JPS63310703A - Methanol reforming device - Google Patents

Abstract

PURPOSE:To renew the catalyst packing density which becomes coase due to the reduction operation to be dense and to prevent the generation of particles of catalyst by providing a catalyst pressing mechanism pressing the catalyst through a pressing plate which is permeable for the reforming gas, to the end surface of reforming gas outlet side of reforming catalyst layer in a cylindrical vessel. CONSTITUTION:In the heated state of an evaporator 17 and a reactor 6, the reforming raw material consisting of methanol and water is supplied from an inlet 18 in the direction shown by an arrow 25, and evaporated at the evaporator 17, and the evaporated gas is sent through a raw material manifold 19 to a raw material gas inlet 6a of the lower end part of the reactor 6. This raw material gas is brought into contact with the catalyst 10 while ascending in the reactor 6 to be reformed. Before the reforming device is put into operation, the reduction operation for the catalyst 10 is carried out and the volume of the catalyst is reduced with the result that the packing density of the catalyst 10 becomes coase. Therefore, the upper end surface of catalyst layer is gradually pressed down by the pressing plate 22 and the packing density of the catalyst 10 is raised, and the fluidization of the catalyst 10 and the grinding of the catalyst 10 due to the movement of reforming device are restrained.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a methanol reformer that catalytically reacts methanol with a catalyst in the presence of water vapor to reform it into a gas containing hydrogen as a main component to be supplied to a fuel cell.

[Conventional technology]

Fuel cells are attracting attention as a new power source. This fuel cell is a system that supplies hydrogen and air (oxygen) to a hydrogen electrode and an air electrode placed between an electrolyte, respectively, and generates electricity using the opposite principle to water electrolysis. Steam reforming of methanol is a means for obtaining hydrogen to be supplied to such fuel cells. This is a method in which methanol is brought into contact with a catalyst in the presence of water vapor to reform it into a gas containing hydrogen as its main component, and the reaction formula at this time is as follows. CH30H+H,O→Cot +3 Hz In addition, the reforming catalyst used in this case is Cu-Zn type, Cu-
Zn-Cr type, Cu-Zn-At type, Cu-Cr type, etc. are known. By the way, these reforming catalysts are filled into a reformer in an oxide state before use, but participate in the above-mentioned reforming reaction in a reduced state. If you start operating the reformer with the reforming catalyst in an oxide state, the reduction reaction of the catalyst will generate an extremely high amount of heat, and as a result, the catalyst itself will be heated above its limit temperature and deteriorate. , the reactor containing the catalyst may be damaged. For this reason, the reforming catalyst is normally subjected to a reduction operation as a preliminary step before the reformer starts operating, and then the reforming operation is started. Now, the reaction of this reduction operation, for example in the case of a copper-based catalyst, is as follows. CuO+H2-+Cu+H2O As can be seen from this reaction formula, the volume of the catalyst decreases due to the reduction operation. Therefore, the packing density of the catalyst packed in the reactor of the reformer becomes coarse due to this reduction operation.

[Problems to be solved by the invention]

When the catalyst packing density in the reactor becomes coarse, the catalyst tends to flow due to the raw material gas during operation of the reformer (this reduces the contact efficiency between the raw material gas and the catalyst. Furthermore, due to this catalyst flow, In addition, in small fuel cells used as a mobile power source, vibrations during transportation cause the catalyst to shatter, producing a large amount of catalyst fine powder and reducing the performance of the catalyst. As a countermeasure, the catalyst was reduced in advance to reduce its volume, and then only the surface was oxidized to protect the internal reduction layer.
It is conceivable to use a uced type catalyst. However, this type of catalyst suffers from high cost. This invention was made under the above circumstances, and in response to the volume reduction when the catalyst is reduced while packed in a reactor, the coarse packing density of the catalyst is restored to a denser one. The object of the present invention is to provide a methanol reformer that can prevent catalyst flow during operation of the reformer and generation of catalyst fine powder during movement of the reformer.

