JPH1157376A - Separation of gaseous mixture by pressure-swing adsorption system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separating method of a gaseous mixture by a pressure- swing adsorption method capable of maintaining the concentration of a product gas and improving the product gas and the supply capacity thereof. SOLUTION: The gaseous mixture separating method by the pressure swing adsorption system using two adsorption vessels 3, 4, and performing an adsorption separating process, a low pressure regenerating process and a pressure restoring process in both adsorption vessels 3, 4 is provided. And the concentration of the final product gas is adjusted by supplying a gas of the same kind as the generated gas in the adsorption separating process and having higher concentration than the generated gas from the outside to the adsorption vessel 3, 4 performing at least one of the pressure restoring process and the low pressure regenerating process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixed gas separation method using a pressure swing adsorption method (PSA method).

[0002]

2. Description of the Related Art Conventionally, nitrogen,
Various methods have been used as a method for separating product gas such as oxygen, but recently, the separation method by the PSA method has been widely used because of the easiness of apparatus design and the low equipment cost. As such a separation method, there is a method of separating oxygen gas and nitrogen gas from raw material air as shown in FIGS. This method uses the original sky blower 41
First, in the first step (see FIG. 9), raw air compressed by the raw air blower 41 is supplied from the inlet end to the left adsorption tank 42 using the pair of adsorption tanks 42 and 43, the receiver tank 44, and the vacuum pump 45. After the nitrogen in the compressed air is mainly adsorbed by the adsorbent in the left adsorption tank 42, oxygen not adsorbed by the adsorbent is extracted from the outlet end as product oxygen gas (about 93% purity) and supplied to the receiver tank 44. (Adsorption separation step). On the other hand, in the right adsorption tank 43,
The inside thereof is evacuated and decompressed by a vacuum pump 45 to desorb nitrogen and the like adsorbed by the adsorbent in the right adsorption tank 43 (decompression regeneration step). Next, in the second step (see FIG. 10), the above-mentioned adsorption separation step is continued in the left adsorption tank 42. On the other hand, in the right adsorption tank 43, a part of the product oxygen gas in the receiver tank 44 is removed from the outlet end by using the negative pressure in the right adsorption tank 43 at the final stage of the above-mentioned reduced pressure regeneration step. (Purge step). Then the third
In the step (see FIG. 11), in the left adsorption tank 42, the above adsorption / separation step is completed, and the inside is evacuated to a reduced pressure by the vacuum pump 45. On the other hand, in the right adsorption tank 43, after the completion of the above-mentioned reduced pressure regeneration step, a part of the product oxygen gas in the receiver tank 44 is supplied from the outlet end to the right adsorption tank 43 while the raw material introduced by the raw air blower 41 is supplied. Air is supplied from the inlet end to the right adsorption tank 43 (pressure recovery step). Then, in the fourth step (see FIG. 12), in the left adsorption tank 42,
The above-mentioned reduced pressure regeneration step is continued. On the other hand, in the right adsorption tank 43, after the completion of the above-mentioned pressure recovery step, the original air blower 41
The raw material air is supplied from the inlet end to the right adsorption tank 43, and the product oxygen gas is extracted from the outlet end. This fourth step is a step corresponding to the above-described first step.
2 and 43 are interchanged. In the fourth and subsequent steps, the same steps as those in the second and third steps (second
And, in the third step, a step in which the operations of both adsorption tanks 42 and 43 are interchanged) is performed. Thus, the first to third
Is repeated to separate oxygen gas and nitrogen gas from the raw material air.

[0003]

However, in the above-mentioned separation method, there is a problem that the concentration of the product oxygen gas frequently decreases due to the ambient environment such as temperature and humidity and the deterioration of the adsorbent. If the product gas is taken out beyond this, there is also a problem that the concentration of the product oxygen gas decreases.
In addition, there is a problem that the concentration of the product oxygen gas is low in principle and cost as compared with other separation methods, and the limit is about 93%.

