JPH0999210A - Solvent gas treating device and solvent gas treating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make treating efficiency excellent and to enable to use an adsorbent repeatedly. SOLUTION: In a solvent gas treating device provided with an adsorption tower 1 having an adsorption part 4 in which raw gas containing a solvent is introduced and brought into contact with an adsorbent 12, while the adsorbent 12 is fluidized, and the solvent in the raw gas is adsorbed with the adsorbent 12, the adsorbent 12 consists of a high polymer and a blower 13 is disposed at the upstream side of the adsorption tower 1 so as to be forcedly fed with the raw gas into the adsorption tower 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a solvent gas treatment apparatus and a solvent gas treatment method for removing harmful exhaust gas containing an organic solvent discharged from a factory or the like and discharging it as purified gas.

[0002]

2. Description of the Related Art A conventional apparatus for purifying a gas containing a solvent discharged from a factory using an organic solvent such as a coating factory, a printing factory, a chemical factory and a magnetic tape manufacturing factory is shown in FIG. A fluidized bed type solvent gas treatment apparatus using such spherical activated carbon has been used.

That is, it has a multi-stage fluidized bed that moves while moving the adsorbent 42 made of spherical activated carbon from above to below, and introduces the raw gas from a raw gas inlet port 35a to which a raw gas inlet passage 35 is connected. An adsorption tower 31 for countercurrently contacting the raw gas with the adsorbent 42 flowing in the fluidized bed 34 to adsorb the solvent to the adsorbent 42 and discharging the solvent-free gas, and the adsorption tower 31.
The adsorbent 42 that has adsorbed the solvent in 31 is transferred, and while the adsorbent 42 is heated by the heating means 34 such as water vapor to the boiling point of the solvent, a desorption gas composed of outside air or nitrogen gas is brought into countercurrent contact, and the solvent And a desorption tower 32 that desorbs the adsorbent 42 from the adsorbent 42. The adsorbent 42 desorbed in the desorption tower 32 is transferred to the adsorption tower 31 again and repeatedly used as the adsorbent 42.

Further, the desorbed gas after desorbing the adsorbent 42 passes from the desorbed gas discharge passage 40 through the condenser 45,
After desorption, the solvent component contained in the gas is cooled, condensed, and collected in the collection unit.

As a means for introducing the raw gas into the adsorption tower 31, a blower 44 provided in the purified gas discharge passage 36 is used.
Is provided so that the raw gas is sucked into the adsorption tower 31 from the raw gas introduction passage 35.

[0006]

In such a solvent gas treatment apparatus, since the spherical activated carbon is used as the adsorbent 42 as described above, the adsorbent 42 is made to flow in the fluidized bed 14 or at the time of transfer. The activated carbon may be worn by coming into contact with each other or the inner wall of the transfer path, and black powder may be mixed in the purified gas. Further, when the activated carbon is worn in this way, the volume of the activated carbon is reduced and the treatment capacity is reduced, or when the solvent is desorbed from the adsorbent 42 in the desorption tower 32, the adsorbent 42 reaches a temperature at which the solvent is desorbed. In order to heat the adsorbent 42, especially in the case of a solvent which is desorbed at a high temperature, the adsorbent 42 is thermally deteriorated by the heating, so that it is difficult and uneconomical to repeatedly use the adsorbent 42 for a long time. In addition, activated carbon cannot adsorb high-humidity raw gas because it adsorbs water, and since it has a catalytic action, the quality of the recovered solvent is low and there are problems such as alteration.

As a means for introducing the raw gas into the adsorption tower 31, a blower 44 is provided in the purified gas discharge passage 36, and the adsorption tower 31 is sucked by the blower 44 to feed the raw gas from the raw gas inlet port 35a. Since it is introduced into the adsorption tower 31, the inside of the adsorption tower 31 is depressurized from the outside. When the adsorbent 42 adsorbs the solvent, it is easier to adsorb under a slightly pressurized condition, but when the pressure inside the adsorption tower 31 is reduced as described above, it becomes difficult to adsorb the solvent, and adsorption in the adsorption tower 31 occurs. There was a problem that the efficiency was lowered.

