JP2005044709A - Hydrogen-containing gas generating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small hydrogen-containing gas generating device capable of highly efficiently manufacturing a hydrogen-containing gas under lower temperatures, and capable of stably supplying hydrogen for a long period of time. <P>SOLUTION: In this hydrogen-containing gas generating device, its reformer 2 is equipped with a tubular body 2b, a catalyst layer 2c comprising a reforming catalyst filled in the tubular body 2b to reform desulfurized LP gas and steam flowing in from the inlet 2a of the tubular body 2b to H2, CO, and CO2 by reforming reaction, a membrane tube 2d to extract the hydrogen-containing gas by selectively transmitting H2 among H2, CO, and CO2 obtained after the reforming reaction, and a wire net 2i to separate the membrane tube 2d from the catalyst layer 2c by 1 mm or less. In addition, in this hydrogen-containing gas generating device, the size between the inside perimeter of the tubular body 2b and the periphery of the membrane tube 2d is set at 13.5 mm or less, and a large ring plate 2e brought into contact with the inner peripheral surface of the tubular body 2b and separated from the wire net 2i by a prescribed space, and a small ring plate 2f separated from the inside perimetral surface of the tubular body 2b and brought into contact with the wire net 2i are alternatively disposed in the catalyst layer 2c. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hydrogen-containing gas generation device, and more particularly to a hydrogen-containing gas generation device that uses a LP gas as a raw fuel gas to produce a hydrogen-rich hydrogen-containing gas that serves as fuel for a fuel cell. .

  As a hydrogen-containing gas generating apparatus using LP gas as a raw fuel gas, for example, one having a configuration described later is known. Hereinafter, an outline of the hydrogen-containing gas generation device according to the conventional example 1 will be described with reference to FIG. 6 of a schematic configuration diagram of a fuel cell system.

The hydrogen-containing gas generating device P according to the conventional example 1 is provided in the fuel cell system 100, and reforming treatment is performed by mixing the LP gas supplied as the raw fuel gas from the LP gas cylinder 40 with water vapor so as to reduce the CO concentration. It is configured to produce a low (eg, 10 ppm or less) hydrogen-rich hydrogen-containing gas. The hydrogen-containing gas generated by the hydrogen-containing gas generator P is supplied to the fuel electrode 60 of the fuel cell G. On the other hand, the fuel cell G is a solid polymer type having a polymer membrane as an electrolyte 61, hydrogen in a hydrogen-containing gas supplied from the hydrogen-containing gas generator P to the fuel electrode 60, and an oxygen electrode 62 from the blower 57. The power is generated by an electrochemical reaction with oxygen in the reaction air supplied to the air. The hydrogen-containing gas generator P includes a desulfurizer 51 that desulfurizes LP gas supplied from the LP gas cylinder 40 through a flow path 77, and a steam generator 56 that generates steam by heating the supplied water. Then, the desulfurization raw fuel gas heated by the combustor 52a which is a reformer heating means and supplied from the desulfurizer 51 is reformed into a gas containing H ₂ and CO by using the steam generated by the steam generator 56. A reformer 52 that converts the CO in the reforming process gas supplied from the reformer 52 to CO ₂ using steam, and a CO converter 53 that converts the CO gas into CO ₂ using steam. Control equipped with a CO selective oxidation reactor 54 that performs selective oxidation treatment by selectively oxidizing CO in the supplied shift treatment gas, and operating condition setting means 81 for controlling the operating conditions of the generator P, etc. Part And it is configured from 0 Metropolitan.

The flow path 77 is provided with an adjustment valve 71 for adjusting the flow rate, and a thermal mass flow meter 74 for measuring the mass flow rate of the LP gas is provided downstream of the adjustment valve 71. The adjusting valve 71 is adjusted by the control unit 80 so that the power output of the fuel cell G follows the power load. The mass flow rate of LP gas measured by the thermal mass flow meter 74 is the component ratio of propane and butane in LP gas supplied to the desulfurizer 51 and the like as the remaining amount of LP gas in the LP gas cylinder decreases. Even if is changed, the carbon amount and the heat generation amount of LP gas are made proportional to a substantially constant heat generation amount.
The water supplied to the steam generator 56 is also adjusted by the adjustment valve 73 controlled by the control unit 80 so that the steam / carbon ratio of the steam supplied to the reformer 52 becomes a predetermined preferable value. . Further, a mixed gas of off gas discharged from the fuel electrode 60 of the fuel cell G and LP gas of the LP gas cylinder is supplied to the combustor 52a. The flow rate of the mixed gas is adjusted by an adjustment valve 72 controlled by the control unit 80 so as to be proportional to the carbon amount and the calorific value of the LP gas in a substantially constant calorific value. In other words, the generation device P according to this conventional example enables continuous operation even if the ratio of propane and butane in the LP gas changes as the remaining amount of the LP gas cylinder decreases. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 2003-146609

