JP4175432B2 - Reforming apparatus and operation method thereof - Google Patents

Description

  The present invention relates to a reforming apparatus for generating a reformed gas mainly composed of hydrogen by steam reforming a hydrocarbon-based raw fuel gas and an operation method thereof.

  2. Description of the Related Art Conventionally, a reforming apparatus is known that generates a reformed gas mainly composed of hydrogen by reforming a hydrocarbon-based raw fuel gas such as methane, propane, or butane by a steam reforming reaction. A typical use of the reformed gas is a fuel cell power generation fuel. In a normal reformer, CO gas is produced as a by-product during the steam reforming reaction and is contained in the reformed gas. This CO gas becomes the catalyst poison of the fuel cell and generates power. It will cause the decrease. Therefore, for example, as shown in Patent Document 1 and the like, in the reformer, in addition to the reforming reaction section in which the steam reforming reaction is performed, the CO concentration in the reformed gas is reduced to a level at which there is no problem. For this purpose, a shift reaction unit that reduces CO in the reformed gas obtained in the reforming reaction unit by an aqueous shift reaction and a CO gas remaining in the reformed gas processed in the shift reaction unit are selectively selected. A CO selective oxidation reaction section that is oxidized and further reduced is provided.

These three types of reaction units provided in the reformer are sequentially connected and arranged in series, and a series or cylindrical container having a gas flow path in each is filled with a predetermined catalyst. It is formed. As a catalyst of each reaction section in the reformer, a reforming catalyst such as a nickel-based, ruthenium-based, or rhodium-based catalyst as a steam reforming reaction catalyst, a copper-zinc based shift catalyst as a catalyst for an aqueous shift reaction, Further, an oxidation catalyst such as platinum or ruthenium is used as a catalyst for the CO selective oxidation reaction.
Japanese Unexamined Patent Publication No. 7-12001

  However, in general, the copper-based shift catalyst in the shift reaction section is filled in the reaction vessel in a reduced state, and this shift catalyst is oxidized when it comes into contact with oxygen, and the catalytic performance is lowered. Further, if the shift catalyst absorbs moisture when the temperature of the reforming reaction is stopped and the temperature is lowered, the shift catalyst may collapse due to evaporation of moisture due to a temperature rise at the time of starting the reformer. Therefore, when a reforming gas containing hydrogen as a main component is generated using the reforming apparatus as described above, an oxygen pressure is reduced in the reforming apparatus due to a decrease in internal pressure due to a temperature decrease in the reforming apparatus when the reforming apparatus is stopped. Is mixed and the shift catalyst is oxidized, and when the reformer is repeatedly started and stopped, the shift catalyst gradually deteriorates. Also, if water vapor remains in the shift reaction section when the reformer is stopped, the water vapor condenses due to a decrease in temperature in the reformer and the shift catalyst absorbs water. The water absorbed by the catalyst may evaporate and the shift catalyst may collapse.

  Here, in the reformer used in the conventional large-sized or medium-sized fuel cell power generation system, continuous operation with almost no start / stop operation is performed. A method has been used in which an inert gas is supplied into the reaction tube and the gas in the reaction tube of each reaction section is replaced with an inert gas. Furthermore, such a problem of deterioration has been addressed by filling the catalyst in a predetermined amount or more so that no problem occurs even if the catalyst is somewhat deteriorated. However, such a method cannot be applied to a small fuel cell power generation system because the reformer becomes large.

  The present invention has been made in view of the above points, and provides a reforming apparatus suitable for a small-sized fuel cell power generation system and a method for operating the same, in which the shift catalyst does not deteriorate even if the start and stop are repeated. It is for the purpose.