The present invention has been made in order to solve such problems, and provides a solvent gas treatment apparatus and a solvent gas treatment method which have high treatment efficiency and can repeatedly use an adsorbent. This is an issue.

[0009]

[Means for Solving the Problems]

(Constitution) The present invention has been made in order to solve such a problem.
What was made as a solvent gas treatment device and its method, the feature of the solvent gas treatment device is to introduce a raw gas containing a solvent, and to bring the adsorbent 12 into contact with the raw gas while flowing the solvent, and the solvent in the raw gas. In a solvent gas treatment apparatus comprising an adsorption tower 1 having an adsorption section 4 for adsorbing the adsorbent 12 on the adsorbent 12, the adsorbent 12 is made of a polymer, and the raw gas is adsorbed on the upstream side of the adsorption tower 1 in the adsorption tower 1. There is a blower 13 provided to pump to.

The characteristics of the solvent gas treatment method are as follows:
The raw gas containing the solvent introduced into the adsorption tower 1 is transferred to the adsorption tower 1
In the solvent gas treatment method of adsorbing the solvent to the adsorbent 12 by bringing the solvent into contact with the adsorbent 12 flowing in the adsorbing section 4 in the solvent gas treatment method, the adsorbent 12 is composed of a polymer. The blower 13 provided on the upstream side of the adsorption tower 1 feeds the raw gas under pressure and introduces it into the adsorption tower 1.

(Operation) As described above, in the present invention, since the adsorbent composed of the polymer is used as the adsorbent 12, it is not repeatedly worn for a long time and is not thermally deteriorated by heat during desorption. can do.
Also, because it is an adsorbent artificially formed from a polymer,
It is also possible to easily adjust the particle size, density, mechanical strength, etc. of the adsorbent 12 appropriately so as to enhance the adsorption capacity for the solvent depending on the type of the solvent. Further, since it is an adsorbent formed of a polymer, it does not adsorb water like activated carbon, and can process a high-humidity raw gas. Furthermore, the quality of the recovered solvent is high because it does not have the catalytic action of activated carbon.

Further, in order to introduce the raw gas into the adsorption tower 1, the raw gas is pressure-fed to the adsorption tower 1 by a blower 13 provided upstream of the adsorption tower 1, so that the inside of the adsorption tower 1 is slightly pressurized. It becomes a state. Therefore, the inside of the adsorption tower 1 becomes a favorable environment for adsorbing the solvent to the adsorbent 12, and the adsorption efficiency is improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, the configuration of the solvent gas treatment device will be described. 1 shown in FIG. 1 is provided with a raw gas introduction port 5a to which a raw gas introduction passage 5 is connected at the bottom,
Adsorption having a multi-stage fluidized bed 4 as an adsorption part in which a raw gas containing a solvent is introduced from the raw gas introduction port 5a and the adsorbent 12 flows from the uppermost stage to the lowermost stage in order to adsorb the raw gas. It is a tower.

A blower 13 is provided in the raw gas introducing passage 5, and the adsorption tower 1 is introduced from the raw gas introducing port 5a by the blower 13.
Raw gas is pumped inside. The adsorbent 12 is formed of a polymer such as a synthetic resin, and the material of the polymer, the size of the pores, the density, the particle size, etc. are appropriately selected according to the type of the solvent to be adsorbed so that the adsorbability for the solvent is high. To be selected.

A purified gas outlet 6a, to which a gas outlet 6 is connected, is provided above the adsorption tower 1.

Reference numeral 2 is a desorption column into which an adsorbent 12 having adsorbed the solvent that has been moved to the lowest stage in the multi-stage fluidized bed 4 is introduced through an adsorbent transfer path 7, and inside the desorption column 2. Adsorbent 12
A moving part 14 is formed to drop and move the lower part of the desorption tower 2. The desorption tower 2 is provided with a steam introduction path 15, and the moving part 14 is moved by the steam introduced from the steam introduction path 15.
The adsorbent 12 falling through is indirectly heated to a temperature suitable for desorbing the solvent.

