JP2003267711A - Method and apparatus for separating and recovering rare gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for separating and recovering a plurality of rare gases respectively from a mixed gas which contains a plurality of the rare gases with less steps and better efficiency. <P>SOLUTION: The mixed gas which contains a plurality of the rare gases and water are introduced into a vessel 1. The inside pressure of the vessel 1 is adjusted so as to produce a hydrate of xenon with water. A xenon hydrate is produced by direct contact of the rare gases with water and introduced to a decomposition vessel 25 after the xenon hydrate is taken out from the vessel 1 using a taking out means 24. The inside temperature and pressure of the decomposition vessel 25 are adjusted so as to decompose the introduced xenon hydrate. Xenon is separated and recovered after the decomposition and refining. And then krypton and argon are separated and recovered in the order after each hydrate is produced in the vessel 1 in which the pressure is set to be suitable for each and introduced in the decomposition vessel 25. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for separating and recovering a rare gas, which contains a plurality of kinds of rare gases such as xenon, krypton, and argon, and separates and recovers the rare gas from a mixed gas such as air. And equipment.

[0002]

2. Description of the Related Art Xenon is used as a gas for filling a bulb or a strobe, as an X-ray CT inhalation gas, and as an anesthetic in medical applications. Krypton
It is used as a gas for filling a halogen bulb, as a base gas in a chamber of a microwave excited high-density plasma device, or as a gas for excimer laser oscillation. Argon is used as a shield gas for welding, as a gas for enclosing an argon laser, and for treating molten aluminum.

In air and the like, a plurality of kinds of rare gases are mixed, and it is necessary to separate and recover a specific rare gas from such a state. Conventionally, a specific rare gas is generally separated mainly by a distillation method. I was collecting it. However, in the case of the distillation method, there has been a problem that the separation needs to be performed at a considerably low temperature and the apparatus becomes large.

Therefore, conventionally, Japanese Patent Laid-Open No. 2000-10754
The one shown in Japanese Patent Publication No. 9 has been proposed. According to this publication example, a raw material gas containing a rare gas and water are introduced into a hydration tank, and the inside of the hydration tank is used for a gas excluding the rare gas contained in the raw material gas. , The temperature and pressure at which the rare gas and water preferentially generate the inclusion compound are generated, and after the inclusion compound of both is generated, the hydration tank is hydrated below the freezing temperature of water. The water in the tank is cooled and solidified, a solid phase consisting of clathrate compound and ice is formed in the hydrated tank, and after degassing the hydrated tank, the clathrate compound is put in the hydrated tank. In this decomposition state, the gas released from the hydration tank is recovered, and the rare gas is separated and recovered.

[0005]

However, in the case of separating and recovering a plurality of kinds of rare gases contained in the raw material gas in the above-mentioned publication, the degassing is performed during the degassing process in the hydration tank. Collect the gas in another container,
After the separation and recovery of the rare gas described above, the degassed gas must be returned from the container into the hydration tank, and the separation and recovery must be performed through the same procedure as in the case of the rare gas described above, resulting in an increase in the number of processes There was a problem of reduced efficiency.

Further, the water in the hydration tank should be cooled to a freezing temperature of water or below to solidify the water in the hydration tank to form a solid phase composed of an inclusion compound and ice in the hydration tank. However, there was still room for improvement, such as the need for a large-scale cooling device.

The present invention has been made in view of the above circumstances, and the invention according to claim 1 efficiently reduces the number of steps for each of a plurality of rare gases from a mixed gas containing a plurality of rare gases. The invention according to claim 2 is intended to enable better separation and recovery, and the invention according to claim 3 is to improve xenon, krypton, and argon satisfactorily. An object of the present invention is to provide a device capable of separating and recovering each of a plurality of types of rare gases from a mixed gas containing a plurality of types of rare gases in a small number of steps.

[0008]

In order to achieve the above-mentioned object, a method for separating and recovering rare gas according to a first aspect of the present invention comprises a container containing a mixed gas containing plural kinds of rare gases and water. Is introduced into the container, and the pressure in the container is directly contacted in a state where the specific rare gas and water are adjusted to a pressure at which hydrate is generated, to generate a hydrate of a specific rare gas, After taking out the hydrate of the rare gas from the inside of the container, after the taking out, the pressure inside the container is adjusted to a pressure at which another specific rare gas and water generate hydrate, and then directly contacted with another hydrate. It is characterized in that a hydrate of a specific rare gas is generated and the generated hydrate of a specific rare gas is taken out from the container.