  The reforming apparatus according to claim 1 of the present invention includes a reforming reaction section 1 that is supplied with hydrocarbon-based raw fuel gas and steam and generates a hydrogen-rich reformed gas by a steam reforming reaction, and this reforming. The reformed gas generated in the reaction unit 1 is supplied and the CO gas contained in the reformed gas is reduced by the aqueous shift reaction, and the reformed gas delivered from the shift reaction unit 2 In a reformer including a CO selective oxidation reaction unit 3 that oxidizes and reduces contained CO gas and a reformed gas outlet passage 13 that guides the reformed gas to the outside, after the operation of the reformer is stopped And a gas supply control means for supplying at least the raw fuel gas to the shift reaction section 2 so as to compensate for gas contraction due to a temperature drop in a state in which the reformed gas outlet flow path 13 is closed. is there.

  The operation method of the reformer according to claim 2 of the present invention includes a reforming reaction section 1 that is supplied with hydrocarbon-based raw fuel gas and steam and generates a hydrogen-rich reformed gas by a steam reforming reaction; The reformed gas generated in the reforming reaction unit 1 is supplied, the shift reaction unit 2 for reducing the CO gas contained in the reformed gas by the aqueous shift reaction, and the reforming sent from the shift reaction unit 2 An operation method of a reformer comprising a CO selective oxidation reaction unit 3 that oxidizes and reduces CO gas contained in a gas, and a reformed gas outlet passage 13 that guides the reformed gas to the outside, The raw fuel gas is supplied to at least the shift reaction section 2 so as to compensate for gas contraction due to a temperature drop with the reformed gas outlet passage 13 closed after the reformer is stopped. It is.

  According to a third aspect of the present invention, in the second aspect, after the operation of the reformer is stopped, at least the water vapor in the shift reaction unit 2 is pushed out with the raw fuel gas, and then the reformed gas outlet passage 13 is closed. The raw fuel gas is supplied to at least the shift reaction unit 2.

  According to the present invention, the pressure in the shift reaction unit 2 can be maintained at a normal pressure with the raw fuel gas, and oxygen enters the shift reaction unit 2 when the operation of the reformer is stopped. It is possible to prevent the shift catalyst from being oxidized to deteriorate the catalyst performance.

  Hereinafter, the best mode for carrying out the present invention will be described.

The reforming apparatus of the present invention includes a reforming reaction section 1 that generates a hydrogen-rich reformed gas from a hydrocarbon-based raw fuel gas such as methane, propane, and butane by steam reforming reaction, and reformed gas. A shift reaction unit 2 for converting most of the CO gas contained in the fuel cell and poisoning the platinum-based or alloy-based electrode catalyst of the fuel cell to deteriorate electrode characteristics into CO ₂ by an aqueous shift reaction; And a CO selective oxidation reaction section 3 that oxidizes the CO gas still remaining in the reformed gas having a reduced CO concentration into CO ₂ by a CO selective oxidation reaction. Each of these three reaction parts is formed by filling a cylindrical container or the like with a catalyst. Here, a reforming catalyst such as nickel, ruthenium or rhodium is used for the steam reforming reaction, a copper-zinc shift catalyst is used for the aqueous shift reaction, and a CO oxidation such as platinum or ruthenium is used for the CO selective oxidation reaction. Each catalyst is used, and each catalyst is filled with these catalysts.

