JP3015662B2 - Reformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a reformer, and more particularly to a catalyst holder for the reformer.

[0002]

2. Description of the Related Art A fuel cell uses a hydrogen-rich gas and oxygen in the air to generate electric power. The hydrogen-rich gas is used in a reforming apparatus to reform a raw material gas such as natural gas or methanol by steam. Generated by FIG.
1 shows a schematic cross-sectional view of a main part of a conventional reformer. As shown in the figure, the reforming apparatus has a partitioning cylinder 10
1 and an inner cylinder 102 and an outer cylinder 1 concentrically arranged inside and outside thereof.
03, the lower end of the inner cylinder 102 and the outer cylinder 103
Is connected to a space 104 formed by the inner cylinder 102 and the partition cylinder 101 and a space 105 formed by the outer cylinder 103 and the partition cylinder 101. Further, an opening at the upper end of the inner cylinder 102 is closed by a combustion chamber top plate 106. The outer cylinder 103 and the partition cylinder 101 extend above the upper end of the inner cylinder 102, and the upper ends of the outer cylinder 103 and the partition cylinder 101 are closed by a reformer top plate 107. Space 1 formed by partition cylinder 101 and inner cylinder 102
In 04, a catalyst layer 108 is provided. The upper surface of the catalyst layer 108 is provided below the top plate 106, and a catalyst stopper 10 for holding the catalyst is provided at the lower end of the catalyst layer.
9 is provided from the lower end of the partition cylinder 101 to the inner cylinder 102. A donut-shaped catalyst holding plate 110 is provided on the catalyst layer 108.

[0003]

However, the conventional reforming apparatus has the following problems. The catalyst filled in the reformer may be subjected to vibrations during transportation, etc.
02 and the partitioning cylinder 101 repeat expansion and contraction, the catalyst moves, the catalyst becomes more densely packed, the particles of the catalyst collide with each other, or the wall surface of the member in contact with the catalyst rubs. Powder. In this way, the upper surface 108a of the catalyst layer 108 falls downward due to the increase in the packing density of the catalyst or the powdering due to the vibration or heat cycle.

At this time, the catalyst holding plate 110 on the catalyst layer 108 is donut-shaped and thick, and is in contact with the wall surfaces of the partitioning cylinder 101 and the inner cylinder 102, so that the contact portion is large and the space 104 Easy to get caught inside. Therefore, as the upper surface 108a of the catalyst layer 108 is lowered, it cannot move downward in the space 104, and a gap S is generated between the pressing plate 110 and the upper surface 108a of the catalyst layer 108 as shown in FIG. When the reformer is tilted in a state where the gap S is formed between the catalyst holding plate 110 and the upper surface 108a of the catalyst layer 108, the upper surface 108 of the catalyst layer 108
As shown in FIG.

[0005] For example, when a fuel gas composed of water vapor and a raw material gas is supplied from above the catalyst in a state where the upper surface of the catalyst layer 108 is inclined as described above, a portion having a lower upper end and a portion having a higher upper end are separated. In comparison, due to the pressure loss of the supplied fuel gas, the fuel gas easily flows into the lower end side, more fuel gas flows in, the endothermic reaction is biased, and the temperature distribution in the catalyst layer is increased. Is uneven.

Further, as shown in FIG. 6, even at the catalyst portions at points A and B located at the same height h, the upper surface 108a
Are different from each other, the progress of the reaction is different, which also causes non-uniform temperature distribution in the catalyst layer. Also, when fuel gas is introduced from below with the catalyst upper end inclined as described above, due to the pressure loss, the fuel gas easily flows into the lower upper end side, and more fuel gas is supplied. Inflow, the endothermic reaction is biased, and the temperature distribution of the catalyst layer becomes uneven.

The present invention has been made in view of the above problems, and has as its object to prevent the upper surface of the catalyst layer from being inclined due to the inclination of the reformer or the like and to reduce the difference in the temperature distribution of the catalyst layer. I do.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a first cylinder is provided on a periphery of the first cylinder at a predetermined distance from the first cylinder. A second cylinder, a top plate closing an upper end opening of the first tube, and a heating space surrounded by the top plate and the first tube. The upper end is extended upward, a catalyst layer through which fuel gas used for the reforming reaction passes is provided between the first cylinder and the second cylinder, and the upper surface of the catalyst layer is In the reforming tube below the top plate, a heat transfer particle layer is provided in a state of being stacked on the catalyst layer, the upper surface of the layer of the heat transfer particles is located above the top plate,
Further, a catalyst pressing plate is elastically urged on the heat transfer particle layer.

According to a second aspect of the present invention, there is provided the reformer having a partition tube, an inner tube provided inside the partition tube, and an outer tube provided outside the partition tube. The inner cylinder has a top plate, and a heating space is formed by the inner cylinder and the top plate.In a space surrounded by the partitioning cylinder and the inner cylinder, up to a position not reaching the top plate position. Filled with catalyst,
Further, the upper portion of the catalyst is filled with heat transfer particles up to the position above the top plate, and the pressing plate is elastically pressed by pressing means on the upper portion of the filled heat transfer particles as described above. I do.