(Operation / Effect) According to the configuration of the method for separating and recovering rare gas of the invention according to claim 1, the pressure in the container is adjusted to identify the plurality of kinds of rare gas contained in the mixed gas. Noble gas hydrate is generated, and the generated specific noble gas hydrate is taken out from the container. Then, the pressure in the container is adjusted to a pressure adapted to another specific rare gas, and the hydrate of the specific rare gas is extracted from the container in the same manner as described above. The hydrate of the rare gas extracted earlier may be appropriately decomposed to extract the rare gas while the hydrate of another specific rare gas is being generated.

With this, it is only necessary to generate a hydrate of a specific rare gas in the container and take out the hydrate of the specific rare gas from the container. In addition to eliminating the need for gas degassing, in order to degas other than the specified rare gas,
It is not necessary to cool and solidify the hydrate and water of a specific rare gas, and it is also possible to eliminate the need to return the degassed gas again in order to separate multiple rare gases. The number of steps for gas separation can be significantly reduced, and each of a plurality of rare gases can be efficiently separated and recovered.

In order to achieve the above-mentioned object, the invention according to claim 2 is the hydrate of a specific rare gas taken out from the container in the method for separating and recovering rare gas according to claim 1. Is introduced into the decomposition vessel, the temperature and pressure in the decomposition vessel are adjusted to the temperature and pressure at which the hydrate of the rare gas introduced is decomposed, and the rare gas is decomposed and recovered.

(Operation / Effect) According to the structure of the method for separating and recovering rare gas of the invention according to claim 2, the hydrate of a specific rare gas is introduced into the decomposition vessel, and the temperature and pressure in the decomposition vessel are adjusted. By adjusting, the rare gas can be decomposed and recovered.

With this, since the decomposition of the hydrate of a specific rare gas can be promoted, each of a plurality of rare gases can be separated and recovered more efficiently.

In order to achieve the above-mentioned object, the invention according to claim 3 is the method for separating and recovering rare gas according to claim 1 or 2, wherein the rare gas is xenon, krypton or argon. Under the temperature condition of 1 to 10 ° C., the pressure in the container is adjusted to a pressure of 0.15 to 1.5 MPa to generate xenon hydrate, and the xenon hydrate is taken out, The pressure in the container is adjusted to a pressure in the range of 1.5 to 6.4 MPa to generate krypton hydrate, the krypton hydrate is taken out, and then the pressure in the container is adjusted to 7 to 20 M.
The pressure in Pa is adjusted to generate argon hydrate, and the argon hydrate is taken out.

The temperature for producing the hydrate is 1 to 10
℃. This is because if the temperature is lower than 1 ° C, water may be frozen, while if the temperature exceeds 10 ° C, the formation of hydrate is not started, or even if the formation is started, it becomes extremely slow. Desirably 1 to 7 ° C, more desirably 1 to 5 ° C
Is. This is because the generation rate of the hydrate is higher at lower temperatures, and therefore, in order to secure the generation rate of the hydrate, it is desirable to proceed with the generation of the hydrate at a low temperature not lower than 1 ° C.

In the water / argon system, at 6.degree.
At 5 MPa or higher and 10 ° C., 9.5 MPa or higher is the hydrate existence region, and it is said that hydrate formation starts under this condition, but in reality, it is difficult to start generation unless the pressure is higher and the temperature is lower. Therefore, the production is performed at a pressure of 7 MPa or more that can be normally used in industry, for example, a pressure of 20 MPa or less, that is, 7 to 20 MPa. Desirably 8 to 15 MPa, more desirably 9.5 to 12 M
Generation is performed with Pa. 1 ° C for water / krypton system
Is 1.5 MPa or more, and at 10 ° C., 3.8 MPa or more is a hydrate existence region. However, for the same reason as the hydrate production of argon, it is desirable that the krypton hydrate production be performed at a higher pressure than in the above case.
However, in order to separate krypton by hydration, it is necessary to prevent simultaneous formation of hydrate of argon. Argon hydrate is 1 ℃,
Since the existence region is 6.5 MPa or more, the pressure suitable for producing krypton hydrate is 1.5 MPa or more,
It becomes 6.4 MPa or less, that is, 1.5 to 6.4 MPa. Desirably, the generation is performed at 3.0 to 6.0 MPa, more preferably 4.0 to 5.5 MPa. Further, in the water / xenon system, at 1 ° C., 0.15 MPa or more, 1
At 0 ° C., 0.25 MPa or more is the hydrate existence region, but it is desirable to carry out at a higher pressure for the same reason as above. However, in order to separate xenon by hydration, it is necessary to prevent simultaneous production of krypton hydrate. Since krypton hydrate is present at 1 ° C. and 1.5 MPa or higher, the pressure suitable for producing xenon hydrate is 0.15 MPa.
a or more and less than 1.5 MPa, that is, 0.15 to 1.
It becomes 5 MPa. Desirably, 0.5 to 1.3 MPa,
More desirably, the generation is performed at 0.8 to 1.1 MPa.