  Here, the reforming reaction unit 1 and the shift reaction unit 2 are connected and communicated with each other through a reforming reaction unit flow path 11 that sends the reformed gas generated in the reforming reaction unit 1 into the shift reaction unit 2. The shift reaction unit 2 and the CO selective oxidation reaction unit 3 are connected by a shift reaction unit flow path 12 that sends the reformed gas whose CO gas is reduced in the shift reaction unit 2 to the CO selective oxidation reaction unit 3. It communicates. The CO selective oxidation reaction section 3 is connected to a reformed gas outlet flow path 13 for supplying the reformed gas further reduced in CO gas in the CO selective oxidation reaction section 3 to the outside of the reformer. The reforming reaction section 1 is connected to one end of a reaction gas supply channel 14 for supplying hydrocarbon-based raw fuel gas and water vapor to the reforming reaction section 1. The other end of the reaction gas supply channel 14 is joined by connecting one end of a water vapor supply channel 15 through which water vapor is sent and a raw fuel gas supply channel 16 through which raw fuel gas is sent. Also, an appropriate water vapor generator 7 is connected to the other end of the water vapor supply channel 15, and a raw fuel gas supply device such as a gas cylinder filled with the raw fuel gas is connected to the other end of the raw fuel gas supply channel 16. 8 is connected. One end of an air supply channel 17 for supplying air to the CO selective oxidation reaction unit 3 is connected to the shift reaction unit channel 12, and an appropriate air supply means 9 is connected to the other end of the air supply channel 17. Are connected. The air supply channel 17 is for supplying oxygen necessary for the CO selective oxidation reaction to the CO selective oxidation reaction unit 3. In addition, each of the water vapor supply flow path 15, the raw fuel gas supply flow path 16, the air supply flow path 17, and the reformed gas outlet flow path 13 has open / close valves 18, 19, 20, which open and close the flow of each flow path. 21 and a control unit 10 for controlling the opening / closing operation of each on-off valve 18, 19, 20, 21 is provided, and the control unit 10 and each on-off valve 18, 19, 20, 21 constitute gas supply control means. It is.

  Further, the reforming apparatus of the present invention is provided with a combustion section 4 that heats each reaction section and advances the reaction in each reaction section. The combustion unit 4 is provided with a combustion means 5 such as a burner for burning combustion fuel or a combustion catalyst. This combustion section 4 is connected to each reaction section so as to send heat generated by the combustion means 5 to each reaction section.

  Further, in the reforming apparatus shown in FIG. 1, the reforming reaction unit 1 is provided with temperature determination means 6 for determining that the temperature in the reforming reaction unit 1 has become a predetermined set value or less. While the reformer is operating as the control unit 10, each open / close valve 18 of the water vapor supply channel 15, the raw fuel gas supply channel 16, the reformed gas outlet channel 13, and the air supply channel 17. , 19, 20, 21 are opened to maintain the flow of each flow path so that reformed gas can be generated, and the air supply flow path 17 is opened and closed when the operation of the reformer is stopped. After the valve 20 is closed and the supply of air to the CO selective oxidation reaction unit 3 is stopped and the operation of the reformer is stopped, it is determined that the temperature in the reformer has become a predetermined set value or less. At the time determined by the means 6, the on-off valve 18 of the water vapor supply channel 15 is closed to shut off the flow of the water vapor supply channel 15, and the raw fuel gas supply channel 16 and the reformed gas outlet channel 13 The on-off valves 19 and 21 are kept open to supply raw fuel gas. The flow between the flow path 16 and the reformed gas outlet flow path 13 is maintained, and after a certain time has passed, the on-off valve 21 of the reformed gas outlet flow path 13 is closed to shut off the flow of the reformed gas outlet flow path 13. In this way, a valve that controls the on-off valves 18, 19, 20, and 21 is used. Here, the above-mentioned predetermined set value is appropriately set below the temperature at which the raw fuel gas composed of hydrocarbon is thermally decomposed and carbon deposition occurs. For example, when butane gas is used as the raw fuel gas, it is 300 ° C. Is set to a degree.