The present invention has been made in view of such circumstances, and provides a method of separating a mixed gas by a pressure swing adsorption method capable of maintaining the concentration of a product gas, improving the concentration, improving the production capacity, and reducing the cost. For that purpose.

[0005]

In order to achieve the above object, the present invention relates to a mixed gas separation method for separating and generating a product gas from a mixed gas by a pressure swing adsorption method using an adsorption means. A mixed gas separation by a pressure swing adsorption method in which the concentration of a final product gas is adjusted by supplying a gas of the same type and a higher concentration than the generated gas from the outside to at least one of the generated gas extraction paths. The first aspect of the method is to use an adsorption tank containing an adsorbent for selectively adsorbing a specific gas, and perform a mixed gas separation by a pressure swing adsorption method in which an adsorption separation step, a decompression regeneration step, and a pressure recovery step are performed in the adsorption tank. The method
When at least one of the pressure recovery step and the pressure reduction regeneration step is performed in the adsorption tank, the final product gas is supplied from the outside by supplying a gas of the same type as the generated gas generated in the adsorption tank and having a higher concentration than the generated gas. The second aspect is a mixed gas separation method by a pressure swing adsorption method in which the concentration of the gas is adjusted, using an adsorption tank containing an adsorbent for selectively adsorbing a specific gas, and performing an adsorption separation step and a pressure reduction in the adsorption tank. A mixed gas separation method using a pressure swing adsorption method in which a regeneration step and a pressure recovery step are performed, wherein a gas of the same type as the generated gas and a higher concentration than the generated gas is externally mixed into the generated gas generated in the adsorption tank. A third gist of the present invention is a mixed gas separation method using a pressure swing adsorption method in which the concentration of a final product gas is adjusted.

That is, the first mixed gas separation method according to the pressure swing adsorption system of the present invention is the same type as the generated gas, separately from the generated gas separated and generated by using one or more adsorption means. In addition, a gas having a higher concentration than the generated gas is prepared, and the high-concentration gas is supplied to at least one of the adsorbing means and the generated gas taking-out path of the generated gas to be separated and generated using the adsorbing means. . For this reason, the concentration or generation amount of the generated gas is increased by improving the adsorption separation ability of the adsorption means by the high concentration gas, or the concentration of the generation gas is increased by mixing the high concentration gas with the generated gas. be able to. Therefore, even when the concentration of the generated gas is reduced due to the ambient environment such as the temperature and humidity or the deterioration of the adsorbent, the concentration of the generated gas is raised by the high concentration gas to increase the concentration of the product gas to a high concentration. Can be maintained. Also,
In the normal case (when the above-mentioned deterioration etc. has not occurred),
The concentration of the product gas can be improved, or the concentration of the product gas can be maintained to improve the supply capability of the product gas. Therefore, the capability of the apparatus using the first method of the present invention can be designed to be low, and the total cost can be reduced.

In the second method of the present invention, one or more adsorption tanks containing an adsorbent for selectively adsorbing a specific gas are used as the adsorption means. In addition to the generated gas separated and generated using the adsorption tank, a gas of the same type as the generated gas and having a higher concentration than the generated gas is prepared. The high-concentration gas is supplied when performing at least one of the pressure recovery step and the pressure reduction regeneration step among the adsorption separation step, the pressure reduction regeneration step, and the pressure reduction step performed in the adsorption tank. Therefore,
By supplying the high concentration gas to the adsorption tank in accordance with the concentration of the generated gas separated and generated in the adsorption tank, the capacity of the adsorbent in the adsorption tank is increased to increase the concentration of the generated gas or reduce the amount of generation. Can be improved. Therefore, the temperature,
Even when the concentration of the generated gas is reduced due to the ambient environment such as humidity or the deterioration of the adsorbent, the concentration of the product gas can be maintained at a high concentration. In a normal case (when the above-mentioned deterioration does not occur), the production capacity is increased by increasing the concentration of product gas or increasing the amount of gas generated in the adsorption tank while maintaining the concentration. Can be improved. Therefore, the capacity of the apparatus using the second method of the present invention can be designed to be low, and the total cost can be reduced.