(Operation / Effect) According to the structure of the rare gas separation / recovery method of the invention according to claim 3, the temperature in the container is kept within a predetermined range for the rare gas containing xenon, krypton, and argon. It is possible to generate and take out hydrates of xenon, krypton, and argon by adjusting the pressure in a predetermined range stepwise while setting. As a result, the difference in the pressure range in which the hydrates of xenon, krypton, and argon are present can be utilized, and the hydrates of xenon, krypton, and argon can be satisfactorily separated without being simultaneously present.

Further, in order to achieve the above-mentioned object, the rare gas separation and recovery apparatus of the invention according to claim 4 introduces a mixed gas containing a plurality of kinds of rare gases and water so as to be in direct contact with each other. Container, a pressure adjusting means for adjusting the pressure in the container to a pressure at which a plurality of kinds of rare gases generate hydrate, a take-out means for taking out the produced hydrate, and a hydrate taken out by the taking-out means Decomposition container for introducing, the temperature in the decomposition container, decomposition temperature adjusting means for adjusting the temperature to decompose the hydrate of the rare gas introduced, the pressure in the decomposition container, the rare gas introduced And a decomposition pressure adjusting means for adjusting the pressure to decompose the hydrate.

(Operation / Effect) According to the structure of the rare gas separation / collection device of the present invention, the mixed gas containing plural kinds of rare gases and water are introduced, and the inside of the container is adjusted by the pressure adjusting means. The pressure of is adjusted to generate the hydrate of a specific rare gas among the multiple types of rare gas contained in the mixed gas, and the generated hydrate of the specific rare gas is taken out from the container by the take-out means and decomposed. Introduced into the vessel, the decomposition temperature adjusting means and the decomposition pressure adjusting means adjust the temperature and pressure in the decomposition vessel to the temperature and pressure for decomposing the hydrate of the introduced rare gas, and decompose the rare gas. Separate and collect.
After taking out the hydrate of the specific rare gas from the container first, the pressure inside the container is adjusted by the pressure adjusting means.
Adjust to a pressure suitable for another specific rare gas, and in the same manner as described above, take out the hydrate of the other specific rare gas from the container by the extracting means and introduce it into the decomposition container. Is decomposed and separated and collected.

As a result, a mixed gas containing plural kinds of rare gases is introduced into the container to generate hydrate, and the hydrate is introduced into the decomposition container from the container to separate and collect a specific rare gas. Thus, the number of steps for separating a plurality of rare gases can be significantly reduced, and an apparatus capable of efficiently separating and recovering each of a plurality of rare gases can be provided.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall schematic configuration diagram showing a first embodiment of a rare gas separation and recovery method and apparatus according to the present invention. Reference numeral 1 denotes a container for producing a hydrate of a rare gas and water. Further, for example, a gas supply pipe 2 for supplying a mixed gas containing a plurality of kinds of rare gases such as air is connected. A first opening / closing valve 3 is interposed in the gas supply pipe 2.

A water supply tank 7 is connected to the container 1 via a water supply pipe 6 having a first pump 4 and a second on-off valve 5. Further, a watering nozzle 8 is provided on the upper part of the container 1, and the watering nozzle 8 and the intermediate portion of the container 1 are the second
It is connected via a circulation pipe 10 in which a pump 9 of FIG. Further, in the container 1, a stirrer 11 that promotes contact between the rare gas and water is additionally provided.

The water supply tank 7 is provided with a cooling jacket 12. A cooling device 13 such as a cooling tower is connected to the cooling jacket 12 via a cooling water pipe 15 having a third opening / closing valve 14. A water temperature sensor 16 for measuring the temperature of the water inside is provided in the water supply tank 7, and the water temperature sensor 16 and the third opening / closing valve 14 are connected to each other, and the temperature is lower than the temperature required in the container 1 by 0.5 ° C. It is set to temperature. As the water temperature is cooled to the set temperature, the third on-off valve 14 is automatically closed to stop the cooling and the water temperature in the water supply tank 7 is maintained at the set temperature.

