JP2001137647A - Multistage adsorption treating device for waste gas and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multistage adsorption treating device for waste gas capable of removing components to be removed containing two or more kinds in waste gas with sufficiently high removing efficiency. SOLUTION: The waste gas treating device 100 (multistage adsorption treating device for the waste gas) has single kind adsorption material 90 in which the waste gas 1 is successively circulated and capable of adsorbing organic components 9a and 9b and having different affinity to the organic components 9a and 9b, and adsorption parts 11 and 21 in which the waste gas 1 is brought into contact in counterflow with the adsorption material 90 and the organic components 9a and 9b are adsorbed to the adsorption material 90 in order of higher affinity with the adsorption material 90, a single-step desorption part 12 connected to the adsorption parts 11 and 21 and desorbing the organic components 9a and 9b absorbed to the adsorption material 90 and regenerating the adsorption material 90, and transporting parts 17 and 27 connected to each adsorption part 11 and 21 and the desorption part 12 and returning regenerated adsorption material 90 to each adsorption part 11 and 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for multistage adsorption treatment of exhaust gas, and more particularly, to an exhaust gas containing at least two or more kinds of organic components and other components to be removed from the exhaust gas. And a multistage adsorption treatment apparatus and method.

[0002]

2. Description of the Related Art Conventionally, as a method or an apparatus for removing or recovering a component to be removed from exhaust gas, for example, Japanese Patent Publication No.
No. 8664, JP-A-54-145374, JP-B-63-40772 and the like. These are all methods or apparatuses for bringing exhaust gas into contact with an adsorbent and mainly removing a single type of component to be removed contained in the exhaust gas.

[0003] In many cases, exhaust gas containing two or more types of components to be removed is discharged from equipment or equipment using various solvents, and from the viewpoint of reducing the cost of treating the exhaust gas, these components are removed. There is a keen need for a technology that can remove odor by one device. Also, in recent years, there has been an increasing interest in environmental protection issues, and in order to minimize the amount of released components to the environment, a technology that can remove these components from the exhaust gas with higher removal efficiency has been desired. It is rare. On the other hand, in the above-described conventional method or apparatus, it has been difficult to remove all of two or more types of components to be removed contained in the exhaust gas with a sufficiently high removal efficiency.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of such circumstances, and an object of the present invention is to provide an exhaust gas capable of removing two or more kinds of components to be removed in the exhaust gas with a sufficiently high removal efficiency. It is an object of the present invention to provide a multi-stage adsorption treatment apparatus and method.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventor has conducted intensive studies, and when an exhaust gas containing two types of components to be removed is supplied to a conventional exhaust gas treatment apparatus, one of the components to be removed is removed. Was adsorbed and removed, whereas the other component to be removed was difficult to remove, and it was found that the other component tended to remain mainly in the exhaust gas. As a result of further research by changing the treatment conditions such as the amount of the adsorbent, 1) the adsorbent located on the upstream side of the exhaust gas flow path in the adsorber has two types of components to be removed. (A) The component that is more easily adsorbed is adsorbed more than the component that is hardly adsorbed (B). 2) The adsorbent located on the downstream side adsorbs more component (B) than component (A). I found that The present inventor has further studied based on these findings, and completed the present invention.

That is, in the exhaust gas multi-stage adsorption treatment apparatus of the present invention, exhaust gas containing at least two or more types of components to be removed comes into contact with the adsorbent, and the components to be removed are adsorbed by the adsorbent,
The components to be removed adsorbed on the adsorbent are desorbed and the adsorbent is regenerated, and the regenerated adsorbent is continuously treated with the exhaust gas by coming into contact with the exhaust gas again. It has a single type of adsorbent capable of adsorbing the component to be removed and having a difference in affinity with the component to be removed, and the adsorbent flows down while flowing in a direction opposite to the flow direction of the exhaust gas. The adsorbent and the exhaust gas come into contact with each other, and the components to be removed are adsorbed on the adsorbent in the order of higher affinity with the adsorbent. The adsorbent is transferred from the adsorbent, and a single-stage desorbing section for desorbing the components to be removed adsorbed on the adsorbent and regenerating the adsorbent is connected to each adsorbing section and the desorbing section. And a transport unit for returning to the suction unit. .