According to a third method of the present invention, in the second method, the high-concentration gas is supplied when at least one of the pressure recovery step and the pressure reduction regeneration step is performed in the (one or more) adsorption tanks. Instead, the high-concentration gas is mixed with the generated gas separated and generated in the adsorption tank. Therefore, the concentration of the generated gas can be increased by the high concentration gas. Therefore, even when the concentration of the generated gas is reduced due to the ambient environment such as the temperature and humidity, or the deterioration of the adsorbent, the concentration of the product gas can be maintained at a high concentration. Further, in a normal case (when the above-described deterioration or the like does not occur), the concentration of the product gas can be increased. Further, the capability of supplying the product gas can be improved, the capability of the apparatus using the third method of the present invention can be designed to be low, and the total cost can be reduced. Note that the first method of the present invention is applicable not only to a mixed gas separation method using an adsorption tank, but also to a membrane separation device. In addition, in the present invention, the “reduced pressure regeneration step and the pressure recovery step” include a purge step and a recovery step performed simultaneously in both steps, and a recovery step performed alone between the two steps.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a mixed gas separation apparatus used in the mixed gas separation method of the present invention. In the figure, reference numeral 1 denotes a raw air blower which takes in raw air (atmospheric air) from the outside, compresses the raw air, and sends it to a raw air supply pipe 11.
Reference numerals 3 and 4 denote a pair of left and right adsorption tanks having the same structure. Each of the adsorption tanks 3 and 4 is filled with an adsorbent 6 (zeolite) for nitrogen adsorption. Reference numeral 7 denotes a receiver tank (product oxygen gas storage tank).
The product oxygen gas generated in step 4 is stored. Reference numeral 8 denotes a vacuum pump, which evacuates and depressurizes the insides of both the adsorption tanks 3 and 4. Reference numeral 9 denotes a booster for boosting the product oxygen gas. Reference numeral 10 denotes a high-concentration liquid oxygen storage tank (hereinafter referred to as a storage tank) for storing high-concentration liquid oxygen (concentration 99%) from the outside.

Reference numeral 12 denotes a first introduction pipe having an automatic opening / closing valve 12a for connecting the raw material air supply pipe 11 and an entrance pipe 3c (extending from the entrance end 3a) of the left adsorption tank 3.
Are the feed air supply pipe 11 and the right adsorption tank 4 (the inlet end 4a
Automatic opening / closing valve 1 for connecting an inlet pipe 4c)
It is a 2nd introduction pipe with 3a. Reference numeral 14 denotes a first exhaust pipe with an automatic opening / closing valve 14a for connecting the inlet pipe 3c of the left adsorption tank 3 and the inlet pipe 8a of the vacuum pump 8;
Is a second exhaust pipe with an automatic opening / closing valve 15a connecting the inlet pipe 4c of the right adsorption tank 4 and the inlet pipe 8a of the vacuum pump 8. In the drawing, reference numeral 22 denotes a return pipe with an automatic opening / closing valve 22a for connecting the upstream portion and the downstream portion of the original air blower 1.

Reference numeral 16 denotes a first outlet pipe with an automatic opening / closing valve 16a for connecting an outlet pipe 3d (extending from the outlet end 3b) of the left suction tank 3 and an inlet pipe 7a of the receiver tank 7, and 17 denotes a right suction tank 4 (Extends from the exit end 4b)
Outlet pipe 4d and inlet pipe 7a of receiver tank 7
And a second lead-out pipe with an automatic opening / closing valve 17a. Reference numeral 18 denotes a first connection pipe having an automatic opening / closing valve 18a and a manual flow control valve 18b for connecting an outlet pipe 3d of the left adsorption tank 3 and an outlet pipe 4d of the right adsorption tank 4, and 19 denotes an outlet pipe of the left adsorption tank 3. 3d and outlet pipe 4d of right adsorption tank 4
Open / close valve 19a and manual flow control valve 19b
Attached second connecting pipe. 20 is the receiver tank 7
The upstream and downstream portions of the automatic on-off valve 20 are connected by a bypass pipe 21 with a manual flow control valve 21a. The flow rate setting of the manual flow control valve 21 a of the bypass pipe 21 is set to be smaller than the flow rate setting of the automatic opening / closing valve 20. Reference numeral 23 denotes a product oxygen gas supply pipe for supplying the product oxygen gas in the receiver tank 7 to the demand part, and a booster 9 for increasing the product oxygen gas is provided on the way.