Further, a hydrogen gas separator (membrane) having a porous support capable of invading gas molecules and a gas separation membrane (coating) made of palladium or palladium alloy coated with the support and capable of dissolving hydrogen gas. There is a fuel cell system using a tube. In this fuel cell system, hydrogen is generated by a reforming reaction of a fuel such as methane or methanol and steam with the hydrogen gas separator (membrane tube), and the generated hydrogen is supplied to the fuel cell.
As a material constituting the support, ceramics such as carbon and porous glass are used in addition to ceramics such as alumina, silica, silica-alumina, mullite, cordierite, and zirconia (see, for example, Patent Document 2). ).
Japanese Patent Laid-Open No. 7-57758

The hydrogen-containing gas generator according to the above conventional example is extremely useful and considered to be excellent as such. However, the hydrogen-containing gas generator according to this conventional example is assumed to be large, and is considered to be insufficient for application to a fuel cell system in which downsizing and cost reduction are aimed. That is, in order to reduce the size and cost of the fuel cell system, it is indispensable to realize a small hydrogen-containing gas generator that can generate a hydrogen-containing gas at a lower temperature with high efficiency. By realizing such a hydrogen-containing gas generation device, a small and low-cost fuel cell system is realized, which can be used at home, for example, and has excellent thermal efficiency (about 80%), thus saving energy. It will be possible to greatly contribute to the prevention of global warming.

  Further, the palladium alloy coating on the membrane tube deteriorates the hydrogen permeation function with which other substances such as the reforming catalyst are in direct contact, and the hydrogen generation efficiency is reduced. However, in the above conventional example, there is no disclosure relating to prevention of deterioration of the hydrogen permeation function by direct contact with a reforming catalyst etc. of the palladium alloy film, and how to maintain the hydrogen permeation function of the palladium alloy film of the membrane tube. Is a big issue.

  Accordingly, an object of the present invention is to provide a small hydrogen-containing gas generator that can efficiently generate hydrogen-containing gas at a lower temperature and that can stably supply hydrogen over a long period of time. That is.

The present invention has been made in view of the above circumstances. Therefore, in order to solve the above problems, the configuration employed by the hydrogen-containing gas generation device (1) according to claim 1 of the present invention is a heating means. (1b) is provided with a reformer (2) that recovers the hydrogen-containing gas from the desulfurized LP gas and water vapor that is heated and supplied to the fuel cell (9). 2) is a cylinder (2b) having an inlet (2a) for LP gas and water vapor after desulfurization, and this cylinder (2b) is filled with water gas reaction and shift reaction between LP gas and water vapor. (hereinafter together referred to as reforming reaction) catalyst layer comprising a granular reforming catalyst is reacted with H ₂ and CO and CO ₂ by the (2c), H of the H ₂ and CO and CO ₂ after the reforming reaction covering the membrane _{tube 2} selectively transmits to recover a hydrogen-containing gas and (2d), the outer periphery of the membrane tubes (2d), the surface portion A metal mesh (2i) that separates the pipe (2d) from the catalyst layer (2c) with an interval of 1 mm or less, and a counterflow inlet (2a) side of the cylindrical body (2b). It comprises an outlet (2h) through which gas flows out to the fuel cell (9), and the dimension between the inner periphery of the cylinder (2b) and the outer periphery of the membrane tube (2d) is set to 13.5 mm or less. Along with the catalyst layer (2c), a large ring plate (2e) in contact with the inner peripheral surface of the cylindrical body (2b) and spaced apart from the wire mesh (2i), and an inner surface of the cylindrical body (2b) A small ring plate (2f) that is in contact with the metal mesh (2i) at a predetermined interval from the peripheral surface is alternately arranged.

The configuration adopted by the hydrogen-containing gas generator (1) according to claim 2 of the present invention recovers the hydrogen-containing gas from the desulfurized LP gas and water vapor that is heated by the heating means (1b) and supplied. A reformer (2) for supplying the fuel cell (9) is provided, the reformer (2) includes a cylinder (2b) having an inlet (2a) for LP gas and water vapor after desulfurization. , A catalyst layer (2c) comprising a granular reforming catalyst filled in the cylinder (2b) and reforming LP gas and water vapor into H ₂ , CO and CO ₂ , and H after the reforming reaction _2. A membrane tube (2d) that selectively permeates H ₂ out of CO, CO ₂ and recovers a hydrogen-containing gas, covers an outer periphery of the membrane tube (2d), and the membrane tube (2d) is used as the catalyst. A metal mesh (2i) that is separated from the layer (2c) by a distance of 1 mm or less and a counter flow inlet (2a) side of the cylindrical body (2b), and the recovered hydrogen-containing gas is supplied to the fuel cell (9). It from the outlet and (2h) to out, dimension between the outer periphery of the inner periphery and the membrane tube of the cylindrical body (2b) (2d) is characterized in that formed by set below 8 mm.

