JP2000317246A - Ammonia recovery method and recovery device - Google Patents

Abstract

(57) [Problem] To develop a method for recovering ammonia from a large amount of gas containing a high concentration of ammonia in a short time and with high yield. SOLUTION: A multitubular adsorber is filled with an ammonia adsorbent, and ammonia is adsorbed and captured by passing an ammonia-containing gas while cooling the adsorbent, and then the multitubular adsorber is heated with a heat medium. The ammonia is desorbed and recovered under reduced pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for recovering ammonia, and more particularly to a method and an apparatus for efficiently recovering ammonia from a large amount of gas containing high-concentration ammonia.

[0002]

2. Description of the Related Art Ammonia is widely used as a raw material in the chemical industry, and is also used for producing nitride films in the production of decorative articles, cemented carbide tools and semiconductors. After these ammonias are used, they are converted into low-value substances or non-value substances as exhaust gas treatments, and some of them are discharged to the atmosphere as they are. Also, depending on the process in which ammonia is used, a large amount of useful ammonia may be exhausted. For example, in the manufacture of a compound semiconductor such as a gallium nitride film, most of the high-purity ammonia used in the semiconductor manufacturing process is left unreacted. Discharged from the device. For this reason, a great deal of cost is required for the ammonia removal treatment. These ammonias are desired to be used not only for effective use of resources but also for environmental science. The present invention relates to a method for efficiently recovering ammonia. Conventionally, ammonia-containing exhaust gas after using ammonia, because ammonia is a relatively inexpensive compound,
Less recovery of ammonia as it is,
It is often discarded by means such as removal and detoxification as exhaust gas treatment. As the ammonia exhaust gas treatment, for example, a combustion treatment method, a wet absorption method, a dry adsorption method, a decomposition treatment method, a combination method of decomposition and dry adsorption, and the like are known. However, they have the following problems.

[0003] In the combustion treatment method, it is said that fuel such as propane is required for the combustion treatment, that the combustion device has a narrow range of application to load fluctuations, and that nitrogen oxides are by-produced with the combustion of ammonia. There are inconveniences. Also,
The wet absorption method using an acidic aqueous solution has a disadvantage that it is difficult to treat the ammonium salt produced as a by-product. Further, in the case of the dry adsorption method in which detoxification is carried out by chemical adsorption, since the adsorbent is expensive, there is an inconvenience that the treatment cost is high in the case of treating a large amount of ammonia.

In the method in which ammonia is brought into contact with an ammonia decomposition catalyst under heating to decompose it into nitrogen and hydrogen, undecomposed ammonia based on chemical equilibrium remains and cannot be completely treated. For this reason, a method is also known in which ammonia is decomposed into nitrogen and hydrogen by contacting it with a decomposition catalyst, and then the undecomposed ammonia is purified with a dry adsorbent. There is a disadvantage that the processing cost is high in the processing of a large amount of gas.

As described above, the methods of treating ammonia as exhaust gas have disadvantages, and none of the methods aim at recovering ammonia as a useful substance. In other words, there is a basic problem that a material useful as a chemical industrial material or a material in semiconductor production is converted into a material having no value or a material having a low value at a cost.

[0006]

On the other hand, in the production of nitride semiconductors, etc., a large amount of high-purity ammonia is used. However, most of them are discharged at a high concentration without being reacted, and the amount thereof is large. Therefore, there is an inconvenience when any of the above-mentioned treatment methods is applied. If such ammonia can be efficiently recovered, it is not only effective use of resources but also from the viewpoint of environmental conservation. However, a method for efficiently recovering ammonia has not yet been proposed. That is, an object of the present invention is to develop a recovery method and a recovery apparatus for efficiently recovering a large amount of ammonia discharged at a high concentration.

[0007]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, a plurality of adsorption tubes filled with an adsorbent such as synthetic zeolite and activated carbon are built in, and the adsorption tubes It has been found that ammonia can be efficiently adsorbed and trapped by passing a gas containing ammonia while cooling the multitubular adsorber having a configuration in which a heat medium can be circulated outside the heat exchanger with the heat medium. Also,
It has been found that ammonia can be recovered in a short time and with good yield by desorbing ammonia under reduced pressure while heating the multitubular adsorber having adsorbed ammonia with a heat medium,
The present invention has been reached.

