JP2009091187A - Hydrogen producing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen producing apparatus capable of improving the removal efficiency of carbon monoxide by enhancing the reaction efficiency of a catalytic reaction for removing carbon monoxide. <P>SOLUTION: The hydrogen producing apparatus is provided with a CO removing part 15 for removing carbon monoxide contained in a reformed gas from a reformer 13, a lower part channel S4 for cooling the CO removing part 15 by reforming water introduced into the reformer 13 for steam reforming, thermocouples 61, 62 provided in the CO removing part 15 and a reforming water control part 65 for controlling the flow rate of reforming water W flowing a cooling line S4 based on the temperature detected by the thermocouples 61, 62. The carbon monoxide removing efficiency is improved by controlling the flow rate of the reforming water based on the temperature detected by the thermocouples 61, 62 to easily keep the CO removing part 15 at the optimum temperature. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hydrogen production apparatus that generates a hydrogen-rich reformed gas.

Patent Document 1 discloses a hydrogen production apparatus that generates a reformed gas by steam reforming a raw material for hydrogen production such as kerosene or gasoline, and supplies the produced reformed gas to a fuel cell stack. This type of hydrogen production apparatus includes a reformer that houses a reforming catalyst. Fuel gas and water vapor are introduced into the reformer. The reforming catalyst in the reformer is heated to a predetermined temperature by a burner or the like. The steam reforming of the fuel gas and steam is promoted by the reforming catalyst heated to a predetermined temperature. The reformed gas produced by the reformer contains carbon monoxide that reduces power generation efficiency due to poisoning. Therefore, the hydrogen production apparatus is provided with a converter that reduces carbon monoxide by an aqueous shift reaction and a selective oxidizer that further reduces carbon monoxide by a selective oxidation reaction. The aqueous shift reaction and the selective oxidation reaction are exothermic reactions, and the reaction efficiency decreases when the transformer or the selective oxidizer becomes too high in temperature. Therefore, the transformer and the selective oxidizer are appropriately cooled with cooling water.
JP 2004-175621 A

  However, in the conventional hydrogen production apparatus, the control for maintaining the transformer and the selective oxidizer at an optimum temperature is insufficient, and the reaction efficiency of the catalytic reaction such as the aqueous shift reaction and the selective oxidation reaction tends to be reduced. There was a risk that the removal of carbon oxide would be insufficient.

  An object of the present invention is to solve the above problems, and to provide a hydrogen production apparatus capable of improving the reaction efficiency of a catalytic reaction for removing carbon monoxide and improving the removal efficiency of carbon monoxide. With the goal.

  A hydrogen production apparatus according to the present invention includes a reforming unit that reforms a raw material for hydrogen production to generate a hydrogen-rich reformed gas, and an aqueous shift reaction of carbon monoxide contained in the reformed gas from the reforming unit. The shift unit removed by the step, the selective oxidation unit that selectively oxidizes carbon monoxide contained in the reformed gas from the shift unit, and the shift unit and the selective oxidation unit by the reforming water introduced into the reforming unit for reforming Detected by a cooling line for cooling the first sensor unit, a first sensor unit for detecting the temperature of the shift unit, a second sensor unit for detecting the temperature of the selective oxidation unit, and the first sensor unit and the second sensor unit. And a control unit for controlling the flow rate of the reforming water flowing in the cooling line based on the temperature.

  In this hydrogen production apparatus, the shift unit and the selective oxidation unit can be cooled by the reforming water flowing in the cooling line, and the reforming water heated by heat exchange with the shift unit and the selective oxidation unit can be introduced into the reforming unit. Efficient. Further, the control unit monitors the temperatures of the shift unit and the selective oxidation unit via the temperatures detected by the first sensor unit and the second sensor unit, and based on this temperature, the flow rate of the reforming water Therefore, it is easy to maintain the shift unit and the selective oxidation unit at an optimum temperature. As a result, the efficiency of removing carbon monoxide can be improved by improving the reaction efficiency of the aqueous shift reaction and the selective oxidation reaction.

