JP4317304B2 - Apparatus and method for multistage adsorption treatment of exhaust gas - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to an exhaust gas multistage adsorption treatment apparatus and method, and more particularly, an exhaust gas multistage adsorption treatment apparatus and method that removes the components to be removed from exhaust gas containing at least two kinds of components to be removed such as organic components. About.
[0002]
[Prior art]
Conventionally, methods or apparatuses for removing or recovering components to be removed from exhaust gas have been described in, for example, Japanese Patent Publication No. 53-8664, Japanese Patent Publication No. 54-145374, Japanese Patent Publication No. 63-40772, and the like. Things. These are methods or devices that mainly remove a single type of component to be removed contained in the exhaust gas by bringing the exhaust gas into contact with the adsorbent.
[0003]
By the way, there are many cases where exhaust gas containing two or more kinds of components to be removed is discharged from facilities and equipment using various solvents, and from the viewpoint of reducing the treatment cost of exhaust gas, these components to be removed are one. A technology that can be removed by the apparatus is eagerly desired. In recent years, interest in environmental conservation issues has increased, and a technology that can remove these components to be removed from exhaust gas with higher removal efficiency is desired in order to reduce the amount of components to be removed to the environment as much as possible. It is rare. On the other hand, in the conventional method or apparatus, it has been difficult to remove all of the two or more kinds of components to be removed contained in the exhaust gas with sufficiently high removal efficiency.
[0004]
[Problems to be solved by the invention]
Therefore, the present invention has been made in view of such circumstances, and provides an exhaust gas multistage adsorption treatment apparatus and method that can remove two or more kinds of components to be removed contained in the exhaust gas with sufficiently high removal efficiency. For the purpose.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present inventor repeated earnest research, and when an exhaust gas containing two kinds of components to be removed is supplied to a conventional exhaust gas treatment apparatus, one of the components to be removed is adsorbed and removed. It has been found that the other component to be removed is difficult to remove and the other component tends to remain mainly in the exhaust gas. And as a result of further research by varying the processing conditions such as the amount of adsorbent,
1) On the adsorbent located upstream of the exhaust gas flow path in the adsorption section, (A) the more easily adsorbed component of the two types of components to be removed is adsorbed more than (B) the component that is difficult to adsorb. ,
2) It was found that the adsorbent located on the downstream side adsorbs more component (B) than component (A).
And this inventor further advanced research based on these knowledge, and came to complete this invention.
[0006]
That is, the exhaust gas multistage adsorption treatment apparatus of the present invention is configured such that exhaust gas containing at least two kinds of components to be removed comes into contact with the adsorbent, the components to be removed are adsorbed on the adsorbent, and the components to be removed adsorbed on the adsorbent. Is desorbed and the adsorbent is regenerated, and the regenerated adsorbent is in contact with the exhaust gas again to continuously treat the exhaust gas. The exhaust gas is sequentially circulated and can adsorb the components to be removed. And has a single type of adsorbent that has a difference in affinity with the component to be removed, and the adsorbent and the exhaust gas come into contact with each other as the adsorbent flows while facing the flow direction of the exhaust gas. And at least two or more stages of adsorbing parts that are adsorbed by the adsorbing material in descending order of affinity with the adsorbing material, and the adsorbing material is transferred from each adsorbing part to be adsorbed. Desorbed components removed by adsorption And one stage of desorption unit for reproducing the adsorbent Te is connected to the suction unit and desorption unit, characterized in that it comprises a conveying unit for returning the regenerated adsorbent to the adsorption unit.
[0007]
In the multi-stage adsorption treatment apparatus for exhaust gas having such a configuration, the exhaust gas containing at least two kinds of components to be removed comes into contact with a single kind of adsorbent while sequentially passing through the adsorption section of two or more stages to be removed. Components are adsorbed on the adsorbent. At this time, even if there is a difference in the ease with which the components to be removed are adsorbed at the initial stage when the exhaust gas comes into contact with the adsorbent, each component to be removed depends on the adsorption performance and amount of the adsorbent. Is adsorbed by the adsorbent.
