JP4556393B2 - Fuel reformer - Google Patents

Description

  The present invention relates to a fuel reformer that generates a hydrogen-rich reformed gas by steam reforming a hydrocarbon-based fuel such as city gas, natural gas, LPG, or alcohol, and in particular, supplied to the fuel reformer. Among the generated steam, even the steam that does not contribute to the reforming catalyst reaction in the reforming catalyst layer is prevented from increasing the pressure loss of the entire fuel reformer as it is supplied to the reforming catalyst layer. The present invention relates to a fuel reformer that can be used.

  Conventionally, as a fuel reformer using a steam reforming system for a polymer electrolyte fuel cell power generator, for example, one described in WO00 / 63114 is known. In the fuel reformer having a multi-cylindrical structure described in WO00 / 63114, a reforming catalyst layer and a CO shift catalyst layer are provided. Specifically, a reforming catalyst layer constituting a part of the steam channel (specifically, a part of the steam channel) outside the combustion gas channel (between the cylinder 14 and the cylinder 68 in FIG. 3 of WO 00/63114). 13) is disposed, and the CO shift catalyst layer (11) is disposed outside the water vapor channel.

  However, in the fuel reformer described in WO00 / 63114, water vapor required for reacting hydrocarbon fuel or the like in the reforming catalyst layer and the CO shift catalyst layer is generated in the reforming catalyst layer and the CO shift catalyst layer. The water is combined at the upstream, first supplied to the reforming catalyst layer, and then the water vapor that has passed through the reforming catalyst layer is supplied to the CO shift catalyst layer. In other words, in the fuel reformer described in WO00 / 63114, excess steam that does not contribute to the reforming catalyst reaction in the reforming catalyst layer out of the steam supplied to the fuel reformer also forms the reforming catalyst layer. It has been supplied. For this reason, as excess steam is supplied to the reforming catalyst layer, the pressure loss of the entire fuel reformer increases. If the pressure loss of the entire fuel reformer increases, the auxiliary power must be increased, and the temperature of excess steam must be increased to the reforming catalyst reaction temperature. End up. As a result, the heat flux load of the reforming catalyst layer increases, and the structure of the reforming catalyst layer becomes complicated in order to promote heat transfer.

WO00 / 63114

  In view of the above-described problems, the present invention provides that steam, which does not contribute to the reforming catalyst reaction in the reforming catalyst layer, among the steam supplied to the fuel reformer is supplied to the reforming catalyst layer. An object of the present invention is to provide a fuel reformer that can avoid an increase in pressure loss of the entire fuel reformer.

According to the invention described in claim 1, it comprises a reforming catalyst layer and a CO shift catalyst layer ,
In a multi-cylinder fuel reformer in which a steam channel is disposed outside a combustion gas channel, and a CO removal catalyst layer and the CO shift catalyst layer are disposed outside the steam channel ,
Distributing means for distributing the steam supplied to the fuel reformer to the reforming catalyst layer and the CO conversion catalyst layer ,
Forming a plurality of CO removal catalyst steam input holes in a partition tube between the steam flow path and the CO removal catalyst layer;
A fuel reformer is provided in which a plurality of steam inlet holes for a CO shift catalyst are formed in a partition tube between the steam flow path and the CO shift catalyst layer .

According to the invention described in claim 2, the plurality of CO removal catalyst steam inlet holes are evenly arranged in the circumferential direction and the central axis direction of the fuel reformer,
2. The fuel reformer according to claim 1, wherein the plurality of CO conversion catalyst steam inlet holes are arranged uniformly in a circumferential direction and a central axis direction of the fuel reformer.

The fuel reformer according to claim 1 is provided with a distribution means for distributing the steam supplied to the fuel reformer to the reforming catalyst layer and the CO shift catalyst layer. Specifically, for example, of the steam supplied to the fuel reformer, the steam necessary for the reforming catalyst reaction in the reforming catalyst layer is distributed to the reforming catalyst layer by the distributing means and supplied to the fuel reformer. At least a portion of the steam that is not required for the reforming catalyst reaction in the reforming catalyst layer is distributed to the CO conversion catalyst layer by the distributing means. Therefore, it is possible to avoid an increase in the pressure loss of the entire fuel reformer as all the water vapor supplied to the fuel reformer is supplied to the reforming catalyst layer. In other words, of the steam supplied to the fuel reformer, even the steam that does not contribute to the reforming catalyst reaction in the reforming catalyst layer is supplied to the reforming catalyst layer, so that the pressure loss of the entire fuel reformer Can be prevented from rising.

