JP5993721B2 - Hydrogen production apparatus and fuel cell system - Google Patents

Description

  Embodiments described herein relate generally to a hydrogen production apparatus and a fuel cell system.

  A polymer electrolyte fuel cell system using a commercial gas fuel such as city gas or LPG as a raw fuel has a hydrogen production apparatus for producing a fuel gas containing hydrogen from the raw fuel. Of the various methods for producing fuel gas from raw fuel, the following steam reforming reaction is often used.

C _n H _m + nH ₂ O → nCO + (m / 2 + n) H ₂ (steam reforming reaction)
The reforming reaction is generally an endothermic reaction, and heat is applied from the outside to advance the reaction. As a heat source, in many cases, hydrogen gas exhausted without reacting at the anode of the battery cell stack or heat generated by burning raw fuel is used. In order to suppress the reaction temperature, for example, a reforming reaction may be performed using a catalyst containing nickel (Ni) or the like.

  Carbon monoxide (CO) generated in the reforming reaction lowers the voltage of the battery cell in a polymer electrolyte fuel cell. For this reason, CO is generally removed from the fuel gas using the following shift reaction.

CO + H ₂ O → CO ₂ + H ₂ (shift reaction)
The shift reaction is an exothermic reaction, and heat is removed from the fuel gas in order to maintain an optimum temperature range for the reaction. Further, in order to keep the temperature low, a catalyst containing copper (Cu), zinc (Zn) or the like is often used.

  In the shift reaction, the CO concentration of the fuel gas can be reduced only to about 100 ppm due to the equilibrium limit of the reaction. For this reason, the following oxidation reaction is used after the shift reaction to further reduce the CO concentration of the fuel gas.

CO + 1 / 2O ₂ → CO ₂ (CO oxidation reaction)
The oxidation reaction is performed by mixing air into the fuel gas. Due to the oxidation reaction, the CO concentration of the fuel gas is reduced to 10 ppm or less. However, hydrogen (H ₂ ) in the fuel gas may be oxidized as follows.

H ₂ + 1 / 2O ₂ → H ₂ O (H ₂ oxidation reaction)
A so-called selective oxidation reaction catalyst is used to minimize oxidation of H ₂ and oxidize all CO.

  On the other hand, an odorant containing a sulfur content is added to the commercial gas fuel so that gas leakage can be understood. When the odorant adheres to the reforming catalyst, the reforming reaction is inhibited. For this reason, the raw fuel is generally desulfurized before entering the reforming catalyst layer. For desulfurization, for example, a desulfurizing agent that adsorbs and removes sulfur is used.

JP 2010-58995 A

  In order to remove CO from the fuel gas by the oxidation reaction, means for introducing air is required, and the structure of the hydrogen production apparatus becomes complicated. However, a large amount of catalyst is required to reduce the CO concentration of the fuel gas to a value that allows the battery cell stack to operate (for example, 500 ppm) only by the shift reaction. Therefore, there is a need for a method of further removing CO without using an oxidation reaction from a fuel gas having a CO concentration reduced to, for example, about 5000 to 1000 ppm in the shift catalyst layer.

  The problem to be solved by the present invention is to provide a hydrogen production apparatus and a fuel cell system having a simple configuration.

