JP2012240893A - Hydrogen generating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen generating apparatus in which hydrogen sulfide adsorption capacity by a hydro-desulfurizer is enhanced, as compared with the conventional hydrogen generating apparatus.SOLUTION: The hydrogen generating apparatus 100 includes: a reformer 20 which brings a raw material into a reforming reaction to generate a hydrogen-containing gas; a transformer 21 which reduces the amount of CO in the hydrogen-containing gas by a shift reaction; a CO removal process 22 which reduces the amount of CO in the hydrogen-containing gas passed through the transformer 21 by at least one of a methanation reaction and an oxidation reaction; and a hydro-desulfurizer 23 which removes sulfur compounds in the raw material, wherein at least part of the downstream side of the hydro-desulfurizer 23 is adjacent to the CO removal process 22 in such a way that heat conduction can be performed.

Description

  The present invention relates to a hydrogen generator.

  In a fuel cell system, a hydrogen-containing gas is often used as a fuel gas. Therefore, it is common that a hydrogen generator is attached to the fuel cell system.

  For example, a hydrogen generator that utilizes a steam reforming reaction of a raw material causes a steam reforming reaction of the raw material to generate a hydrogen-containing gas, and supplies heat necessary for the steam reforming reaction of the reformer. And a heater. The reformer includes a noble metal catalyst such as platinum, ruthenium and rhodium or a reforming catalyst such as a Ni catalyst, and is supplied with raw materials and water and heated to a temperature suitable for the steam reforming reaction. . Then, a hydrogen-containing gas is generated by the reforming reaction of the raw material and steam by the action of the reforming catalyst. In addition, as a raw material for the reforming reaction, a hydrocarbon-based raw material such as city gas, natural gas, LPG, naphtha, gasoline, kerosene, or an alcohol-based raw material such as methanol can be used.

  By the way, in the steam reforming reaction, about 10 to 15% (dry gas base) of carbon monoxide gas (hereinafter referred to as “CO”) is generated as a subsidiary component. CO poisons the catalyst used for the electrode of a fuel cell, and reduces electric power generation capability. Therefore, in order to reduce the CO concentration in the hydrogen-containing gas, the hydrogen generator is provided with a transformer, a CO remover, and the like.

  The transformer is a device that can reduce CO in a hydrogen-containing gas by a shift reaction, and includes, for example, a catalyst for reacting CO with water vapor to transform it into hydrogen and carbon dioxide. As this catalyst, for example, a noble metal catalyst such as platinum, ruthenium or rhodium, a Cu—Zn catalyst, an Fe—Cr catalyst or the like is used. The transformer is controlled to a temperature suitable for the shift reaction, and in many cases, the CO concentration in the reformed gas is reduced to about 0.5% or less.

  The CO remover is a device that can reduce CO in the hydrogen-containing gas that has passed through the above-described converter by a methanation reaction or an oxidation reaction, and includes, for example, a selective oxidation catalyst for oxidizing CO in the reformed gas. As this selective oxidation catalyst, a noble metal catalyst such as platinum, ruthenium or rhodium is used. Then, the CO remover reduces the CO concentration in the reformed gas to 100 ppm, preferably 10 ppm or less, by performing an oxidation reaction of CO using air supplied to the inside.

  By the way, a sulfur compound is contained in source gas, such as city gas (gas supplied using piping in a city). Since the sulfur compound poisons and deteriorates the reforming catalyst in particular, it is necessary to remove the sulfur compound before supplying the raw material to the reformer. For this reason, various sulfur compound removal methods such as a room temperature desulfurization method and a hydrodesulfurization method are already known. In the above hydrodesulfurization method, hydrogen added to the raw material is used to hydrogenate the sulfur compound in the added raw material (the sulfur compound is converted to hydrogen sulfide), and this hydrogen sulfide is removed by an adsorption reaction catalyst. The process is carried out by heating the catalyst used to remove the sulfur compounds.

  Since the adsorption capacity of the sulfur compound by the hydrodesulfurization method is larger than the adsorption capacity of the sulfur compound by the room temperature desulfurization method, the hydrodesulfurization method is advantageous in the long-term operation of the hydrogen generator.

  On the other hand, when the hydrodesulfurization method is used, there is room for improvement in improving the efficiency of heat supply to the hydrodesulfurizer and making the hydrodesulfurizer compact. For this reason, a method of installing a hydrodesulfurizer concentrically around the reformer (Patent Document 1) and a method of installing a hydrodesulfurizer concentrically around the transformer (Patent Document 2) have been proposed. ing. With this configuration, it is possible to increase the efficiency of heat supply to the hydrodesulfurizer and to make the hydrodesulfurizer compact.

JP 2010-58995 A JP 2007-15911 A

  However, when a hydrodesulfurizer is installed around the reformer as in Patent Document 1, the hydrodesulfurizer is easily exposed to high temperatures.

  For example, the reformer is usually used in a temperature range of 400 ° C to 700 ° C. Then, in general, hydrogen sulfide generated by the hydrogenation reaction is chemisorbed, but the adsorption capacity becomes small. Therefore, the hydrodesulfurizer may become an obstacle to downsizing and cost reduction.

  Moreover, when the hydrodesulfurizer is installed around the transformer as in Patent Document 2, the temperature of the hydrodesulfurizer is lowered compared to the case of installing around the reformer as in Patent Document 1, There is room for improvement in the hydrogen adsorption capacity.

