JP5329944B2 - Steam reformer for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a steam reforming device in which various problems in a conventional steam reformer are solved and cost reduction is promoted. <P>SOLUTION: The steam reforming device for a fuel cell includes a cylindrical steam reformer which is equipped with a plurality of cylindrical bodies consisting of a first cylindrical body, a second cylindrical body, and a third cylindrical body with sequentially larger diameters coaxially arranged leaving spacings in between, and a burner in the center part of the circumferential direction of the first cylindrical body in which the upper part gap out of the gaps partitioned by the first cylindrical body and the second cylindrical body in the circumferential direction is used as a pre-heating layer of a mixture flow of raw material fuel and raw material water, and equipped with a reforming catalyst layer in the lower part gap, and a cylindrical steam reformer in which a reforming gas flow passage is constituted that is reversed at the lower end of the second cylindrical body in the gap partitioned in the circumferential direction by the second cylindrical body and the third cylindrical body, a CO denatured catalyst layer at the upper part in the cylindrical body, a CO removing catalyst layer at the lower part, an air supply part between the CO denatured catalyst layer and the CO removing catalyst layer, and a cylindrical reforming gas treatment device arranged with raw material water preheating tubes to supply the water to the preheating layer of the steam reformer in the outer periphery where the CO removing catalyst layer is positioned out of the cylindrical bodies are included. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a steam reformer and a cylindrical type for a fuel cell including a reformed gas processor for removing CO in reformed gas generated by the steam reformer separately from the steam reformer. The present invention relates to a steam reformer.

  As a method for producing fuel hydrogen in a polymer electrolyte fuel cell (PEFC), a steam reforming method for raw fuel is known. In the steam reforming method, a steam reformer is used.

  In this specification, the fuel supplied to the steam reformer for reforming is referred to as “raw fuel”. As raw fuel, methane, ethane, propane, butane, pentane, city gas, LP gas (liquefied petroleum gas), natural gas, gasoline, kerosene, and other hydrocarbons (including mixtures of two or more hydrocarbons) are used. Is done. Alcohols and ethers may be mixed with them.

  FIG. 5 is a diagram illustrating a system from raw fuel processing to PEFC. The steam reformer is generally composed of a combustion part (heating part) in which a burner or a combustion catalyst is arranged, and a reforming part in which a reforming catalyst such as Ni-based or Ru-based is arranged. In the reforming section, the raw fuel is reacted with steam to generate hydrogen-rich reformed gas. Since the reaction occurring in the reforming part involves a large endotherm, heat from the outside is necessary for the progress of the reaction, and a temperature of about 400 to 680 ° C. is necessary. The steady operation is set to 660 ° C., for example. For this reason, combustion heat (ΔH) generated by combustion of fuel gas with air in the combustion section is supplied to the reforming section.

  Sulfur compounds are added to city gas and LP gas as odorants for the purpose of leakage protection, and gasoline and kerosene contain trace amounts of sulfur compounds that could not be desulfurized by the refining process from crude oil. ing. Since the reforming catalyst is poisoned by these sulfur compounds and causes performance deterioration, the raw fuel is introduced into the desulfurizer in order to remove those sulfur compounds. Next, steam from a steam generator provided separately is mixed and introduced into the steam reformer, and a hydrogen-rich reformed gas is generated by the reforming reaction of the raw fuel with steam in the steam reformer. .

The reforming reaction when the raw fuel is methane, for example, is represented by “CH ₄ + 2H ₂ O → CO ₂ + 4H ₂ ”. In the reformed gas to be generated, in addition to unreacted methane, unreacted water vapor, carbon dioxide (CO ₂ ), carbon monoxide (CO) is by-produced, and 8 to 15% (capacity%, the same for% below) ) Degree included. The CO content in the fuel hydrogen supplied to the PEFC is limited to about 100 ppm (capacity ppm, the same applies to the following ppm), and if it exceeds this, the cell performance is significantly deteriorated, so the CO component can be formed before being introduced into the PEFC. As long as it is necessary to remove.

For this reason, the reformed gas is introduced into a CO converter in order to convert by-product CO into carbon dioxide and remove it. In the CO converter, a catalyst such as a copper-zinc system or a platinum catalyst is used, but a temperature of about 220 to 300 ° C. (some catalysts have an appropriate temperature of about 200 to 250 ° C.) is necessary to make the catalyst function. . The reaction in the CO converter is represented by “CO + H ₂ O → CO ₂ + H ₂ ”, and unreacted residual steam is utilized in the steam reformer as the steam necessary for this reaction.
Note that the temperature at which the CO conversion catalyst functions is its effective operating temperature, but in this specification, the term “appropriate temperature” is used as appropriate.

  The reformed gas exiting from the CO converter mainly consists of hydrogen and carbon dioxide except for unreacted methane and excess steam. Of these, hydrogen is an intended component, but the reformed gas obtained through the CO converter also does not completely remove CO, but contains a trace amount of CO. For this reason, the reformed gas is introduced into the CO oxidizer after the CO concentration is lowered to about 1% or less by the CO converter.

In the CO remover, an oxidant gas such as air is added to the reformed gas that has passed through the CO converter, and CO is reduced to about 100 ppm or less, preferably 50 ppm or less by a selective oxidation reaction of CO (CO + 1 / 2O ₂ = CO ₂ ). More preferably, it is reduced to 10 ppm or less. The operating temperature of the CO remover is about 130 to 170 ° C. (There are also catalysts having an appropriate temperature of 100 to 150 ° C. for the CO removal catalyst). The purified hydrogen is supplied to the fuel electrode of PEFC.

  In the conventional system, the steam reformer, the CO converter, and the CO remover are separately installed as described above. However, in such a system, the heat dissipation loss is large, so that the efficiency is lowered. Met.

  Therefore, a multi-cylinder steam reformer has been developed in which a CO reformer and a CO remover are integrated into a steam reformer using multiple tubes (Patent Documents 1 to 4, etc.).

WO 02/098790 A1 WO 03/078311 A1 JP 2002-187705 A JP 2006-232611 A

  FIG. 6 is a diagram for explaining an example of such a multi-cylinder steam reformer integrated. As shown in FIG. 6, a plurality of cylindrical bodies composed of a first cylindrical body 101, a second cylindrical body 102, and a third cylindrical body 103, which are arranged concentrically at intervals and which have large diameters (diameters, hereinafter the same), A burner 107 disposed at the center in the circumferential direction of the first cylindrical body 101, and a preheating layer 114 and a reforming catalyst layer 116 are provided in a gap partitioned in the circumferential direction by the first cylindrical body 101 and the second cylindrical body 102. Yes. In the preheating layer 114, rods 115 are spirally arranged therein, and a continuous spiral gas passage is formed therein. A reformed gas flow path 120 that is inverted at the lower end of the second cylindrical body 102 is formed in a gap partitioned in the circumferential direction by the second cylindrical body 102 and the third cylindrical body 103.

  Some types of multi-cylinder steam reformers of this type have a structure in which radiation tubes are arranged at intervals inside the first cylindrical body 101. FIG. 6 shows this aspect. The radiation tube 106 is attached to the upper lid / burner mounting base 108 so that the lower end thereof is spaced from the bottom plate 109 of the first cylindrical body 101. Combustion gas in the burner 107 descends in the combustion chamber F, turns back at the lower end of the radiant cylinder 106, passes through the combustion gas passage 110, and is discharged from the upper portion of the combustion exhaust gas exhaust pipe 142.

  Between the fourth cylindrical body 104 and the second cylindrical body 102 following the third cylindrical body 103, the CO shift catalyst layer 123 and the CO removal catalyst layer 131 are sequentially arranged and integrated, following the reformed gas flow path 120. It becomes. That is, by sequentially placing the CO conversion catalyst layer 123 and the CO removal catalyst layer 131 after the reforming catalyst layer 116 between the fourth cylinder 104 and the second cylinder 112 following the third cylinder 103. Composed.

