JP6290320B2 - Exhaust gas treatment equipment, exhaust gas treatment method - Google Patents

Description

  The present invention relates to an exhaust gas treatment method for treating an exhaust gas containing a volatile organic compound, and an equipment for executing the method.

  Large quantities of organic solvents are used in industrial facilities that perform painting and printing. For this reason, the exhaust gas discharged from each factory contains volatile organic compounds (VOC) caused by organic solvents. When such VOC is released into the atmosphere without being treated, it becomes a causative substance of air pollution. Therefore, as a part of the measures concerning the release of VOCs, the governmental agencies obligate the industrial facilities as described above to process VOCs generated in the manufacturing process, and set regulations on the emission concentration. In response, each facility takes measures to reduce the VOC concentration in the exhaust gas prior to discharge. As a specific example of such a technique, for example, there is a processing apparatus described in Patent Document 1 below. This processing apparatus heats the exhaust gas and oxidizes and decomposes VOC in the exhaust gas to render it harmless.

JP 2011-94861 A

  By the way, in recent years, with the industrial development of emerging countries, the severity of air pollution is increasing in various parts of the world. As a result, VOC emission regulations by governments in each country are becoming stricter with each passing year. Therefore, in a specific country or region, it may be difficult to reduce the VOC concentration in the exhaust gas to less than the regulated value even if the processing apparatus described in Patent Document 1 is used. For this reason, it is required to further increase the treatment capacity of exhaust gas containing VOC.

  The present invention provides an exhaust gas treatment facility and an exhaust gas treatment method capable of enhancing the treatment capacity of a volatile organic compound (VOC) contained in exhaust gas.

According to the first aspect of the present invention, the exhaust gas treatment facility comprises:
A first exhaust gas treatment device having a combustion chamber that heats exhaust gas containing a volatile organic compound to oxidatively decompose the organic compound, and a first exhaust gas after the organic compound is oxidatively decomposed in the combustion chamber A second exhaust gas treatment device having a catalyst that oxidatively decomposes the organic compound remaining in the treatment gas; a second treatment gas that is an exhaust gas after the organic compound is oxidatively decomposed in the second exhaust gas treatment device; A preheating heat exchanger that exchanges heat with the exhaust gas before flowing into the first exhaust gas treatment device and heats the exhaust gas with the heat of the second treatment gas.
The first exhaust gas treatment device has a heat storage chamber that takes heat from the first process gas, temporarily stores the heat, and dissipates the stored heat to the exhaust gas before flowing into the combustion chamber. Have.
The exhaust gas treatment facility is configured to connect the first exhaust gas treatment device and the second exhaust gas treatment device so that the first treatment gas deprived of heat in the heat storage chamber is guided to the second exhaust gas treatment device. The first processing gas line is connected to the first processing gas line so that the first intermediate processing gas that is the exhaust gas in the combustion chamber is led to the second exhaust gas processing device. A first intermediate processing gas line, a temperature controller for detecting a temperature of exhaust gas flowing into the second exhaust gas processing device from the first processing gas line and the first intermediate processing gas line, and detection by the temperature controller A hot bypass valve that adjusts a flow rate of the first intermediate process gas flowing through the first intermediate process gas line according to the set temperature.
The temperature controller is provided in the first treatment gas line and on the second exhaust gas treatment device side of the connection position with the first intermediate treatment gas line. The hot bypass valve is provided in the first intermediate processing gas line.
The hot bypass valve adjusts the flow rate of the first intermediate processing gas flowing through the first intermediate processing gas line based on the temperature of the mixed gas detected by the temperature controller.

  In the exhaust gas treatment facility, the exhaust gas is heated by the first exhaust gas treatment device, and the organic compound (VOC) in the exhaust gas is oxidatively decomposed. Further, in the exhaust gas treatment facility, the VOC remaining in the first treatment gas discharged from the first exhaust gas treatment device is further oxidized and decomposed by the second exhaust gas treatment device. Therefore, in the exhaust gas treatment facility, VOCs in the exhaust gas can be treated to a higher degree than when the exhaust gas is treated with a single treatment device. That is, the VOC concentration in the exhaust gas can be greatly reduced.

  Further, in the exhaust gas treatment facility, the exhaust gas is heated by the heat of the second treatment gas before the exhaust gas flows into the first exhaust gas treatment device. Therefore, it is necessary to raise the temperature of the exhaust gas in the first exhaust gas treatment device. The amount of heat can be reduced, and as a result, the amount of fuel consumed can be reduced. Therefore, in the exhaust gas treatment facility, the running cost for the exhaust gas treatment can be suppressed.

  According to the second aspect of the present invention, in the exhaust gas treatment facility according to the first aspect, heat exchange is performed between the second process gas and the medium whose temperature has decreased due to heat radiation in the preheating heat exchanger, A waste heat recovery heat exchanger that heats the medium with the heat of the second processing gas is provided.

  In the exhaust gas treatment facility, the heat of the second process gas after passing through the preheating heat exchanger is recovered by the waste heat recovery heat exchanger, so that the heat of the second process gas can be effectively used.

  According to a third aspect of the present invention, in the exhaust gas treatment facility according to the first or second aspect, an exhaust gas having an increased organic compound concentration in a low concentration exhaust gas containing the organic compound is generated, and the exhaust gas A concentrating device for exhausting the air. The preheating heat exchanger exchanges heat between the exhaust gas exhausted from the concentrator and the second processing gas.