According to a third aspect of the present invention, there is provided a hydrogen-containing gas generating device according to claim 1 wherein the wire-containing gas generating device (1) according to any one of the first and second aspects is configured such that the wire mesh (2i). In order to prevent deterioration of the hydrogen permeation function of the palladium alloy film formed on the surface of the membrane tube (2d), it is manufactured from a wire made of stainless steel having an oxide film formed on the surface. It is what.

In the hydrogen-containing gas generator according to claim 1 of the present invention, the dimension between the inner periphery of the cylinder of the reformer heated by the heating means and the outer periphery of the membrane tube is 13.5 mm or less and the flow path is Although wide, the desulfurized LP gas and water vapor that flow into the cylinder from the inlet are formed on the inside of the large ring plate and the outside of the small ring plate that are alternately arranged in the catalyst layer of the granular reforming catalyst. The membrane tube can be brought into contact by changing the direction of the ring-shaped flow path. In the hydrogen-containing gas generator according to claim 2 of the present invention, the dimension between the inner periphery of the reformer cylinder heated by the heating means and the outer periphery of the membrane tube is 8 mm or less, and the flow path is Since it is narrow, LP gas and water vapor after desulfurization flowing into the cylinder from the inlet can be brought into contact with the membrane tube while passing through the catalyst layer of the granular reforming catalyst.

Therefore, according to the hydrogen-containing gas generator according to claim 1 or 2 of the present invention, the LP gas and water vapor after desulfurization are surely brought into contact with the surface of the reforming catalyst, so that the H _{2 is} effectively removed by the reforming reaction. And reformed to CO and CO ₂ . The membrane tube is separated from the catalyst layer at intervals of 1 mm or less by a metal mesh covering the outer periphery of the membrane tube. When H ₂ , CO, and CO ₂ flow inside the large ring plate, Since it reliably contacts the surface of the membrane tube through the mesh, H ₂ can be efficiently recovered by this membrane tube. Further, as described above, the outer periphery of the membrane tube is covered with a metal mesh, so that the reforming catalyst does not directly contact the surface of the membrane tube, and the H ₂ permeation function on the surface of the membrane tube does not deteriorate. Thus, H ₂ can be stably supplied to the fuel cell over a long period of time. Furthermore, as described above, H ₂ can be efficiently recovered by the membrane tube, and the membrane tube can be reduced in size. Therefore, the reformer can be reduced in size, and the hydrogen-containing gas generator can be reduced in size. Can be. On the other hand, since H ₂ is permeated through the membrane tube and effectively recovered and the reforming of LP gas and water vapor is promoted, LP gas and water vapor can be reformed at a lower temperature. Therefore, since the hydrogen-containing gas generator can be manufactured from an inexpensive material, it is possible to reduce the cost of the hydrogen-containing gas generator.

According to the hydrogen-containing gas generating apparatus according to claim 3 of the present invention, the wire mesh is provided with an oxide film on the surface in order to prevent deterioration of the hydrogen permeation function of the palladium alloy film formed on the surface of the membrane tube. Manufactured by a wire rod made of formed stainless steel. Therefore, the metal surface of the membrane tube does not directly contact the surface of the membrane tube, and the H ₂ permeation function of the surface of the membrane tube does not deteriorate. stably it can continue to supply of H ₂ Te.

Hereinafter, a hydrogen-containing gas generation apparatus according to Embodiment 1 of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a system diagram of a fuel cell system provided with a hydrogen-containing gas generator of the present invention, and FIG. 2 is a schematic cross-sectional view of a reformer of the hydrogen-containing gas generator.

First, the configuration of a fuel cell system provided with the hydrogen-containing gas generator of the present invention will be described with reference to FIG. The code | symbol 1 shown in FIG. 1 is a hydrogen containing gas production | generation apparatus. This hydrogen-containing gas generator 1 includes a housing 1a having a refractory disposed on the inner periphery thereof, and a cylindrical reformer 2 described later is accommodated vertically in the center thereof. Inside the housing 1a and on the lower side, a heating device 1b, which is a heating means provided with a burner 1c that encloses the entire reformer 2 and receives LP gas supplied from an LP gas cylinder (not shown), is disposed. The reformer 2 is configured to be heated to 600 ° C. by the heating device 1b. Furthermore, it is a pipe formed in a coil shape surrounding the top of the reformer 2 inside the housing 1a, and the heat of the combustion exhaust gas discharged from the heating device 1b into the housing 1a. Thus, an evaporator 1d is provided that evaporates the supplied water to produce water vapor. And it is comprised so that the combustion exhaust gas in the housing 1a may be discharge | released in air | atmosphere from the exhaust port 1f provided in the lower side part of this housing 1a.

