JP4799995B2 - Steam reformer - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a hydrocarbon-based raw material steam reformer, and more specifically, a hydrocarbon-based raw material steam having a reforming catalyst portion disposed in a double-cylinder gap formed by an outer tube and an inner tube or inside a single tube. It relates to a reformer.

  For example, in a steam reformer that supplies hydrogen to a polymer electrolyte fuel cell (hereinafter abbreviated as “PEFC” where appropriate), a plurality of catalysts such as a reforming catalyst, a CO shift catalyst, and a CO removal catalyst are used. Since the reforming catalyst is used at a high temperature of 600 ° C. or higher, for example, 700 ° C., when the reactors in which the catalysts are respectively arranged are arranged as separate bodies, piping, heat insulating materials, etc. for connecting the reactors are provided. It becomes necessary and the equipment configuration becomes complicated. Therefore, with the aim of simplifying and downsizing them, a steam reformer in which the respective reactors are integrated has been considered. The present inventors have developed such an integrated steam reformer (hereinafter referred to as “integrated steam reformer” as appropriate), and have continued to improve and improve it for practical use (Patent Documents) 1-5).

WO 00 / 63114A1 WO 02 / 098790A1 JP 2002-187705 A Japanese Patent Application No. 2005-1515 (filed on January 6, 2005) Japanese Patent Application No. 2005-49328 (filed on February 24, 2005)

  FIG. 1 shows an example of this as a longitudinal sectional view (WO 02/098790 A1). As shown in FIG. 1, the first cylindrical body 1, the second cylindrical body 2, and the third cylindrical body 3, whose diameters are sequentially increased, are arranged at the same center axis and spaced apart from each other. The fourth cylinder 4 having a diameter larger than that of the third cylinder 3 is arranged. In FIG. 1, the alternate long and short dash line indicates the central axis, and the arrow indicates the direction of the central axis, that is, the axial direction. A cylindrical heat transfer partition wall, that is, a radiation cylinder 5 having a diameter smaller than that of the first cylinder 1 is arranged inside the first cylinder 1, and a burner 6 is arranged in the radiation cylinder 5. ing. The burner 6 is disposed at the central shaft portion and is attached to the inside of the radiation tube 5 via an upper lid / burner mounting base 7.

  The radiation cylinder 5 is disposed with a gap between the lower end thereof and the bottom plate 8 of the first cylindrical body 1, and this gap and the gap between the radiation cylinder 5 and the first cylindrical body 1 connected to the gap are provided. An exhaust passage 9 for combustion exhaust gas from the burner 6 is formed. The bottom plate 8 is formed in a disc shape with a diameter corresponding to the diameter of the first cylindrical body 1. The exhaust passage 9 is connected to the exhaust port 11 of the combustion exhaust gas through the gap between the upper cover of the exhaust passage 9 (the upper cover and the lower surface of the burner mounting base 7) and the partition wall 10 (the upper cover of the preheating layer 14 to be described later). Exhaust gas is discharged from here.

  12 is a supply pipe for hydrocarbon-based raw material, that is, a raw material gas. In the space between the first cylindrical body 1 and the second cylindrical body 2, a preheating layer 14 is formed in the upper part, and a reforming is performed in the lower part following the preheating layer 14. A catalyst layer 16 is provided. A single round bar 15 is spirally arranged inside the preheating layer 14, thereby forming one continuous spiral gas passage inside the preheating layer 14. The reforming catalyst of the reforming catalyst layer 16 is supported at its lower end by a support 17 such as a perforated plate or a mesh body.

  The raw material gas supplied from the supply pipe 12 is mixed with water (water vapor) in the mixing unit 13 and then introduced into the reforming catalyst layer 16 through the preheating layer 14, and the hydrocarbon-based raw material in the mixed gas is lowered. While being reformed by steam. The reforming reaction in the reforming catalyst layer 16 is an endothermic reaction, and the reforming reaction proceeds by absorbing the combustion heat generated by the burner 6. That is, when the combustion gas in the burner 6 flows and passes through the exhaust passage 9 between the radiation cylinder 5 and the first cylindrical body 1, the heat of the combustion gas is absorbed by the reforming catalyst layer 16 and the reforming reaction is performed. Progresses.

  The lower end of the second cylinder 2 is disposed with a gap between the bottom plate 18 of the third cylinder 3, and a reformed gas flow path 19 is provided between the second cylinder 2 and the third cylinder 3. Is configured. The bottom plate 18 is formed in a disc shape with a diameter corresponding to the diameter of the third cylindrical body 3. The reformed gas is folded between the lower end of the second cylindrical body 2 and the bottom plate 18 of the third cylindrical body 3 and flows through the flow path 19 formed between the second cylindrical body 2 and the third cylindrical body 3. A fourth cylindrical body 4 having a diameter larger than that of the third cylindrical body 3 is disposed above the third cylindrical body 3, and a CO shift catalyst layer 22 is provided between the second cylindrical body 2 and the fourth cylindrical body 4. ing.

  A plate 20 (the portion corresponding to the diameter of the third cylinder 3 is occupied by the third cylinder 3 at the upper end of the third cylinder 3 and the lower end of the fourth cylinder 4, so a donut-shaped plate ) And a support plate 21 having a plurality of holes for gas circulation at intervals on the plate body 19 (the portion corresponding to the diameter of the second cylinder body 2 is occupied by the second cylinder body 2). , A donut-shaped support plate) is disposed. The CO shift catalyst layer 22 includes a support plate 21 and a support plate 23 having a plurality of holes for gas flow (the portion corresponding to the diameter of the second cylindrical body 2 is occupied by the second cylindrical body 2, so a donut-shaped support plate , The upper cover of the CO shift catalyst layer 22). The support plates 21 and 23 may be formed of a mesh body made of metal or the like. In this case, the mesh body of the mesh body serves as a gas flow hole. The reformed gas that has flowed through the flow path 19 is supplied to the CO conversion catalyst layer 22 through the holes of the support plate 21.

  As described above, the CO conversion catalyst layer 22 is provided between the second cylindrical body 2 and the fourth cylindrical body 4, and the cylindrical body 25 is disposed on the outer periphery of the fourth cylindrical body 4 with a gap therebetween. In between, the heat insulating material 24 is arrange | positioned. A heat transfer tube 27 connected to the water supply tube 26 is directly wound around the outer periphery of the cylindrical body 25 in a spiral shape. The heat transfer tube 27 functions as a cooling mechanism for indirectly cooling the CO shift catalyst layer 22. In the CO conversion catalyst layer 22, CO in the reformed gas is converted into carbon dioxide by the CO conversion reaction, and hydrogen is also generated.

  The heat insulating material 24 is wound to a thickness that can be uniformly maintained at an appropriate temperature without excessively reducing the temperature of the CO shift catalyst layer 22 by the cooling action of the heat transfer tube 27. The heat transfer pipe 27 has a function as a boiler for water (= process water) supplied from the water supply pipe 26 and is a single continuous path that continues from the water supply pipe 26, and thus occurs in a plurality of paths. Partial stagnation does not occur.

  A partition plate 28 having one communication hole 29 is provided above the support plate 23 at a predetermined interval, and CO removal air is supplied to the space between both plates through an air supply pipe 30. An annular passage 31 is provided above the partition plate 28. By using one communication hole 29 with a predetermined hole diameter, a predetermined passing speed is obtained when the reformed gas and the CO removing air pass through the communication hole 29, and the reformed gas is modified by turbulent flow during the passage. The quality gas and the air for removing CO can be mixed well. The CO removal catalyst layer 36 is disposed at intervals between the second cylinder 2, the cylinder 37 having a larger diameter, and the lower part and the upper part between the second cylinder 2 and the cylinder 37, respectively. A support plate 34 having a plurality of holes 35 (a portion corresponding to the diameter of the second cylindrical body 2 is occupied by the second cylindrical body 2), and a plurality of holes 39 for gas distribution. And a support plate 38 (a portion corresponding to the diameter of the second cylindrical body 2 is occupied by the second cylindrical body 2), and is provided in a space between the support plate 38 and the support plate 38.