  Furthermore, the supply amount of the raw material for hydrogen production supplied to the reforming unit is determined according to the desired generation amount of the reformed gas, and the reference supply amount of reforming water supplied to the reforming unit is the hydrogen production The control unit determines whether the temperature detected by the first sensor unit is equal to or higher than the first threshold value, or the temperature detected by the second sensor unit is the second threshold value. In the above case, it is preferable to control the flow rate of the reforming water so that an excessive amount of the reforming water is supplied in addition to the reference supply amount of the reforming water. The surplus reforming water passes without reacting in the reforming section, so there is little influence on the reaction in the reforming section, and the standard supply amount of reforming water can be stably maintained. The shift portion and the selective oxidation portion can be effectively cooled without reducing the production efficiency of the quality gas.

  Further, the shift unit includes a high-temperature shift unit and a low-temperature shift unit that is suitable for an aqueous shift reaction at a lower temperature than the high-temperature shift unit, and is disposed downstream of the reformed gas flow from the high-temperature shift unit. The first sensor unit is preferably arranged at the inlet of the low temperature shift unit. The reformed gas from the reforming section is introduced into the shift section at a high temperature, and the temperature gradually decreases while passing through the shift section. Therefore, the aqueous shift reaction can be efficiently performed by disposing the high temperature shift portion on the upstream side of the reformed gas flow and disposing the low temperature shift portion on the downstream side. Furthermore, in the low temperature shift part, the temperature of the inlet becomes the highest, and by arranging the first sensor part at the inlet of the low temperature shift part, the temperature of the entire low temperature shift part can be easily maintained at an optimum temperature. As a result, the reaction efficiency of the aqueous shift reaction in the low temperature shift part can be improved.

  Further, the cooling line includes a first line connected to the selective oxidation unit so as to be capable of transferring heat, and a second line connected to the shift unit so as to be able to transfer heat, wherein the first line includes: It is preferable that it is arranged on the upstream side of the flow of reforming water with respect to the second line. The reforming water flowing in the first line is mainly heat-exchanged with the selective oxidation unit, and a part of the reforming water is converted into water vapor and introduced into the second line. Therefore, variation in temperature distribution in the shift portion is suppressed as compared with the case where the shift portion is rapidly cooled only with low-temperature water.

  Furthermore, a water temperature detection sensor provided in the cooling line is provided, and the control unit cools based on the temperature detected by the water temperature detection sensor in addition to the temperature detected by the first sensor unit and the second sensor unit. It is preferable to control the flow rate of the reforming water flowing in the line. The temperature of the reforming water flowing through the cooling line can be monitored by the water temperature detection sensor. And since a control part controls the flow volume of reforming water based on the temperature of reforming water, it can suppress more reliably the temperature rise of a shift part or a selective oxidation part. As a result, the removal efficiency of carbon monoxide can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the reaction efficiency for removing carbon monoxide can be improved, and the removal efficiency of carbon monoxide can be improved.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

  FIG. 1 is a diagram showing an outline of a fuel cell system to which a hydrogen production apparatus according to the present invention is applied. The fuel cell system 1 generates power using a liquid raw material as a raw material for hydrogen production, and is employed as, for example, a household power supply source. Here, kerosene is used as the liquid raw material from the viewpoint that it is easily available and can be stored independently.

  As shown in FIG. 1, a fuel cell system 1 includes a desulfurizer 2, a hydrogen production apparatus (hereinafter referred to as “FPS”) 3A according to the first embodiment, a solid polymer fuel cell (hereinafter referred to as “PEFC”). ) A stack 4, an inverter 5, and a housing 6 for housing them are provided.

  The desulfurizer 2 desulfurizes a liquid raw material introduced from the outside. The desulfurizer 2 is provided with a heater (not shown), whereby the desulfurizer 2 is heated to, for example, 130 ° C. to 140 ° C.

  The FPS 3A is disposed so as to surround the combustion cylinder 11 including a burner 9 as a heat source (see FIG. 2), and a reformer that generates a hydrogen-rich reformed gas by steam reforming the liquid material. (Reforming section) 13, a transformer 41 for removing carbon monoxide in the reformed gas flowing out from the reformer 13, and a selective oxidizer 44 are provided. The transformer 41 is arranged on the upstream side, the selective oxidizer 44 is arranged on the downstream side, and the CO removing unit 15 is configured by the transformer 41 and the selective oxidizer 44.