[0008]
As adsorption progresses, so-called substitutional adsorption occurs in which components that are easily adsorbed (strong affinity with the adsorbent) are replaced with components that are difficult to adsorb (low affinity with the adsorbent) and are adsorbed. More components that are easily adsorbed inside are adsorbed. That is, substitution adsorption of components that are easily adsorbed, or conversely, substitution desorption of components that are difficult to adsorb occurs. The adsorbent on the most upstream side in the exhaust gas flow direction can selectively adsorb components that are easily adsorbed among the components to be removed by this substitution adsorption phenomenon.
[0009]
In this way, the components to be removed are selectively adsorbed to the adsorbent in the order in which they are easily adsorbed toward the downstream side in the exhaust gas flow direction, and the adsorbent on the most upstream side mainly contains the components that are most likely to be adsorbed. Adsorbed. Therefore, a plurality of components to be removed in the exhaust gas can be removed from the exhaust gas with high efficiency. Further, since the adsorbent and the exhaust gas are brought into contact with each other while the adsorbent is caused to flow in the adsorption portion so as to face the direction in which the exhaust gas flows, so-called countercurrent contact between the exhaust gas and the adsorbent is realized and the adsorption is performed. Since the material can be circulated, continuous processing is possible and processing efficiency is improved.
[0010]
Furthermore, the adsorption part is composed of two stages, and the adsorption part in the previous stage among the adsorption parts is one in which the to-be-removed component having a high affinity with the adsorbent among the to-be-removed components is mainly adsorbed to the adsorbent. Of the adsorbing parts, the latter adsorbing part is preferably such that the to-be-removed component having a lower affinity with the adsorbing material is mainly adsorbed to the adsorbing material than the to-be-removed component having a high affinity.
[0011]
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 there are more types of components to be removed, by adjusting the amount of single-type adsorbent, circulation amount, etc. as appropriate, in the previous stage, one or more types of components that are relatively easily adsorbed are adsorbed, In the latter stage, the remaining other components can be mainly adsorbed.
[0012]
Furthermore, it is preferable to use spherical activated carbon as the adsorbent. In this way, the fluidity of the adsorbent can be improved, and the fluidity can be further enhanced if it is particularly spherical. Moreover, since it is easy to make it the thing of the small particle size in which the particle size was equal compared with crushed charcoal etc., the adsorption speed is raised and the time to reach adsorption equilibrium with a to-be-removed component is shortened.
[0013]
Further, the exhaust gas multistage adsorption treatment method of the present invention can be suitably carried out using the exhaust gas multistage adsorption treatment apparatus according to the present invention. That is, the multistage adsorption treatment method for exhaust gas according to the present invention includes an adsorption part in which exhaust gas containing at least two kinds of components to be removed comes into contact with the adsorbent, and the components to be removed are adsorbed on the adsorbent, and adsorbed on the adsorbent. And a desorption part that regenerates the adsorbent by desorbing the components to be removed, and the exhaust gas that has been continuously processed is processed by contacting the regenerated adsorbent with the exhaust gas again. In a multi-stage adsorption treatment method, it is possible to adsorb a component to be removed, and at least two or more stages of adsorption parts having a single kind of adsorbent having a difference in affinity with the component to be removed. Adsorbing the components to be removed in descending order of affinity with the adsorbent by flowing the exhaust gas in sequence and flowing down the adsorbent while facing the flow direction of the exhaust gas and bringing the adsorbent into contact with the exhaust gas Adsorb to the material Therefore, the adsorbent is transferred from each adsorbing section to the one-stage desorbing section, the to-be-removed components adsorbed on the adsorbent are desorbed to regenerate the adsorbent, and the regenerated adsorbent is returned to each adsorbing section. Features.
[0014]
Furthermore, the adsorption part is composed of two stages. Among the adsorption parts, the removal part having a high affinity with the adsorption material is mainly adsorbed to the adsorption material, and the adsorption part is mainly adsorbed. It is preferable to adsorb mainly a component to be removed, which has a lower affinity with the adsorbent than a component to be removed with a higher affinity, in the adsorbing part in the subsequent stage. Furthermore, it is more preferable to use spherical activated carbon as the adsorbent.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.