  A fourth cylinder 104 having a diameter larger than that of the third cylinder 103 is disposed on the third cylinder 103, and a CO shift catalyst layer 123 is provided between the second cylinder 102 and the fourth cylinder 104. . A plate body 121 is disposed between the upper end portion of the third cylindrical body 103 and the lower end portion of the fourth cylindrical body 104. A support plate 122 having a plurality of holes for gas circulation is disposed on the plate body 121 at intervals, a CO conversion catalyst layer 123 is disposed on the support plate 122, and a gas is formed on the CO conversion catalyst layer 123. A partition plate 124 having a plurality of holes for distribution is disposed. A plate body 126 is disposed between the outer periphery of the second cylindrical body 102 and the fourth cylindrical body 104 with a space from the partition plate 124.

  The plate 121 is a donut-shaped plate because the portion corresponding to the diameter of the third cylinder 103 is occupied by the third cylinder 103, and the support plate 121, the partition plate 124, and the plate 126 A portion corresponding to the diameter of the three cylindrical body 103 is occupied by the third cylindrical body 103, and thus is a donut-shaped plate. The support plate 122 and the partition plate 124 may be formed of a mesh body made of metal or the like. In this case, the mesh body of the mesh body serves as a gas flow hole. The reformed gas that has flowed through the reformed gas flow path 20 is supplied to the CO shift catalyst layer 123 through a large number of holes provided in the support plate 122.

  Following the CO shift catalyst layer 123, a CO removal catalyst layer 131 is disposed between the fifth cylinder 105 and the second cylinder 102 following the fourth cylinder 104. The CO removal catalyst layer 131 may be disposed between the second cylindrical body 102 and the fourth cylindrical body 104. In this case, the fifth cylinder 105 is not necessary, and the CO removal air supply pipe 144 is disposed on the side of the fourth cylinder 104.

  In the preheating layer 14, the rod 15 is disposed in a spiral shape, whereby a continuous spiral gas passage is formed in the preheating layer 14. A mixed stream of raw fuel and water and / or steam is supplied to the preheating layer 114 to heat the mixed stream. In the case of water, it is heated and vaporized, and further heated. The mixed flow of raw fuel and steam heated in the preheating layer 114 is introduced into the reforming catalyst layer 116, and reformed gas is generated by the reforming reaction here. The reformed gas flows into the reformed gas channel 20 and is taken out from the conduit 145 through the CO shift catalyst layer 123 and the CO removal catalyst layer 131.

  When assembling this type of multi-cylinder steam reformer, the first cylinder 101 and the bottom plate 109, the third cylinder 103 and the bottom plate 119, the third cylinder 103 and the plate body 121, the plate body 121, and the like. Between the fourth cylinder 104, between the second cylinder 102 and the support plate 122, the partition plate 124, the plate body 126, and the plate body 128, between the fourth cylinder 104 and the support plate 122, the partition plate 124, and the plate body It is necessary to weld at a number of locations such as 126 and the plate 128.

  By the way, in order to put this integrated multi-cylinder steam reformer into practical use, for example, as shown in FIG. 6, the burner is disposed at the center of the first cylindrical body, and the gas to be reformed. In view of the flow direction of the raw fuel, it is necessary to arrange the reforming catalyst layer → the CO conversion catalyst layer → the CO removal catalyst layer in the vertical direction or the vertical direction.

  In order to maintain the performance required for the reformer design life of the reformer catalyst layer, the CO conversion catalyst layer, and the CO removal catalyst layer, the appropriate amount must be filled therein. However, among these three types of catalysts, the amount of the CO conversion catalyst tends to increase. In order to increase the amount of the CO shift catalyst, as shown in FIG. 6, the tube diameter of the CO shift catalyst layer is particularly large when the filling region is expanded in the circumferential direction, that is, in the direction perpendicular to the vertical axis direction. As a result, the length of the weld line when assembling the CO shift catalyst layer is increased, and the manufacturing cost is increased.

  On the other hand, it is possible to produce hydrogen by filling each independent cylindrical tube with each of these catalysts and connecting each cylindrical tube with a pipe, but since the surface area is large, the heat dissipation loss is large. Had problems in terms of efficiency and startability.

  The present invention relates to a system in which a conventional steam reformer, a CO converter and a CO remover are separately installed, and a multi-cylinder steam reformer in which the conventional CO converter and the CO remover are integrated. A fuel comprising a steam reformer and a reformed gas processor for removing CO in the reformed gas produced by the steam reformer separately from the steam reformer, which solves the problem An object of the present invention is to provide a cylindrical steam reformer for a battery.

The present invention (1) is a fuel cell steam reformer comprising a cylindrical steam reformer and a cylindrical reformed gas processor separately,
The cylindrical steam reformer is
(A) a plurality of first and second cylindrical bodies, each of which is arranged concentrically and spaced apart from each other, and has an upper end at a central portion in the circumferential direction of the first cylindrical body; With a burner arranged from
(B) Of the gaps defined in the circumferential direction by the first cylinder and the second cylinder, the upper gap is used as a preheating layer for the mixed flow of raw fuel and raw water, and the lower gap is modified. With a catalyst layer,
(C) comprising a reformed gas flow channel that is inverted at the lower end of the second cylindrical body in a gap partitioned in the circumferential direction by the second cylindrical body and the third cylindrical body;
The cylindrical reformed gas processor is
(A) a cylinder is provided with a CO shift catalyst layer at the top, a CO removal catalyst layer at the bottom, and an air supply unit between the CO shift catalyst layer and the CO removal catalyst layer;
(B) A raw water preheating pipe to be supplied to the preheating layer of the steam reformer is disposed on the outer periphery of the cylindrical body where the CO removal catalyst layer is located,
The fuel cell steam reformer is characterized in that a reformed gas conduit is disposed between the reformed gas flow path of the cylindrical steam reformer and the CO shift catalyst layer.
The present invention (1) is a reference invention.

The present invention (2) is a fuel cell steam reformer comprising a cylindrical steam reformer and a cylindrical reformed gas processor separately,
The cylindrical steam reformer is
(A) a plurality of first and second cylindrical bodies, each of which is arranged concentrically and spaced apart from each other, and has an upper end at a central portion in the circumferential direction of the first cylindrical body; With a burner arranged from
(B) Of the gaps defined in the circumferential direction by the first cylinder and the second cylinder, the upper gap is used as a preheating layer for the mixed flow of raw fuel and raw water, and the lower gap is modified. With a catalyst layer,
(C) comprising a reformed gas flow channel that is inverted at the lower end of the second cylindrical body in a gap partitioned in the circumferential direction by the second cylindrical body and the third cylindrical body;
The cylindrical reformed gas processor is
(A) A fifth cylinder having a diameter larger than that of the fourth cylinder and the fourth cylinder and a lower outer circumference of the fourth cylinder are arranged concentrically at intervals.
(B) While disposing a CO shift catalyst layer in the fourth cylinder, a CO removal catalyst layer is provided between the fourth cylinder and the fifth cylinder,
(C) An air supply unit is provided between the CO conversion catalyst layer and the CO removal catalyst layer, and a raw water preheating pipe is disposed on the outer periphery of the CO removal catalyst layer,
The fuel cell steam reformer is characterized in that a reformed gas conduit is disposed between the reformed gas flow path of the cylindrical steam reformer and the CO shift catalyst layer.
The present invention (2) is a reference invention.