  A plurality of holes 33 provided equally in the circumferential direction are provided in the lower portion of the cylindrical body 37. The annular passage 31 is a passage formed by the cylindrical body 25, the partition plate 28, the partition plate 32, and the cylindrical body 37, through the plurality of holes 33 and the plurality of holes 35 of the support plate 34. The reformed gas, which is in communication with the CO removal catalyst layer 36 and mixed with CO removal air, is introduced into the CO removal catalyst layer 36 through the plurality of holes 33 and 35. The CO removal catalyst layer 36 communicates with a reformed gas take-out pipe 40 through a gap between a partition plate 38 having a plurality of holes 39 serving as an upper lid and the partition wall 10. In addition, the CO removal catalyst layer 36 is surrounded by a cylindrical body 37, and a heat transfer tube 27 continuous from the heat transfer tube 27 on the outer periphery of the cylindrical body 25 is directly spirally wound around the outer periphery of the cylindrical body 37.

  The CO removal catalyst layer 36 is filled with a CO removal catalyst (= PROX catalyst), and a CO removal reaction is performed by the PROX catalyst to reduce the CO content in the reformed gas to the ppm unit. The reformed gas from which CO has been removed is discharged from a plurality of holes 39 provided in the partition plate 38 that is the upper lid, and is taken out from the reformed gas take-out pipe 40 through the gap between the partition plate 38 and the partition wall 10. It is. A heat insulating material 41 is disposed on the outer peripheral portion including the third cylindrical body 3, the cylindrical body 25, and the cylindrical body 37 to prevent heat from being dissipated to the outside.

  By the way, for example, in the steam reformer configured as described above, the reforming catalyst layer 16 is formed by laminating the reforming catalyst between the first cylindrical body 1, that is, the inner tube 1, and the second cylindrical body 2, that is, the outer tube 2. It is comprised by arranging in. A mixed gas of hydrocarbon-based raw material and water vapor is introduced into the reforming catalyst layer 16 from the upper end or lower end of the reforming catalyst layer 16, and discharged from the lower end or upper end as a hydrogen mixed gas, respectively.

  In this specification, the inner tube 1, the outer tube 2 and the reforming catalyst layer 16 (the reforming catalyst layer 16 is configured by filling the gap between the inner tube 1 and the outer tube 2 with the reforming catalyst). The part that contains it is called the reforming part or the reforming catalyst part. Further, in the reforming catalyst layer 16 or the reforming section, the introduction side of the mixed gas of hydrocarbon-based raw material and steam is referred to as “upstream” or “upstream side”, and the end thereof is referred to as the upstream end. In the reforming catalyst layer 16 or the reforming section, the hydrogen-rich reformed gas outlet side is referred to as “downstream” or “downstream side”.

<Operation, observation, and discovery of problems with a steam reformer integrated with actual equipment>
When the steam reformer is used in a combined heat and power system using, for example, a household PEFC, it is necessary to start and stop frequently. The inventors of the present invention operate the steam reformer by repeatedly starting and stopping over a long period of time, and observe whether there is further improvement. As a result, it has been found that the reforming catalyst of the reforming section gradually deteriorates little by little from the upstream side of the reforming section. Further, it was found that the reforming catalyst settled down due to the repetition of the temperature rise and the temperature drop accompanying the start-stop, and the upstream of the reforming section was hollow.

<Investigation of the cause of problems in actual steam generators>
And the following facts were found as the cause of these problems. The hydrocarbon-based raw material contains a sulfur component. For example, city gas and petroleum gas contain sulfur compounds such as mercaptans, sulfides, or thiophenes as odorants at a level of several ppm. Since the sulfur compound (sulfur content) in the hydrocarbon-based raw material deteriorates the reforming catalyst, it is removed as much as possible by the desulfurizer. However, the removal of the sulfur compound is not complete and leaks slightly (ppb level or less). As a result, it has been found that the reforming catalyst in the reforming section is poisoned, and the reforming catalyst on the upstream side of the reforming section is more likely to decrease in activity.
Further, it was found that the fact that the upstream of the reforming part becomes hollow due to the temperature change accompanying the start-stop is due to the high packing density of the reforming catalyst and the corresponding sedimentation.

  Such reforming of the reforming unit upstream side due to the sulfur poisoning of the reforming catalyst and the hollowing of the reforming unit upstream side due to the increase of the reforming catalyst packing density leads to reforming of the reforming unit upstream side. The reaction does not proceed and the endothermic amount on the upstream side of the reforming section decreases. As a result, the temperature rises, the reforming catalyst is sintered, the hydrocarbon-based raw material is thermally decomposed, and problems arise in operation controllability due to the change in the heat balance of the steam reformer. In order to restore this, the reforming catalyst is replaced. However, for the replacement, the reformer needs to be disassembled, which takes much time.

  Here, regarding the problem of operation controllability, in addition to the problem on the upstream side of the reforming unit, when there is a CO shift catalyst unit in the vicinity of the upstream side of the reforming unit, the temperature rises at the inlet, and further, This will affect the temperature balance of the entire instrument. In order to lower the increased temperature, it is necessary to take measures to increase the amount of water to be introduced (increase the S / C ratio). Thus, the increase in the temperature upstream of the reforming section (a) reduces the life of the entire reformer, (b) increases the time and effort for setting the operation sequence according to the change in the S / C ratio, and (c) It also causes a decrease in reformer efficiency due to an increase in the S / C ratio.

  Therefore, the present invention is based on the discovery of the above-mentioned problems in the reforming catalyst part of the conventional steam reformer and the elucidation of the cause thereof, to solve the problems and to provide a hydrocarbon-based raw material that can be stably operated over a long period of time. The object is to provide a steam reformer.

  In the present invention (1), a reforming catalyst portion is disposed in a gap between double cylinders constituted by an outer tube and an inner tube, and a mixed gas of hydrocarbon-based raw material and steam is introduced from the upstream of the reforming catalyst portion, and downstream Is a steam reformer from which hydrogen-rich reformed gas is discharged. A reforming guard catalyst portion filled with the reforming catalyst is arranged following the upstream end of the reforming catalyst portion, and the amount of the reforming catalyst filled in the reforming guard catalyst portion is determined by the reforming catalyst portion and the reforming guard. 7% or more of the total amount of the reforming catalyst in the catalyst section, and the mixed gas of hydrocarbon-based raw material and steam flows to the reforming guard catalyst section and the reforming catalyst section, and the hydrogen-rich reformed gas is discharged from the downstream. It is characterized by having a structure.

  In the present invention (2), the reforming catalyst part is arranged inside a single cylinder constituted by an outer pipe, and a mixed gas of hydrocarbon-based raw material and steam is introduced from the upstream of the reforming catalyst part, and the hydrogen-rich from the downstream. A steam reformer from which reformed gas is discharged. A reforming guard catalyst portion filled with the reforming catalyst is arranged following the upstream end of the reforming catalyst portion, and the amount of the reforming catalyst filled in the reforming guard catalyst portion is determined by the reforming catalyst portion and the reforming guard. 7% or more of the total amount of the reforming catalyst in the catalyst section, and the mixed gas of hydrocarbon-based raw material and steam flows to the reforming guard catalyst section and the reforming catalyst section, and the hydrogen-rich reformed gas is discharged from the downstream. It is characterized by having a structure.