That is, the present invention relates to a multi-tube adsorber having a structure in which a plurality of adsorption tubes filled with an adsorbent for ammonia are built in and a heat medium can be circulated outside the adsorption tubes. After ammonia is adsorbed and captured by passing a gas containing ammonia into the adsorption tube of the multitubular adsorber while cooling with, the inside of the adsorption tube is depressurized while heating the multitubular adsorber with a heat medium. A method for recovering ammonia, characterized by maintaining and removing and recovering ammonia. Further, the present invention provides a plurality of multi-tube adsorbers arranged in parallel with a plurality of adsorption tubes filled with an adsorbent of ammonia and having a structure capable of flowing a heat medium outside the adsorption tubes, While sequentially switching the multitubular adsorber and cooling ammonia with a heat medium, a gas containing ammonia is passed through the multitubular adsorber to adsorb and capture ammonia, and then sequentially switch the multitubular adsorber. A method for recovering ammonia, characterized in that the inside of the adsorption tube is kept at a reduced pressure while heating with a heat medium, and ammonia is desorbed and continuously recovered.

Further, the present invention provides a multitubular adsorber having a structure in which a plurality of adsorption tubes filled with an adsorbent for ammonia are built in and a heat medium can be circulated outside the adsorption tubes. After having a pump for depressurizing and exhausting the inside of the adsorption tube of the multitubular adsorber, and while cooling the multitubular adsorber, ammonia is adsorbed and captured by passing gas containing ammonia through the adsorption tube, An ammonia recovery apparatus characterized in that ammonia can be desorbed and recovered while keeping the inside of the adsorption tube under reduced pressure while heating the multitubular adsorber with a heat medium. Furthermore, the present invention has a plurality of rows of multitubular adsorbers arranged in parallel, each having a plurality of adsorption tubes filled with an ammonia adsorbent and having a structure in which a heat medium can be circulated outside the adsorption tubes. A pump for depressurizing and exhausting the inside of the adsorption tube of the multitubular adsorber, and sequentially switching the multitubular adsorber to cool the multitubular adsorber with a heat medium while supplying gas containing ammonia to the multitubular adsorber. After adsorbing and capturing ammonia by passing air through the adsorption tube, it is possible to continuously switch the multitubular adsorber to sequentially recover the ammonia by depressurizing while keeping the inside of the adsorption tube under reduced pressure while heating with a heat medium. An ammonia recovery apparatus characterized in that the apparatus has a configuration that allows the ammonia recovery.

According to the present invention, it is possible to reduce the adsorption capacity by adopting a multi-tube adsorber and forcibly cooling the adsorbent when the adsorbent rises in temperature due to the heat of adsorption and decreases the adsorption capacity when adsorbing ammonia. Can be prevented. In addition, when desorbing the adsorbed ammonia under reduced pressure, it is possible to prevent the temperature of the adsorbent and the desorption speed from being lowered due to the heat of vaporization of the ammonia by forcibly heating, and to reduce the yield of ammonia in a short time. It is a method of collecting well and a collecting device. Also, by adopting such a configuration,
Since a large amount of ammonia can be adsorbed with a small amount of adsorbent and the operation of desorbing the adsorbed ammonia can be performed in a short time, the ammonia recovery device can be downsized. In addition, when the adsorbent is cooled and heated, heat exchange between the adsorbent and the heat medium is performed well, so that no special heat medium is required and the efficiency can be improved by combining cooling water and hot water. Can do well.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The present invention is mainly applied to a method for recovering ammonia from a large amount of gas containing ammonia at a relatively high concentration. The gas containing ammonia in the present invention means a gas containing ammonia in a gas that does not cause a chemical reaction with ammonia in a normal temperature and pressure range, and the gas type is not particularly limited.
For example, it refers to a gas containing ammonia in a gas such as hydrogen, nitrogen, helium, or argon. In addition, the concentration of ammonia in the gas containing ammonia is not particularly limited, and includes any concentration of ammonia from a low concentration to a high concentration.

An example of the multitubular adsorber of the present invention will be specifically described with reference to FIG. In the present invention, the multitubular adsorber 3 is one in which a number of adsorption tubes 4 filled with an adsorbent 5 are provided in one adsorber, and as shown in FIG. It is attached through the plates 8, 8 '. A gas containing ammonia can be circulated in each of the adsorption tubes, and a cooling medium or a heating medium such as hot water or steam is supplied between the adsorption tube 4 and the body portion 9 between the two tube plates through the heat medium inlet 6. From the heat medium outlet 7 so that the adsorbent 5 can be heated and cooled as required. The multitubular adsorber has a structure similar to that used as a multitubular heat exchanger or a multitubular reactor in the chemical industry. These multitubular adsorbers can be used in a single tube, but can also be provided in a plurality of rows in parallel.