[0016]
FIG. 1 is a block diagram showing a schematic configuration of a preferred embodiment of an exhaust gas multistage adsorption treatment apparatus according to the present invention. As shown in FIG. 1, the exhaust gas treatment apparatus 100 (exhaust gas multistage adsorption treatment apparatus) includes adsorption sections 11 and 21 configured in two stages and a desorption section 12 configured in one stage. The collection unit 13 is connected. These adsorption parts 11 and 21 and desorption part 12 are arranged in processing tower 110 mentioned below. The adsorbing parts 11 and 21 have adsorbents 90a and 90b flowing inside, and two kinds of organic components 9a9b (components to be removed) are arranged in a direction opposite to the direction in which the adsorbents 90a and 90b flow and flow down. Exhaust gas 1 containing is circulated. That is, the exhaust gas 1 comes into countercurrent contact with the adsorbents 90a and 90b in the adsorbing portions 11 and 12, and the organic components 9a and 9b in the exhaust gas 1 are adsorbed by the adsorbents 90a and 90b.
[0017]
The adsorbents 90a and 90b that have adsorbed the organic components 9a and 9b are both transferred to the desorption unit 12, and the organic components are desorbed and regenerated in the desorption unit 12. Part of the regenerated adsorbents 90 a and 90 b (hereinafter, the regenerated adsorbents 90 a and 90 b are collectively referred to as “adsorbent 90”) is returned to the adsorbing unit 11, and the rest is returned to the adsorbing unit 21. . In this way, the adsorbents 90a and 90b are circulated between the adsorbing units 11 and 21 and the desorbing unit 12. And the exhaust gas 1 which passed the adsorption | suction part 11 turns into the clean gas 10, and is discharged | emitted outside the exhaust gas processing apparatus 100. FIG.
[0018]
Here, the adsorbents 90a and 90b are capable of adsorbing each organic component, and are a single kind of adsorbent having a difference in affinity with each organic component. Examples of such adsorbents 90a and 90b include activated carbon, and spherical activated carbon is preferable from the viewpoint of exhibiting good fluidity in the adsorbing portions 11 and 21.
[0019]
FIG. 2 is a schematic cross-sectional view showing the configuration of the exhaust gas treatment apparatus 100 shown in FIG. As shown in FIG. 2, the exhaust gas treatment apparatus 100 includes a treatment tower 110 in which a staying part 14, a desorption part 12, an adsorption part 11, an adsorption part 21, and an exhaust part 15 are combined. Further, the processing tower 110 is provided with the respective conveying parts 17 and 27 of the adsorbents 90a and 90b and the recovery part 13 of the organic component 9a connected to the desorption part 12.
[0020]
The adsorption unit 11 has a so-called multistage fluidized bed type configuration, and includes a multistage tray 11a through which the adsorbent 90a flows. In addition, a connecting pipe between the adsorbing part 11 and the desorbing part 12 is provided with a flow pipe 16a through which the adsorbent 90a can flow and a dispersion part 16b through which the exhaust gas 1 can flow. A blower P1 for supplying the exhaust gas 1 through the pipe 41 is connected to the side wall of the processing tower 110 on the side of the flow pipe 16a.
[0021]
The desorption part 12 has a heat exchange part 12a composed of a plurality of hollow tubes, and a heat medium is supplied from the heat source 4 through the pipe 44 to the outside of the hollow tubes. A pipe 45a provided with a blower P5a is connected to the lower end of the detachable part 12, so that the carrier gas 5 is supplied into the heat exchange part 12a and inside the hollow tube. . A pipe 45 c for circulating the carrier gas 5 is provided at the upper end of the detachable part 12.