  In the present invention (3), the reforming catalyst portion is disposed in the gap between the double cylinders constituted by the outer tube and the inner tube, and a mixed gas of hydrocarbon-based raw material and steam is introduced from the upstream of the reforming catalyst portion, and the downstream Is a steam reformer from which hydrogen-rich reformed gas is discharged. A reforming guard catalyst portion filled with the reforming catalyst is arranged following the upstream end of the reforming catalyst portion, and the amount of the reforming catalyst filled in the reforming guard catalyst portion is determined by the reforming catalyst portion and the reforming guard. 7% or more of the total amount of the reforming catalyst in the catalyst part, and a mixed gas of hydrocarbon raw material and steam is introduced from the boundary between the reforming guard catalyst part and the reforming catalyst part, The structure is characterized in that it does not flow but flows from the upstream side to the downstream side in the reforming catalyst part, and the hydrogen-rich reformed gas is discharged from the downstream side.

  In the present invention (4), the reforming catalyst portion is arranged inside a single cylinder constituted by an outer tube, and a mixed gas of hydrocarbon-based raw material and steam is introduced from the upstream of the reforming catalyst portion, and the hydrogen-rich from the downstream. A steam reformer from which reformed gas is discharged. A reforming guard catalyst portion filled with the reforming catalyst is arranged following the upstream end of the reforming catalyst portion, and the amount of the reforming catalyst filled in the reforming guard catalyst portion is determined by the reforming catalyst portion and the reforming guard. 7% or more of the total amount of the reforming catalyst in the catalyst part, and a mixed gas of hydrocarbon raw material and steam is introduced from the boundary between the reforming guard catalyst part and the reforming catalyst part, The structure is characterized in that it does not flow but flows from the upstream side to the downstream side in the reforming catalyst part, and the hydrogen-rich reformed gas is discharged from the downstream side.

  In the steam reformer of the present invention, the reforming guard catalyst part filled with the reforming catalyst is arranged upstream of the reforming catalyst part, so that methane, ethane, propane, butane, city gas, petroleum gas, or natural gas Production of hydrogen from gas and other hydrocarbon-based raw materials, and stable operation over a long period of time without the need to sinter the reforming catalyst, pyrolysis of hydrocarbon-based raw materials, and the heat balance of the steam reformer Can do. The steam reformer of the present invention is applied to supply hydrogen as a fuel for PEFC, for example.

  As the reforming catalyst, there are a metal catalyst and various other reforming catalysts, which are appropriately selected and used. Of these, a Ni or Ru metal catalyst is preferably used, and the metal catalyst is usually supported on a carrier such as alumina. The shape may be a monolith type in addition to a granular shape, a pellet shape, a tablet shape or the like (hereinafter referred to as “granular reforming catalyst” as appropriate). The monolithic reforming catalyst is a reforming catalyst in which a metal catalyst such as Ni or Ru is supported on the inner surface of a ceramic or metal carrier having a number of parallel through holes, that is, cells.

  The reforming guard catalyst part serves to guard the reforming catalyst of the reforming catalyst part from leaked sulfur. This is the first role of the reforming guard catalyst part, and is the same when a granular reforming catalyst is used as the reforming catalyst of the reforming catalyst part and when a monolithic reforming catalyst is used.

  When the present invention is not applied, poisoning from the reforming catalyst upstream of the reforming catalyst portion due to the leaked sulfur content reduces the catalytic activity. In the present invention, however, the reforming guard catalyst portion The reforming catalyst in the catalyst part can be protected from sulfur poisoning.

  Further, when the reforming catalyst of the reforming catalyst part is a granular reforming catalyst, the reforming guard catalyst part plays a role of supplementing the reforming catalyst of the reforming catalyst part in addition to the above role. This is the second role of the reforming guard catalyst part. Although the granular reforming catalyst may be crushed and pulverized although it is very little, the reforming guard catalyst part can compensate for it.

  In the case where the present invention is not applied, the granular reforming catalyst in the reforming catalyst portion has a higher packing density as the start-stop is repeated, and accordingly, a cavity is formed in the upper portion of the reforming catalyst portion. However, in the present invention, the reforming guard catalyst unit supplements the reforming catalyst and absorbs the steam reforming reaction at the inlet to the reforming catalyst unit. This prevents a decrease in the amount of heat and prevents a temperature rise at the reforming section inlet.

  In the steam reformer of the present invention, the amount of the reforming catalyst charged in the reforming guard catalyst portion is determined based on the role of the reforming guard catalyst portion, that is, the placement catalyst, It is 7% or more of the total amount of the reforming catalyst in the reforming guard catalyst part. The upper limit is not particularly limited, but is preferably 60%.

  Further, the reforming catalyst filled in the reforming catalyst layer and the reforming catalyst filled in the reforming guard catalyst part may be the same reforming catalyst or different reforming catalysts. Different reforming catalysts mean reforming catalysts with different supported metals, supports or particle sizes.

  Hereinafter, embodiments of the present invention will be sequentially described with reference to the drawings. In the following, the case of a granular reforming catalyst is described, but the same applies to the case of a monolith type reforming catalyst.

<Aspect 1 of the present invention>
According to the first aspect of the present invention, in the steam reformer for hydrocarbon-based raw materials, the outer tube that extends to the upstream end of the reforming catalyst section is extended in the circumferential direction, that is, the outer tube is connected to the central axis [one point in FIG. This is a mode in which a reforming guard catalyst part having a structure extending in a direction perpendicular to the chain line reference and having a height in the vertical direction is arranged following the upstream end of the reforming catalyst part.

  2 to 3 are diagrams for explaining the first aspect. 3A is an enlarged view of a portion including the reforming catalyst layer 16 and the reforming guard catalyst unit 51 in FIG. 2, and FIG. 3B is an enlarged view of the reforming guard catalyst unit 51. 2 to 3 are shown as longitudinal sectional views. This also applies to the following drawings. Moreover, in FIGS. 2 to 3, the same reference numerals as those in FIG. This also applies to the following drawings.

  The reforming catalyst layer 16 is configured by filling the reforming catalyst in an annular gap between the inner tube 1 and the outer tube 2. In the first aspect, the reforming guard catalyst unit 51 is provided following the upstream end of the reforming catalyst layer 16. The reforming guard catalyst unit 51 has a structure in which the upper part of the reforming catalyst layer 16 in the outer tube 2 extends (that is, expands) in a direction perpendicular to the central axis and has a height in the vertical direction. The space between the extended outer tube 2 and the inner tube 1 is filled with a reforming catalyst.

  More specifically, the reforming catalyst is filled in the “space formed in a substantially triangular cross section” formed by the partition wall 52, the partition wall 53, and the inner tube 1 to form the reforming guard catalyst unit 51. The “space formed in the shape of a substantially triangular section” includes a section-shaped space formed by the partition wall 52, the partition wall 53, and the dotted line R, and a rectangular section formed by the dotted line R, the dotted line S, and the inner tube 1. It is a space that is combined with the shape space, and is a space having a “height in the vertical direction” as indicated by “h” in FIG. Then, the reforming guard catalyst unit 51 is configured by filling the “space formed in a substantially triangular cross section” with the reforming catalyst.

During operation, the mixed gas of the hydrocarbon-based raw material and water vapor flows from the reforming guard catalyst unit 51 to the reforming catalyst unit, and then flows through the reforming guard catalyst unit 51 to the reforming catalyst layer 16.
In FIGS. 3A to 3B, dotted lines R and S are provided for convenience of description, and do not indicate partition walls. This also applies to dotted lines R and S in the following drawings.

  The reforming guard catalyst unit 51 serves to guard the reforming catalyst of the reforming catalyst layer 16 from leaked sulfur. Further, the reforming guard catalyst unit 51 serves to supplement the reforming catalyst of the reforming catalyst layer 16 when the reforming catalyst is a granular reforming catalyst. As long as these objects can be achieved, the angles of the partition wall 52 and the partition wall 53 with respect to the dotted line S and the lengths of the partition wall 52 and the partition wall 53 can be selected as appropriate. As an actual machine of the first aspect, among the total amount of the reforming catalyst filled in the reforming catalyst layer 16 and the reforming guard catalyst part 51, a reforming guard catalyst part 51 filled with 13% was produced.