  As shown in FIG. 2, the reformer 13 includes a cylindrical inner trunk portion 17 disposed concentrically with the combustion cylinder 11 outside the combustion cylinder 11, and an inner trunk section outside the inner trunk section 17. 17 and a cylindrical outer body portion 19 arranged concentrically with each other. In the upper portion of the inner body portion 17 and the outer body portion 19, the raw material gas vaporized from the liquid raw material and the reforming water vaporized are introduced. An introduction part 21 is provided. An exhaust gas flow path S1 in which the exhaust gas G2 from the combustion cylinder 11 rises is formed between the combustion cylinder 11 and the inner trunk portion 17. The exhaust gas G2 has the highest temperature in the vicinity of the lower portion of the inner trunk portion 17, and is heat-exchanged with the reformer 13 and gradually cooled when ascending the exhaust gas passage S1.

  A reduced diameter cylindrical portion 19 a having a diameter smaller than that of the upper portion is formed at the lower portion of the outer body portion 19. A reforming catalyst C1 that promotes a steam reforming reaction between the raw material gas and the steam to generate the reformed gas G1 is accommodated between the inner barrel portion 17 and the outer barrel portion 19. An annular perforated plate 19b that supports the reforming catalyst C1 is provided at the lower end. The reforming catalyst C1 is a noble metal steam reforming catalyst and uses ruthenium. The temperature suitable for the catalytic reaction of the reforming catalyst C1 is 550 ° C to 800 ° C.

  The reformed gas G1 generated in the reformer 13 passes through the perforated plate 19b and flows downward. A reformed gas outflow portion 23 is formed by the reduced diameter cylindrical portion 19a, the lower cylindrical portion 17a of the inner cylindrical portion 17 facing the reduced diameter cylindrical portion 19a, and the perforated plate 19b.

  A cylindrical partition wall 27 is disposed outside the reduced diameter cylindrical portion 19 a of the outflow portion 23. The partition wall 27 is fixed to the edge of a circular guide plate 28 disposed below the outflow portion 23, and the guide plate 28 is fixed to the lower end of the inner trunk portion 17. A cylindrical heat transfer wall portion 29 is disposed outside the partition wall 27, and the heat transfer wall portion 29 is fixed to the outer body portion 19 of the reformer 13.

  By the guide plate 28 and the partition wall 27, a detour S2 of the reformed gas G1 is formed. That is, the reformed gas G1 flowing out from the outflow portion 23 collides with the guide plate 28, changes its flowing direction, and rises along the outer peripheral surface 19c of the reduced diameter cylindrical portion 19a while being guided by the partition wall 27. Thereafter, the reformed gas G1 returns through the upper end of the partition wall 27 and descends along the inner peripheral surface 29a of the heat transfer wall portion 29. When the reformed gas G1 flowing in the detour S2 rises along the partition wall 27, the reformed gas G1 exchanges heat with the reforming catalyst C1 via the outer body portion 19 to prevent the temperature of the reforming catalyst C1 from decreasing.

  A cylindrical upper water channel wall 35 disposed concentrically with the heat transfer wall 29 is provided outside the heat transfer wall 29. Between the heat transfer wall portion 29 and the upper water channel wall 35, an upper water channel S3 is formed in which reforming water for steam reforming flows. The upper water channel S3 is connected to the reformer 13 via the heat transfer wall 29 so as to be capable of heat exchange (heat transfer). The reforming water W rises in the upper water channel S3, is heated by the heat of the burner 9 through the reformer 13, and is supplied to the introduction portion 21 of the reformer 13 as high-temperature steam. The reformed gas G1 flowing out of the reformer 13 and flowing through the bypass S2 is heat-exchanged with the reforming water W via the heat transfer wall 29 and cooled.

  The FPS 3 </ b> A is disposed adjacent to the lower side of the reformer 13 and includes a CO removing unit 15 that removes carbon monoxide contained in the reformed gas G <b> 1 from the reformer 13. The CO removing unit 15 includes a transformer (shift unit) 41 that reduces carbon monoxide from the reformed gas G1 by an aqueous shift reaction, and a mixing chamber 42 that mixes the reformed gas G1 from the transformer 41 and the oxygen-containing gas. A cooling chamber section 43 that cools the reformed gas G1 (mixed gas) from the mixing chamber 42, and a selection that selectively oxidizes carbon monoxide in the reformed gas G1 (mixed gas) cooled in the cooling chamber section 43. An oxidizer (selective oxidation unit) 44 is provided. The CO removal unit 15 will be described in more detail.