In the exhaust gas multi-stage adsorption treatment apparatus having such a configuration, exhaust gas containing at least two or more types of components to be removed comes into contact with a single type of adsorbent while passing sequentially through two or more stages of adsorption sections. The component to be removed is adsorbed on the adsorbent. At this time, in the initial stage when the exhaust gas comes into contact with the adsorbent, even if there is a difference in the ease of adsorption of the component to be adsorbed to the adsorbent, each component to be removed is determined according to the adsorption performance and amount of the adsorbent. Is adsorbed on the adsorbent.

[0008] As the adsorption proceeds, a so-called substitution adsorption occurs in which components that are easily adsorbed (having a high affinity with the adsorbent) are adsorbed in place of components that are hard to be adsorbed (the affinity with the adsorbent is weak). In addition, more components that are easily adsorbed in the adsorbent are adsorbed. That is, displacement adsorption of a component that is easily adsorbed, or conversely, displacement desorption of a component that is hardly adsorbed, occurs. The adsorbent on the most upstream side in the exhaust gas flow direction is
Due to this displacement adsorption phenomenon, components that are easily adsorbed among the components to be removed can be selectively adsorbed.

As described above, the components to be removed are selectively adsorbed on the adsorbent in the order of being easily adsorbed toward the downstream side in the flow direction of the exhaust gas, and are adsorbed on the adsorbent at the most upstream side most easily. Components are mainly adsorbed. Therefore, a plurality of components to be removed in the exhaust gas can be removed from the exhaust gas with high efficiency. In addition, since the adsorbent is brought into contact with the exhaust gas while flowing the adsorbent in the adsorbing section so as to face the flowing direction of the exhaust gas, so-called countercurrent contact between the exhaust gas and the adsorbent is realized, and Since the material can be circulated, continuous processing is possible, and the processing efficiency is improved.

[0010] Furthermore, the suction section is constituted by two stages,
The former adsorbing section of the adsorbing section mainly absorbs the component to be removed having a high affinity with the adsorbent among the components to be removed, and the latter adsorbing section of the adsorbing section has the above affinity. It is preferable that the component to be removed having a lower affinity for the adsorbent than the component to be removed is mainly adsorbed by the adsorbent.

When two types of components to be removed are contained in the exhaust gas, the components to be removed can be sufficiently removed with such a simple configuration. In addition, even if the type of the component to be removed is more, by appropriately adjusting the amount and the circulation amount of the single type of adsorbent, in the former stage, one or more types of components that are relatively easily adsorbed are mainly adsorbed, In the latter stage, the remaining other components can be mainly adsorbed.

Furthermore, it is preferable to use spherical activated carbon as the adsorbent. In this way, the fluidity of the adsorbent is enhanced, and especially when the adsorbent is made into a true spherical shape, the fluidity is further enhanced. In addition, since it is easy to obtain small particles having a uniform particle size as compared with crushed coal or the like, the adsorption speed is increased, and the time to reach the adsorption equilibrium with the component to be removed is reduced.

Further, the method for multi-stage adsorption treatment of exhaust gas of the present invention can be suitably carried out by using the multi-stage adsorption treatment system for exhaust gas according to the present invention. In other words, the exhaust gas multistage adsorption treatment method of the present invention comprises an adsorbing section in which exhaust gas containing at least two or more types of components to be removed comes into contact with the adsorbent and the component to be removed is adsorbed to the adsorbent, and A desorption section for desorbing the components to be removed and regenerating the adsorbent, wherein the regenerated adsorbent again contacts the exhaust gas to continuously treat the exhaust gas. In a multi-stage adsorption treatment method, it is possible to adsorb the component to be removed and to at least two or more adsorption sections having a single type of adsorbent having a difference in affinity with the component to be removed, The components to be removed are adsorbed in descending order of the affinity with the adsorbent by causing the exhaust gas to flow sequentially, and causing the adsorbent to flow down while flowing in such a way as to face the exhaust gas flow direction, thereby bringing the adsorbent into contact with the exhaust gas. Adsorb to the material Transfer the adsorbent from each adsorber to the single-stage desorber, desorb the components removed by the adsorbent, regenerate the adsorbent, and return the regenerated adsorbent to each adsorber Features.

