the circumferential direction and welded. A double cylindrical outer wall 52 is placed on the outside.

The raw material gas is mixed with the reformed gas from the recycle line 26 and introduced into the lower part of the reactor main body 17.
Through the source gas heating duct 37 formed by the spiral flow path of the spacer 43 of the heat transfer tube 43 having the double tube structure, the heat is transferred by heat exchange with the HTS catalyst layer and the LTS catalyst layer 9 in the process. The raw material gas that has passed through the raw material gas heating duct 37 is introduced into the desulfurization catalyst layer 18 at the upper part of the reactor main body 17 to remove the sulfur content.

The desulfurized raw material gas is introduced into the ejector 27, mixed with steam, and sent to the reformer 3. The steam reforming gas discharged from the reformer 3 is supplied to the desulfurization catalyst layer 18.
, Enters the desulfurization catalyst layer heating duct 39 from the jacket inlet 53 around it, and heats the desulfurization catalyst layer 18 to form the upper connecting pipe 54.
Is introduced into the HTS catalyst layer 8. While flowing down the HTS catalyst layer 8, the steam reformed gas is cooled by the cooling water pipe 44 and enters the LTS catalyst layer 9 from the middle, where the hydrogen-rich reformed gas from which carbon monoxide has been removed exits from the lower end. The fuel is supplied to the fuel cell main body 24.

According to the fifth embodiment, since the HTS catalyst layer and the LTS catalyst layer are housed in the same heat transfer tube, the whole is compact, and the reactor is efficient and has a small amount of heat radiation. Can be obtained.

[0070]

As described above, according to the present invention, since the catalyst layer is in direct contact with the vessel wall, efficient heat transfer characteristics with good thermal conductivity can be obtained. Therefore, the heat transfer area can be made smaller than the conventional one, and the reformed gas having a uniform temperature distribution of carbon monoxide concentration can be obtained without causing uneven flow due to uneven filling of the catalyst layer. .

Further, since the conventional carbon monoxide converter, desulfurizer and related heat exchanger are combined into one, the whole can be made compact.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a sectional view of an LTS catalyst layer partition plate according to the first embodiment of the present invention.

FIG. 3 is a development view in which the LTS catalyst layer partition plate according to the first embodiment of the present invention is cut vertically and developed in the circumferential direction.

FIG. 4 is a characteristic diagram according to the first embodiment of the present invention.

FIG. 5 is a development view in which an LTS catalyst layer partition plate according to a second embodiment of the present invention is cut vertically and developed in a circumferential direction.

FIG. 6 is a configuration diagram showing a third embodiment of the present invention.

FIG. 7 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 8 is a sectional view taken along line AA of FIG. 7;

FIG. 9 is a configuration diagram showing a fifth embodiment of the present invention.

FIG. 10 is an explanatory diagram of a heat transfer tube having a double tube configuration according to a fifth embodiment of the present invention.

FIG. 11 is a development view in which a spacer attached to an inner container side wall according to a fifth embodiment of the present invention is developed in a circumferential direction.

FIG. 12 is an explanatory diagram of a step of obtaining a hydrogen-rich reformed gas from a source gas.

FIG. 13 is an explanatory view of a conventional one-stage carbon monoxide converter.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 hydrogenator 2 desulfurizer 3 reformer 4 first stage heat exchanger 5 high temperature carbon monoxide converter 6 second stage heat exchanger 7 low temperature carbon monoxide converter 8 HTS catalyst layer 9 LTS catalyst layer 10 Casing 11 Inlet 12 Outlet 13 Inlet mesh 14 Partition mesh 15 Outlet mesh 16 Serpentine tube 17 Reactor body 18 Desulfurization catalyst layer 19 Desulfurization catalyst layer container 20 LTS catalyst layer container 21 LHS catalyst layer partition plate 22 LHS catalyst layer cooling duct 23 Fuel supply line Reference Signs List 24 fuel cell main body 25 orifice 26 recycling line 27 ejector 28 first heat exchanger 29 second heat exchanger 30 steam-water separator 31 cooling water supply pump 32 inlet 33 outlet 34 branch point 35 HTS catalyst layer cooling duct 36 HTS Catalyst layer partition plate 37 Source gas heating duct 38 Catalyst layer partition plate 39 Desulfurization catalyst layer Duct 40 connecting pipe 41 connecting pipe 42 connecting pipe 43 heat transfer tube 44 water cooled pipe 45 inlet header 46 outlet header 47 connecting pipe 48 spacers 49 outer tube 50 inside the container sidewall 51 spacer 52 double cylinder outer wall 53 jacket inlet

Claims (7)