A nitrogen cylinder 17 for pressurizing the pressure in the container 1 is connected to the container 1 through a pipe 19 having a fourth opening / closing valve 18 interposed therein. A pressure sensor 20 for measuring the internal pressure is provided in the container 1, and a controller 21 is connected to the pressure sensor 20 and a fourth opening / closing valve 18 is connected to the controller 21. A setter (not shown) for setting a predetermined pressure is connected to the controller 21, and the supply of nitrogen gas is stopped as the pressure in the container 1 rises to the set pressure, and the pressure in the container 1 is set to the set pressure. The pressure adjusting means is configured to automatically pressurize.

With the above structure, a mixed gas containing a rare gas and water are introduced into the container 1, and the pressure in the container 1 is adjusted to a pressure at which a specific rare gas and water generate hydrate. It is possible to generate a hydrate of a specific rare gas by directly contacting with.

The container 1 includes a transportation pipe 22 and a transportation pump 2.
3 is connected to the take-out means 24, and the transportation pipe 2
A decomposition container 25 is connected to the device 2. The decomposition container 25 is provided with a heater 26 as a heating device, and the decomposition container 25 is provided with a temperature sensor 27 for measuring an internal temperature. The temperature sensor 27 and a switch 28 of the heater 26 are provided.
Is connected, and when the temperature reaches room temperature such as 20 ° C., the heater 26 is stopped and the decomposition temperature adjusting means is configured to maintain the temperature inside the decomposition container 25 at room temperature.

Further, a vacuum pump (not shown) is connected to the decomposition container 25, and a fifth on-off valve 29 having a check function for preventing the invasion of the atmosphere to the decomposition container 25 side is interposed. A pipe 30 is connected so that the pressure in the decomposition container 25 can be reduced to below atmospheric pressure and the air in the decomposition container 25 can be degassed. This decompression configuration is referred to as decomposition pressure adjusting means.

Further, the decomposition vessel 25 includes a rare gas recovery pipe 3
1 is connected to the rare gas recovery pipe 31, and a xenon recovery cylinder 32, a krypton recovery cylinder 33, and an argon recovery cylinder 34 are connected via a branch recovery pipe 36 having an on-off valve 35 interposed therebetween. ing. On-off valve 3
Each of the 5 has a non-return function for preventing the flow toward the decomposition container 25 side.

With the above structure, xenon, krypton and argon can be separated and recovered in that order from a mixed gas containing a rare gas such as air, which will be described in detail below.

(1) The first pump 4 is driven, the second opening / closing valve 5 is opened, and a predetermined amount of water is introduced into the container 1 through the water supply pipe 6. The temperature of this water is less than the temperature required in the container 1 in consideration of the amount of heat released in the container 1 and the like.
The temperature is set to be lower by 5 ° C., and with the introduction thereof, the temperature in the container 1 becomes suitable for producing hydrate. (2) Open the first on-off valve 3, and through the gas supply pipe 2,
A mixed gas containing a rare gas is introduced into the container 1. The mixed gas may be either air or a gas in which the concentration of the rare gas is increased in advance. (3) In the controller 21, a pressure (1.0
(MPa), the fourth on-off valve 18 is opened after closing the first on-off valve 3, and nitrogen gas is introduced into the container 1 from the nitrogen cylinder 17 until the set pressure is reached. (4) The stirrer 11 is driven to bring the rare gas and water into direct contact with each other to generate xenon hydrate. (5) After the generation of xenon hydrate, the stirrer 11 is stopped, the fifth opening / closing valve 29 is opened to degas and decompress the inside of the decomposition container 25, and then the transport pump 23 is driven to transport the transport pipe 22. Xenon hydrate is transported to the inside of the decomposition container 25 through. At the time of this transportation, the amount of water commensurate with the amount of drainage from the container 1 is replenished from the water supply tank 7, and the xenon hydrate floating on the liquid surface is satisfactorily transported into the decomposition container 25 and the upper space in the container 1 The gas is prevented from being discharged inside the decomposition container 25. (6) After the transportation is completed, the on-off valve 35 for the xenon recovery cylinder 32 is opened, the switch 28 is closed, the heater 26 is started, and the temperature is automatically raised to room temperature, such as 20 ° C., and the xenon hydrate is removed. After decomposition and purification, xenon is taken out and collected in the xenon recovery cylinder 32. In this decomposed state, water is allowed to maintain a liquid phase.