[0022]
On the other hand, the adsorption part 21 arranged on the upper stage of the processing tower 110 has a multi-stage fluidized bed type configuration like the adsorption part 11, and has a multi-stage tray 21a for flowing the adsorbent 90b. . Moreover, the dispersion | distribution part 16c which can distribute | circulate the waste gas 1 is provided in the coupling | bond part of the adsorption | suction part 21 and the adsorption | suction part 11. FIG. Further, a pipe 60 for transferring the adsorbent 90 b to the desorption part 12 is connected to the lower end side wall of the adsorption part 21, and the adsorbent 90 b is provided at the upper end part of the desorption part 12 through the pipe 60. It is transferred from the flow pipe 60a to the inside of the detachable part 12.
[0023]
Moreover, the retention part 14 located in the lowermost part of the processing tower 110 is for temporarily retaining the adsorbent 90 regenerated by flowing down the desorption part 12. A part of the adsorbent 90 is returned to the adsorbing unit 11 from the staying unit 14 through the conveying unit 17 constituted by the pipes 51, 52, 53, the conveying device 3a and the separator 3c. Similarly, the remaining part of the adsorbent 90 is returned from the staying part 14 to the adsorbing part 21 through the conveying part 27 composed of the pipes 61, 62, 63, the conveying device 3b and the separator 3d. Blowers P2a and P2b for supplying the transport gas 2 of the adsorbent 90 to the transporters 3a and 3b are connected to the transporters 3a and 3b, respectively.
[0024]
Further, the recovery unit 13 connected to the processing tower 110 has a condensing unit 7 that condenses the organic components 9a and 9b in the carrier gas 5 fed from the desorption unit 12 through the pipe 47a. A refrigerant 6 is passed through the condensing unit 7 in order to liquefy the organic components 9a and 9b. Moreover, the collection | recovery part 13 has the collection tank 8 for collect | recovering the condensed organic components 9a and 9b. Further, a pipe 47 c branched from the pipe 48 is for supplying the carrier gas 5 to the desorption part 12. The organic components 9a and 9b recovered in the recovery tank 8 are discharged to the outside of the exhaust gas treatment apparatus 100 through the pipe 49.
[0025]
Next, an embodiment of the multistage adsorption treatment method for exhaust gas according to the present invention using the exhaust gas treatment apparatus 100 will be described with reference to FIG. First, exhaust gas 1 containing toluene and 2-propanol as the two kinds of organic components 9a and 9b is introduced into the adsorption section 11 by the blower P1 (hereinafter, the organic components 9a and 9b are respectively toluene 9a and 2-propanol 9b and Write down). The exhaust gas 1 moves upward through the dispersion part 16b and through the multistage tray 11a constituting the multistage fluidized bed. The adsorbent 90a flows from the upper side to the lower side of the multi-stage tray 11a, and the exhaust gas 1 and the adsorbent 90a are brought into countercurrent contact. In the present embodiment, both the adsorbents 90a and 90b use petroleum pitch-based spherical activated carbon.
[0026]
Here, the difficulty of adsorbing the organic component to the adsorbent is generally more easily adsorbed as the boiling point is higher (the lower the boiling point is, the less likely it is to be adsorbed). As a specific example, benzene having a boiling point of 80.1 ° 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. Also, the higher the hydrophobicity, the easier it is to adsorb (the lower the hydrophobicity, that is, the higher the hydrophilicity, the harder it is to adsorb). Taking alcohol as an example, ethanol, 1-propanol or 2-propanol, and 1-butanol are easily adsorbed in this order. In addition, toluene and 2-propanol are more easily adsorbed.
[0027]
At the initial stage where the adsorbent 90a and the exhaust gas 1 are in contact with each other in the adsorbing section 11, there is a difference in the ease of adsorption of toluene 9a and 2-propanol 9b, but both are adsorbed on the adsorbent 90a. Go. When the exhaust gas 1 is continuously supplied to the adsorption unit 11, toluene 9a (a component that is easily adsorbed) in the exhaust gas 1 and 2-propanol 9b (a component that is difficult to be adsorbed) previously adsorbed on the adsorbent 90a Replacement occurs. That is, substitutional adsorption of toluene 9a (in other words, substitutional desorption of 2-propanol 9b) occurs.