  In this way, when the temperature in each reaction section of the reforming reaction apparatus is equal to or higher than the temperature at which the raw fuel gas is thermally decomposed and carbon is precipitated, the reforming apparatus is stopped when the operation of the reforming apparatus is stopped. The supply of steam to each of the reaction parts is maintained, and the steam is supplied together with the raw fuel to each reaction part of the reforming reaction apparatus. At this time, the reaction rate of the steam reforming reaction between the raw fuel gas and the steam is sufficiently faster than the reaction rate of the pyrolysis reaction of the raw fuel gas, so that the steam reaction takes precedence over the pyrolysis reaction. In this state, when the reforming reaction section 1 in the reformer is cooled and the raw fuel gas is thermally decomposed to a temperature lower than the temperature at which carbon deposition occurs, supply of steam to the reforming reaction section 1 Is stopped, and steam is no longer supplied to the shift reaction unit 2 and the CO selective oxidation reaction unit 3. At this time, the water vapor remaining in each reaction section of the reformer is pushed out of the reformer from the reformed gas outlet passage 13 by the raw fuel, and the water vapor in each reaction section in the reformer is removed. Then, after a certain period of time has passed since the supply of water vapor to the reforming reaction section 1 was stopped, when all the water vapor in the reformer has been removed, the flow of the reformed gas outlet passage 13 is closed and the raw fuel gas is modified. The supply to the quality reaction unit 1 is maintained. For this reason, even if the reformer is stopped and the temperature of each reaction section decreases and the gas in each reaction section contracts, the pressure in each reaction section is maintained at normal pressure with the raw fuel gas. Therefore, even if the temperature of each reaction part during operation of the reformer is higher than the temperature at which the raw fuel gas is thermally decomposed and carbon is precipitated, the raw fuel gas is not used after the operation of the reformer is stopped. Can be prevented from thermally decomposing in each reaction section of the reforming apparatus, so as to prevent carbon from being deposited in the reforming apparatus, and after the operation of the reforming apparatus is stopped, the shift reaction section 2 is stopped. After the shift catalyst absorbs water, it is heated when the reformer is started, and the moisture in the shift catalyst expands into water vapor to prevent the shift catalyst from collapsing. It is something that can be done. Further, while the operation of the reformer is stopped, the reformer is maintained at a normal pressure by the raw fuel gas, so that oxygen enters the shift reaction unit 2 to oxidize the shift catalyst, and the catalyst performance. Can be prevented from decreasing.

  Further, in the reforming apparatus shown in FIG. 1, the control of the opening / closing valve 19 of the raw fuel gas supply flow path 16 by the control unit 10 is changed, and the raw fuel gas supply flow path 16 is stopped when the operation of the reforming apparatus is stopped. The open / close valves 19 and 20 of the air supply flow path 17 are closed, and the open / close valve 18 of the water vapor supply flow path 15 and the open / close valve 19 of the raw fuel gas supply flow path 16 are opened to improve the water vapor supply flow path 15. When the temperature determining means 6 determines that the temperature in the reformer is maintained below the predetermined set value while maintaining the flow of the quality gas supply flow path, the on-off valve 18 of the water vapor supply flow path 15 is closed. As a state, the flow of the water vapor supply passage 15 is shut off, and the on-off valves 19 and 21 of the raw fuel gas supply passage 16 and the reformed gas outlet passage 13 are opened, and the raw fuel gas supply passage 16 and the reformed gas are opened. Maintains the flow of the outlet channel 13 and further elapses After that, the on-off valve 21 of the reformed gas outlet passage 13 may be closed to control the on-off valves 18, 19, 20, and 21 so as to shut off the flow of the reformed gas outlet passage 13. . In this way, after the operation of the reformer is stopped, if the temperature of each reaction section in the reformer is equal to or higher than the temperature at which the raw fuel gas is thermally decomposed and carbon is deposited, reforming is performed. Since only the water vapor is supplied to each reaction part of the apparatus, it is possible to reliably prevent carbon from being deposited in the reformer due to thermal decomposition of the raw fuel gas. Further, when the temperature of each reaction section is equal to or lower than the temperature at which the raw fuel gas is thermally decomposed and carbon is deposited, the supply of water vapor to the reforming reaction section 1 is stopped and the raw fuel is treated in the same manner as described above. After the gas is supplied to the reforming reaction section 1 and the water vapor in each reaction section is removed, the on-off valve 21 of the reformed gas outlet flow path 13 is closed to keep the pressure in each reaction section at normal pressure. It is.

  Here, a temperature measuring device such as a thermocouple, thermistor, infrared thermometer or the like is used as the temperature determining means 6, and the temperature in the reforming reaction unit 1 measured by this temperature measuring device is controlled. It can output to the part 10. In this way, it can be accurately determined by measuring the temperature in the reforming reaction section 1 that the temperature in the reformer has become equal to or lower than a predetermined set value. It is possible to accurately determine the switching timing of supply / stop of the raw fuel gas and water vapor to the section 1.