Reference numeral 26 denotes an extraction pipe extending from the storage tank 10, and converts the high-concentration liquid oxygen taken out of the storage tank 10 into an evaporator 2.
The gas is vaporized in 6 a to make high-concentration oxygen gas (concentration 99%), and then depressurized by a pressure reducing valve 26 b and sent to an outlet 27. Reference numeral 28 denotes a backup pipe extending from the outlet 27. When the pressure in the product oxygen gas supply pipe 23 falls below the required pressure, the automatic opening / closing valve 28a opens to open the outlet 2
7 to supply the high-concentration oxygen gas as product oxygen gas to the product oxygen gas supply pipe 23. This allows
The supply of product oxygen gas is not interrupted. In addition, such a backup pipe 28 is
It is used when there is an abnormality in the apparatus or when the capacity is insufficient, and has no function of adjusting the concentration of the product oxygen gas. Reference numeral 30 denotes a high-concentration oxygen gas supply pipe extending from the outlet 27. The high-concentration oxygen gas supply pipe controls the flow rate of the high-concentration oxygen gas in accordance with the concentration of the product oxygen gas by an automatic flow control valve 30a. Reference numeral 31 denotes a first gas supply pipe having an automatic opening / closing valve 31a for connecting the high-concentration oxygen gas supply pipe 30 and the outlet pipe 3d of the left adsorption tank 3; This is a second gas supply pipe with an automatic opening / closing valve 32a that connects the outlet pipe 4d of the tank 4 with it.

Using the above mixed gas separation apparatus, oxygen gas and nitrogen gas can be separated from the raw air in the following manner. That is, in the first step (see FIG. 2),
The automatic opening / closing valves 12a, 15a, 16a, 20 are opened, and the automatic opening / closing valves 13a, 14a, 17a, 18a, 19a, 2
Valves 2a, 31a and 32a are closed. In this state, the raw air taken in by the raw air blower 1 is compressed and sent out to the raw air supply pipe 11, and supplied to the left adsorption tank 3 from the inlet end 3a via the first inlet pipe 12 and the inlet pipe 3c.
In the left adsorption tank 3, after the nitrogen in the raw air is mainly adsorbed by the adsorbent 6, oxygen not adsorbed is extracted from the outlet end 3b as product oxygen gas (purity of about 93%) (adsorption separation step). The product oxygen gas extracted from the outlet end 3b is supplied to the outlet pipe 3d and the first outlet pipe 1
6, supply to the receiver tank 7 via the inlet pipe 7a. On the other hand, the inside of the right adsorption tank 4 is evacuated to a reduced pressure by the vacuum pump 8 through the inlet pipe 4c, the second exhaust pipe 15, and the inlet pipe 8a to desorb nitrogen and the like adsorbed by the adsorbent 6 ( Vacuum regeneration step).

In the second step (see FIG. 3), the above-mentioned adsorption separation step is continued in the left adsorption tank 3. On the other hand, in the right adsorption tank 4, the automatic opening / closing valve 19a is opened at the final stage of the above-mentioned decompression regeneration step, and a part of the product oxygen gas passing through the outlet pipe 3d passes through the second connecting pipe 19 and the outlet pipe 4d. Then, it is supplied to the right adsorption tank 4 from the outlet end 4b. Further, the automatic opening / closing valve 32a is opened to convert the high-concentration liquid oxygen in the storage tank 10 into high-concentration oxygen gas by the evaporator 26a, the outlet 27, the high-concentration oxygen gas supply pipe 30, the second gas supply pipe 32,
The water is supplied from the outlet end 4b to the right adsorption tank 4 via the outlet pipe 4d. By the supply of the product oxygen gas and the high-concentration oxygen gas, desorption of nitrogen from the adsorbent 6 is promoted, and the regeneration of the adsorbent 6 is improved (purge step). In this purging step, supplying the high-concentration oxygen gas to the adsorption tanks 3 and 4 has an effect of increasing the degree of regeneration of the adsorbent 6.