[0028]
Therefore, the kind and concentration of organic components such as toluene 9a and 2-propanol 9b in the exhaust gas 1 are obtained in advance by sampling analysis or the like, and the circulation amount and the like of the adsorbents 90a and 90b are appropriately adjusted based on this value. Thus, only the toluene 9a in the exhaust gas 1 can be selectively adsorbed on the adsorbent 90a in the adsorption unit 11.
[0029]
When the exhaust gas 1 is continuously supplied while causing the adsorbent 90 a to flow to the adsorption unit 11, such substitutional adsorption is steadily generated in the adsorption unit 11. As a result, 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 portion 11. In the figure, adsorbents 90a and 90b indicated by black circles indicate an adsorbed state, and white circles indicate a desorbed state.
[0030]
Next, the exhaust gas 1 from which the toluene 9a is mainly removed is rectified through the dispersion part 16c, introduced into the adsorption part 21, and circulated along the multistage tray 21a constituting the multistage fluidized bed, and the exhaust gas 1 and the adsorbent 90b In countercurrent contact. Since the exhaust gas 1 mainly contains 2-propanol, substitutional adsorption does not occur, and the adsorbent 90b can mainly adsorb 2-propanol 9b. The exhaust gas 1 from which the toluene 9a and 2-propanol 9b have been removed is discharged as clean gas 10 from the exhaust unit 15 to the outside of the exhaust gas treatment apparatus 100.
[0031]
On the other hand, the adsorbent 90a mainly adsorbing toluene 9a in the adsorbing unit 11 is dropped to the desorbing unit 12 by its own weight through the flow pipe 16a. On the other hand, the adsorbent 90b mainly adsorbing 2-propanol by the adsorbing unit 21 is dropped to the desorbing unit 12 by its own weight through the pipe 60 and the flow pipe 60a. Both adsorbents 90a and 90b gradually move downward (downflow) and reach the heat exchange section 12a. Steam or oil, which is a heat medium, is supplied from the heat source 4 to the heat exchange unit 12a, and is heated so that the temperature in the heat exchange unit 12a is, for example, 150 to 200 ° C. From the adsorbents 90a and 90b Toluene 9a and 2-propanol are desorbed respectively. As a result, the adsorbents 90 a and 90 b are regenerated, cooled by an indirect cooling unit (not shown), and then introduced into the staying unit 14. In addition, when steam is used as the heat medium, water generated by the cooling is discharged to a drain (not shown).
[0032]
Then, a part of the adsorbent 90 (regenerated adsorbents 90a and 90b) is returned to the adsorber 11 by the transport unit 17 as follows. First, a part of the adsorbent 90 temporarily retained in the retention section 14 is transferred to the transporter 3a, and the transporter gas 2 such as compressed air is supplied to the transporter 3a by the blower P2a to further increase the adsorbent 90. Transfer to separator 3c. At this time, the transfer amount of the adsorbent 90 can be adjusted by the transfer amount adjusting unit of the transporter 3a. The carrier gas 2 and the adsorbent 90 blown up to the separator 3c are stalled by the separator 3c, returned to the adsorbing unit 11, and flow through the multi-stage tray 11a again as the adsorbent 90a. On the other hand, in the same manner as that by the transport unit 17 described above, the remaining portion of the adsorbent 90 temporarily retained in the retention unit 14 is returned to the adsorber 21 by the transport unit 27 and is again used as the adsorbent 90b. To flow.
[0033]
Further, the blower P5a supplies a gas that does not affect the physical properties of the component to be removed, for example, nitrogen gas, as the carrier gas 5 to the lower part of the desorption part 12. The carrier gas 5 flows through the heat exchange unit 12a, and moves upward with the desorbed toluene 9a. The carrier gas 5 is introduced into the condensing unit 7, and a refrigerant 6 such as chiller water or antifreeze is supplied to the condensing unit 7 to liquefy the toluene 9 a and 2-propanol 9 b, and is introduced into the collection tank 8 and collected. The recovered toluene 9a and 2-propanol are discharged from the recovery tank 8 to the outside as necessary.
