JP2006122774A - Detoxification apparatus of chlorine type solvent in exhaust gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detoxification apparatus of a chlorine type solvent in an exhaust gas capable of treatment the exhaust gas firstly over a range from a large flow rate to a small flow rate by one apparatus, capable of certainly removing a chlorine type solvent secondly, capable of detoxifying a harmful produced substance thirdly, capable of confirming the breakthrough progress state of the adsorbent (activated carbon) in an adsorbing/desorbing tank fourthly and capable of reducing the running cost fifthly. <P>SOLUTION: The detoxification apparatus 1 is constituted so that a large flow rate of the exhaust gas A containing the chlorine type solvent is supplied to the adsorbing/desorbing tank 3 to adsorb the chlorine type solvent by the adsorbent 9 and the chlorine type solvent adsorbed by the adsorbent 9 is desorbed by the hot air C from a hot air supply part 4. A plasma reactor 5 is constituted so that a small flow rate of the exhaust gas containing the chlorine type solvent is supplied or a small flow rate of the secondary exhaust gas containing the chlorine type solvent desorbed from the adsorbing/desorbing tank 3 is supplied to decompose the chlorine type solvent by plasma discharge and an oxidation catalyst part 6 or a collection and neutralization tank 7 is also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for detoxifying a chlorinated solvent in exhaust gas. That is, the present invention relates to a processing apparatus for detoxifying a chlorinated solvent contained in exhaust gas.

《Technical background》
Exhaust gas containing chlorinated solvents is exhausted from various industrial and chemical treatment processes, and if released into the atmosphere as it is, it is harmful to the human body and the environment, and it is also a cause of suspended particulate matter PM and photochemical smog. Become.
Therefore, a heat storage combustion device and other detoxification treatment devices are attached to the exhaust gas exhaust port containing the chlorinated solvent for environmental measures.

<Conventional technology>
A heat storage combustion apparatus, which is a representative example of this kind of detoxification processing apparatus, has been made of the following method, for example.
That is, in the heat storage combustion apparatus, exhaust gas containing a chlorinated solvent is supplied to and passed through a ceramic heat storage body with a honeycomb structure. First, it is ignited with a seed fire, the combustion heat is stored in the heat storage body, and the exhaust gas supplied afterwards is ignited based on contact with each cell wall of the heat storage body.
Therefore, by such a circulation system, the chlorinated solvent contained in the exhaust gas is burned and removed, and the exhaust gas is released to the atmosphere.

By the way, the following problems have been pointed out with respect to such a conventional example.
<About the first problem>
First, a problem has been pointed out that a heat storage combustion apparatus, which is a representative example of this type of detoxification processing apparatus, requires an apparatus suitable for the flow rate of exhaust gas.
That is, in the heat storage combustion apparatus, as described above, since the exhaust gas is ignited and burned based on the contact with the heat storage body, the contact time between the exhaust gas and the heat storage body is important. Therefore, there is a demand for a heat storage body having a size suitable for the flow rate of exhaust gas. In the case of exhaust gas with a small flow rate of about 100 m ³ / hr, a small device equipped with a small size heat storage body is used exclusively. Has been. Further, in the case of exhaust gas having a large flow rate of about 1,000 m ³ / hr, a large apparatus having a large-sized heat accumulator is used exclusively.
As described above, it is necessary to use a large-sized and small-sized heat storage combustion device depending on the flow rate of the exhaust gas, and problems have been pointed out in terms of equipment cost and work efficiency.

About the second problem
Secondly, it has been pointed out that the heat storage combustion device and other detoxification treatment devices of this kind are uncertain and unreliable in removing and cleaning the chlorinated solvent in the exhaust gas.
For example, in a heat storage combustion device, the contact time between the exhaust gas and the heat storage body does not match, the processing time is often insufficient, and the high density of the chlorinated solvent in the exhaust gas is essential for processing. In many cases, exhaustion gas containing unburned chlorinated solvent is easily released to the atmosphere due to demands and the like.

<< About the present invention >>
In view of such circumstances, the apparatus for detoxifying a chlorinated solvent in exhaust gas according to the present invention has been made in order to solve the problems of the conventional example.
In addition, an adsorption / desorption tank with a hot air supply unit and a plasma reactor are used in combination in a two-stage configuration in series and in parallel, and an oxidation catalyst unit and a trapping summing tank are also provided. Further, the present invention is characterized in that a temperature detecting means is provided at each height level of the adsorption / desorption tank, and a hot air supply unit and a plasma reactor are driven in the nighttime power band.
Therefore, according to the present invention, first, from a large flow rate of exhaust gas to a small flow rate of exhaust gas, one unit can handle and process, and secondly, the chlorinated solvent can be removed reliably, and the exhaust gas is sufficiently cleaned Third, harmful product substances in the middle are made harmless, and fourth, the progress of breakthrough of the adsorbent (activated carbon) in the adsorption / desorption tank can be grasped. The object is to propose a detoxifying device for chlorine solvent in exhaust gas that can be reduced.