[Means to solve problems] This invention provides a methanol reformer having a reactor in which a cylindrical container is filled with a reforming catalyst, one end of which serves as an inlet for raw material gas, and the other end serves as an outlet for reformed gas. A catalyst pressing mechanism is provided that presses the reformed gas outlet side end face of the reformed catalyst layer via a reformed gas permeable push plate. [For use]

According to this invention, even if the catalyst packing density becomes coarse due to the catalyst reduction operation, the reforming catalyst layer is compressed by being pressed, and the catalyst packing density is increased again. Further, since the press plate that presses the end face of the reforming catalyst layer is permeable to the reformed gas, it does not affect the passage of the reformed gas.

【Example】

In FIG. 1, reference numeral 1 denotes a cylindrical furnace body with a garden, which is closed by a disc-shaped lid plate 2. A burner 3 for heating the inside of the furnace is attached to the inner center of the lid plate 2. 4 is its fuel gas supply pipe, 5
is the combustion air supply pipe. Inside the furnace body 1, a reactor 6 is provided surrounding the burner 3. This reactor 6 is constructed by filling a reforming catalyst 10 into a cylindrical container consisting of a cylindrical inner tube 7, an outer tube 8, and an annular bottom plate 9 that are arranged concentrically. The inner cylinder 7 of the reactor 6 is in contact with the outer periphery of the burner 2 and is fixed at the upper part so as to be suspended from the lower surface of the lid 2. The inside of this inner cylinder 7 serves as a combustion chamber 11 of the burner 2. The outer cylinder 8 forms a combustion gas passage 12 with an annular cross section between it and the furnace body 1, and is fixed to the inner wall surface of the furnace body 1 at an upper flange portion. A combustion gas outlet 1 is provided at the upper part of the combustion gas passage 12.
3 is provided. The bottom plate 9 of the reactor 6 faces the bottom plate 1a of the furnace body 1 with a gap therebetween, and this gap forms a circular combustion gas manifold 14 that communicates the combustion chamber 11 and the combustion gas passage 12. . Further, an annular reformed gas manifold 15 is formed above the reactor 6, and a reformed gas outlet pipe 16 is provided in M2 so as to communicate with this reformed gas manifold 15. A reforming material vaporizer 17 is arranged in the combustion chamber 11 so as to be located below the burner 2 . The vaporizer 17 is a spirally wound pipe that rises vertically upward from the reformed raw material inlet 17a, then descends in a spiral fashion, and further descends vertically from the middle to end at the raw material gas outlet 1'7b. There is. The reformed raw material inlet 17a of the vaporizer 17 is connected to the reformed raw material supply pipe 1.
8, and the source gas outlet section 17b is connected to the source gas manifold 19. The raw material gas manifold 19 is tubular and crosses the combustion chamber 11, connecting the right half and the left half of the annular space in the reactor 6 in FIG. As will be described later, the lower end of the reactor 6 is the inlet 6 for the raw material gas.
a, and the upper end becomes the reformed gas outlet 6b. Now, on the reformed gas outlet side of the reactor 6, a catalyst pressing mechanism 21 for pressing the end surface 20 of the catalyst layer is provided. This catalyst pressing mechanism 21 consists of a reformed gas permeable annular pressing plate 22 that contacts the end face 20 of the catalyst layer, and a compression spring 23 provided between this pressing plate 22 and the cover plate 2. . The details are shown in FIGS. 3 and 4. Four springs 23 are provided (Fig. 4), and their upper ends are attached to the cover plate 2.
The lower end is connected to a push plate 22. The push plate 22 is made of a porous material, such as foamed metal, so as to allow the reformed gas to pass therethrough. The cover plate (Fig. 3) to which the catalyst pressing mechanism 21 is attached is
When the push plate 22 is inserted into the reactor 6 filled with the catalyst 10 and attached to the furnace body 1 as shown in FIG. be done. Now, the methanol reformer configured as described above reformes the gas supplied from the reforming raw material supply pipe 18 under combustion in the burner 2 into a gas mainly composed of hydrogen as follows. This reformed gas is supplied from the reformed gas outlet pipe 16 to a hydrogen electrode of a fuel cell (not shown). The combustion gas of the burner 3 flows into the combustion chamber 11 as shown by the arrow 24.
The raw material gas passes through the front and rear sides of the raw material gas manifold 19 in FIG. In this process, the vaporizer 17
And the reactor 6 is heated by heat transfer in contact with the combustion gas. Further, the vaporizer 17 is simultaneously heated by the radiant heat from the burner 3. With the vaporizer 17 and the reactor 6 heated in this manner, when a reforming raw material consisting of methanol and water is supplied from the reforming raw material supply pipe 18 as shown by the arrow 25, this reforming raw material is vaporized. The raw material gas population 6a is evaporated and gasified in the reactor 17, and passes through the raw material gas manifold 19 to the lower end of the reactor 6.
reach. This raw material gas rises through the annular space in the reactor 6 while contacting the catalyst 10, and is reformed according to the reaction formula described above. This reformed gas is collected into a reformed gas manifold 15 from a reformed gas outlet 6b in the upper part of the reactor 6, and is supplied to the fuel cell from a reformed gas outlet pipe 16. Prior to such operation of the reformer, the catalyst 10 is reduced as described above. At this time, when the volume decreases and the packing density of the catalyst becomes coarse, the catalyst layer is gradually compressed by the pressing force applied to its upper end surface, and the surface of the catalyst layer descends as shown in FIG. As a result, the packing density of the catalyst is increased, and pulverization of the catalyst due to the flow of the catalyst due to the upward flow of the raw material gas and vibrations during movement of the reformer is suppressed. The magnitude of the pressing force by the spring 23 is appropriately selected in consideration of internal friction of the catalyst layer so as to obtain a desired catalyst density. In addition, the metal foam in the push plate also acts as a filter,
It also has the effect of collecting catalyst fine powder that scatters during operation and preventing it from reaching the fuel cell itself. As the pressing means of the catalyst pressing mechanism, in addition to springs such as coil springs or leaf springs in the illustrated embodiment, hydraulic pressure, pneumatic pressure, etc. can also be used. Also, as in the illustrated embodiment,
In addition to a method in which the pressing force is applied constantly, a method in which the pressing force is applied temporarily after the reduction operation of the catalyst is also conceivable.

