JPH0121949Y2 - - Google Patents

Description

[Detailed explanation of the invention] Industrial application field This invention is a hydrogen recovery and
Regarding purification containers.

BACKGROUND ART Metal hydrides (hereinafter referred to as MH) absorb and desorb large amounts of hydrogen, so they can be used in hydrogen gas recovery devices that store hydrogen gas and use it as needed. In addition, since MH has a selective hydrogen absorption property, when hydrogen gas containing impurities is brought into contact with MH fine powder, only hydrogen is absorbed, and the impurities are concentrated in the hydrogen gas remaining in the spaces between the MH fine powder. After purging this hydrogen gas, the hydrogen occluded in MH is devolatilized to obtain highly pure hydrogen gas. By repeating this process in multiple stages, conventional hydrogen purification methods such as the PSA method can It is possible to obtain high purity hydrogen (for example, 7×N, 9×N) that is higher than the limit.

By the way, the hydrogen absorption reaction of MH is rate-limited by the surface reaction, so in the above-mentioned hydrogen recovery and purification equipment using MH, MH is crushed into fine powder and filled into the container, so about half the volume of the container is used. remains as a void between the MH particles (MH is not spherical, but
For example, the volume of a sphere is 0.52 times the volume of a cube whose side is its diameter. ), therefore, purging the gas containing many impurities remaining in that area has a large effect on hydrogen purification efficiency.

MH is pulverized into smaller particles through repeated hydrogen absorption and devolatilization, and a so-called consolidation phenomenon occurs where the smaller particles gather at the bottom of the container and the larger particles float upward. To prevent this phenomenon,
The MH holding container for hydrogen recovery and purification is generally horizontal as shown in FIGS. 3 and 4. In the apparatus shown in FIG. 3, a cylindrical inner container 2 is provided within a cylindrical outer container 1, and the inside thereof serves as a space 3 for holding fine powdered MH. In this space, a hydrogen gas flow pipe 4 having an air-permeable wall is provided in the longitudinal direction, and hydrogen gas is taken in and out from one end thereof. A heat exchange fluid passage 5 is formed between the inner container 2 and the outer container 1, and the heat of reaction during hydrogen absorption and devolatilization is transferred to the heat exchange fluid through the wall of the inner container.

In the apparatus shown in FIG. 4, a hydrogen gas pipe 12 having a permeable wall is provided on the center line of a horizontal cylindrical container 11, connected to an external hydrogen gas pipe 13, and a MH holding space is provided between the pipe 12 and the container 11. 14, in which a heat exchange fluid pipe 15 is provided in a coil shape surrounding the hydrogen gas pipe 12.

Problems that the present invention aims to solve By arranging the container horizontally as described above, it is easier to prevent the compaction phenomenon, but when purging hydrogen gas containing a large amount of impure gas, the hydrogen gas In order to exhaust the gas between the MH through the pipes 4 and 12, the upper part 3a of the MH holding space 3 and 14,
It is structurally difficult to exhaust the gas in the portion 14a. Therefore, it is necessary to forcibly exhaust the air with an ejector or pump, and in that case, the MH
In order to minimize the release of hydrogen from the container and
It is common practice to cool the MH, which has led to high costs.

Purpose of the present invention The present invention eliminates the above-mentioned drawbacks of conventional hydrogen recovery and purification equipment using MH, and allows easy purging of gas containing many impurities in the MH holding space.
In addition, expansion and contraction due to hydrogen gas absorption and devolatilization of MH can be easily released, which allows the container and
The object of the present invention is to provide a hydrogen recovery/purification container that does not generate harmful stress on MH and prevents compaction of pulverized MH.

Means for Achieving the Object In order to achieve the above object, the present invention provides an elongated cylindrical container in which a metal hydride holding space is formed on the inside and a heat exchange fluid flow path is formed on the outside or inside the metal hydride holding space. In the hydrogen recovery/purification vessel having a hydrogen gas distribution pipe extending longitudinally within the metal hydride holding space and having a vent hole in the pipe wall, the long cylindrical container is installed vertically, and the metal hydride is The mixture is made into a fine powder and sandwiched between upper and lower felt layers in a holding tray consisting of a rising part that fits into the inner surface of the container and a bottom plate with a hole through which the hydrogen gas flow pipe can pass. A plurality of holding plates holding metal hydrides are stacked and loaded into the container, and the vent hole in the pipe wall of the hydrogen gas distribution tube is in the range of the thickness of the lower felt layer in the holding plate. It is also characterized in that one of the tube end openings of the hydrogen gas flow tube is provided in a felt layer above the metal hydride layer of the uppermost holding tray.

For a hydrogen recovery/purification container having the above characteristics, it is preferable to introduce hydrogen gas from the bottom and release it from the top.

Function The hydrogen recovery/purification container of the present invention has the following properties as described above.
The container containing MH is installed vertically, and a hydrogen gas distribution pipe runs through it in the longitudinal direction.
When purging hydrogen gas containing impure gas, there is no part that is separated above the hydrogen gas flow pipe and makes gas processing difficult, and the gas between the MH particles can be purged using, for example, the internal pressure of the container. This can be done with simple operations such as gas blowing.

In addition, MH was made into fine particles and held in a holding tray with layers of breathable and elastic felt layers sandwiched between the upper and lower sides, and multiple pieces of this were stacked and loaded into the container, so that hydrogen absorption and desorption of MH was prevented. It is possible to easily follow the volume change of MH due to storage, and there is no excessive stress or voids in the MH holding tray or container, and therefore the MH is further crushed into fine powder. It is possible to avoid the occurrence of a compaction state, which reduces the amount of hydrogen storage and generates harmful forces in the container.

