KR20020051314A - A purification method of argon gas with high purity by using activated carbon - Google Patents

Abstract

PURPOSE: A refining method using active carbon is provided to attain a high purity argon gas by continuously removing methane gas contained in the argon gas through the adsorption/removal processes of the methane gas. CONSTITUTION: The refining method of high purity argon gas using active carbon comprises the steps of: connecting at least two active carbon adsorbent columns in parallel for liquefying argon gas; adsorbing and removing methane gas contained in the argon gas in a condition of 10 to 30deg.C and 3.5 to 50kgf/cm¬2; regenerating the columns, to which the methane gas is adsorbed, under a vacuum environment; and repeatedly performing the adsorption/removal processes of the regenerated columns.

Description

Purification method of high purity argon gas using activated carbon {A PURIFICATION METHOD OF ARGON GAS WITH HIGH PURITY BY USING ACTIVATED CARBON}

The present invention relates to a method for removing methane gas in argon gas using activated carbon in an argon gas manufacturing process. More specifically, the adsorption / removing ability of the adsorbent to methane gas present in the argon gas discharged from the pressure swing adsorption device is removed. It relates to a purification method that can be efficiently removed for a long time with one kind of activated carbon adsorbent without deterioration.

Conventionally, a PSA (pressure swing adsorption) apparatus, which is a multi-bed adsorption system, is known for separating gas mixtures by selective adsorption using pressure swings for high to low pressure adsorption and desorption. In some cases, the low pressure can be subatmospheric and a variation of the process is defined as vacuum swing adsorption (VSA).

In general, important variables in the removal of impurities using adsorbents include the adsorption amount of how much the adsorbent can adsorb the impurities to be removed and the desorption ability of the adsorbents to easily desorb the adsorbed impurities. Can be mentioned.

The amount of adsorption varies depending on the average pore diameter, specific surface area of the adsorbent, temperature and pressure of the adsorbent gas, and the adsorbent is difficult to regenerate when the adsorbed material is adsorbed with a strong force such as chemical adsorption. It should be easily removable and regenerated.

Accordingly, an object of the present invention is to continuously remove methane gas present in argon gas by effectively performing a methane gas adsorption / removal process and a desorption / regeneration process without using a specific chemical in using activated carbon as an adsorbent. To provide a method for purifying high purity argon gas.

According to the invention,

Argon pressure swing adsorption (PSA) device Hydrogen is introduced to remove oxygen in the argon gas discharged from the outlet, and then oxygen and hydrogen are reacted in the catalytic reactor to convert into water, and then condensed in the cooler to remove and liquefied argon gas In the method for producing a high purity argon gas comprising a,

Connecting two or more activated carbon adsorbent columns in parallel to a line used to liquefy the argon gas;

Argon gas containing methane is adsorbed / removed in some of the columns while passing through the breakthrough time under conditions of 10 to 50 ° C. and 3.5 to 50 kgf / cm ² ;

While the methane gas is adsorbed / removed under the above conditions, the column to which the methane gas is adsorbed is regenerated at 10 to 150 ° C. in a vacuum atmosphere;

The regenerated column is re-inserted into the adsorption / removal process to provide a method for purifying high purity argon gas using activated carbon, characterized in that the adsorption / desorption process is repeated.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention provides a method for producing high purity argon by continuously removing trace amounts of methane present in the argon gas using an adsorbent in the production of high purity argon gas using a PSA device.

In the present invention, two or more adsorbent columns are connected to the rear end of the PSA apparatus. These columns repeat the adsorption / removal and desorption / regeneration processes.

That is, the gas discharged from the pressure swing adsorption (PSA) device outlet is introduced into some of the columns of two or more activated carbon adsorbents to adsorb / remove the methane gas. The methane gas is adsorbed / removed by changing to a column, and the methane gas-filled column repeats the process of desorbing / regenerating methane and then re-injecting the methane gas.

Here, as the gas discharged from the PSA apparatus, as described above, it means that the amount of methane contained less than 1% as impurities in the amount of about 99% by volume or more of argon.