The fuel reformer according to claim 1 , further comprising a CO removal catalyst layer, wherein water vapor required for the reforming catalyst reaction in the reforming catalyst layer out of the water vapor supplied to the fuel reformer is a distributing means. Of the water vapor distributed to the reforming catalyst layer by the gas generator and supplied to the fuel reformer, the water vapor necessary for the CO shift catalytic reaction in the CO shift catalyst layer is distributed to the CO shift catalyst layer by the distributing means, and fuel reforming is performed. Of the water vapor supplied to the vessel, the water vapor required for the CO removal catalyst reaction in the CO removal catalyst layer is distributed to the CO removal catalyst layer by the distribution means. Therefore, it is possible to avoid an increase in the pressure loss of the entire fuel reformer as all the water vapor supplied to the fuel reformer is supplied to the reforming catalyst layer. In other words, of the steam supplied to the fuel reformer, even the steam that does not contribute to the reforming catalyst reaction in the reforming catalyst layer is supplied to the reforming catalyst layer and the pressure loss of the entire fuel reformer Can be prevented from rising.

3. The fuel reformer according to claim 1 or 2 , wherein the multi-cylindrical integrated fuel reformer includes a combustion gas flow path, a water vapor flow path, a CO removal catalyst layer + a CO shift catalyst layer (CO removal catalyst layer) from the inside. And the CO shift catalyst layer are arranged side by side in the direction of the central axis of the fuel reformer, and it is optional whether the CO removal catalyst layer is positioned above or below the CO shift catalyst layer. .) Are arranged in this order. The thermal energy of the combustion gas is transmitted to water vapor (may be water instead of water vapor at the inlet of the water vapor flow path), and the superheated water vapor is combined with the raw fuel. A plurality of CO removal catalyst for steam charged holes are formed in the partition cylinder with vapor duct and the CO removal catalyst layer, even a plurality of CO removal catalyst for steam charged hole thereof in the circumferential direction and the central axis direction of the fuel reformer Is arranged. In addition, a plurality of steam inlet holes for the CO shift catalyst are formed in a partition tube between the steam flow path and the CO shift catalyst layer, and the plurality of steam shift holes for the CO shift catalyst are in the circumferential direction and the central axis direction of the fuel reformer. They are evenly arranged. Furthermore, of the steam supplied to the fuel reformer, the steam necessary for the reforming catalyst reaction in the reforming catalyst layer is distributed to the reforming catalyst layer, and of the steam supplied to the fuel reformer, CO The water vapor necessary for the CO removal catalyst reaction in the removal catalyst layer is distributed to the CO removal catalyst layer through the CO removal catalyst water vapor input hole, and of the water vapor supplied to the fuel reformer, the CO in the CO conversion catalyst layer. The total area of the plurality of CO removal catalyst steam injection holes and the plurality of CO conversion catalyst for the CO conversion catalyst so that the steam required for the conversion catalyst reaction is distributed to the CO conversion catalyst layer through the CO conversion catalyst steam injection hole The total area of the steam inlet holes and the area of the steam passage leading to the reforming catalyst layer are set. Specifically, the steam flow rate introduced into the reforming catalyst layer is a flow rate that contributes to the reforming reaction, and the steam flow rate introduced into the CO shift catalyst layer is a flow rate that contributes to the CO shift reaction, and CO removal. The flow rate of water vapor introduced into the catalyst layer improves the CO selectivity of the CO selective oxidation reaction by increasing the partial pressure of water vapor in the reformed gas, and a polymer electrolyte fuel cell is connected further downstream. In this case, the flow rate is set to have a humidifying effect and improve the performance of the fuel cell.

  Accordingly, the water vapor flow rate required for the reforming catalyst layer, the water vapor flow rate required for the CO shift catalyst layer, and the water vapor flow rate required for the CO removal catalyst layer can be obtained by a simple method that does not require addition of complicated control equipment. It becomes possible to distribute. As a result, the pressure loss of the entire fuel reformer is reduced, the increase in auxiliary power is prevented, the heat flux load of the reforming catalyst layer is reduced, and the heat transfer structure of the reforming catalyst layer is simplified. can do.

That is, in the fuel reformer according to claims 1 and 2 , of the steam supplied to the fuel reformer, the steam necessary for the reforming catalyst reaction in the reforming catalyst layer is converted into a steam removal hole for CO removal catalyst. Among the water vapor that is distributed to the reforming catalyst layer without passing through both the steam inlet holes for CO conversion catalyst and the CO conversion catalyst and is supplied to the fuel reformer, the water vapor necessary for the CO removal catalyst reaction in the CO removal catalyst layer is The steam required for the CO shift catalyst reaction in the CO shift catalyst layer out of the steam supplied to the CO reforming catalyst layer via the CO removal catalyst steam feed hole and supplied to the fuel reformer is the CO shift catalyst steam. It is distributed to the CO conversion catalyst layer through the charging hole. Therefore, it is possible to avoid an increase in the pressure loss of the entire fuel reformer as all the water vapor supplied to the fuel reformer is supplied to the reforming catalyst layer. In other words, of the steam supplied to the fuel reformer, even the steam that does not contribute to the reforming catalyst reaction in the reforming catalyst layer is supplied to the reforming catalyst layer and the pressure loss of the entire fuel reformer Can be prevented from rising.