An LP gas supply line 3 in which a desulfurizer 3 a is interposed from the LP gas cylinder communicates with an inflow port 2 a provided on the top end surface of the reformer 2. Further, in the vicinity of the connection portion from the evaporator 1d to the inlet 2a of the LP gas supply pipe 3, a water vapor supply pipe 1e for mixing water vapor into the LP gas flowing through the LP gas supply pipe 3 communicates. Yes. The burner 1c of the heating device 1b communicates with a fuel supply line 4 branched from between the LP gas cylinder of the LP gas supply line 3 and the desulfurizer 3a. Further, an auxiliary fuel supply line 6 passing through the heat exchanger 5 communicates from the lower part of the reformer 2 to the burner 1c, and is discharged from the reformer 2 through the auxiliary fuel supply line 6. The off gas (containing H ₂ and CO) is also supplied as auxiliary fuel.

The hydrogen-containing gas reformed and recovered by the reformer 2 heated the CO methanation 7 that removes CO contained in the hydrogen-containing gas that lowers the output of the fuel cell 9 by the methanation reaction. Thereafter, a hydrogen supply line 8 passing through the heat exchanger 5 and the CO methanation 7 communicates with the fuel cell 9. As a result, a hydrogen-containing gas having an H ₂ concentration of 99.9% by volume is supplied to the fuel cell 9. The water generated by the fuel cell 9 is stored in a water storage tank 10. A water supply line 11 is connected from the water storage tank 10 to the evaporator 1d via the heat exchanger 5, and the water stored in the water storage tank 10 has an output of about 1 to 2 w. While being pumped up with a pump, it is heated and supplied to the evaporator 1d.

As shown in FIG. 2 (only four ring plates are schematically shown), the reformer 2 is heated by a heating device 1b and from an inlet 2a through which an LP gas supply line 3 communicates. A cylinder 2b into which LP gas and water vapor after desulfurization flows is provided. The cylindrical body 2b has a granular form in which LP gas and water vapor are reacted with H ₂ , CO, and CO ₂ by a water gas reaction and a shift reaction (hereinafter, these reactions are collectively referred to as a reforming reaction). For example, the catalyst layer 2c is formed by filling a reforming catalyst made of ruthenium supported on porous alumina. The catalyst layer 2c is a membrane tube 2d which selectively transmitting of H ₂ recovering a hydrogen-containing gas of H ₂ and CO and CO ₂ after the reforming reaction is embedded vertically.

The membrane tube 2d is composed of a porous ceramic tube and a palladium alloy (Pd-Ag) film electrolessly plated on the surface of the porous ceramic tube, and the membrane tube 2d is composed of the membrane tube 2d. Is separated from the catalyst layer 2c by a metal mesh 2i covering the outer periphery of the metal, and the distance between them is set to 1 mm or less. In this case, a wire mesh 2i having a thickness of 1 mm or less, for example, a 0.7 mm or 0.5 mm thickness metal mesh 2i is used. The metal mesh 2i is made of a stainless steel wire having an oxide film formed on the surface thereof. The lower part of the membrane tube 2d is connected to a metal fitting 2g having an outlet 2h to which the hydrogen supply conduit 8 is connected at the lower end through a seal ring made of graphite. As the material of the porous ceramic tube, alumina, silica, silica-alumina, mullite, cordierite, zirconia and the like can be adopted as in the case of the conventional example 2. A porous tube manufactured by a sintering method can also be employed.

The dimension between the inner periphery of the cylinder 2b and the outer periphery of the membrane tube 2d is set to 13.5 mm. In this case, the flow path through which the LP gas and water vapor flow is wide, and most of the LP gas and water vapor flows through a portion of the wire mesh where resistance is low, that is, the outer peripheral portion of the membrane tube 2d, which is 0.5 mm, and the catalyst layer 2c. The amount of LP gas and water vapor flowing through the gas decreases and the reforming efficiency decreases, and the amount of H ₂ permeated through the membrane tube 2d may decrease. Therefore, three large ring plates 2e and two small ring plates 2f are provided on the catalyst layer 2c in order to ensure that LP gas and water vapor flow into the catalyst layer 2c and to contact the palladium alloy coating on the surface of the membrane tube 2d. Were alternately arranged at predetermined intervals (35 mm intervals). The large ring plate 2e has an outer diameter in contact with the inner peripheral surface of the cylindrical body 2b, and has an inner diameter that is spaced apart from the wire mesh 2i. The small ring plate 2f The cylindrical body 2b has an outer diameter that is spaced from the inner peripheral surface of the cylindrical body 2b and an inner diameter that is in contact with the wire mesh 2i. The number of the large ring plate 2e and the small ring plate 2f should be changed according to the length of the membrane tube 2d and cannot be determined uniquely.