[0034]
According to the exhaust gas treatment apparatus 100 and the exhaust gas multistage adsorption treatment method of the present invention described above, a single kind of adsorbents 90a and 90b are caused to flow to the adsorbing sections 11 and 21 configured in two stages, respectively. Countercurrent contact is sequentially made with exhaust gas 1 containing toluene 9a and 2-propanol 9b as components to be removed. Thereby, toluene 9a and 2-propanol 9b can be selectively made to adsorb | suck to adsorption material 90a, 90b in each adsorption part 11 and 21 using substitution adsorption. Therefore, these to-be-removed components such as toluene 9a and 2-propanol 9b can be removed from the exhaust gas 1 with 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.
[0035]
Further, such a high degree of removal of a plurality of components to be removed from the exhaust gas 1 is achieved by the adsorption sections 11 and 21 configured in two stages and the desorption section 12 configured in one stage. Complexity and enlargement can be suppressed. In addition, since a single type of adsorbent 90a, 90b is used as the adsorbent, it is possible to prevent deterioration in maintainability and operability. Furthermore, since the adsorbents 90a and 90b are extremely excellent in fluidity, the adsorbent in the processing tower 110 flows smoothly, and blockage of the processing tower 110 can be sufficiently prevented. Therefore, stable exhaust gas treatment becomes possible. Furthermore, since the adsorbents 90a and 90b flow favorably, the uniformity of contact with the exhaust gas 1 can be 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 generally the adsorbent performance of the exhaust gas treatment apparatus 100 is enhanced because the adsorbent 90a, 90b has an extremely high adsorbability. As a result, the apparatus can be miniaturized.
[0036]
The exhaust gas treatment apparatus 100 includes the adsorption sections 11 and 21 having a two-stage configuration, but is not limited to two stages. If there are three or more kinds of components to be removed, the number of stages or more according to the number of the components to be removed. What is necessary is just to provide an adsorption | suction part. Also in this case, it is possible to cause the adsorbent to adsorb in order from the component to be removed that is easily adsorbed. Further, even in a two-stage configuration like the processing apparatus 100, a component that is relatively easily adsorbed by the front-stage adsorption unit 11 is mainly adsorbed, and a component that is less easily adsorbed by the rear-stage adsorption unit 21 is mainly adsorbed. This makes it possible to sufficiently remove these components to be removed from the exhaust gas.
[0037]
Furthermore, the components to be removed are not limited to the organic components described above, and can be made to correspond to various combinations. Furthermore, although the desorption part 12 and the adsorption parts 11 and 21 are arranged in one processing tower 110, these may be provided separately. For example, the desorption part 12 is different from the adsorption parts 11 and 21. You may provide in another processing tower. Furthermore, although the desorption part 12 employs an indirect heating method using a heat medium such as steam or oil, direct heating may be performed such that steam serves as both a heat source and a carrier gas.
[0038]
In addition, two or more pipes 47a may be connected to different positions of the desorption part 12 to collect the components to be removed. In general, the difficulty of desorbing the adsorbed components to be removed from the adsorbent tends to be opposite to the difficulty of adsorption to the adsorbent. That is, components that are difficult to be adsorbed (weak affinity with the adsorbent) are easily desorbed, and components that are easily adsorbed (strong affinity with the adsorbent) are difficult to desorb. As a result, different concentration distributions can be generated for each component to be removed, depending on the affinity of the component to be removed with the adsorbent.
[0039]
Therefore, if two or more pipes 47a are connected to different predetermined positions of the desorption part 12 and the components to be removed are collected, the components to be removed can be collected separately. In this case, the separability (degree of separation) of the components to be removed tends to depend on the difference in affinity between each component to be removed and the adsorbent. That is, the separation property of each component to be removed increases as the plurality of components to be removed has a larger difference in the degree of ease of adsorption to the adsorbent. Therefore, the position where the plurality of pipes 47a for separating and collecting the components to be removed can be optimized according to the types of these components to be removed, the desorption temperature, and the like.