  FIG. 1 is a schematic configuration diagram schematically showing one embodiment of a fuel reformer of the present invention. As shown in FIG. 1, in the fuel reformer of this embodiment, the gas burned in the burner 1 first flows downward in the furnace 2 while gradually giving the thermal energy to the reforming catalyst layer 9. To go. Next, the combustion gas turns back at the bottom of the furnace 2 and moves outward. Next, the combustion gas flows upward between the reforming catalyst layer 9 and the heat insulating material 19 while giving the thermal energy to the outer portion of the reforming catalyst layer 9. When the combustion gas reaches the upper folded portion, the combustion gas temperature is about 300 ° C.

  Thereafter, while the combustion gas flows downward in the combustion gas flow path 3, the combustion gas gives heat to water or water vapor in the water vapor flow path 6 and is discharged out of the system via the exhaust gas nozzle 4. The combustion gas temperature when the combustion gas is discharged out of the system varies depending on the temperature of water or steam supplied to the fuel reformer, but is about 90 ° C to 130 ° C.

  On the other hand, the water or steam supplied to the fuel reformer is fed into the steam channel 6 through the injection nozzle 5 and receives heat from the combustion gas in the combustion gas channel 3 in the steam channel 6. It becomes superheated steam at about 120 ° C.

  A CO shift catalyst layer 12, an alumina ball layer 13, and a CO removal catalyst layer 14 are arranged on the outer side of the water vapor channel 6 in order from the lower side in the central axis direction of the fuel reformer (the vertical direction in FIG. 1). Yes. For the CO selective oxidation reaction in the CO removal catalyst layer 14, air supplied through the air injection nozzle 15 is used. A plurality of water vapor input holes 17 are formed in the partition tube between the water vapor flow path 6 and the CO shift catalyst layer 12. The steam introduction holes 17 are arranged substantially evenly in the circumferential direction and the central axis direction (vertical direction in FIG. 1) of the fuel reformer so that the steam is uniformly supplied to the CO shift catalyst layer 12. In addition, the total area of the plurality of water vapor introduction holes 17 is the difference between the water vapor flow rate introduced into the CO shift catalyst layer 12 and the water vapor flow rate introduced into the other catalyst layers (reforming catalyst layer 9, CO removal catalyst layer 14). The pressure loss is set in consideration of distribution.

  A plurality of steam inlet holes 18 are formed in the partition tube between the steam channel 6 and the CO removal catalyst layer 14. The steam introduction holes 18 are arranged substantially evenly in the circumferential direction and the central axis direction (vertical direction in FIG. 1) of the fuel reformer so that the steam is uniformly supplied to the CO removal catalyst layer 14. In addition, the total area of the plurality of water vapor introduction holes 18 is determined by the flow rate of water vapor introduced into the CO removal catalyst layer 14 and the flow rate of water vapor introduced into other catalyst layers (reforming catalyst layer 9 and CO shift catalyst layer 12). The pressure loss is set in consideration of distribution.

  Of the steam supplied to the fuel reformer via the injection nozzle 5, the remaining steam that has not been supplied to the CO conversion catalyst layer 12 and the CO removal catalyst layer 14 passes through the steam outlet nozzle 7. 9 is supplied. Specifically, the cross-sectional area of the steam outlet nozzle 7 is set so that the steam flow rate necessary for the reforming catalyst reaction of the reforming catalyst layer 9 is supplied to the reforming catalyst layer 9.

  The water vapor that has passed through the water vapor outlet nozzle 7 is mixed with the fuel supplied through the fuel nozzle 8 and introduced into the reforming catalyst layer 9 for steam reforming. The hydrogen-rich reformed gas reformed in the reforming catalyst layer 9 is extracted through the reforming catalyst layer reformed gas outlet nozzle 10, and then CO through the CO conversion catalyst layer reformed gas inlet nozzle 11. It is introduced into the shift catalyst layer 12.