  The CO removal unit 15 is a substantially cylindrical first region A1, an outer periphery of the first region A1, a second region A2 that is an annular region concentric with the first region A1, and an outer periphery of the second region A2. 3rd area | region A3 which is located in the side and is a cyclic | annular area | region concentric with 1st area | region A1 is provided. The third region A3 is surrounded by a bottomed cylindrical heat transfer cylinder 54.

  The reformed gas G1 from the reformer 13 first descends through the second region A2, and then ascends the inner first region A1. A communication channel R that connects the first region A1 and the third region A3 so as to straddle the second region A2 is formed above the first region A1, and reaches the upper portion of the first region A1. The reformed gas G1 reaches the third region A3 through the communication channel R. Thereafter, the reformed gas G1 descends in the third region A3. Hereinafter, the second region A2, the first region A1, and the third region A3 will be described in the order along the flow of the reformed gas G1.

  In the second region A2, an annular high temperature shift section 47 is disposed on the upstream side when the flow of the reformed gas G1 is used as a reference, and an annular low temperature shift section 49 is disposed on the downstream side. The reformed gas G1 from the reformer 13 is in a very high temperature state of 600 ° C. or higher, and the high temperature shift section 47 has a high temperature shift catalyst (“HTS”) advantageous for promoting an aqueous shift reaction at a high temperature. C2) is also housed. As the high temperature shift catalyst C2, a mixed oxide of Fe—Cr is used. A suitable temperature for the catalytic reaction of the high temperature shift catalyst C2 is 300 ° C to 500 ° C.

  The low temperature shift portion 49 accommodates a low temperature shift catalyst (also referred to as “LTS”) C3 suitable for promoting the aqueous shift reaction at a temperature lower than that of the first shift catalyst. As the low temperature shift catalyst C3, a mixed oxide of Zn—Cu is used. A suitable temperature for the catalytic reaction of the low temperature shift catalyst C3 is about 200 ° C.

  The high temperature shift unit 47 and the low temperature shift unit 49 constitute a transformer 41. By the aqueous shift reaction by the transformer 41, the concentration of carbon monoxide contained in the reformed gas G1 is reduced to about 1%. In particular, the reformed gas G1 from the reformer 13 is introduced into the transformer 41 at a high temperature, and the temperature gradually decreases in the process of passing through the transformer 41. Therefore, the aqueous shift reaction can be efficiently performed by disposing the high temperature shift unit 47 on the upstream side of the flow of the reformed gas G1 and disposing the low temperature shift unit 49 on the downstream side.

  The reformed gas G1 that has flowed downward from the transformer 41 flows into the inner first region A1. The first region A1 is provided with a central flow path 51 through which the reformed gas G1 rises and a mixing chamber 42 connected to the upper end of the central flow path 51. The mixing chamber 42 mixes the reformed gas G1 and the oxygen-containing gas. The mixing chamber 42 is connected to a connecting pipe 52 that passes through the high temperature shift portion 47 in the second area A2, and the connecting pipe 52 has a connecting flow path R that connects the first area A1 and the third area A3. Is formed.

  In the third region A3, an annular cooling chamber portion 43 connected to the communication pipe 52 and an annular selective oxidizer 44 disposed below the cooling chamber portion 43 are provided. The selective oxidizer 44 accommodates a selective oxidation catalyst C4 that promotes a selective oxidation reaction. As the selective oxidation catalyst C4, a catalyst containing iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, silver, gold or the like is used. A suitable temperature for the catalytic reaction of the selective oxidation catalyst C4 is 150 ° C to 160 ° C. In the selective oxidizer 44, the carbon monoxide concentration in the reformed gas G1 (mixed gas) is reduced to 10 ppm or less. A reformed gas outflow portion 53 through which the reformed gas G1 after the reduction of carbon monoxide flows out is provided below the selective oxidizer 44. The reformed gas outlet 53 is connected to a reformed gas supply line L3 (see FIG. 1) that communicates with the PEFC stack 4.

  The CO removing unit 15 has a cylindrical heat transfer tube 54 surrounding the third region A3, and a cylindrical lower channel wall 55 concentric with the heat transfer tube 54 is disposed outside the heat transfer tube 54. Yes. A lower water channel (cooling line) S4 through which the reforming water W used for steam reforming flows is formed between the heat transfer cylinder 54 and the lower water channel wall 55. The lower water channel S4 includes a first line S4a connected to the selective oxidizer 44 so as to be able to transfer heat, and a second line S4b connected to the high temperature shift unit 47 via the cooling chamber 43 so as to be able to transfer heat. Have. When the flow of the reforming water W is used as a reference, the first line S4a is disposed on the upstream side, and the second line S4b is disposed on the downstream side. A reforming water introduction part 55a is provided below the second line S4b.