The present invention (3) is a steam reformer for a fuel cell comprising a cylindrical steam reformer and a cylindrical reformed gas processor separately,
The cylindrical steam reformer is
(A) a plurality of first and second cylindrical bodies, each of which is arranged concentrically and spaced apart from each other, and has an upper end at a central portion in the circumferential direction of the first cylindrical body; With a burner arranged from
(B) Of the gaps defined in the circumferential direction by the first cylinder and the second cylinder, the upper gap is used as a preheating layer for the mixed flow of raw fuel and raw water, and the lower gap is modified. With a catalyst layer,
(C) comprising a reformed gas flow channel that is inverted at the lower end of the second cylindrical body in a gap partitioned in the circumferential direction by the second cylindrical body and the third cylindrical body;
The cylindrical reformed gas processor is
(A) A fifth cylinder having a diameter larger than the outer circumference of the fourth cylinder and a fourth cylinder having a diameter larger than the outer circumference of the fourth cylinder is spaced apart from the outer circumference of the lower position of the fourth cylinder. A sixth cylinder having a larger diameter than the outer periphery of the fifth cylinder is arranged at an interval on the outer periphery of the five cylinder,
(B) A CO shift catalyst layer is disposed in the fourth cylinder, and a CO removal catalyst layer is provided between the fifth cylinder and the sixth cylinder,
(C) From the lower part of the CO conversion catalyst layer toward the CO removal catalyst layer, a CO-modified reformed gas circulation part that has passed through the CO conversion catalyst layer is provided, and an air supply pipe is disposed in the circulation part, (D) A raw water preheating pipe is disposed on the outer periphery of the sixth cylindrical body,
The fuel cell steam reformer is characterized in that a reformed gas conduit is disposed between the reformed gas flow path of the cylindrical steam reformer and the CO shift catalyst layer.
The present invention (3) is the invention according to claim 1.

  In the fuel cell steam reformer of the present invention (3), an electric heater can be disposed on the outer periphery of the fourth cylindrical body between the fourth cylindrical body and the fifth cylindrical body.

  In the cylindrical steam reformer for a fuel cell of the present invention (1) to (3), a radiation cylinder may be provided inside the first cylindrical body in the steam reformer.

According to the fuel cell steam reformer of the present invention, the following effects (a) to (d) can be obtained.
(A) The heat dissipation loss can be greatly reduced with respect to a system in which a conventional steam reformer, CO converter, and CO remover are separately installed.
(B) A heat efficiency substantially equivalent to that of a multi-cylinder steam reformer in which a conventional CO converter and CO remover are integrated can be achieved.
(C) As described above, among the reforming catalyst, the CO shift catalyst, and the CO removal catalyst layer, the amount of the CO shift catalyst tends to increase. In order to increase it, the pipe diameter of the CO shift catalyst layer becomes large. As a result, the length of the weld line when assembling the CO shift catalyst layer is increased and the manufacturing cost is increased. However, in the present invention, since the pipe diameter of the CO shift catalyst layer can be further reduced, This can reduce the risk of defects in this portion, such as reducing the length of the weld line and reducing the length of the weld line, and can simplify the production process of the steam reformer.
(D) As a result of (a) to (c), cost reduction can be achieved.

  A cylindrical steam reformer for a fuel cell according to the present invention includes a cylindrical steam reformer that reforms raw fuel to produce a hydrogen-rich reformed gas, and a cylinder that removes by-product CO from the reformed gas. In order to make effective use of heat generated by the cylindrical steam reformer and heat generated by the cylindrical reformed gas processor, the basic structure is to separately provide the type reformed gas processor. Device.

  Hereinafter, although embodiment of this invention (1)-(3) is demonstrated sequentially, the matter common to this invention (1)-(3) is mainly demonstrated in the location of this invention (1).

<Embodiment of the present invention (1)>
The present invention (1) is a steam reformer for a fuel cell comprising a cylindrical steam reformer and a cylindrical reformed gas processor separately. And
The cylindrical steam reformer includes: (a) a plurality of first and second cylindrical bodies, each having a large diameter, arranged concentrically and spaced apart; A burner disposed from the upper end at the center in the circumferential direction of the cylindrical body, and (b) of the gaps partitioned in the circumferential direction by the first cylindrical body and the second cylindrical body, the upper gap is used as a raw fuel and a raw material. A preheating layer of a mixed flow with water, a reforming catalyst layer provided in a lower gap, and (c) the second cylinder in a gap partitioned in the circumferential direction by the second cylinder and the third cylinder Comprising a reformed gas flow channel inverted at the lower end of the body,
The cylindrical reformed gas processor comprises (a) a CO conversion catalyst layer in the upper part of the cylindrical body, a CO removal catalyst layer in the lower part, and air between the CO conversion catalyst layer and the CO removal catalyst layer. (B) a raw material water preheating pipe to be supplied to the preheating layer of the steam reformer is disposed on the outer periphery of the cylindrical body where the CO removal catalyst layer is located.
In addition, a reformed gas conduit is disposed between the reformed gas flow path of the cylindrical steam reformer and the CO shift catalyst layer.

  FIG. 1 is a diagram for explaining the present invention (1). As shown in FIG. 1, the fuel cell steam reformer of the present invention (1) includes a cylindrical steam reformer R and a cylindrical reformed gas processor A separately.

<About the cylindrical steam reformer R>
The cylindrical steam reformer R arranges the first cylindrical body 1, the second cylindrical body 2, and the third cylindrical body 3 with sequentially increasing diameters. A burner 6 is arranged from the upper end at the center in the circumferential direction of the first cylinder 1 among the plurality of cylinders. The burner 6 is installed and fixed to the upper lid / burner mounting member 7. A bottom plate 5 is disposed at the lower end of the first cylindrical body 1. The bottom plate 5 is a disk having a diameter corresponding to the diameter of the first cylindrical body 1. A space surrounded by the upper lid / burner mounting member 7, the first cylindrical body 1, and the bottom plate 5 is a combustion chamber F including the burner 6.

  A bottom plate 15 is disposed at the lower end of the third cylindrical body 3. The bottom plate 15 is a disk having a diameter corresponding to the diameter of the third cylindrical body 3. The lower end of the second cylindrical body 2 is disposed so as to be spaced from the bottom plate 15. Further, the bottom plate 15 has a gap between the bottom plate 5. By making the bottom plate 5 have a gap with respect to the bottom plate 55, the first cylindrical body 1 and the third cylindrical body 1 due to the difference in thermal expansion between the first cylindrical body 1, the third cylindrical body 3 and the bottom plate 15 at the time of operation. Distortion and destruction between the cylindrical body 3 and the bottom plate 15 can be prevented.

  Of the gaps defined by the first cylinder 1 and the second cylinder 2 in the circumferential direction, the upper gap is used as the preheating layer 10 of the mixed flow of raw fuel and raw water, and the lower gap is used as the reforming catalyst layer 13. And A raw fuel supply pipe 40 and a water vapor supply pipe 39 are disposed on the preheating layer 10. A spiral flow path is configured by arranging a metal bar 11 such as a round bar in a spiral between the first cylinder 1 and the second cylinder 2 constituting the preheating layer 10.

  The reforming catalyst layer 13 subsequent to the preheating layer 10 is configured by disposing a porous plate 12 in the upper portion thereof, disposing a porous support plate 14 in the lower portion thereof, and filling the reforming catalyst therebetween. The perforated plate 12 and the perforated support plate 14 are disk-like perforated plates because the inner circumference is occupied by the first cylindrical body 1 and the outer circumference is occupied by the second cylindrical body 2. The perforated plate 12 and the support plate 14 may be formed of a metal mesh (= metal mesh) or the like.

  A reformed gas flow path 16 is formed in a gap defined by the second cylindrical body 2 and the third cylindrical body 3 in the circumferential direction. A reformed gas outlet pipe 17 is provided above the reformed gas channel 16. Since the lower end of the second cylindrical body 2 is disposed at a distance from the bottom plate 15, the reformed gas generated in the reforming catalyst layer 13 is reversed at the lower end of the second cylindrical body 2 and the reformed gas flow After flowing into the channel 16 and flowing upward in the reformed gas channel 16, the gas is led out from the reformed gas outlet pipe 17. The reformed gas outlet pipe 17 is also referred to as a reformed gas conduit in connection with a cylindrical reformed gas processor.