  Further, as the temperature determination means 6, a timer that outputs a signal to the control unit 10 when the time taken until the reforming reaction unit 1 reaches a certain set value after the operation of the reformer is stopped may be used. it can. Here, the time taken from when the operation of the reforming apparatus is stopped until the reforming reaction unit 1 reaches a certain set value is measured in advance. In this way, it can be accurately determined by time control that the temperature in the reformer is equal to or lower than a predetermined set value, so that the raw fuel gas and water vapor to the reforming reaction section 1 can be determined. It is possible to accurately determine the supply / stop switching timing.

  The reformer shown in FIG. 2 can be used when the temperature of each reaction section in which the reformer is operating is equal to or lower than the temperature at which the raw fuel gas is thermally decomposed and carbon is deposited. In the reformer shown in FIG. 2, an on-off valve 22 is provided in the reforming reaction section flow path 11, and a raw fuel gas sub-flow path 23 branched from the raw fuel gas supply flow path 16 is connected to the shift reaction section 2. Further, as the on-off valve 19 provided in the raw fuel gas supply flow path 16, a three-way valve is provided at the branch point between the raw fuel gas supply flow path 16 and the raw fuel gas sub-flow path 23. Further, as the control unit 10, the open / close valves 18, 20, and 21 of the steam supply channel 15, the reformed gas outlet channel 13, and the air supply channel 17 are opened while the reformer is operating. The flow of each flow path is maintained, and the on-off valve 19 of the raw fuel gas supply flow path 16 is opened to the downstream and upstream sides of the raw fuel gas supply flow path 16 and the raw fuel gas supply flow path 16 The reformed gas can be generated by shutting off the flow with the fuel gas sub-flow channel 23, and when the operation of the reformer is stopped, the on-off valve 18 of the water vapor supply channel 15 is opened. In the closed state, the flow of the water vapor supply flow path 15 is blocked, the flow of the raw fuel gas supply flow path 16 between the downstream side and the upstream side of the raw fuel gas supply flow path 16 is blocked, and the raw fuel gas supply flow path 16 16 and the flow between the raw fuel gas sub-passage 23 are opened The on-off valve 21 of the reformed gas outlet passage 13 is maintained in the open state to maintain the flow of the reformed gas outlet passage 13 and the on-off valve 22 of the reforming reaction section passage 11 is closed. Each of the on-off valves is configured to shut off the flow of the reforming gas outlet passage 13 by shutting off the passage of the quality reaction section passage 11 and closing the on-off valve 21 of the reformed gas outlet passage 13 after a certain time has passed. The control unit 10 and the on-off valves 18, 19, 20, 21, and 22 constitute a gas supply control means using what controls the 18, 19, 20, 21, and 22. Moreover, the temperature determination means 6 is not provided. Other configurations are the same as those shown in FIG.

