JP2952407B2 - Fluidized bed reactor for hydrogen storage alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed reactor for performing a hydrogenation reaction of a hydrogen storage alloy and a dehydrogenation reaction of a hydrogenated hydrogen storage alloy.

[0002]

2. Description of the Related Art In a reactor having a fluidized bed of a hydrogen storage alloy (hereinafter, also simply referred to as an alloy), the alloy is filled on a dispersion plate of a single reaction vessel, and hydrogen gas is supplied from under the dispersion plate. Has been proposed in which all the alloy is fluidized in one container by ventilating the same.
No. 00). However, in the case of a hydrogen storage alloy, its hydrogenation reaction (hydrogen storage) and dehydrogenation reaction (hydrogen release)
Each time is repeated, the powdery alloy gradually becomes finer and becomes a fine powder having a cohesive property of about 10 μm in diameter, which is difficult to fluidize. Therefore, it is very difficult to form a uniform fluidized bed having good reactivity. Yes, this causes various problems. One of such problems is that a channeling phenomenon occurs in the fluidized bed, making it difficult to form a uniform fluidized bed. FIG. 4 shows a schematic view of a fluidized bed in which a channeling phenomenon has occurred. In FIG.
2 indicates a dispersion plate, and F indicates a fluidized bed of the alloy formed thereon. C indicates a channel generated in the fluidized bed.
The fluidized bed F shown in FIG. 4 is formed by the wind pressure of the hydrogen gas ejected upward from below the dispersion plate 2.
In this case, when the ratio H (F) / D (F) of the height H (F) of the fluidized bed to the diameter D (F) of the fluidized bed is small (usually,
When it is less than 1), the channel C is easily generated in the fluidized bed F. When a channel is generated, a part of the hydrogen gas flows through the channel without contacting the alloy.

According to the study of the present inventors, the problem of the occurrence of channeling is that in the case of a fluidized bed of an alloy, its diameter D
The ratio of the height H (F) to (F) H (F) / D
It has been found that the problem can be solved by setting (F) to 1 or more, preferably 2 or 3 or more. That is, H (F) /
When D (F) is 1 or more, a stable and uniform alloy fluidized bed can be obtained without causing the above-described channeling. However, increasing the H (F) / D (F) ratio has the advantage that the required hydrogen gas flow rate can be reduced with the same amount of alloy, but the pressure for sending hydrogen gas increases, so that the differential pressure Requires the use of a large compressor, which is not practical. In addition, hydrogenation and dehydrogenation of the alloy generate a large amount of heat and heat absorption, and in order to speed up the reaction, arrange many heat transfer tubes in the alloy layer,
The heat of reaction generated by the hydrogenation of the alloy must be quickly removed, while the amount of heat required for the reaction must be quickly supplied for the dehydrogenation of the alloy. However, the arrangement of the heat transfer tubes in the alloy fluidized bed hinders the smooth formation of the alloy fluidized bed and causes a problem of wear of the electric heating tube itself.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to a fluidized bed reactor having a fluidized bed formed by fluidizing a hydrogen storage alloy with hydrogen gas without using a compressor having a large differential pressure. In addition to providing an alloy fluidized bed reactor that enables the formation of a stable alloy fluidized bed without channeling, hydrogenation of the alloy and hydrogenation of the hydrogenated alloy can be performed without disposing a heat transfer tube in the alloy fluidized bed. An object of the present invention is to provide a fluidized bed reactor for an alloy capable of promptly performing a dehydrogenation reaction.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, there is provided a fluidized bed reactor for a hydrogen storage alloy for performing a hydrogenation reaction of the hydrogen storage alloy and a dehydrogenation reaction of the hydrogenated hydrogen storage alloy,
Chamber and a hydrogen storage alloy discharge mechanism, and the fluidized bed chamber has a plurality of
It consists of small-scale fluidized bed chambers and each small-scale fluidized bed.
The height H (F) of the fluidized bed formed in the bed chamber and the height of the fluidized bed
The ratio H (F) / D (F) to the cross sectional equivalent diameter D (F) is 1
And the hydrogen storage alloy discharging mechanism has a tip
Open in the space above the small-scale fluidized bed chamber or
Discharge of the alloy opening to the dispersion plate surface forming the bottom plate of the fluidized bed chamber
Connecting pipe, alloy storage room, alloy discharge tube and alloy storage room
And a fluidized bed reactor for hydrogen storage alloy, comprising:

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As the hydrogen storage alloy in the present invention, various conventionally known alloys can be used.
Such materials include, for example, LaNi ₅ , LaN
i5 _- xAlx, MmNi5 _- xAlx (Mm: Michelle metal) and the like. The average particle size of the alloy when charged into a fluidized bed reactor is usually about 40 to 50 μm. If the initial particle size at this level, it is possible to maintain a particle size of about 10μm also to the use of 10 ⁴ cycles.

[0007] The fluidized bed reactor for a hydrogen storage alloy according to the present invention is characterized in that the fluidized bed is constituted by a plurality of small-scale fluidized bed chambers. FIG. 1 shows a fluidized bed reactor 1 of the present invention.
FIG. 3 shows a schematic diagram of one embodiment. FIG. 2 shows an XY sectional view of the fluidized bed reactor shown in FIG. 1 and 2, 1 is a fluidized bed reactor, 2 is a dispersion plate, 3 is a dust filter, 4- (af) is a small fluidized bed chamber, 5 is an alloy discharge pipe, 6 is a heat transfer pipe. , 7 is an alloy storage room,
8 is a rotary valve, 9 is an alloy storage room, and 10- (a to
f) indicates an alloy distribution pipe, 11 and 12 indicate peripheral walls, 13 and 14 indicate alloy conduits, and 22 indicates a compressor. Fluidized bed chamber 4- (a ~
Each of f) has peripheral walls 11 and 12 (12 is also a partition of a fluidized bed chamber), and the inside is formed in a space. Each of these fluidized bed chambers is arranged in parallel on its dispersion plate 2 in the fluidized bed reactor 1. Dispersion plate 2
Has a large number of through-holes, and allows hydrogen gas for fluidizing the alloy filled in each fluidized bed chamber to flow upward. The through-holes of the dispersion plate 2 are arranged at the upper part thereof. It is formed only in the portion corresponding to the bottom of the provided fluidized bed chamber.
That is, when the hydrogen gas flows upward from below the dispersion plate 2, the hydrogen gas is blown up only in each fluidized bed chamber. As shown in FIGS. 1 and 2, the shape of each fluidized bed chamber is formed in a hexagonal cylinder having a transverse section, but the shape of the fluidized bed chamber is not limited to this. Its cross section is triangular, quadrangular,
It may be a rectangular cylinder of any shape such as a pentagonal shape, an octagonal fan shape, or the like, and may be a cylinder having a circular or elliptical cross section, or a combination thereof. .

[0008] The fluidized bed reactor of the present invention has a supply mechanism for the alloy to be subjected to the reaction treatment and a discharge mechanism for the alloy subjected to the reaction treatment, similarly to the conventional apparatus. In the case of the present invention, the alloy supply mechanism comprises an alloy storage chamber 7, a rotary valve 8, an alloy conduit 13, and an alloy distribution pipe 10- (af), and the tip of each alloy distribution pipe 10- (af). Is located in each fluidized bed chamber. On the other hand, the alloy discharge mechanism includes an alloy discharge pipe 5, an alloy conduit 14, and an alloy storage room 9. In the case of the apparatus shown in FIGS. 1 and 2, the alloy discharge pipe 5 has a tip end opening above the center of the apparatus, but the alloy discharge pipe is not necessarily limited to such a structure. Alternatively, the distal end of the alloy discharge pipe can be opened on the surface of the dispersion plate forming the bottom plate of each fluidized bed chamber. Also, the number of alloy discharge pipes is not limited to one,
There may be more than one.

