JP3385410B2 - Noble gas purification method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for purifying rare gases, especially krypton and xenon, and more specifically,
The present invention relates to a method and a device for purifying krypton and xenon which are concentrated in liquefied oxygen in the upper part of a double rectification column and the lower part of an air liquefaction separation device.

[0002]

2. Description of the Related Art Conventionally, krypton and xenon which are concentrated in liquefied oxygen of an air liquefaction separation apparatus are taken out and purified, and the purified krypton and xenon are separated into each. Usually, these devices use krypton 90 by an operation mainly for rectifying the liquefied oxygen.
After obtaining a concentrated solution of .about.95% and xenon of 5 to 7%, krypton and xenon are further separated.

[0003]

However, since the amounts of krypton and xenon contained in the atmosphere are extremely small, continuous purification cannot be performed, and it is difficult to manufacture a device having a consistent purification process. It was In addition, liquefied oxygen, which is a raw material, contains various components that are present in the air in extremely small amounts. Among them, halogen-based impurities such as sulfur hexafluoride, Freon 13, Freon 14, Freon 16
Etc. cannot be removed by a rectification operation, a catalytic reaction, an adsorption separation operation, etc., which are usually provided in a rare gas purification step,
It will be mixed in the krypton and xenon of the product in a more concentrated state.

Therefore, finally, a rectification operation for separating the product krypton and the product xenon is performed, and after collecting the product krypton and the product xenon, a rectification operation for separating the krypton, xenon and the halogen impurities is performed again. The halogen-based impurities are separated and removed. However, if the separation and removal are performed by rectification, there is a problem that the product yields of the product krypton and xenon decrease.

Further, since the rectification operation must be repeated from the viewpoint of operation, not only the operation time becomes long, but also an extremely advanced operation technique is required, which becomes a factor that hinders the automation of operation, for example. Was there.

In particular, the above-mentioned halogen-based impurities are extremely stable substances, and it has been conventionally difficult to remove them by decomposition and reaction, but in recent years, they have been removed by reaction by using getter agents. It was announced that is possible. For example, in Japanese Examined Patent Publication No. 4-149010, calcium or magnesium is used as a getter agent, and if necessary, a titanium or zirconium-based getter agent is used in combination at an appropriate temperature, for example, 500 to 7.
It is described that halogen-based impurities can be removed by heating to 00 ° C. and treating.

However, since the treatment with the getter agent is carried out by passing gas through the reaction tube filled with the getter agent, a pressure loss of 1.5 to 2.0 kg / cm ² G is usually generated. Therefore, when a treatment facility using a getter agent is simply added to the conventional rare gas refining facility, it is necessary to install a booster corresponding to the pressure loss at the same time, resulting in an increase in facility cost, power cost and the like.

[0008] Usually, krypton or xenon is collected by solidifying and sucking a collector immersed in liquefied nitrogen from the final separation rectification column, and then heating the collector to raise the pressure, The method of filling the product cylinder was used. In this case, the product cylinder pressure depends on the capacities of the collector, the product cylinder and its communicating pipe. The larger the volume of the product cylinder is than the combined volume of the collector and the communicating pipe, the pressure inside the product cylinder. Can be higher.

Therefore, if the reaction tube using the above-mentioned getter agent is installed between the collector and the product cylinder (filling table), the volume of the communication pipe portion is increased and it is difficult to increase the product pressure. become. Furthermore, since it is necessary to install a reaction cylinder in each of krypton and xenon, and the design pressure of the reaction cylinder also becomes high, there is a problem in terms of equipment cost.

Therefore, the present invention provides a refining method and apparatus capable of efficiently separating the above-mentioned rare gases such as krypton and xenon, and further obtaining highly purified rare gases such as krypton and xenon. Is intended.