  When the cylindrical steam reformer R is operated, the fuel gas generated in the burner 6 is folded inside the bottom plate 5 as indicated by an arrow in the combustion chamber F, and the inside of the first cylindrical body 1 is moved upward. It flows toward. Meanwhile, the fuel gas sequentially heats the reformed catalyst of the reforming catalyst layer 13, the raw fuel flowing through the reforming catalyst layer 13 and the steam mixed gas through the first cylindrical body, and the raw fuel flowing through the preheating layer 10. The mixed gas of water vapor is heated and discharged from the combustion exhaust gas discharge pipe 8.

  The raw fuel and water vapor are respectively introduced into the preheating layer 10 through the raw fuel supply pipe 40 and the water vapor supply pipe 39 and heated to a temperature of about 400 ° C. or higher, and then the reforming catalyst following the preheating layer 10. Introduced into layer 13. The reforming catalyst layer 13 generates hydrogen-rich reformed gas by the reforming reaction of the raw fuel with water vapor. The generated reformed gas is inverted at the lower end of the second cylindrical body 2 and flows into the reformed gas channel 16, flows upward in the channel 16, and is led out from the reformed gas outlet pipe 17. The derived reformed gas is sent to a cylindrical reformed gas processor A that is configured and arranged separately from the cylindrical steam reformer R.

  In the cylindrical steam reformer R, a radiation cylinder can be provided inside the first cylindrical body 1 with a space from the first cylindrical body 1. In FIG. 2, the radiation tube 4 is disposed as indicated by reference numeral 4. The radiation tube 4 is disposed from the lower surface of the upper lid / burner mounting member 7, and the lower end thereof is disposed with a space between the bottom plate 5 disposed at the lower end of the first cylindrical body 1.

  When the cylindrical steam reformer R provided with the radiation cylinder is operated, the fuel gas generated in the burner 6 is folded back at the lower end of the radiation cylinder 4 and is directed upward between the radiation cylinder 4 and the first cylindrical body 1. Flowing. Meanwhile, the fuel gas sequentially heats the reformed catalyst of the reforming catalyst layer 13, the raw fuel flowing through the reforming catalyst layer 13 and the steam mixed gas through the first cylindrical body, and the raw fuel flowing through the preheating layer 10. The mixed gas of water vapor is heated and discharged from the combustion exhaust gas discharge pipe 8.

  The structure in which the radiation cylinder 4 is provided in this manner can be similarly applied to the cylindrical steam reformer R of the present inventions (2) to (3).

<About the cylindrical reformed gas processor A>
As shown in FIG. 1 as a cylindrical reformed gas processor A, the cylindrical reformed gas processor A is configured separately from the cylindrical steam reformer and is juxtaposed with the cylindrical steam reformer. The cylindrical reformed gas processor A includes a cylindrical body 19, and the inside of the cylindrical body 19 includes a CO conversion catalyst layer 23 at an upper portion and a CO removal catalyst layer 32 at a lower portion. An air supply unit 50 is provided between the CO shift catalyst layer 23 and the CO removal catalyst layer 32. An upper lid 18 is provided at the upper end of the cylindrical body 19, and the reformed gas outlet pipe 17 from the cylindrical steam reformer R is connected to the upper lid 18, and the outlet pipe 17 is opened.

  The distribution plate 20, the porous plate 22, the porous plate 24, the distribution plates 25, 27, 29, the porous plate 31, the porous plate 33, the distribution plate 34, and the lower lid 36 are sequentially arranged at a distance from the upper lid 18. Each of these plate bodies is a disk-shaped plate body having a diameter corresponding to the inner diameter of the cylindrical body 19. The CO shift catalyst layer 23 is configured by filling a CO shift catalyst between the porous plate 22 and the porous plate 24. The perforated plate 24 has a large number of holes, supports the CO conversion catalyst, and plays a role of flowing out the CO converted reformed gas in the CO conversion catalyst layer. The perforated plates 22, 24, 31, and 33 may be made of a metal mesh or the like.

The distribution plate 20 has a plurality of communication holes as indicated by reference numeral 21 in FIG. FIG. 1 shows an example in which a plurality of communication holes 21 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By providing a plurality of communication holes 21 equally, the reformed gas introduced into the gap between the upper lid 18 and the distribution plate 20 serves to evenly flow toward the CO shift catalyst layer 23. In order to make the catalyst layer temperature distribution uniform, the distribution plate 20 is provided with a plurality of communication holes 21 so that the gas hardly flows and the temperature tends to decrease due to heat dissipation so that a large amount of gas flows, thereby distributing the gas. Then, it is more preferable. The reformed gas that has passed through the distribution plate 20 flows into the CO shift catalyst layer 23 via the perforated plate 22 and changes CO in the reformed gas to CO ₂ by the CO shift reaction in the CO shift catalyst, and H ₂ is also added. Generate.

  The reformed gas that has undergone CO conversion in the CO conversion catalyst layer 23 flows into the gap between the distribution plate 25 and the distribution plate 27 through the perforated plate 24 and the distribution plate 25. The distribution plate 25 has a plurality of communication holes as indicated by reference numeral 26 in FIG. FIG. 1 shows an example in which a plurality of communication holes 26 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By uniformly providing a plurality of communication holes 26, the CO-modified reformed gas that has flowed into the gap between the porous plate 24 and the distribution plate 25 is directed toward the gap between the distribution plate 25 and the distribution plate 27. It plays the role of evenly flowing. The distribution plate 27 is provided with a hole 28 at the center thereof.

  In the cylindrical tube 19, an air introduction pipe 41 is arranged at a portion where a gap formed by the distribution plate 25 and the distribution plate 27 is located. Configure. The tip of the air introduction pipe 41 is opened in the gap. The CO-modified reformed gas flows into the gap formed by the distribution plate 25 and the distribution plate 27, and the air from the air introduction pipe 41 is mixed with the inflowing reformed gas.

  As described above, the air supply unit 50 serves to supply air to the CO-modified reformed gas and to mix both gases. In the example shown in FIG. In this example, a plurality of communication holes 26 are provided at equal intervals from the center of the disc-shaped plate body and at equal intervals in the circumferential direction, and holes 28 are provided at the center of the distribution plate 27. It can be carried out in various modes such as providing a large number of communication holes at equal intervals on the entire surface.

  A distribution plate 29 is disposed at a lower portion of the distribution plate 27, and a distribution plate 29 is disposed at a lower portion of the distribution plate 29. The distribution plate 27 has a plurality of communication holes as indicated by reference numeral 30 in FIG. FIG. 1 shows an example in which a plurality of communication holes 30 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By uniformly providing a plurality of communication holes 30, the mixed flow of the CO-modified reformed gas and air introduced into the gap between the distribution plate 27 and the distribution plate 29 is directed toward the CO removal catalyst layer 32. It plays a role to flow into. In order to make the catalyst layer temperature distribution uniform, a plurality of communication holes 30 are provided in the distribution plate 29 so that the gas hardly flows and the gas tends to decrease due to heat dissipation, and the gas is distributed. Then, it is more preferable.

The CO removal catalyst layer 32 is configured by filling a CO removal catalyst between the porous plate 31 and the porous plate 33. The mixed flow that has passed through the distribution plate 29 flows into the CO removal catalyst layer 32 through the porous plate 31, and converts CO in the CO-modified reformed gas into CO ₂ by selective oxidation of CO in the CO removal catalyst. To further reduce the CO concentration. The reformed gas in which CO is further reduced by the CO removal catalyst layer 32 is led out from the reformed gas (CO removed) take-out pipe 42 through the perforated plate 33 and the distribution plate 34, and is supplied to the fuel electrode of the PEFC.

<Regarding the preheating pipe for raw water>
A spiral preheating tube 38 of raw material water is disposed on the outer periphery of the cylindrical body 19 where the CO removal catalyst layer 32 is located. Although a spiral preheating tube is shown in the figure, a water cooling jacket or the like can be applied as appropriate. During the operation of the steam reformer for a fuel cell of the present invention (1), the raw water supplied from the water supply pipe 37 is heated while flowing in the preheating pipe 38 and is heated by the heat generated in the CO removal catalyst layer 32. . In the figure, the heat recovery unit is configured only around the CO removal catalyst. However, the heat recovery unit around the CO removal catalyst layer is also provided around the shift catalyst layer so that the catalyst layer temperature is appropriate. The heat recovery part may be formed in communication with the heat recovery part. Steam generated by heating is supplied to the preheating layer 10 in the cylindrical steam reformer R through a conduit 39.