(7) After the above-mentioned transportation is completed or after the xenon is recovered, the amount of water in the container 1 is returned to the state before the generation of hydrate of xenon, and then only krypton is hydrated in the controller 21. Set the pressure (5.0 MPa) that will not freeze water,
The fourth opening / closing valve 18 is opened, and nitrogen gas is introduced into the container 1 from the nitrogen cylinder 17 until the set pressure is reached. (8) Thereafter, the stirrer 11 is driven and the second pump 9 is activated to sprinkle water from the water sprinkling nozzle 8 so that the noble gas remaining in the container 1 is brought into direct contact with water, so that the krypton hide Generate rates. (9) Then, in the same manner as (5) and (6) described above,
Cryptone recovery cylinder 33 by decomposing and purifying krypton
To collect.

(10) After the transportation of krypton hydrate or after the recovery of krypton, the amount of water in the container 1 is returned to the state before the production of krypton hydrate, and then only argon is hydrated in the controller 21. Pressure (10MP)
a), the fourth on-off valve 18 is opened, and nitrogen gas is supplied from the nitrogen cylinder 17 to the container 1 until the set pressure is reached.
Introduce inside. (11) After that, the agitator 11 is driven and the second
The pump 9 of the above is activated to sprinkle water from the sprinkling nozzle 8, and the container 1
The noble gas remaining inside is brought into direct contact with water to produce hydrate of argon. (12) Thereafter, in the same manner as in (5) and (6) described above, the argon is decomposed and purified to obtain the argon recovery cylinder 34.
To collect. As described above, xenon, krypton, and argon can be decomposed and purified in that order to be collected.

FIG. 2 is a partially omitted overall configuration diagram showing the second embodiment, and is different from the first embodiment in the following points.

That is, in the stirrer 41 provided in the container 1, three stirring blades 4 are vertically spaced at a predetermined interval.
Two are provided. The container 1 is individually provided with a xenon transport pipe 43, a krypton transport pipe 44, and an argon transport pipe 45 in a state of being adjusted to the height of each of the three stirring blades 42. An on-off valve 46 is provided in the.

Each of the transportation pipes 43, 44, 45 is connected on the downstream side to a merging transportation pipe 48 provided with a transportation pump 47. The xenon transportation pipe 43, the krypton transportation pipe 44, the argon transportation pipe 45, the opening / closing valve 46, the transportation pump 47 and the confluent transportation pipe 48 are referred to as a take-out means 49. Other configurations are first
Since this is the same as the embodiment, the same drawing number is assigned and the description thereof is omitted.

According to the second embodiment, after the xenon hydrate is produced and taken out, the water is replenished from the water supply tank 7 to a position higher than that at the time of producing the xenon hydrate to produce the krypton hydrate. And then
Further, water is replenished from the water supply tank 7 to a position higher than that to generate argon hydrate, and accordingly, the pressure in the container 1 can be increased and the nitrogen cylinder 1
Since the amount of pressure increase due to nitrogen gas from 7 is small, there is an advantage that nitrogen consumption can be reduced.

FIG. 3 is a partially omitted overall configuration diagram showing a third embodiment. The difference from the second embodiment is as follows.

That is, the container 1 has three stirring blades 42.
Open / close valve 51 with each height adjusted
And a xenon transportation pipe 53 provided with a transportation pump 52,
A krypton transportation pipe 54 and an argon transportation pipe 55 are provided, and a take-out means 56 is configured.

A xenon decomposition vessel 57 and a krypton decomposition vessel 5 are individually provided in each of the xenon transportation pipeline 53, the krypton transportation pipeline 54, and the argon transportation pipeline 55.
8. The decomposition container 59 for argon is connected.

Each of the decomposition vessels 57, 58, 59 is provided with a structure for reducing the pressure and a structure for increasing the temperature, as in the above-described embodiment. The other structure is the same as that of the second embodiment, and the same drawing numbers are given and the description thereof is omitted.

According to the third embodiment, the pipes 53, 5 dedicated to the transportation and decomposition and purification of xenon hydrate, krypton hydrate and argon hydrate, respectively.
4, 55 and the decomposition vessels 57, 58, 59, it is easy to avoid mixing rare gases with each other, and it is possible to easily collect a rare gas with high pure accuracy.