<About each claim>
The technical means of the present invention for solving such a problem is as follows. First, claim 1 is as follows.
An apparatus for detoxifying a chlorinated solvent in exhaust gas according to claim 1 is a detoxifying apparatus for chlorinated solvent contained in exhaust gas, comprising a supply port, an adsorption / desorption tank, a hot air supply unit, a plasma reactor. Etc.
The adsorption / desorption tank is filled with an adsorbent, and a large amount of exhaust gas containing a chlorinated solvent is supplied from the supply port to adsorb the chlorinated solvent to the adsorbent, thereby rendering it harmless. Exhaust gas can be discharged from the exhaust port to the atmosphere.
The hot air supply unit can supply hot air to the adsorption / desorption tank, and the hot air can desorb the chlorinated solvent adsorbed by the adsorbent in the adsorption / desorption tank.
The plasma reactor is supplied with a small flow rate of exhaust gas containing a chlorinated solvent from the supply port, or hot air gas containing a chlorinated solvent desorbed from the adsorbent in the adsorption / desorption tank, that is, a small amount of gas. A secondary exhaust gas having a flow rate is supplied. And it is characterized by decomposing | disassembling the chlorine-type solvent of those exhaust gas by plasma discharge, and releasing the detoxified exhaust gas to air | atmosphere.

Claim 2 is as follows. The device for detoxifying a chlorinated solvent in exhaust gas according to claim 2 further comprises an oxidation catalyst unit and a trapping sum tank in claim 1.
Then, the exhaust gas that has passed through the plasma reactor is supplied to the oxidation catalyst portion, and the remaining chlorinated solvent can be decomposed by the oxidation catalyst.
The trapping and summing tank is supplied with exhaust gas from the oxidation catalyst section, neutralizes and collects harmful product substances accompanying decomposition by the trapping and summing solution, and discharges the harmless exhaust gas to its outlet. It can be released from the atmosphere to the atmosphere.
Claim 3 is as follows. An apparatus for detoxifying a chlorinated solvent in exhaust gas according to claim 3 is characterized in that, in claim 1 or 2, the adsorption / desorption tank comprises an exhaust gas inlet provided at a lower end and an exhaust provided at an upper end. The gas discharge port, the activated carbon filled inside as the adsorbent, and temperature detection means are provided.
The temperature detecting means is provided in a plurality according to the filling height level of the activated carbon. As the activated carbon gradually adsorbs and breaks through the chlorinated solvent, the temperature detecting means gradually advances from the bottom to the top. It detects the temperature change of heat generation and heat release that gradually progress from bottom to top. Therefore, the progress of breakthrough of the activated carbon can be constantly confirmed based on the detected temperature change.

Claim 4 is as follows. The detoxification treatment apparatus for chlorinated solvent in exhaust gas according to claim 4 is the same as that of claim 1, even if the exhaust gas has a small flow rate. , Not to the plasma reactor, but to the adsorption / desorption tank.
At the same time, hot air is supplied from the hot air supply unit to the adsorption / desorption tank in the nighttime power band, and the secondary exhaust gas supplied from the adsorption / desorption tank is chlorinated by plasma discharge in the plasma reactor. An apparatus for detoxifying a chlorinated solvent in exhaust gas, characterized in that the exhaust gas detoxified by decomposing the system solvent can be released to the atmosphere.
Claim 5 is as follows. An apparatus for detoxifying a chlorinated solvent in exhaust gas according to claim 5 is characterized in that, in claim 1, the hot blast supply unit supplies hot air having a temperature of about 1.88 times the boiling point of the chlorinated solvent at a low flow rate. It can be supplied to the adsorption / desorption tank.

<About action>
The detoxification apparatus for chlorine solvent in exhaust gas according to the present invention is as described above, and is as follows.
(1) The supplied exhaust gas is supplied to the adsorption / desorption tank when the flow rate is large, and is supplied to the plasma reactor when the flow rate is small.
(2) The exhaust gas supplied to the adsorption / desorption tank is released to the atmosphere after the chlorinated solvent is adsorbed and removed by the adsorption / desorption tank. When the adsorption is completed, hot air having a temperature of about 1.88 times the boiling point of the chlorinated solvent is supplied from the hot blast supply unit to the adsorption / desorption tank at a small flow rate, and the adsorbed chlorinated solvent is desorbed, Secondary exhaust gas containing a chlorinated solvent is supplied to the plasma reactor. (3) A small amount of exhaust gas or secondary exhaust gas is supplied to the plasma reactor, so that the chlorinated solvent is decomposed and removed by plasma discharge.
(4) Then, the exhaust gas is supplied to the oxidation catalyst unit, and the remaining chlorinated solvent is decomposed and removed.
(5) Finally, the exhaust gas is supplied to the trapping and summing tank, and harmful product substances accompanying the decomposition are neutralized and collected and released into the atmosphere.

(6) The detoxification processing apparatus is as described above. As described above, first, a large flow rate of exhaust gas is adjusted to a small flow rate using the adsorption / desorption of the adsorption / desorption tank, and then supplied to the plasma reactor. To be supplied. The adsorption / desorption tank can treat a large flow rate of exhaust gas, and the plasma reactor is suitable for the treatment of a small flow rate of exhaust gas, and a process that matches each is performed.
Therefore, the single detoxification treatment apparatus can treat both a large flow rate exhaust gas containing a chlorinated solvent and a small flow rate exhaust gas.
(7) In this detoxification treatment apparatus, a large amount of exhaust gas is released into the atmosphere after the chlorinated solvent is reliably adsorbed and removed in the adsorption / desorption tank. A small amount of exhaust gas and secondary exhaust gas that passes through the adsorption / desorption tank are released into the atmosphere after the chlorinated solvent is reliably decomposed and removed by the plasma reactor and the oxidation catalyst section. Thus, this detoxification processing apparatus can reliably remove the chlorinated solvent.
(8) Further, in this detoxification treatment apparatus, harmful product substances accompanying the decomposition of the chlorinated solvent are neutralized and collected in the collection concentration tank, and then released into the atmosphere. In this way, harmful product substances are also removed.