[0011]

In order to achieve the above-mentioned object, the method for purifying a rare gas according to the present invention is a method for purifying most of liquefied oxygen containing a rare gas such as krypton or xenon derived from an air liquefaction separation device. A crude purification system for removing oxygen and hydrocarbons of the above to obtain a rare gas concentrated in a liquid state, and a high purification system for removing impurities such as hydrocarbons and oxygen remaining in the liquid rare gas concentrated in the crude purification system. In a method of purifying a rare gas by a pure purification system, the liquid rare gas obtained in the crude purification system is temporarily stored in a self-pressurized storage tank, and pressurized in the storage tank to be introduced into the high-purity purification system, It is characterized in that the halogen-based impurities in the rare gas are removed in the halogen-based impurity removal step using a getter provided in the high-purity purification system. In addition, in the present invention
"Self-pressurized storage tank" is a storage tank that stores liquefied gas
And an evaporator and an evaporator for evaporating the liquefied gas discharged from the storage tank.
And a pressure valve for introducing the gas evaporated in the evaporator into the storage tank.
It is equipped with a passage that has a
The liquefied gas derived from the
It is heated and evaporated, and the evaporated gas is introduced into the storage tank.
Then, the inside of the storage tank is raised to a predetermined pressure, and this pressure
Supplying the liquefied gas in the storage tank to the desired equipment and facilities
Is .

Further, the method of the present invention removes most of oxygen and hydrocarbons in liquefied oxygen containing krypton and xenon discharged from the air liquefaction separation device to obtain a liquid mixture of krypton and xenon. A crude purification system and hydrocarbons remaining in the liquid mixture concentrated in the crude purification system,
In a method for purifying a rare gas by removing impurities such as oxygen and then by a highly pure purification system for rectifying and separating krypton and xenon, the liquid mixture obtained in the crude purification system is temporarily stored in a self-pressurized storage tank. While being pressurized in the storage tank and introduced into the highly pure purification system, the halogen-based impurities contained in the liquid mixture are removed by a getter before the rectifying and separating the krypton and xenon, and further, In a method for purifying and separating krypton and xenon from liquefied oxygen containing krypton and xenon derived from an air liquefaction separation device, a step of introducing the liquefied oxygen into a concentrating column to concentrate krypton and xenon in a bottom liquid, A methane purging step of introducing the bottom liquid of the concentration tower into the methane purging tower and purging methane from the tower top with oxygen gas, and the methane purging step. A first catalytic reaction step of vaporizing the column bottom liquid and introducing it into the first catalytic reaction tube to react the contained hydrocarbons with oxygen, and the gas after the first catalytic reaction tube is led to the first adsorber. A first adsorption step of introducing and adsorbing and removing water and carbon dioxide produced in the first catalytic reaction step, a gas after the derivation of the first adsorption step were provided with a condenser at the top of the column and a vaporizer at the bottom of the column. Deoxygenation step of introducing into the deoxygenation tower for rectification, derivation and removal of oxygen gas from the top of the tower, and the bottom liquid of the deoxygenation tower is temporarily stored in a self-pressurized storage tank, and pressurized in the storage tank to be discharged And a second catalytic reaction step in which the pressurized column bottom liquid is vaporized and introduced into the second catalytic reaction column to react the contained hydrocarbons with oxygen, and the second catalytic reaction. A second adsorption step of introducing the gas after being discharged from the cylinder into a second adsorber to adsorb and remove water and carbon dioxide produced in the second catalytic reaction step A third catalytic reaction step in which hydrogen is added to the gas after the second adsorption step is introduced and introduced into a third catalytic reaction column, and oxygen contained therein is reacted with the hydrogen to produce water, and the third catalytic reaction A drying step of introducing the gas after the tube is introduced into a drier to remove water generated in the third catalytic reaction step, and a gas after the drying step is cooled and liquefied to separate the excessively added hydrogen. Gas-liquid separation process,
Halogen-based impurity removal step of vaporizing the liquid derived from the gas-liquid separation step to remove halogen-based impurities by a getter, and gas after the halogen-based impurity removal step is vaporized at the top of the condenser and at the bottom of the tower. It is characterized in that it is introduced into a separation column equipped with a vessel for rectification, and xenon is extracted from the bottom of the column and krypton is extracted from the top of the column.