  This invention is made | formed in view of such a situation, and provides the hydrogen generator which the adsorption capacity of the hydrogen sulfide by a hydrodesulfurizer improves compared with the conventional hydrogen generator.

  In order to solve the above problems, a hydrogen generator of the present invention includes a reformer that reforms a raw material to generate a hydrogen-containing gas, and a transformer that reduces CO in the hydrogen-containing gas by a shift reaction. A CO remover that reduces CO in the hydrogen-containing gas that has passed through the transformer by at least one of a methanation reaction and an oxidation reaction; and a hydrodesulfurizer that removes sulfur compounds in the raw material. At least a part of the downstream side of the hydrodesulfurizer is adjacent to the CO remover so as to conduct heat.

  In the hydrogen generator of the present invention, at least a part of the upstream side of the hydrodesulfurizer may be adjacent to the transformer so as to conduct heat.

  In the hydrogen generator of the present invention, the hydrodesulfurizer may be configured to surround at least a part of the CO remover.

  In the hydrogen generator of the present invention, the hydrodesulfurizer may be configured to surround at least a part of the transformer.

  In the hydrogen generator according to the present invention, the hydrodesulfurizer may be configured so that the raw material flowing inside the hydrodesulfurizer exchanges heat sequentially with the shift converter and the CO remover.

  The hydrogen generator of the present invention may include a heater provided so as to be adjacent to the transformer and the hydrodesulfurizer.

  The hydrogen generator of the present invention may include a heater provided adjacent to the CO remover and the hydrodesulfurizer.

  In the hydrogen generator of the present invention, the hydrodesulfurizer may include a hydrogenation reaction catalyst and an adsorption reaction catalyst, and the adsorption reaction catalyst may include Cu.

  In the hydrogen generator of the present invention, the hydrodesulfurizer is adjacent to the CO remover so that the adsorption reaction catalyst containing Cu can conduct heat with at least a part of the CO remover. Also good.

  In the hydrogen generator of the present invention, the hydrodesulfurizer may include a catalyst used for both a hydrogenation reaction and an adsorption reaction, and the catalyst may include Cu.

  According to the hydrogen generator of the present invention, the adsorption capacity of hydrogen sulfide by the hydrodesulfurizer is improved as compared with the conventional hydrogen generator.

2 is a diagram illustrating an example of a hydrogen generator according to Embodiment 1. FIG. It is a figure which shows the example of examination of the adsorption characteristic of hydrogen sulfide by a hydrodesulfurizer. It is a figure which shows an example of the hydrogen generator of the modification of Embodiment 1. FIG. FIG. 3 is a diagram illustrating an example of a hydrogen generation apparatus according to a second embodiment. FIG. 6 is a diagram illustrating an example of a hydrogen generation apparatus according to a modification of the second embodiment.

(Embodiment 1)
Hereinafter, the hydrogen generator of Embodiment 1 will be described.

  The hydrogen generator of the first embodiment includes a reformer that reforms a raw material to generate a hydrogen-containing gas, a transformer that reduces CO in the hydrogen-containing gas by a shift reaction, and the gas generator that has passed through the transformer. A CO removing device that reduces CO in the hydrogen-containing gas by at least one of a methanation reaction and an oxidation reaction, and a hydrodesulfurizer that removes sulfur compounds in the raw material, downstream of the hydrodesulfurizer At least a portion of which is adjacent to the CO remover so as to conduct heat.

  With this configuration, the hydrogen sulfide adsorption capacity of the hydrodesulfurizer is improved as compared with the conventional hydrogen generator. For this reason, even if the amount of hydrodesulfurization catalyst is reduced, it is possible to secure the same amount of hydrogen sulfide adsorption as that of the conventional hydrogen generator. Can be configured compactly.

  The “downstream side of the hydrodesulfurizer” means the downstream side of the raw material flow passing through the hydrodesulfurizer.

  In the hydrogen generator of Embodiment 1, at least a part of the upstream side of the hydrodesulfurizer is adjacent to the transformer so as to be able to conduct heat.

  With this configuration, the reaction rate of the sulfur compound hydrogenation reaction by the hydrodesulfurizer is improved.

  The “upstream side of the hydrodesulfurizer” means an upstream side of the raw material flow passing through the hydrodesulfurizer.

  FIG. 1 is a diagram illustrating an example of a hydrogen generator according to Embodiment 1.

  The hydrogen generator 100 includes a reformer 20 that causes a reforming reaction of raw materials to generate a hydrogen-containing gas. Although FIG. 1 shows a configuration in which a hydrogen-containing gas can be generated from a raw material and water by a steam reforming reaction, this is an example, and other types of reforming reactions (for example, autothermal reforming reactions) are performed. It may be used.

  The raw material includes at least an organic compound having carbon and hydrogen as constituent elements. For example, the raw material includes at least one of a hydrocarbon such as city gas, natural gas, LPG, naphtha, gasoline, kerosene, and an alcohol such as methanol. One can be used.

  The reformer 20 generates CO by a side reaction of the reforming reaction. Therefore, the hydrogen generator 100 uses a shifter 21 that reduces CO in the hydrogen-containing gas by a shift reaction, and CO in the hydrogen-containing gas that has passed through the shifter 21 by at least one of a methanation reaction and an oxidation reaction. And a CO remover 22 to be reduced. In addition, sulfur gas is contained in the source gas such as city gas. Therefore, the hydrogen generator 100 includes a hydrodesulfurizer 23 that removes sulfur compounds in the raw material gas.