  FIG. 3C is an enlarged view of a portion including the catalyst support 17 of the reforming catalyst layer 16. The reforming catalyst of the reforming catalyst layer 16 is supported by a support 17 such as a perforated plate or a mesh body fixedly disposed between the lower outer periphery of the inner tube 1 and the lower inner periphery of the outer tube 2. In this respect, the same applies to FIGS. 1, 4 to 9, and 12 to 13, and although not shown, the same applies to FIGS. 14 to 15.

<Aspect 2 of the present invention>
According to the second aspect of the present invention, in the steam reformer of a hydrocarbon-based raw material, the outer tube that extends to the upstream end of the reforming catalyst section extends in the circumferential direction and the axial direction, that is, the outer tube is centered on the central axis [FIG. ) Refer to middle one-dot chain line] This is a mode in which a reforming guard catalyst portion having a structure extending in a perpendicular direction and an axial direction and having a height in the vertical direction is arranged following the upstream end of the reforming catalyst portion. The aspect 1 differs from the aspect 1 in that the outer pipe that continues to the upstream end of the reforming catalyst portion is also extended in the axial direction.

  4-5 is a figure explaining the aspect 2 of this invention. FIG. 5A is an enlarged view of a portion including the reforming catalyst layer 16 and the reforming guard catalyst unit 61 in FIG. 4, and FIG. 5B is an enlarged view of the reforming guard catalyst unit 61.

  The reforming catalyst layer 16 is configured by filling a reforming catalyst into an annular gap between the inner tube 1 and the outer tube 2. And in aspect 2, the reforming guard catalyst part 61 is provided following the upstream end of the reforming catalyst layer 16. The reforming guard catalyst unit 61 extends (that is, expands) the upper portion of the reforming catalyst layer 16 in the outer tube 2 in the direction perpendicular to the central axis and in the axial direction, and has a height in the vertical direction. The structure is configured by filling the space between the extended outer tube 2 and the inner tube 1 with a reforming catalyst.

  More specifically, the space formed by the partition wall 62, the partition wall 63, the partition wall 64, and the inner pipe 1 is filled with the reforming catalyst to form the reforming guard catalyst unit 61. The space includes a trapezoidal space formed by the partition wall 62, the partition wall 63, the partition wall 63, and the dotted line R, and a rectangular cross-sectional space formed by the dotted line R, the dotted line S, and the inner tube 1. As shown in FIG. 5B as “h”, this is a “space having a height in the vertical direction”. And the reforming guard catalyst part 61 is comprised by filling the said space with the reforming catalyst.

  Here, the partition wall 63 has a shape in which the outer tube 2 extends in the axial direction in the same direction as the central axis (see the alternate long and short dash line in FIG. 5A). Since the space formed by 63, the partition wall 64, and the dotted line R is formed in a trapezoidal cross section, more reforming catalyst can be filled as compared with the substantially triangular space in the first aspect. As an actual machine of the present aspect 2, among the total amount of the reforming catalyst filled in the reforming catalyst layer 16 and the reforming guard catalyst unit 61, 46% of the reforming guard catalyst unit 61 was filled.

  The reforming guard catalyst unit 61 serves to guard the reforming catalyst of the reforming catalyst layer 16 from leaked sulfur. Further, the reforming guard catalyst unit 61 serves to compensate for the reforming catalyst of the reforming catalyst layer 16 when the reforming catalyst is a granular reforming catalyst. As long as these objects can be achieved, the angles of the partition wall 62 and the partition wall 64 with respect to the dotted line S or the partition wall 63 and the lengths of the partition wall 62, the partition wall 64, and the partition wall 63 can be selected as appropriate. During operation, the mixed gas of the hydrocarbon-based raw material and steam flows through the reforming guard catalyst unit 61 to the reforming catalyst layer 16.

<Aspect 3 of the present invention>
Aspect 3 of the present invention is a hydrocarbon raw material steam reformer in which the outer tube and the inner tube following the upstream end of the reforming catalyst section are contracted in the circumferential direction and the axial direction, that is, the outer tube and the inner tube are centered. A mode in which a reforming guard catalyst part having a structure which is contracted in a direction perpendicular to the axis (see the alternate long and short dash line in FIG. 5A) and in the axial direction and has a height in the vertical direction is arranged upstream of the reforming catalyst part. It is. 6-7 is a figure explaining the aspect 3 of this invention. FIG. 7A is an enlarged view of a portion including the reforming catalyst layer 16 and the reforming guard catalyst portion 71 in FIG. 6, and FIG. 7B is an enlarged view of the reforming guard catalyst portion 71.

  The reforming catalyst layer 16 is configured by filling a reforming catalyst into an annular gap between the inner tube 1 and the outer tube 2. In the third aspect, a reforming guard catalyst portion 71 is provided following the upstream end of the reforming catalyst layer 16. The reforming guard catalyst unit 71 is narrowed in the inner tube 1 and the outer tube 2 following the upstream end of the reforming catalyst unit, contracted in the circumferential direction and the axial direction (that is, contracted), and heightened in the vertical direction. It is constituted by filling the inclined space with a reforming catalyst.

  More specifically, the inclined space of the inclined portion 72 is connected to the upper end of the inner pipe 1 on the reforming catalyst layer 16 side as indicated by 1 ′ in FIG. 7B, and the inclined portion 73 is in FIG. 7B. As shown as 2 ', it is connected to the upper end side of the inner tube 2 on the reforming catalyst layer 16 side, formed between 1', the inclined portion 72, the dotted line S, 2 ', and the inclined portion 73, and 7 (b) is a space having a height in the vertical direction as indicated by “h”. The reforming guard catalyst unit 71 is configured by filling the “inclined space” with the reforming catalyst.

  Further, since the reforming catalyst layer 16 is connected to the wide portion of the reforming guard catalyst portion 71 having an inclination in the positional relationship with the reforming catalyst layer 16, the inner tube 1 that forms the reforming catalyst layer 16. The diameter of the outer tube 2 is increased accordingly. Regarding the “inclined space” filled with the reforming catalyst, from the preheating layer 14 side, the inner tube 1 and the outer tube 2 forming the preheating layer 14 are arranged in the circumferential direction (that is, in a direction perpendicular to the central axis). In addition, it can be described as a structure that extends downward (i.e., expands) and has a height in the vertical direction.

  The reforming guard catalyst unit 71 serves to guard the reforming catalyst of the reforming catalyst layer 16 from leaked sulfur. Further, the reforming guard catalyst portion 71 serves to compensate for the reforming catalyst of the reforming catalyst layer 16 when it is a granular reforming catalyst. To the extent that these objectives can be achieved, the degree of inclination of the inclined part 72 of the inner pipe 1, the degree of inclination of the inclined part 73 of the outer pipe 2, the width between the inclined part 72 and the inclined part 73, and modification The vertical height of the guard catalyst unit 71 can be selected as appropriate. Thereby, it becomes a structure which can be filled with more reforming catalysts.

<Aspect 4 of the present invention>
According to Aspect 4 of the present invention, in the steam reformer for hydrocarbon-based raw material, a reforming guard catalyst part having a structure in which the inner pipe of the reforming catalyst part is shrunk in the circumferential direction is arranged following the upstream end of the reforming catalyst part. This is the embodiment. FIG. 8 is a diagram for explaining the fourth aspect. FIG. 8B is an enlarged view showing a portion including the guard catalyst portion 81 in FIG.

  The reforming catalyst unit 16 is configured by filling a reforming catalyst into an annular gap between the inner tube 1 and the outer tube 2. And in aspect 4, the reforming guard catalyst part 81 is provided following the upstream end of the reforming catalyst layer 16. The reforming guard catalyst unit 81 has a structure in which the inner pipe 1 continuing from the preheating layer 14 is contracted in the circumferential direction.