  The reforming water introduced into the reforming water introduction unit 55a at room temperature is heat-exchanged with the selective oxidizer 44 when flowing through the first line S4a (see FIG. 4). Although the selective oxidizer 44 generates an exothermic reaction, the selective oxidizer 44 is maintained at a suitable temperature by being cooled by the reforming water W. On the other hand, the reforming water W flowing through the first line S4a is partially heated by being heated by the selective oxidizer 44 and flows into the second line S4b.

  An exothermic reaction also occurs in the transformer 41. The high temperature shift portion 47 of the transformer 41 is heat-exchanged with the reforming water W flowing through the second line S4b, and is maintained at a suitable temperature. A part of the reforming water W that has flowed into the second line S4b from the first line S4a is steam. Therefore, variation in temperature distribution in the high temperature shift portion 47 is suppressed as compared with the case where the high temperature shift portion 47 is rapidly cooled only by low temperature water. The low temperature shift section 49 is indirectly cooled with the reforming water W via the selective oxidizer 44 and maintained at a suitable temperature.

  The lower water channel S4 is connected to the upper water channel S3 disposed on the downstream side via the communication water channel S5. The communication channel S5 is in contact with the reformed gas communication channel S6 that communicates between the reformer 13 and the CO removing unit 15 so as to allow heat exchange. The reformed gas G1 flowing down the reformed gas communication path S6 is 600 ° C. or higher. The reforming water flowing through the communication channel S5 cools the reformed gas G1 to a temperature suitable for the high temperature shift catalyst C2 of the high temperature shift unit 47. The reforming water W that has passed through the communication channel S5 is further heated in the upper channel S3, and is introduced into the introduction part 21 of the reformer 13 in a high temperature state.

  Since the reforming water W is heated by the CO removing unit 15 and the reformer 13 and is introduced into the introduction unit 21 of the reformer 13 as high-temperature steam, another heat source for heating the reforming water W, For example, a heater is unnecessary. Furthermore, since the CO removal unit 15 can be cooled by the reforming water W flowing through the lower water channel S4, other means for cooling the CO removal unit 15 are unnecessary, and energy efficiency is high.

  A reforming water supply line L21 is connected to the lower water channel S4 via a reforming water introduction section 55a, and a water tank 20 (see FIG. 1) is connected to the reforming water supply line L21. A reforming water replenishment line L22 is connected to. A transfer pump 43 for feeding the reforming water W to the reformer 13 is provided on the reforming water supply line L21.

  The transformer 41 is provided with a first thermocouple (first sensor unit) 61 for detecting the temperature. The selective oxidizer 44 is provided with a second thermocouple (second sensor unit) 62 for detecting the temperature. The lower water channel S4 is provided with a third thermocouple (water temperature detection sensor) 63 for detecting the temperature. The first thermocouple 61, the second thermocouple 62, and the third thermocouple 63 are connected to the reforming water control unit (control unit) 65 so that an electric signal can be input. The reforming water control unit 65 is connected to a transfer pump 43 that is a reforming water supply means so as to be able to transmit and receive signals, and drives and controls the transfer pump 43.

  The reforming water control unit 65 controls the flow rate of the reforming water W by the transfer pump 43 based on the temperatures detected by the first thermocouple 61, the second thermocouple 62, and the third thermocouple 63, and transforms them. The temperature of the vessel 41 and the selective oxidizer 44 is controlled to be a temperature suitable for each catalytic reaction. As a result, the removal efficiency of carbon monoxide can be improved by improving the reaction efficiency of the catalytic reaction that promotes the removal of carbon monoxide.

  In particular, the reforming water control unit 65 can monitor the temperature of the transformer 41 by the first thermocouple 61 and can monitor the temperature of the selective oxidizer 44 by the second thermocouple 62. It is easy to maintain the vessel 44 at an optimum temperature. As a result, the efficiency of removing carbon monoxide can be improved by improving the reaction efficiency of the aqueous shift reaction and the selective oxidation reaction.