Further, as an apparatus configuration for carrying out the method of the present invention, most oxygen and hydrocarbons in liquefied oxygen containing noble gases such as krypton and xenon derived from an air liquefaction separation apparatus are removed. And a highly pure purification system for removing impurities such as hydrocarbons and oxygen remaining in the liquid rare gas concentrated by the crude purification system. In the gas purification apparatus, between the crude purification system and the high-purity purification system, the liquid rare gas obtained in the rough purification system is temporarily stored, and is pressurized to be introduced into the high-purity purification system. A storage tank is installed, the high-purity purification system is equipped with a halogen-based impurity removing device using a getter that removes halogen-based impurities in the rare gas,
A crude purification system for obtaining a liquid mixture of krypton and xenon by removing most of oxygen and hydrocarbons in liquefied oxygen containing krypton and xenon derived from an air liquefaction separator, and the crude purification system. In a rare gas purification apparatus equipped with a high-purity purification system for removing hydrocarbons, impurities such as oxygen remaining in the concentrated liquid mixture, and for rectifying and separating krypton and xenon, a rare gas purification apparatus, Between the pure purification system, the liquid rare gas obtained in the crude purification system is temporarily stored, and a self-pressurized storage tank for introducing the pressurized rare gas into the highly pure purification system is installed, and the krypton and xenon are provided. A halogen-based impurity removal device using a getter that removes halogen-based impurities was installed in front of the rectification column for rectification separation, and more specifically, krypton derived from an air liquefaction separation device. In a device for purifying and separating krypton and xenon from liquefied oxygen containing bismuth and xenon, a concentration column for concentrating the krypton and xenon in the liquefied oxygen into a liquid at the column bottom, and methane contained in the bottom liquid of the concentration column A methane purge tower for purging from the top of the tower with oxygen gas, and a vaporization means for vaporizing the bottom liquid of the methane purge tower,
A first catalytic reaction tube for reacting hydrocarbons and oxygen in the gas vaporized in the vaporizer with oxygen, and a first adsorber for adsorbing and removing water and carbon dioxide produced by the reaction in the first catalytic reaction tube Cooling means for cooling the gas after the first adsorber is discharged,
A deoxygenation tower that is equipped with a condenser at the top of the tower and an evaporator at the bottom of the tower, rectifies the gas cooled by the cooling means, and removes and removes oxygen gas in the gas from the top of the tower; A self-pressurizing storage tank for temporarily storing the bottom liquid, a vaporization means for vaporizing the liquid pressurized by the self-pressurizing storage tank, and a hydrocarbon for reacting oxygen with hydrocarbons contained in the vaporized gas. A two-catalyst reaction tube, a second adsorber for adsorbing and removing water and carbon dioxide produced by the reaction in the second catalytic reaction tube, and a hydrogen adding means for adding hydrogen to the gas after the second adsorption step is derived, A third catalytic reaction tube for reacting the hydrogen added by the hydrogen adding means with oxygen contained in the gas, a drying means for removing water generated by the reaction in the third catalytic reaction tube, and a post-drying Gas-liquid separation means for cooling and liquefying the gas of the above to separate unliquefied hydrogen, and the gas-liquid separation means Vaporizing means for vaporizing the liquid derived from the above, halogen-type impurity removing means using a getter for removing halogen-based impurities in the vaporized gas, and liquefying means for cooling and liquefying the gas derived from the halogen-based impurity removing means And a separation and rectification column for rectifying the liquefied gas liquefied by the liquefying means to derive xenon from the bottom of the column and krypton from the top of the column.

[0014]

[Operation] According to the above configuration, the rare gas such as krypton and xenon in the liquefied oxygen derived from the air liquefaction separation device can be efficiently purified to high purity in a consistent process.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail based on an embodiment shown in FIG. First, from the main condenser evaporator 1a portion of the upper column lower part of the double rectification column 1 of the air liquefaction separation device,
Liquefied oxygen in which krypton (100 to 1000 ppm) and xenon (10 to 100 ppm) are concentrated is discharged and introduced into the concentration tower 2. A vaporizer (reboiler) 3 using nitrogen gas or the like as a heating source is provided at the bottom of the concentrating tower 2, and heats the tower bottom liquid to generate rising gas. As a result, the liquefied oxygen containing krypton and xenon introduced from the double rectification column 1 is rectified by the concentration column 2 to obtain a concentrated liquid in which krypton and xenon are concentrated 10 to 20 times at the bottom of the column. , Oxygen gas pipe 4 from the top of the tower
Be derived to.