  By adopting such a structure in which the raw water preheating pipe 38 is disposed on the outer periphery where the CO removal catalyst layer 32 is located, the raw water supplied to the preheating layer 10 in the cylindrical steam reformer R is supplied to the cylindrical reformed gas. The surplus heat generated in the processor A is preliminarily heated, and the heat generated in the system including the cylindrical steam reformer R and the cylindrical reformed gas processor A can be effectively used.

  In the steam reforming apparatus of the present invention (1), either or both of the cylindrical steam reformer and the cylindrical reformed gas processor are used upside down. The same applies to the steam reforming apparatuses of the present inventions (2) to (3). In this case, for example, the upper lid / burner mounting base 7 becomes the lower lid / burner mounting base 7, the bottom plate 5 becomes the upper plate 5, the upper lid 18 becomes the lower lid 18, and the lower lid 36. Becomes the upper lid 36.

<Embodiment of the present invention (2)>
The present invention (2) is a steam reformer for a fuel cell comprising a cylindrical steam reformer and a cylindrical reformed gas processor separately. And
The cylindrical steam reformer includes: (a) a plurality of first and second cylindrical bodies, each having a large diameter, arranged concentrically and spaced apart; A burner disposed from the upper end at the center in the circumferential direction of the cylindrical body, and (b) of the gaps partitioned in the circumferential direction by the first cylindrical body and the second cylindrical body, the upper gap is used as a raw fuel and a raw material. A preheating layer of a mixed flow with water, a reforming catalyst layer provided in a lower gap, and (c) the second cylinder in a gap partitioned in the circumferential direction by the second cylinder and the third cylinder Comprising a reformed gas flow channel inverted at the lower end of the body,
In the cylindrical reformed gas processor, (a) a fourth cylindrical body and a fifth cylindrical body having a diameter larger than that of the fourth cylindrical body are concentrically arranged on the lower outer periphery of the fourth cylindrical body. (B) a CO oxidation catalyst layer is disposed in the fourth cylinder, and a CO removal catalyst layer is provided between the fourth cylinder and the fifth cylinder, and (c) the CO An air supply unit is provided between the shift catalyst layer and the CO removal catalyst layer, and a raw water preheating pipe is disposed on the outer periphery of the CO removal catalyst layer.
In addition, a reformed gas conduit is disposed between the reformed gas flow path of the cylindrical steam reformer and the CO shift catalyst layer.

  FIG. 3 is a diagram for explaining the present invention (2). FIG. 3 shows a structure in which the radiant cylinder 4 is provided in the cylindrical steam reformer R, but the structure in which the radiant cylinder 4 is not provided is the same as the cylindrical steam reformer R of the present invention (1). It is.

  As shown in FIG. 3, the fuel cell steam reformer of the present invention (2) includes a cylindrical steam reformer R and a cylindrical reformed gas processor B separately. Among them, the cylindrical steam reformer R is the same as the cylindrical steam reformer R in the embodiment of the present invention (1).

<About the cylindrical reformed gas processor B>
In FIG. 3, as shown as a cylindrical reformed gas processor: B, the cylindrical reformed gas processor B is configured separately from the cylindrical steam reformer R and juxtaposed with the cylindrical steam reformer. . The cylindrical reformed gas processor B has a fourth cylinder 201 and a fifth cylinder 203 having a diameter larger than that of the fourth cylinder 201 concentrically on the outer periphery of the lower part of the outer periphery of the fourth cylinder 201. Place them at intervals.

  An upper lid 200 is provided at the upper end of the fourth cylindrical body 201, and the reformed gas outlet pipe 17 from the cylindrical steam reformer R is connected to the upper lid 200, and the outlet pipe 17 is opened. In the fourth cylindrical body 201, a distribution plate 205, a porous plate 207, a porous plate 209, and a distribution plate 210 are sequentially arranged with a distance from the upper lid 200. Each of these plate bodies is a disk-shaped plate body having a diameter corresponding to the inner diameter of the fourth cylindrical body 201.

  The fourth cylinder 201 is provided with a CO shift catalyst layer 208, and the CO removal catalyst layer 216 is provided between the fourth cylinder 201 and the fifth cylinder 203. The CO shift catalyst layer 208 and the CO removal catalyst layer 216 are provided. An air supply unit is provided in the lower part of the. The air supply unit is configured between the lower part of the CO shift catalyst layer 208 and the CO removal catalyst layer 216 and the lower lid 204 common to the fourth cylindrical body 201 and the fifth cylindrical body 203.

  More specifically, the CO shift catalyst layer 208 is configured by filling a CO shift catalyst between the porous plate 207 and the porous plate 209. The perforated plate 209 has a large number of holes, supports the CO conversion catalyst, and plays a role of flowing out the CO converted reformed gas in the CO conversion catalyst layer. The perforated plates 207 and 209 may be made of a metal mesh or the like.

The distribution plate 205 has a plurality of communication holes as indicated by reference numeral 206 in FIG. FIG. 3 shows an example in which a plurality of communication holes 206 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By providing a plurality of communication holes 206 evenly, the reformed gas introduced into the gap between the upper lid 200 and the distribution plate 206 serves to evenly flow toward the CO conversion catalyst layer 208. In order to make the catalyst layer temperature distribution uniform, the distribution plate 205 is provided with a plurality of communication holes 206 so that the gas hardly flows and the gas tends to decrease due to heat dissipation, and a plurality of communication holes 206 are provided to distribute the gas. Then, it is more preferable. The reformed gas that has passed through the distribution plate 205 flows into the CO shift catalyst layer 208 through the perforated plate 207, and CO in the reformed gas is changed to CO ₂ by the CO shift reaction in the CO shift catalyst, and H ₂ is also added. Generate.

  The reformed gas after the CO conversion in the CO conversion catalyst layer 208 passes through the perforated plate 209 and the distribution plate 210 and the distribution plate 210 and the lower cover 204 (the lower cover common to the fourth cylindrical body 201 and the fifth cylindrical body 203). Flows into the gap between. The distribution plate 210 has a plurality of communication holes as indicated by reference numeral 211 in FIG. FIG. 3 shows an example in which a plurality of communication holes 211 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By providing a plurality of communication holes 211 equally, the CO-modified reformed gas that has flowed into the gap between the porous plate 209 and the distribution plate 210 is directed toward the gap between the distribution plate 210 and the lower lid 204. It plays the role of evenly flowing.

  A distribution plate 213, a porous plate 215, a porous plate 217, a distribution plate 219, and an upper lid 220 are sequentially arranged between the fourth cylindrical body 201 and the fifth cylindrical body 203 with a distance from the lower lid 204. To do. All of these plate bodies are donut-shaped plate bodies because the portion corresponding to the diameter (outer diameter) of the fourth cylindrical body 201 is occupied by the fourth cylindrical body 201. Among them, the distribution plate 213 has a plurality of communication holes as indicated by reference numeral 214 in FIG.

  More specifically, the CO removal catalyst layer 216 is configured by filling a CO removal catalyst between the porous plate 215 and the porous plate 217 arranged on the distribution plate 213. The perforated plate 215 has a large number of holes, supports the CO removal catalyst, and plays a role of injecting the CO-modified reformed gas mixed with air in the CO-converting catalyst layer. The perforated plates 207 and 209 may be made of a metal mesh or the like.

