KR100925813B1 - Method and apparatus for removing moisture from ammonia gas - Google Patents

Abstract

The present invention relates to an apparatus and a method for purifying high purity ammonia gas (H ₂ O impurities: 0.5 to 2 ppm) to ultra high purity (less than 10 ppb of H ₂ O impurities).

To this end, the present invention includes a pair of purification towers connected in parallel on the introduction pipe and the introduction pipe through which the ammonia source gas and the refinery gas are introduced and derived, and are respectively filled with a catalyst layer made of a metal oxide; A hydrogen regeneration gas supply source for supplying hydrogen regeneration gas to the outlet side of the refining tower is connected, and a hydrogen regeneration gas discharge pipe is connected to the inlet side of the refining tower to supply hydrogen regeneration gas to the catalyst layer inside the refining tower. Wealth; It is selectively installed on the inlet pipe and the outlet pipe of the refinery tower for introducing and deriving ammonia source gas and purified gas and supplying and blocking hydrogen regeneration gas to open and close the flow path of ammonia source gas, purified gas and hydrogen regeneration gas. Providing ammonia gas water purification device and method comprising a plurality of flow rate and pressure regulating valve, to fill the ammonia gas in the field, using the ultra-high-purity ammonia in the electronic and semiconductor industry, especially LED or solar cell industry It helps to minimize the generation of by-products.

Ultra high purity, ammonia gas, water purification method, water purification device, water removal

Description

Ammonia Gas Water Purification Apparatus and Method {METHOD AND APPARATUS FOR REMOVING MOISTURE FROM AMMONIA GAS}

The present invention relates to a method for purifying high purity ammonia gas with ultra high purity, and more particularly, by supplying hydrogen regeneration gas to a refining tower to regenerate the refining capacity of the refining tower, water (H ₂ O) impurities are 0.5 to The present invention relates to an ammonia gas water purifying apparatus and a method for purifying the high-purity large-capacity ammonia gas having a high purity of 2 ppm with a high purity ammonia gas having less than 10 ppb of water impurities.

In addition, as a catalyst for removing water used in a purification tower according to the present invention, a manganese oxide, magnesium oxide, calcium oxide, or a mixture of ammonia gas water purification apparatus for removing water in a large amount of ammonia gas and a mixture thereof, It is about.

In general, GaN is widely used as a material for semiconductor lasers and light emitting diode (LED) devices operating in the blue violet and ultraviolet regions, and is a nitrogen source for manufacturing (Ga, Al, In) N materials among III-V semiconductor compounds. Since ammonia has a higher partial pressure than raw materials of group III-V compounds, the purity of impurities is very important. In addition, a SiN film is coated for the production of an anti-reflection film in solar cells. Recently, remote plasma-enhanced chemical vapor deposition (PECVD), which activates only ammonia gas through plasma, has been used. This also activates only ammonia gas, so the purity of the impurities is important. Therefore, ammonia gas widely used in the electronics and semiconductor industries, etc. needs to be purified to ultra high purity in which each impurity concentration is 10-50 ppb or less, including oxygen impurities.

Since the commercialization of white LEDs in the 1990s, the demand for white LEDs has exploded, and the use of ammonia gas has been increasing rapidly as solar cell research is actively carried out due to energy or environmental issues.

According to this industrial environment, various impurities of ammonia gas (O ₂ , H ₂ , N ₂ , CO, CO ₂ , other metals, oils) can be reduced to 10-50 ppb by using liquefaction point or non-point difference and zeolite. Metal impurities are also removed at several ppbw, but due to hydrophilicity of ammonia, secondary pollution, and gas mobile phase contamination, it is difficult to remove moisture from ammonia gas itself. Therefore, it is suitable to remove moisture impurities below 10 ppb at the site of use of ammonia gas.

At present, the water removal method of ammonia gas has been adopted to remove water by using zeolite (MS 4A, 5A, etc.) or by using manganese oxide or getter method.

However, due to a growing field of ammonia gas usage time usage hundreds purification methods used to date, given that in reaching Nm ³ / hr 5 - its capacity is very low, as low capacity refinery in more than 100 Nm ³ / hr and In the case of high-capacity purification of several hundred Nm ³ / hr at least 100, the purification efficiency is reduced due to the large capacity, and there are disadvantages in that a lot of problems occur in the production and operation.