  With this configuration, the hydrogen generator 100 can generate a hydrogen-containing gas suitable for the fuel gas of a fuel cell (not shown), for example.

  Hereinafter, specific examples of the reformer 20, the shifter 21, the CO remover 22, and the hydrodesulfurizer 23 of the hydrogen generator 100 will be described in more detail with reference to the drawings.

  As shown in FIG. 1, the hydrogen generator 100 surrounds the combustion burner 50 attached to the upper lid 51, the combustion burner 50, the cylindrical combustion cylinder 10 provided on the upper lid 51, and the combustion cylinder 10, And a first cylinder 11 disposed concentrically on the combustion cylinder 10. The first cylinder 11 is fixed to the upper lid 51 and the bottom plate 52 and partitions the inside of the housing of the hydrogen generator 100. The combustion burner 50 is supplied with combustible gas (for example, raw material gas) and air, and high-temperature combustion exhaust gas is generated by combustible gas combustion. At this time, the region between the combustion cylinder 10 and the first cylinder 11 is used as the combustion exhaust gas flow path 31 through which the combustion exhaust gas flows.

  The combustion exhaust gas passage 31 communicates with the interior 30 of the combustion cylinder 10 through an opening at the lower end portion of the combustion cylinder 10. Therefore, the high-temperature combustion exhaust gas from the interior 30 of the combustion burner 50 is folded back by the bottom plate 52 at the lower end portion of the combustion cylinder 10 and enters the combustion exhaust gas passage 31 as indicated by the dotted line arrow in FIG. Further, the combustion exhaust gas passage 31 communicates with the outside using a combustion exhaust gas outlet 43 provided in the upper lid 36. Therefore, the combustion exhaust gas from the combustion exhaust gas passage 31 is discharged to the outside through the combustion exhaust gas outlet 43.

  As shown in FIG. 1, the hydrogen generator 100 includes a second cylinder 12 that surrounds the first cylinder 11 and is disposed concentrically with the combustion cylinder 10.

  The 1st cylinder 11 and the 2nd cylinder 12 comprise the inner wall and outer wall of the evaporator 32 which evaporate the water from the water inlet 42, respectively. Further, the first cylinder 11 and the second cylinder 12 constitute an inner wall and an outer wall of the reformer 20 that generates a hydrogen-containing gas by causing a raw material gas to undergo a steam reforming reaction below the evaporator 32, respectively. . That is, the reformer 20 and the evaporator 32 are arranged in this order along the flow direction of the flue gas in the flue gas passage 31.

  In this way, the reformer 20 is adjacent to the combustion exhaust gas flow channel 31 so as to be able to conduct heat with the combustion exhaust gas immediately after flowing into the combustion exhaust gas flow channel 31 via the first cylinder 11, and the evaporator 32. Is adjacent to the flue gas passage 31 so as to be able to conduct heat with the flue gas after heat exchange with the reformer 20 via the first cylinder 11.

  With this configuration, the evaporator 32 can evaporate water from the water inlet 42 and heat the raw material gas by the heat transfer effect of the combustion exhaust gas. Then, the raw material gas and water vapor are mixed, and the mixed gas is supplied to the reformer 20. On the other hand, the reformer 20 can generate a reformed gas (hydrogen-containing gas) containing hydrogen as a main component by advancing a steam reforming reaction of the raw material gas with the reforming catalyst.

  As shown in FIG. 1, the hydrogen generator 100 includes a third cylinder 13 that surrounds the second cylinder 12 and is arranged concentrically with the combustion cylinder 10.

  Each of the second cylinder 12 and the third cylinder 13 constitutes an inner wall and an outer wall of a transformer 22 that reduces CO in the hydrogen-containing gas from the reformer 20 by a shift reaction. In addition, the second cylinder 12 and the third cylinder 13 respectively reduce CO in the hydrogen-containing gas that has passed through the transformer 21 by at least one of a methanation reaction and an oxidation reaction above the transformer 21. An inner wall and an outer wall of the CO remover 22 are configured. That is, the transformer 21 and the CO remover 22 are arranged in this order along the flow direction of the flue gas in the flue gas passage 31 above the reformer 20.

  In this way, the transformer 21 is adjacent to the evaporator 32 through the second cylinder 12 so as to be able to conduct heat with the combustion exhaust gas in the combustion exhaust gas passage 31, and the CO remover 22 is connected to the second cylinder. It is adjacent to the evaporator 32 through the body 12 so as to be able to conduct heat with the combustion exhaust gas after heat exchange with the transformer 21.

  As described above, the transformer 21 can advance the shift reaction between CO and water in the hydrogen-containing gas with the shift reaction catalyst, and can reduce the concentration of CO in the hydrogen-containing gas. Further, when a methanation reaction is used for CO removal, the CO remover 22 can advance the reaction of CO and hydrogen in the hydrogen-containing gas with a CO methanation catalyst, thereby reducing the concentration of CO in the hydrogen-containing gas. (For example, 100 ppm or less). However, in this case, hydrogen in the hydrogen-containing gas is used for the CO methanation reaction. Further, when the CO oxidation reaction is used for CO removal, the CO remover 22 advances the reaction between CO in the hydrogen-containing gas and oxygen in the air by using a CO oxidation catalyst, thereby reducing the concentration of CO in the hydrogen-containing gas. Can be reduced (for example, 100 ppm or less). However, in this case, it is necessary to separately supply the CO oxidation reaction air to the CO remover 22.