The distribution plate 213 has a plurality of communication holes as indicated by reference numeral 214 in FIG. FIG. 3 shows an example in which a plurality of communication holes 214 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By providing a plurality of communication holes 214 evenly, the reformed gas introduced into the gap between the lower lid 204 and the distribution plate 213 serves to evenly flow toward the CO removal catalyst layer 216. In order to make the catalyst layer temperature distribution uniform, the distribution plate 213 is provided with a plurality of communication holes 214 so that the gas hardly flows and the temperature tends to decrease due to heat dissipation, so that a large amount of gas flows. Then, it is more preferable. The reformed gas that has passed through the distribution plate 213 flows into the CO removal catalyst layer 216 through the perforated plate 215, and CO in the reformed gas that has undergone CO conversion is converted to CO ₂ by the selective oxidation reaction of CO in the CO removal catalyst. This further reduces the CO concentration.

  The reformed gas after CO removal in the CO removal catalyst layer 216 flows into the gap between the distribution plate 218 and the upper lid 220 through the perforated plate 217 and the distribution plate 218. The distribution plate 219 has a plurality of communication holes as indicated by reference numeral 219 in FIG. FIG. 3 shows an example in which a plurality of communication holes 219 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By providing a plurality of communication holes 219 at equal intervals, the CO-removed reformed gas flowing into the gap between the porous plate 217 and the distribution plate 218 is directed toward the gap between the distribution plate 218 and the upper lid 220. Discharge evenly.

  The reformed gas in which CO is further reduced by the CO removal catalyst layer 216 is led out from the reformed gas (CO removed) take-out pipe 42 through the perforated plate 217 and the distribution plate 218, and supplied to the fuel electrode of the PEFC. .

<Regarding the preheating pipe for raw water>
A raw water preheating pipe 38 is disposed on the outer periphery of the fifth cylindrical body 203. Although a spiral preheating tube is shown in the figure, a water cooling jacket or the like can be applied as appropriate. When the fuel cell steam reformer of the present invention (2) is operated, the raw water supplied from the water supply pipe 37 is heated while flowing in the preheating pipe 38 and is heated by the heat generated in the CO removal catalyst layer 216. . Steam generated by heating is supplied to the preheating layer 10 in the cylindrical steam reformer R through a conduit 39. In the figure, the heat recovery unit is configured only around the CO removal catalyst. However, the heat recovery unit around the CO removal catalyst layer is also provided around the shift catalyst layer so that the catalyst layer temperature is appropriate. The heat recovery part may be formed in communication with the heat recovery part.

  As described above, the raw water supplied to the preheating layer 10 in the cylindrical steam reformer R is cylindrical by adopting a structure in which the raw water spiral preheating pipe 38 is arranged on the outer periphery where the CO removal catalyst layer 216 is located. The excess heat generated in the reformed gas processor B is preliminarily heated, and the heat generated in the system composed of the cylindrical steam reformer R and the cylindrical reformed gas processor B can be used effectively. .

<Embodiment of the present invention (3)>
The present invention (3) is a fuel cell steam reformer comprising a cylindrical steam reformer and a cylindrical reformed gas processor separately. And
The cylindrical steam reformer includes: (a) a plurality of first and second cylindrical bodies, each having a large diameter, arranged concentrically and spaced apart; A burner disposed from the upper end at the center in the circumferential direction of the cylindrical body, and (b) of the gaps partitioned in the circumferential direction by the first cylindrical body and the second cylindrical body, the upper gap is used as a raw fuel and a raw material. A preheating layer of a mixed flow with water, a reforming catalyst layer provided in a lower gap, and (c) the second cylinder in a gap partitioned in the circumferential direction by the second cylinder and the third cylinder Comprising a reformed gas flow channel inverted at the lower end of the body,
The cylindrical reformed gas processor is (a) larger in diameter than the outer periphery of the fourth cylinder with an interval between the outer periphery of the lower position of the fourth cylinder and the outer periphery of the fourth cylinder. A fifth cylinder is disposed, a sixth cylinder having a larger diameter than the outer periphery of the fifth cylinder is disposed at an interval on the outer periphery of the fifth cylinder, and (b) CO is disposed in the fourth cylinder. A CO conversion catalyst layer is disposed between the fifth cylinder and the sixth cylinder, and (c) the CO conversion catalyst is directed from the lower part of the CO conversion catalyst layer toward the CO removal catalyst layer. A CO-modified reformed gas flow part that has passed through the catalyst layer, an air supply pipe disposed in the flow part, and (d) a raw water preheating pipe disposed on the outer periphery of the sixth cylindrical body,
In addition, a reformed gas conduit is disposed between the reformed gas flow path of the cylindrical steam reformer and the CO shift catalyst layer.

  FIG. 4 is a diagram for explaining the present invention (3). FIG. 4 shows a structure in which the radiation cylinder 4 is provided in the cylindrical steam reformer, but the structure in which the radiation cylinder 4 is not provided is the same as that of the cylindrical steam reformer R of the present invention (1). is there.

  As shown in FIG. 4, the fuel cell steam reformer of the present invention (3) includes a cylindrical steam reformer R and a cylindrical reformed gas processor C separately. Among them, the cylindrical steam reformer R is the same as the cylindrical steam reformer R in the embodiment of the present invention (1).

<Cylindrical reformed gas processor: C>
In FIG. 4, as shown as a cylindrical reformed gas processor: C, the cylindrical reformed gas processor C is configured separately from the cylindrical steam reformer R and juxtaposed with the cylindrical steam reformer. . The cylindrical reformed gas processor C has a diameter larger than the outer circumference of the fourth cylindrical body 201 with an interval between the fourth cylindrical body 201 and the outer circumference of the lower position of the outer circumference of the fourth cylindrical body 201. The large fifth cylindrical body 202 is arranged concentrically, and the sixth cylindrical body 203 having a diameter larger than the outer circumference of the fifth cylindrical body 202 is arranged concentrically at an interval around the outer circumference of the fifth cylindrical body 202. .

  An upper lid 200 is provided at the upper end of the fourth cylindrical body 201, and the reformed gas outlet pipe 17 from the cylindrical steam reformer R is connected to the upper lid 200 and opened. In the fourth cylindrical body 201, a distribution plate 205, a porous plate 207, a porous plate 209, and a distribution plate 210 are sequentially arranged with a space from the upper lid 200. Each of these plate bodies is a disk-shaped plate body having a diameter corresponding to the inner diameter of the fourth cylindrical body 201.

  The fourth cylinder 201 is provided with a CO shift catalyst layer 208, and a CO removal catalyst layer 216 is provided between the fifth cylinder 202 and the sixth cylinder 203, and the CO shift catalyst layer 208 and the CO removal catalyst layer are provided. An air supply unit is provided at the lower part of 216. The air supply unit is configured between a lower portion of the CO shift catalyst layer 208 and the CO removal catalyst layer 216 and a lower lid 204 common to the fourth cylinder body 201 and the fifth cylinder body 203.

  As described above, in the cylindrical reformed gas processor C, the fourth cylinder 201 (having the CO shift catalyst layer 208 inside) and the fifth cylinder 202 constituting the inner periphery of the CO removal catalyst layer 216 are: Since they are arranged concentrically at intervals, the influence of the heat of the CO shift catalyst layer 208 operating at about 220 to 300 ° C. on the CO removal catalyst layer 216 (operating temperature of about 130 to 170 ° C.) should be prevented. Can do.

  More specifically, the CO shift catalyst layer 208 is configured by filling a CO shift catalyst between the porous plate 207 and the porous plate 209 in the fourth cylindrical body 201. The perforated plate 209 has a large number of holes, supports the CO conversion catalyst, and plays a role of flowing out the CO converted reformed gas in the CO conversion catalyst layer. The perforated plates 207 and 209 may be made of a metal mesh or the like.