Therefore, the present invention has been made to overcome the above problems, by regenerating the purification capacity of the purification tower with hydrogen regeneration gas, by allowing the purification of high-purity large-capacity ammonia gas into ultra-high purity ammonia gas, The purpose of the present invention is to provide an ammonia gas water purifying device and a method for purifying the ammonia gas, which are not only able to increase efficiency in the refining process, reduce manufacturing and operating costs, but are also easy to maintain.

In order to achieve the above object, the present invention provides an ammonia gas water purification apparatus for removing water impurities contained in the source gas from the ammonia source gas and purifying it into ultra-high purity ammonia purified gas, wherein the ammonia gas is introduced and derived. A pair of purification towers connected in parallel on the inlet pipe and the outlet pipe, and each having a catalyst layer made of a metal oxide; The regeneration gas supply pipe and the regeneration gas discharge pipe for supplying and discharging the hydrogen regeneration gas are connected to the derivation pipe and the introduction pipe of the refining tower, thereby supplying the regeneration gas in the reverse direction to the inside of the refining tower to regenerate the refining capacity of the refining tower. A reproducing unit; A plurality of inlet valves and outlet valves selectively installed on the inlet pipe and the outlet pipe of the tablet tower to open and close the flow path for introducing and deriving ammonia gas; It is selectively installed on the regeneration gas supply pipe and the discharge pipe, provides ammonia gas moisture purification apparatus comprising a; a plurality of flow rate and pressure valves for opening and closing the flow path for the supply and shutdown of hydrogen regeneration gas.

In addition, the present invention is a method for purifying ammonia gas to regenerate the refining capacity of the purification tower by supplying a regeneration gas to the ammonia gas purification tower, a purified ammonia feed gas to the purification tower while being purified from the purification tower derived Detecting a concentration of moisture impurities in the ammonia purified gas and checking whether the detected concentration of moisture impurities in the ammonia purified gas exceeds a moisture reference value that is an ultra high purity standard; When the concentration of moisture impurities in the detected ammonia purification gas exceeds the moisture reference value for ultra-high purity purification, the supply gas is shut off and the operation of the purification tower is stopped. A second step of heating the hydrogen regeneration gas; And a third step of adsorbing and removing the water impurities in the catalyst layer by supplying hydrogen regeneration gas heated in the reference temperature in a reverse direction to the purification tower.

According to the present invention, it has a simple structure and is easy to install, requires little operation cost, and the ultra-high purity of less than 10 ppb removes water from ammonia source gas even at high capacity refining by the selective operation of the refinery tower. There is an effect that can be purified.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a reference diagram illustrating a configuration example of a catalyst layer mounted on the purification tower of FIG. 1. 3 is a diagram illustrating an internal configuration of a liquefier connected to the derivation pipe of FIG. 1. 4 is an operation flowchart illustrating a regeneration process in the ammonia gas water purification method according to an embodiment of the present invention.

1 is a schematic configuration diagram of an ammonia gas moisture purification apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the ammonia gas water purifying apparatus according to the present invention is supplied with a raw material gas supplied from an ammonia source gas supply source 55, and a pair of purification towers 10 for purifying water of ammonia gas at room temperature. 20, and a regeneration unit 30 for regenerating the hydrogen regeneration gas in the reverse direction through the refining tower to regenerate the catalyst layer filled in the refining tower, and is selectively installed on the inlet pipe and the outlet pipe of the refining tower. A plurality of inlet and outlet valves (51a-51c, 52a-52d) for opening and closing the flow path for the introduction and derivation of ammonia gas, and selectively installed on the regeneration gas supply pipe and discharge pipe to supply and shut off hydrogen regeneration gas It comprises a plurality of flow control valves (33a, 33b, 34a, 34b) and pressure control valves (34c, 34d) for opening and closing the flow path for.

A plurality of pressure regulating valves 34c, 34d, 52c, and 52d may break or deteriorate the purification towers 10 and 20 due to a sudden pressure change when gas is introduced into or extracted from the purification towers 10 and 20. Is configured to open and close slowly to prevent, a plurality of flow control valves (33a, 33b, 34a, 34b) is configured to properly adjust the flow rate of the gas flowing into the purification tower (10,20). In addition, each of the valves 33a, 33b, 34a-34d, 51a-51c, 52a-52d described above will be operated manually when refining a small amount of gas, and automatically operated when refining a large amount of gas. This would be desirable. Each valve may also be actuated by pneumatic, hydraulic, or electrical signals.