Hereinafter, the operation mode of the hydrogen-containing gas generation device 1 according to Embodiment 1 of the present invention will be described. That is, in the hydrogen-containing gas generator 1 according to Embodiment 1 of the present invention, the dimension between the inner periphery of the cylindrical body 2b of the reformer 2 and the membrane tube 2d is 13.5 mm and the flow path is wide. However, the flow direction of the desulfurized LP gas and water vapor flowing into the cylinder 2b from the inlet 2a is set so that the inside of the large ring plate 2e and the outside of the small ring plate 2f arranged alternately in the catalyst layer 2c. The membrane tube 2d can be brought into contact with the membrane tube 2d while being reformed by changing the direction of the ring-shaped channel formed in the above.

Therefore, according to the hydrogen-containing gas generation device 1 according to Embodiment 1 of the present invention, the LP gas and water vapor after desulfurization are surely in contact with the surface of the reforming catalyst of the catalyst layer 2c. reformed into H ₂ and CO and CO _2. The outer periphery of the membrane tube 2d is covered with a metal mesh 2i. When H ₂ , CO, and CO ₂ flow through the ring-shaped flow path inside the large ring plate 2e, the mesh 2i is connected through the mesh of the metal mesh 2i. Since it reliably contacts the palladium alloy coating formed on the surface of the membrane tube 2d, the membrane tube 2d can efficiently recover H ₂ . Further, as described above, the outer periphery of the membrane tube 2d is covered with the wire mesh 2i, and the reforming catalyst does not directly contact the surface of the membrane tube 2d, and the palladium alloy formed on the surface of the membrane tube 2d. Since the H ₂ permeation function of the coating does not deteriorate, H ₂ can be stably supplied to the fuel cell 9 over a long period of time.

Further, as described above, since the H ₂ can be efficiently recovered by the membrane tube 2d, the membrane tube 2d can be reduced in size. Therefore, the reformer 2 can be reduced in size, and consequently the hydrogen-containing gas generator 1 can be reduced in size. On the other hand, since H ₂ is permeated through the membrane tube 2d and effectively recovered and the reforming of LP gas and water vapor is promoted, the LP gas and water vapor can be reformed at a lower temperature (600 ° C.). Therefore, since the hydrogen-containing gas generating device 1 can be manufactured from an inexpensive material, the hydrogen-containing gas generating device 1 can be reduced in cost. Further, the wire mesh 2i is manufactured by a wire made of stainless steel having an oxide film formed on the surface thereof in order to prevent deterioration of the hydrogen permeation function of the palladium alloy film formed on the surface of the membrane tube 2d. . Therefore, the metal of the wire mesh 2i is not in direct contact with the surface of the membrane tube 2d, and the H ₂ permeation function of the palladium alloy coating is not deteriorated. Can continue to be supplied with H ₂ .

Next, a hydrogen-containing gas generation device according to Embodiment 2 of the present invention will be described with reference to FIG. 3 of a schematic cross-sectional view of a reformer of the hydrogen-containing gas generation device. However, the difference between the present embodiment 2 and the above embodiment is the difference in the configuration of the reformer of the hydrogen-containing gas generator, and the rest of the configuration is exactly the same, so only the differences will be described.

The reformer 2 of the hydrogen-containing gas generation device according to the second embodiment is configured as shown in FIG. That is, the inside of the cylindrical body 2b, the catalyst layer 2c is formed by reforming catalyst particulate which reforming reaction of LP gas and steam to H ₂ and CO and CO ₂ is filled. The catalyst layer 2c includes a porous ceramic tube that selectively permeates H ₂ out of H ₂ , CO, and CO ₂ after the reforming reaction to recover a hydrogen-containing gas, and the porous ceramic tube. A membrane tube 2d, which is electrolessly plated on the surface and is made of a palladium alloy coating having a thickness of 3 μm, is embedded vertically. As in the case of the first embodiment, the membrane tube 2d is separated from the catalyst layer 2c by 1 mm or less by a metal mesh 2i covering the membrane tube 2d. And the lower part of this membrane pipe 2d is connected to the metal fitting 2g which has the outflow port 2h to which the hydrogen supply pipe line 8 is connected to the lower end through the seal ring which consists of graphite. The dimension between the inner periphery of the cylinder 2b and the outer periphery of the membrane tube 2d is set to 8 mm or less. In this case, since the dimension between the inner periphery of the cylinder 2b of the reformer 2 and the outer periphery of the membrane tube 2d is 8 mm or less and the flow path is narrow, the desulfurized LP gas flowing into the cylinder 2b from the inlet 2a. And water vapor can be brought into contact with the surface of the membrane tube 2d while being reformed through the catalyst layer 2c of the granular reforming catalyst. Therefore, in the case of this form 2, unlike the said form 1, the ring layer for converting the flow direction of LP gas and water vapor | steam is not provided in the catalyst layer 2c.