(9) By the way, in the adsorption / desorption tank of the detoxification treatment apparatus, adsorption and breakthrough of the chlorinated solvent, and heat generation and heat release accompanying this progress from the bottom to the top for the activated carbon that is the adsorbent. . Therefore, by providing temperature detection means at each height level and monitoring temperature changes, the progress of breakthrough can be grasped in a timely manner and overall breakthrough can be predicted. Is also prevented.
(10) It should be noted that this detoxification processing apparatus can also perform the following processing regardless of the above. That is, even if the exhaust gas has a small flow rate, it is supplied to the adsorption / desorption tank during the day to adsorb the chlorinated solvent, and the dehumidified chlorinated solvent is driven at night by driving the hot air supply unit and the plasma reactor. Disassemble and remove. In this case, since the hot air supply unit and the plasma reactor are driven in the night power band, particularly in the late night power band, the electricity bill is reduced.
Of course, even in the case of exhaust gas with a large flow rate, the electricity cost can be reduced by supplying the gas to the adsorption / desorption tank during the day and driving the hot air supply unit and the plasma reactor at night.

<Features of the present invention>
In this way, the detoxification treatment apparatus for chlorinated solvent in exhaust gas according to the present invention employs a combination of an adsorption / desorption tank with a hot air supply unit and a plasma reactor in a two-stage configuration in series and parallel, It also has an oxidation catalyst part and a trapping concentration sump tank. Further, the present invention is characterized in that a temperature detecting means is provided at each height level of the adsorption / desorption tank, and a hot air supply unit and a plasma reactor are driven in the nighttime power band.
Therefore, the present invention exhibits the following effects.

<< First effect >>
First, a single unit can handle and process a large flow rate of exhaust gas to a small flow rate of exhaust gas.
That is, in the detoxification processing apparatus of the present invention, a large flow rate of exhaust gas is reduced in flow by the adsorption / desorption tank and supplied to the plasma reactor, and a small flow rate of exhaust gas is directly supplied to the plasma reactor. Therefore, a single unit can treat both a large flow rate exhaust gas containing a chlorinated solvent and a small flow rate exhaust gas. That is, one unit can cope with exhaust gases of various air volumes containing a chlorinated solvent.
As in the above-described conventional example, there is no need to always use a large device dedicated to a large flow rate exhaust gas and a small device dedicated to a small flow rate exhaust gas. Therefore, it is excellent in equipment cost and work efficiency.

<< Second effect >>
Second, the chlorinated solvent can be removed reliably, and the exhaust gas is sufficiently cleaned and released into the atmosphere.
That is, in the detoxification treatment apparatus of the present invention, the chlorinated solvent contained in the exhaust gas at a large flow rate is adsorbed and removed by the adsorbent in the adsorption / desorption tank, and the exhaust gas thus cleaned is released into the atmosphere. Is done. Chlorine solvents contained in the exhaust gas with a small flow rate and chlorine solvents desorbed from the adsorption / desorption tank are decomposed and removed by the plasma reactor, and further decomposed and removed by the oxidation catalyst section just in case. Thus, the exhaust gas that has been cleaned is released into the atmosphere.
The exhaust gas containing a chlorinated solvent is reliably prevented from being released into the atmosphere as in the above-described conventional example. Of course, the emission regulation of the volatile organic compound VOC can be sufficiently satisfied.

《Third effect》
Thirdly, harmful product substances in the middle are also rendered harmless. That is, the detoxification treatment apparatus of the present invention includes a trapping sum tank, and neutralizes and collects harmful product substances accompanying the decomposition of chlorinated solvents. Therefore, the exhaust gas which has been made harmless and sufficiently cleaned from this aspect is released into the atmosphere.

<< 4th effect >>
Fourth, it is possible to constantly grasp the progress of breakthrough of activated carbon in the adsorption / desorption tank. That is, in the detoxification processing apparatus of the present invention, temperature detection means is provided at each level of the adsorption / desorption tank, and the progress of breakthrough of activated carbon, which is an adsorbent during adsorption of a chlorinated solvent, can always be confirmed.
Therefore, it is possible to predict the overall breakthrough of the activated carbon in advance, the adsorption / desorption tank can function normally at all times, and the activated carbon can be used efficiently without waste.

《Fifth effect》
Fifth, running costs can be reduced by using nighttime power. That is, in the detoxification treatment apparatus of the present invention, a small amount of exhaust gas is supplied to an adsorption / desorption tank during the day to adsorb and remove the chlorinated solvent, and at night, a hot air supply unit or a plasma reactor is used. A method of decomposing and removing the desorbed chlorine-based solvent can also be implemented. Of course, in the case of exhaust gas having a large flow rate, a method of adsorbing during the day and decomposing at night can be easily implemented.
In these cases, since nighttime power, particularly late-night power, is used, the cost of electricity is reduced and the running cost is improved.
As described above, the effects exerted by the present invention are remarkably large, such as all the problems existing in this type of conventional example are solved.