[0014] Furthermore, the suction section is constituted by two stages,
In the adsorption section at the preceding stage of the adsorption section, the component to be removed having a high affinity with the adsorbent among the components to be removed is mainly adsorbed to the adsorbent. It is also preferable that the component to be removed having a low affinity with the adsorbent is mainly adsorbed by the adsorbent. In addition,
It is more preferable to use spherical activated carbon as the adsorbent.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the same components are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a block diagram showing a schematic configuration of a preferred embodiment of an exhaust gas multi-stage adsorption treatment apparatus according to the present invention. As shown in FIG. 1, the exhaust gas treatment device 100 (multi-stage adsorption treatment device for exhaust gas) includes two-stage adsorption units 11 and 21 and a single-stage desorption unit 12. The collection unit 13 is connected.
The adsorption units 11 and 21 and the desorption unit 12 are disposed in a processing tower 110 described later. The suction units 11 and 21 are
The adsorbents 90a and 90b are flowing inside each of them, and the exhaust gas 1 containing two types of organic components 9a9b (components to be removed) is circulated in a direction opposite to the direction in which the adsorbents 90a and 90b flow down. ing. That is, the exhaust gas 1 comes into countercurrent contact with the adsorbents 90a and 90b in the adsorbing sections 11 and 12, and the adsorbents 90a and 90b
The organic components 9a and 9b in the exhaust gas 1 are adsorbed on the exhaust gas.

An adsorbent 90 that has adsorbed the organic components 9a and 9b
a and 90b are both transferred to the desorption section 12 and
The organic components are desorbed and regenerated in 2. Regenerated adsorbents 90a, 90b (hereinafter, regenerated adsorbents 90a, 90b,
A part of the adsorbent 90b is referred to as the “adsorbent 90”), and is returned to the adsorbing unit 11, and the remaining part is returned to the adsorbing unit 21.
Thus, the adsorbents 90a and 90b are circulated between the adsorbing sections 11 and 21 and the desorbing section 12. Then, the exhaust gas 1 that has passed through the adsorption unit 11 becomes a clean gas 10 and is discharged to the outside of the exhaust gas treatment device 100.

Here, the adsorbents 90a and 90b are a single kind of adsorbent capable of adsorbing each organic component and having a difference in affinity with each organic component.
Activated carbon is mentioned as such adsorbents 90a and 90b, and spherical activated carbon is preferable from the viewpoint of exhibiting good fluidity in the adsorbing sections 11 and 21.

FIG. 2 shows an exhaust gas treatment apparatus 100 shown in FIG.
FIG. 3 is a schematic cross-sectional view showing the configuration of FIG. As shown in FIG. 2, the exhaust gas treatment apparatus 100 includes a treatment tower 110 in which a stagnation section 14, a desorption section 12, an adsorption section 11, an adsorption section 21, and an exhaust section 15 are combined. In addition, in the processing tower 110, the respective transport sections 17, 27 of the adsorbents 90a, 90b, and
A recovery section 13 for the organic component 9a connected to the desorption section 12 is provided.

The adsorbing section 11 has a so-called multi-stage fluidized bed configuration, and the multi-stage tray 1 through which the adsorbent 90a flows.
1a. In addition, a flow pipe 16a through which the adsorbent 90a can flow, is provided at a joint between the adsorbing section 11 and the desorbing section 12,
Further, a dispersing section 16b through which the exhaust gas 1 can flow is provided. A blower P1 for supplying the exhaust gas 1 through a pipe 41 is connected to a side wall of the processing tower 110 on a side of the flow pipe 16a.

The desorption section 12 has a heat exchange section 12a composed of a plurality of hollow tubes, and a heat medium is supplied to the outside of the hollow tubes from the heat source 4 through a pipe 44. Also, the detachable part 12
A pipe 45a provided with a blower P5a is connected to the lower end of the pipe, and the carrier gas 5 is supplied into the heat exchange section 12a and into the hollow pipe. A pipe 45c for circulating the carrier gas 5 is provided at the upper end of the desorption section 12.