In order to carry out a hydrogenation reaction of an alloy using the apparatus of the present invention, first, an alloy to be subjected to a reaction treatment is filled into each fluidized bed chamber 4- (a to f) by an alloy supply mechanism. Next, hydrogen gas is introduced into the apparatus space A below the dispersion plate 2 through the line 15, the valve 16, and the line 17, and from there, the hydrogen gas is passed through the dispersion plate 2 upward, and each of the fluidized bed chambers 4- (a to f). Blow up). Thereby, the alloy filled in each fluidized bed chamber is fluidized by the wind pressure of the hydrogen gas, and a fluidized bed F is formed. The hydrogen gas after the alloy has been blown up and fluidized enters the upper space B of the apparatus, from which it is extracted to the outside of the apparatus through the dust filter 3, passed through the lines 18 and 21, and passed through the compressor 22. , Where the pressure is raised to the pressure required for fluidized bed formation, circulated through line 17 and fed again to the apparatus. From the line 15, the hydrogen gas consumed for hydrogenation of the alloy is supplied. In the hydrogenation reaction of this alloy, the valve 20 is closed.

[0010] As described above, hydrogenation of the alloy is achieved by circulating the hydrogen gas and blowing up and fluidizing the alloy with the hydrogen gas. That is, the alloy is
In flow, it comes into contact with hydrogen gas, whereby hydrogenation of the alloy is achieved. In this case, the heat generated by the hydrogenation of the alloy is absorbed by the cooling medium passing through the heat transfer tube 6 and discharged to the outside, whereby the fluidized bed chamber is maintained at a predetermined hydrogenation temperature. In this case, the pressure in the device is maintained at the hydrogenation reaction pressure by adjusting the pressure in the device. As the cooling medium, besides the cooling water, an organic liquid or the like can be used. Next, after the hydrogenation reaction of the alloy is completed, the valve 16 is closed, the compression pressure of the compressor 22 is increased to increase the hydrogen gas pressure, and the velocity of the hydrogen gas blown upward from the dispersion plate 2 is increased by a fluidized bed. The speed is higher than that required for formation, which causes the alloy to be blown into the headspace B of the device. Since the alloy blown up into the space B does not blow up hydrogen gas from the opening of the discharge pipe 5,
It falls into the opening of the discharge pipe 5, and the discharge pipe 5 and the conduit 14
And enters the alloy storage room 9 to be stored.

On the other hand, when the hydrogenated alloy is subjected to a dehydrogenation reaction using the apparatus of the present invention, the hydrogenated alloy is supplied from the alloy storage chamber 7 to the rotary valve 8, the conduit 13, and the distribution pipe 10-. Fill each fluidized bed chamber through (af). Thereafter, the alloy is blown up and fluidized as in the case of hydrogenation of the alloy. In this case, a heat medium is circulated through the heat transfer tube 6 to heat the hydride alloy and maintain the same at a predetermined dehydrogenation reaction temperature. In this case, the pressure in the device is adjusted to maintain the pressure in the device at the dehydrogenation reaction pressure. As the heat medium, an organic liquid or the like can be used in addition to heated water or steam. After the completion of the dehydrogenation reaction, the dehydrogenated alloy is introduced into the alloy storage chamber 9 through the discharge pipe 5 and the conduit 14 and stored in the same manner as described above.

FIGS. 1 and 2 show a method using a heat transfer tube 5 disposed in a fluidized bed chamber as a cooling and heating method for maintaining the alloy at its reaction temperature. Arrangement of the heat transfer tube in the room is not preferable because it hinders fluidization of the alloy and causes contact abrasion of the heat transfer tube due to bubbling of the alloy particles. In the case of the present invention, a communication hole is formed inside the peripheral walls 11 and 12 of the fluidized-bed chamber, and this communication hole is used as a passage for the cooling medium or the heat medium, and the cooling medium or the heat medium flows through the communication hole. Thus, the temperature in the fluidized bed chamber can be controlled.