Since the MH holding plates are stacked and loaded loosely into the container, if hydrogen gas is introduced into the container from the bottom of the container and discharged from the top, the hydrogen gas will flow through the hydrogen gas distribution pipe. It easily enters the MH fine powder layer from the wide upper surface of the MH holding dish through the felt on the lower side of the inside of the MH holding dish through the vent hole drilled in the tube wall, and reacts with all the MH. When purging impurity-containing gas and releasing devolatilized hydrogen gas, the gas not only passes through the lower felt layer, enters the hydrogen flow pipe through the vent, rises therein, and is released. It passes through the felt layer above the MH fine powder layer, and connects each gap between the holding plates stacked one above the other, between the outer peripheral surface of the holding plate and the inner surface of the container, and between the hole in the bottom plate of the holding plate and the outer surface of the hydrogen flow tube. As it passes through and moves upward, it becomes very easy for the gas to escape.

Embodiment FIG. 1 is a longitudinal cross-sectional view showing the entire hydrogen recovery/purification container according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view showing the structure of the MH holding section in detail.

The hydrogen recovery/purification container of this embodiment has a vertically cylindrical outer container 21 with a half-spherical end plate on the top and bottom.
The main components are a similar cylindrical inner container 22 provided concentrically therein, and a hydrogen gas flow pipe 23 with both ends open, provided along the center line inside the inner container 22. . A space 24 between the outer container 21 and the inner container 22 serves as a flow path for the heat exchange fluid, and a heat exchange fluid introduction pipe 25 and a discharge pipe 26 are provided at the lower and upper parts of the outer container 21, respectively. connected to the heat exchange fluid conduit.

Between the inner container 22 and the hydrogen gas distribution pipe 23
It is designated as MH holding space 27. A felt 28 is filled in the upper and lower ends of this space, which are surrounded by the mirror plates of the missing spherical surface. The cylindrical portion has an annular rising portion 3 having an outer surface that fits loosely into the inner surface of the cylindrical portion.
1 and a bottom plate 32 with a circular hole into which the hydrogen gas flow pipe 23 is loosely fitted. They are sandwich-shaped and filled in multiple layers, stacked one on top of the other. A hydrogen gas exhaust pipe 41 and an inlet pipe 40 are attached to the center line of both upper and lower ends of the inner container 22, respectively, and after passing through the outer container 21 and exiting to the outside, they are connected to an external hydrogen gas conduit.

A hydrogen vent hole 36 is provided in the pipe wall of the hydrogen gas distribution pipe 23 within the thickness of the lower felt layer 34 in the MH holding tray 30 loaded in the MH holding space 27 . The upper and lower ends of the hydrogen gas flow pipe 23 are open, the upper end is held slightly inside the felt 28, and the lower end passes through the felt 28 and is directly connected to the introduction pipe 40.

The upper and lower ends of the MH holding space and the upper and lower felt layers 34 and 35 in the MH holding tray 30 are made of materials having breathability and cushioning properties, such as MG felt or stainless steel felt.

The operation of the embodiment with the above configuration is as described in the section of operation.

In the above embodiment, the heat exchange fluid flow path is provided outside the inner container, but it may be provided in the MH holding space, penetrating the MH holding dish, and parallel to the hydrogen flow pipe.

Effects As described above, according to the present invention, it becomes easy to recover hydrogen, introduce hydrogen gas into the MH in the purification equipment, and discharge hydrogen gas and gas containing impurities from the MH, thereby reducing the absorption and desorption of MH. Consolidation phenomenon caused by repetition is avoided, and a decrease in the amount of hydrogen storage can be prevented.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing the overall configuration of an embodiment of the present invention, FIG. 2 is a sectional view showing the structure of the metal hydride holding section in detail, and FIGS. 1 is a vertical cross-sectional view showing the configuration of a container for hydrogen recovery and purification using chemical compounds. 21... Outer container, 22... Inner container, 23...
...Hydrogen gas flow pipe, 24...Heat exchange fluid flow path, 2
7...Metal hydride holding space, 28, 34,
35...Felt, 30...Holding plate, 33...Fine powder metal hydride layer, 36...Hydrogen vent, 40
...Hydrogen gas introduction pipe, 41...Hydrogen gas discharge pipe.

Claims (1)

[Claims for Utility Model Registration] It has a heat exchange fluid inlet 25 at the bottom, a heat exchange fluid outlet 26 at the top, and a heat exchange fluid flow path 2 inside.
4, a vertically long cylindrical inner container 22 provided in the outer container 21 and having a hydrogen gas discharge pipe 41 in the upper part and a hydrogen gas inlet pipe 40 in the lower part; The hydrogen gas inlet pipe 40 at the lower part of the container 22 is connected to the end of the inner container, and is led inside the inner container 22 to the vicinity of the opening in the inner container of the hydrogen gas exhaust pipe 41, and has a plurality of hydrogen vent holes 36 in the pipe wall. a plurality of metal hydride holding dishes 30 comprising a hydrogen gas distribution pipe 23 having a hydrogen gas distribution pipe 23; a rising portion 31 that loosely fits into the inner surface of the inner container 22; and a bottom plate 32 having a hole through which the hydrogen gas distribution pipe 23 can pass. The holding tray 30 is stacked up to the vicinity of the upper end of the inner container 22 with the hole in the bottom plate 32 passed through the hydrogen gas distribution pipe 23, and inside the holding tray 30, there are felt layers 35, 34 on the top and bottom. Sandwiched with fine powder metal hydride 33
The hydrogen vent hole 36 provided in the tube wall of the hydrogen gas distribution tube 23 is provided within the thickness range of the lower felt layer 34 in each holding tray 30. A hydrogen recovery and purification container characterized in that the opening at the upper end is opened into the upper felt layer 23 of the uppermost holding tray.