A hydrogen production apparatus according to one embodiment includes first to sixth cylindrical members, a burner, a CO shift catalyst layer, and a CO removal catalyst layer. One end of the first cylindrical member is opened. The burner is disposed at the other end of the first cylindrical member and heats the inside of the first cylindrical member. The second cylindrical member is positioned coaxially with the first cylindrical member and accommodates at least a part of the first cylindrical member, and the first cylindrical member is interposed between the first cylindrical member and the first cylindrical member. A gap is formed through which the exhaust of the burner coming out from one end of the cylindrical member passes. The third cylindrical member is positioned coaxially with the first cylindrical member and covers a part of the second cylindrical member in the axial direction, and hydrocarbons are provided between the second cylindrical member and the second cylindrical member. An evaporation channel through which the raw fuel gas and water are passed is formed. The fourth cylindrical member is positioned coaxially with the first cylindrical member, covers a part of the second cylindrical member in the axial direction, and the evaporative flow between the second cylindrical member and the second cylindrical member. The raw fuel gas that has passed through the passage passes therethrough to form a first reaction flow path in which a reforming catalyst layer that forms a fuel gas containing hydrogen from the raw fuel gas is disposed. The fifth cylindrical member is positioned coaxially with the first cylindrical member and accommodates at least a part of the third and fourth cylindrical members, and the fifth cylindrical member is interposed between the fourth cylindrical member and the fourth cylindrical member. A regeneration channel through which the fuel gas that has passed through the first reaction channel passes is formed, and a second reaction channel connected to the regeneration channel is formed between the third cylindrical member and the second reaction channel. . The CO shift catalyst layer is disposed in the second reaction flow path, and the fuel gas that has passed through the regeneration flow path passes through and removes carbon monoxide from the fuel gas. The CO removal catalyst layer is disposed in the second reaction channel, and the raw fuel gas that has passed through the shift catalyst layer passes through, and carbon monoxide is removed from the fuel gas by a methanation reaction. The sixth cylindrical member is positioned coaxially with the first cylindrical member, covers a part of the fifth cylindrical member in the axial direction, and the evaporative flow between the fifth cylindrical member and the fifth cylindrical member. A desulfurization flow path is formed in which a hydrodesulfurization catalyst layer for desulfurizing the raw fuel gas toward the evaporation flow path is disposed. The hydrodesulfurization catalyst layer extends between the regeneration channel and the CO shift catalyst layer in the axial direction of the first cylindrical member.

1 is a cross-sectional view schematically showing a fuel cell system according to one embodiment. Sectional drawing which shows the hydrogen production apparatus of one embodiment. Sectional drawing which shows the burner of one embodiment. The perspective view which shows the 2nd cylindrical member of one embodiment.

  Hereinafter, an embodiment will be described with reference to FIGS. 1 to 4. In addition, one or more examples of other expressions may be given for each element that can be expressed in multiple ways, but this does not deny that different elements are expressed differently. Nor is it intended to limit other expressions not illustrated.

  FIG. 1 is a cross-sectional view schematically showing a fuel cell system 1 according to one embodiment. As shown in FIG. 1, the fuel cell system 1 includes a hydrogen production apparatus 10, a raw fuel supply unit 11, a cooler 12, a cell stack assembly (CSA) 13, a drain 14, an air supply unit 15, And a water supply unit 16. The CSA 13 is an example of a fuel battery cell.

  The CSA 13 has a plurality of polymer electrolyte fuel cells stacked through separators. CSA generates electricity using a fuel gas containing hydrogen and an oxidant gas containing oxygen. The hydrogen production apparatus 10 produces fuel gas supplied to the CSA 13.

  FIG. 2 is a cross-sectional view showing the hydrogen production apparatus 10. As shown in FIG. 2, the hydrogen production apparatus 10 includes a first cylindrical member (combustion tube) 21, a second cylindrical member (heat transfer tube) 22, a third cylindrical member (evaporation tube) 23, 4 cylindrical member 24, fifth cylindrical member 25, sixth cylindrical member 26, seventh cylindrical member 27, burner 31, reforming catalyst layer 32, shift catalyst layer 33, and methanation. A catalyst layer 34 and a hydrodesulfurization catalyst layer 35 are provided. The shift catalyst layer 33 is an example of a CO shift catalyst layer. The methanation catalyst layer 34 is an example of a CO removal catalyst layer.

  The 1st thru | or 7th cylindrical members 21-27 are formed in the cylindrical shape from which a diameter differs, for example with a metal. The first to seventh cylindrical members 21 to 27 are arranged coaxially. The second to seventh cylindrical members 22 to 27 may be displaced from the central axis of the first cylindrical member 21.

  As for the 1st cylindrical member 21, one edge part 21a is open | released and the other edge part 21b is obstruct | occluded. A burner 31 is disposed at the other end 21b. 1 and 2, the burner 31 is schematically shown.

  FIG. 3 is a sectional view showing the burner 31. As shown in FIG. 3, the burner 31 has an ignition rod 41, an insulating material 42, a fuel nozzle 43, and an air nozzle 44. The insulating material 42 surrounds the ignition rod 41 in the radial direction. The fuel nozzle 43 is disposed outside the insulating material 42 in the radial direction. The air nozzle 44 is disposed outside the fuel nozzle 43 in the radial direction.