The numeral 8 is an adsorption unit provided under the moving unit 14 for returning the adsorbent 12 regenerated by desorbing the solvent in the desorption tower 2 to the uppermost part of the multi-stage fluidized bed 4 in the adsorption tower 1. It is the agent return route.

Reference numeral 9 denotes a desorption gas introduction passage for introducing the outside air as a desorption gas from below the desorption tower 2. The desorption gas introduction passage 9 is provided with a blower 18, and the desorption gas is removed by the blower 18. The pressure is fed into the desorption tower 2, and the pressure causes the desorption tower 2 to flow upward from below.

Reference numeral 10 denotes a post-desorption gas discharge passage for discharging the post-desorption gas containing the solvent after desorbing the solvent contained in the adsorbent 12 in the desorption tower 2. A condenser 16 is connected to the post-desorption gas discharge path 10 to cool and condense the solvent contained in the post-desorption gas, and the condensed solvent is recovered in a solvent recovery section 17 connected downstream of the condenser 16. Is formed. Although the solvent is collected in the present embodiment, a combustion device for removing the solvent by catalytic oxidation or direct combustion may be arranged in the post-desorption gas discharge passage 10 in addition to this.

Next, the case where the solvent is removed from the raw gas containing the solvent discharged from a factory or the like by the solvent gas treatment apparatus having the above-mentioned structure will be described.

First, a raw gas containing a solvent is blown by a blower 13 provided in a raw gas introduction passage 5 connected to the adsorption tower 1 from a raw gas introduction port 5a provided at a lower portion of the adsorption tower 1 to the adsorption tower 1 Introduce by pumping inside. The raw gas introduced into the adsorption tower 1 is sent from the lower side to the upper side by the pumping force of the blower 13, and is brought into countercurrent contact with the adsorbent 12 moving from the upper stage to the lower stage in the fluidized bed 4. It

The inside of the adsorption tower 1 is in a slightly pressurized state as compared with the outside because the raw gas is pressure-fed by the blower 13 into the adsorption tower 1, and the adsorbent 12 becomes a solvent when pressurized. Since the solvent tends to be easily adsorbed, the solvent is easily adsorbed by the adsorbent 12 in the adsorption tower 1 in such a pressurized state.

Thus, the solvent contained in the raw gas is the adsorbent.
The purified gas, which has been adsorbed by 12 and has the solvent removed from the purified gas discharge port 6a in the upper part of the adsorption tower 1, is discharged to the outside through the purified gas discharge path 6.

On the other hand, the adsorbent 12 which has been fluidized in the multi-stage fluidized bed 4 and adsorbed the solvent is introduced to the desorption tower 2 from the adsorbent transfer passage 7 after being moved to the lowest stage. The adsorbent 12
Is dropped in the moving part 14 in the desorption tower 2 while being indirectly heated to the temperature required for desorption by the steam introduced from the steam introducing passage 15. The temperature required for this desorption is
It is appropriately determined according to the type of solvent, the material of the adsorbent 12, and the like.

Further, in the desorption tower 2, the outside air is introduced as the desorption gas from the desorption gas introduction path 9 into the desorption tower 2 by a blower 18 provided in the desorption gas introduction path 9, and the blower is blown. The desorption gas is made to flow from the lower part to the upper part in the desorption tower by the pressure feeding force of 18.

Therefore, the solvent adsorbed on the adsorbent 12 is desorbed, and the desorbed solvent is carried to the upper part of the desorption tower 2 by the desorption gas and transferred to the lower part of the desorption tower 2. Is transferred to the uppermost stage of the fluidized bed of the adsorption tower 1 through the adsorbent return passage 8, and is fluidized again in the fluidized bed 4 as the adsorbent 12.

The desorbed gas after desorbing the solvent is desorbed from the desorbed gas discharge passage 10 in the upper part of the desorbing tower 2 to the desorbing tower 2.
The solvent contained in the post-desorption gas is cooled and condensed by the condenser 16 connected to the post-desorption gas discharge path 10 and is collected in the solvent recovery section 17.