  A reforming guard catalyst portion 81 is provided following the upstream end of the reforming catalyst layer 16. The reforming guard catalyst unit 81 has a structure in which an upper portion of the inner tube 1 is contracted (that is, contracted) in a direction perpendicular to the central axis and has a height in the vertical direction. The space between the contracted inner tube 1 and the outer tube 2 is filled with a reforming catalyst.

  A reforming catalyst is filled in a “space formed in a substantially triangular cross section” formed by the partition wall 82, the partition wall 83, and the outer tube 2, thereby forming a reforming guard catalyst portion 81. More specifically, the “space formed in a substantially triangular cross section” is a space formed by the partition wall 82, the partition wall 83, and the dotted line R, and a rectangular cross section formed by the dotted line R, the dotted line S, and the outer tube 2. The space is a space having a height in the vertical direction as indicated by “h” in FIG. 8B. The reforming guard catalyst unit 81 is configured by filling the “space formed in a substantially triangular cross section” with the reforming catalyst.

  The reforming guard catalyst unit 81 serves to guard the reforming catalyst of the reforming catalyst layer 16 from leaked sulfur. Further, the reforming guard catalyst portion 81 serves to supplement the reforming catalyst of the reforming catalyst layer 16 when the reforming catalyst is a granular reforming catalyst. As long as these objects can be achieved, the angles of the partition wall 82 and the partition wall 83 with respect to the dotted line R, and the lengths of the partition wall 82 and the partition wall 83 can be selected as appropriate.

<Aspect 5 of the present invention>
In the fifth aspect of the present invention, as in the fourth aspect, in the steam reformer of the hydrocarbon-based raw material, the reforming guard catalyst portion having a structure in which the inner pipe of the reforming catalyst portion is contracted in the circumferential direction is replaced with the reforming catalyst portion. It is the aspect arrange | positioned following an upstream end. FIG. 9 is a diagram for explaining the fifth aspect, and FIG. 9B is an enlarged view of a portion including the guard catalyst portion 91 in FIG. 9A.

  The reforming catalyst unit 16 is configured by filling a reforming catalyst into an annular gap between the inner tube 1 and the outer tube 2. And in aspect 5, the reforming guard catalyst part 91 is provided following the upstream end of the reforming catalyst layer 16. The reforming guard catalyst unit 91 has a structure in which an upper portion of the inner pipe 1 is contracted (that is, contracted) in the circumferential direction, that is, in a direction perpendicular to the central axis, and has a height in the vertical direction. The space between the contracted inner tube 1 and the outer tube 2 is filled with a reforming catalyst.

  The “space” formed by the partition wall 92, the partition wall 93, and the outer tube 2 is filled with the reforming catalyst to form the reforming guard catalyst unit 91. More specifically, the “space” is a space obtained by combining a space formed by the partition wall 92, the partition wall 93 and the dotted line R, and a space having a rectangular cross section formed by the dotted line R, the dotted line S and the outer tube 2. This space is a space “having a height in the vertical direction” as indicated by “h” in FIG. 9B. Then, the reforming guard catalyst unit 91 is configured by filling the “space” with the reforming catalyst.

  The reforming guard catalyst unit 91 serves to guard the reforming catalyst of the reforming catalyst layer 16 from leaked sulfur. Further, the reforming guard catalyst unit 91 serves to supplement the reforming catalyst of the reforming catalyst layer 16 when the reforming catalyst is a granular reforming catalyst. As long as these objects can be achieved, the angles of the partition wall 92 and the partition wall 93 with respect to the dotted line R, and the lengths of the partition wall 92, the partition wall 93, and the partition wall 94 can be selected as appropriate.

  The aspect described above is an aspect in which the steam reformer is installed with the upstream side of the reforming catalyst layer 16 or the reforming unit on the upper side and the downstream side thereof with the lower side, but the present invention is installed upside down, It is also applied to steam reformers such as oblique installation and horizontal installation. For example, in the case of a steam reformer installed upside down, the reforming guard catalyst unit is arranged below the reforming catalyst unit following the upstream end of the reforming catalyst unit.

<Aspect 6 of the present invention>
This aspect 6 is an aspect which applied the steam reformer of the said aspect 1 to the steam reformer installed upside down. 10 to 11 are diagrams for explaining the sixth aspect. 11A is an enlarged view of a portion including the reforming catalyst layer 16 and the reforming guard catalyst unit 101 in FIG. 10, and FIG. 11B is an enlarged view of the reforming guard catalyst unit 101. is there. In FIG. 11, a member denoted by reference numeral 100 is a catalyst support composed of a perforated plate, a mesh body, and the like, and is fixedly disposed between the lower outer periphery of the inner tube 1 and the lower inner periphery of the outer tube 2.

  The reforming catalyst layer 16 is configured by filling a reforming catalyst into an annular gap between the inner tube 1 and the outer tube 2. To this end, in the aspect 6, the reforming guard catalyst unit 101 is provided following the upstream end of the reforming catalyst layer 16. The reforming guard catalyst unit 101 extends (i.e., expands) the lower portion of the outer tube 2 in a direction perpendicular to the axial direction (see the alternate long and short dash line in FIG. 11A) and has a height in the vertical direction. The structure is configured by filling the space between the extended outer tube 2 and the inner tube 1 with a reforming catalyst.

  More specifically, the reforming catalyst is filled in the “space formed in a substantially triangular cross section” formed by the partition wall 102, the partition wall 103, and the inner tube 1 to form the reforming guard catalyst unit 101. The “space formed in a substantially triangular cross-section” is a space having a triangular cross-section formed by the partition wall 102, the partition wall 103 and the dotted line R, the dotted line R, the catalyst support 100, the inner tube 1, and the dotted line S. The space is formed by combining the formed space having a rectangular cross section, and this space is a “having a height in the vertical direction” as indicated by “h” in FIG. The reforming guard catalyst unit 101 is configured by filling the “space formed in a substantially triangular cross section” with the reforming catalyst.

  The reforming guard catalyst unit 101 serves to guard the reforming catalyst of the reforming catalyst layer 16 from leaked sulfur. As long as this object can be achieved, the angles of the partition wall 102 and the partition wall 103 with respect to the dotted line R, and the lengths of the partition wall 102 and the partition wall 103 can be selected as appropriate.

<Aspect 7 of the present invention>
In this aspect 7, the reforming catalyst part is disposed in the gap between the double cylindrical containers constituted by the outer pipe and the inner pipe, and a mixed gas of hydrocarbon-based raw material and steam is introduced from the upstream of the reforming catalyst part, and the downstream This is a mode in which the reforming guard catalyst part is applied to the steam reformer from which hydrogen-rich reformed gas is discharged. A reforming guard catalyst part is arranged following the upstream end of the reforming catalyst part. Then, a mixed gas of hydrocarbon-based raw material and steam is introduced from the boundary between the reforming guard catalyst part and the reforming catalyst part, and flows from the upstream side to the downstream side of the reforming catalyst part. It is a structure where gas is discharged.

  12 to 13 are diagrams for explaining the seventh aspect. FIG. 13A is an enlarged view of the portion including the reforming catalyst portion in FIG. 12, and FIGS. 13B to 13C show the reforming guard catalyst portion in FIG. It is the figure which took out and expanded and showed the part containing.

  The reforming catalyst layer 16 is configured by filling a reforming catalyst in an annular gap between the inner tube 1 and the outer tube 2. In the aspect 7, for example, the inner tube 1 and the outer tube 2 are extended upward in the axial direction (see the one-dot chain line in FIG. 13A), and the annular gap between the extended inner tube 1 and the outer tube 2 is modified. The reforming guard catalyst unit 111 is provided by filling the quality catalyst. An upper lid 112 corresponding to the annular gap is provided between the upper end side of the outer tube 2 and the outer periphery of the inner tube 1. The upper lid 112 is a donut-shaped upper lid because a portion corresponding to the diameter of the inner tube 1 is occupied by the inner tube 1.

