JP5807167B2 - Hydrogen generator - Google Patents

Description

  The present invention relates to a hydrogen generator, and more particularly to a hydrogen generator equipped with a hydrodesulfurizer that is incorporated in a fuel cell power generator and removes sulfur compounds contained in hydrocarbon-based source gas.

  In a fuel cell power generation device, hydrogen, which is a fuel, is generated by reforming a gas source composed of a hydrocarbon gas mainly composed of methane such as LP gas and natural gas and water vapor by a hydrogen generator. The The generated hydrogen is supplied to the fuel electrode of the fuel cell to generate power. In the hydrogen generator, the raw material gas is reformed into a hydrogen-rich gas by a reforming reaction in the fuel reformer. The generation of hydrogen supplied from a hydrocarbon to a fuel cell in this way is called reforming. Carbon monoxide generated simultaneously with hydrogen in the reforming reaction significantly reduces the power generation characteristics of the stack, which is the power generation unit. In order to prevent this, a carbon monoxide purifier that generates carbon monoxide shift reaction, selective oxidation reaction, etc., the carbon monoxide is removed from the hydrogen-rich gas after reforming, and its content rate is reduced. The

  A steam reforming method is generally employed for reforming the raw material gas. Specifically, using a metal catalyst such as Pt (platinum), Ni (nickel), and Ru (ruthenium) as the reforming catalyst, the reaction is caused at about 600 to 700 ° C. Further, a CuZn (copper zinc) system is used as a catalyst for causing the carbon monoxide shift reaction, and the reaction is caused to occur at 150 to 350 ° C. As a catalyst that causes a selective oxidation reaction, a Pt-based or Ru-based catalyst is used, and the reaction is caused at 80 to 200 ° C.

  An organic sulfur compound is added as an odorant to a source gas such as city gas, LP gas, and natural gas. Since the reforming catalyst is poisoned by the sulfur compound and deteriorates its performance, a desulfurization step is provided as a pretreatment for passing the raw material gas through the reforming catalyst in order to remove the sulfur compound in the raw material gas to an allowable concentration or less. There is a need.

  As one of the desulfurization methods for removing the sulfur compound in the raw material gas, there is a hydrodesulfurization method in which hydrogen is mixed into the raw material gas to remove the sulfur compound. In the hydrodesulfurization method, since the adsorption capacity of sulfur is large, it is not necessary to replace the adsorbent over a long period of time. On the other hand, since hydrogen is required for the hydrodesulfurization type desulfurization reaction, a part of the reformed gas generated by the reforming catalyst is added to the raw material gas and supplied to the hydrodesulfurizer.

  In the hydrodesulfurizer, sulfur compounds react with hydrogen and are removed by a hydrodesulfurization catalyst. At this time, the temperature at which an appropriate reaction occurs in the catalyst depends on the type of catalyst, but it is necessary to keep the catalyst at a high temperature of about 200 ° C to 400 ° C. As the hydrodesulfurization catalyst, CuZn-based, Ni-based, CoMo (cobalt / molybdenum) -based, ZnO (zinc oxide) -based, or the like is used.

  FIG. 8 shows a hydrodesulfurizer-integrated cylindrical steam reformer proposed in Patent Document 1 as an example of a conventional hydrogen generator. In short, the hydrodesulfurizer-integrated cylindrical steam reformer GHc is configured by integrating a hydrodesulfurizer into a hydrogen generator. Specifically, the hydrodesulfurizer 200 is incorporated in the lower part of the hydrogen generator main body 201 where the transformer 202 is located and on the outer periphery where the reformer 203 is located. The reason why it is arranged on the outer periphery of the reformer 203 is to keep the hydrodesulfurization catalyst 204 at a temperature suitable for the reaction by utilizing the heat of the reformer 203 that becomes a high temperature of about 600 ° C.

  The reaction vessel of the hydrodesulfurizer 200 has a concentric double cylindrical shape, and the upper and lower end surfaces of the space surrounded by the outer cylinder 205 and the inner cylinder 206 are closed with a hollow double cylindrical upper surface plate 207 and a bottom surface plate 208. This is a mold container. The hydrodesulfurization catalyst 204 is filled between the partition plates 209 arranged above and below in the reaction vessel. An upper header 210 is formed between the upper surface plate 207 and the hydrodesulfurization catalyst 204 on the upper side in the reaction vessel with the catalyst layer interposed therebetween, and between the bottom plate 208 and the hydrodesulfurization catalyst 204 on the lower side. A lower header 211 is formed.