In the present invention, the ammonia adsorbent is
A large amount of ammonia can be physically adsorbed,
Any adsorbent that can easily release ammonia depending on operating conditions such as pressure change or temperature change can be used, and is not particularly limited.
As a material satisfying these characteristics, for example, synthetic zeolite (molecular sieves 13X, 5A or the like), silica gel, alumina, activated carbon, or the like is used.

An example of the ammonia recovery apparatus of the present invention will be specifically described with reference to FIG. The present invention is an apparatus comprising a series of multitubular adsorbers, which can be implemented by first performing an ammonia adsorption operation, then stopping the supply of ammonia-containing gas, and performing an ammonia desorption operation. However, by connecting two or more series of multitubular adsorbers in a state that can be switched in parallel and switching between ammonia adsorption capture and desorption operation in each multitubular adsorber, continuous operation is possible. It is preferred to do so. FIG. 1 shows a method in which two series of multitubular adsorbers are provided, and one of the adsorbers performs the operation of adsorbing ammonia while the other adsorber performs the operation of desorbing ammonia. This is an example of a recovery device configured to be able to continuously recover ammonia from a gas containing ammonia. The gas containing ammonia is introduced into the adsorption pipe 4 from the upper part of the adsorber 3 through the ammonia discharge line 1 and the valve 2. At this time, heat of adsorption is generated along with the adsorption of ammonia. By flowing a heat medium such as cooling water between the heat medium inlet 6 and the heat medium outlet 7,
It is possible to prevent a decrease in adsorption capacity due to a rise in temperature.

The gas from which ammonia has been adsorbed and removed is led to an exhaust line 11 via a valve 10. When the ammonia adsorbent adsorbs ammonia and reaches saturated adsorption or near saturated adsorption, valves 2 and 10 are closed and valves 2 ′ and 10 ′ are closed.
Is opened, and the flow of the gas containing ammonia is adsorbed by the adsorber 3 '.
Switch to. Next, the valve 12 is opened, a reduced pressure is suctioned for a short time through the ammonia recovery line 13 by the vacuum pump 14, and the recovered gas at that time is introduced into the surge tank 23 through the valve 15. Thereafter, the valve 15 is closed, the valves 17 and 20 are opened while the vacuum pump 14 is in operation, the pressurizing pump 19 is operated, and the adsorber 3 is heated by flowing hot water or steam, and desorbed. Ammonia tank 21 passes through the buffer ammonia 18
To be collected. The collected ammonia is withdrawn from the valve 22 as needed. After the completion of the ammonia recovery, the suction under reduced pressure is stopped, the adsorber 3 is cooled to a temperature near normal temperature, and an inert gas is introduced from the outlet gas of the adsorber 3 ′ or a pipe provided separately. After returning the inside to normal pressure,
Prepare for the next switch. The recovered gas in the surge tank 23 is introduced into the ammonia discharge line at a small flow rate via the valve 24 and the exhaust gas circulation line 16.

In the present invention, the inner diameter of the adsorption tube used for the adsorber is usually 25 to 300 mm, preferably about 50 to 150 mm. When the diameter is smaller than 25 mm, a small amount of the adsorbent is used, so that a large number of adsorption tubes are required, which not only increases the production cost of the adsorber but also lowers the volumetric efficiency of the adsorber. If it is larger than 300 mm, heat conduction when cooling or heating the adsorbent is disadvantageously deteriorated.

The length of the adsorption tube is usually 250 to 3
000 mm, preferably about 500 to 1500 mm. When the length is shorter than 250 mm, there is a disadvantage that the amount of the adsorbent is small in spite of the complicated structure of the adsorber,
When it is longer than m, there is a disadvantage that the pressure loss becomes large.

The shape of the body of the adsorber is not particularly limited.
However, the shape of the gas introduction portion and the gas discharge portion of the adsorber is preferably made into a bowl shape from the viewpoint of maintaining pressure resistance when ammonia is adsorbed and then desorbed and recovered under reduced pressure after ammonia is adsorbed. From that point, it is preferable that the shape of the body of the adsorber is cylindrical.