  In the outer pipe 2, a plurality of pores 113 for introducing a mixed gas of hydrocarbon-based raw material and water vapor are provided at the position of the boundary portion between the reforming catalyst layer 16 and the reforming guard catalyst portion 111. Since the boundary portion is annular, the plurality of pores 113 are preferably provided at equal intervals in the annular boundary portion.

  As described above, the reforming guard catalyst unit 111 is configured by filling the annular gap between the inner tube 1 and the outer tube 2 and the upper lid 112 extending upward in the axial direction with the reforming catalyst. As an actual machine of the seventh aspect, among the total amount of the reforming catalyst filled in the reforming catalyst layer 16 and the reforming guard catalyst part 111, a reforming guard catalyst part 111 filled with 13% was produced. During operation, the mixed gas of the hydrocarbon-based raw material and water vapor flows as shown by arrows in FIGS. 13A and 13C and is introduced into the reforming catalyst unit 16 through the plurality of pores 113 to be reformed. From the upstream side to the downstream side of the catalyst unit 16, the reformed gas rich in hydrogen is discharged from the downstream side. In the present embodiment 7, the reformed guard catalyst unit 111 does not flow a mixed gas of hydrocarbon-based raw material and water vapor.

  The reforming guard catalyst unit 111 serves to supplement the reforming catalyst of the reforming catalyst layer 16. The length of the reforming guard catalyst unit 111 can be selected as appropriate as long as this purpose can be achieved.

<The factor of the temperature rise inhibitory effect in aspects 1-7 of this invention>
According to the present invention, a temperature increase upstream of the reforming unit is suppressed by the reforming guard catalyst unit. The reason is understood to be due to the following factors and effects (a) to (c).
(A) The reforming guard catalyst portion is filled with the reforming catalyst following the upstream end of the reforming catalyst portion of the mixed gas of hydrocarbon-based raw material and steam, and the amount of the reforming catalyst is increased, whereby the reforming catalyst by sulfur Can alleviate poisoning.
(B) The reforming catalyst filled in the reforming guard catalyst section allows the reforming catalyst in the reforming section to settle and be replenished even when the reforming catalyst becomes insufficient. Can be prevented.
(C) Compared with the conventional one (for example, the one shown in FIG. 1), by increasing the diameter that follows the upstream end of the reforming catalyst unit, the flow rate of the mixed gas of hydrocarbon-based raw material and steam is reduced, Movement can be reduced. Accordingly, even if the reforming catalyst on the upstream side of the reforming catalyst portion deteriorates due to sulfur poisoning and the endotherm is reduced, it is difficult for heat to be transmitted, so that the temperature rise can be suppressed.

  Table 1 considers the degree of involvement of these factors (a) to (c) for each of the aspects 1 to 6. In Table 1, ◎ means very effective, ○ means effective, Δ means less effective than ○,-means no effect as in the conventional case.

<Aspects 8 to 9 of the present invention>
In the above aspect, the reforming catalyst portion is disposed in the gap between the double cylindrical containers constituted by the outer tube and the inner tube, the mixed gas of hydrocarbon-based raw material and steam is introduced from the upstream of the reforming catalyst portion, and the downstream This is an embodiment applied to a steam reformer that discharges hydrogen-rich reformed gas from the steam generator. In the present invention, a reforming catalyst unit is disposed in a single cylindrical vessel, a mixed gas of a hydrocarbon-based material and steam is introduced from the upstream of the reforming catalyst unit, and a steam reformer that discharges a hydrogen-rich reformed gas from the downstream. It is also applied to the quality device.

<Aspect 8>
FIG. 14 is a diagram for explaining this aspect 8. FIG. 14B is an enlarged view showing a portion including the reforming guard catalyst portion in FIG. 14A. As shown in FIG. 14, a reforming guard catalyst 121 is provided following the upstream end of the reforming catalyst having a structure in which a single cylindrical container constituted by a cylindrical tube (outer tube) 122 is filled with a reforming catalyst. That is, the diameter of the cylindrical tube that follows the upstream end of the columnar reforming catalyst portion is increased and the reforming catalyst is filled therein to provide the reforming guard catalyst portion 121.

  More specifically, the diameter is made larger than the diameter of the cylindrical tube 122 as indicated by reference numeral 124 in FIG. A portion denoted by reference numeral 123 is an inclined portion between the tubular tube 122 and the tubular tube 124. The space is formed by a cylindrical tube 124, an inclined cylindrical tube 123, and a dotted line S, and this space is a “longitudinal height” space as indicated by “h” in FIG. It is. And the reforming guard catalyst part 121 is comprised by filling the said space with the reforming catalyst.

  The mixed gas of the hydrocarbon-based raw material and steam flows through the reforming guard catalyst unit 121 to the reforming catalyst unit. In addition, the said pipe | tube in aspect 8 is equivalent to the outer pipe | tube in the relationship with the steam reformer of the type which has arrange | positioned the reforming catalyst part in the clearance gap between the double cylindrical containers comprised with the above-mentioned outer pipe | tube and an inner pipe | tube. Therefore, the term “outer tube” is used as appropriate in the present specification and claims.

  Also in this aspect, the reforming guard catalyst part serves to guard the reforming catalyst of the reforming catalyst part from leaked sulfur. This is an important role of the reforming guard catalyst part. Further, when the reforming catalyst of the reforming catalyst layer is a granular reforming catalyst, the reforming guard catalyst portion plays a role of supplementing the reforming catalyst of the reforming catalyst portion in addition to the above role. Although the granular reforming catalyst may be crushed and pulverized although it is very little, the reforming guard catalyst part can compensate for it.

<Aspect 9>
FIG. 15 is a diagram for explaining the aspect 9. As shown in FIG. 15, a reforming guard catalyst 131 is provided following the upstream end of the reforming catalyst having a structure in which a single cylindrical container constituted by a cylindrical tube (outer tube) 132 is filled with a reforming catalyst. That is, the single cylindrical container is extended upward from the upstream end portion of the columnar reforming catalyst portion, and the reforming catalyst is filled in the extended space to form the reforming guard catalyst portion 131. Then, a mixed gas of the hydrocarbon-based raw material and water vapor is introduced from the boundary between the reforming guard catalyst part 131 and the reforming catalyst part (part indicated by S) and flows from the upstream side to the downstream side of the reforming catalyst part. The hydrogen-rich reformed gas is discharged from the downstream.

  The mixed gas of hydrocarbon-based raw material and water vapor does not flow through the reforming guard catalyst portion 131 of the present embodiment 9. Note that the pipe 132 in the aspect 9 corresponds to the outer pipe in the relationship with the steam reformer of the type in which the reforming catalyst portion is disposed in the gap between the double cylindrical containers constituted by the outer pipe and the inner pipe. Therefore, the term “outer tube” is used as appropriate in the present specification and claims.

  In the present aspect 9, the reforming guard catalyst part serves to supplement the reforming catalyst of the reforming catalyst layer. The length of the reforming guard catalyst portion can be selected as appropriate as long as this object can be achieved.

<Aspect example of steam reformer of hydrocarbon raw material targeted in the present invention>
The hydrocarbon-based raw material steam reformer of the present invention is a hydrocarbon-based raw material of a type in which a reforming catalyst portion, a CO shift catalyst portion, and a CO removal catalyst portion are divided into separate layers in a cylindrical vessel. It can also be applied to other steam reformers. As an example, a steam reformer including the following configurations (1) to (5) can be provided.
(1) Concentrically spaced apart inner pipes (= first cylinder), outer pipe (= second cylinder), third cylinder, and third cylinders, which are successively larger in diameter. A fourth cylinder having a diameter larger than that of the three cylinders is provided.
(2) A radiation cylinder is provided in the inner tube with the central axis coaxial.
(3) A reforming catalyst layer provided with a burner in the axial direction in the radiation tube and filled with the reforming catalyst in a gap defined by the inner tube and the outer tube is disposed.
(4) A CO conversion catalyst layer and a CO removal catalyst layer are sequentially arranged between the outer tube and the fourth cylindrical body with an interval in the axial direction through a partition wall.
(5) The flow of the reformed gas in the CO removal catalyst layer is configured to flow radially from the axial direction or from the central axis side to the outer periphery.