  The top plate 207 is connected to a source gas discharge pipe 212 for discharging desulfurized source gas, and the bottom plate 208 is connected to a source gas supply pipe 213 for supplying a source gas added with hydrogen from below. Yes. The raw material gas to which hydrogen is added is introduced into the lower header 211 from the raw material gas supply pipe 213, and the sulfur compound in the raw material gas is subjected to a desulfurization reaction with hydrogen in the process of raising the catalyst layer (hydrodesulfurization catalyst 204). Removed. The raw material gas from which the sulfur compound has been removed reaches the upper header 210 and passes through the raw material gas discharge pipe 212 to the reformer 203.

JP 2010-58995 A

  In the hydrodesulfurizer-integrated cylindrical steam reformer GHc (hydrogen generator) configured as described above, since the hydrodesulfurizer 200 is directly connected to the raw material gas supply pipe 213, the hydrodesulfurizer 200 GHc Compared with the operating temperature of the hydrodesulfurization catalyst 204 which is as high as about 400 ° C., a raw material gas which is much lower in temperature (25 ° C. at normal temperature) is introduced into the hydrodesulfurizer 200. That is, in the vicinity of the raw material gas supply pipe 213 and the outlet of the hydrodesulfurizer 200, the raw material gas flows as low as 175 ° C. to 275 ° C. compared to the appropriate temperature (200 ° C. to 400 ° C.). The soaking zone inside the desulfurizer 200 is broken or the portion is excessively cooled, so that the entire catalyst layer cannot be kept in an appropriate temperature range. And the desulfurization reaction in the hydrodesulfurizer 200 may be impaired, or in the worst case, the hydrodesulfurizer 200 may be damaged by thermal shock. As a result, the raw material gas from which the sulfur compound is not sufficiently removed is supplied to the reaction vessel.

  In view of the above problems, an object of the present invention is to provide a hydrogen generator capable of supplying a raw material gas to a hydrodesulfurizer while suppressing a difference from the operating temperature of the hydrodesulfurizer.

In order to solve the above problems, the present invention is a hydrogen generator,
A cylindrical reformer that generates a hydrogen-containing gas by a reforming reaction using a raw material gas;
A cylindrical carbon monoxide purifier that reduces carbon monoxide in the hydrogen-containing gas produced by the reformer;
A cylindrical hydrodesulfurizer that is provided on the outer periphery of the reformer and removes sulfur compounds in the raw material gas;
A source gas supply path through which source gas supplied to the hydrodesulfurizer flows,
The raw material gas supply path is arranged so as to be capable of exchanging heat along the outer peripheral surface of the carbon monoxide purifier, and the first heat exchange extending parallel to the central axis of the carbon monoxide purifier And a second heat exchanging portion extending by a length defined by a predetermined central angle in the outer peripheral direction .

  According to the hydrogen generator of the present invention, it is possible to supply a raw material gas having an appropriate temperature to the hydrodesulfurizer.

It is a longitudinal cross-sectional view which shows the internal structure of the hydrogen generator which concerns on Embodiment 1 of this invention. It is a fragmentary perspective view which shows the external appearance structure of the hydrogen generator of FIG. It is a fragmentary perspective view which shows the external appearance structure of the hydrogen generator which concerns on Embodiment 2 of this invention. It is a longitudinal cross-sectional view which shows the internal structure of the hydrogen generator based on Embodiment 3 of this invention. It is a fragmentary perspective view which shows the external appearance structure of the hydrogen generator which concerns on Embodiment 4 of this invention. It is a figure which shows the temperature measurement point in the actual machine experiment of the hydrogen generator based on this invention. It is a figure which shows the measurement temperature in each measurement point shown in FIG. It is sectional drawing which shows the structure of the conventional hydrogen generator.

  Hereinafter, hydrogen generators according to Embodiments 1 to 4 of the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5, 6, and 7. Note that, in different embodiments, the same or similar members are in principle given the same reference numerals and description thereof is omitted.