《About drawing》
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus for detoxifying a chlorinated solvent in exhaust gas according to the present invention will be described in detail based on the best mode for carrying out the invention shown in the drawings.
FIG. 1 is an explanatory front view of the entire configuration. FIG. 2 shows a plasma reactor, where (1) is a side view and (2) is a perspective view.

<< About the outline of the detoxification processing apparatus 1 >>
The detoxification treatment apparatus 1 detoxifies the chlorinated solvent contained in the exhaust gas A. And as shown in FIG. 1, the supply port 2, the adsorption / desorption tank 3, the hot-air supply part 4, the plasma reactor 5, the oxidation catalyst part 6, the collection concentration sum tank 7, the blower 8, etc. are provided.
These components are arranged based on the mutual positional relationship and the vertical relationship as shown in FIG. Further, as a chlorinated solvent that is vaporized and gasified in the exhaust gas A (the vaporized and gasified chlorinated solvent is hereinafter simply referred to as a chlorinated solvent), trichlorethylene C ₂ HCl ₃ (commonly called TCE) And dichloromethane CH ₂ Cl ₂ are typical, but other chlorinated solvents are also conceivable. Hereinafter, these will be sequentially described.

<< About the adsorption / desorption tank 3 >>
First, the adsorption / desorption tank 3 will be described. The adsorption / desorption tank 3 of the detoxification treatment apparatus 1 is filled with an adsorbent 9, and a large flow of exhaust gas A containing a chlorinated solvent is supplied from the supply port 2 of the detoxification treatment apparatus 1, The contained chlorinated solvent is adsorbed by the adsorbent 9, and the detoxified exhaust gas A can be discharged from the outlet 10 to the atmosphere B. Exhaust gas A having a large flow rate refers to a flow rate exceeding 100 m ³ / hr, for example.
The adsorption / desorption tank 3 includes an exhaust gas A inlet 11 provided on the side of the lower end, an exhaust 10 of exhaust gas A provided on the upper end, and a carbon material filled inside as an adsorbent 9. Activated carbon 12, a wire mesh 14 that holds the activated carbon 12, and temperature detection means 13.

A plurality of temperature detection means 13 are provided according to the filling height level of the activated carbon 12. Then, with respect to the filled activated carbon 12, the adsorption and breakthrough of the chlorinated solvent gradually proceeds stepwise from bottom to top, and gradually proceeds stepwise from bottom to top. Detect temperature change of heat generation and heat release. Therefore, the progress of breakthrough of the activated carbon 12 can always be confirmed based on the detected temperature change.
In the illustrated example, a thermoelectric material is used as the temperature detecting means 13, and the adsorption / desorption tank 3 is provided at each of an upper part, a central part, and a lower part, and thus a total of three are provided.
The chlorinated solvent generates heat when adsorbed on the activated carbon 12, and the activated carbon 12 also generates heat. Then, when the adsorption capacity of the activated carbon 12 is saturated due to adsorption of the chlorinated solvent and it becomes difficult to adsorb and breaks through, the adsorption is stopped and the adsorption of the adsorbed chlorinated solvent and the activated carbon 12 is also stopped.
The temperature detection means 13 at each height level detects such a temperature change for the activated carbon 12 at each height level and displays it on the display unit. That is, a temperature change that is low before adsorption, high at the time of adsorption, and low again due to breakthrough occurs sequentially for each of the lower, central, and upper height levels of the activated carbon 12, and the temperature detection means 13 sequentially detects this. indicate. The operator can always confirm the breakthrough progress of the activated carbon 12 by viewing this display.
The adsorption / desorption tank 3 is as described above.

<< About hot air supply part 4 >>
Next, the hot air supply unit 4 will be described. The hot air supply unit 4 of the detoxification treatment apparatus 1 can supply the hot air C to the adsorption / desorption tank 3, and the hot air C can desorb the chlorinated solvent adsorbed by the adsorbent 9 in the adsorption / desorption tank 3. It has become.
That is, a hot air supply unit 4 is attached to the adsorption / desorption tank 3, and the hot air supply unit 4 includes a heater and a blower, and converts the intake air B into hot air C at a low flow rate of about 100 m ³ / hr. It can be supplied to the adsorption / desorption tank 3.
The temperature of the supplied hot air C is set to about 1.88 times the boiling point of the chlorinated solvent in view of being used for desorption of the adsorbed chlorinated solvent. For example, the boiling point of trichlorethylene is 87 ° C., and the hot air C is set to 164 ° C. or higher. The chlorinated solvent generally has a low boiling point of less than 100 ° C.
The hot air supply unit 4 is as described above.

<About the plasma reactor 5>
Next, the plasma reactor 5 will be described. The plasma reactor 5 of the detoxification treatment apparatus 1 is supplied with a small flow rate of exhaust gas A containing a chlorinated solvent from the supply port 2 of the detoxification treatment apparatus 1 or the adsorbent of the adsorption / desorption tank 3 described above. 9 is supplied with hot air C gas containing the chlorine-based solvent desorbed from 9, that is, secondary exhaust gas A having a small flow rate.
Then, the chlorinated solvent of the exhaust gas A can be decomposed by plasma discharge, and the detoxified exhaust gas A can be released to the atmosphere B.