On the other hand, the adsorbing section 21 disposed in the upper stage of the processing tower 110 has a multi-stage fluidized bed configuration like the adsorbing section 11, and has a multi-stage tray 21a for flowing the adsorbent 90b. are doing. The suction unit 21 and the suction unit 11
A dispersing portion 16c through which the exhaust gas 1 can flow is provided at the connection portion with the above. Further, a pipe 6 for transferring the adsorbent 90b to the desorption section 12 is provided on the lower side wall of the adsorption section 21.
0 is connected, and the adsorbent 90b is transferred to the inside of the desorption section 12 from the flow pipe 60a provided at the upper end of the desorption section 12 through the pipe 60.

The stagnant portion 14 located at the lowermost portion of the processing tower 110 is provided with the adsorbent 9 regenerated by flowing down the desorbing portion 12.
This is for temporarily retaining 0. Adsorbent 90
Part of the pipes 51, 52, 5
3, the transport unit 17 composed of the transporter 3a and the separator 3c
Is returned to the suction unit 11 through Similarly, the adsorbent 90
From the stagnation portion 14, the pipes 61, 62, 6
3, the transport unit 27 including the transport unit 3b and the separator 3d
Is returned to the suction section 21 through Blowers P2a and P2b for supplying the carrier gas 2 of the adsorbent 90 to the carriers 3a and 3b are connected to the carriers 3a and 3b, respectively.

Further, the recovery section 13 connected to the processing tower 110 has a condenser section 7 for condensing the organic components 9a and 9b in the carrier gas 5 sent from the desorption section 12 through the pipe 47a. Organic components 9a, 9b
Is circulated in order to liquefy the liquid. The collection unit 13 has a collection tank 8 for collecting the condensed organic components 9a and 9b. Further, a pipe 47c branched from the pipe 48 is for sending the carrier gas 5 to the desorption section 12. The organic components 9a and 9b collected in the collection tank 8 are discharged to the outside of the exhaust gas treatment device 100 through the pipe 49.

Next, referring to FIG.
An embodiment of the method for multi-stage adsorption treatment of exhaust gas according to the present invention, which employs the process No. 0, will be described. First, two kinds of organic components 9
Exhaust gas 1 containing toluene and 2-propanol as a and 9b, respectively, is introduced into the adsorption section 11 by the blower P1 (hereinafter, the organic components 9a and 9b are referred to as toluene 9a and 2-propanol 9b, respectively). Exhaust gas 1
It moves upward through the dispersion section 16b and through the multi-stage tray 11a constituting the multi-stage fluidized bed. The adsorbent 90a is caused to flow downward from above in the multi-stage tray 11a, and the exhaust gas 1 and the adsorbent 90a are brought into countercurrent contact. In this embodiment, petroleum pitch-based spherical activated carbon is used for both the adsorbents 90a and 90b.

Here, the difficulty of adsorbing the organic component on the adsorbent is generally such that the higher the boiling point, the easier it is to adsorb (the lower the boiling point, the more difficult it is to adsorb). A specific example is a boiling point of 8
Benzene at 0.1 ° C., toluene having a boiling point of 110.6 ° C., and xylene having a boiling point of 144.4 ° C. are easily adsorbed in this order.
Further, the higher the hydrophobicity, the easier the adsorption is (the lower the hydrophobicity, that is, the higher the hydrophilicity, the less the adsorption). Taking alcohol as an example, ethanol, 1-propanol or 2-propanol, and 1-butanol are easily adsorbed in this order. Further, between toluene and 2-propanol, toluene is more easily adsorbed.

The adsorbent 90a in the adsorbing section 11
In the initial stage where the gas and the exhaust gas 1 come into contact, toluene 9a
Although there is a difference in the easiness of the adsorption of 2-propanol 9b and 2-propanol 9b, both are adsorbed together by the adsorbent 90a. Then, when the exhaust gas 1 is continuously supplied to the adsorption section 11, the toluene 9a (a component that is easily adsorbed) in the exhaust gas 1 and the 2-propanol 9b previously adsorbed by the adsorbent 90a
(A component that is hardly adsorbed). That is, displacement adsorption of toluene 9a (conversely, displacement desorption of 2-propanol 9b) occurs.

Therefore, the toluene 9a or 2-
The type and concentration of the organic component such as propanol 9b are determined in advance by sampling analysis and the like, and the circulation amount of the adsorbents 90a and 90b is appropriately adjusted based on the values, so that the exhaust gas 1 Toluene 9
It is possible to selectively adsorb only a on the adsorbent 90a.