The ammonia source gas supply source 55 is provided with a vaporization heater 57 so that the ammonia source gas supply source 55 can be maintained at an appropriate temperature (about 80-200 ° C) so that the gaseous ammonia source gas is supplied at a sufficient flow rate by heating.

The pair of refinery towers 10 and 20 may include inlets 10a and 20a and outlets on the inlet pipe 51 through which the ammonia source gas is introduced and the outlet pipe 52 through which the ammonia purified gas 53 is drawn. 10b and 20b are connected in parallel, respectively, and catalyst layers 11 and 21 made of metal oxide are respectively filled therein, and a plurality of inlet valves 51a to 51c and outlet valves are selectively provided on the inlet pipe and the outlet pipe. 52a-52d are provided to open and close the flow path for introducing and deriving ammonia gas. When the pair of tablet towers 10 and 20 have a small capacity, one of the pair of tablet towers performs the purification operation, and the other purification tower alternately performs the regeneration operation. In addition, in the case of a large capacity, both of the purification operation may proceed.

The catalyst layer is a manganese oxide (MnO) catalyst layer, magnesium oxide (MgO) catalyst layer, calcium oxide (CaO) catalyst layer, a catalyst layer mixed with manganese oxide (MnO) and magnesium oxide (MgO), manganese oxide (MnO) and calcium oxide ( One of the catalyst layers mixed with CaO) and the catalyst layer mixed with manganese oxide (MnO), magnesium oxide (MgO), and calcium oxide (CaO) is charged, wherein each catalyst layer is introduced into the purification towers 10 and 20. The moisture contained in the ammonia source gas supplied to the spheres 10a and 20a is adsorbed and removed.

The regeneration unit 30 is connected to the hydrogen regeneration gas supply source 31 for supplying hydrogen regeneration gas to each outlet port (10b, 20b) side of each of the purification tower (10, 20) through the regeneration gas supply pipe 36 Regeneration gas discharge pipe 35 for hydrogen regeneration gas is communicated to the inlet (10a, 20a) side of the purification tower (10, 20), and a plurality of selectively on the regeneration gas supply pipe 36 and the discharge pipe (35) Flow rate and pressure valves (33a, 33b, 34a-34d) are installed to open and close the flow path for supplying and shutting off hydrogen regeneration gas. At this time, the regeneration gas supply pipe 36 is branched from the induction pipe 52 and the regeneration gas discharge pipe 35 is branched from the introduction pipe 51 and the reverse direction (induction of the purification tower) in the purification tower (10, 20) Hydrogen regeneration gas can be supplied from the sphere to the inlet direction).

Meanwhile, the regeneration unit 30 connects the heater 32 between the hydrogen regeneration gas supply source 31 and the outlet ports 10b and 20b of the refining towers 10 and 20, thereby regenerating the catalyst for hydrogen regeneration. It is configured to supply by heating to the range of possible reference temperature. The hydrogen regeneration gas is preferably heated to a temperature range of 150 to 400 ℃, preferably 200 to 400 ℃. In addition, the concentration of hydrogen supplied from the hydrogen regeneration gas source 31 in the purified gas may be about 2 to 10%. In addition, the regeneration unit 30 may include a nitrogen gas supply source including hydrogen as a hydrogen regeneration gas supply source.

The outlet of the outlet pipe 52 connected to the purification towers 10 and 20 is branched on one side thereof, one of the branch pipes is connected to the electronic / semiconductor LED process side, and the other branch pipe is connected to the liquefier 54. Connected is configured to produce a purified liquefied gas (56).

3 is a reference diagram illustrating a configuration example of a catalyst layer charged in the purification tower of FIG. 1.

(a) illustrates the case where one type of catalyst layer (11, 21) is filled in each purification tower (10, 20), manganese oxide (MnO) catalyst layer, magnesium oxide (MgO) catalyst layer, calcium oxide (CaO) It can be configured to any one selected from the catalyst layer).

(b) illustrates the case where two types of catalyst layers 12, 13, 22, 23 are filled in each of the purification towers 10, 20, and manganese oxide (MnO) and magnesium oxide (MgO) are mixed. The catalyst layer, manganese oxide (MnO) and calcium oxide (CaO) can be any one selected from the mixed catalyst layer. In this case, the upper part of the purification tower is filled with a manganese oxide (MnO) catalyst layer and the lower part is preferably filled with a magnesium oxide (MgO) catalyst layer or a calcium oxide (CaO) catalyst layer.