  As shown in FIG. 1, the burner 31 is connected to the CSA 13 and the air supply unit 15. The air supply unit 15 is, for example, a compressor or a blower. As shown in FIG. 3, the fuel nozzle 43 injects the fuel gas (anode off gas) exhausted without reacting with the fuel cell of the CSA 13 to the vicinity of the tip of the ignition rod 41 (combustion space). The air nozzle 44 ejects the air supplied by the air supply unit 15 into the combustion space.

  As shown in FIG. 1, the burner 31 burns anode off gas inside the first cylindrical member 21. The anode off gas and air cause diffusion combustion to become a combustion gas having a temperature of about 1000 to 1300 ° C. Thereby, the inside of the first cylindrical member 21 is heated. The combustion gas of the burner 31 passes through the inside of the first cylindrical member 21 as shown by the arrow in FIG.

  The second cylindrical member 22 has a larger diameter than the first cylindrical member 21 and accommodates the first cylindrical member 21. Both ends of the second cylindrical member 22 are closed. One end 21 a of the first cylindrical member 21 is opened in the space inside the second cylindrical member 22.

  A gap S1 is formed between the first cylindrical member 21 and the second cylindrical member 22 in the radial direction. The combustion gas of the burner 31 that has passed through the first cylindrical member 21 exits one end 21a of the first cylindrical member 21 and passes through the gap S1. Thus, the 2nd cylindrical member 22 is heated because high temperature combustion gas passes gap | interval S1.

  An exhaust pipe 51 is attached near the upper end of the second cylindrical member 22. The exhaust pipe 51 is connected to the gap S1. The combustion gas that has passed through the gap S <b> 1 is discharged out of the hydrogen production apparatus 10 through the exhaust pipe 51. Note that the temperature of the combustion gas is, for example, 60 to 100 ° C. when passing through the exhaust pipe 51.

  The third cylindrical member 23 has a larger diameter than the second cylindrical member 22 and covers a part of the second cylindrical member 22 in the axial direction. In other words, the third cylindrical member 23 is formed in a cylindrical shape shorter than the second cylindrical member 22, and is covered outside the second cylindrical member 22.

  An evaporation channel S2 is formed between the second cylindrical member 22 and the third cylindrical member 23 in the radial direction. A raw fuel gas containing hydrocarbons and reformed water are supplied from one end of the evaporation channel S2. The raw fuel gas is a commercial gas fuel such as city gas or LPG. The reforming water is liquid water supplied from the water supply unit 16.

  FIG. 4 is a perspective view showing the second cylindrical member 22. As shown in FIG. 4, a spiral bar 53 is attached to the outer periphery of the second cylindrical member 22. As shown in FIG. 1, the bar 53 is disposed in the evaporation channel S2. For this reason, the raw fuel gas and the reformed water pass along the bar 53 while turning in the evaporation flow path S2.

  The fourth cylindrical member 24 has a larger diameter than the third cylindrical member 23 and covers a part of the second cylindrical member 22 in the axial direction. In other words, the fourth cylindrical member 24 is formed in a cylindrical shape shorter than the second cylindrical member 22, and is covered outside the second cylindrical member 22.

  In the axial direction, the fourth cylindrical member 24 is disposed adjacent to the third cylindrical member 23. The lower end 24a of the fourth cylindrical member 24 and the lower end 24a of the second cylindrical member 22 are located on the same plane. The lower ends 22a and 24a of the second and fourth cylindrical members 22 and 24 may be shifted. The lower end 24a of the fourth cylindrical member 24 is open.

  A first reaction channel S3 is formed between the second cylindrical member 22 and the fourth cylindrical member 24 in the radial direction. The cross-sectional area of the first reaction channel S3 is larger than the cross-sectional area of the evaporation channel S2. The first reaction channel S3 is connected to the evaporation channel S2.

  The reforming catalyst layer 32 is disposed in the first reaction channel S3. The lower end of the reforming catalyst layer 32 is positioned approximately at the same height as the lower end 24 a of the fourth cylindrical member 24. As shown by the arrow in FIG. 2, the raw fuel gas and the reformed water that have passed through the evaporation channel S <b> 2 pass through the reforming catalyst layer 32.