  Further, as shown in FIG. 2, the first thermocouple 61 is disposed at the inlet of the low temperature shift unit 49. Since the temperature of the low temperature shift unit 49 is highest at the entrance, the temperature of the entire low temperature shift unit 49 can be easily maintained at an optimal temperature lower than that of the high temperature shift unit 47. As a result, the reaction efficiency of the aqueous shift reaction in the low temperature shift part 49 can be improved, and the removal efficiency of carbon monoxide can be improved. The second thermocouple 62 is disposed at the inlet of the selective oxidizer 44. The temperature of the selective oxidizer 44 is highest at the inlet of the selective oxidizer 44. By disposing the second thermocouple 62 at the inlet of the selective oxidizer 44, the reaction efficiency of the selective oxidation reaction in the selective oxidizer 44 can be improved, and the removal efficiency of carbon monoxide can be improved.

  Further, the temperature of the reforming water flowing through the lower water channel S4 can be monitored by the third thermocouple 63. Therefore, the reforming water control unit 65 can control the flow rate of the reforming water W based on the temperature of the reforming water W, and can more reliably suppress the temperature rise of the transformer 41 and the selective oxidizer 44. As a result, the removal efficiency of carbon monoxide can be improved. In particular, the third thermocouple 63 is disposed in the second line S4b of the lower water channel S4, and the temperature of the reforming water W after being heated by the selective oxidizer 44 can be monitored. As a result, it can be accurately monitored whether the cooling effect on the selective oxidizer 44 is sufficient, the reaction efficiency of selective oxidation can be improved, and the removal efficiency of carbon monoxide can be improved.

  As shown in FIG. 1, the PEFC stack 4 is configured by stacking a plurality of battery cells (not shown), and generates power using the reformed gas G1 obtained by the FPS 3A and outputs a DC current. . The battery cell has an anode, a cathode, and a polymer ion exchange membrane that is an electrolyte disposed between the anode and the cathode. The reformed gas G1 is introduced into the anode and air is introduced into the cathode. By doing so, an electrochemical power generation reaction is performed in each battery cell.

  The inverter 5 converts the output DC current into AC current. The housing 6 accommodates the desulfurizer 2, the FPS 3A, the PEFC stack 4, and the inverter 5 in a module.

  The fuel cell system 1 also includes a liquid source line L1 for introducing the liquid source from the outside of the housing 6 into the FPS 3A. A desulfurizer 2 is provided on the liquid raw material line L1. The downstream side of the liquid raw material line L1 from the desulfurizer 2 is branched, one is a liquid raw material line L11 for introducing the liquid raw material into the reformer 13, and the other is the liquid raw material for supplying the liquid raw material to the burner 9. It is line L12.

  Next, the flow control of the reforming water for cooling the CO removing unit 15 will be described with reference to FIG. FIG. 3 is a flowchart showing an operation procedure for controlling the flow rate of reforming water. In FIG. 3, step is abbreviated as S.

  The reforming water control unit 65 includes the temperature Ts of the transformer 41 detected by the first thermocouple 61, the temperature Tp of the selective oxidizer 44 detected by the second thermocouple 62, and the third thermocouple 63. Each of the detected temperatures Tw of the reforming water W is acquired (step S1).

The reforming water control unit 65 determines whether or not the temperature Tw of the reforming water W is lower than a predetermined threshold (third threshold) T _W0 (step S2), and the temperature Tp of the selective oxidizer 44 is a predetermined threshold ( It is determined whether or not (second threshold value) T _P0 or less (step S3), and whether or not the temperature Ts of the transformer 41 is lower than a predetermined threshold value (first threshold value) T _S0 (step S4). all temperature Tw, Tp, if Ts is less than the threshold value _{T W0, T P0, T S0} respectively, each temperature Tw returns to step S1, Tp, acquires Ts again.

On the other hand, the reforming water control unit 65 controls the drive of the transfer pump 43 when any one of the temperatures Tw, Tp, and Ts is _{equal to} or higher than the threshold values T _W0 , T _P0 , and T _S0. reforming water W flow by e.g. P% in addition to the standard supply quantity of surplus water W is to be supplied to the reformer 13, the state is maintained T ₁ seconds only (step S5). The reference supply amount of the reforming water W is determined according to the supply amount of the liquid raw material, and the supply amount of the liquid raw material is determined according to the desired generation amount of the reformed gas G1 in the FPS 3A. After the elapse of T ₁ second, the reforming water control unit 65 controls the drive of the transfer pump 43, returns the flow rate of the reforming water W to the specified amount, and maintains that state for T ₂ seconds (step S6). Thereafter, the process returns to step S1 to acquire each temperature Ts, Tp, Tw and repeatedly execute each subsequent process.