In addition, activated carbon is used in the present invention as an adsorbent for removing methane gas, and other active ingredients may be added. The active ingredient includes, for example, platinum and bromine. It can also be used in combination with other adsorbents.

The type of activated carbon used in the present invention is not particularly limited, but for example, charcoal, coke, coconut shell, natural fiber, synthetic resin such as polyacrylonitrile, rayon and phenol resin, pitch, etc. are used as starting materials. Activated carbon obtained by a conventional method can be used.

In addition, the activated carbon may be, for example, powder form, granule form, pellet form, macaroni form or fiber form, and more preferably in pellet form and fiber form.

These activated carbons may contain various binders, for example, metals.

When the activated carbon is used to adsorb the methane in the argon gas discharged from the PSA device, it is appropriate that the temperature is 10 to 50 ° C. and the pressure is 3.5 to 50 kgf / cm ² .

At this time, the gas is activated and desorbed easily from the adsorbent at a temperature of 50 ° C. or higher, and the amount of adsorption is too small below 10 ° C., and the increase in the amount of adsorption against pressure is not effective even if the pressure is constantly increased. Preferred pressure conditions in the above temperature range is appropriately 3.5 ~ 50kgf / cm ² .

When the gas to be treated is brought into contact with the activated carbon, the line flow velocity of the gas to be treated is, for example, about 1 to 200 cm / sec, preferably about 2 to 150 cm / sec, and more preferably about 5 to 100 cm / sec. The space velocity of the gas to be treated is, for example, about 20 to 500,000 hr ⁻¹ , preferably about 50 to 250,000 hr ⁻¹ , and more preferably about 100 to 150,000 hr ⁻¹ .

Meanwhile, the gas adsorbed methane is vacuum desorbed at a temperature of 10 ~ 150 ℃ to regenerate activated carbon. Vacuum desorption was effective at room temperature, and as the temperature increased, the adsorbed methane was activated to facilitate desorption.

Activated carbon used in the method of the present invention has the advantage that the activated carbon can be efficiently used for a long time by only one filling, since the adsorption / removal process and the desorption / regeneration process are repeatedly performed. The removal rate is excellent.

According to the method of the present invention, since the concentration of methane gas present in the argon gas is reduced to 10 ppm or less and then supplied to the argon liquefaction cooler, methane, which is an impurity, does not condense in the cooler and cause problems such as pipe closure. will be.

Hereinafter, the present invention will be described in detail with reference to Examples, and the following Examples are intended to illustrate the present invention and are not intended to limit the present invention thereto.

Example 1

Experiment for deriving optimum adsorption pressure condition

5 g of activated carbon was charged into two 1/2 inch Фx 100 mm adsorption columns, and the effluent methane concentration was discharged by flowing argon gas containing 152 ppm of methane released from the PSA system at a temperature of 3.5-20 kgf / cm ² at 25 ° C. in 70 ml / min. Analysis by gas chromatography.

The breakthrough time for each pressure condition was measured and the results are shown in Table 1 below.

Pressure (kgf / cm ² ) Breakthrough time (minutes) Comparative Example 1 One 0.5 Inventive Example 1 3.5 4 Inventive Example 2 5 5 Inventive Example 3 10 9 Inventive Example 4 20 17 Comparative Example 2 50 22

As shown in the above Table, the pressure conditions in the adsorption / removal process was found to be 3.5~50kgf / cm ² when the preferred, and in particular 10~20kgf / cm ² effective than before.

Example 2

<Adequate adsorption temperature derivation experiment>

The same procedure as in Example 1 was repeated except that the argon gas to be treated for each temperature described in the following table was measured, and the breakthrough time at this time was measured and shown in Table 2 below.

Temperature (℃) Breakthrough time (minutes) Inventive Example 5 10 10 Inventive Example 6 25 9 Inventive Example 7 50 5 Comparative Example 3 90 <0.5

As shown in the above table, it was confirmed that the reaction temperature in the adsorption / removal process is preferably in the range of 10 to 50 ° C.