(Embodiment 1)
FIG. 1 shows the internal structure of the hydrogen generator according to Embodiment 1 of the present invention. Similar to the above-described hydrodesulfurizer integrated cylindrical steam reformer GHc, the hydrogen generator GH1 is configured such that the hydrodesulfurizer 103 is disposed below the carbon monoxide purifier 104 of the hydrogen generator main body 101, and A heat insulating material 107 is disposed on the outer periphery where the reformer 102 is located. In the present embodiment, the hydrogen generator GH1 is formed in a cylindrical shape, but is not limited to a cylindrical shape. The reformer 102 and the hydrodesulfurizer 103 may have any shape as long as they can effectively cause a reforming reaction, a carbon monoxide shift reaction, and a selective oxidation reaction. Examples of such a shape include a cylindrical shape, a rectangular tube shape, and a tubular shape. In addition, when incorporating in a fuel cell power generation device, a cylindrical shape is preferable.

  The carbon monoxide purifier 104 refers to at least one of the transformer 105 and the selective oxidizer 106. A CuZn (copper zinc) system is used as a catalyst for causing the carbon monoxide shift reaction, and the reaction is caused to occur at 150 to 350 ° C. A raw material gas obtained by mixing hydrogen generated by the reforming reaction in the reformer 102 and a hydrocarbon-based gas such as city gas, LP gas, and natural gas is hydrodesulfurized via the raw material gas supply path 108. After the sulfur compound is removed through the desulfurization catalyst filled in the vessel 103, the raw material gas discharge passage 110 is passed through and supplied to the reformer 102. The source gas supply path 108 is disposed in contact with or adjacent to the outer periphery of the transformer 105. Such a transformer 105 is provided in a hydrogen generator for supplying hydrogen to PEFC (solid polymer fuel cell) or SOFC (solid oxide fuel cell).

  FIG. 2 partially shows the appearance of the hydrogen generator GH1. A raw material gas supply passage 108 for supplying a raw material gas to the hydrodesulfurizer 103 is disposed along the side surfaces of the selective oxidizer 106 and the transformer 105, and in the vicinity of the lower end of the transformer 105, the circumferential direction of the side surface of the transformer 105. And is arranged so as to be in contact with or adjacent to the outer periphery of the transformer 105. A portion that contacts or is adjacent to the transformer 105 along the outer periphery of the transformer 105 is referred to as a heat exchange section Hex1 of the source gas supply path. The source gas supply path 108 and the heat exchange part Hex1 are arranged in contact with or adjacent to each other along the outer periphery of the transformer 105 so that heat exchange with the transformer 105 is possible. From the viewpoint of the heat exchange function, the raw material gas supply path 108 is an auxiliary one, and in order to stabilize the temperature of the raw material gas, the transformation heat exchange part Hex1 is essential.

  That is, since the raw material gas supply path 108 has a structural restriction that extends in the length direction of the carbon monoxide purifier 104 (transformer 105), the endothermic amount corresponding to the extended length (increased temperature of the raw material gas). Is difficult to control. On the other hand, since the heat exchanging section Hex1 extends (winds) in the circumferential direction of the transformer 105, the extension (winding) length control with respect to the endothermic amount (the rising temperature of the raw material gas) is (center). Easy). Therefore, in the present invention, the heat exchanging unit Hex1 is the main heat exchanging means, and the source gas supply path 108 is the auxiliary heat exchanging means. Specifically, since the raw material gas supply path 108 does not have a sufficient heat exchange area for sufficient heat exchange, the temperature cannot be controlled by itself, so that it can be easily used as an auxiliary heat exchange means. The heat exchange part Hex1 is used as the main heat exchange means.

  Let us consider a case where the source gas supply path 108 has sufficient endothermic (source gas temperature rising) capability. As described above, the source gas supply path 108 has a structural restriction that it extends in the length direction of the carbon monoxide purifier 104 (transformer 105), so that the amount of heat absorption is reduced in the source gas supply path 108 itself. I can't control it. Therefore, contrary to the intention, the source gas may be heated excessively. In this case, it is necessary to cool the overheated raw material gas, which not only requires unnecessary facilities and man-hours, but also wastes heat absorbed from the transformer 105 for heating the raw material gas. It is. That is, in the present invention, the heat absorption capacity of the raw material gas supply passage 108 having structural constraints is set smaller than the minimum required for heating the raw material gas to a desired temperature, and the insufficient heating capacity is set. It can be said that the raw material gas is stably heated by controlling the endothermic ability of the metamorphic heat exchange part Hex1 without structural constraints.