The number of adsorption tubes provided in the adsorber is not particularly limited, and is appropriately selected depending on the throughput of ammonia-containing gas, ammonia concentration, thickness and length of the adsorption tube, desired switching time, and the like. Is appropriately set based on the method of arranging the adsorption tubes in the adsorber. In addition, a partition plate or the like for efficiently flowing the heat medium between the adsorption tube and the body of the adsorber may be provided. In addition, the description of the adsorber in the present invention has been described by a method of filling the adsorbent inside the adsorption tube and flowing the heat medium outside the adsorption tube. However, the outside of the adsorption tube can be filled with an adsorbent, and the heat medium can be circulated inside the adsorption tube.
Not practical.

Although the constituent material of the ammonia adsorber is not particularly limited, it is usually considered in consideration of the fact that it does not contaminate the recovered ammonia gas, does not corrode, and has good heat conduction. SUS304, SUS31
6, SUS316L or the like is used.

In the present invention, as the temperature of the adsorbent at the time of adsorbing ammonia, the lower the temperature, the higher the adsorbing ability. However, from the viewpoint of easy cooling, it is usually -30 to 75 ° C., preferably room temperature. ５０50 ° C. In order to cool to such a temperature, the cooled gas can be circulated as a heat medium, but since the gas has a small heat capacity and cannot be rapidly cooled, water or a known antifreeze is used after cooling. Is preferred. The pressure at the time of adsorption is not particularly limited. From the viewpoint that the amount of adsorption increases as the pressure increases and the pressure resistance of the adsorber, the adsorption is performed at normal pressure to about 5 kg / cm ^2. Is determined by the source conditions.

The linear velocity (LV) at the time of bringing the gas containing ammonia into contact with the adsorbent differs depending on the concentration of ammonia and cannot be specified unconditionally.
m / sec or less, preferably 30 cm / sec or less.

In the present invention, the lower the pressure at which ammonia is recovered from the adsorbent after the adsorption of ammonia, the easier the desorption of ammonia becomes, but the pressure is usually 0.1 mm because a vacuum pump having a large exhaust capacity is required. 5-500mm
Hg, preferably about 20 to 300 mHg. The heating temperature of the adsorbent is not particularly limited, and the higher the temperature, the easier the desorption of ammonia is. However, since the evacuation is performed, a very high temperature is not required.
0 ° C, preferably 70 to 150 ° C. In order to heat to such a temperature, the heated gas can be circulated as a heat medium, but since the gas has a small heat capacity and cannot be heated quickly, hot water or steam, or pressurized hot water is used. It is preferable to use steam or pressurized steam. In addition, a heat medium such as a high-boiling hydrocarbon can be used.

As described above, according to the present invention, when ammonia is adsorbed, the adsorbent is forcibly cooled with a heat medium to prevent the temperature of the adsorbent from rising even if the gas contains a large amount of high-concentration ammonia. Adsorption can be performed efficiently. On the other hand, when recovering ammonia, heating with a heat medium while suctioning under reduced pressure prevents the temperature of the adsorbent from lowering due to the vaporization of ammonia, and makes it possible to easily desorb a large amount of adsorbed ammonia in a short time. be able to. The heating of the adsorbent may be performed at a relatively low heating temperature for the desorption operation under reduced pressure, for example, it can be heated with hot water. Therefore, the heating is performed using a combination of cooling water and hot water as a heat medium. Therefore, the device configuration can be simplified.

Further, in the present invention, by making the ammonia adsorption tube relatively thin and forming an adsorber in which a number of adsorption tubes are integrated, heating and cooling can be simplified and facilitated, and cooling and heating of the adsorbent can be performed. Can be done quickly. In addition, this makes it possible to efficiently treat even a gas containing a high concentration of ammonia, and to recover the adsorbed ammonia in a short time with high yield. The ammonia recovered in the present invention can be used as it is as an ammonia raw material, but can be further purified to a higher purity by using a known purification technique, if desired.