Hereinafter, the operation mode of the hydrogen-containing gas generation device according to Embodiment 2 of the present invention will be described. That is, since the dimension between the inner periphery of the cylinder 2b of the reformer 2 and the outer periphery of the membrane tube 2d is 8 mm or less and the flow path is narrow, the desulfurized LP gas flowing into the cylinder 2b from the inlet 2a The water vapor passes through the catalyst layer 2c of the granular reforming catalyst and contacts the surface of the membrane tube 2d. Therefore, according to the hydrogen-containing gas generator 1 according to Embodiment 2 of the present invention, the LP gas and water vapor after desulfurization are surely in contact with the surface of the reforming catalyst of the catalyst layer 2c. reformed into H ₂ and CO and CO _2. Since the wire mesh 2i covering the surface of the membrane tube 2d is made of a stainless steel wire having an oxide film formed on the surface thereof, the hydrogen-containing gas generating device according to aspect 2 of the present invention is the above aspect. 1 is obtained. In the case of the form 2 according to the present invention, as described above, the dimension between the inner periphery of the cylinder 2b and the outer periphery of the membrane tube 2d is 8 mm or less. Therefore, when the outer diameter of the membrane tube 2d is the same as that of the membrane tube of Form 1, the cylindrical body 2b is thin, so that the hydrogen-containing gas generator can be made smaller than in the case of Embodiment 1 described above.

In the following, an embodiment of the present invention relates to a prototype, and FIG. 4 is a schematic cross-sectional view of a reformer of a hydrogen-containing gas generator, FIGS. This will be described with reference to FIG. 5 showing the relationship between the thickness of the catalyst layer and the hydrogen permeation amount, with the horizontal axis representing the reforming load (%) with 1 kW being 100%.

First, the process of achieving the hydrogen-containing gas generator according to the present invention will be described with reference to FIGS. The inventors have thought that a membrane tube may be used to realize a small hydrogen-containing gas generating device that can generate a hydrogen-containing gas at a lower temperature with high efficiency. That is, since H ₂ can be efficiently recovered, the reformer including the membrane tube can be reduced in size, and as a result, the hydrogen-containing gas generator can be reduced in size.
In addition, it is possible to use low-temperature materials at low temperatures, so it is possible to reduce the cost of the hydrogen-containing gas generation device, and in addition, the membrane tube can be used stably for a long time. is there.

Therefore, four types of reformers 2 having the configurations shown in FIGS. First, the reformer 2 according to the prototype 1 shown in FIG. 4 includes a cylindrical body 2b having an inflow port 2a for LP gas and water vapor after desulfurization. This is cylindrical body 2b, the catalyst layer 2c made of granular reforming catalyst for reforming reaction of LP gas and steam to H ₂ and CO and CO ₂ are formed. Embedded in the catalyst layer 2c is a membrane tube 2d that selectively permeates H ₂ out of H ₂ , CO, and CO ₂ after the reforming reaction to recover a hydrogen-rich hydrogen-containing gas. The membrane tube 2d has a palladium alloy (Pd-Ag) film having a thickness of 5 μm formed by electroless plating on a porous ceramic tube having an outer diameter of 29 mmφ, and the membrane tube 2d is a wire mesh 2i covering the membrane tube 2d. Is separated from the catalyst layer 2c by 1 mm or less. The dimension between the outer periphery of the membrane tube 2d and the inner periphery of the cylindrical body 2b is set to 13.5 mm, and the vertical length of the transmission surface of the membrane tube 2d is set to 250 mm. The hydrogen-rich hydrogen-containing gas that passes through the membrane tube 2d and is collected inside is discharged from an outlet 2h provided in the lower portion of the cylindrical body 2b.

The reformer 2 according to the prototype 2 shown in FIG. 2 is provided with conversion means for converting the flow direction of LP gas and water vapor after desulfurization flowing from the inlet 2a into the configuration according to the prototype 1 described above. It is.
Specifically, the catalyst layer 2c has three large ring plates 2e that are in contact with the inner peripheral surface of the cylindrical body 2b and are spaced apart from the wire mesh 2i by a predetermined distance from the inner peripheral surface of the cylindrical body 2b. And three small ring plates 2f that are in contact with the wire mesh 2i are alternately arranged at a predetermined interval.
That is, as shown in FIG. 2, LP gas and water vapor are alternately changed in the direction of the surface of the membrane tube 2d and the direction of the inner peripheral surface of the cylindrical body 2b, so that the reforming catalyst is always between the ring plates. And it is comprised so that a membrane surface may be touched.