  The material gas supply path 108 and the transformer 105 and the heat exchanging unit Hex1 are in contact with or adjacent to each other so as to have a heat exchangeable configuration means that they are in thermal contact with or adjacent to each other. To do. Even if they are in physical contact or adjacent to each other, a thermal insulation material is sandwiched between them so that they are not thermally blocked. When adjacent to each other, it is preferable that the distance between the raw material gas supply path 108 and the transformer 105 and the heat exchange part Hex1 is 2 mm or less. Furthermore, the heat exchange part Hex1 of the source gas supply path 108 is preferably disposed so as to be wound around the outer periphery of the transformer 105 so that the predetermined center angle θ is an arc having a radius of about 300 ° or more. As described above, the central angle θ around which the heat exchanging unit Hex1 is wound along the outer periphery of the transformer 105 is referred to as a winding angle θ of the heat exchanging unit Hex1.

  The arrangement of the heat exchange part Hex1 in the raw material gas supply path 108 as described above is such that when the catalysts filled in the converter 105 and the hydrodesulfurizer 103 are of the same type such as CuZn, the control temperature is the converter. This is particularly effective because it is in the same region of 150 ° C. to 350 ° C. in each of 105 and hydrodesulfurizer 103. By sufficiently exchanging heat with the transformer 105 in the heat exchange section Hex1, the temperature of the raw material gas passed through the hydrodesulfurizer 103 can be brought close to the optimum temperature. Further, when the control temperature of the catalyst charged in the hydrodesulfurizer 103 is higher than the control temperature of the catalyst charged in the transformer 105, the raw material gas is supplied to the reformer 102 below the transformer 105. By bringing the heat exchange part Hex1 of the passage 108 into contact with or adjacent to each other, the temperature of the raw material gas supplied to the hydrodesulfurizer 103 can be set to an appropriate value.

  As described above, the raw material gas supply path 108 and the heat exchange part Hex1 of the raw material gas supply path 108 are arranged along the outer periphery of the carbon monoxide purifier 104 (transformer 105). By making the exchange part Hex1 heat exchangeable with the carbon monoxide purifier 104, the temperature of the hydrodesulfurization catalyst can be appropriately maintained to improve the reaction. That is, in this way, from the carbon monoxide purifier 104 (transformer 105) within the temperature range of 150 ° C. to 350 ° C., the raw material gas supply path 108 and the heat exchange unit Hex1 rise through heat exchange, that is, heat. Can be warmed. However, the temperature of the raw material gas supplied to the hydrodesulfurizer 103 is preferably 200 ° C. to 280 ° C. The source gas is further heated by the reforming reaction heat inside the hydrodesulfurizer 103. Considering these situations, the winding angle θ of the heat exchange unit Hex1 is determined so that the temperature of the raw material gas supplied to the hydrodesulfurizer 103 becomes a predetermined temperature (200 ° C. to 280 ° C.). .

(Embodiment 2)
FIG. 3 partially shows the appearance of the hydrogen generator according to Embodiment 2 of the present invention. The hydrogen generator main body 101b of the hydrogen generator GH2 has basically the same configuration as the hydrogen generator main body 101 according to the first embodiment. However, in the hydrogen generator main body 101, the source gas supply path 108 and the source gas discharge path 110 are separated from each other, but in the second embodiment, the source gas supply path 108 and the source gas discharge path 110 are in contact with each other. Or it is arranged in an adjacent position. Specifically, the source gas supply path 108 and the source gas discharge path 110 are in contact with or adjacent to each other on the same side (the left side in FIG. 3) of the carbon monoxide purifier 104. It is not something that can be done. Thus, in the present embodiment, the heat exchanging unit Hex2 absorbs heat (heat exchange) from the transformer 105 in the same manner as the heat exchanging unit Hex1 of the first embodiment, and the source gas supply path 108 is the same as that of the first embodiment. Unlike the above, the raw material gas discharge passage 110 is also configured to absorb heat (heat exchange).

  In the present embodiment, one of the purposes is to effectively use the heat of the source gas discharge passage 110. That is, the gas in the source gas discharge path 110 is at a high temperature (60 ° C. or higher) that is higher than the dew point of the discharged gas and does not condense. In order to effectively use the heat of the exhaust gas for the metamorphic reaction, it is intended to remove heat from the exhaust gas as much as possible (lower the temperature of the exhaust gas). From this point of view, the source gas supply path 108 is configured to be able to exchange heat with both the transformer 105 and the source gas discharge path 110.