  As shown in FIG. 1, the hydrogen generator 100 includes a fourth cylinder 14 that surrounds the third cylinder 13 and is arranged concentrically with the combustion cylinder 10.

The third cylinder 13 and the fourth cylinder 14 respectively constitute an inner wall and an outer wall of a hydrodesulfurizer 23 that removes sulfur compounds in the raw material gas. The hydrodesulfurizer 23 includes a catalyst for hydrogenation reaction and an adsorption reaction (specific examples will be described later). On the upstream side of the hydrodesulfurizer 23, the sulfur compound in the raw material gas is reacted with hydrogen and converted into hydrogen sulfide (H ₂ S) by a hydrogenation reaction catalyst (hydrogenation reaction). On the downstream side of the hydrodesulfurizer 23, hydrogen sulfide is chemically adsorbed by the adsorption reaction catalyst. In this way, the sulfur compound in the raw material gas is removed in the hydrodesulfurizer 23.

  Here, the hydrodesulfurizer 23 is adjacent via the third cylinder 13 so that at least a part of the downstream side thereof can conduct heat with the CO remover 22, and via the third cylinder 13. At least a part of the upstream side is adjacent to the transformer 21 so as to conduct heat.

  Thereby, the hydrodesulfurizer 23 is configured such that the raw material gas flowing inside the hydrodesulfurizer 23 exchanges heat with the shift converter 21 and the CO remover 22 in order.

  In this example, the hydrodesulfurizer 23 surrounds the entire CO remover 22 and also surrounds the entire transformer 21, but this is merely an example. The hydrodesulfurizer 23 may surround at least a part of the CO remover 22 and may surround at least a part of the transformer 21.

Further, in this example, the hydrodesulfurizer 23 is configured in a ring shape in which the hollow of the hydrodesulfurizer 23 extends in the axial direction by the third cylinder 13 and the fourth cylinder 14 having a double pipe structure. The CO remover 22 is configured in an annular shape including the cross sections of the second cylinder 12 and the third cylinder 13 having a double tube structure.
However, the shape of the hydrodesulfurizer 23 may be configured such that a catalyst for hydrodesulfurization is filled inside a hollow cylindrical structure. That is, the shape of the hydrodesulfurizer 23 may be either cylindrical or annular.
Similarly, the shape of the CO remover 22 may be configured such that a hollow tubular structure is filled with a catalyst for the CO remover. That is, the shape of the CO remover 22 may be either cylindrical or annular.

  Alternatively, the catalyst for hydrodesulfurization may be filled into a single tube hollow, and the downstream side of this single tube may be disposed adjacent to the CO remover 22 (not shown).

  In this example, the upstream side of the hydrodesulfurizer 23 is adjacent to the transformer 21 so as to be able to conduct heat. However, the upstream configuration of the hydrodesulfurizer 23 is arbitrary, and other configurations may be used. Other configuration examples will be described later in a modification.

  As shown in FIG. 1, the lower region between the third cylinder 13 and the fourth cylinder 14 communicates with the gas inlet line 40 through an opening at the lower end of the fourth cylinder 14. For this reason, the raw material gas led to the gas inlet line 40 can be passed through the hydrodesulfurizer 23 as shown by the thick arrows in FIG. 1, and as a result, the sulfur compound in the raw material gas can be removed.

  The upper region between the first cylinder 11 and the second cylinder 12 (the region constituting the evaporator 32) is the third through the openings at the upper ends of the second cylinder 12 and the third cylinder 13. It communicates with the upper region between the cylinder 13 and the fourth cylinder 14. For this reason, the raw material gas from the hydrodesulfurizer 23 is folded back by the upper lid 51 at the upper ends of the second cylinder 12 and the third cylinder, as indicated by the thick arrows in FIG. 1, and the first cylinder 11 and the second cylinder It enters the region between the bodies 12 (the region constituting the evaporator 32 and the reformer 20).

  Thereby, the source gas can be passed through the evaporator 32 and the reformer 20, and as a result, a hydrogen-containing gas can be generated from the source gas and water vapor.

  Further, a lower region between the first cylinder 11 and the second cylinder 12 (an area constituting the reformer 20) is connected to the second cylinder 12 and the second cylinder via an opening in the lower end portion of the second cylinder 12. It communicates with the lower region between the three cylinders 13. For this reason, the hydrogen-containing gas from the reformer 20 is folded by the bottom plate 52 at the lower end of the second cylinder 12 as shown by the thick arrow in FIG. 1, and is an area between the second cylinder 12 and the third cylinder 13. to go into.

  Thereby, the hydrogen-containing gas can be passed through the transformer 21 and the CO remover 22, and as a result, CO in the hydrogen-containing gas can be removed.

  Further, the upper region between the second cylinder 12 and the third cylinder 13 communicates with the gas outlet line 41 through an opening at the upper end of the third cylinder 13. For this reason, the hydrogen-containing gas from the CO remover 22 can be sent out of the hydrogen generator 100 as indicated by the thick arrows in FIG. 1, and as a result, the hydrogen-containing gas from which the CO has been removed can be used as, for example, a fuel cell. Etc. can be supplied.