Such a plasma reactor 5 will be further described in detail. First, the exhaust gas A having a small flow rate of, for example, a flow rate of 100 m ³ / hr or less is directly supplied to the plasma reactor 5 from the supply port 2. Further, for example, high flow exhaust gas A in the flow rate 100 m ³ / hr greater, based on the hot air C from the hot air supply unit 4 via the desorption vessel 3, is adjusted to a small flow rate of the flow rate 100 m ³ / hr, feed Is done.
For example, as shown in FIG. 2, the plasma reactor 5 is formed on the secondary side through a dielectric 16 such as a glass tube concentrically outside the central electrode 15 on the primary side with a circular cross section, with a distance D. The outer electrode 17 is arranged, and in the illustrated example, it has an outer diameter of 300 mm and a length of 200 mm. In the illustrated example, a total of eight such plasma reactors 5 are arranged in four rows and two rows.
Then, an AC 100V of 50H _Z of the primary power supply, for example 6kV at 15kV transformer converts the high voltage of 3mA, is energized.

When the plasma reactor 5 is energized and a voltage is applied between the center electrode 15 and the outer electrode 17, plasma discharge occurs. Accordingly, the exhaust gas A stays and passes through the plasma region generated at the interval D between the center electrode 15 and the outer electrode 17, so that the contained chlorinated solvent is decomposed.
That is, the accelerated fast electrons collide with the chlorinated solvent by the plasma discharge, and the chemical bond is easily broken. At the same time, by the plasma discharge, the generated oxygen O ₃ and the active oxygen species such as the oxygen O radical that the ozone O ₃ naturally decomposed react with the chlorine-based solvent and decompose into carbon dioxide CO ₂ and hydrogen chloride HCl. To do.
For example, when the chlorinated solvent is trichlorethylene C ₂ HCl ₃ , it is decomposed by the following chemical formula 1.

In the illustrated plasma reactor 5 as a whole, for example, when exhaust gas A having a small flow rate of 100 m ³ / hr is supplied, the exhaust gas A has a residence time of 4 seconds at a flow rate of 0.2 m / second. The time required for the decomposition of trichloroethylene ethylene C ₂ HCl ₃ is usually about 3 seconds.
The plasma reactor 5 is as described above.

<< Oxidation Catalyst 6 >>
Next, the oxidation catalyst unit 6 will be described. The oxidation catalyst unit 6 of the detoxification treatment apparatus 1 is supplied with the exhaust gas A that has passed through the plasma reactor 5, and the oxidation catalyst 18 can decompose the remaining chlorinated solvent.
That is, the oxidation catalyst portion 6 has a structure in which platinum and other oxidation catalysts 18 are supported on a metal carrier having a honeycomb structure. Then, the chlorinated solvent remaining in the passing exhaust gas A is oxidized by the catalytic action and decomposed into water H ₂ O, carbon dioxide gas CO _{2 and the} like.
The oxidation catalyst unit 6 is as described above.

<< About the catching sum tank 7 >>
Next, the trap concentration Japanese tank 7 will be described. The trapping sum tank 7 of the detoxification treatment apparatus 1 is supplied with the exhaust gas A from the oxidation catalyst unit 6 and neutralizes and collects harmful product substances accompanying the decomposition by the trapping sum solution 19 to be rendered harmless. The exhaust gas A can be discharged from the discharge port 20 to the atmosphere B.
The trapping sum tank 7 is filled with, for example, an aqueous solution of sodium hydroxide NaOH as a trapping sum solution 19. The trapped concentration solution 19 first neutralizes the harmful product produced as a result of decomposing the chlorinated solvent in the plasma reactor 5 in the previous step.
That is, harmful product substances, for example, hydrogen chloride HCl (refer to the chemical formula of Chemical Formula 1) contained in the exhaust gas A supplied to the trapping and summing tank 7, sodium hydroxide NaOH that is the trapping and summing solution 19. Is neutralized with the following chemical formula (2). That is, in the trapping and summing tank 7, hydrochloric acid HCl is decomposed into sodium chloride NaCl and water H ₂ O by the trapping and summing solution 19.

At the same time, the trapped concentration solution 19 is secondly ozone O _3, which is a harmful product that cannot be consumed and remains among the active oxygen species generated for the decomposition of the chlorinated solvent in the plasma reactor 5 in the previous step. To collect. That is, the ozone O ₃ remaining in the supplied exhaust gas A is collected by the water H ₂ O of the collection and concentration solution 19.
More specifically, first, the half-life of gaseous ozone O _{3 having} a concentration of 1% is about 16 hours, and the solubility of ozone O ₃ in water H ₂ O is 0.017 kg / 100 kg. is there. And the half-life of ₃ ppm ozone O ₃ dissolved in water is greatly reduced to about 30 minutes. In addition, the reaction between ozone O ₃ and sodium hydroxide NaOH, and the heat of neutralization of hydrogen chloride HCl and sodium hydroxide NaOH contained in the exhaust gas A supplied to the trapping and summing tank 7 as described above. As a result, the temperature of the trapped and concentrated solution 19 rises, and the half-life of ozone O ₃ is further shortened.
In this manner, ozone O _3, which is a harmful product, is collected and decomposed into oxygen O ₂ by the trapping concentration solution 19 in the trapping concentration tank 7 and disappears. In this way, the harmless exhaust gas A is released toward the atmosphere B.
The catching sum tank 7 is like this.