In the concentrated liquid at the bottom of the column, in addition to krypton and xenon, methane contained in the liquefied oxygen as a raw material may be concentrated to about 1000 ppm. Since it is not preferable for safety that the methane concentration is further increased, a methane purge tower 5 is provided as necessary, and methane is purged in the methane purge tower 5. The concentrated liquid at the bottom of the concentration tower 2 is led out to a pipe 6 and introduced as a reflux liquid to a methane purge tower 5 installed at a position where the liquid head of the concentrated liquid can naturally flow. A reboiler 7 is provided at the bottom of the methane purge tower 5 and heats the tower bottom liquid to generate rising gas. Oxygen gas containing a large amount of methane is extracted from the top of the methane purge tower 5 into a pipe 8, and about 90 krypton is present at the bottom of the methane purge tower 5.
00 ppm and xenon are concentrated to about 1000 ppm, and hydrocarbons (including residual methane) contained in the raw material liquefied oxygen are concentrated to about 1000 ppm.

Since excessive concentration of hydrocarbons in the liquefied oxygen is dangerous, a step of removing the hydrocarbons is performed next. In this hydrocarbon removal step, first, the tower bottom liquid derived from the bottom of the methane purge tower 5 is vaporized by the heat exchanger 9, then heated to room temperature by the heater 10, and further preheater 1
In step 1, the mixture is heated to about 300 ° C. and introduced into the first catalytic reaction column 12, and the hydrocarbons contained therein are reacted with oxygen to form carbon dioxide and water. The gas discharged from the first catalytic reaction tube 12 is cooled in the cooler 13 and then introduced into one of the first adsorbers 14 which are used by switching, and the carbon dioxide and water generated by the catalytic reaction are adsorbed and removed.

The gas derived from the first hydrocarbon removal step is cooled by the heat exchanger 15 and is condensed at the top of the condenser 1.
6. Introduced into the middle stage of the deoxygenation tower 18 having a reboiler 17 at the bottom of the tower. As a result of the rectification in the deoxygenation tower 18, 10 to 5 krypton is stored in the condenser 16 at the top of the tower.
Oxygen gas containing 0 ppm was separated and led out from the pipe 19 and removed, and a liquefied gas (crude separation liquefaction) composed of 90 to 95% of krypton and 5 to 10% of xenon at the bottom of the column and the balance of oxygen and a small amount of hydrocarbons. Gas) separates.

Up to this point, the crude refining system A is normally operated continuously, and the liquefied gas at the bottom of the deoxygenation tower 18 is
A self-pressurized storage tank 22 led out into a pipe 21 equipped with a valve 20.
It is stored inside. The self-pressurizing storage tank 22 is
Part of the liquid gas stored in
The evaporator 25 for causing the gas evaporated in the evaporator 25 to
The path provided with the pressurizing valve 24 introduced into the storage tank 22 is
It is attached to the storage tank 22. The liquefied gas in the self-pressurized storage tank 22 is led out to the pipe 23 when the liquefied gas reaches a predetermined amount, that is, an amount capable of rectifying and separating in a later step, and is separated from the remaining oxygen and hydrocarbons. It is sent to a highly pure purification system B which separates krypton and xenon. At this time,
The valve 20 of the pipe 21 connected to the deoxygenation tower 18 is closed, the pressurizing valve 24 is opened, and the gas evaporated in the evaporator 25 is introduced into the storage tank 22, whereby the storage tank 2
It is possible to raise the pressure inside 2 to the predetermined pressure, for example, the liquid discharged to the pipe 23 to an arbitrary pressure up to 8 kg / cm 2 G, for example.

The liquefied gas discharged to the pipe 23 is first vaporized in the heating evaporator 26 and then further heated in the preheater 27 to about 3%.
After being heated to 00 ° C. and introduced into the second catalytic reaction cylinder 28,
A slight amount of residual hydrocarbon is reacted with oxygen so that the residual amount of hydrocarbon is reduced to the product content allowable value or less. Next, after being cooled by the cooler 29, it is introduced into the second adsorber 30,
Carbon dioxide and water produced by the catalytic reaction are removed.