  As shown in FIG. 1, the gas inlet line 40 and the gas outlet line 41 communicate with each other via a recycle line 45. A flow rate regulator (not shown) capable of adjusting the distribution flow rate of the hydrogen-containing gas is provided at a connection portion between the gas outlet line 41 and the recycle line 45. Therefore, a part of the hydrogen-containing gas from the gas outlet line 41 flows through the recycle line 45 as shown by the thin arrows in FIG. 1, and this hydrogen-containing gas can be mixed with the raw material gas in the gas inlet line 40. Thereby, hydrogen used for hydrogenation of the sulfur compound in the raw material gas can be supplied to the hydrodesulfurizer 23.

  In this example, the example in which the recycle line 45 is used to mix the hydrogen-containing gas from the CO remover 22 with the raw material gas in the gas inlet line 40 has been described, but the present invention is not limited thereto. For example, the hydrogen-containing gas from the transformer 21 may be used for mixing with the raw material gas in the gas inlet line 40. In this case, it is preferable that a recycle line (not shown) capable of supplying a hydrogen-containing gas on the downstream side of the transformer 21 communicates with the gas inlet line 40 to mix both gases.

  That is, the recycle line may have any configuration as long as it has a piping structure that can mix at least the hydrogen-containing gas existing on the downstream side of the transformer 21 with the raw material gas in the gas inlet line 40.

  As shown in FIG. 1, the hydrogen generator 100 includes a controller 60 including an arithmetic processing unit that executes a control program of the hydrogen generator 100 and a storage unit that stores the control program. The controller 60 may be composed of a single controller or a plurality of controllers. In addition, the said arithmetic processing part is comprised by CPU, MPU, etc. The storage unit includes a memory or the like.

  In the hydrogen generator 100, the controller 60 outputs a signal from a detector (not shown) that can detect the temperatures of the reformer 20, the shift converter 21, the CO remover 22, and the hydrodesulfurizer 23. Based on the various control objects (for example, pumps not shown) of the hydrogen generator 100 so that the temperatures of the reformer 20, the shift converter 21, the CO remover 22, and the hydrodesulfurizer 23 can be adjusted to appropriate temperatures. And the operation of the flow control valve, etc.).

  In this embodiment, a Ru-based catalyst is used as the reforming catalyst of the reformer 20, and the temperature on the upstream side of the reformer 20 is reformed to, for example, about 400 ° C. by heat transfer action from the combustion exhaust gas. The reformer 20 is heated so that the temperature on the downstream side of the vessel 20 is, for example, about 600 ° C.

  Further, a CuZn-based catalyst is used as the catalyst of the transformer 21, and the temperature on the upstream side of the transformer 21 is set to, for example, about 300 ° C. by the heat transfer action from the combustion exhaust gas. For example, the transformer 21 is heated to about 200 ° C.

  In addition, a Ru-based catalyst that is an example of a methanation catalyst is used as the catalyst of the CO remover 22, and the temperature of the CO remover 21 becomes, for example, about 150 ° C. to 200 ° C. due to heat transfer from the combustion exhaust gas. Thus, the CO remover 22 is heated.

  Further, as the catalyst of the hydrodesulfurizer 23, a CuZn-based catalyst is used. The temperature on the upstream side of the hydrodesulfurizer 23 is, for example, about 300 ° C., and the temperature on the downstream side of the hydrodesulfurizer 23 is, for example, The hydrodesulfurizer 23 is heated to about 150 ° C. That is, the hydrodesulfurizer 23 includes a catalyst (for example, a CuZn-based catalyst) used for both the hydrogenation reaction and the adsorption reaction, and this catalyst includes Cu.

  Such a single-layer CuZn-based catalyst is an example of a catalyst for the hydrodesulfurizer 23 and the shift converter 21 and is not limited to this example.

  For example, the hydrodesulfurizer 23 includes a hydrogenation reaction catalyst (for example, a CoMo-based catalyst) and an adsorption reaction catalyst (for example, a CuZn-based catalyst), and the adsorption reaction catalyst includes Cu. There may be.

  Further, as the catalyst of the transformer 21, for example, a catalyst made of a noble metal such as Pt may be used. However, as in this example, when the catalyst of the hydrodesulfurizer 23 and the catalyst of the shift converter 21 are made of the same element as much as possible, these operating temperature ranges can be made closer, and the hydrodesulfurizer 23 There is an advantage that the effect obtained by adjoining the transformer 21 and the transformer 21 is easily exhibited.

  By the way, it is preferable that the upstream side of the hydrodesulfurizer 23 has a higher temperature than the downstream side of the hydrodesulfurizer 23 in terms of improving the reaction rate of the hydrogenation reaction. However, when a CuZn-based catalyst is used as the catalyst of the hydrodesulfurizer 23, the upper limit of the temperature on the upstream side of the hydrodesulfurizer 23 is about 300 ° C. in consideration of the durability of the catalyst.

  On the other hand, the downstream side of the hydrodesulfurizer 23 is preferably at a lower temperature than the upstream side of the hydrodesulfurizer 23 in terms of improving the hydrogen sulfide adsorption capacity. Specifically, when the temperature on the downstream side of the hydrodesulfurizer 23 is about 150 ° C. to 200 ° C., the adsorption capacity of hydrogen sulfide increases. And such knowledge is verified by the following examination examples.