As the CO conversion catalyst of the CO conversion catalyst layer, a Cu / Zn-based catalyst, an Fe / Cr-based catalyst, a white metal catalyst, a catalyst containing platinum as a main component and a metal oxide such as CeO ₂ as an auxiliary component, Al, Cu, It is appropriately selected from base metal catalysts such as Fe, Cr and Mo, and other CO shift catalysts. Platinum-based catalysts are resistant to deterioration due to oxidation, etc., and can be used continuously even in a high temperature range of 350 ° C or higher, particularly in a high temperature range of 400 ° C or higher, and the reaction proceeds at a faster rate. Can be made. As the CO conversion catalyst, a single CO conversion catalyst may be used, or a high temperature CO conversion catalyst and a low temperature CO conversion catalyst may be used in combination. As the CO conversion catalyst, in addition to the granular CO conversion catalyst, a monolith type CO conversion catalyst is used.

  The CO removal catalyst is not particularly limited as long as it can selectively oxidize CO in the reformed gas. For example, a Ru-based metal-supported catalyst is used. The metal-supported catalyst is configured, for example, by supporting a metal such as Ru on a support such as alumina.

  In the steam reformer targeted by the present invention, a heat-resistant alloy, preferably stainless steel, is used as a constituent member excluding the catalyst.

  As the heat insulating material 23, a material having good workability such as ceramic fiber is preferably used. As the heat insulating material 40, for example, a heat insulating material having a high heat insulating effect such as microtherm, calcium silicate, or alumina fiber is used.

  As the hydrocarbon-based material, methane, ethane, propane, butane, other hydrocarbons, city gas, petroleum gas, natural gas, and other mixed gas containing two or more kinds of hydrocarbons are used.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, of course, this invention is not limited to these Examples.

<Comparative example 1>
A sulfur poisoning test was conducted using the steam reformer shown in FIG. The present inventors have repeatedly started and stopped the actual steam reformer for a long period of time, and observed whether or not further improvements have been made, but this sulfur poisoning test was conducted as part of that. is there. The steam reformer is an apparatus capable of producing 1 Nm ³ of hydrogen per hour with the whole reformer (including the heat insulating material) having a height of 60 cm and a diameter of 20 cm. Each catalyst was filled in each of the reforming catalyst portion, the CO shift catalyst layer 21 and the CO removal catalyst layer 54. The height of the reforming catalyst part is 100 mm.

  As the reforming catalyst, a Ru-based catalyst (a catalyst having Ru supported on alumina, granular, average particle diameter (diameter) ≈3 mm) was used. As the CO conversion catalyst, a Cu / Zn-based catalyst [a catalyst obtained by extrusion molding with Cu and Zn supported on alumina, cylindrical shape, 3 mm (diameter) × 3 mm (length)] was used. As the CO removal catalyst, a Ru / platinum-based catalyst (a catalyst in which Ru is supported on granular alumina, granular, average particle diameter (diameter) ≈3 mm) was used.

City gas (13A) was used as a hydrocarbon-based raw material without desulfurization. City gas contains a sulfur compound of about several volppm as an odorant. Source gas was supplied at a flow rate of 4.1 NL / min, and water (pure water) was supplied at a flow rate of 10.0 g / min. The steam ratio (S / C ratio) = 2.5. In addition, CO removal air was supplied at a flow rate of 1.5 NL / min. City gas was used as fuel for the burner. In FIG. 1, temperature sensors were set at the reforming inlet and the reforming outlet as indicated by T ₁ and T ₂ .

  FIG. 16 shows the temperature changes at the reforming inlet and the reforming outlet as the measured operation time elapses. As shown in FIG. 16, the reformer inlet is poisoned by sulfur, and the temperature rises rapidly.

<Comparative example 2>
The temperature of the reforming inlet and the reforming outlet accompanying the start-stop is the same as in Comparative Example 1, except that city gas (13A) is used after desulfurization as the hydrocarbon-based raw material and the start-stop is repeated. Changes were measured. City gas contains a sulfur compound of about several volppm as an odorant, but desulfurized city gas is desulfurized by passing it through a high-performance desulfurization agent in which silver is supported on Y-type zeolite, and several volppb Desulfurized to the level.

  The results are shown in FIGS. First, as shown in FIG. 17, as the start-stop is repeated (with increasing and decreasing temperature), the reforming unit inlet is gradually poisoned by a slight sulfur content leaked from the desulfurizer, and the temperature gradually increases. Yes. Further, as shown in FIG. 18, the reforming catalyst continues to settle gradually up to about 650 times of temperature rise and fall, reaches a settling length of 7 mm (ratio 7%) at 720 times, and continues to settle further, although slightly after that. .

<Example>
The reforming inlet part and the reforming outlet accompanying the start-stop are the same as in the comparative example 2, except that the steam reformer shown in FIGS. 4 to 5 is used and the start-stop (with increasing temperature) is repeated. The temperature change of the part was measured. The steam reformer of FIG. 1 except that the reforming guard catalyst portion 61 is filled with 46% of the total reforming catalyst amount charged in the reforming catalyst layer 16 and the reforming guard catalyst portion 61. It is the same as the vessel. 4 to 5, temperature sensors were set at the reforming inlet and the reforming outlet as indicated by T ₁ and T ₂ .

  FIG. 19 shows the result. As shown in FIG. 19, slight sulfur leaked from the desulfurizer should have reached the reforming section, but the poisoning of sulfur is mitigated by the guard catalyst filled with a sufficient amount of reforming catalyst, There is almost no increase in temperature. In addition, the guard catalyst suppressed the settling of the reformed catalyst particles, and no settling was observed even when the number of start / stop operations was 1000 times. Thus, according to the present invention, in addition to the guard effect against sulfur, the effect of preventing sedimentation is achieved.

Diagram showing an example of an integrated steam reformer (prior art) The figure explaining the aspect 1 of this invention The figure explaining the aspect 1 of this invention The figure explaining aspect 2 of this invention The figure explaining aspect 2 of this invention The figure explaining aspect 3 of this invention The figure explaining aspect 3 of this invention The figure explaining aspect 4 of this invention The figure explaining aspect 5 of the present invention The figure explaining aspect 6 of this invention The figure explaining aspect 6 of this invention The figure explaining aspect 7 of this invention The figure explaining aspect 7 of this invention The figure explaining aspect 8 of this invention The figure explaining aspect 9 of this invention The figure which shows the result of the comparative example 1 The figure which shows the result of the comparative example 2 The figure which shows the result of the comparative example 2 The figure which shows the result of the Example of this invention

Explanation of symbols

1 1st cylinder (inner tube)
2 Second cylinder (outer tube)
DESCRIPTION OF SYMBOLS 3 3rd cylinder 4th 4th cylinder 5 radiation cylinder 6 burner 7 top cover and burner mounting base 8 bottom plate 9 flue gas exhaust passage 10 partition 16 reforming catalyst layer 17 reforming catalyst support body 36 of reforming catalyst layer 16 CO removal catalyst layer 51, 61, 71, 81, 91, 101, 111 121 131 Reforming guard catalyst part 52 to 53, 62 to 64, 72 to 73, 82 to 83, 92 to 94, 102 to 103 Partition wall h Vertical height R, S Dotted lines for convenience of explanation T ₁ , T ₂ Temperature sensor