[0026]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

(Example 1) (Manufacture of ammonia recovery apparatus) A structure in which 19 SUS316L adsorption tubes having an inner diameter of 108.3 mm and a length of 1500 mm are built in and a heat medium can flow between the adsorption tubes and the body. Were manufactured. Each of the adsorbers was filled with 250 liters of molecular sieves 5A.
In addition, a vacuum pump, a pressure pump, a buffer tank, a surge tank, a recovered ammonia tank, and a cooling water line and a heated water line were connected so as to be switchable, and an ammonia recovery device similar to that shown in FIG. 1 was manufactured. .

(Ammonia Recovery Experiment) Prior to the experiment, the adsorbent was activated as follows. Adsorption tube 4,
Nitrogen gas was passed through 4 ′ to replace the air in the adsorption tube with nitrogen. Next, while maintaining the inside of the adsorption tube at a reduced pressure of 5 mmHg or less with a vacuum pump, hot water at 90 ° C. was circulated outside the adsorption tube and heated for 5 hours. Then, after cooling to room temperature, nitrogen was introduced to return to atmospheric pressure, and the activation was completed.

In the ammonia recovery apparatus, 25
While cooling the inside of the adsorption tube by flowing cooling water of
0.13 of nitrogen gas containing 30% of monia at normal temperature and normal pressure
6m ³/ Min at a flow rate of
Was adsorbed. After continuing ammonia adsorption for 8 hours,
Switch the ventilation of gas containing ammonia to adsorber 3 '
Was. During this time, ammonia flows into the outlet gas of the adsorber 3
Was not found.

While the inside of the adsorption tube 4 was maintained at a temperature around room temperature, the vacuum pump 14 lightly evacuated the air for 1 minute, and the exhaust gas at that time was introduced into the surge tank 23. Next, the exhaust line of the vacuum pump 14 is switched to the buffer tank 18 and the ammonia recovery tank 21 side, and while operating the pressurizing pump 19, the cooling water of the adsorber 3 is supplied by replacing the cooling water with 90 ° C. hot water. The inside of the vessel 4 was heated. Under heating,
A vacuum suction operation was performed for 5 hours to complete the ammonia recovery operation. Next, the supply of hot water was changed to cooling water and cooled to room temperature. Then, a part of the outlet gas of the adsorber 3 ′ was introduced into the adsorber 3 and returned to normal pressure to prepare for switching. Meanwhile, the recovered gas in the surge tank 23 was introduced at a small flow rate into the ammonia discharge line 16 via the valve 24 and the exhaust gas circulation line 16.

The operation of recovering ammonia was repeated 10 times by alternately switching the adsorbers in this manner. As a result, the recovery rate of ammonia was 98% or more. The recovered ammonia contained only 0.15% of nitrogen.

(Comparative Example 1) Inner diameter 472 mm, length 180
2 molecular sieves 5A in one adsorption tube of 0 mm
Fifty liters (filling length 1500 mm) were filled. A heater for electric heating and a heat insulating material were attached to the adsorption tube.
Furthermore, a thermocouple for temperature measurement was provided inside the adsorption cylinder, and an adsorber was manufactured. An ammonia recovery device similar to that of Example 1 was manufactured except that the adsorber in Example 1 was replaced with such an adsorber. A nitrogen gas containing 30% of ammonia was supplied to the ammonia recovery apparatus at normal temperature and normal pressure at 0.136 m ³ /
Vent at a flow rate of min. As a result, the temperature of the adsorbent gradually increases from the top to the bottom, and after two hours,
° C was reached. After 3 hours, outflow of ammonia was observed at the outlet of the adsorption column. Thus, the ammonia adsorption operation was terminated when 3.5 hours had elapsed from the start of the adsorption operation. Attempting to recover ammonia by depressurizing and exhausting with a vacuum pump while electrically heating the adsorption cylinder, and performing a heating operation for 5 hours. Although the temperature of the inner wall of the adsorption cylinder increased, the temperature of the central part of the adsorption cylinder was increased. The rise was small and only 28% of the adsorbed ammonia could be recovered.