Example 3

<Derived desorption temperature derivation experiment>

The same process as in Example 1 was repeated except that argon gas was passed at 10 kgf / cm ² and 140 ml / min for 30 minutes, and the methane concentration after vacuum desorption for each temperature shown in Table 3 was measured, and the results were summarized in Table 3. Indicated.

In this case, 10 ° C. and 50 ° C. were vacuum desorbed for 10 minutes, and 200 ° C. showed vacuum desorption for 30 minutes including a heating time.

Vacuum Desorption Temperature (℃) Methane Gas Concentration (ppm) Inventive Example 8 10 <1 Inventive Example 9 50 <1 Inventive Example 10 150 0 Comparative Example 4 200 0

As shown in the above table, it was found that the reaction temperature at the time of desorption / regeneration was in the range of 10 to 150 ° C.

Example 4

5g each of carbon black, charcoal, charcoal activated carbon (SGA-100), and coal-based activated carbon, each 5g each, and the same as in Example 1 except that 70ml / min was flowed at a pressure of 10kgf / cm ² . The experiment was repeated and the breakthrough time is shown in Table 4 below.

Sorbent type Breakthrough time Remarks Carbon black 5 powder Charcoal activated 7 Granules Charcoal Activated Carbon (SGA-100 *) 9 Granules Coal-based activated carbon 9 Pellets (4mmφ × 6mm)

* Methane adsorption amount of SGA-100: about 0.053ml / g

As shown in the above table, it was confirmed that all applicable to the present invention regardless of the type of activated carbon.

Example 5

<Methane removal effect by repeating adsorption / removal and desorption / regeneration process using one column>

Repeated adsorption / removal of the column that was adsorbed / removed using a single column at room temperature for 10 minutes and then repeated adsorption was repeated 10 times. It is shown in Table 5 below.

Resorption One 2 3 4 5 6 7 8 9 10 Methane Emission Concentration (ppm) 0 0.6 0 0 0.4 0.1 0 0.5 0.1 0

As shown in the table, even if repeated, the methane emission concentration was confirmed to be removed to less than 1ppm without significant change. In addition, visual observation of activated carbon in the column during resorption showed no change in appearance.

Example 6

<Methane gas removal effect when two columns are used alternately>

180g of activated carbon was filled into two 50mmФx 100mm adsorption columns, and argon gas containing 152ppm of methane was passed through a column at 30 ml at a space velocity of 500ml / min for 30 minutes to remove methane, while the other one column was adsorbed. The methane content of the outlet was analyzed by gas chromatography using two columns alternately by desorbing methane under vacuum for 30 minutes. After 12 hours of continuous operation, it was possible to remove methane below 10 ppm.

According to the method of the present invention, when using activated carbon as an adsorbent, methane gas is continuously and efficiently removed by simultaneously performing a methane gas adsorption / removal process and a desorption / regeneration process without supporting any particular chemicals. It can improve the purity of argon gas.

Claims (2)

Argon pressure swing adsorption (PSA) device Hydrogen is introduced to remove oxygen in the argon gas discharged from the outlet, and then oxygen and hydrogen are reacted in the catalytic reactor to convert into water, and then condensed in the cooler to remove and liquefied argon gas In the method for producing a high purity argon gas comprising a, Connecting two or more activated carbon adsorbent columns in parallel to a line used to liquefy the argon gas; Argon gas containing methane is adsorbed / removed in some of the columns while passing through the breakthrough time under conditions of 10 to 50 ° C. and 3.5 to 50 kgf / cm ² ; While the methane gas is adsorbed / removed under the above conditions, the column to which the methane gas is adsorbed is regenerated at 10 to 150 ° C. in a vacuum atmosphere; High purity argon gas purification method characterized by repeating the adsorption / desorption process by re-entering the regenerated column to the adsorption / removal process The method of claim 1, wherein the purified argon gas is liquefied by sending the purified argon gas to the cooler when the concentration of methane gas contained in the argon gas is 10 ppm or less by the adsorption / desorption process.