(c) illustrates the case where three types of catalyst layers 14-16 and 24-26 are mounted in each of the purification towers 10 and 20, and manganese oxide (MnO), magnesium oxide (MgO) and oxidation Calcium (CaO) may be mixed with the catalyst layer. In this case, it is preferable that the top of the purification column is filled with a manganese oxide (MnO) catalyst layer, and a magnesium oxide (MgO) catalyst layer and a calcium oxide (CaO) catalyst layer are sequentially charged below.

In each of the above cases, the catalyst layer mounted on the purification tower is made of a catalyst material having a flow rate of 5 to 90 wt% of metal oxides (MnO, MgO, CaO) on a silica carrier or silica binder. In terms of economics and efficiency, it will be preferable that the content of the metal or metal oxide is 30 to 80wt%. In addition, the specific surface area of the catalyst is 10 ~ 1000m ² / g, the size of the catalyst particles is 1 ~ 5mm but preferably the specific surface area of the catalyst is 50 m ² / g or more, the catalyst particle size is 3 mm or more. Here, the catalyst in the form of powder of 1 mm or less may be used by mixing Teflon and silica particles to prevent the pressure drop.

The catalyst used in the present invention may be prepared by impregnation or precipitation (precipitation) based on silica, or by using a binder.

FIG. 2 is an exemplary internal configuration diagram of a liquefier connected to the derivation pipe of FIG. 1, and as shown in FIG. 3, the liquefier 54 has a buffer space so that ammonia purified gas introduced into the liquefier is stagnant. And a buffer 54b for lowering the temperature of the ammonia purifying gas to liquefy the purifying gas, wherein the cooling circuit 54a is a spring tube that increases the cooling time and the contact surface of the ammonia purifying gas. 54c is provided inside and comprised.

The operation principle and purification method of the ammonia gas water purification device according to the present invention configured as described above will be described in detail as follows.

4 is an operation flowchart illustrating a regeneration process in the ammonia gas water purification method according to an embodiment of the present invention, which is a regeneration process performed in the water purification apparatus of ammonia gas as shown in FIG.

As shown in Figure 4, the ammonia gas water purification method according to the present invention, when at least one purification tower is purified operation by supplying ammonia source gas to the inlet side of the purification tower while the outlet side of the purification tower The first step (S101-S103) of detecting the concentration of moisture impurities in the ammonia purified gas and checking whether the detected concentration of moisture impurities in the ammonia purified gas exceeds the moisture reference value, which is a standard of ultra-high purity, and the detected A second step of heating the hydrogen regeneration gas of the hydrogen regeneration gas source to a reference temperature capable of regenerating the catalyst after stopping the operation of the purification tower when the concentration of the water impurities in the ammonia purification gas exceeds the moisture reference value for the ultra high purity purification. (S104-S106) and the hydrogen regeneration gas heated to the reference temperature from the outlet of the upper part of the refinery column to the inlet side of the lower part of the refinery column The third step (S107) of regenerating the purification tower by removing water impurities contained in the catalyst layer of the purification tower is performed, and after the purification tower regeneration by the hydrogen regeneration gas of the third step is performed, The fourth step S108 of cooling at room temperature may be further performed.

In the regeneration process according to the present invention, the residence speed of the ammonia feed gas passing through the catalyst bed of the purification tower is preferably 5,000 to 20,000 / h, the temperature of the purification tower is maintained at room temperature, and the ammonia feed gas is converted into MnO, MgO and Moisture can be removed by passing through the catalyst layer of any one of CaO, through a catalyst layer mixed with MnO + MgO or MnO + CaO, or through a catalyst layer mixed with MnO + MgO + CaO, each of the above In the catalyst layer of, water is removed by the following reaction formula.

<Scheme>

MnO + H ₂ O → Mn (OH) ₂ , MgO + H ₂ O → Mg (OH) ₂ , CaO + H ₂ O → Ca (OH) ₂

This method detects the concentration of moisture impurity contained in the ammonia purifying gas and if the detected concentration is 5ppb or more, which is a predetermined moisture reference value for ultra-high purity purification, the hydrogen regeneration gas is heated by a heater at a temperature of 200 to 400 ° C. After heating up to and supplying to the refinery column in the reverse direction with ammonia gas, the water impurities of the catalyst layer mounted on the refinery tower is removed and then discharged to the regeneration gas discharge pipe through the inlet of the refinery tower to regenerate the catalyst in the refinery tower. Will be.