When the exhaust gas 1 is continuously supplied while the adsorbent 90a is flowing to the adsorbing section 11, such replacement adsorption occurs constantly in the adsorbing section 11. As a result, the toluene 9a is mainly selectively adsorbed on the adsorbent 90a flowing down to the most upstream side in the flow direction of the exhaust gas 1 in the adsorbing section 11. Note that the adsorbents 90a and 90b indicated by black circles in the figure indicate the adsorbed state, and the white circles indicate the desorbed state.

Next, the exhaust gas 1 from which the toluene 9a has been mainly removed is rectified through the dispersion section 16c,
And is circulated along the multi-stage tray 21a constituting the multi-stage fluidized bed to bring the exhaust gas 1 and the adsorbent 90b into countercurrent contact. Since the exhaust gas 1 mainly contains 2-propanol, displacement adsorption does not occur, and the adsorbent 90b contains 2-propanol.
Propanol 9b can be mainly adsorbed.
The exhaust gas 1 from which the toluene 9a and the 2-propanol 9b have been removed is discharged as a clean gas 10 from the exhaust unit 15 to the outside of the exhaust gas treatment device 100.

On the other hand, the adsorbent 90a mainly adsorbing the toluene 9a in the adsorption section 11 is dropped to the desorption section 12 by its own weight through the flow pipe 16a. On the other hand, the adsorbent 90b mainly adsorbing 2-propanol in the adsorbing section 21 is dropped to the desorbing section 12 by its own weight through the pipe 60 and the flow pipe 60a. Both the adsorbents 90a and 90b gradually move downward (flow down) and reach the heat exchange unit 12a. Steam, oil, or the like, which is a heat medium, is supplied from the heat source 4 to the heat exchange unit 12a, and the temperature in the heat exchange unit 12a is, for example, 150 to 20.
The mixture is heated to 0 ° C. to desorb toluene 9a and 2-propanol from the adsorbents 90a and 90b, respectively. Thus, the adsorbents 90a and 90b are regenerated, cooled by an indirect cooling unit (not shown), and then introduced into the stagnation unit 14. When steam is used as the heat medium, water generated by cooling is discharged to a drain (not shown).

The adsorbent 90 (regenerated adsorbents 90a and 90b) is then transported by the transport unit 17 as follows.
Is returned to the suction unit 11. First, a part of the adsorbent 90 temporarily retained in the retaining section 14 is transferred to the carrier 3a, and the carrier gas 2 such as compressed air is supplied to the carrier 3a by the blower P2a to further the adsorbent 90. Transfer to the separator 3c. At this time, the transfer amount of the adsorbent 90 can be adjusted by the transfer amount adjustment unit of the transfer device 3a. The carrier gas 2 and the adsorbent 90 blown up to the separator 3c are separated by the separator 3c.
, And is returned to the adsorption section 11 and flows again through the multi-stage tray 11a as the adsorbent 90a. On the other hand, the remaining portion of the adsorbent 90 temporarily retained in the retaining section 14 is transferred to the adsorbing section 2 by the transport section 27 in the same manner as the transport section 17 described above.
1 and returned to the multi-stage tray 21 as the adsorbent 90b.
Flow a.

A gas that does not affect the properties of the component to be removed, for example, nitrogen gas, is supplied as a carrier gas 5 to the lower part of the desorption section 12 by the blower P5a. The carrier gas 5 flows through the heat exchange unit 12a and moves upward with the desorbed toluene 9a. This carrier gas 5
Is introduced into the condensing section 7, and the refrigerant 6 such as chiller water and antifreeze is supplied to the condensing section 7 to liquefy the toluene 9a and the 2-propanol 9b, and the liquid is introduced into the collecting tank 8 to be collected. The collected toluene 9a and 2-propanol are discharged from the collection tank 8 to the outside as needed.