  The reformed gas introduced into the CO shift catalyst layer 12 through the CO shift catalyst layer reformed gas inlet nozzle 11 is mixed with the steam supplied through the CO shift catalyst steam feed hole 17 to produce a CO shift reaction. To increase the hydrogen concentration. Next, the reformed gas that has moved to the alumina ball layer 13 is mixed with the air supplied via the CO selective oxidation reaction air nozzle 15, and then moves to the CO removal catalyst layer 14.

  The reformed gas moved to the CO removal catalyst layer 14 is mixed with the steam supplied through the CO removal catalyst steam inlet hole 18, thereby improving the CO selectivity of the CO selective oxidation reaction, and hydrogen The efficiency of the fuel reformer can be improved by reducing the consumption and the input air flow rate. Further, the humidification effect makes it possible to improve the performance of the polymer electrolyte fuel cell on the downstream side of the fuel reformer.

  Next, the reformed gas is extracted out of the system through the CO removal catalyst layer reformed gas outlet nozzle 16.

  As shown in FIG. 1, in the fuel reformer of this embodiment, steam is supplied as a distribution means for distributing the steam supplied to the fuel reformer to the reforming catalyst layer 9 and the CO shift catalyst layer 12. A charging hole 17 and a water vapor outlet nozzle 7 are provided. Specifically, for example, of the steam supplied to the fuel reformer, the steam necessary for the reforming catalyst reaction in the reforming catalyst layer 9 is reformed by the steam outlet nozzle 7 constituting a part of the distribution means. Among the water vapor distributed to the layer 9 and supplied to the fuel reformer, at least a part of the water vapor not required for the reforming catalyst reaction in the reforming catalyst layer 9 constitutes a water vapor charging hole constituting a part of the distribution means 17 is distributed to the CO shift catalyst layer 12. Therefore, for example, as in the fuel reformer described in WO00 / 63114, the pressure loss of the entire fuel reformer is reduced as all the steam supplied to the fuel reformer is supplied to the reforming catalyst layer. Can be prevented from rising. In other words, of the steam supplied to the fuel reformer, even the steam that does not contribute to the reforming catalyst reaction in the reforming catalyst layer is supplied to the reforming catalyst layer and the pressure loss of the entire fuel reformer Can be prevented from rising.

  Furthermore, in the fuel reformer of this embodiment, as shown in FIG. 1, a CO removal catalyst layer 14 is further provided, and the reforming in the reforming catalyst layer 9 out of the steam supplied to the fuel reformer. Water vapor necessary for the catalytic reaction is distributed to the reforming catalyst layer 9 by the water vapor outlet nozzle 7 constituting a part of the distribution means, and CO conversion in the CO conversion catalyst layer 12 out of the water vapor supplied to the fuel reformer. The water vapor necessary for the catalytic reaction is distributed to the CO shift catalyst layer 12 through the water vapor introduction hole 17 constituting a part of the distribution means, and the CO removal in the CO removal catalyst layer 14 out of the water vapor supplied to the fuel reformer. The water vapor necessary for the catalytic reaction is distributed to the CO removal catalyst layer 14 by the water vapor introduction hole 18 constituting a part of the distribution means.

It is a schematic structure figure showing typically one embodiment of a fuel reformer of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Burner 2 Furnace 3 Combustion gas flow path 4 Exhaust gas nozzle 5 Input nozzle 6 Steam flow path 7 Steam outlet nozzle 8 Fuel nozzle 9 Reforming catalyst layer 10 Reforming catalyst layer reformed gas outlet nozzle 11 CO shift catalyst layer reformed gas inlet Nozzle 12 CO shift catalyst layer 13 Alumina ball layer 14 CO removal catalyst layer 15 Air injection nozzle 16 CO removal catalyst layer reformed gas outlet nozzle 17 Water vapor input hole 18 Water vapor input hole 19 Heat insulation material

Claims (2)

Comprising a reforming catalyst layer and a CO shift catalyst layer ;
In a multi-cylinder fuel reformer in which a steam channel is disposed outside a combustion gas channel, and a CO removal catalyst layer and the CO shift catalyst layer are disposed outside the steam channel ,
Distributing means for distributing the steam supplied to the fuel reformer to the reforming catalyst layer and the CO conversion catalyst layer ,
Forming a plurality of CO removal catalyst steam input holes in a partition tube between the steam flow path and the CO removal catalyst layer;
A fuel reformer , wherein a plurality of steam inlet holes for a CO shift catalyst are formed in a partition cylinder between the steam flow path and the CO shift catalyst layer . Arranging the plurality of CO removal catalyst steam introduction holes equally in the circumferential direction and the central axis direction of the fuel reformer;
2. The fuel reformer according to claim 1, wherein the plurality of steam inlet holes for the CO conversion catalyst are evenly arranged in a circumferential direction and a central axis direction of the fuel reformer.

Images