That is, in the water purification process apparatus and method according to an embodiment of the present invention, when the purification tower is started and purification starts, the ammonia source gas source 55 is introduced into the gas phase by heating the ammonia source gas through the vaporization heater 57. Through the pipe 51 is introduced into the inlet (10a, 20a) of each of the purification tower (10, 20), the source gas introduced into the purification tower (10, 20) is a catalyst layer filled in the inside of the purification tower, That is, moisture impurities are removed while passing through any one of the catalyst layers of MnO, MgO, CaO, MnO + MgO, MnO + CaO, MnO + MgO + CaO. At this time, the ammonia source gas passing through the purification towers 10 and 20 is in a temperature range of 0 to 80 ° C., and in a normal case, passes to room temperature. At this time, the residence speed of the raw material gas passing through the purification towers 10 and 20 may be about 5,000 to 15,000 / h, and thus a large capacity (5,000-15,000 / h) of raw material gas passes through the purification towers 10 and 20. Even though the catalyst layer of the present invention is composed of manganese oxide, magnesium oxide, calcium oxide, etc., there is an advantage that the purification operation can be performed very smoothly without increasing the size of the purification towers 10 and 20.

Finally, the raw material gas purified in the ultra high purity in the purification towers 10 and 20 is supplied to each customer through the derivation pipe 52.

On the other hand, in the process of purifying the ammonia source gas by the purification tower (10, 20), if the concentration of the water impurity is detected to be 5ppb or more of the ultra-high purity water reference value, the purification process of the purification tower (10, 20) is The hydrogen regeneration gas flow path which is temporarily suspended and leads to the hydrogen regeneration gas supply source 31 is opened and supplied to the heater 32 side.

The hydrogen regeneration gas is heated to a temperature of 200 to 400 ° C. at room temperature by the heater 32, and the heated hydrogen regeneration gas is purified through the outlets 10b and 20b of the purification towers 10 and 20. It is introduced into (10,20) and is conveyed backward from the top of the purification tower (10,20) to the bottom.

As this hydrogen regeneration gas passes through the purification towers 10 and 20, the water adsorbed on the catalyst layer of the purification tower is removed, thereby regenerating the purification capacity.

Then, the hydrogen regeneration gas is discharged through the regeneration gas discharge pipe 35 communicated with the introduction ports 10a and 20a of the refining towers 10 and 20, and the inside of the refining towers 10 and 20 for a predetermined time. By cooling to room temperature, the regeneration process is completed.

When the refining capacity of the refining towers 10 and 20 is regenerated as described above, the refining operation of the raw material gas is repeated again.

Table 1 below is a result of analyzing water impurities after operating the ammonia gas water purification device of the present invention.

Type of catalyst Before refining After purification Manganese oxide 0.5 ~ 1 N.D Magnesium oxide 0.5 ~ 1 N.D Calcium oxide 0.5 ~ 1 N.D Manganese Oxide + Magnesium Oxide 0.5 ~ 1 N.D Manganese Oxide + Calcium Oxide 0.5 ~ 1 N.D Manganese Oxide + Magnesium Oxide + Calcium Oxide 0.5 ~ 1 N.D

The moisture analyzer used to obtain the result table is MTO-LP, the first time after 24 days after the operation of the ammonia water purifier of the present invention was detected, the water was 80ppb after 7 days It could be confirmed that the increase. Purification catalysts (MnO, MgO, CaO) used in the present invention is stable to ammonia gas, so the catalyst replacement cycle can be used for 1 to 10 years.

In the above, the present invention has been shown and described with respect to certain preferred embodiments. However, the present invention is not limited to the above-described embodiments, and those skilled in the art to which the present invention pertains can vary as many without departing from the spirit of the technical idea of the present invention described in the claims below. Changes may be made.

1 is a schematic configuration diagram of an ammonia gas moisture purification apparatus according to an embodiment of the present invention.

FIG. 2 is a reference diagram illustrating a configuration example of a catalyst layer mounted on the purification tower of FIG. 1.

3 is a diagram illustrating an internal configuration of a liquefier connected to the derivation pipe of FIG. 1.