[0040]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.
[0041]
<Example 1>
As two types of components to be removed, air containing 1000 volppm of toluene and 1000 volppm of 2-propanol at a temperature of 25 ° C. and a relative humidity (RH) of 40% was continuously supplied to the exhaust gas treatment apparatus 100 having the configuration shown in FIG. The volume flow of this air is 3000m ^Three / H (standard state). Further, the tower diameter (outer diameter; the same applies hereinafter) of the treatment tower 110 is 1100 mmφ for both the adsorption sections 11 and 21, and the adsorption sections 11 and 21 are configured in a multistage fluidized bed type having six multistage trays 11 a and 21 a, respectively. It was. Petroleum pitch-based spherical activated carbon (manufactured by Kureha Chemical Industry Co., Ltd .; product name G-BAC) was allowed to flow through these adsorbing portions 11 and 21 as adsorbents. The circulation flow rate (mass flow rate) of the spherical activated carbon was 300 kg / h for the adsorbent 90a and 130 kg / h for the adsorbent 90b in terms of fresh coal.
[0042]
Moreover, the tower diameter of the desorption part 12 was 800 mmφ, steam was supplied to the heat exchange part 12 a as a heat medium, and indirect heating was performed. The desorption temperature at this time is 160 ° C., and nitrogen gas is 86 m as the carrier gas 5. ^Three Circulation was performed at a volume flow rate of / h (standard state). Further, chiller water having a temperature of 7 ° C. was flowed to the condensing unit 7 as the refrigerant 6, and the desorbed components to be removed were cooled and liquefied.
[0043]
As a result, the gas concentration at the outlet of the adsorption unit 11 (the position corresponding to the dispersion unit 16c) was 50 volppm for toluene and 950 volppm for 2-propanol. At this time, the recovery unit 13 recovered toluene at a mass flow rate of 11.82 kg / h, 2-propanol at 7.60 kg / h, and water at 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.
[0044]
Thus, toluene and 2-propanol in the air were 4% and 5% of the respective raw gases, and it was confirmed that both were sufficiently removed. From this, it was confirmed that according to the exhaust gas multistage adsorption treatment apparatus and method of the present invention, these components can be removed with sufficiently high removal efficiency from exhaust gas containing two or more kinds of components to be removed.
[0045]
<Comparative example 1>
Except that the spherical activated carbon is not supplied to the adsorption unit 21 of the exhaust gas treatment apparatus 100, the adsorption unit is configured only by the adsorption unit 11, and the adsorption unit 11 is extended upward to form a multistage tray with 12 stages. Exhaust gas treatment was performed in the same manner as in Example 1. The total circulation flow rate of the spherical activated carbon used was also the same as in Example 1. In addition, this apparatus structure is equivalent to the structure of the apparatus for processing the waste gas containing the conventional single type of to-be-removed component.
[0046]
As a result, the gas concentrations at the outlet of the adsorption unit 11 are 50 volppm for toluene and 950 volppm for 2-propanol, while in the recovery unit 13, 11.7 kg / h for toluene and 0.4 kg / h for 2-propanol, Water was recovered at a mass flow rate of 1 kg / h. Thus, it was confirmed that 2-propanol (a component that is relatively difficult to adsorb) can hardly be recovered with the conventional apparatus.
[0047]
【The invention's effect】
As described above, according to the exhaust gas multistage adsorption treatment apparatus and method according to the present invention, each of the exhaust gas containing two or more kinds of components to be removed is sequentially circulated in an adsorption section composed of two or more stages. The to-be-removed components are adsorbed in the adsorbing portion in the order in which they are easily adsorbed. Then, the adsorbent that adsorbs these components to be removed is regenerated in a desorption section configured in a single stage, and the regenerated adsorbent is returned to the adsorption section and circulated, so that two or more kinds of adsorbent contained in the exhaust gas are contained. The removal component can be removed continuously with sufficiently high removal efficiency.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the configuration of a preferred embodiment of an exhaust gas multistage adsorption treatment apparatus according to the present invention.