According to a third aspect of the present invention, in the second aspect, the elastic pressing means is a metal spring. According to a fourth aspect of the present invention, in the second aspect, the heat transfer particles are at least one selected from silica, ceramics, and metal.

[0011]

According to the first and second aspects of the present invention, the following functions are provided. Due to the powdering of the catalyst, etc., the catalyst is denser than at the beginning of filling, even if the upper surface of the catalyst layer is lowered, since the heat transfer particles of the heat transfer particle layer provided on the catalyst layer have fluidity, It goes down smoothly with the movement of the upper surface of the catalyst layer. Therefore, there is no space between the catalyst layer and the heat transfer particle layer holding the catalyst layer. Further, since the pressing plate on the heat transfer particle layer is elastically urged by the elastic body, the catalyst layer is always held by the heat transfer particle layer and the pressing plate.

Further, since the temperature of the heat transfer particle layer is increased by the heat obtained from the heating space, the upper portion of the catalyst layer is kept warm by the heat transfer particle layer, thereby reducing the non-uniform temperature distribution of the catalyst layer. . In addition, when the fuel gas for the reforming reaction is supplied from above the catalyst layer, the fuel gas passes through the heat transfer particle layer and is supplied to the catalyst. Since the heat transfer particles of the heat transfer particle layer are heated by the heat from the heating space, the heat transfer particles apply heat to the fuel gas when the fuel gas passes. As a result, the fuel gas is supplied into the catalyst layer in a state where the temperature has been raised, thereby preventing a temperature drop above the catalyst layer.

Further, even if the wall of the cylinder on which the catalyst layer is provided expands and contracts due to the heat of the reforming reaction, and the upper surface of the catalyst layer moves up and down, the heat transfer particle layer and the holding plate are accordingly moved. Since the elastic body moves up and down and expands and contracts, the catalyst can be suppressed in response to expansion and contraction of the cylinder.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A reforming apparatus according to one embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a main part of a reforming apparatus according to the present embodiment. As shown in the figure, the reforming apparatus has a partition cylinder 1 and an inner cylinder 2 and an outer cylinder 3 arranged concentrically inside and outside thereof. The lower end is the inner cylinder 2 and partition cylinder 1
The space 4 formed by the outer cylinder 3 and the space 5 formed by the outer cylinder 3 and the partition cylinder 1 are connected to communicate with each other. Further, the opening at the upper end of the inner cylinder 2 is closed by a combustion chamber top plate 6. The outer cylinder 3 and the partition cylinder 1 are the inner cylinder 2
The upper ends of the outer cylinder 3 and the partitioning cylinder 1 are closed by a reformer top plate 7. At the center of the reformer top plate 7, there is provided a fuel gas inlet 8 composed of steam used for the reforming reaction and a raw material gas such as natural gas or methanol.
An outlet 9 for a reformed gas generated by a reaction in a catalyst layer 10 described later is provided in an upper portion of a side wall of the outer cylinder 3.

A catalyst layer 10 is provided in a space 4 formed by the partition cylinder 1 and the inner cylinder 2. However, the upper surface 10a of the catalyst layer 10 is provided below the position of the fuel quality top plate 6. At the lower end of the catalyst layer 10, a catalyst stopper 11 is provided from the lower end of the partition cylinder 1 to the inner cylinder 2 in order to hold the catalyst layer 10. On this catalyst layer 10, a heat transfer particle layer 12 is laminated. Upper surface 12 of heat transfer particle layer 12
“a” is higher than the fuel quality top plate 6. Further, a press plate 13 is elastically urged on the heat transfer particle layer 12 by a spring 14, and the heat transfer particle layer 12 is pressed toward the catalyst layer 10 by the spring 14 and the press plate 13. It is in a state. The holding plate 13 is provided with a hole 13a for passing fuel gas.
Further, the outer periphery of the pressing plate 13 is configured to be slightly smaller than the inner periphery of the outer tube 3 so that the inner surface of the outer tube 3 can be easily moved up and down in the outer tube.

A space 5 formed by the partition cylinder 1 and the outer cylinder 3 allows a reformed gas generated by a reforming reaction in the catalyst layer 10 to pass therethrough. In a space 15 surrounded by the inner cylinder 2 and the fuel quality top plate 6, a combustion cylinder 17 having a burner 16 below is provided. The combustion gas generated by the combustion of the burner 16 rises along the combustion cylinder 17, changes direction by the fuel quality top plate 6, passes around the inner cylinder 2 and the outer cylinder 3 of the reformer, and reforms. It is configured to raise the temperature of the tube. The temperature of the catalyst layer 10 and the heat transfer particle layer 12 is increased by the combustion gas.