The reformer 2 according to the prototype 3 shown in FIG. 3 includes a cylindrical body 2b having an inlet 2a for LP gas and water vapor after desulfurization at the upper part. This is cylindrical body 2b, the catalyst layer 2c made of granular reforming catalyst for reforming reaction of LP gas and steam to H ₂ and CO and CO ₂ are formed.
The catalyst layer 2c is embedded with a membrane tube 2d having an outer diameter of 29 mmφ and selectively permeating H ₂ out of H ₂ , CO, and CO ₂ after the reforming reaction to recover a hydrogen-containing gas. Has been. The membrane tube 2d is separated from the catalyst layer 2c by 1 mm or less by a wire mesh 2i covering the membrane tube 2d. The dimension between the outer periphery of the membrane tube 2d and the inner periphery of the cylindrical body 2b is set to 8 mm, and the vertical length of the transmission surface of the membrane tube 2d is set to 280 mm. The hydrogen-rich hydrogen-containing gas recovered through the membrane tube 2d is configured to be discharged from an outlet 2h provided at the lower portion of the cylindrical body 2b.

  Furthermore, the reformer 2 according to the prototype 4 has the same configuration as that of the reformer 2 according to the prototype 3 shown in FIG. 3, and is between the outer periphery of the membrane tube 2d and the inner periphery of the cylindrical body 2b. A reformer 2 having a size of 5 mm was also prepared.

47 to 79 (N liter / h) of LP gas was supplied to each reformer, and the catalyst inlet temperature was 480 ° C., the catalyst layer outlet temperature was 600 ° C., the pressure was 4,4 atm (≈0.43 MPa, LP gas cylinder The pressure was achieved simply by supplying LP gas from the gas.), And the test was conducted at S / C = 3. The result shows the relationship between the catalyst layer thickness and the hydrogen permeation amount, with the hydrogen permeation amount (N liter / h) on the vertical axis and the reforming load (%) on the horizontal axis with 1 kW as 100%. This is as shown in FIG. In the figure, the white and black circles indicate the reformer according to prototype 2, the white and black triangles indicate the reformer according to prototype 3, and the white and black squares indicate prototype 4. The white circles, white triangles, and white square marks indicate calculated values, and the black circles, black triangles, and black square marks indicate actually measured values.
However, in the case of the reformer 2 according to the prototype 1, the actual measurement value is about 50% of the calculated value and the hydrogen permeation amount is small, and thus the illustration is omitted.

In the reformer 2 according to the prototype 2, as indicated by a circle in FIG. 5, the hydrogen recovery rate is about 98% of the calculated value, and almost 100% can be recovered. It can be seen that Incidentally, the composition of the reformed gas by the reforming catalyst of the reformer 2 according to the prototype 2 obtained by gas analysis is as follows: H ₂ ; 72.6% by volume, CO; 4.4% by volume, CH ₄ ; 3 0.8% by volume, CO ₂ ; 19.2% by volume.

In the reformer 2 according to the prototype 3, as indicated by a triangular mark in FIG. 5, about 85% of the calculated value is recovered, and it can be seen that the reformer 2 has a function that can be sufficiently put to practical use. Incidentally, in an example of the test of the reformer 2 according to the prototype 3, the amount of the hydrogen-containing gas permeated through the membrane 2d is 185 N liter / h, and the composition of the hydrogen-containing gas obtained by gas analysis is H ₂ ; 99 .57% by volume, CO; 0.18% by volume, CH ₄ ; 0.18% by volume, CO ₂ ; 0.20% by volume.
The off-gas amount was 310 N liter / h, and the off-gas composition determined by gas analysis was H ₂ ; 52.98% by volume, CO; 9.78% by volume, CH ₄ ; 7.54% by volume, CO _2. 29.70% by volume.

  In the reformer 2 according to the prototype 4, as shown by the square marks in FIG. 5, the hydrogen recovery rate is 96% or more of the calculated value, and almost 100% can be recovered. You can see that This indicates that the hydrogen extraction effect of the reformed gas membrane tube 2d that has undergone reforming reaction with the reforming catalyst at a position exceeding 8 mm from the membrane tube 2d is low. Naturally, as the reforming catalyst is brought closer to the membrane tube 2d, the hydrogen abstraction effect is improved. However, if the reforming catalyst is disposed only from this point of view, in order to secure the necessary amount of the reforming catalyst, the membrane is secured. The surface area of the tube 2b must be increased. Therefore, as a result, the hydrogen-containing gas generating apparatus becomes large, and it is concluded that it is preferable to dispose the reforming catalyst within the range of 8 mm from the membrane tube 2d to improve the hydrogen drawing effect. can do.

As well understood from the above examples, from the viewpoint of hydrogen-containing gas generation performance, the reformer 2 according to the prototype 2 is most preferable, but the reformer 2 according to the prototype 3 or 4 is most preferable. It can also be said that this is a configuration that can be practically used. By the way, although it tried also about the case where the separation dimension of a membrane pipe | tube and a catalyst layer exceeds 1 mm, since there is much gas flowing through the metal-mesh arrangement | positioning site | part with smaller flow-path resistance than a modification layer, it is hydrogen It has been confirmed that the amount of permeation is small. In the above, the case where LP gas is used as the raw fuel gas has been described as an example. However, LP gas is not particularly required, and other hydrocarbons can also be used.