In the above embodiment, xenon hydrate,
Considering that the temperatures for producing krypton hydrate and argon hydrate can be the same,
A cooling jacket 12 is provided on the water supply tank 7,
A cooling device 13 is connected to the cooling jacket 12 so that the water temperature in the water supply tank 7 is maintained at a set temperature, and the container 1
Although the internal temperature can be adjusted to the set temperature, various configurations are adopted as the present invention, for example, by providing the container 1 with a cooling jacket so that the cooling temperature can be adjusted appropriately. it can.

[0043]

As is apparent from the above description, according to the rare gas separation and recovery method of the present invention, a hydrate of a specific rare gas is generated in a container, and the hydrate of the specific rare gas is generated. Since it is only necessary to take out the gas from the container, it is possible to eliminate the need for degassing of gases other than the specified rare gas as in the past, and to remove the gas other than the specified rare gas, It is not necessary to cool and solidify the hydrate and water of, and it is also possible to return the degassed gas again to separate multiple kinds of rare gases,
The number of steps for separating a plurality of rare gases can be significantly reduced, and each of a plurality of rare gases can be efficiently separated and recovered.

[Brief description of drawings]

FIG. 1 is an overall schematic configuration diagram showing a first embodiment of a rare gas separation and recovery apparatus according to the present invention.

FIG. 2 is a partially omitted overall schematic configuration diagram showing a second embodiment.

FIG. 3 is a partially omitted schematic configuration diagram showing a third embodiment.

[Explanation of symbols]

1 ... Container 17 ... Nitrogen cylinder (pressure adjusting means) 18 ... Fourth on-off valve (pressure adjusting means) 19 ... Piping (pressure adjusting means) 20 ... Pressure sensor (pressure adjusting means) 21 ... Controller (pressure adjusting means) 24 ... Taking out means 25 ... Disassembly container 26 ... Heater (decomposition temperature adjusting means) 27 ... Temperature sensor (decomposition temperature adjusting means) 28 ... Switch (decomposition temperature adjusting means) 29 ... Fifth on-off valve (disassembly pressure adjusting means) 30 ... Intake pipe (disassembly pressure adjusting means) 49 ... Taking out means 56 ... Taking out means

Continued front page    F-term (reference) 4G075 AA03 AA61 BA10 BB05 BD13                       BD17 CA03 CA05 CA65 DA01                       DA13 DA18

Claims (4)

[Claims] 1. A state in which a mixed gas containing a plurality of rare gases and water are introduced into a container, and the pressure in the container is adjusted to a pressure at which a specific rare gas and water generate hydrate. To produce a hydrate of a specific rare gas by direct contact with, the hydrate of the generated specific rare gas is taken out of the container, and after taking out, the pressure in the container is changed to another specific rare gas. Directly contacting with water to adjust the pressure to generate hydrate to generate another specific noble gas hydrate, and removing the generated another specific noble gas hydrate from the container. Characteristic method for separating and recovering rare gas. 2. The method for separating and recovering rare gas according to claim 1, wherein the hydrate of the specific rare gas taken out from the container is introduced into the decomposition container, and the temperature and pressure in the decomposition container are introduced. A method for separating and recovering a rare gas, in which the temperature and pressure for decomposing the hydrate of the generated rare gas are adjusted, and the rare gas is decomposed and recovered. 3. The method for separating and recovering a rare gas according to claim 1 or 2, wherein the rare gas contains xenon, krypton, and argon, and the pressure in the container is 1 to 10 ° C. Is adjusted to a pressure of 0.15 to 1.5 MPa to generate xenon hydrate, the xenon hydrate is taken out, and then the pressure in the container is adjusted to a pressure of 1.5 to 6.4 MPa. To produce krypton hydrate, take out the krypton hydrate, and then adjust the pressure in the container to a pressure within 7 to 20 MPa to produce argon hydrate and take out the argon hydrate. Noble gas separation and recovery method. 4. A container into which a mixed gas containing plural kinds of rare gases and water are introduced so as to be in direct contact with each other, and a pressure in the container is adjusted to a pressure at which each of the plural kinds of rare gases produces hydrate. The pressure adjusting means, the taking-out means for taking out the produced hydrate, the decomposition vessel for introducing the hydrate taken out by the taking-out means, the temperature in the decomposition vessel, and the temperature of the decomposition vessel for decomposing the introduced noble gas hydrate. Decomposition temperature adjusting means for adjusting the temperature, decomposition pressure adjusting means for adjusting the pressure in the decomposition vessel to a pressure for decomposing the hydrate of the introduced rare gas; Separation and collection device.