<Others>
First, in the figure, reference numeral 21 denotes a flow meter, which is attached downstream near the supply port 2 and measures the flow rate of the exhaust gas A supplied to the detoxification treatment apparatus 1.
Secondly, in the example described above, the large flow rate is more than 100 m ³ / hr and the small flow rate is 100 m ³ / hr or less, but the present invention is not limited to this. For example, the large flow rate is set between ^90m 3 / hr ultra ~150m ³ / hr, it may be set to a small flow rate during the following ^{90m 3} / ^hr~150m 3 / hr.
Thirdly, the blower 8 is attached to the supply port 2 and is driven when the pressure of the supplied exhaust gas A is insufficient.
Fourthly, the intervening and connected piping 22 is as follows. First, the piping 22 from the supply port 2 is branched halfway toward the adsorption / desorption tank 3 and the plasma reactor 5 along the way, and valves V1 and V2 are respectively attached thereto.
In addition, a pipe 22 from the adsorption / desorption tank 3 to the plasma reactor 5 is connected in the middle of the pipe 22 to the plasma reactor 5, and valves V3 and V4 are respectively attached immediately before the connection. Further, a pipe 22 is interposed to connect the plasma reactor 5, the oxidation catalyst unit 6, and the trapping and summing tank 7 in series.
Also, pipes 22 are interposed between the hot air supply unit 4 and the adsorption / desorption tank 3, the adsorption / desorption tank 3 and its discharge port 10, and the trapping and summing tank 7 and its discharge port 20, respectively. Are provided with valves V5 and V6, respectively.
The detoxification processing apparatus 1 is as described above.

《Action etc.》
The chlorine-based solvent detoxification treatment apparatus 1 in the exhaust gas A of the present invention is configured as described above. Therefore, it becomes as follows.
(1) Exhaust gas A containing a chlorinated solvent that is discharged from various industrial and chemical treatment steps and vaporized and gasified is supplied to the detoxification treatment apparatus 1.
The exhaust gas A supplied to the detoxification treatment apparatus 1 is first supplied from the supply port 2 to the adsorption / desorption tank 3 when the flow rate exceeds, for example, 100 m ³ / hr. On the other hand, for example, in the case of a small flow rate of 100 m ³ / hr or less, the plasma is first supplied from the supply port 2 to the plasma reactor 5.

(2) When the flow rate is large, the valve V is switched to V1 closed, valve V2 opened, valve V3 closed, valve V4 closed, valve V5 closed, and valve V6 opened.
Accordingly, the exhaust gas A having a large flow rate supplied to the lower part of the adsorption / desorption tank 3 rises in the adsorption / desorption tank 3, and the adsorbent 9 in which the contained chlorine-based solvent is filled in the adsorption / desorption tank 3. The exhaust gas A adsorbed and removed by the activated carbon 12 is rendered harmless, and is discharged from the discharge port 10 at the upper end portion to the atmosphere B.
When the adsorption in the adsorption / desorption tank 3 is completed, the valve V is switched to V1, V2, V3, V4, V5, and V6.
Accordingly, hot air C having a temperature of about 1.88 times the boiling point of the chlorinated solvent is supplied from the hot air supply unit 4 to the lower portion of the adsorption / desorption tank 3 at a small flow rate. Therefore, in the adsorption / desorption tank 3, the chlorinated solvent adsorbed on the activated carbon 12 of the adsorbent 9 is desorbed and desorbed by the hot air C, and thus, hot air C gas containing the desorbed and concentrated chlorine solvent, That is, the secondary exhaust gas A having a small flow rate is supplied to the plasma reactor 5 disposed at the upper level.

Specific examples are as follows. That is, a large flow rate of 1,000 m ³ / hr of exhaust gas A containing 50 ppm of gaseous trichlorethylene C ₂ HCl ₃ as a chlorinated solvent is supplied to the adsorption / desorption tank 3 for 8 hours (9.00 to 17.00). In this case, the amount of trichlorethylene C ₂ HCl ₃ supplied is as follows. In other words, the 1,000m ³ /hr×8hr×50ppm=0.4m ^3.
And then, a secondary exhaust gas A small flow rate 100 m ³ / hr of gaseous trichlorethylene _C 2 HCl ₃ to be desorbed from the desorption tank 3 enriched contained 500 ppm, 8 hours (23.00 to 7 .00), the amount of trichlorethylene C ₂ HCl ₃ supplied is as follows, and the same amount as above is supplied. In other words, the 100m ³ /hr×8hr×500ppm=0.4m ^3.

(3) The plasma reactor 5 is supplied with the small flow rate exhaust gas A directly supplied from the supply port 2 described above or the low flow rate secondary exhaust gas A via the adsorption / desorption tank 3 described above. Is done. In the former case, the valve V is switched to V1 open, V2 close, V3 open, V4 close, V5 close, and V6 close.
The exhaust gas A passing through the plasma reactor 5 is easily broken by the plasma generated by the voltage application of the contained chlorinated solvent, and the generated ozone O ₃ , oxygen O radicals, etc. It is decomposed by reacting with active oxygen species.
In this way, the exhaust gas A supplied to the plasma reactor 5 becomes exhaust gas A in which the contained chlorine-based solvent is decomposed and removed by plasma discharge, and thus rendered harmless.