  In the reforming catalyst layer 32, a steam reforming reaction occurs in the raw fuel gas and the reformed water. Thereby, carbon monoxide (CO) and fuel gas (hydrogen rich gas) are made from raw fuel gas.

  The fifth cylindrical member 25 has a larger diameter than the third and fourth cylindrical members 23 and 24 and accommodates the third and fourth cylindrical members 23 and 24. Both ends of the fifth cylindrical member 25 are closed. A lower end 24 a of the fourth cylindrical member 24 is opened in the space inside the fifth cylindrical member 25.

  A regeneration flow path S4 is formed between the fourth cylindrical member 24 and the fifth cylindrical member 25 in the radial direction. The fuel gas, CO, and the remaining reformed water that have passed through the first reaction channel S3 exit the lower end 24a of the fourth cylindrical member 24 and pass through the regeneration channel S4.

  A second reaction channel S5 is formed between the third cylindrical member 23 and the fifth cylindrical member 25 in the radial direction. The cross-sectional area of the second reaction channel S5 is larger than the cross-sectional area of the regeneration channel S4. The second reaction channel S5 is connected to the regeneration channel S4.

The shift catalyst layer 33 is disposed in the second reaction channel S5. The fuel gas, CO, and reformed water that have passed through the regeneration channel S4 pass through the shift catalyst layer 33. In the shift catalyst layer 33, a shift reaction occurs in CO and reformed water. Thus, the CO and the reforming water, carbon dioxide (CO ₂₎ and _{H 2} are made. In other words, the shift catalyst layer 33 removes carbon monoxide from the fuel gas by a shift reaction.

  The methanation catalyst layer 34 is disposed in the second reaction channel S5. The methanation catalyst layer 34 is adjacent to the shift catalyst layer 33 via a gap in the axial direction. The methanation catalyst layer 34 is farther from the regeneration channel S4 than the shift catalyst layer 33. The fuel gas that has passed through the shift catalyst layer 33 and the remaining CO pass through the methanation catalyst layer 34.

In the methanation catalyst layer 34, the following methanation reaction occurs between CO and H ₂ contained in the fuel gas. The methanation reaction is an inverse reaction of the steam reforming reaction and is an exothermic reaction.

CO + 3H ₂ → CH ₄ + H ₂ O (methanation reaction)
The methanation reaction produces methane (CH ₄ ) and water from CO and H ₂ . In other words, the methanation catalyst layer 34 removes carbon monoxide from the fuel gas by a methanation reaction.

  A discharge port 55 is provided near the upper end portion of the fifth cylindrical member 25. The discharge port 55 is open to the second reaction channel S5. The discharge port 55 is farther from the regeneration flow path S4 than the methanation catalyst layer 34. Fuel gas that has passed through the methanation catalyst layer 34, reformed water, water generated by the methanation reaction, and CO are discharged from the outlet 55.

  The sixth cylindrical member 26 has a larger diameter than the fifth cylindrical member 25 and covers a part of the fifth cylindrical member 25 in the axial direction. In other words, the sixth cylindrical member 26 is formed in a cylindrical shape shorter than the fifth cylindrical member 25, and is covered outside the fifth cylindrical member 25. Both ends of the sixth cylindrical member 26 are closed.

  A desulfurization flow path S6 is formed between the fifth cylindrical member 25 and the sixth cylindrical member 26 in the radial direction. The hydrodesulfurization catalyst layer 35 is disposed in the desulfurization flow path S6. The hydrodesulfurization catalyst layer 35 is formed of, for example, one type of catalyst. The hydrodesulfurization catalyst layer 35 is disposed between the regeneration channel S4 and the shift catalyst layer 33 in the axial direction of the first cylindrical member 21. In other words, in the radial direction, the hydrodesulfurization catalyst layer 35 is located outside the upper end of the regeneration channel S4 and the lower end of the shift catalyst layer 33.

  The raw fuel gas before being supplied to the evaporation flow path S2 passes through the hydrodesulfurization catalyst layer 35 disposed in the desulfurization flow path S6. In the hydrodesulfurization catalyst layer 35, the odorant containing sulfur content mixed with the raw fuel gas is removed. In other words, the hydrodesulfurization catalyst layer 35 desulfurizes the raw fuel gas. More specifically, the hydrodesulfurization catalyst layer 35 changes the component of the odorant into hydrogen sulfide and adsorbs and removes the hydrogen sulfide.

