JP2001248793A - Adsorption type gas storing container and activating method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adsorption type gas storing container capable of certainly removing impurities from the interior of the container. SOLUTION: A container filled with a solid phase physical adsorbing medium for adsorbing gas to be stored is provided with two container valves. Purge gas such as helium is inducted from the first container valve and is derived from the second container valve to be circulated in the container. In such a situation, activating and removing impurities are conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adsorption type gas storage container and, more particularly, to an adsorption type gas storage container for holding and storing a gaseous compound such as various hydrides and halides by adsorbing the same on a solid phase physical adsorption medium. For containers.

[0002]

2. Description of the Related Art Gas compounds such as hydrides and halides are used in the field of semiconductor manufacturing and the like. Since many of these gaseous compounds are toxic and highly reactive, the storage, transportation, and supply of these gaseous compounds include:
Much attention has been paid to safety.

In order to safely store such a gaseous compound, an adsorption type gas storage container which stores a gaseous compound in a state where the gaseous compound is adsorbed on a solid phase physical adsorption medium (adsorbent) filled therein has recently been used. It has become to. For example, activated carbon is used as an adsorbent for arsine and boron trifluoride, and zeolite is used as an adsorbent for phosphine. This adsorption type gas storage container prevents gas leakage during storage and transport by adsorbing and storing gas at atmospheric pressure or lower at around room temperature, and when using gas, the container is evacuated. By pulling, the gas is desorbed from the adsorbent and taken out.

[0004]

The conventional adsorption-type gas storage container has only one container valve, which is a gas outlet, so that it takes a great deal of time to activate the adsorbent and remove impurities. I needed it. For example, an adsorbent activated in advance under predetermined conditions is filled in a container in an air environment or a glove box, and a container valve is attached to the container. The impurities mixed in the inside were removed.

[0005] However, it is difficult to completely remove impurities adsorbed on the adsorbent, for example, atmospheric components such as trace amounts of water and carbon dioxide, only by heating and vacuuming. It will take time.

Accordingly, an object of the present invention is to provide an adsorption-type gas storage container capable of reliably removing impurities from the inside of the container.

[0007]

In order to achieve the above object, the adsorption type gas storage container of the present invention is provided with two container valves in a container filled with a solid phase physical adsorption medium for adsorbing a gas to be stored. It is characterized by: Further, the activation method of the adsorption-type gas storage container of the present invention is the activation method of the adsorption-type gas storage container, wherein a purge gas such as helium is used.
Introduced from one of the container valves, characterized in that the solid phase physical adsorption medium is heated while flowing through the container derived from the other container valve, especially when the purge gas flows,
It is characterized in that the activation operation is performed until the derived impurities in the purge gas become 0.1 ppm or less.

[0008]

FIG. 1 is a sectional view showing an embodiment of an adsorption type gas storage container according to the present invention. This adsorption type gas storage container is provided with container valves 12 and 13 at both axial ends of a cylindrical container body 11 filled with an adsorbent 10 made of activated carbon or zeolite as a solid phase physical adsorption medium. . The container body 11 can be formed of the same material and surface treatment as the conventional adsorption type gas storage container, and the same as the conventional container valve can be used for the container valves 12 and 13. The filling of the adsorbent 10 into the container body 11 is as follows.
This can be performed from the opening portion from which one of the container valves is removed. The positions of the container valves 12 and 13 are arbitrary, but are preferably provided at both ends of the container main body 11 so as to be suitable for gas flow.

The activation of the adsorbent filled in the adsorption-type gas storage container formed as described above is performed by connecting a purge gas supply pipe to one container valve 12 and connecting the purge gas supply pipe to the other container valve 13 via a gas outlet pipe. This can be performed by connecting an analyzer and heating the adsorbent while flowing a purge gas, for example, helium at an appropriate flow rate from the container valve 12 side to the container valve 13 side. The heating of the adsorbent can be carried out by heating with a heater or the like from the outside of the container body, or by introducing a heated purge gas.

By circulating the purge gas while the adsorbent 10 is heated in this way, the adsorbent 10 can be activated and impurities such as water and carbon dioxide adsorbed on the adsorbent 10 can be effectively removed. And drain it. Then, the concentration of impurities in the gas discharged from the container valve 13 side, for example, the concentration of moisture is continuously measured. Terminate the removal. Thus, activation and impurity removal can always be performed under constant conditions, so that variations between containers to be processed can be almost eliminated.

After completion of the heating and purging, a vacuum pump is connected to one of the container valves, the other container valve is closed, and in this state, the inside of the container is evacuated to a predetermined degree of vacuum, so that hydride or halogen is removed. The pretreatment for filling a gaseous compound such as a compound is completed. The filling of the gaseous compound may be performed from one container valve as in the conventional case.

Further, by removing impurities to the utmost extent as described above, moisture and the like contained in the gaseous compound to be filled strongly adsorb to the adsorbent. The amount of impurities can be reduced. That is, the gaseous compound can be purified only by filling the gaseous compound into the adsorption type gas storage container.

[0013]

EXAMPLES A conventional container having the same capacity and one container valve and a container of the present invention having two container valves were prepared. For the conventional container, as described above, after pre-activated adsorbent was filled in the container in the glove box, a pretreatment was performed in which a container valve was attached and evacuation was performed while heating to 90 ° C. . In the container of the present invention, after the container is filled with the adsorbent, the adsorbent is heated to 100 ° C. while flowing helium as a purge gas at a rate of 1 liter per minute, and a heating and purging is performed to activate the adsorbent. After removing the impurities, the inside of the vessel was evacuated to complete the pretreatment.

After filling the same amount of arsine in each of the pretreated containers, the inside of the container is evacuated assuming use to extract arsine, and the water concentration in the extracted arsine is continuously measured by an analyzer. Was measured. Figure 2 shows the result.
Shown in

As is apparent from FIG. 2, in the conventional container, the water adsorbed on the adsorbent was desorbed due to a decrease in pressure for taking out arsine, and the water concentration was on the order of sub-ppm. On the other hand, in the container of the present invention, even when the pressure was reduced, the water concentration was hardly changed at 0.1 ppm or less. Therefore, it can be seen that high quality can be maintained for the entire amount of the filled arsine.

[0016]

As described above, according to the adsorption type gas storage container of the present invention, impurities adsorbed on the adsorbent can be efficiently removed. Further, by measuring the impurity concentration and terminating the operation, the impurities can be removed under certain conditions.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of an adsorption-type gas storage container according to the present invention.

FIG. 2 is a view showing an experimental result of an example and showing a relationship between a pressure in a container and a water concentration.

[Explanation of symbols]

 10 adsorbent, 11 container body, 12, 13 container valve

Claims (3)

[Claims] 1. An adsorption type gas storage container characterized in that a container filled with a solid phase physical adsorption medium for adsorbing a gas to be stored is provided with two container valves. 2. The method for activating an adsorption-type gas storage container according to claim 1, wherein a purge gas such as helium is introduced from one of the container valves and is discharged from the other while flowing through the container. A method for activating an adsorption type gas storage container, comprising heating a solid phase physical adsorption medium. 3. The method for activating an adsorption-type gas storage container according to claim 2, wherein the activation operation is performed until the impurities in the purge gas derived from the purge gas flow are reduced to 0.1 ppm or less.