  Specifically, the raw material gas passed through the raw material gas supply path 108 is removed from the sulfur compound via the hydrodesulfurizer 103 and then passed from the raw material gas discharge path 110 to the reformer 102. Sent to the route. The source gas discharged from the source gas discharge path 110 is heated to an optimum reaction control temperature. Particularly when a CuZn-based catalyst is used, the temperature is as high as about 150 ° C. to about 350 ° C. Therefore, if the raw material gas discharge path 110 is long, the amount of heat of the raw material gas flowing through the raw material gas discharge path 110 is removed by heat radiation to the outside air, and this amount of heat is converted to the raw material gas temperature supplied to the hydrodesulfurizer 103. Not enough for adjustment.

  In order to sufficiently use heat, it is necessary to supply the amount of heat of the raw material gas flowing through the raw material gas discharge passage 110 to the raw material gas supply passage 108 or the transformer 105. Similarly, the shorter the length of the source gas supply path 108, the less heat is released and the heat can be used efficiently. Therefore, as shown in FIG. 3, the temperature of the raw material gas flowing through the raw material gas supply passage 108 by performing heat exchange by bringing the raw material gas supply passage 108 and the raw material gas discharge passage 110 into contact with or adjacent to each other in the hydrogen generator GH 2. It is effective to raise As described above, in the present embodiment, one of the purposes is to remove the heat of the gas flowing in the source gas discharge path 110. That is, the temperature of the gas flowing through the transformer 105 is as high as 200 ° C. to 350 ° C., while the gas flowing through the source gas supply path 108 is a low temperature close to room temperature. Therefore, it is configured as described above in order to lower the temperature of the gas returned from the hydrodesulfurizer 103 to 60 ° C., which is higher than the dew point of the exhaust gas.

  If the flow rate of the source gas is about 15 NLM or less, it is preferable that the length in which the source gas supply path 108 and the source gas discharge path 110 are in contact with or adjacent to each other is 50 mm or more. When the source gas supply path 108 and the source gas discharge path 110 are adjacent to each other, the distance between the two is preferably within 2 mm. Thus, by arranging the source gas supply path 108 and the heat exchange part Hex2 of the source gas supply path 108 along the outer periphery of the carbon monoxide purifier 104, the source gas supply path 108 and the heat exchange part Hex2 are arranged. The structure can exchange heat with the carbon monoxide purifier 104, and further, the raw material gas supply passage 108 and the raw material gas discharge passage 110 are arranged in contact with each other or adjacent to each other, thereby maintaining the temperature of the hydrodesulfurization catalyst appropriately. Can be good.

  In the present embodiment, the source gas can be heated / heated up to 150 ° C. to 350 ° C. However, since the raw material gas in the raw material gas supply passage 108 is preheated by heat exchange with the raw material gas discharge passage 110 (temperature increase of about 50 ° C. to 100 ° C.), the heat exchange area with the transformer 105 is reduced, It is necessary to keep the temperature at the inlet of the hydrodesulfurizer 103 appropriately. For example, in the first embodiment, the winding angle θ wound around the transformer 105 is 300 ° C. or more, but it is appropriate to make it smaller than that.

(Embodiment 3)
FIG. 4 shows the internal structure of the hydrogen generator according to Embodiment 3 of the present invention. The hydrogen generator main body 101c of the hydrogen generator GH3 has basically the same configuration as the hydrogen generator main body 101 according to the first embodiment. However, in the hydrogen generator main body 101, the transformer 105 and the hydrodesulfurizer 103 are separated from each other, but in the third embodiment, a part of the hydrodesulfurizer 103c contacts the outer periphery of the transformer 105. Or it is arranged to be adjacent. If comprised in this way, the temperature of the hydrodesulfurizer 103c can be maintained appropriately, and the temperature of the hydrodesulfurization catalyst can be maintained appropriately by heat-exchanging the hydrodesulfurizer 103c and the converter 105.

  A portion of the hydrodesulfurizer 103c is disposed in contact with the outer periphery of the transformer 105, and a portion other than the portion of the hydrodesulfurizer 103c is in contact with the outer periphery where the reformer 102 is located via a heat insulating material 107c. Arranged. The raw material gas circulated in the raw material gas supply path 108 is preheated by the transformer 105 and then passed to the hydrodesulfurizer 103c. However, when starting up the hydrogen generator main body 101c or when the operating load fluctuates to change the amount of hydrogen generated, especially when the raw material gas flow rate is rapidly increased, the raw material gas supply is performed in order to sufficiently warm the raw material gas. The heat exchange between the hydrodesulfurizer 103c and the transformer 105 is exchanged by heat exchange between the passage 108 and the transformer 105 of the heat exchange part Hex1. Thereby, total heat exchange amount increases and it can maintain the temperature of the hydrodesulfurizer 103c more appropriately.