The catalyst used in this embodiment has a particle size of Φ3
A sphere and a noble metal catalyst were used, and the packing density was 1 kg / liter. Further, as the heat transfer particles, silica-based particles having a diameter of 3 spheres and a packing density of 1 kg / liter were used. When the packing density of the catalyst is 1 kg / liter, the packing density of the heat transfer particles may be in the range of 0.9 to 1.1 kg / liter. (Experiment) The temperature distribution inside the catalyst and above the upper end of the catalyst when the reformer is operated after the reformer of this embodiment and the conventional reformer shown in FIG. The results are shown in FIG. 2 below. (Experimental conditions) The reformer was operated after being incorporated into the reformer system, and the temperature distribution was examined. When assembling the system, each reformer is tilted at least 45 degrees.

As shown in FIG. 3, a specific temperature measurement position in the catalyst is a position of H ₁ 20 mm upward from the lower end of the catalyst.
The temperature of the catalyst located approximately in the middle of the partition cylinder 1 and the inner cylinder 2 was measured at four points at an angle of 90 degrees in the circumferential direction of the cylinder (T ₁
~T _4). The measurement position above the upper end of the catalyst is H ₂ 100 mm downward from the reformer top plate 7 or the top plate 107.
The temperature of the location of, measured four angle 90 degree intervals in the circumferential direction of the tube (T ₅ ~T _8). The thicknesses of the inner cylinder, partition cylinder and outer cylinder of the reformer used for the measurement were each 2 mm.

As apparent from FIG. 2, the reforming of this embodiment
In the device, the inside of the catalyst layer (T₁~ T _FourThe temperature distribution at
It has been reduced. This is because the reformer of this embodiment
The catalyst unit does not tilt even if the
It is. Furthermore, the temperature above the catalyst layer (T_Five~ T₈)
In the reformer of this example,
And the difference from the inside of the catalyst is small.

This makes it difficult for heat above the filled catalyst to be taken away, thereby preventing a decrease in temperature above the catalyst. (Other matters) In order not to mix the catalyst particles and the heat transfer particles,
It is desirable to use particles having a similar particle diameter and specific gravity. The heat transfer particles are not limited to the above-mentioned silica, but may be ceramics or metal spheres as long as they have a gap that becomes a gas passage when filled and conduct heat. The heat transfer particles can be filled from a state where the top plate is hidden to a position where the spring can contract when the catalyst expands. In the above embodiment, the fuel gas used for the reforming reaction is supplied from above the catalyst layer, but may be supplied from below.

[0021]

As described above, according to the present invention, even if the upper surface of the catalyst layer moves downward due to the powdering of the catalyst, the heat transfer particles of the heat transfer particle layer move downward. ,
No space is formed between the catalyst layer and the heat transfer particle layer, the catalyst is always held down by the heat transfer particles, and the upper end of the catalyst does not tilt.

Further, the heat transfer particle layer heated by the heat from the heating space keeps the temperature of the catalyst layer or increases the temperature of the fuel gas supplied to the catalyst, thereby increasing the temperature of the upper part of the catalyst layer. The decrease is reduced, and the difference in the temperature distribution of the catalyst can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a reformer according to an example of the present invention.

FIG. 2 is a graph showing a temperature distribution of a reformer.

FIG. 3 is a diagram showing a temperature distribution measurement position.

FIG. 4 is a sectional view of a conventional reformer.

FIG. 5 is a diagram for explaining a problem of a conventional reformer.

FIG. 6 is a diagram for explaining a problem of a conventional reformer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Partition cylinder 2 Inner cylinder 10 Catalyst layer 12 Heat transfer particle layer 13 Press plate 14 Spring

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Katsuyuki Makihara 2-5-5 Keihanhondori, Moriguchi-shi Sanyo Electric Co., Ltd. (56) References JP-A-5-305229 (JP, A) JP-A Sho 63-21202 (JP, A) JP-A-6-40701 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01B 3/32-3/48 B01J 8/06 301

Claims (4)

(57) [Claims] 1. A first cylinder, a second cylinder provided on the outer periphery of the first cylinder at a predetermined distance from the first cylinder, and a ceiling closing an upper end opening of the first cylinder. A plate, and a heating space surrounded by the top plate and the first tube, and an upper end of the second tube extends upward from the top plate position,
A catalyst layer through which fuel gas used for the reforming reaction passes is provided between the first cylinder and the second cylinder, and the upper surface of the catalyst layer is lower than the top plate. In the tube, a heat transfer particle layer is provided in a state of being stacked on the catalyst layer, the upper surface of the heat transfer particle layer is located above the top plate, and further on the heat transfer particle layer A reformer characterized in that the catalyst holding plate is resiliently urged. 2. A reformer comprising: a partition tube; an inner tube provided inside the partition tube; and an outer tube provided outside the partition tube, wherein the inner tube is a top plate. A heating space is formed by the inner cylinder and the top plate, and a space surrounded by the partition tube and the inner cylinder is filled with a catalyst to a position not reaching the top plate position. Further, the heat transfer particles are filled to the upper part of the catalyst up to the position above the top plate, and the pressing plate is elastically pressed by the elastic pressing means on the heat transfer particles filled as described above. A reformer characterized by the above. 3. The reformer according to claim 2, wherein said elastic pressing means is a metallic spring. 4. The reformer according to claim 2, wherein the heat transfer particles are at least one selected from silica, ceramics, and metal.