The exhaust gas treatment apparatus 10 of the present invention described above
According to the multi-stage adsorption treatment method for exhaust gas and exhaust gas, the single-type adsorbents 90a and 90b are constituted by two stages of adsorbers 11,
Exhaust gas 1 containing toluene 9a and 2-propanol 9b as two kinds of components to be removed.
Are sequentially brought into countercurrent contact with each other. Thus, the toluene 9a and 2
-The propanol 9b can be selectively adsorbed on the adsorbents 90a and 90b. Therefore, the components to be removed such as the toluene 9a and the 2-propanol 9b can be removed from the exhaust gas 1 with a sufficiently high removal efficiency. Therefore, it is possible to obtain a clean gas 10 from which a plurality of components to be removed such as toluene 9a and 2-propanol 9b are sufficiently removed from the exhaust gas 1.

The advanced removal of a plurality of components to be removed from the exhaust gas 1 is achieved by a two-stage adsorption section 1.
Since this is achieved by the detachable unit 12 constituted in one step with the detachable parts 12, 21, it is possible to suppress the complexity and large scale of the device configuration. Moreover, since a single type of adsorbent 90a, 90b is used as the adsorbent, it is possible to prevent a decrease in maintainability and operability. Furthermore, since the adsorbents 90a and 90b are extremely excellent in fluidity, the flow of the adsorbent in the processing tower 110 becomes smooth, and the clogging of the processing tower 110 can be sufficiently prevented. Therefore, stable exhaust gas treatment becomes possible. Further, the adsorbent 90
Since a and 90b flow satisfactorily, the uniformity of contact with the exhaust gas 1 is improved, and the adsorption efficiency can be improved. Furthermore, since the adsorbents 90a and 90b are spherical, the density of the adsorbent in the flow space can be increased, and the adsorbents 90a and 90b generally have an extremely high adsorbing ability. As a result, the size of the device can be reduced.

Although the exhaust gas treatment apparatus 100 has the two-stage adsorption units 11 and 21, it is not limited to the two-stage adsorption units, and the number of components to be removed is three or more. What is necessary is just to provide the adsorption part more than a stage number. Also in this case, the components to be removed that are easily adsorbed can be adsorbed on the adsorbent at the respective adsorbing sections in order. Further, even if the processing apparatus 100 has a two-stage configuration, the suction unit 11 in the preceding stage
This makes it possible to mainly adsorb components that are relatively easily adsorbed, and to adsorb components that are more difficult to be adsorbed in the adsorber 21 in the subsequent stage, and to sufficiently remove these components from the exhaust gas.

Further, the components to be removed are not limited to the above-described organic components, but can be made to correspond to various combinations. Furthermore, although the desorption section 12 and the adsorption sections 11 and 21 are arranged in one processing tower 110, they may be provided separately. For example, the desorption section 12 is different from the adsorption sections 11 and 21. It may be provided in another processing tower. Furthermore, in the desorption section 12, an indirect heating method using a heat medium such as steam or oil is employed, but direct heating such as using both a heat source and a carrier gas with steam may be performed.

Further, the pipe 47 is located at a different position of the attaching / detaching portion 12.
The components to be removed may be recovered by connecting two or more a. Generally, the difficulty of desorbing the adsorbed component from the adsorbent tends to be opposite to the difficulty of adsorbing to the adsorbent. That is, components that are difficult to be adsorbed (weak affinity with the adsorbent) are easily desorbed and easily adsorbed (strong affinity with the adsorbent).
The components are difficult to desorb. As a result, a different concentration distribution may be generated for each component to be removed in the desorption section 12 depending on the affinity of the component to be removed with the adsorbent.

Therefore, if two or more pipes 47a are connected to different positions of the desorption section 12 to collect the components to be removed, the components to be removed can be separated and collected. in this case,
The separability (degree of separation) of the component to be removed tends to depend on the difference in affinity between each component to be removed and the adsorbent. That is, as the plurality of components to be removed have a greater difference in the degree of easiness of being adsorbed to the adsorbent, the separability of each component to be removed is improved.
Therefore, the position where the plurality of pipes 47a for separating and collecting the component to be removed are connected can be optimized according to the type of the component to be removed, the desorption temperature, and the like.