In the third step (see FIG. 4), in the left adsorption tank 3, the automatic opening and closing valves 14a and 22a are opened, the automatic opening and closing valves 12a and 16a are closed, and the raw air blower 1 for the left adsorption tank 3 is opened. The supply of raw material air from the tank is stopped to terminate the above adsorption / separation step, and the inside of the left adsorption tank 3 is evacuated and evacuated by the vacuum pump 8 via the inlet pipe 3c, the first exhaust pipe 14, and the inlet pipe 8a. . On the other hand, in the right adsorption tank 4, the automatic opening / closing valve 18a is opened and the automatic opening / closing valve 15a is opened.
The valves a and 19a are closed, and a gas having a relatively high oxygen concentration remaining at the top of the left adsorption tank 3 (oxygen concentration: 21 to 93%) is utilized using the negative pressure (vacuum pressure) of the right adsorption tank 4. ) Is collected in the right adsorption tank 4 (where the above-mentioned reduced pressure regeneration step has been completed), and the supply of the high-concentration oxygen gas from the storage tank 10 is continued. The automatic opening / closing valve 17a is opened, and the automatic opening / closing valve 20a is opened.
Is closed, and the product oxygen gas in the receiver tank 7 is passed through the inlet pipe 7a, the bypass pipe 21, the second outlet pipe 17, and the outlet pipe 4d using the negative pressure (vacuum pressure) of the right adsorption tank 4. From the outlet end 4b to the right adsorption tank 4 (recovery step). This recovery step is also performed for the purpose of restoring the pressure of the right adsorption tank 4, and can be said to be an initial stage of the restoring step.

In a fourth step (see FIG. 5), the above-described reduced pressure evacuation step is continued in the left adsorption tank 3. On the other hand, in the right adsorption tank 4, the automatic on-off valve 19a is closed, and the collection of the residual gas from the left adsorption tank 3 to the right adsorption tank 4 is completed. At this time, the inside of the right adsorption tank 4 is still under a negative pressure, and in order to restore the pressure to near atmospheric pressure, supply of the product oxygen gas in the receiver tank 7 and the high-concentration oxygen gas from the storage tank 10 are performed. To continue. Further, the automatic opening / closing valve 13a is opened, the automatic opening / closing valve 22a is closed, and the raw air taken in by the raw air blower 1 is passed through the raw air intake pipe 11, the second introducing pipe 13, and the inlet pipe 4c. The liquid is supplied from the inlet end 4a to the right adsorption tank 4 (pressure recovery step).

In the recovery step and the pressure recovery step,
Supplying the high-concentration oxygen gas to the adsorption tanks 3 and 4 depends on the adsorbent 6 regenerated in the pressure reduction regeneration step and the purge step.
This has the effect of more effectively utilizing the adsorption / separation capacity of, and producing a higher concentration or more product oxygen gas in the next adsorption / separation step.

In the fifth step (see FIG. 6), the above-described reduced pressure evacuation step is continued in the left adsorption tank 3. On the other hand, in the right adsorption tank 4, when the pressure recovery step is completed, the automatic on-off valve 2
0 is opened and the automatic on-off valve 32a is closed. That is,
As a whole, the automatic on-off valves 13a, 14a, 17a, 2
0 and the automatic on-off valves 12a, 15a, 16a, 18
a, 19a, 22a, 31a and 32a are closed. In this state, the raw material air sent from the raw air blower 1 is passed through the raw material air intake pipe 11 and the second introduction pipe 13 to the inlet end 4.
a to the right adsorption tank 4 and product oxygen gas is extracted from the outlet end 4b. This fifth step is a step corresponding to the above-mentioned first step, in which the operations of the two adsorption tanks 3 and 4 are interchanged. Then, also in the fifth and subsequent steps, the same steps as the second to fourth steps (in the second to fourth steps, both adsorption tanks 3,
4) is performed. However, the first gas supply pipe 31 is used as a passage for supplying high concentration oxygen gas to the left adsorption tank 3. Thus, the first to fourth
Is repeated to separate oxygen gas and nitrogen gas from the raw material air.