Further, in the gas discharged from the second adsorber 30,
An appropriate amount of hydrogen is added from the pipe 31 and introduced into the third catalytic reaction tube 32, and the remaining oxygen is reacted with the added hydrogen to form water. At this time, the recovered gas in the balloon 33 is introduced into the gas discharged from the second adsorber 30 via the recovery pump 34 and the pipe 35, and the yield is improved.

The gas discharged from the third catalytic reaction tube 32 is cooled by a cooler 36 and a refrigerating dryer 37, and then introduced into a third adsorber 38, where the produced water is adsorbed and removed to produce krypton and krypton. It becomes a gas containing xenon as a main component, and halogen-based impurities that could not be separated in the steps up to this point, and the balance of hydrogen excessively added from the tube 31.

The gas thus enriched with krypton and xenon is cooled in the heat exchanger 39, and then introduced into the liquefier 40 to be liquefied and separated in the separation column 41 for rectifying and separating krypton and xenon. Introduced in the middle stage. A condenser 42 is provided on the top of the liquefier 40, and hydrogen that is not liquefied in the condenser 42 is recovered from the pipe 43 to the balloon 33.

The separation tower 41 is provided with a reboiler 44 at the bottom and a condenser 45 at the top, and is composed of krypton and xenon which are liquefied by the liquefier 40 and introduced into the separation tower 41. The mixed liquefied gas is
Fractionation in the column separates krypton having a purity of 99.995% or more at the top and 99.995% of purity at the bottom.
The above xenon is separated in liquid form. The low-boiling point component that is not condensed in the condenser 45 is recovered from the pipe 46 in the balloon 33, and the krypton and xenon separated in the separation column 41 are led out to the pipe 47 and the pipe 48, respectively, and collected in the same manner as in the conventional case. Product cylinders 51, 52 through containers 49, 50
To be filled.

Here, by installing the self-pressurizing storage tank 22 between the crude purification system A and the highly purified system B as described above, the pressure in the highly purified system B can be increased. From a factory that only installs a crude refining system A that operates continuously, to a highly pure refining system B that is installed in another factory
Even when the crude separated liquefied gas is transported, it is not necessary to install a booster, and the equipment cost and operating cost can be reduced.

The high-purity refining system B is operated in a batch operation, and is started when the liquefied gas in the self-pressurizing storage tank 22 is accumulated, and is stopped until a predetermined amount is accumulated. Regeneration of the second adsorber 30 and the third adsorber 38 is performed.

FIG. 2 shows a step of removing halogen-based impurities contained in the liquefied gas liquefied by the liquefier 40 and introduced into the separation column 41. The liquefied gas that has been liquefied in the liquefier 40 and in which most of the hydrogen not condensed in the condenser 42 has been separated and removed is led out from the bottom of the liquefier 40 and vaporized in the warmer 53, and then 500-700 in the heater 54. It is introduced into the reaction tube 55 which is heated to ° C. The reaction tube 55 is filled with a gettering agent such as a calcium, magnesium, titanium, and zirconium-based material, and the chlorofluorocarbon 1 is contained in the gas at several tens of ppm.
Halogen-based impurities such as 3, Freon 14, Freon 16, C _n F _m , and sulfur hexafluoride are removed by reaction to about 0.5 ppm or less.

The mixed gas of krypton and xenon from which halogen-based impurities have been removed is cooled to room temperature by the cooler 56, further cooled and liquefied by the heat exchanger 57, and introduced into the separation column 41.

The halogen-based impurity removing step using the getter can be installed at any of the above-mentioned purification step and filling step, but as described above, the liquefier 40 and the separation column are used. By arranging the halogen-based impurity removing step between the first and the second gas generators 41, the processing gas contains almost no oxygen or hydrogen that reacts with the getter agent, so that the halogen-based impurities can be removed extremely efficiently by reaction. . Moreover, since the pressure loss in the reaction tube 55 can be covered by the self-pressurizing storage tank 22, it can be carried out at low cost without the need for a booster.

Further, the constitution of each part of the above-mentioned purification step in the present invention is not limited to the above-mentioned embodiment, and can be carried out with an optimal constitution according to the amount of product collected and the like.