[Claims] 1. A raw material gas is desulfurized through a desulfurization catalyst, mixed with steam by an ejector and reformed by a reformer to produce a steam reformed gas containing carbon monoxide and steam, A reactor body formed of a double-cylindrical container; and a central cylinder of the reactor body, wherein the reactor is configured to obtain a hydrogen-rich reformed gas by reducing the carbon monoxide contained in the reactor body. A desulfurization catalyst layer that is housed and covered with a heat insulator and contributes to a reaction for removing a sulfur compound from the raw material gas, and is housed and covered with a heat insulator on the outer cylindrical portion of the reactor body from the steam reformed gas. An LTS catalyst layer that contributes to a low-temperature reaction for removing carbon monoxide;
A cylindrical LTS catalyst layer partition plate provided so as to concentrically divide the LTS catalyst layer, and an LTS catalyst layer formed on the LTS catalyst layer partition plate and passing cooling water for cooling the LTS catalyst layer A reactor for a fuel cell, comprising: a cooling duct. 2. The LTS catalyst layer cooling duct is provided with a groove in the circumferential direction of the two LTS catalyst layer partition plates, and the two LTS catalyst layer partition plates face each other to form a hermetic seal. 2. The fuel cell reactor according to claim 1, wherein the cooling channel is formed as a single cooling passage. 3. The LTS catalyst layer cooling duct is characterized in that the cross-sectional area of the flow passage is reduced up to the middle of the cooling flow passage, and the cross-sectional area of the flow passage is increased before the vicinity of a point where the cooling medium evaporates. The fuel cell reactor according to claim 2. 4. A hydrogen contributing to a high temperature reaction for removing carbon monoxide from the steam reforming gas is provided at a central portion of the desulfurization catalyst layer housed in a central portion cylinder of the reactor body.
Forming a TS catalyst layer, separating the desulfurization catalyst layer and the HTS catalyst layer with a cylindrical catalyst layer partition plate, guiding the raw material gas to the desulfurization catalyst layer and heating the raw material gas in the process. A raw material gas heating duct is formed in the catalyst layer partition plate, and the HTS catalyst layer is concentrically formed into a cylindrical HTS.
HT for partitioning by a catalyst layer partition plate and passing cooling water for cooling the HTS catalyst layer through the HTS catalyst layer partition plate
Forming an S catalyst layer cooling duct, guiding the reformed gas that has passed through the HTS catalyst layer to the LTS catalyst layer, and heating the desulfurization catalyst layer heating duct for heating the desulfurization catalyst layer in the process; The fuel cell reactor according to claim 1, wherein the reactor is provided on a cylindrical side wall of the fuel cell. 5. The raw material gas heating duct, the HTS catalyst layer cooling duct, or the desulfurization catalyst layer heating duct,
A groove is provided in the circumferential direction of the two partition plates, and the groove of the two partition plates faces each other, and is formed by hermetically joining together to form one communicating channel. Item 6. A fuel cell reactor according to item 4. 6. A plurality of small-diameter heat transfer tubes having a small diameter are provided inside the desulfurization catalyst layer housed in a central cylinder of the reactor body, and the HTS catalyst layer is filled inside the heat transfer tubes. 2. A water cooling pipe through which cooling water for cooling the HTS catalyst layer is provided.
A reactor for a fuel cell according to claim 1. 7. A steam reforming gas containing carbon monoxide and steam is produced by desulfurizing the raw material gas through a desulfurization catalyst, mixing steam with an ejector and reforming with a reformer. In a fuel cell reactor in which the carbon monoxide contained in the gas is reduced to obtain a hydrogen-rich reformed gas, a reaction for removing a sulfur compound from the raw material gas formed in a cylindrical vessel having a large diameter is performed. A reactor body containing a contributing desulfurization catalyst layer, a small-diameter heat transfer tube having a double-pipe configuration arranged in plural inside the reactor body, and a steam reforming gas stored above the heat transfer tube. An HTS catalyst layer that contributes to a high-temperature reaction for removing carbon monoxide, and an LTS that is housed under the heat transfer tube and contributes to a low-temperature reaction for removing carbon monoxide from the steam reformed gas. A catalyst layer, A helical spacer is installed between a water cooling pipe provided inside the heat transfer pipe and through which cooling water for cooling the HTS catalyst layer and the LTS catalyst layer passes, and a pipe wall of the double pipe heat transfer pipe. A raw material gas heating duct for guiding the raw material gas to the desulfurization catalyst layer and heating the raw material gas in the process, and guiding the steam reformed gas to the heat transfer tube and forming the desulfurization catalyst in the process. A reactor for a fuel cell, comprising: a desulfurization catalyst layer heating duct for heating a layer.