4 is an operation flowchart illustrating a regeneration process in the ammonia gas water purification method according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10,20: refinery tower 10a, 20a: inlet

10b, 20b: outlet 11 ~ 16,21 ~ 26: catalyst bed

30: regeneration unit 31: hydrogen regeneration gas supply source

32,57: Heater 33a, 33b, 34a, 34b: Flow control valve

34c, 34d: Pressure regulating valve 35: Regeneration gas discharge pipe

36: regenerative gas supply pipe 51: introduction piping

51a-51c: Inlet valve 52a-52d: Outlet valve

52: derived piping 53: ammonia purification gas

54: liquefier 54a: cooling circulator

54b: shock absorber 54c: spring tube

55 ammonia source gas source 56 refined liquefied gas

Claims (9)

In the ammonia gas water purifying apparatus which removes moisture impurities contained in the source gas from the ammonia source gas and purifies it into ultra-high purity ammonia purification gas, A pair of purification towers connected in parallel on the introduction pipe and the discharge pipe through which ammonia gas is introduced and derived, and each having a catalyst layer made of a metal oxide; A regeneration unit communicating with a regeneration gas supply pipe and a regeneration gas discharge pipe for supplying and discharging hydrogen regeneration gas to the derivation pipe and the introduction pipe of the refining tower, and supplying hydrogen regeneration gas to the inside of the refining tower in a reverse direction; A plurality of inlet valves and outlet valves selectively installed on the inlet pipe and the outlet pipe of the tablet tower to open and close the flow path for introducing and deriving ammonia gas; And a plurality of flow rate and pressure control valves selectively installed on the regeneration gas supply pipe and the discharge pipe to open and close a flow path for supplying and blocking hydrogen regeneration gas. The catalyst layer is a manganese oxide (MnO) catalyst layer, magnesium oxide (MgO) catalyst layer, calcium oxide (CaO) catalyst layer, a catalyst layer mixed with manganese oxide (MnO) and magnesium oxide (MgO), manganese oxide (MnO) and calcium oxide (CaO) ) Is a mixed catalyst layer, manganese oxide (MnO), magnesium oxide (MgO) and calcium oxide (CaO) mixed catalyst layer, characterized in that any one of the water purification device. The method of claim 1, The regeneration unit is connected to the hydrogen regeneration gas supply source and the outlet port side of the refining tower, ammonia gas moisture, characterized in that configured by further connecting a heater for heating the hydrogen regeneration gas to the refining tower in the range of the reference temperature capable of catalyst regeneration Purifier. The method of claim 1, The outlet pipe of the purification tower is branched one side, one of the branch pipe is connected to the electronic / semiconductor LED process side, the other branch pipe is ammonia gas purification device, characterized in that the liquefier is configured to be connected. The method of claim 1, The liquefier connected to one side of the decommissioning pipe of the refinery tower includes a buffer for providing a buffer space so that the ammonia purified gas introduced into the liquefier is stagnant, and a cooling circulator for liquefying the purified gas by lowering the temperature of the ammonia purified gas. Ammonia gas water purification device characterized in that. The method of claim 4, wherein The cooling circulator is ammonia gas moisture purification device, characterized in that the spring tube is installed inside the increase the cooling time and the contact surface of the ammonia purification gas. delete The method of claim 1, The catalyst layer is ammonia gas moisture purification device, characterized in that made of a catalyst material having a content of metal oxide (MnO, MgO, CaO) of 5 ~ 90 wt% in a silica carrier or silica binder. In the water purification method of ammonia gas using the ammonia gas water purification device according to any one of claims 1 to 5, While supplying and purifying the ammonia source gas to the purification tower, the water impurity concentration of the purified ammonia purified gas derived from the purification column is detected, and the moisture impurity concentration of the detected ammonia purification gas is the ultra high purity standard. A first step of checking whether it exceeds; When the concentration of moisture impurities in the detected ammonia purification gas exceeds the moisture reference value for ultra-high purity purification, the supply gas is shut off and the operation of the purification tower is stopped. A second step of heating the hydrogen regeneration gas; And a third step of supplying hydrogen regeneration gas heated in the reference temperature in a reverse direction to a purification tower to adsorb and remove moisture impurities in the catalyst layer. The method of claim 8, And a fourth step of cooling the inside of the purification tower at room temperature after regeneration of the purification tower by the hydrogen regeneration gas in the third step.

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