  A raw fuel discharge port 57 is provided at the lower end of the sixth cylindrical member 26. The raw fuel discharge port 57 opens to the desulfurization flow path S6 and is connected to one end of the evaporation flow path S2 through, for example, a pipe. In other words, the desulfurization flow path S6 is connected to the evaporation flow path S2. For this reason, the raw fuel gas from which the odorant has been removed travels through the raw fuel discharge port 57 toward the evaporation flow path S2.

  The seventh cylindrical member 27 has a larger diameter than the fifth cylindrical member 25 and covers a part of the fifth cylindrical member 25 in the axial direction. In other words, the seventh cylindrical member 27 is formed in a cylindrical shape shorter than the fifth cylindrical member 25, and is covered outside the fifth cylindrical member 25. In the axial direction, the seventh cylindrical member 27 is adjacent to the sixth cylindrical member 26. The diameter of the seventh cylindrical member 27 is smaller than the diameter of the sixth cylindrical member 26.

  In the radial direction, a preheating flow path S <b> 7 is formed between the fifth cylindrical member 25 and the seventh cylindrical member 27. The cross-sectional area of the preheating channel S7 is smaller than the cross-sectional area of the desulfurization channel S6. The preheating channel S7 is connected to the desulfurization channel S6.

  A raw fuel supply port 59 is provided near the upper end of the seventh cylindrical member 27. As shown in FIG. 1, the raw fuel supply port 59 opens into the preheating flow path S7 and is connected to the raw fuel supply unit 11 via, for example, a pipe. The raw fuel supply unit 11 supplies raw fuel gas mixed with an odorant. The raw fuel gas supplied from the raw fuel supply unit 11 passes through the preheating channel S7 and travels toward the desulfurization channel S6.

  The preheating channel S <b> 7 is disposed so as to cover a part of the shift catalyst layer 33 and the methanation catalyst layer 34 in the axial direction of the first cylindrical member 21. In other words, the preheating channel S <b> 7 is a channel that passes outside the shift catalyst layer 33 and the methanation catalyst layer 34.

  As shown in FIG. 1, the discharge port 55 opened to the second reaction channel S5 is connected to the cooler 12 through a pipe, for example. The cooler 12 cools the fuel gas discharged from the discharge port 55 and water. Thereby, the water which was gaseous is condensed.

  The cooler 12 is connected to the CSA 13, the drain 14, and the raw fuel supply port 59. The water condensed in the cooler 12 is discharged from the drain 14. The fuel gas cooled by the cooler 12 is supplied to the CSA 13. Part of the fuel gas (for example, 1 to 2%) is mixed with the raw fuel supplied from the raw fuel supply unit 11 and supplied to the raw fuel supply port 59.

  The CSA 13 generates power using the supplied fuel gas and supplies the remaining fuel gas (anode off gas) to the burner 31. The raw fuel gas may be supplied to the burner 31 in addition to the remaining fuel gas.

  An example of a method in which the hydrogen production apparatus 10 produces fuel gas will be described in detail below. First, the raw fuel gas in the raw fuel supply unit 11 is mixed with a part of the fuel gas supplied from the cooler 12 and supplied to the preheating channel S7. As shown in FIG. 2, at the raw fuel supply port 59 to which the raw fuel gas is supplied, the temperature of the raw fuel gas is, for example, room temperature (25 ° C.).

  The raw fuel gas passes through the preheating channel S7 and is supplied to the desulfurization channel S6 while being heated by the fifth cylindrical member 25. The temperature of the raw fuel gas that has passed through the preheating flow path S7 is, for example, 250 ° C.

  The raw fuel gas is desulfurized by passing through the hydrodesulfurization catalyst layer 35. The desulfurized raw fuel gas passes through the desulfurization flow path S6 and is supplied to the evaporation flow path S2. The hydrodesulfurization catalyst layer 35 is heated by the fifth cylindrical member 25. The temperature of the hydrodesulfurization catalyst layer 35 is, for example, 250 ° C. suitable for hydrodesulfurization reaction. Since the raw fuel gas supplied to the evaporation flow path S2 is cooled when passing through the pipe, it becomes, for example, room temperature (25 ° C.).