【Effect of the invention】

According to this invention, since a pressing mechanism is provided that presses the end face of the reformed gas outlet side of the reformed catalyst layer through the reformed gas permeable push plate, the volume of the catalyst is reduced due to the reduction operation of the catalyst. Even when the packing density becomes coarse, the catalyst bed can be compressed to increase the packing density, and this can prevent catalyst flow during reformer operation caused by a decrease in catalyst packing density, or during transportation of the reformer. Inconveniences such as generation of catalyst fines can be avoided.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the reformer of the present invention, FIG. 2 is a longitudinal sectional view of the reformer showing a state in which the catalyst layer surface is lowered in FIG. FIG. 4 is a side view showing the catalyst pressing mechanism, and FIG. 4 is a bottom view of FIG. 3. 6: Reactor, 6a: Raw material gas inlet of the reactor, 6b: Reformed gas outlet of the reactor, 10: Reforming catalyst, 21: Catalyst pressing mechanism, 22: Push plate. Figure 1 Figure 2 22J Machine Torture Figure 3 2311'' Figure 4

Claims (1)

[Claims] 1) In a methanol reformer having a reactor in which a cylindrical container is filled with a reforming catalyst and one end of the container serves as an inlet for raw material gas and the other end serves as an outlet for reformed gas, reforming is carried out in a methanol reformer. A methanol reformer comprising a catalyst pressing mechanism that presses the end face of the catalyst layer on the reformed gas outlet side via a reformed gas permeable push plate.