Claims (16)

A reforming catalyst part is arranged in the gap between the double cylinders constituted by the outer pipe and the inner pipe, and a mixed gas of desulfurized hydrocarbon-based raw material and steam is introduced from the upstream of the reforming catalyst part, and the hydrogen-rich gas is introduced from the downstream. In the steam reformer from which the reformed gas is discharged , the reforming catalyst is charged after the upstream end of the reforming catalyst unit to protect the reforming catalyst in the reforming catalyst unit from sulfur poisoning due to leaked sulfur . The reforming guard catalyst portion is arranged, and the amount of the reforming catalyst filled in the reforming guard catalyst portion is 7% or more of the total amount of the reforming catalyst in the reforming catalyst portion and the reforming guard catalyst portion. Steam reforming of hydrocarbon feedstock, characterized in that a mixed gas of hydrogen feedstock and steam flows to the reforming guard catalyst section and reforming catalyst section, and hydrogen-rich reformed gas is discharged from downstream vessel. A reforming catalyst part is arranged inside a single cylinder constituted by an outer pipe, a mixed gas of desulfurized hydrocarbon-based raw material and steam is introduced from the upstream of the reforming catalyst part, and a hydrogen-rich reformed gas is introduced from the downstream. In the discharged steam reformer, a reforming guard catalyst filled with a reforming catalyst that serves to protect the reforming catalyst of the reforming catalyst portion from sulfur poisoning due to leaked sulfur components following the upstream end of the reforming catalyst portion The amount of the reforming catalyst filled in the reforming guard catalyst portion is 7% or more of the total amount of the reforming catalyst in the reforming catalyst portion and the reforming guard catalyst portion. A hydrocarbon-based raw material steam reformer characterized in that a mixed gas of steam flows into the reforming guard catalyst section and the reforming catalyst section, and a hydrogen-rich reformed gas is discharged from the downstream. A reforming catalyst part is arranged in the gap between the double cylinders constituted by the outer pipe and the inner pipe, and a mixed gas of desulfurized hydrocarbon-based raw material and steam is introduced from the upstream of the reforming catalyst part, and the hydrogen-rich gas is introduced from the downstream. In the steam reformer from which the reformed gas is discharged , the reforming catalyst is charged after the upstream end of the reforming catalyst unit to protect the reforming catalyst in the reforming catalyst unit from sulfur poisoning due to leaked sulfur . The reforming guard catalyst portion is arranged, and the amount of the reforming catalyst filled in the reforming guard catalyst portion is 7% or more of the total amount of the reforming catalyst in the reforming catalyst portion and the reforming guard catalyst portion. A mixed gas of hydrogen-based raw material and water vapor is introduced from the boundary between the reforming guard catalyst part and the reforming catalyst part, does not flow to the reforming guard catalyst part, and flows from the upstream side to the downstream side to the reforming catalyst part, Charcoal characterized in that hydrogen-rich reformed gas is discharged from downstream Steam reformer hydrogen based material. A reforming catalyst part is arranged inside a single cylinder constituted by an outer pipe, a mixed gas of desulfurized hydrocarbon-based raw material and steam is introduced from the upstream of the reforming catalyst part, and a hydrogen-rich reformed gas is introduced from the downstream. In the discharged steam reformer, a reforming guard catalyst filled with a reforming catalyst that serves to protect the reforming catalyst of the reforming catalyst portion from sulfur poisoning due to leaked sulfur components following the upstream end of the reforming catalyst portion The amount of the reforming catalyst filled in the reforming guard catalyst portion is 7% or more of the total amount of the reforming catalyst in the reforming catalyst portion and the reforming guard catalyst portion. A mixed gas of water vapor is introduced from the boundary between the reforming guard catalyst part and the reforming catalyst part, does not flow to the reforming guard catalyst part, flows to the reforming catalyst part from the upstream side to the downstream side, and is rich in hydrogen from the downstream side. Hydrocarbon system characterized in that it has a structure that discharges reformed gas Steam reformer of the fee. The steam reformer of the hydrocarbon-based raw material according to any one of claims 1 to 4, wherein the reforming catalyst unit is reformed from sulfur poisoning due to leaked sulfur, which is arranged subsequent to the upstream end of the reforming catalyst unit. A steam reformer for a hydrocarbon-based raw material, characterized in that a reforming guard catalyst portion filled with a reforming catalyst that serves to protect the catalyst has a structure in which an outer tube extends in the circumferential direction. The steam reformer of the hydrocarbon-based raw material according to any one of claims 1 to 4, wherein the reforming catalyst unit is reformed from sulfur poisoning due to leaked sulfur, which is arranged subsequent to the upstream end of the reforming catalyst unit. A steam reformer for a hydrocarbon-based raw material, characterized in that a reforming guard catalyst portion filled with a reforming catalyst that serves to protect the catalyst has a structure in which an outer tube extends in a circumferential direction and an axial direction. The steam reformer for hydrocarbon raw material according to claim 1 or 3, wherein the reforming catalyst in the reforming catalyst part is protected from sulfur poisoning due to leaked sulfur, which is arranged subsequent to the upstream end of the reforming catalyst part. A hydrocarbon-based raw material steam reformer characterized in that a reforming guard catalyst portion filled with a reforming catalyst that has a structure is formed by shrinking an outer tube and an inner tube in a circumferential direction and an axial direction. The steam reformer for hydrocarbon raw material according to claim 1 or 3, wherein the reforming catalyst in the reforming catalyst part is protected from sulfur poisoning due to leaked sulfur, which is arranged subsequent to the upstream end of the reforming catalyst part. A hydrocarbon-based raw material steam reformer characterized in that the reforming guard catalyst portion filled with the reforming catalyst for reducing the inner pipe is contracted in the circumferential direction.   9. The hydrocarbon-based raw material steam reformer according to claim 1, wherein the reforming catalyst part and the reforming guard catalyst part are filled with the same catalyst. Steam reformer.   9. The hydrocarbon-based raw material steam reformer according to claim 1, wherein the reforming catalyst section and the reforming guard catalyst section are filled with different catalysts. Reformer.   11. The hydrocarbon-based raw material steam reformer according to claim 9 or 10, wherein the reforming guard catalyst portion is filled with a Ni-based reforming catalyst.   The steam reformer for hydrocarbon-based raw materials according to any one of claims 1 to 11, wherein the amount of the reforming catalyst charged in the reforming guard catalyst part is the reforming of the reforming catalyst part and the reforming guard catalyst part. A steam reformer for a hydrocarbon-based raw material, characterized in that it is 60% or less of the total amount of the catalyst.   The steam reformer for a hydrocarbon-based raw material according to any one of claims 1 to 11, wherein an upstream side of the reforming guard catalyst unit disposed upstream of the reforming catalyst unit is an upper end, and the reforming guard catalyst unit A steam reformer for a hydrocarbon-based material, having a structure in which a mixed gas of a hydrocarbon-based material and steam is introduced from the upper end.   13. The hydrocarbon-based raw material steam reformer according to claim 1, wherein the reforming guard catalyst portion disposed upstream of the reforming catalyst portion has a lower end as a lower end, A hydrocarbon-based raw material steam reformer characterized in that a mixed gas of a hydrocarbon-based raw material and steam is introduced from the lower end of the guard catalyst section.   The hydrocarbon-based raw material steam reformer according to any one of claims 1 to 14 is a hydrocarbon-based raw material steam reformer for supplying hydrogen to a polymer electrolyte fuel cell. Steam reformer for hydrogen-based raw materials. The steam reformer for a hydrocarbon-based raw material according to any one of claims 1 to 14, wherein the reforming catalyst part, the CO shift catalyst part, and the CO removal catalyst part are arranged in separate layers in a container. A hydrocarbon raw material steam reformer characterized by being a hydrocarbon raw material steam reformer integrated.

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