FIG. 3 shows a cross-sectional view of an apparatus having a fluidized-bed chamber formed by a peripheral wall having a communication hole formed inside the wall. In FIG. 3, reference numeral 25 denotes a communication hole formed inside the peripheral wall. In the fluidized-bed chamber having the peripheral walls 11 and 12 shown in FIG. 3, the peripheral walls 11 and 12 are formed of a material having good thermal conductivity, and generally have a thermal conductivity of 10 kcal / m.
-It is formed of a material of h · ° C or higher. Examples of such a material include a metal material such as iron, stainless steel, a titanium alloy, and an aluminum alloy, and a carbon material such as graphite. In this case, the thickness of the peripheral wall is about 10 to 30 mm, the size of the communication hole is smaller than the thickness of the peripheral wall, and the hole diameter is usually about 5 to 20 mm. Further, in the case of the present invention, the peripheral wall may be configured by arranging a plurality of heat transfer tubes between two plate members having good heat conductivity and forming the whole in one plate shape. it can. Further, the peripheral wall may have a structure in which a heat transfer tube is joined with a plate material. An example is shown in FIG. In FIG. 5, 31 indicates a heat transfer tube, and 32 indicates a plate. As the plate member 32, a metal plate or the like having good heat conductivity is used, and a thin plate having a thickness of about 5 mm is sufficient.

In the case of the fluidized bed reactor of the present invention, the ratio h / D (I) of the height h of the peripheral wall of the fluidized bed chamber to the equivalent diameter D (I) of the one fluidized bed chamber is 1 or more; Usually 1
4, preferably 2 to 4. The equivalent diameter D (I) of each of the fluidized bed chambers is usually 10 in a commercial scale apparatus.
-40 cm, preferably 20-30 cm, and the height h of the peripheral wall is 20-80 cm. Also, its D
The ratio h / D (I) of h to (I) is in the range of 1-4, preferably 2-4. On the other hand, the equivalent diameter D in the device surrounding these small fluidized bed chamber groups
The ratio h / D of the height h of the peripheral wall of the fluidized bed chamber to (II)
(II) is not particularly limited. The equivalent diameter D of the fluidized bed chamber means its diameter when the cross-sectional area S of the fluidized bed chamber is converted into a circular area, and is expressed by the following equation. D = (4S / n) ^1/2 (1)

In the apparatus of the present invention, the height H (F) of the fluidized bed formed in the fluidized bed chamber is determined with respect to the equivalent diameter D (F) or D (I) of the fluidized bed (fluidized bed chamber). The ratio H (F) / D (F) of the fluidized bed height H (F) is 1 to 4,
Preferably, it is designed to be 2 to 4. H (F) / D
By defining (F) in such a range, the fluidized bed of the alloy can be smoothly formed in each fluidized bed chamber without particularly increasing the differential pressure of the compressor. A fluidized bed in which the ratio of the height H (F) of the fluidized bed to the equivalent diameter D (II) of the device is 1 or more is formed in the apparatus without using the small-scale fluidized bed chamber as described above. In this case, in this case, since the equivalent diameter of the device is significantly larger than the cross-sectional area of the small-sized fluidized-bed chamber used in the present invention, the height H (F) is the same as that of the fluidized-bed of the fluidized-bed chamber. The hydrogen gas blow-up speed required to form the fluidized bed is significantly high, and accordingly, it is necessary to increase the differential pressure of the compressor.

[0016]

According to the fluidized bed reactor for an alloy of the present invention, which includes a plurality of small-sized fluidized bed chambers disposed inside the apparatus, the fluidized bed chamber is small (equivalent diameter is small) and the fluidized bed is small. , The height H (F) of the fluidized bed formed in each fluidized bed chamber and the equivalent diameter D of the fluidized bed
The ratio of H (F) / D (F) to (F) is set to 1 or more, preferably, at which the channeling phenomenon does not occur at a low rising rate of hydrogen gas (normally 0.05 to 0.3 m / sec), preferably It becomes possible to hold two or more. As a result, the differential pressure of the compressor for increasing the pressure of hydrogen gas can be low,
The compressor may be small and very advantageous in terms of energy. Further, the apparatus of the present invention in which the passage of the cooling medium or the heat medium is arranged inside the peripheral wall of the fluidized bed chamber does not hinder the fluidization of the alloy at all, and therefore smoothly fluidizes the alloy. be able to. The fluidized bed reactor for the alloy of the present invention is a device for hydrogenating and dehydrogenating an alloy when hydrogen is stored or released in the alloy, a hydrogen recovery device for selectively absorbing and separating hydrogen from a mixed gas, It is advantageously used as an apparatus for hydrogenating or dehydrogenating an alloy in various heat pumps or refrigerators using an absorbing alloy and hydrogen.