As described above, in this embodiment, the product oxygen gas can be stably separated and generated by the PSA method using the two adsorption tanks 3 and 4. In addition, since the high concentration oxygen gas is supplied from the storage tank 10 to the adsorption tanks 3 and 4 for performing the purge step, the recovery step and the pressure recovery step in the pressure reduction regeneration step, the product oxygen gas generated in the adsorption separation step Concentration can be high, or
The amount of generation can be increased. Therefore, the concentration of the product oxygen gas does not decrease even if the ambient environment such as the temperature and humidity or the adsorbent deteriorates. Further, at the normal time when the above-mentioned deterioration or the like does not occur, the concentration of the product oxygen gas can be improved. Alternatively, it is possible to increase the production amount of the obtained product oxygen gas while maintaining the concentration. Therefore, the capacity of the mixed gas separation device can be designed to be low, and the total cost can be reduced. In addition, storage tank 1 that was previously only used for backup
0 can always be used effectively.

FIG. 7 shows another embodiment of the mixed gas separation apparatus used in the present invention. In this embodiment, a gas supply pipe 30 with an automatic flow control valve 30a extending from an outlet 27 is connected to a product oxygen gas supply pipe 23 in the mixed gas separation apparatus of FIG. Other parts are the same as those of the embodiment shown in FIG. 1, and the same parts are denoted by the same reference numerals. In this embodiment, the effect of improving the capacity of the adsorption tanks 3 and 4 in the embodiment shown in FIG. 1 is not obtained, but the effect of maintaining and improving the concentration of the product oxygen gas or improving the supply capability is exerted.

FIG. 8 shows still another embodiment of the mixed gas separation apparatus used in the present invention. In this embodiment, a gas supply pipe 30 with an automatic flow control valve 30a extending from the outlet 27 is connected to the receiver tank 7 in the mixed gas separation device of FIG. Other parts are the same as those of the embodiment shown in FIG. 7, and the same parts are denoted by the same reference numerals. In this embodiment, the high-concentration oxygen gas in the storage tank 10 is mixed with the generated gas in the receiver tank 7 and is also supplied to both the adsorption tanks 3 and 4 via the receiver tank 7. The same operation and effect as those of the mixed gas separation device shown in FIG.

The separation of the mixed gas targeted by the present invention includes, for example, separation of oxygen and nitrogen gas from air, or specific effective gas (for example, hydrogen, monoxide) from mixed gas during industrial gas production. Concentration and recovery of any effective gas such as carbon and hydrocarbons, purification of gases containing toxic gases, membrane separation, and the like. Examples of the adsorbent used in the present invention include granules such as zeolite, silica gel, activated alumina, and activated carbon.
Used alone or in combination. For example, zeolite is used as a nitrogen adsorbent, carbon is used as an oxygen adsorbent, zeolite is used as a carbon dioxide adsorbent, and the like. For dehumidification, silica gel, activated alumina and the like are preferably used, and for adsorption of hydrocarbons in the air, activated carbon and the like are used. Further, in the above-described embodiments, two adsorption tanks 3 and 4 are used as the mixed gas separation device, but the present invention is not limited to this, and the mixed gas separation device using various pressure swing adsorption methods (for example, One or more adsorption tanks may be used).