The distribution plate 205 has a plurality of communication holes as indicated by reference numeral 206 in FIG. FIG. 4 shows an example in which a plurality of communication holes 206 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By providing a plurality of communication holes 206 in this manner, the reformed gas introduced into the gap between the upper lid 200 and the distribution plate 205 serves to evenly flow toward the CO shift catalyst layer 208. In order to make the catalyst layer temperature distribution uniform, the distribution plate 205 is provided with a plurality of communication holes 206 so that the gas hardly flows and the gas tends to decrease due to heat dissipation, and a plurality of communication holes 206 are provided to distribute the gas. Then, it is more preferable. The reformed gas that has passed through the distribution plate 205 flows into the CO shift catalyst layer 208 through the perforated plate 207, and CO in the reformed gas is changed to CO ₂ by the CO shift reaction in the CO shift catalyst, and H ₂ is also added. Generate.

  The reformed gas that has undergone CO conversion in the CO conversion catalyst layer 208 passes through the perforated plate 209 and the distribution plate 210, the distribution plate 210 and the lower lid 204 (the fourth cylindrical body 201, the fifth cylindrical body 202, and the sixth cylindrical body 203. Flows into the gap between the lower lid and the common lid. The distribution plate 210 has a plurality of communication holes as indicated by reference numeral 211 in FIG. FIG. 4 shows an example in which a plurality of communication holes 211 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By providing a plurality of communication holes 211 in this way, the CO-modified reformed gas that has flowed into the gap between the perforated plate 209 and the distribution plate 210 is directed toward the gap between the distribution plate 210 and the lower lid 204. To evenly flow in.

  A distribution plate 213, a porous plate 215, a porous plate 217, a distribution plate 218, and an upper lid 220 are sequentially arranged between the fifth cylindrical body 202 and the sixth cylindrical body 203 at a distance from the lower lid 204. . Since these plate bodies are horizontally provided between the fifth cylindrical body 202 and the sixth cylindrical body 203, a portion corresponding to the diameter (inner diameter) of the fifth cylindrical body 202 is occupied by the fourth cylindrical body 202. It is a donut-shaped plate.

  The CO removal catalyst layer 216 is configured by filling a CO removal catalyst between the porous plate 215 and the porous plate 217 arranged on the distribution plate 213. The perforated plate 215 has a large number of holes, supports the CO removal catalyst, and plays a role of flowing a mixed flow in which air is mixed into the CO-modified reformed gas from the CO-modified catalyst layer. The perforated plates 207 and 209 may be made of a metal mesh or the like.

The distribution plate 213 has a plurality of communication holes as indicated by reference numeral 214 in FIG. FIG. 4 shows an example in which a plurality of communication holes 214 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By providing a plurality of communication holes 214 in such a manner, the role of uniformly flowing CO reformed reformed gas introduced into the gap between lower lid 204 and distribution plate 213 toward CO removal catalyst layer 216. do. In order to make the catalyst layer temperature distribution uniform, the distribution plate 213 is provided with a plurality of communication holes 214 so that the gas hardly flows and the temperature tends to decrease due to heat dissipation, so that a large amount of gas flows. Then, it is more preferable. The reformed gas that has passed through the distribution plate 213 flows into the CO removal catalyst layer 216 through the perforated plate 215, and CO in the reformed gas that has undergone CO conversion is converted to CO ₂ by the selective oxidation reaction of CO in the CO removal catalyst. This further reduces the CO concentration.

  The reformed gas after CO removal in the CO removal catalyst layer 216 flows into the gap between the distribution plate 218 and the upper lid 220 through the perforated plate 217 and the distribution plate 218. The distribution plate 218 has a plurality of communication holes as indicated by reference numeral 219 in FIG. FIG. 4 shows an example in which a plurality of communication holes 219 are provided at equal intervals from the center of the disk-shaped plate body and at equal intervals in the circumferential direction. By providing a plurality of communication holes 219 in this manner, the CO-removed reformed gas that has flowed into the gap between the porous plate 217 and the distribution plate 218 is directed toward the gap between the distribution plate 218 and the upper lid 220. Discharge evenly.

  As such, the CO removal catalyst layer 216 further reduces the CO in the CO-modified reformed gas, and is led out from the reformed gas (CO-removed) take-out pipe 42 through the perforated plate 217 and the distribution plate 218, and the PEFC Supplied to the fuel electrode.

<Regarding the preheating pipe for raw water>
A raw water preheating pipe 38 is disposed on the outer periphery of the sixth cylindrical body 203. Although a spiral preheating tube is shown in the figure, a water cooling jacket or the like can be applied as appropriate. When the fuel cell steam reformer of the present invention (4) is operated, the raw water supplied from the water supply pipe 37 is heated while flowing in the preheating pipe 38 and is heated by the heat generated in the CO removal catalyst layer 216. . Steam generated by heating is supplied to the preheating layer 10 in the cylindrical steam reformer R through a conduit 39. In the figure, the heat recovery unit is configured only around the CO removal catalyst. However, the heat recovery unit around the CO removal catalyst layer is also provided around the shift catalyst layer so that the catalyst layer temperature is appropriate. The heat recovery part may be formed in communication with the heat recovery part.

  Thus, the raw material supplied to the preheating layer 10 in the cylindrical steam reformer R by adopting a structure in which the raw water preheating pipe 38 is arranged on the outer periphery of the sixth cylindrical body 203 where the CO removal catalyst layer 216 is located. Water is preheated using excess heat generated in the cylindrical reformed gas processor C, and the heat generated in the system composed of the cylindrical steam reformer R and the cylindrical reformed gas processor C is effectively used. can do.

<About the electric heater>
Also in the cylindrical reformed gas processor A and the cylindrical reformed gas processor B, an electric heater is arranged on the outer periphery, and when the steam reformer is started, it is turned on together with the CO conversion catalyst layer. The CO removal catalyst layer can also be heated, but even if the electric heater is covered with a heat insulating material, a part of the heat generation is dissipated and cannot be used effectively. On the other hand, in the cylindrical reformed gas processor C, the fourth cylindrical body 201 and the fifth cylindrical body 202 are arranged at an interval, but between the fourth cylindrical body 201 and the fifth cylindrical body 202. An electric heater 221 may be disposed on the front panel. By doing in this way, heat_generation | fever of the electric heater 221 can be utilized effectively, reducing heat dissipation loss as much as possible.

<Mode in which a high temperature CO conversion catalyst and a low temperature CO conversion catalyst are arranged in the CO conversion catalyst layer>
In the steam reforming apparatus of the present invention, the CO conversion catalyst layer can be formed by laminating a high temperature CO conversion catalyst layer and a low temperature CO conversion catalyst layer, or each independently. Speaking of the stacked structure in FIG. 1 [present invention (1)], the upper part of the CO conversion catalyst layer 23 is a high temperature CO conversion catalyst layer, and the lower part is a low temperature CO conversion catalyst. The high-temperature CO conversion catalyst can be used continuously at least at 350 ° C. or higher, and examples thereof include Pt-based, Fe / Cr-based, and Fe / Al-based catalysts.

  For the low temperature CO conversion catalyst, a normal CO conversion catalyst such as a Cu / Zn system is used. The amount of the high-temperature CO conversion catalyst used is, for example, about 1/3 of the total CO conversion catalyst. For example, the temperature of the reformed gas introduced from the cylindrical steam reformer through the reformed gas outlet pipe 17 and the reforming It can be set as appropriate in consideration of the heat balance in the reformed gas processor itself. The same applies to the steam reforming apparatuses of the present inventions (2) to (3).

  Hereinafter, the present invention will be further described based on experimental examples, but the present invention is not limited to the experimental examples.

<Experimental example 1>
Experimental Example 1 is a fuel cell steam reformer comprising a cylindrical steam reformer and a cylindrical reformed gas processor according to the present invention (2) shown in FIG. Such an experiment was conducted. The steam reformer having the structure shown in FIG. 3 was manufactured and operated, the temperature at each part in each steam reformer was measured, and the state of the temperature distribution at each part was observed.

  A Ru-based catalyst having an operating temperature of about 400 to 680 ° C. is used as the reforming catalyst of the reforming catalyst layer, and a copper-zinc based catalyst having an operating temperature of about 220 to 330 ° C. is used as the CO conversion catalyst of the CO conversion catalyst layer. A Ru catalyst having an operating temperature of about 130 to 170 ° C. was used as the CO removal catalyst of the CO removal catalyst layer.