  FIG. 2 is a diagram showing an example of examining hydrogen sulfide adsorption characteristics by a hydrodesulfurizer.

  The horizontal axis in FIG. 2 represents the elapsed time (unit: 1 hour (h)) from the time when hydrogen sulfide was introduced into the hydrodesulfurizer, and the vertical axis in FIG. 2 was hydrogen sulfide at the outlet of the hydrodesulfurizer. Concentration (unit: ppb). FIG. 2 shows the concentration change profile of hydrogen sulfide when the temperature of the hydrodesulfurizer is set to 150 ° C., 200 ° C., and 250 ° C., respectively.

  In this example, a CuZn-based catalyst is used as a catalyst for the hydrodesulfurizer, and a gas chromatograph analyzer (FPD (flame photometric detector) -14 manufactured by Shimadzu Corporation) is used to measure the concentration of hydrogen sulfide. )).

  As shown in FIG. 2, when the temperature of the hydrodesulfurizer is 150 ° C. and 200 ° C., the concentration profile of hydrogen sulfide rises after about 16.5 hours from the introduction of hydrogen sulfide. On the other hand, when the temperature of the hydrodesulfurizer is 250 ° C., the concentration profile of hydrogen sulfide rises early (after about 14.5 hours) from the introduction of hydrogen sulfide. For this reason, it can be understood from the results of FIG. 2 that when the temperature of the hydrodesulfurizer is 250 ° C., the early decrease in the adsorption capacity of hydrogen sulfide appears remarkably.

  Therefore, by setting the temperature on the downstream side of the hydrodesulfurizer to about 150 ° C. to 200 ° C., the hydrogen sulfide adsorption capacity by the hydrodesulfurizer is reduced to the sulfurization when the temperature of the hydrodesulfurizer 23 is 250 ° C. It is thought that it can be larger than the adsorption capacity of hydrogen.

  Therefore, as described above, the hydrogen generator 100 is configured such that at least a part of the downstream side of the hydrodesulfurizer 23 is adjacent to the CO remover 22 so as to conduct heat. Further, at least a part of the upstream side of the hydrodesulfurizer 23 is configured to be adjacent to the transformer 21 so as to be able to conduct heat.

  With this configuration, the temperature on the downstream side of the hydrodesulfurizer 23 can be set close to the temperature of the CO remover 22 (about 150 ° C. to 200 ° C.), so that the hydrogen sulfide adsorption capacity by the hydrodesulfurizer 23 can be improved. . Moreover, since the temperature on the upstream side of the hydrodesulfurizer 23 can be set close to the temperature of the transformer 21 (about 200 ° C. to 300 ° C.), the hydrodesulfurizer 23 performs the hydrogenation reaction of the sulfur compound in the raw material gas. The reaction rate can be improved. That is, on the upstream side of the hydrodesulfurizer 23, hydrogenation of sulfur compounds proceeds rapidly, and on the downstream side of the hydrodesulfurizer 23, the adsorption capacity of hydrogen sulfide increases.

Thus, in the hydrogen generator 100, the hydrogen sulfide adsorption capacity by the hydrodesulfurizer 23 is improved as compared with the conventional hydrogen generator. For this reason, even if the amount of the catalyst of the hydrodesulfurizer 23 is reduced, the hydrogen sulfide adsorption amount equivalent to that of the conventional hydrogen generator can be ensured. Therefore, the hydrogen generator 100 is compared with the conventional hydrogen generator, The manufacturing cost can be suppressed and the configuration can be made compact.
[Modification]
Hereinafter, the hydrogen generator of the modification of Embodiment 1 is demonstrated.

  FIG. 3 is a diagram illustrating an example of a hydrogen generation apparatus according to a modification of the first embodiment.

  As shown in FIG. 3, the hydrodesulfurizer 123 of the hydrogen generator 100A includes a downstream portion 123D, an upstream portion 123U, and a communication pipe 123C that communicates the downstream portion 123D and the upstream portion 123U. The upstream portion 123U of the hydrodesulfurizer 123 includes a hydrogenation reaction catalyst (for example, a CoMo-based catalyst or a CuZn-based catalyst). On the other hand, the downstream portion 123D of the hydrodesulfurizer 123 contains a catalyst for adsorption reaction (for example, a CuZn-based catalyst).

  As shown in FIG. 3, at least a part of the downstream portion 123 </ b> D of the hydrodesulfurizer 123 is adjacent to the CO remover 22 so as to conduct heat.

  Thereby, the temperature of the downstream part 123D of the hydrodesulfurizer 123 can be set close to the temperature of the CO remover 22 (about 150 ° C. to 200 ° C.).

  Further, at least a part of the upstream portion 123U of the hydrodesulfurizer 123 can conduct heat with the upstream side of the reformer 20 via the region between the second cylinder 12 and the third cylinder 13. Adjacent to.

  Thereby, the temperature of the upstream part 123U of the hydrodesulfurizer 123 can be set to a temperature (for example, about 300 ° C.) slightly lower than the temperature (for example, 400 ° C.) upstream of the reformer 20.