[0024]

As described above, according to the first method of the present invention, apart from the generated gas separated and generated by using a plurality of adsorption means, it is of the same type as the generated gas and has a higher concentration than the generated gas. Is prepared, and this high concentration gas is supplied to at least one of the adsorbing means and the generated gas take-out path of the generated gas to be separated and generated using the adsorbing means. For this reason, the concentration or generation amount of the generated gas is increased by improving the adsorption separation ability of the adsorption means by the high concentration gas, or the concentration of the generation gas is increased by mixing the high concentration gas with the generated gas. be able to.
Therefore, even when the concentration of the generated gas is reduced due to the ambient environment such as the temperature and humidity or the deterioration of the adsorbent, the concentration of the generated gas is raised by the high concentration gas to increase the concentration of the product gas to a high concentration. Can be maintained. Further, in a normal case (when the above-described deterioration or the like does not occur), the concentration of the product gas can be improved.
Alternatively, the supply capacity can be improved while maintaining the concentration stably. For this reason, the capability of the apparatus using the first method of the present invention can be designed to be low, and the total cost can be reduced. In addition, the second and third methods of the present invention have the same effect as the first method.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a mixed gas separation device used in the present invention.

FIG. 2 is an explanatory diagram showing the operation of the mixed gas separation device.

FIG. 3 is an explanatory diagram showing an operation of the mixed gas separation device.

FIG. 4 is an explanatory diagram showing the operation of the mixed gas separation device.

FIG. 5 is an explanatory diagram showing the operation of the mixed gas separation device.

FIG. 6 is an explanatory view showing the operation of the mixed gas separation device.

FIG. 7 is a configuration diagram showing another embodiment of the mixed gas separation device used in the present invention.

FIG. 8 is a configuration diagram showing still another embodiment of the mixed gas separation device used in the present invention.

FIG. 9 is an explanatory diagram showing the operation of a conventional example.

FIG. 10 is an explanatory diagram showing the operation of a conventional example.

FIG. 11 is an explanatory diagram showing the operation of a conventional example.

FIG. 12 is an explanatory diagram showing the operation of a conventional example.

[Explanation of symbols]

 3,4 adsorption tank

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Hiromi Otani 2-6-6 Chikushinmachi, Sakai City, Osaka Daido Hokusan Sakai Plant (72) Inventor Yukihiro Hamaki 2-6 Chikushinmachi, Sakai City, Osaka Prefecture 40 Daido Hokusan Co., Ltd. Sakai Plant (72) Inventor Takeharu Shimamoto 2-6 Chikushinmachi, Sakai City, Osaka 40 40 Daido Hokusan Co., Ltd. Sakai Plant (72) Inventor Takahiko Yasuda 2, Chikushinmachi, Sakai City, Osaka Prefecture No. 6 40 Daido Hokusan Co., Ltd. Sakai Plant

Claims (3)

[Claims] 1. A mixed gas separation method for separating and generating a product gas from a mixed gas by a pressure swing adsorption method using an adsorbing means, wherein at least one of the adsorbing means and a generated gas extracting passage is of the same type as the generated gas. A mixed gas separation method using a pressure swing adsorption method, wherein the concentration of the final product gas is adjusted by supplying a gas having a higher concentration than the generated gas from outside. 2. A mixed gas separation method using a pressure swing adsorption method in which an adsorption tank containing an adsorbent for selectively adsorbing a specific gas is used, and an adsorption separation step, a reduced pressure regeneration step, and a pressure recovery step are performed in the adsorption tank. When performing at least one of the pressure recovery step and the pressure reduction regeneration step in the adsorption tank, the final gas is supplied by supplying a gas of the same type as the gas generated in the adsorption tank and having a higher concentration than the generated gas from the outside. A mixed gas separation method using a pressure swing adsorption method, wherein the concentration of a product gas is adjusted. 3. A mixed gas separation method using a pressure swing adsorption method in which an adsorption tank containing an adsorbent for selectively adsorbing a specific gas is used and an adsorption separation step, a reduced pressure regeneration step, and a pressure recovery step are performed in the adsorption tank. The pressure generated by adjusting the concentration of the final product gas by mixing a gas of the same type as the generated gas and having a higher concentration than the generated gas from outside to the generated gas generated in the adsorption tank. A mixed gas separation method using a swing adsorption method.