  Temperature measurement is performed with a thermocouple, and the thermocouple installation position, which is a temperature measurement location, is shown in FIG. Regarding the CO shift catalyst layer, the three positions of the CO shift catalyst layer inlet portion, the CO shift catalyst layer intermediate portion, and the CO shift catalyst layer outlet portion, respectively, in the flow direction of the reformed gas, Measurements were made at a total of 6 locations.

  Other experimental conditions and experimental results are shown in Table 1. In Table 1, the central part of the outlet of the reforming catalyst layer is the position of the central part as viewed in the radial direction, and the CO shift catalyst layer is cylindrical, so only the central part and the outer side, so there is no inner side.

  As shown in Table 1, the CO conversion catalyst layer inlet temperature is 282.4 ° C. at the center and 279.4 ° C. outside, and the intermediate temperature of the CO conversion catalyst layer is 303.5 ° C. at the center. The temperature at the outside is 292.9 ° C., and the temperature at the CO conversion catalyst layer outlet is 258.9 ° C. at the center and 247.2 ° C. at the outside. Thus, in any part, it is in the range of 220-330 degreeC suitable temperature of a CO conversion catalyst, and the width | variety of the temperature difference is small about the temperature of each part, and it can be said that it is substantially equal.

  The CO removal catalyst layer temperature is 187.2 ° C. at the CO removal catalyst layer inlet and 160.3 ° C. at the CO removal catalyst layer outlet. Although the CO removal catalyst layer inlet temperature is slightly higher than the appropriate temperature of 130 to 170 ° C. for the CO removal catalyst, it can be easily solved by increasing the area in contact with the raw water preheating pipe at the CO removal catalyst layer inlet. . The CO removal catalyst layer outlet temperature is within the appropriate temperature range of the CO removal catalyst.

<Experimental example 2>
Experimental Example 2 shows a fuel cell steam reformer comprising a cylindrical steam reformer and a cylindrical reformed gas processor according to the present invention (3) shown in FIG. Such an experiment was conducted. The steam reformer having the structure shown in FIG. 4 was manufactured and operated, and the temperature at each part in each steam reformer was measured, and the state of the temperature distribution at each part was observed. The reforming catalyst, the CO shift catalyst, and the CO removal catalyst are the same as in Experimental Example 1.
In Experimental Example 2, the electric heater is operated only for the purpose of preventing dew condensation in the catalyst layer at the start-up, and is not operated in a steady state.

  Temperature measurement is performed with a thermocouple, and in FIG. 4, the thermocouple installation position, which is a temperature measurement location, is shown. Regarding the CO shift catalyst layer, the three positions of the CO shift catalyst layer inlet portion, the CO shift catalyst layer intermediate portion, and the CO shift catalyst layer outlet portion, respectively, in the flow direction of the reformed gas, Measurements were made at a total of 6 locations.

  Other experimental conditions and experimental results are shown in Table 2. In Table 2, the central part of the outlet of the reforming catalyst layer is the position of the central part as viewed in the radial direction, and the CO conversion catalyst layer is cylindrical, so only the central part and the outer side, so there is no inner side. Further, the CO removal catalyst layer in the structure of FIG. 4 has a cylindrical shape, the inside is a position near the CO conversion catalyst layer, and the outside is a position near the raw water preheating pipe 38.

  As shown in Table 2, the CO conversion catalyst layer inlet temperature was 286.9 ° C. at the center and 293.8 ° C. outside, and the intermediate temperature of the CO conversion catalyst layer was 280.6 ° C. at the center. The temperature at the outside is 269.2 ° C., and the temperature at the CO conversion catalyst layer outlet is 253.6 ° C. at the center and 241.8 ° C. at the outside. Thus, in any part, it is in the range of 220-330 degreeC suitable temperature of a CO conversion catalyst, and the width | variety of the temperature difference is small about the temperature of each part, and it can be said that it is substantially equal.

  The CO removal catalyst layer temperature is 152.8 ° C. inside the CO removal catalyst layer inlet and 126.4 ° C. outside, 119.4 ° C. inside the CO removal catalyst layer outlet, and 108.3 outside. ° C. Except for the temperature inside the CO removal catalyst layer inlet, it is slightly lower than the appropriate temperature of 130 to 170 ° C for the CO removal catalyst, but at the CO removal catalyst layer inlet, the area in contact with the raw material pipe preheating pipe is reduced to remove CO. This can be solved easily by increasing the catalyst layer inlet temperature. It is also possible to compensate by operating an electric heater.

The figure explaining the aspect of this invention (1) The figure explaining the aspect of this invention (1) The figure explaining the aspect of this invention (2) The figure explaining the aspect of this invention (3) Diagram explaining the system from raw fuel processing to PEFC The figure which shows the integrated multi-cylinder steam reformer (prior art) of a CO shift catalyst layer and a CO removal catalyst layer

Explanation of symbols

1-3, 101-103 1st cylinder body-3rd cylinder body 4, 104 Radiation cylinder 5 Bottom plate of 1st cylinder body 6 Burner 7 Upper lid and burner mounting base 8, 141 Combustion exhaust gas discharge pipe 10 Raw fuel and water vapor Preheating layer 11, 115 Spiral rod 13, 116 Reforming catalyst layer 15 Bottom plate 16 of third cylindrical body 16, 120 Reformed gas flow path 37, 142 Raw water introduction pipe 38 Raw water spiral preheating pipe 39 Steam supply Pipes 40 and 143 Raw fuel introduction pipes 41 and 144 Air supply pipes 45 and 145 Reformed gas outlet pipes 201 to 203 Fourth cylinder to sixth cylinders 23 and 208 CO conversion catalyst layer 32 and 216 CO removal catalyst layer 221 Electricity heater

Claims (3)

A steam reformer for a fuel cell comprising a cylindrical steam reformer and a cylindrical reformed gas processor separately,
The cylindrical steam reformer is
(A) a plurality of first and second cylindrical bodies, each of which is arranged concentrically and spaced apart from each other, and has an upper end at a central portion in the circumferential direction of the first cylindrical body; With a burner arranged from
(B) Of the gaps defined in the circumferential direction by the first cylinder and the second cylinder, the upper gap is used as a preheating layer for the mixed flow of raw fuel and raw water, and the lower gap is modified. With a catalyst layer,
(C) comprising a reformed gas flow channel that is inverted at the lower end of the second cylindrical body in a gap partitioned in the circumferential direction by the second cylindrical body and the third cylindrical body;
The cylindrical reformed gas processor is
(A) A fifth cylinder having a diameter larger than the outer circumference of the fourth cylinder and a fourth cylinder having a diameter larger than the outer circumference of the fourth cylinder is spaced apart from the outer circumference of the lower position of the fourth cylinder. A sixth cylinder having a larger diameter than the outer periphery of the fifth cylinder is arranged at an interval on the outer periphery of the five cylinder,
(B) A CO shift catalyst layer is disposed in the fourth cylinder, and a CO removal catalyst layer is provided between the fifth cylinder and the sixth cylinder,
(C) From the lower part of the CO conversion catalyst layer toward the CO removal catalyst layer, a CO-modified reformed gas circulation part that has passed through the CO conversion catalyst layer is provided, and an air supply pipe is disposed in the circulation part, (D) A raw water preheating pipe is disposed on the outer periphery of the sixth cylindrical body,
A steam reformer for a fuel cell, comprising a reformed gas conduit disposed between a reformed gas flow path of the cylindrical steam reformer and the CO shift catalyst layer. 2. The steam reformer for a fuel cell according to claim 1 , wherein an electric heater is disposed on an outer periphery of the fourth cylindrical body between the fourth cylindrical body and the fifth cylindrical body. Steam reformer for fuel cells. The cylindrical steam reformer for a fuel cell according to claim 1 or 2 , further comprising a radiation cylinder inside the first cylinder in the steam reformer. .

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