[0040]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

<Example 1> As two kinds of components to be removed,
1000 volppm of toluene and 2-propanol 1
25 ° C, relative humidity (R
H) 40% of the air was continuously supplied to the exhaust gas treatment apparatus 100 having the configuration shown in FIG. The volumetric flow rate of this air is 30
00 m ³ / h (standard condition). Also, the processing tower 110
The tower diameter (outer diameter; the same applies hereinafter) of each of the adsorbing sections 11 and 21 was 1100 mmφ, and the adsorbing sections 11 and 21 were 6 mm each.
A multi-stage fluidized-bed configuration having multi-stage multi-stage trays 11a and 21a was adopted. Petroleum pitch-based spherical activated carbon (manufactured by Kureha Chemical Industry Co., Ltd .; product name: G-BAC) was caused to flow as an adsorbent in these adsorbing sections 11 and 21. The circulation flow rate (mass flow rate) of the spherical activated carbon is 300 kg of the adsorbent 90a in terms of new carbon.
/ H, and the adsorbent 90b was set to 130 kg / h.

Further, the tower diameter of the desorption section 12 is set to 800 mmφ, steam is supplied to the heat exchange section 12a as a heat medium,
Indirect heating was performed. At this time, the desorption temperature was 160 ° C., and nitrogen gas as the carrier gas 5 was circulated at a volume flow rate of 86 m ³ / h (standard state). Further, chiller water having a temperature of 7 ° C. was flowed as the refrigerant 6 into the condensing section 7, and the desorbed components to be removed were cooled and liquefied.

As a result, the outlet of the adsorption unit 11 (the dispersion unit 16
c), the toluene concentration is 5
0 volppm, 2-propanol is 950 volpp
m. At this time, the recovery unit 13
1.82 kg / h, 2-propanol 7.60 kg / h
h and water were collected at a mass flow rate of 3.4 kg / h. The gas concentration at the outlet of the adsorption unit 21 (the position corresponding to the exhaust unit 15) was 40 volppm for toluene and 50 volppm for 2-propanol.

As described above, toluene and 2-propanol in the air were 4% and 5% of the original gas, respectively, and it was confirmed that both were sufficiently removed. From this, according to the exhaust gas multi-stage adsorption treatment apparatus and method of the present invention, from the exhaust gas containing two or more types of components to be removed,
It was confirmed that these components could be removed with a sufficiently high removal efficiency.

<Comparative Example 1> Without supplying spherical activated carbon to the adsorbing section 21 of the exhaust gas treatment apparatus 100, the adsorbing section was replaced with the adsorbing section 11.
Exhaust gas treatment was performed in the same manner as in Example 1 except that the adsorption section 11 was extended upward and the number of multi-stage trays was changed to 12 steps. The total circulation flow rate of the spherical activated carbon used was also the same as in Example 1. The configuration of this apparatus is equivalent to the configuration of a conventional apparatus for treating exhaust gas containing a single type of component to be removed.

As a result, the gas concentration at the outlet of the adsorption section 11 was 50 vol ppm for toluene and 950 vol ppm for 2-propanol, while the recovery section 13 was 11.7 kg / h for toluene and 0.4 kg for 2-propanol. / H, water was collected at a mass flow rate of 1 kg / h. Thus, it was confirmed that 2-propanol (a component that is relatively hard to be adsorbed) could hardly be recovered by the conventional apparatus.

[0047]

As described above, according to the apparatus and method for multistage adsorption treatment of exhaust gas according to the present invention, the exhaust gas containing two or more types of components to be removed is sequentially passed through the adsorption section composed of two or more stages. By doing so, the components to be removed are adsorbed in the order in which the components to be removed are easily adsorbed in each adsorption section. Then, the adsorbent that has adsorbed these components to be removed is regenerated in a desorption section composed of one stage, and the regenerated adsorbent is returned to the adsorber and circulated, whereby two or more types of elements contained in the exhaust gas are removed. The removal components can be continuously removed with a sufficiently high removal efficiency.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a preferred embodiment of a multistage adsorption treatment apparatus for exhaust gas according to the present invention.

FIG. 2 is a schematic sectional view showing a configuration of a preferred embodiment of a multi-stage exhaust gas adsorption treatment apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Exhaust gas, 3a, 3b ... Conveyor, 3c, 3d ... Separator, 7 ... Condensing part, 8 ... Recovery tank, 9a ... Toluene (organic component, component to be removed), 9b ... 2-propanol (organic component, (Removed components), 10: clean gas, 11, 21, adsorption section, 11a, 21a: multi-stage tray, 12: desorption section, 12
a: heat exchange section, 13: recovery section, 17, 27: transport section, 9
0a, 90b: adsorbent, 100: exhaust gas treatment device (multi-stage adsorption treatment device for exhaust gas).