[0033]

According to the present invention, the following has become possible. 1. Even in the case of a large amount of gas containing high-concentration ammonia, it can be recovered in a short time with high yield. 2. Since the temperature rise of the adsorbent due to the heat of adsorption during ammonia adsorption can be prevented by forced cooling with a heat medium, the adsorption operation can be performed efficiently in a state where the adsorbent has a high adsorption capacity. 3. When ammonia is desorbed, a decrease in the temperature of the adsorbent due to the heat of vaporization of ammonia can be prevented by forcible heating with a heat medium, so that ammonia can be recovered in a short time and with high yield. 4. Since the heat exchange between the adsorbent and the heat medium is performed well, a special heat medium is not required, and the heat medium can be composed of a combination of water and hot water. 5. Since the operation of adsorbing a large amount of ammonia can be performed with a small amount of adsorbent and the operation of desorbing ammonia can be performed in a short time, the switching time of the ammonia adsorber can be set short. 6. From the above, the device can be simplified and the device can be downsized. 7. Conventionally, ammonia that has been disposed of at a high cost can be recovered with high purity and reused.

[Brief description of the drawings]

FIG. 1 is an example of an ammonia recovery apparatus of the present invention.

FIG. 2 is an example of an adsorber according to the present invention.

[Explanation of symbols]

1 Ammonia discharge line 2, 2 ', 10, 10', 12, 12 ', 15, 17,
20, 22, 24 Valve 3, 3 'Adsorber 4, 4' Adsorption tube 5, 5 'Adsorbent 6, 6' Heat medium inlet 7, 7 'Heat medium outlet 8, 8' Tube plate 9 Body part 11 Exhaust line 13 Ammonia recovery line 14 Vacuum pump 16 Exhaust gas circulation line 18 Buffer tank 19 Pressurizing pump 21 Recovered ammonia tank 23 Surge tank

Claims (8)

[Claims] 1. A multitubular adsorber having a structure in which a plurality of adsorption tubes filled with an adsorbent of ammonia and having a structure in which a heat medium can flow outside the adsorption tubes is cooled by a heat medium. While adsorbing and capturing ammonia by passing a gas containing ammonia through the adsorption tube of the multitubular adsorber, the inside of the adsorption tube is kept at a reduced pressure while heating the multitubular adsorber with a heat medium, and the ammonia is removed. And recovering the ammonia. 2. The method of claim 1, wherein the ammonia adsorbent is a synthetic zeolite,
The method for recovering ammonia according to claim 1, wherein the method is at least one selected from activated carbon, silica gel, alumina, and silica alumina. 3. The method for recovering ammonia according to claim 1, wherein the gas containing ammonia is an exhaust gas from a nitride semiconductor manufacturing process. 4. A multi-tube adsorber having a structure in which a plurality of adsorption tubes filled with an adsorbent of ammonia is built in and a heat medium can be circulated outside the adsorption tubes. While sequentially switching the multitubular adsorber and cooling with a heat medium, ammonia is adsorbed and trapped by passing ammonia-containing gas through the multitubular adsorber, and then the multitubular adsorber is sequentially operated. A method for recovering ammonia, characterized in that the pressure inside the adsorption tube is maintained at a reduced pressure while switching and heating with a heat medium, and ammonia is desorbed and continuously recovered. 5. The method for recovering ammonia according to claim 1, wherein a tube having an inner diameter of 25 to 300 mm and a length of 250 to 3000 mm is used as the adsorption tube. 6. A multitubular adsorber having a structure in which a plurality of adsorption tubes filled with an adsorbent of ammonia are built in and a heat medium can be circulated outside the adsorption tubes. A pump for depressurizing and exhausting the interior of the adsorption tube of the vessel, and adsorbing and capturing ammonia by passing a gas containing ammonia through the adsorption tube while cooling the multitubular adsorber. An ammonia recovery apparatus characterized in that ammonia can be desorbed and recovered while keeping the inside of the adsorption tube under reduced pressure while heating the adsorber with a heat medium. 7. A multi-tubular adsorber having a plurality of adsorbing tubes filled with an ammonia adsorbent and having a structure in which a heat medium can be circulated outside the adsorbing tubes is provided in a plurality of rows in parallel. A pump for depressurizing and exhausting the inside of the adsorption tube of the multitubular adsorber; sequentially switching the multitubular adsorber to cool the multitubular adsorber with a heat medium while adsorbing a gas containing ammonia to the multitubular adsorber; After adsorbing and capturing ammonia by aerating through the tube, the multitubular adsorber is sequentially switched to keep the inside of the adsorption tube at reduced pressure while heating with a heating medium, and ammonia can be continuously removed and desorbed. An ammonia recovery apparatus having a configuration. 8. An adsorption tube having an inner diameter of 25 to 300 mm and a length of 2
The ammonia recovery device according to claim 6 or 7, which is a tube of 50 to 3000 mm.