  In this way, when the operation of the reformer is stopped, the supply of water vapor and raw fuel gas to the reforming reaction unit 1 is stopped and the gas flows between the reforming reaction unit 1 and the shift reaction unit 2. Is blocked, and all the gas flow between the reforming reaction unit 1 and the outside of the reforming reaction unit 1 is blocked. At this time, water vapor is not supplied to the shift reaction unit 2 and the CO selective oxidation reaction unit 3, but the supply of the raw fuel gas is maintained. At this time, water vapor remaining in the shift reaction section 2 and the CO selective oxidation reaction section 3 of the reformer is pushed out of the reformer gas from the reformed gas outlet flow path 13 by the raw fuel gas, and each shift in the reformer is performed. Water vapor in the reaction unit 2 and the CO selective oxidation reaction unit 3 is removed. Then, after a certain period of time has elapsed since the supply of water vapor to the reforming reaction unit 1 was stopped, when all the water vapor in the shift reaction unit 2 and the CO selective oxidation reaction unit 3 has been removed, the flow of the reformed gas outlet flow channel 13 is started. At the same time, the supply of the raw fuel gas to the shift reaction unit 2 is maintained, and even if the operation of the reformer is stopped to lower the temperature of each reaction unit and the gas in each reaction unit contracts, The pressure in the shift reaction unit 2 and the CO selective oxidation reaction unit 3 is maintained at normal pressure by the fuel gas. Therefore, when the temperature of each reaction section in which the reformer is operating is equal to or lower than the temperature at which the raw fuel gas is thermally decomposed and carbon is deposited, the reformer shown in FIG. Water vapor is prevented from remaining in the shift reaction unit 2 after the operation of the apparatus is stopped, and after the shift catalyst absorbs water, it is heated when the reformer is started up, and the water in the shift catalyst expands as water vapor. The shift catalyst can be prevented from collapsing, and further, when the operation of the reformer is stopped, oxygen enters the shift reaction unit 2 to oxidize the shift catalyst and thereby perform catalytic performance. Can be prevented. Here, the reformer shown in FIG. 3 is used when the temperature of each reaction section in which the reformer is operating is equal to or lower than the temperature at which the raw fuel gas is thermally decomposed and carbon is deposited. Therefore, after the operation of the reformer is stopped, it is not necessary to maintain the supply of water vapor until the temperature of each reaction unit of the reformer decreases, and after the operation of the reformer is stopped, the shift reaction unit The water vapor remaining in 2 can be quickly removed.

  In the reformer shown in FIG. 3, the temperature determination means 6 is provided in the reforming reaction section 1, and when the reforming apparatus is operated as the control section 10, the steam supply flow path 15, the reformed gas outlet flow The on-off valves 18, 20, 21 of the passage 13 and the air supply passage 17 are opened to maintain the flow of the passages, and the on-off valve 19 of the raw fuel gas supply passage 16 is connected to the raw fuel gas supply passage. The flow of the downstream side and the upstream side of 16 is opened and the flow of the raw fuel gas supply channel 16 and the raw fuel gas subchannel 23 is shut off so that the reformed gas can be generated. After the operation of the reformer is stopped, when the temperature determination means 6 determines that the temperature in the reformer has become equal to or lower than a predetermined set value, the steam supply channel 15 and the air supply channel 17. The on-off valves 18 and 20 are closed and the water vapor supply passage 15 and the air The flow of the supply flow path 17 is blocked, the flow of the raw fuel gas supply flow path 16 between the downstream side and the upstream side of the raw fuel gas supply flow path 16 is blocked, and the raw fuel gas supply flow path 16 and the raw fuel The flow to and from the gas sub-flow channel 23 is opened, the on-off valve 21 of the reformed gas outlet flow channel 13 is maintained in the open state, and the flow of the reformed gas outlet flow channel 13 is maintained to perform reforming. The on-off valve 22 of the reaction section flow path 11 is closed to shut off the flow of the reforming reaction section flow path 11, and after a predetermined time has passed, the on-off valve 21 of the reformed gas outlet flow path 13 is closed to reform gas. What controls each on-off valve 18, 19, 20, 21, and 22 so that the distribution | circulation of the derivation | leading-out flow path 13 is interrupted | blocked, and this control part 10 and each on-off valve 18, 19, 20, 21, and 22 gas It constitutes supply control means. Other configurations are the same as those shown in FIG.