FIG. 2 is a schematic cross-sectional view showing the configuration of a preferred embodiment of an exhaust gas multi-stage 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, to-be-removed component), 9b ... 2-propanol (Organic component, to-be-covered) Removal component), 10 ... clean gas, 11, 21 ... adsorption part, 11a, 21a ... multi-stage tray, 12 ... desorption part, 12a ... heat exchange part, 13 ... recovery part, 17, 27 ... conveyance part, 90a, 90b ... Adsorbent, 100 ... exhaust gas treatment device (exhaust gas multi-stage adsorption treatment device).

Claims (6)

Exhaust gas containing at least two types of components to be removed comes into contact with the adsorbent, the components to be removed are adsorbed on the adsorbent, and the components to be removed adsorbed on the adsorbent are desorbed to regenerate the adsorbent. And the regenerated adsorbent is again in contact with the exhaust gas, whereby the exhaust gas is continuously processed by the exhaust gas multi-stage adsorption treatment apparatus,
The exhaust gas is sequentially circulated, and 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. At least two or more stages where the adsorbent and the exhaust gas come into contact with each other while flowing so as to oppose the flow direction, and the components to be removed are adsorbed by the adsorbent in descending order of affinity with the adsorbent. Adsorbing part of
A first-stage desorption unit that is connected to each of the adsorption units, transfers the adsorbent from each of the adsorption units, desorbs the component to be removed adsorbed on the adsorbent, and regenerates the adsorbent;
A transport unit connected to each of the adsorption units and the desorption unit, and returning the regenerated adsorbent to each of the adsorption units;
A multi-stage adsorption treatment apparatus for exhaust gas, comprising: The adsorption part is composed of two stages,
Of the adsorbing part, the former adsorbing part is one in which the to-be-removed component having a high affinity with the adsorbing material among the to-be-removed components is mainly adsorbed to the adsorbing material,
Of the adsorbing parts, the latter adsorbing part is one in which a to-be-removed component having a lower affinity with the adsorbing material is adsorbed mainly to the adsorbing material than the to-be-removed component having a high affinity.
The multistage adsorption treatment apparatus for exhaust gas according to claim 1. The exhaust gas multistage adsorption treatment apparatus according to claim 1 or 2, wherein the adsorbent is spherical activated carbon. An adsorbing part in which exhaust gas containing at least two kinds of components to be removed comes into contact with the adsorbent and the components to be removed are adsorbed on the adsorbent, and the components to be removed adsorbed on the adsorbent are desorbed and An exhaust gas multi-stage adsorption treatment method using an exhaust gas multi-stage adsorption treatment device that continuously treats the exhaust gas by bringing the regenerated adsorbent into contact with the exhaust gas again. And
The exhaust gas is sequentially circulated through at least two or more adsorbing portions having a single type of adsorbent that can adsorb the component to be removed and has a difference in affinity with the component to be removed. In addition, the adsorbent is caused to flow while facing the flow direction of the exhaust gas, and the adsorbent and the exhaust gas are contacted to bring the components to be removed in descending order of affinity with the adsorbent. Adsorb to the adsorbent,
The adsorbent is transferred from each adsorbing section to a one-stage desorbing section, the to-be-removed component adsorbed on the adsorbent is desorbed, and the adsorbent is regenerated.
Returning the regenerated adsorbent to each adsorber;
A multi-stage adsorption treatment method for exhaust gas characterized by the above. The adsorption part is composed of two stages,
Of the adsorbing part, the adsorbing part in the previous stage mainly adsorbs the to-be-removed component having a high affinity with the adsorbing material among the to-be-removed components to the adsorbing material,
Of the adsorbing part, in the latter adsorbing part, the to-be-removed component having lower affinity with the adsorbing material than the to-be-removed component having high affinity is mainly adsorbed to the adsorbing material.
The multistage adsorption treatment method for exhaust gas according to claim 4. 6. The exhaust gas multistage adsorption treatment method according to claim 4, wherein spherical activated carbon is used as the adsorbent.

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