In the example of the above embodiment, the desorption tower 2
The blower 18 provided in the desorption gas introduction passage 9 was used as a means for introducing the desorption gas into the interior of the desorption tower 2. The blower is installed in the rear gas exhaust passage 10.
The inside of the desorption tower 2 may be sucked by 18 and the desorption gas may be drawn into the desorption tower 2 from the desorption gas introduction passage 9 connected to the desorption tower 2. In this case, the inside of the desorption tower 2 is sucked by the blower 18 and is in a slightly reduced pressure state as compared with the outside,
Therefore, there is an advantage that the solvent is easily desorbed from the adsorbent 12 and the desorption efficiency is improved.

Further, in the above embodiment, the desorption tower 2
Although steam was used as a heating means for desorbing the adsorbent 12 in the inside, the heating means is not limited to this, and for example, a heating medium other than steam or a heater is used,
Alternatively, the desorption gas may be preheated, and the adsorbent 12 may be desorbed by heating the adsorbent 12 to a predetermined temperature by the heat of the desorption gas.

Further, as a means for transferring the adsorbent 12 in the desorption tower 2, in addition to the moving section 14 provided so as to drop from the upper portion to the lower portion as in the above embodiment, the adsorption of the adsorption tower 1 It may be a multi-stage fluidized bed such as a section.

Further, in the above embodiment, the adsorbent 12 to be desorbed by introducing the outside air into the desorption tower 2 as the desorption gas.
However, nitrogen gas or the like may be used as the desorption gas.

In the above embodiment, the solvent recovery section 17 is arranged in the post-desorption gas exhaust path 10 to recover the solvent. However, in addition to such a solvent recovery section 17, the removed solvent is used as a catalyst. A combustion device that oxidizes or directly burns and removes the solvent may be provided instead of the solvent recovery unit 17.

[0033]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, since the adsorbent is made of a polymer, it is less likely to be worn or thermally deteriorated, can be repeatedly used as an adsorbent, is economical, and has high efficiency. Since it is easy to adjust the molecule adsorption performance, it is possible to form an adsorbent more suitable for the solvent to be treated.

As a means for introducing the raw gas into the adsorption tower, a blower is provided on the upstream side of the adsorption tower, and the raw gas is pressure-fed by the blower and introduced into the adsorption tower. It becomes a pressure state. Therefore, the solvent is easily adsorbed by the adsorbent in the adsorption tower, the adsorption efficiency is improved, and the raw gas can be efficiently purified.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a solvent gas treatment device as an example of an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a solvent gas treatment device according to another embodiment.

FIG. 3 is a schematic configuration diagram of a conventional solvent gas treatment device.

[Explanation of symbols]

 1 Adsorption tower 2 Desorption tower 4 Multi-stage fluidized bed (adsorption section) 6 Gas outlet 8 Adsorbent return path (return path) 12 Adsorbent 13 Blower 18 Blower

Claims (2)

[Claims] 1. An adsorbent (12) in which a raw gas containing a solvent is introduced.
Adsorption column having an adsorption part (4) for adsorbing the solvent in the raw gas to the adsorbent (12) by bringing the solvent into contact with the raw gas while flowing
In the solvent gas treatment device comprising (1), the adsorbent
A solvent gas treatment apparatus characterized in that (12) is made of a polymer, and a blower (13) is provided on the upstream side of the adsorption tower (1) to pressure-feed the raw gas into the adsorption tower (1). . 2. The solvent is adsorbed by bringing the raw gas containing the solvent introduced into the adsorption tower (1) into contact with the adsorbent (12) flowing in the adsorption section (4) in the adsorption tower (1). In the solvent gas treatment method of discharging the gas from which the solvent has been removed after being adsorbed by (12), the adsorbent (12) is made of a polymer, and a blower provided on the upstream side of the adsorption tower (1). A solvent gas treatment method characterized in that the raw gas is pressure-fed by (13) and introduced into the adsorption tower (1).