[0031]

As described above, according to the present invention,
Since the liquefied gas from the crude purification system can be sent to the high-purity purification system at an appropriate pressure without using a booster, even if both systems are installed at distant places, the gas can be sent at low cost. In particular, even if a process involving pressure loss, that is, a halogen-based impurity removing process using a getter that removes halogen-based impurities is provided in the system, it is possible to operate at low cost, and it is possible to operate at high cost without halogen-based impurities. A rare gas of high purity can be obtained in a series of steps, and automatic operation is possible.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is a system diagram of a halogen-based impurity removal process.

[Explanation of symbols]

1 ... Double rectification tower, 2 ... Concentration tower, 5 ... Methane purge tower, 12
... first catalytic reaction column, 14 ... first adsorber, 18 ... deoxidation tower, 22 ... self-pressurized storage tank, 28 ... second catalytic reaction column, 3
0 ... 2nd adsorption device, 32 ... 3rd catalytic reaction column, 38 ... 3rd adsorption device, 40 ... Liquefier, 41 ... Separation column, 55 ... Reaction column, A
… Coarse purification system, B… High purity purification system

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F25J 3/00-3/08

Claims (8)

(57) [Claims] 1. A crude purification system for obtaining a rare gas concentrated to a liquid by removing most of oxygen and hydrocarbons in liquefied oxygen containing a rare gas such as krypton and xenon derived from an air liquefaction separator. In the method for purifying a rare gas by a highly pure purification system that removes impurities such as hydrocarbons and oxygen remaining in the liquid rare gas concentrated in the crude purification system, A method for purifying a rare gas, wherein the rare gas is temporarily stored in a self-pressurized storage tank, pressurized in the storage tank, and introduced into the highly pure purification system. 2. The method for purifying a rare gas according to claim 1, wherein the high-purity purification system includes a halogen-based impurity removing step using a getter that removes a halogen-based impurity in the rare gas. . 3. A crude purification system for obtaining a liquid mixture of krypton and xenon by removing most of oxygen and hydrocarbons in liquefied oxygen containing krypton and xenon derived from an air liquefaction separator. In the method for purifying a rare gas by removing impurities such as hydrocarbons and oxygen remaining in the liquid mixture concentrated by the crude purification system, and then by a high-purity purification system for rectifying and separating krypton and xenon, The liquid mixture obtained in the crude purification system is temporarily stored in a self-pressurization type storage tank, and while being pressurized in the storage tank to be introduced into the high-purity purification system, the krypton and xenon are rectified and separated, and the liquid mixture is formed. A method for purifying a rare gas, which comprises removing halogen-containing impurities contained by a getter. 4. A method for purifying and separating krypton and xenon from liquefied oxygen containing krypton and xenon, which is derived from an air liquefaction separation device, wherein the liquefied oxygen is introduced into a concentration column to concentrate krypton and xenon in a bottom liquid. And a methane purging step of introducing the concentration tower bottom liquid into a methane purging tower and purging methane from the tower top with oxygen gas, and vaporizing the methane purging tower bottom liquid and introducing it into the first catalytic reaction column. A first catalytic reaction step of reacting contained hydrocarbons with oxygen, and water and carbon dioxide produced in the first catalytic reaction step by introducing the gas after the first catalytic reaction tube is introduced into a first adsorber A first adsorption step of adsorbing and removing, and introducing the gas after derivation of the first adsorption step into a deoxygenation tower for rectification,
A deoxygenation step of discharging and removing oxygen gas from the top of the tower, a pressure step of temporarily storing the bottom liquid of the deoxygenation tower in a self-pressurized storage tank, and pressurizing and discharging in the storage tank, and the pressurized A second catalytic reaction step in which the column bottom liquid is vaporized and introduced into the second catalytic reaction column to react the contained hydrocarbons with oxygen, and the gas after the second catalytic reaction column is led to the second adsorber. The second adsorption step of introducing and adsorbing and removing water and carbon dioxide produced in the second catalytic reaction step, and adding hydrogen to the gas after derivation of the second adsorption step and introducing it into the third catalytic reaction tube to contain it. A third catalytic reaction step of reacting oxygen with the hydrogen to form water, and a drying step of introducing the gas after the third catalytic reaction tube is introduced into a dryer to remove water generated in the third catalytic reaction step. And a gas-liquid separation step of cooling and liquefying the gas after the drying step and separating the excessively added hydrogen. A halogen-based impurity removing step of removing the halogen-based impurities by a getter by vaporizing the liquid derived from the gas-liquid separation step, and introducing the gas after the halogen-based impurity removal step into the separation column to remove xenon from the bottom of the tower. And a separation step of deriving krypton from the top of the column, which is carried out in sequence. 