  In particular, when the catalyst sealed in the transformer 105 and the catalyst sealed in the hydrodesulfurizer 103c are similar catalysts such as a CuZn-based catalyst, it is more effective because the control temperature ranges are close to each other. As described above, by arranging the source gas supply path 108 and the heat exchange part Hex1 of the source gas supply path 108 along the outer periphery of the carbon monoxide purifier 104, the source gas supply path 108 and the heat exchange part are integrated. A structure capable of exchanging heat with the carbon oxide purifier 104 is arranged so that a part of the hydrodesulfurizer 103c is in contact with or adjacent to the outer periphery of the transformer 105, so that the temperature of the hydrodesulfurization catalyst is appropriately adjusted. The keeping reaction can be improved. In the present embodiment, heat can be absorbed from the carbon monoxide purifier 104 (transformer 105) operating at a reaction temperature of 150 ° C. to 350 ° C., and the temperature can be raised / heated within a range of 150 ° C. to 350 ° C. However, the temperature after the temperature rise is preferably 200 ° C to 280 ° C.

(Embodiment 4)
FIG. 5 partially shows the appearance of the hydrogen generator according to Embodiment 4 of the present invention. The hydrogen generator main body 101d of the hydrogen generator GH4 has basically the same configuration as the hydrogen generator main body 101 according to the first embodiment. However, in the fourth embodiment, the heat exchange unit Hex4 is disposed in contact with or adjacent to the outer periphery of the transformer 105 and the hydrodesulfurizer 103. If comprised in this way, the temperature of a hydrodesulfurization catalyst can be maintained appropriately by heat-exchanging the heat exchange part Hex4 with both the hydrodesulfurizer 103 and the converter 105. FIG.

  The hydrodesulfurizer 103 is disposed via a heat insulating material 107 below the carbon monoxide purifier 104 where the hydrogen generator main body 101d is located and on the outer periphery where the reformer 102 is located. A portion of the source gas supply path 108 that contacts or is adjacent to the transformer 105 and the hydrodesulfurizer 103 along the outer periphery of the transformer 105 is referred to as a heat exchange section Hex4 of the source gas supply path 108. The raw material gas supply path 108 is configured such that the heat exchanging unit Hex4 is brought into contact with or adjacent to the outer periphery of the transformer 105 and the hydrodesulfurizer 103 so that the transformer 105, the hydrodesulfurizer 103, and the raw gas supply path 108 are in contact with each other. And the heat exchanging unit Hex4 are arranged so as to be capable of exchanging heat.

  By exchanging heat with the hydrodesulfurizer 103 in the heat exchange part Hex4 of the raw material gas supply path 108, a part of the heat radiated from the hydrodesulfurizer 103 flows through the heat exchange part Hex4 of the raw material gas supply path 108. Can be returned to the raw material gas, and heat can be used effectively. Although heat radiation also occurs from the heat exchange part Hex4 of the raw material gas supply path 108, the heat radiation amount is because it is located on the upstream side of the raw material gas relative to the hydrodesulfurizer 103 and because it is at a lower temperature than the hydrodesulfurizer 103. It has the effect that the amount of heat radiation can be kept smaller.

  In this way, the raw material gas supply path 108 and the heat exchange part Hex4 can be heat exchanged along the outer periphery of the carbon monoxide purifier 104, and the heat exchange part Hex4 is further converted into the transformer 105 and the hydrodesulfurizer. By disposing it in contact with or adjacent to the outer periphery of 103, the temperature of the hydrodesulfurization catalyst can be appropriately maintained to improve the reaction. The endothermic (heat exchange) targets in the present embodiment are the carbon monoxide purifier 104 (transformer 105) and the hydrodesulfurizer 103, and the endothermic target temperatures are both 150 ° C. to 350 ° C. That is, by supplying the heat of the hydrodesulfurizer 103 to the raw material gas, the temperature of the raw material gas can be increased more than in the case of the carbon monoxide purifier 104 alone.

  The temperature rise of the raw material gas varies depending on how the heat exchange section Hex4 is wound, but preferably the temperature of the raw material gas entering the hydrodesulfurizer 103 is set to 200 ° C to 280 ° C. Further, since the heat of the hydrodesulfurizer 103 is returned to the raw material gas, the temperature rise of the hydrodesulfurizer 103 is less likely to rise than in the first and second embodiments, and a more appropriate temperature state can be maintained.