  (4) The exhaust gas A that has passed through the plasma reactor 5 is then supplied to the oxidation catalyst unit 6. The exhaust gas A is reliably decomposed and removed by oxidizing the chlorinated solvent remaining without being decomposed and removed in the plasma reactor 5 by the oxidation catalyst 18 such as platinum in the oxidation catalyst section 6. It becomes the harmless exhaust gas A.

(5) The exhaust gas A that has passed through the oxidation catalyst unit 6 is finally supplied to the trapping and summing tank 7. The exhaust gas A is neutralized or collected by the trapped concentration solution 19 in the trapping concentration sump tank 7 with harmful product substances accompanying decomposition.
That is, first of all, harmful products such as hydrogen chloride HCl produced by the decomposition of the chlorinated solvent in the plasma reactor 5 are neutralized by the trapping and summing solution 19 such as an aqueous solution of sodium hydroxide NaOH. . At the same time, secondly, active oxygen species and harmful substances such as ozone O ₃ generated and remaining in the plasma reactor 5 are collected by the trapping and summing solution 19. Therefore, the exhaust gas A is also made harmless exhaust gas A from this surface and is discharged from the exhaust port 20 to the atmosphere B.

The chlorine-based solvent detoxification treatment apparatus 1 in the exhaust gas A of the present invention is as described above. Then, it becomes as follows.
(6) First, as described above, the exhaust gas A containing a chlorinated solvent and having a large flow rate of, for example, 1,000 m ³ / hr uses the adsorption / desorption of the chlorinated solvent by the adsorbent 9 through the adsorption / desorption tank 3. For example, the flow rate is adjusted to a small flow rate of 100 m ³ / hr, and then supplied to the plasma reactor 5. On the other hand, the exhaust gas A having a small flow rate is directly supplied to the plasma reactor 5.
Since the adsorption / desorption tank 3 is a system in which the adsorption / desorption tank 3 is adsorbed by the adsorbent 9, it is possible to treat the exhaust gas A having a large flow rate supplied over a long period of time. On the other hand, since the plasma reactor 5 is decomposed by plasma discharge, it is suitable for processing the exhaust gas A having a small flow rate that passes in units of seconds. And the process which matched each process aspect is implemented.
In this way, the harmless treatment apparatus 1 is a single unit, and can treat both a large flow rate exhaust gas A containing a chlorinated solvent and a small flow rate exhaust gas A.

(7) And in the detoxification treatment apparatus 1 of the present invention, the exhaust gas A having a large flow rate is adsorbed and removed in the adsorption / desorption tank 3 with certainty, so that the contained chlorine-based solvent is sufficiently cleaned. Exhaust gas A is released into the atmosphere B.
In addition, the small amount of the exhaust gas A and the small amount of the secondary exhaust gas A that has passed through the adsorption / desorption tank 3 are decomposed and removed by the plasma reactor 5 after the contained chlorine-based solvent is further left. The chlorinated solvent which has been decomposed and removed by the oxidation catalyst section 6 becomes exhaust gas A that is sufficiently cleaned, and is released into the atmosphere B.
In this way, the chlorinated solvent contained in the exhaust gas A is reliably removed, and the cleaned exhaust gas A is released into the atmosphere B.

(8) Furthermore, in the detoxification processing apparatus 1 of the present invention, a trapping sum tank 7 is provided after the plasma reactor 5.
And since the harmful product produced | generated with decomposition | disassembly of the chlorinated solvent in the plasma reactor 5 is neutralized or collected in the collection concentration sump tank 7, the exhaust gas fully cleaned also from this surface A is released into the atmosphere B.

(9) By the way, in the adsorption / desorption tank 3 of the detoxification treatment apparatus 1 of the present invention, the chlorine-based solvent contained in the exhaust gas A is first adsorbed by the activated carbon 12 which is the lower adsorbent 9, When the activated carbon 12 breaks through, it is adsorbed by the activated carbon 12 thereabove, and after that, the adsorption and breakthrough proceed from the bottom to the top.
Such adsorption and breakthrough, and the accompanying heat generation and heat release (that is, heat generation due to adsorption and heat release due to breakthrough) proceed sequentially from bottom to top. Then, by providing the temperature detection means 13 for each height level and detecting and monitoring the temperature change, it is possible to grasp the breakthrough progress of the activated carbon 12 in a timely manner.
Therefore, for example, the overall breakthrough of the activated carbon 12 in the adsorption / desorption tank 3 can be predicted in advance, and it is possible to prevent an accident in which the chlorinated solvent cannot be adsorbed due to oversight of the overall breakthrough.
In addition, when it is confirmed that the partial breakthrough of the partial height level is stopped, the activated carbon 12 can be used up without waste until the entire breakthrough occurs in the next use. Furthermore, in the case of the overall breakthrough, the activated carbon 12 is regenerated and reused or the activated carbon 12 is replaced by desorbing the chlorinated solvent by supplying hot air C.