  In this way, when the temperature in each reaction section of the reforming reaction apparatus is equal to or higher than the temperature at which the raw fuel gas is thermally decomposed and carbon is precipitated, the reforming apparatus is stopped when the operation of the reforming apparatus is stopped. The supply of water vapor to each reaction part is maintained. In this state, when the reforming reaction section 1 in the reforming apparatus is cooled and the raw fuel gas is thermally decomposed to a temperature lower than the temperature at which carbon deposition occurs, the steam and raw material to the reforming reaction section 1 are reduced. The supply of the fuel gas is stopped and the gas flow between the reforming reaction unit 1 and the shift reaction unit 2 is blocked, and the gas flow between the reforming reaction unit 1 and the outside of the reforming reaction unit 1 is all blocked. The At this time, water vapor is not supplied to the shift reaction unit 2 and the CO selective oxidation reaction unit 3, but the supply of the raw fuel gas is maintained. At this time, water vapor remaining in the shift reaction section 2 and the CO selective oxidation reaction section 3 of the reformer is pushed out of the reformer gas from the reformed gas outlet flow path 13 by the raw fuel gas, and each shift in the reformer is performed. Water vapor in the reaction unit 2 and the CO selective oxidation reaction unit 3 is removed. Then, after a certain period of time has elapsed since the supply of water vapor to the reforming reaction unit 1 was stopped, when all the water vapor in the shift reaction unit 2 and the CO selective oxidation reaction unit 3 has been removed, the flow of the reformed gas outlet flow channel 13 is started. At the same time, the supply of the raw fuel gas to the shift reaction unit 2 is maintained, and even if the operation of the reformer is stopped to lower the temperature of each reaction unit and the gas in each reaction unit contracts, The pressure in the shift reaction unit 2 and the CO selective oxidation reaction unit 3 is maintained at normal pressure by the fuel gas. Therefore, even if the temperature of each reaction part during operation of the reformer is higher than the temperature at which the raw fuel gas is thermally decomposed and carbon is precipitated, the raw fuel gas is not used after the operation of the reformer is stopped. It is possible to prevent the carbon from being deposited in the reforming apparatus by preventing thermal decomposition. Further, after the operation of the reformer is stopped, water vapor is prevented from remaining in the shift reaction unit 2, and after the shift catalyst absorbs water, it is heated when the reformer is started, so that the water in the shift catalyst becomes water vapor. Thus, the shift catalyst can be prevented from expanding and collapsing. Furthermore, when the operation of the reformer is stopped, oxygen can enter the shift reaction section 2 to oxidize the shift catalyst and reduce the catalyst performance.

It is the schematic which shows an example of embodiment of this invention. It is the schematic which shows the other example of embodiment of this invention. It is the schematic which shows the other example of embodiment of this invention.

Explanation of symbols

1 reforming reaction section 2 shift reaction section 3 CO selective oxidation reaction section 13 reformed gas outlet flow path

Claims (3)

  A hydrocarbon-based raw fuel gas and steam are supplied, a reforming reaction section that generates a hydrogen-rich reformed gas by a steam reforming reaction, and a reformed gas generated in the reforming reaction section is supplied, A shift reaction section for reducing CO gas contained in the reformed gas by an aqueous shift reaction, a CO selective oxidation reaction section for oxidizing and reducing CO gas contained in the reformed gas sent from the shift reaction section, In a reformer having a reformed gas outlet channel for leading the reformed gas to the outside, after the operation of the reformer is stopped, the gas contraction due to a temperature drop while the reformed gas outlet channel is closed A reformer comprising gas supply control means for supplying raw fuel gas to at least the shift reaction section so as to compensate for the above.   A hydrocarbon-based raw fuel gas and steam are supplied, a reforming reaction section that generates a hydrogen-rich reformed gas by a steam reforming reaction, and a reformed gas generated in the reforming reaction section is supplied, A shift reaction section for reducing CO gas contained in the reformed gas by an aqueous shift reaction, a CO selective oxidation reaction section for oxidizing and reducing CO gas contained in the reformed gas sent from the shift reaction section, A reformer operating method comprising a reformed gas outlet channel for leading the reformed gas to the outside, and after the reformer has stopped operating, the reformed gas outlet channel is closed, A method for operating a reformer, characterized in that raw fuel gas is supplied to at least the shift reaction section so as to compensate for gas contraction due to temperature drop.   After the operation of the reformer is stopped, at least the water vapor in the shift reaction unit is pushed out with the raw fuel gas, and then the raw fuel gas is supplied to at least the shift reaction unit with the reformed gas outlet flow path closed. A method for operating the reformer according to claim 2.

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