  Next, with reference to FIG.6 and FIG.7, the measurement result of the gas temperature which flows through an actual machine when an actual machine operation is performed is described. The actual machine operation refers to a state when an actual fuel cell system is operated using the configuration of the hydrogen generator GH1 according to the first embodiment described above. In FIG. 6, points A, B, C, D, E, F, and G respectively indicate locations where the temperature of the flowing gas is measured, that is, measurement points in the actual machine. Specifically, measurement points A and B are points at both ends of the source gas supply path. Measurement points C, D, and E are points separated from the source gas supply path side end to the other end side at a predetermined interval in the catalyst of the hydrodesulfurizer. Measurement points F and G are points on both end sides inside the catalyst of the transformer.

  The actual machine test conditions were as follows: city gas as raw material gas at a flow rate of 2.96 NLM, water at 7.8 cc / min, combustion air at 18.3 NLM, and S / C (water vapor to carbon ratio). ) Is 2.8, and the control temperature of the reforming catalyst is 630 ° C. The hydrogen-containing gas produced by the reformer mixed with the raw material gas was set to 300 CCM. The inflow temperature of the raw material gas was set to 22 ° C., which is normal temperature. As the catalyst, the shift catalyst and the hydrodesulfurization catalyst are CuZn-based, and the control temperature of each catalyst is 150 ° C. to 300 ° C.

  FIG. 7 shows the measured gas temperature for each measurement. In FIG. 7A, points Ta and Tb indicate measurement temperatures at measurement points A and B at both ends of the source gas supply path. A line L1 represents a temperature gradient between the measurement point A and the measurement point B. Specifically, the gas temperature Ta at the measurement point A was 22 ° C., and the gas temperature Tb at the measurement point B was 237 ° C.

  In FIG. 7B, points Tc, Td, and Te respectively indicate the temperatures of the measurement points C, D, and E in the hydrodesulfurization catalyst, that is, the catalyst temperature. Line L2 represents the temperature gradient between measurement points C, D, and E. Specifically, the catalyst temperature Tc at the measurement point A was 207 ° C., the catalyst temperature Td at the measurement point D was 235 ° C., and the catalyst temperature Te at the measurement point E was 274 ° C.

  In FIG. 7C, points Tf and Tg indicate the temperatures of the measurement points F and G in the catalyst of the transformer, that is, the catalyst temperature, respectively. A line L3 represents a temperature gradient between the measurement point Tf and the measurement point Tg. Specifically, the catalyst temperature Tf at the measurement point F was 258 ° C., and the catalyst temperature Tg at the measurement point G was 178 ° C.

  The following facts are confirmed from the measurement results. That is, the raw material gas introduced at room temperature is heat-exchanged at a temperature point of 258 ° C. at the measurement point F upstream of the transformer while flowing through the raw material gas supply path, and the measurement point from 22 ° C. (Ta). When the temperature reaches B, the temperature is raised to 237 ° C. (Tb). And it falls to 207 ° C. (Tc) at the measurement point C at the hydrodesulfurizer inlet, but it is raised to 274 ° C. (Te) at the measurement point E at the outlet after passing through 235 ° C. (Td) at the middle measurement point D. The The fact that 207 ° C. (Tc) at measurement point C at the hydrodesulfurizer inlet is 30 ° C. lower than 237 ° C. (Tb) at measurement point B is considered to be due to heat dissipation. However, it can be seen that the configuration of the present invention satisfies the specified temperature of the catalyst from the inlet side of the hydrodesulfurizer. From this, it can be seen that the present invention is effective.

  As described above, each part of the hydrogen generators GH1 to GH4 (generally referred to as a hydrogen generator GH as necessary) is operated in a predetermined temperature range. Specifically, the reformer 102 is 600 ° C to 700 ° C, the carbon monoxide purifier 104 (transformer 105) is 80 ° C to 200 ° C, and the hydrodesulfurizer 103 is 200 ° C to 400 ° C. That is, each part can be at an arbitrary temperature within a predetermined temperature range. Therefore, depending on the temperature of each part, the raw material gas cannot be the same as the temperature at the entrance of the hydrodesulfurizer 103.