About points other than the above, you may comprise similarly to the hydrogen generator 100 of Embodiment 1. FIG.
(Embodiment 2)
Hereinafter, the hydrogen generator of Embodiment 2 will be described.

  The hydrogen generator of Embodiment 2 includes a heater provided adjacent to the transformer and the hydrodesulfurizer.

  With this configuration, when the hydrogen generator is started, the temperature of the transformer and the hydrodesulfurizer can be quickly increased using a heater, so that the startup time of the hydrogen generator can be shortened.

  FIG. 4 is a diagram illustrating an example of the hydrogen generation apparatus according to the second embodiment.

  As shown in FIG. 4, the hydrogen generator 200 includes a heater 201 provided so as to be adjacent to the transformer 21 and the hydrodesulfurizer 23. The heater 201 is arranged concentrically with the transformer 21 so as to surround the transformer 21. The hydrodesulfurizer 23 is arranged concentrically with the heater 201 so as to surround the heater 201. Moreover, in this example, the heater 201 is wound between the outer wall of the transformer 21 and the inner wall of the hydrodesulfurizer 23 in a coil shape so as to contact both walls.

  When the hydrogen generator 200 is started, the temperature of the transformer 21 is low. Therefore, the transformer 21 has not reached the temperature at which the shift reaction for removing CO proceeds, and thus the transformer 21 does not exhibit the function of removing CO.

  Thus, in this example, when the hydrogen generator 200 is started, the transformer 21 is heated using the heater 201, so that the temperature of the transformer 21 can be quickly raised to a temperature at which CO can be appropriately removed. . Thereby, the hydrogen-containing gas from which CO is removed by the transformer 21 can be quickly generated, and as a result, the startup time of the hydrogen generator 200 can be shortened.

  In this case, the controller 60 controls the operation of the heater 201 based on a signal from a detector (not shown) that can detect the temperature of the transformer 21.

  On the other hand, when the hydrogen generator 200 is started, the temperature of the hydrodesulfurizer 23 is low. The hydrodesulfurizer 23 does not exhibit desulfurization performance unless the temperature is raised to a predetermined temperature. For example, when a CuZn-based catalyst is used as the catalyst of the hydrodesulfurizer 23, the desulfurization performance is exhibited in a temperature range of about 150 ° C to 300 ° C.

  Therefore, in this example, when the hydrogen generator 200 is started, the hydrodesulfurizer 23 is heated using the heater 201, so that the temperature of the hydrodesulfurizer 23 is reduced to a temperature at which sulfur compounds can be appropriately removed. The temperature can be raised quickly. Thereby, the raw material gas from which the sulfur compound is removed by the hydrodesulfurizer 23 can be quickly generated, and as a result, the startup time of the hydrogen generator 200 can be shortened.

  In this case, the controller 60 controls the operation of the heater 201 based on a signal from a detector (not shown) that can detect the temperature of the hydrodesulfurizer 23.

  After a sufficient time has elapsed since the start of the hydrogen generator 200, even if the heating operation of the heater 201 is stopped due to the heat transfer of the combustion exhaust gas from the combustion burner 50, the transformer 21 and water Each temperature of the addition desulfurizer 23 can be maintained at a temperature at which these functions can be sufficiently exhibited. In this case, even if the heating operation of the heater 201 is stopped, for example, the temperature of the transformer 21 is set to about 300 ° C., the upstream temperature of the hydrodesulfurizer 23 is set to about 300 ° C., and the hydrodesulfurizer 23 The downstream temperature can be maintained at about 150 ° C., respectively. Therefore, even after the heating operation of the heater 201 is stopped, the temperature distribution effective for the desulfurization performance of the hydrodesulfurizer 23 can be given to the hydrodesulfurizer 23 in the present embodiment as in the first embodiment. As a result, the hydrodesulfurizer 23 exhibits its desulfurization performance effectively.

About a point other than the above, you may comprise similarly to the hydrogen generator in any one of Embodiment 1 and the modification of Embodiment 1.
[Modification]
Hereinafter, the hydrogen generator of the modified example of Embodiment 2 is demonstrated.

  The hydrogen generator of the modification of Embodiment 2 includes a heater provided so as to be adjacent to the CO remover and the hydrodesulfurizer.

  With this configuration, when the hydrogen generator is started, the temperature of the CO remover and the hydrodesulfurizer can be quickly increased using a heater, so that the startup time of the hydrogen generator can be shortened.

  FIG. 5 is a diagram illustrating an example of a hydrogen generation apparatus according to a modification of the second embodiment.

  As shown in FIG. 5, the hydrogen generator 200 </ b> A includes a heater 202 provided so as to be adjacent to the CO remover 22 and the hydrodesulfurizer 23. FIG. 5 shows an example in which the heater 202 is also adjacent to the transformer 21. That is, the heater 202 is arranged concentrically with the CO remover 22 and the transformer 21 so as to surround both the CO remover 22 and the transformer 21. The hydrodesulfurizer 23 is disposed concentrically with the heater 202 so as to surround the heater 202. Further, in this example, the heater 202 is wound in a coil shape between the outer wall of the CO remover 22 and the transformer 21 and the inner wall of the hydrodesulfurizer 23 so as to contact both walls.

  When the hydrogen generator 200A is activated, the temperatures of the CO remover 22 and the transformer 21 are low. Therefore, the CO remover 22 and the transformer 21 have not reached the temperature at which the reaction for removing CO proceeds, and the CO remover 22 and the transformer 21 do not exhibit the function of removing CO.