[Brief description of the drawings]

FIG. 1 is a schematic view of a fluidized bed reactor for an alloy of the present invention.

FIG. 2 shows an XY cross section of the device of FIG.

FIG. 3 is an XY cross-sectional view in the case where a peripheral wall having a passage for a cooling medium or a heat medium inside the wall is used as the peripheral wall of the fluidized bed chamber in the apparatus shown in FIG.

FIG. 4 is a schematic view of a fluidized bed in which a channeling phenomenon has occurred.

FIG. 5 shows a structural diagram for an example of a peripheral wall.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluidized bed reaction apparatus 2 Dispersion liquid 3 Dust removal filter 4- (a-f) Fluidized bed room 5 Alloy discharge pipe 6 Heat transfer tube 7,9 Alloy storage room 8 Rotary valve 10- (a-f) Alloy distribution pipe 11,12 Peripheral wall 13, 14 Alloy conduit 22 Compressor 25 Passage of cooling medium or heat medium 31 Heat transfer tube 32 Plate

──────────────────────────────────────────────────の Continued on the front page (73) Patent holder 000001889 Sanyo Electric Co., Ltd. 2-5-1-5 Keihanhondori, Moriguchi-shi, Osaka (74) The above four agents Patent Attorney Toshiaki Ikeura (72) Inventor Aizawa Kazuo 2-8-11 Nishi-Shimbashi, Minato-ku, Tokyo 7th Oriental Maritime Building 8th Floor, Institute for Global Environmental Technology, CO2 Fixation Project Room (72) Inventor Chika Inazumi 2-Nishi-Shimbashi, Minato-ku, Tokyo 8-11 7th Oriental Maritime Building 8th Floor Project Room for CO2 Fixation, etc. (72) Inventor Yumiko Nakamura 2-8-11 Nishishinbashi, Minato-ku, Tokyo 7th Oriental Maritime Building 8 Floor: Research Institute for Innovative Technology for the Earth, CO2 Fixation Project Room (72) Inventor Keisuke Oguro 1-8 Midorioka, Ikeda-shi, Osaka No. 31 Inside the Osaka Institute of Technology (72) Inventor Hitoshi Uehara 1-81-31 Midorioka, Ikeda-shi, Osaka Prefecture Examiner at the Osaka Institute of Technology Institute Jun Sano (56) References JP 62 -241801 (JP, A) JP-A-61-83867 (JP, A) JP-B-42-26161 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) F17C 11/00 B01J 8/26 C01B 3/00 F27B 15/00

Claims (2)

(57) [Claims] 1. A fluidized bed reactor for a hydrogen storage alloy for performing a hydrogenation reaction of a hydrogen storage alloy and a dehydrogenation reaction of a hydrogenated hydrogen storage alloy , comprising: a fluidized bed chamber;
The fluidized bed chamber has a plurality of small fluidized bed chambers.
And the flow formed in each small-scale fluidized bed chamber.
The height H (F) of the moving bed and the equivalent cross-sectional diameter D of the fluidized bed
The ratio H (F) / D (F) to (F) is 1 or more, and
The tip of the hydrogen storage alloy discharge mechanism has the tip of the small-scale fluidized bed.
Or open the bottom plate of a small fluidized bed chamber
An alloy discharge pipe opening on the surface of the dispersion plate to be formed, and an alloy storage room
And an alloy conduit connecting the alloy discharge pipe and the alloy storage room.
Fluidized bed reactor of the hydrogen-absorbing alloy, characterized in that Ranaru. 2. The apparatus according to claim 1, wherein the peripheral wall of each small-scale fluidized bed chamber is made of a material having good heat conductivity, and a communication hole or a heat transfer tube is disposed inside the peripheral wall.