  More specifically, if the heat absorption target of the heat exchange unit Hex or the source gas supply path 108 is higher than the desired temperature of the source gas, the heat exchange unit Hex or the source gas supply path 108 is devised (for example, the heat exchange unit Hex By limiting the endothermic amount by adjusting the winding angle θ, etc., it is possible to prevent the source gas from being heated more than necessary and to achieve a preferable temperature. In this case, there is no temperature difference between the source gas and the inside of the hydrodesulfurizer 103, that is, there is an effect that the reforming can be performed at a uniform temperature.

  However, when the endothermic temperature is higher than the desired temperature of the source gas, the source gas cannot be heated to a preferred temperature. In this case, although there is a temperature difference between the raw material gas and the inside of the hydrodesulfurizer 103, the difference from the internal temperature of the hydrodesulfurizer 103 is reduced by 55 ° C. as compared with the difference in the prior art. By relaxing the temperature difference as described above, the collapse of the soaking zone inside the hydrodesulfurizer 103 is also alleviated, and the portion is prevented from being excessively cooled. As a result, it is possible to prevent the desulfurization reaction in the hydrodesulfurizer 103 from being damaged, or in the worst case, the hydrodesulfurizer 103 can be prevented from being damaged by thermal shock.

  In the above-described actual machine operation, the distance between the measurement point A and the measurement point B in FIG. 6 is 200 mm, and the source gas discharge path 110 and the source gas supply path 108 are installed with an interval of 2 mm. The winding angle θ of the heat exchange part Hex2 is 300 ° and the radius is 140 mm. The transformer 105 and the heat exchange part Hex2 are also installed with an interval of 2 mm. As a result, even when a source gas of 22 ° C. is supplied to the source gas supply path 108, the temperature is 207 ° C. at the inlet of the hydrodesulfurizer 103. In the conventional hydrogen generator, the raw material gas at 22 ° C. becomes 22 ° C. or very close to the temperature at the transformer 105.

  The hydrogen generator provided with the hydrodesulfurizer according to the present invention can be applied to a fuel cell system including a hydrogen generator and a fuel cell that generates power using a hydrogen-containing gas supplied from the hydrogen generator.

  The hydrogen generator equipped with the hydrodesulfurizer according to the present invention can be used for a hydrogen generator that supplies hydrogen to PEFC (solid polymer fuel cell) or SOFC (solid oxide fuel cell).

GHc, GH1, GH2, GH3, GH4 Hydrogen generator Hex1, Hex2, Hex4 Heat exchanger 101, 101b, 101c, 101d Hydrogen generator body 102 Reformer 103, 103c Hydrodesulfurizer 104 Carbon monoxide purifier 105 Metamorphic Unit 106 Selective oxidizer 107, 107c Heat insulating material 108 Source gas supply path 109 Source gas inlet header 110 Source gas discharge path 201 Hydrogen generator main body 202 Transformer 203 Reformer 204 Hydrodesulfurization catalyst 205 Outer cylinder 206 Inner cylinder 207 Top Face plate 208 Bottom plate 209 Partition plate 210 Upper header 211 Lower header 212 Source gas discharge pipe 213 Source gas supply pipe

Claims (5)

A cylindrical reformer that generates a hydrogen-containing gas by a reforming reaction using a raw material gas;
A cylindrical carbon monoxide purifier that reduces carbon monoxide in the hydrogen-containing gas produced by the reformer;
A cylindrical hydrodesulfurizer that is provided on the outer periphery of the reformer and removes sulfur compounds in the raw material gas;
A source gas supply path through which source gas supplied to the hydrodesulfurizer flows,
The raw material gas supply path is arranged so as to be capable of exchanging heat along the outer peripheral surface of the carbon monoxide purifier, and the first heat exchange extending parallel to the central axis of the carbon monoxide purifier And a second heat exchanging portion extending for a length defined by a predetermined central angle in the outer circumferential direction . 2. The hydrogen generation apparatus according to claim 1 , wherein the second heat exchange section extends across the carbon monoxide purifier and the hydrodesulfurizer. A raw material gas discharge passage through which the raw material gas discharged from the hydrodesulfurizer flows;
The raw material gas discharge passage, the hydrogen generating apparatus according to claim 1, characterized in that it is the first heat exchanging portion and the heat exchangeably disposed. The hydrogen generation apparatus according to any one of claims 1 to 3 , wherein the hydrodesulfurizer is provided on an outer periphery of the carbon monoxide purifier. A fuel cell system comprising: the hydrogen generator according to any one of claims 1 to 4 ; and a fuel cell that generates electric power using a hydrogen-containing gas supplied from the hydrogen generator.