  According to the above FPS 3A, the reformer 41 and the selective oxidizer 44 are cooled by the reforming water W flowing through the lower water channel S4, and the reforming water W heated by heat exchange with the transformer 41 and the selective oxidizer 44 is used. Since it can be introduced into the reformer 13, it is efficient. Further, the reforming water control unit 65 monitors the temperatures of the transformer 41 and the selective oxidizer 44 via the temperatures Ts and Tp detected by the first thermocouple 61 and the second thermocouple 62, Since the flow rate of the reforming water W is controlled based on the temperatures Ts and Tp, it is easy to maintain the transformer 41 and the selective oxidizer 44 at optimum temperatures. As a result, the reaction efficiency of the catalytic reaction for removing carbon monoxide can be improved, and the removal efficiency of carbon monoxide can be improved.

Furthermore, in the present embodiment, when any one of the temperatures Tw, Tp, Ts is equal to or higher than the threshold values T _W0 , T _P0 , T _S0 , the flow rate of the reforming water W is added to the reference supply amount, for example, P The CO removal unit 15 is cooled such that the surplus reforming water W by% is supplied to the reformer 13. Since this surplus reforming water W passes through the reformer 13 without reacting, there is little influence on the reaction in the reformer 13, and the reference supply amount of the reforming water W is stabilized. Since it can maintain, the CO removal part 15 can be cooled efficiently.

(Second Embodiment)
Next, a hydrogen production apparatus (FPS) 3B according to the second embodiment will be described with reference to FIG. The FPS 3B differs from the FPS 3A according to the first embodiment in the arrangement of the first thermocouple (first sensor unit) 71 and the second thermocouple (second sensor unit) 72. Accordingly, the FPS 3B will be described with a focus on differences from the FPS 3A, and the same elements and structures will be denoted by the same reference numerals and description thereof will be omitted.

  The first thermocouple 71 for detecting the temperature of the low temperature shift unit 49 is disposed not near the inlet of the low temperature shift unit 49 but near the center in the vertical direction of the low temperature shift unit 49. Further, the second thermocouple 72 for detecting the temperature of the selective oxidizer 44 is provided not at the inlet of the selective oxidizer 44 but at a position slightly lower than the inlet.

  The above FPS3B reforming water control unit 65 removes CO via the temperature detected by the first thermocouple 71, the second thermocouple 72, and the third thermocouple 63 similar to the first embodiment. Since the temperature of the unit 15 is monitored and the flow rate of the reforming water W is controlled based on this temperature, the reaction of the catalytic reaction that easily maintains the CO removing unit 15 at a suitable temperature and removes carbon monoxide. Efficiency can be improved and carbon monoxide removal efficiency can be improved.

(Third embodiment)
Next, a hydrogen production apparatus (FPS) 3C according to the third embodiment will be described with reference to FIG. In addition, FPS3C differs in arrangement | positioning of the 2nd thermocouple (2nd sensor part) 81 and the 3rd thermocouple (water temperature detection sensor) 82 compared with FPS3A which concerns on 1st Embodiment. Therefore, FPS3C will be described with a focus on differences from FPS3A, and the same elements and structures will be denoted by the same reference numerals and description thereof will be omitted.

  The second thermocouple 81 for detecting the temperature of the selective oxidizer 44 is arranged not at the inlet of the selective oxidizer 44 but at the outlet of the selective oxidizer 44. Further, a third thermocouple (water temperature detection sensor) 82 for detecting the temperature of the reforming water W is provided in the first line S4a of the lower water channel S4.

  The reforming water control unit 65 of the FPS 3C described above has the same temperature as that detected by the first thermocouple 61, the second thermocouple 81, and the third thermocouple 82 as in the first embodiment. Since the temperature of the CO removal unit 15 is monitored and the flow rate of the reforming water W is controlled based on this temperature, it is easy to maintain the CO removal unit 15 at a suitable temperature, and the catalytic reaction that removes carbon monoxide. Thus, the carbon monoxide removal efficiency can be improved.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  For example, in the above embodiment, kerosene is used as the liquid raw material, but gasoline, naphtha, light oil, methanol, ethanol, DME (dimethyl ether), and biofuel using biomass may be used. In this case, the desulfurizer (desulfurization method) and the reformer (reformation method) are adapted to the characteristics of the liquid raw material to be used.