5. A crude purification system for obtaining a rare gas concentrated to a liquid by removing most of oxygen and hydrocarbons in liquefied oxygen containing a rare gas such as krypton and xenon derived from an air liquefaction separation device. A high-purity purification system for removing impurities such as hydrocarbons and oxygen remaining in the liquid rare gas concentrated in the rough purification system, A rare gas refining apparatus, characterized in that a self-pressurizing storage tank for temporarily storing the liquid rare gas obtained in the crude refining system and introducing it into the highly pure refining system is installed between the system and the system. . 6. The rare gas refining apparatus according to claim 5, wherein the high-purity refining system includes a halogen-based impurity removing apparatus using a getter that removes halogen-based impurities in the rare gas. . 7. A crude purification system for obtaining a liquid mixture of krypton and xenon by removing most of oxygen and hydrocarbons in liquefied oxygen containing krypton and xenon derived from an air liquefaction separation device. In a rare gas purification apparatus comprising a highly pure purification system for removing impurities such as hydrocarbons and oxygen remaining in a liquid mixture concentrated in the crude purification system and rectifying and separating krypton and xenon, Between the crude purification system and the highly pure purification system, the liquid rare gas obtained in the roughly purification system is temporarily stored, and a self-pressurized storage tank for introducing the pressurized rare gas into the highly purified system is installed, and An apparatus for purifying noble gases, characterized in that a halogen-based impurity removing device using a getter for removing halogen-based impurities is installed in front of a rectification column for rectifying and separating krypton and xenon. 8. An apparatus for purifying and separating krypton and xenon from liquefied oxygen containing krypton and xenon derived from an air liquefaction separation apparatus, wherein a concentration column for concentrating krypton and xenon in the liquefied oxygen into a liquid at the bottom of the column. A methane purge tower for purging methane contained in the bottom liquid of the concentrating tower from the top with oxygen gas, a vaporization means for vaporizing the bottom liquid of the methane purge tower, and a carbonization in the gas vaporized by the vaporizer. A first catalytic reaction tube for reacting hydrogen with oxygen, a first adsorber for adsorbing and removing water and carbon dioxide produced by the reaction in the first catalytic reaction tube, and a gas after the derivation of the first adsorber A deoxidizing tower for cooling the gas, a condenser at the top of the tower, and an evaporator at the bottom of the tower, and rectifying the gas cooled by the cooling means to remove oxygen gas in the gas from the top of the tower. And the deoxidation A self-pressurized storage tank for temporarily storing the bottom liquid of the column, a vaporization means for vaporizing the liquid that is pressurized by the self-pressurized storage tank, and hydrocarbons and oxygen contained in the vaporized gas. A second catalytic reaction column for reaction, a second adsorber for adsorbing and removing water and carbon dioxide produced by the reaction in the second catalytic reaction column, and a hydrogenation for adding hydrogen to the gas after the second adsorption step is derived. Means, a third catalytic reaction tube for reacting the hydrogen added by the hydrogen adding means with oxygen contained in the gas, and a drying means for removing water produced by the reaction in the third catalytic reaction tube , A gas-liquid separation means for cooling and liquefying the dried gas to separate hydrogen that is not liquefied, a vaporization means for vaporizing a liquid derived from the gas-liquid separation means, and a halogen-based impurity in the vaporized gas A halogen-based impurity removing means using a getter, Liquefaction means for cooling and liquefying the gas derived from the nitrogen-based impurity removal means, and a separation and rectification column for rectifying the liquefied gas liquefied by the liquefaction means to derive xenon from the tower bottom and krypton from the tower top. Noble gas refining device characterized by