(10) The detoxification processing apparatus 1 according to the present invention can employ the following processing method and operation method regardless of the processing method and operation method described above.
That is, even if the exhaust gas A has a small flow rate, during the day, the exhaust gas A is supplied from the supply port 2 to the adsorption / desorption tank 3 instead of the plasma reactor 5 to adsorb and remove the chlorinated solvent. Clean and release to atmosphere B.
Then, in the subsequent night power band, particularly in the late-night power band, the hot air supply unit 4 is driven to supply the hot air C to the adsorption / desorption tank 3 to desorb the chlorinated solvent and 2 supplied from the adsorption / desorption tank 3. The desorbed chlorine-based solvent in the next exhaust gas A is decomposed and removed by plasma discharge by driving the plasma reactor 5, thereby cleaning the exhaust gas A and releasing it into the atmosphere B.
When such a processing method and an operation method are implemented, the hot air supply unit 4 and the plasma reactor 5 are driven in the night power band, particularly in the late night power band, so that the electricity bill can be reduced accordingly.
Of course, even in the case of a large flow rate of exhaust gas A, in this way, a large flow rate of exhaust gas A is supplied to the adsorption / desorption tank 3 during the daytime, and adsorption is performed. Electricity costs can be reduced by a processing method and an operation method in which the hot air supply unit 4 and the plasma reactor 5 are driven in the midnight power band to perform desorption and decomposition.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory front view of the overall configuration of an apparatus for detoxifying a chlorinated solvent in exhaust gas according to the present invention for explaining the best mode for carrying out the invention. A plasma reactor is shown, (1) A figure is a side view, (2) A figure is a perspective view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Detoxification processing apparatus 2 Supply port 3 Adsorption / desorption tank 4 Hot-air supply part 5 Plasma reactor 6 Oxidation catalyst part 7 Collection concentration sum tank 8 Blower 9 Adsorbent 10 Outlet 11 Inlet 12 Activated carbon 13 Temperature detection means 14 Wire net 15 Central electrode 16 Dielectric 17 Outer electrode 18 Oxidation catalyst 19 Concentrated and concentrated solution 20 Outlet 21 Flow meter 22 Piping A Exhaust gas B Air C Hot air D Interval V Valve

Claims (5)

A detoxifying device for chlorine solvent contained in exhaust gas, equipped with a supply port, an adsorption / desorption tank, a hot air supply unit, a plasma reactor, etc.
The adsorption / desorption tank is filled with an adsorbent, and a large amount of exhaust gas containing a chlorinated solvent is supplied from the supply port to adsorb the chlorinated solvent to the adsorbent, thereby rendering it harmless. Exhaust gas can be discharged from its outlet to the atmosphere,
The hot air supply unit can supply hot air to the adsorption / desorption tank, and the hot air can desorb the chlorinated solvent adsorbed on the adsorbent in the adsorption / desorption tank,
The plasma reactor is supplied with a small flow rate of exhaust gas containing a chlorinated solvent from the supply port, or hot air gas containing a chlorinated solvent desorbed from the adsorbent in the adsorption / desorption tank, that is, a small amount of gas. A secondary exhaust gas having a flow rate is supplied, a chlorine-based solvent of the exhaust gas is decomposed by plasma discharge, and the detoxified exhaust gas can be discharged to the atmosphere. Detoxification equipment for chlorinated solvents in gas. In the detoxification processing apparatus for chlorinated solvents in exhaust gas according to claim 1, further comprising an oxidation catalyst part, a trapping sum tank,
The oxidation catalyst part is supplied with exhaust gas that has passed through the plasma reactor, and can decompose the remaining chlorinated solvent with the oxidation catalyst.
The trapping and summing tank is supplied with exhaust gas from the oxidation catalyst section, neutralizes and collects harmful product substances accompanying decomposition by the trapping and summing solution, and discharges the harmless exhaust gas to its outlet. A detoxifying device for chlorinated solvents in exhaust gas, characterized in that it can be released from the atmosphere into the atmosphere. 3. The apparatus for detoxifying a chlorinated solvent in exhaust gas according to claim 1 or 2, wherein the adsorption / desorption tank comprises an exhaust gas inlet provided at a lower end and an exhaust gas provided at an upper end. A discharge port, activated carbon filled inside as the adsorbent, and temperature detection means,
A plurality of the temperature detection means are provided according to the filling height level of the activated carbon, and as the activated carbon gradually adsorbs and breaks through the chlorinated solvent, Detecting the temperature change of heat generation and release of heat generation that gradually proceeds from bottom to top, and based on the detected temperature change, it is possible to always check the progress of breakthrough of the activated carbon A detoxifying device for chlorinated solvents in exhaust gas. In the detoxification processing apparatus for chlorinated solvent in exhaust gas according to claim 1, even if the exhaust gas has a small flow rate, the plasma is supplied from the supply port during the day regardless of the description in claim 1. Supplied to the adsorption / desorption tank, not the reactor,
In the nighttime power band, hot air is supplied from the hot air supply unit to the adsorption / desorption tank, and the secondary exhaust gas supplied from the adsorption / desorption tank is used to remove chlorine-based solvent by plasma discharge in the plasma reactor. An apparatus for detoxifying a chlorinated solvent in exhaust gas, wherein the exhaust gas that has been decomposed and rendered harmless can be released to the atmosphere.   2. The apparatus for detoxifying a chlorinated solvent in exhaust gas according to claim 1, wherein the hot air supply unit absorbs hot air having a temperature of about 1.88 times the boiling point of the chlorinated solvent at a small flow rate. An apparatus for detoxifying a chlorinated solvent in exhaust gas, characterized in that it can be supplied to a desorption tank.

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