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B01J 8/12 311 B01D 53/34 117A 20/20 20/34 F term (reference) 4D002 AA33 AB03 AC10 BA04 BA13 BA15 CA08 DA41 DA70 EA03 EA08 GA01 GA02 GB01 GB02 GB06 4D012 CA11 CA12 CC07 CC14 CD01 CG01 CH06 CJ04 CK07 4G066 AA05B AA10D CA51 CA56 DA02 DA03 GA01 GA22 GA37 4G070 AA01 AB06 BB21 CA13 CB11 CB19

Claims (6)

[Claims] An exhaust gas containing at least two or more types of components to be removed comes into contact with an adsorbent, the components to be removed are adsorbed by the adsorbent, and the components to be removed adsorbed by the adsorbent are desorbed. The adsorbent is regenerated, and the regenerated adsorbent is brought into contact with the exhaust gas again to continuously treat the exhaust gas. A multi-stage adsorption treatment device for the exhaust gas, wherein the exhaust gas is sequentially circulated and the component to be removed is removed. Has a single type of adsorbent having a difference in affinity with the component to be removed, and the adsorbent flows down while flowing in a direction opposite to the flow direction of the exhaust gas. The adsorbent and the exhaust gas come into contact with each other, and the component to be removed is adsorbed to the adsorbent in order of increasing affinity with the adsorbent; And the adsorbent is transferred from each of the adsorption sections. A single-stage desorbing section for desorbing the component to be removed adsorbed on the adsorbent to regenerate the adsorbent, and being connected to each of the adsorbing sections and the desorbing section, A multistage adsorption treatment apparatus for exhaust gas, comprising: a conveying section that returns the gas to each adsorption section. 2. The adsorbing section is composed of two stages, and the former adsorbing section of the adsorbing section mainly includes the adsorbed component having a high affinity with the adsorbent among the adsorbed components. The adsorbing section at a later stage of the adsorbing section mainly adsorbs a component to be removed having a lower affinity with the adsorbent than the component having a higher affinity to the adsorbent. The exhaust gas multi-stage adsorption treatment apparatus according to claim 1, wherein: 3. The multistage adsorption treatment apparatus for exhaust gas according to claim 1, wherein the adsorbent is spherical activated carbon. 4. An adsorbing section in which exhaust gas containing at least two or more types of components to be removed comes into contact with an adsorbent to adsorb the components to be removed, and the component to be removed adsorbed to the adsorbent. And a desorption section for desorbing the adsorbent to regenerate the adsorbent, wherein the regenerated adsorbent comes into contact with the exhaust gas again to continuously treat the exhaust gas. An adsorption treatment method, wherein at least two or more adsorbing portions capable of adsorbing the component to be removed and having a single type of adsorbent having a difference in affinity with the component to be removed are provided. Flowing the exhaust gas sequentially, and causing the adsorbent to flow down while flowing in a direction opposite to the flow direction of the exhaust gas to bring the adsorbent into contact with the exhaust gas, thereby adsorbing the component to be removed. The adsorbent in order of decreasing affinity with the adsorbent Adsorption allowed, transferring said adsorbent stage of the desorption portion from the each of the adsorption unit,
A method for multistage adsorption treatment of exhaust gas, comprising: desorbing the component to be removed adsorbed on the adsorbent, regenerating the adsorbent, and returning the regenerated adsorbent to each of the adsorption units. 5. The adsorbing section is composed of two stages, and the adsorbent, which has a high affinity with the adsorbent among the components to be removed, is mainly used in the adsorbent at a preceding stage of the adsorbing section. Wherein a component to be removed having a lower affinity to the adsorbent than the component to be removed having a higher affinity is mainly adsorbed to the adsorbent in the latter one of the adsorbers. Item 5. The method for multistage adsorption treatment of exhaust gas according to Item 4. 6. The multistage adsorption treatment method for exhaust gas according to claim 4, wherein spherical activated carbon is used as the adsorbent.