  The raw fuel gas is mixed with the reforming water and passes through the evaporation flow path S2. In the evaporation flow path S <b> 2, the raw fuel gas and the reformed water are heated by the second cylindrical member 22 and the third cylindrical member 23. The temperature of the raw fuel gas that has passed through the evaporation flow path S2 is, for example, 250 to 300 ° C. The reforming water evaporates in the evaporation channel S2.

The raw fuel gas passes through the first reaction channel S3. When the raw fuel gas passes through the reforming catalyst layer 32, it becomes a fuel gas (mixed gas of H ₂ , CO, CO ₂ , H ₂ O, and CH ₄ ) by the reforming reaction. Since the reforming reaction is an endothermic reaction, the raw fuel gas is heated by the second cylindrical member 22 and absorbs heat from the fourth cylindrical member 24. The temperature of the fuel gas that has passed through the first reaction channel S3 is, for example, 630 to 680 ° C.

  The fuel gas passes through the regeneration channel S4. In the regeneration channel S4, the fuel gas absorbs heat from the raw fuel gas passing through the first reaction channel S3 via the fourth cylindrical member 24. Thus, the heat of the fuel gas passing through the regeneration channel S4 is used for the reforming reaction. Further, the fuel gas passing through the regeneration channel S4 is cooled by the raw fuel gas and the outside air in the desulfurization channel S6 via the fifth cylindrical member 25. The temperature of the fuel gas in the regeneration channel S4 is, for example, 350 ° C., and the temperature of the fuel gas that has passed through the regeneration channel S4 is, for example, 250 ° C.

  The fuel gas passes through the shift catalyst layer 33 of the second reaction channel S5. From the fuel gas, CO is removed by a shift reaction in the shift catalyst layer 33. As a result, the CO concentration of the fuel gas is reduced to, for example, 5000 ppm or less.

  The shift reaction is an exothermic reaction, but its effect is small. The heat of the fuel gas is cooled by the raw fuel gas passing through the desulfurization passage S6 and the preheating passage S7 via the fifth cylindrical member 25. Further, the heat of the fuel gas is cooled by the raw fuel gas and the reforming water that pass through the evaporation flow path S <b> 2 via the third cylindrical member 23. The temperature of the fuel gas that has passed through the shift catalyst layer 33 is, for example, 150 to 200 ° C.

  The fuel gas passes through the methanation catalyst layer 34. From the fuel gas, CO is removed in the methanation catalyst layer 34 by a methanation reaction. As a result, the CO concentration of the fuel gas is reduced to, for example, 500 ppm or less.

  Although the methanation reaction is exothermic, its effect is small. The heat of the fuel gas is cooled by the raw fuel gas passing through the preheating channel S7 via the fifth cylindrical member 25. Further, the heat of the fuel gas is cooled by the raw fuel gas and the reforming water that pass through the evaporation flow path S <b> 2 via the third cylindrical member 23. The temperature of the fuel gas that has passed through the methanation catalyst layer 34 is, for example, 100 to 150 ° C.

As described above, a fuel gas having a CO concentration of 500 ppm or less is produced. In the fuel gas, for example, the H ₂ concentration is 65 to 80% dry, the CH ₄ is 1 to 3% dry, and the CO ₂ is the remainder. The fuel gas is cooled by the cooler 12 and supplied to the CSA 13. The CSA 13 generates electricity using the fuel gas produced by the hydrogen production apparatus 10. A part of the fuel gas is supplied to the preheating channel S7 together with the raw fuel gas. Hydrogen contained in the fuel gas is used in the hydrodesulfurization catalyst layer 35.

  According to the fuel cell system 1 having the configuration, after the CO of the fuel gas is removed by the shift catalyst layer 33, the CO of the fuel gas is further removed by the methanation catalyst layer 34. By removing CO by the methanation reaction, air introduction is unnecessary unlike the case of using the oxidation reaction. Thereby, the structure of the hydrogen production apparatus 10 becomes simple. Therefore, the manufacturing cost of the hydrogen production apparatus 10 can be reduced, and the hydrogen production apparatus 10 can be downsized.