  Therefore, in this example, when the hydrogen generator 200A is started, the CO remover 22 and the transformer 21 are heated using the heater 202, whereby the respective temperatures of the CO remover 22 and the transformer 21 are changed to CO. The temperature can be quickly raised to a temperature that can be removed appropriately. Thereby, the hydrogen-containing gas from which CO has been removed by the CO remover 22 and the transformer 21 can be quickly generated, and as a result, the startup time of the hydrogen generator 200A can be shortened.

  In this case, the controller 60 controls the operation of the heater 202 based on a signal from a detector (not shown) that can detect the temperatures of the CO remover 22 and the transformer 21.

  On the other hand, as in the second embodiment, by heating the hydrodesulfurizer 23 using the heater 202, the temperature of the hydrodesulfurizer 23 can be quickly raised to a temperature at which sulfur compounds can be removed appropriately. . Thereby, the raw material gas from which the sulfur compound is removed by the hydrodesulfurizer 23 can be quickly generated, and as a result, the startup time of the hydrogen generator 200A can be shortened.

  In this case, the controller 60 controls the operation of the heater 202 based on a signal from a detector (not shown) that can detect the temperature of the hydrodesulfurizer 23.

  Note that after a sufficient time has elapsed since the start of the hydrogen generator 200A, even if the heating operation of the heater 202 is stopped due to the heat transfer of the combustion exhaust gas from the combustion burner 50, the CO remover 22, Each temperature of the transformer 21 and the hydrodesulfurizer 23 can be maintained at a temperature at which these functions can be sufficiently exhibited. In this case, even if the heating operation of the heater 202 is stopped, for example, the temperature of the transformer 21 is about 300 ° C., the temperature of the CO remover 22 is about 150 ° C., and the temperature upstream of the hydrodesulfurizer 23. Can be maintained at about 300 ° C., and the downstream temperature of the hydrodesulfurizer 23 can be maintained at about 150 ° C., respectively. Therefore, even after the heating operation of the heater 202 is stopped, as in the first embodiment, in the modification of the present embodiment, a temperature distribution effective for the desulfurization performance of the hydrodesulfurizer 23 is given to the hydrodesulfurizer 23. As a result, the hydrodesulfurizer 23 exhibits its desulfurization performance effectively.

  About a point other than the above, you may comprise similarly to the hydrogen generator in any one of Embodiment 1 and the modification of Embodiment 1.

  According to the hydrogen generator of the present invention, the adsorption capacity of hydrogen sulfide by the hydrodesulfurizer is improved as compared with the conventional hydrogen generator. Therefore, the present invention can be used for a hydrogen generator.

DESCRIPTION OF SYMBOLS 10 Combustion cylinder 11 1st cylinder 12 2nd cylinder 13 3rd cylinder 14 4th cylinder 20 Reformer 21 Transformer 22 CO remover 23 Hydrodesulfurizer 31 Combustion exhaust gas flow path 32 Evaporator 50 Combustion burner 40 Gas inlet line 41 Gas outlet line 42 Water inlet 43 Combustion exhaust gas outlet 45 Recycling line 50 Combustion burner 51 Top lid 52 Bottom plate 60 Controller 201, 202 Heater 100, 100A, 200, 200A Hydrogen generator

Claims (10)

A reformer that reforms the raw material to produce a hydrogen-containing gas;
A transformer that reduces CO in the hydrogen-containing gas by a shift reaction;
A CO remover that reduces CO in the hydrogen-containing gas that has passed through the transformer by at least one of a methanation reaction and an oxidation reaction;
A hydrodesulfurizer that removes sulfur compounds in the raw material;
A hydrogen generator comprising:
At least a part of the downstream side of the hydrodesulfurizer is adjacent to the CO remover so as to be able to conduct heat. 2. The hydrogen generator according to claim 1, wherein at least a part of the upstream side of the hydrodesulfurizer is adjacent to the transformer so as to conduct heat.   The hydrogen generation apparatus according to claim 1, wherein the hydrodesulfurizer is configured to surround at least a part of the CO remover.   The hydrogen generation apparatus according to claim 1, wherein the hydrodesulfurizer is configured to surround at least a part of the transformer.   The hydrogen generation according to any one of claims 1 to 4, wherein the hydrodesulfurizer is configured so that a raw material flowing inside the hydrodesulfurizer exchanges heat sequentially with the transformer and the CO remover. apparatus.   The hydrogen generator according to claim 2, further comprising a heater provided adjacent to the transformer and the hydrodesulfurizer.   The hydrogen generator according to claim 2, further comprising a heater provided adjacent to the CO remover and the hydrodesulfurizer. The hydrogen generation apparatus according to claim 1 or 2, wherein the hydrodesulfurizer includes a hydrogenation reaction catalyst and an adsorption reaction catalyst, and the adsorption reaction catalyst includes Cu. 9. The hydrogen according to claim 8, wherein the hydrodesulfurizer is adjacent to the CO remover so that the adsorption reaction catalyst containing Cu can conduct heat with at least a part of the CO remover. Generator.   The hydrogen generation apparatus according to claim 1, wherein the hydrodesulfurizer includes a catalyst used for both a hydrogenation reaction and an adsorption reaction, and the catalyst includes Cu.

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