  As the noble metal-based steam reforming catalyst used for the reforming catalyst, a Group VII metal such as nickel, cobalt, iron, ruthenium, rhodium, iridium and platinum can be used. As the high temperature shift catalyst, a mixed oxide of Zn—Cu may be used, or a catalyst containing a noble metal such as platinum, ruthenium, or iridium may be used. Further, as the low temperature shift catalyst, a mixed oxide of Fe—Cr may be used, or a catalyst containing a noble metal such as platinum, ruthenium, or iridium may be used.

It is a figure showing the outline of the fuel cell system to which the hydrogen production device concerning a 1st embodiment of the present invention is applied. It is a figure showing the outline of the hydrogen production device concerning a 1st embodiment. It is a flowchart which shows the operation | movement procedure of the flow control of reforming water. It is a figure which shows typically the flow of the heat exchange between the water for reforming, and a CO removal part. It is a figure which shows the outline of the hydrogen production apparatus which concerns on 2nd Embodiment. It is a figure which shows the outline of the hydrogen production apparatus which concerns on 3rd Embodiment.

Explanation of symbols

  3A, 3B, 3C ... Hydrogen production equipment, 13 ... Reformer (reforming section), 41 ... Transformer (shift section), 44 ... Selective oxidizer (selective oxidation section), 47 ... High temperature shift section, 49 ... Low temperature Shift unit, 61, 71 ... first thermocouple (first sensor unit), 62, 72, 81 ... second thermocouple (second sensor unit), 63, 82 ... third thermocouple (water temperature) Detection sensor), 65 ... reforming water control unit (control unit), G1 ... reforming gas, W ... reforming water, S4 ... lower water channel (cooling line).

Claims (5)

A reforming unit that reforms a raw material for hydrogen production to generate a hydrogen-rich reformed gas;
A shift unit for removing carbon monoxide contained in the reformed gas from the reforming unit by an aqueous shift reaction;
A selective oxidation unit that selectively oxidizes carbon monoxide contained in the reformed gas from the shift unit;
A cooling line for cooling the shift unit and the selective oxidation unit with reforming water introduced into the reforming unit for the reforming;
A first sensor unit for detecting the temperature of the shift unit;
A second sensor unit for detecting the temperature of the selective oxidation unit;
A hydrogen production system comprising: a control unit that controls a flow rate of the reforming water flowing through the cooling line based on temperatures detected by the first sensor unit and the second sensor unit. apparatus. The supply amount of the raw material for hydrogen production supplied to the reforming unit is determined according to a desired generation amount of the reformed gas,
The reference supply amount of the reforming water supplied to the reforming unit is determined according to the supply amount of the raw material for hydrogen production,
When the temperature detected by the first sensor unit is equal to or higher than the first threshold value, or when the temperature detected by the second sensor unit is equal to or higher than the second threshold value, the control unit 2. The hydrogen production apparatus according to claim 1, wherein a flow rate of the reforming water is controlled so as to supply a surplus of the reforming water in addition to a reference supply amount. The shift unit is suitable for an aqueous shift reaction at a lower temperature than the high temperature shift unit and a low temperature shift unit disposed downstream of the reformed gas flow than the high temperature shift unit. And
The hydrogen production apparatus according to claim 1, wherein the first sensor unit is disposed at an inlet of the low temperature shift unit. The cooling line includes a first line connected to the selective oxidation unit so as to be able to transfer heat, and a second line connected to the shift unit so as to be able to transfer heat,
The hydrogen production apparatus according to any one of claims 1 to 3, wherein the first line is disposed upstream of the flow of the reforming water with respect to the second line. A water temperature detection sensor provided in the cooling line;
The control unit has a flow rate of reforming water flowing through the cooling line based on the temperature detected by the water temperature detection sensor in addition to the temperature detected by the first sensor unit and the second sensor unit. The hydrogen production apparatus according to any one of claims 1 to 4, wherein the hydrogen production apparatus is controlled.

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