With the configuration of the first to sixth cylindrical members 21 to 26 described above, the fuel gas supplied to the methanation catalyst layer 34 is cooled to an appropriate temperature. If the temperature in the methanation catalyst layer 34 exceeds a certain threshold value, CO ₂ and H ₂ react to generate heat. In this case, the temperature rises at an accelerated rate, and the methanation catalyst layer 34 may be damaged. However, since the fuel gas appropriately cooled as described above is supplied to the methanation catalyst layer 34, such an accelerated temperature increase can be suppressed.

  The preheating channel S <b> 7 is arranged so as to be related to the methanation catalyst layer 34 in the axial direction of the first cylindrical member 21. Thereby, the fuel gas that passes through the methanation catalyst layer 34 is cooled by the raw fuel gas that passes through the preheating flow path S7. Thereby, it can suppress that the temperature of fuel gas rises excessively.

  The methanation catalyst layer 34 is cooled by the raw fuel gas passing through the preheating passage S7 and is also cooled by the raw fuel gas passing through the evaporation passage S2. Thereby, the temperature of the methanation catalyst layer 34 in the radial direction can be made uniform, and the methanation reaction is favorably performed.

  The shift catalyst layer 33 is cooled by the raw fuel gas that passes through the desulfurization flow path S6 and the preheating flow path S7, and is also cooled by the raw fuel gas that passes through the evaporation flow path S2. Thereby, the temperature of the shift catalyst layer 33 in the radial direction can be made uniform, and the shift reaction is favorably performed.

  The seventh cylindrical member 27 covers a part of the fifth cylindrical member 25, so that the preheating channel S7 is formed. As a result, the fuel gas passing through the second reaction channel S5 is cooled by the raw fuel gas passing through the preheating channel S7. Therefore, the fuel gas toward the methanation catalyst layer 34 can be cooled to an appropriate temperature.

  The raw fuel gas traveling toward the desulfurization flow path S6 is heated by the fuel gas passing through the second reaction flow path S5 and approaches the temperature of the hydrodesulfurization catalyst layer 35. Thereby, it is possible to suppress the occurrence of imbalance in temperature distribution in the hydrodesulfurization catalyst layer 35 due to the raw fuel gas sprayed onto the hydrodesulfurization catalyst layer 35. Therefore, the raw fuel gas is desulfurized well.

  The preheating channel S <b> 7 is disposed so as to cover the methanation catalyst layer 34 in the axial direction of the first cylindrical member 21. Thereby, the fuel gas which passes the methanation catalyst layer 34 is cooled, and it can suppress that temperature rises excessively. Furthermore, the temperature of the methanation catalyst layer 34 is lower than the temperature of the regeneration channel S4, for example. For this reason, it is possible to suppress the raw fuel gas passing through the preheating flow path S <b> 7 from becoming a temperature higher than an appropriate temperature for the hydrodesulfurization catalyst layer 35, and the desulfurization in the hydrodesulfurization catalyst layer 35 is favorably performed.

  According to at least one embodiment described above, the CO shift catalyst layer removes carbon monoxide from the fuel gas, and the CO removal catalyst layer removes carbon monoxide from the fuel gas by methanation reaction. Thereby, the structure of the hydrogen production apparatus can be simplified.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 10 ... Hydrogen production apparatus, 13 ... Cell stack assembly (CSA), 21 ... 1st cylindrical member, 22 ... 2nd cylindrical member, 23 ... 3rd cylindrical member, 24 ... 4th Cylindrical member, 25 ... fifth cylindrical member, 26 ... sixth cylindrical member, 27 ... seventh cylindrical member, 31 ... burner, 32 ... reforming catalyst layer, 33 ... shift catalyst layer, 34 ... methanation catalyst layer , 35 ... hydrodesulfurization catalyst layer, S1 ... gap, S2 ... evaporation channel, S3 ... first reaction channel, S4 ... regeneration channel, S5 ... second reaction channel, S6 ... desulfurization channel, S7 ... Preheating channel.