It is a distribution diagram of a fuel cell system provided with the hydrogen content gas generating device of the present invention. FIG. 4 is a schematic cross-sectional view of a reformer of a hydrogen-containing gas generation device according to Embodiment 1 or Prototype 2 of the present invention. FIG. 4 is a schematic cross-sectional view of a reformer of a hydrogen-containing gas generation device according to the second embodiment or prototypes 3 and 4 of the present invention. FIG. 3 is a schematic cross-sectional view of a reformer of a hydrogen-containing gas generation device according to prototype 1 of the present invention. According to the embodiment of the present invention, the vertical axis represents the hydrogen permeation amount (N liter / h), and the horizontal axis represents the reforming load (%) where 1 kW is 100%, and the thickness of the catalyst layer and the hydrogen permeation are shown. It is quantity related explanatory drawing. It is a schematic block diagram of the fuel cell system which concerns on the prior art example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hydrogen-containing gas production | generation apparatus, 1a ... Housing, 1b ... Heating device (heating means), 1c ... Burner, 1d ... Evaporator, 1e ... Water vapor supply line, 1f ... Exhaust port (combustion exhaust gas)
2 ... reformer, 2a ... inlet, 2b ... cylinder, 2c ... catalyst layer, 2d ... membrane tube, 2e ... large ring plate, 2f ... small ring plate, 2g ... metal fitting, 2h ... outlet, 2i ... Wire mesh 3 ... LP gas supply line, 3a ... desulfurizer 4 ... fuel supply line 5 ... heat exchanger 6 ... auxiliary fuel supply line 7 ... CO methanation 8 ... hydrogen supply line 9 ... fuel cell 10 ... water storage tank 11 ... Water supply pipeline

Claims (3)

The reformer (2) is provided with a reformer (2) that is heated by the heating means (1b) and collects the hydrogen-containing gas from the desulfurized LP gas and water vapor that is supplied to the fuel cell (9). The vessel (2) has a cylindrical body (2b) having an inlet (2a) for LP gas and water vapor after desulfurization, and the cylindrical body (2b) is filled with LP gas and water vapor as H ₂ and CO. catalyst layer comprising a granular reforming catalyst for reforming reaction in CO ₂ (2c), and is transported to recover the hydrogen-containing gas of H ₂ of the H ₂ and CO and CO ₂ after the reforming reaction selectively transmit A membrane tube (2d), a wire mesh (2i) that covers the outer periphery of the membrane tube (2d) and isolates the membrane tube (2d) from the catalyst layer (2c) with an interval of 1 mm or less, and the cylindrical body (2b) is provided on the counter-flow inlet (2a) side, and includes an outlet (2h) through which the recovered hydrogen-containing gas flows out to the fuel cell (9), and the inner periphery of the cylindrical body (2b) and the membrane tube (2d) The dimension between the outer periphery is set to 13.5 mm or less, and the catalyst layer (2c) is in contact with the inner peripheral surface of the cylindrical body (2b) and is spaced apart from the wire mesh (2i) by a predetermined distance. The ring plate (2e) and the small ring plate (2f) in contact with the wire mesh (2i) at a predetermined interval from the inner peripheral surface of the cylindrical body (2b) are alternately arranged. A hydrogen-containing gas generator. The reformer (2) is provided with a reformer (2) that is heated by the heating means (1b) and collects the hydrogen-containing gas from the desulfurized LP gas and water vapor that is supplied to the fuel cell (9). The vessel (2) has a cylindrical body (2b) having an inlet (2a) for LP gas and water vapor after desulfurization, and the cylindrical body (2b) is filled with LP gas and water vapor as H ₂ and CO. catalyst layer comprising a granular reforming catalyst for reforming reaction in CO ₂ (2c), and is transported to recover the hydrogen-containing gas of H ₂ of the H ₂ and CO and CO ₂ after the reforming reaction selectively transmit A membrane tube (2d), a wire mesh (2i) that covers the outer periphery of the membrane tube (2d) and isolates the membrane tube (2d) from the catalyst layer (2c) with an interval of 1 mm or less, and the cylindrical body (2b) is provided on the counter-flow inlet (2a) side, and includes an outlet (2h) through which the recovered hydrogen-containing gas flows out to the fuel cell (9), and the inner periphery of the cylindrical body (2b) and the membrane tube (2d) Hydrogen-containing gas generating device dimensions characterized by comprising set 8mm or less between the outer.   The wire mesh (2i) is manufactured by a wire made of stainless steel having an oxide film formed on the surface in order to prevent deterioration of the hydrogen permeation function of the palladium alloy film formed on the surface of the membrane tube (2d). The hydrogen-containing gas generating device according to claim 1, wherein the hydrogen-containing gas generating device is a gas generator.

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