Claims (4)

A first cylindrical member with one end open;
A burner that is disposed at the other end of the first cylindrical member and heats the interior of the first cylindrical member;
It is located coaxially with the first cylindrical member, accommodates at least a part of the first cylindrical member, and from one end of the first cylindrical member to the first cylindrical member. A second cylindrical member that forms a gap through which the exhaust of the burner that has exited passes;
The first cylindrical member is positioned coaxially to cover a part of the second cylindrical member in the axial direction, and between the second cylindrical member, raw fuel gas containing hydrocarbon and water are disposed. A third cylindrical member forming an evaporating flow path passing therethrough;
The raw fuel gas that is located coaxially with the first cylindrical member, covers a part of the second cylindrical member in the axial direction, and passes through the evaporation channel between the second cylindrical member And a fourth cylindrical member forming a first reaction flow path in which a reforming catalyst layer for producing a fuel gas containing hydrogen from the raw fuel gas is disposed;
Positioned coaxially with the first cylindrical member, accommodates at least a part of the third and fourth cylindrical members, and passes through the first reaction channel between the fourth cylindrical member and Forming a regeneration channel through which the fuel gas passes, and a fifth cylindrical member forming a second reaction channel connected to the regeneration channel between the third cylindrical member;
A CO shift catalyst layer that is disposed in the second reaction channel, passes through the regeneration channel, and removes carbon monoxide from the fuel gas;
A CO removal catalyst layer disposed in the second reaction flow path, through which the raw fuel gas that has passed through the shift catalyst layer passes, and removes carbon monoxide from the fuel gas by a methanation reaction;
It is located coaxially with the first cylindrical member, covers a part of the fifth cylindrical member in the axial direction, and is connected to the evaporation channel between the fifth cylindrical member and the evaporation flow A sixth cylindrical member forming a desulfurization flow path in which a hydrodesulfurization catalyst layer for desulfurizing the raw fuel gas toward the road is disposed;
Equipped with,
2. The hydrogen production apparatus according to claim 1, wherein the hydrodesulfurization catalyst layer extends between the regeneration flow path and the CO shift catalyst layer in the axial direction of the first cylindrical member . A first cylindrical member with one end open;
A burner that is disposed at the other end of the first cylindrical member and heats the interior of the first cylindrical member;
It is located coaxially with the first cylindrical member, accommodates at least a part of the first cylindrical member, and from one end of the first cylindrical member to the first cylindrical member. A second cylindrical member that forms a gap through which the exhaust of the burner that has exited passes;
The first cylindrical member is positioned coaxially to cover a part of the second cylindrical member in the axial direction, and between the second cylindrical member, raw fuel gas containing hydrocarbon and water are disposed. A third cylindrical member forming an evaporating flow path passing therethrough;
The raw fuel gas that is located coaxially with the first cylindrical member, covers a part of the second cylindrical member in the axial direction, and passes through the evaporation channel between the second cylindrical member And a fourth cylindrical member forming a first reaction flow path in which a reforming catalyst layer for producing a fuel gas containing hydrogen from the raw fuel gas is disposed;
Positioned coaxially with the first cylindrical member, accommodates at least a part of the third and fourth cylindrical members, and passes through the first reaction channel between the fourth cylindrical member and Forming a regeneration channel through which the fuel gas passes, and a fifth cylindrical member forming a second reaction channel connected to the regeneration channel between the third cylindrical member;
A CO shift catalyst layer that is disposed in the second reaction channel, passes through the regeneration channel, and removes carbon monoxide from the fuel gas;
A CO removal catalyst layer disposed in the second reaction flow path, through which the raw fuel gas that has passed through the shift catalyst layer passes, and removes carbon monoxide from the fuel gas by a methanation reaction;
It is located coaxially with the first cylindrical member, covers a part of the fifth cylindrical member in the axial direction, and is connected to the evaporation channel between the fifth cylindrical member and the evaporation flow A sixth cylindrical member forming a desulfurization flow path in which a hydrodesulfurization catalyst layer for desulfurizing the raw fuel gas toward the road is disposed;
Comprising
The raw fuel gas is located coaxially with the first cylindrical member, covers a part of the fifth cylindrical member in the axial direction, and is directed to the desulfurization passage between the fifth cylindrical member. further hydrogen production apparatus characterized by comprising a seventh cylindrical member to form a preheating passage that passes. The preheating passage, in the axial direction of said first cylindrical member, hydrogen production apparatus according to claim 2 you, characterized in that according to the CO removal catalyst layer. A hydrogen production apparatus according to any one of claims 1 to 3 ,
A fuel battery cell for generating electricity using the fuel gas produced by the hydrogen production device;
A fuel cell system comprising:

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