  In the exhaust gas treatment facility, the amount of exhaust gas treated by the first exhaust gas treatment device and the second exhaust gas treatment device can be reduced when treating low concentration exhaust gas. For this reason, size reduction of a 1st exhaust gas processing apparatus and a 2nd exhaust gas processing apparatus can be achieved, and installation cost can be held down. Furthermore, in the exhaust gas treatment facility, the exhaust gas treated by the first exhaust gas treatment device and the second exhaust gas treatment device can be increased in concentration, so that the running cost can be suppressed.

  In the exhaust gas treatment facility, the first intermediate treatment gas, which is a high-temperature exhaust gas in the combustion chamber, is joined to the first treatment gas that has been deprived of heat in the heat storage chamber, and then this mixed gas is used as the second exhaust gas treatment device. To flow into. For this reason, in the exhaust gas treatment facility, the temperature of the exhaust gas flowing into the second exhaust gas treatment device can be within the activation temperature range of the catalyst without burning the fuel or the like and heating the first treatment gas. Therefore, in this exhaust gas treatment facility, the running cost for exhaust gas treatment can also be suppressed from this viewpoint.

  According to a sixth aspect of the present invention, in the exhaust gas treatment facility according to any one of the first aspect to the fifth aspect, the second exhaust gas treatment device includes a gas inlet and a gas outlet. A casing, the catalyst disposed in the casing, and a pretreatment portion disposed in the casing and closer to the gas inlet than the catalyst. The pretreatment unit is included in the exhaust gas flowing into the second exhaust gas treatment device, and removes a causative substance that degrades the performance of the catalyst.

  In the exhaust gas treatment facility, deterioration in catalyst performance can be suppressed.

According to another aspect of the present invention, the exhaust gas treatment facility comprises:
A combustion chamber that heats exhaust gas containing a volatile organic compound to oxidatively decompose the organic compound, and heat from the first processing gas that is exhaust gas after the organic compound is oxidized and decomposed in the combustion chamber A second exhaust gas treatment device having a heat storage chamber for giving to the exhaust gas before flowing into the combustion chamber; and a second catalyst having a catalyst for oxidizing and decomposing the organic compound remaining in the gas exhausted from the first exhaust gas treatment device. The first gas treatment device and the second gas treatment device are connected so that the exhaust gas treatment device and the first treatment gas after the heat is taken away in the transmission chamber are guided to the second gas treatment device. The first processing gas line and the combustion chamber of the first gas processing device and the first processing gas line so that the first intermediate processing gas that is the gas in the combustion chamber is led to the second gas processing device. First intermediate to connect A temperature controller for detecting a temperature of a gas flowing into the second gas processing apparatus from the first processing gas line and the first intermediate processing gas line, and a temperature detected by the temperature controller. And a hot bypass valve for adjusting a flow rate of the first intermediate process gas flowing through the first intermediate process gas line.

According to the seventh aspect of the present invention, the exhaust gas treatment method comprises:
A first exhaust gas treatment step including an oxidation treatment step in which exhaust gas containing a volatile organic compound is heated to oxidatively decompose the organic compound; and after the organic compound in the exhaust gas is oxidatively decomposed in the oxidation treatment step A second exhaust gas treatment step including a second oxidation treatment step of oxidizing and decomposing the organic compound remaining in the first treatment gas which is an exhaust gas of the catalyst, and after the organic compound is oxidatively decomposed in the second exhaust gas treatment step Heat exchange between the second processing gas that is the exhaust gas of the gas and the exhaust gas before passing through the first exhaust gas processing step, and a preheating step that heats the exhaust gas while cooling the second processing gas. .
The first exhaust gas treatment step takes heat from the first treatment gas, temporarily stores the heat, and stores heat to release the stored heat to the exhaust gas before the oxidation treatment step is performed. / Includes heat dissipation process.
The mixing step of mixing the first intermediate processing gas, which is the exhaust gas in the oxidation processing step, with the first processing gas, which has been deprived of heat in the heat storage / radiation step and before the second exhaust gas processing step, is performed. .
In the second exhaust gas treatment step, the organic compound in the mixed gas, which is an exhaust gas in which the first treatment gas and the first intermediate treatment gas are mixed, is oxidatively decomposed.
The mixing step adjusts the flow rate of the first intermediate processing gas to be mixed with the first processing gas according to the temperature detection step of detecting the temperature of the mixed gas and the temperature detected in the temperature detection step. A flow rate adjusting step is included.

  According to an eighth aspect of the present invention, in the exhaust gas processing method according to the seventh aspect, the second processing gas cooled in the preheating step and the medium are subjected to heat exchange, and the second processing gas is A waste heat recovery process for heating the medium while cooling is performed.

  According to a ninth aspect of the present invention, in the exhaust gas treatment method according to either the seventh aspect or the eighth aspect, an exhaust gas having an increased concentration of an organic compound in a low-concentration exhaust gas containing the organic compound is provided. A concentration step of generating and exhausting the exhaust gas is performed. In the preheating step, heat exchange is performed between the exhaust gas exhausted in the concentration step and the second processing gas.

According to a twelfth aspect of the present invention,
In the exhaust gas treatment method according to any one of the seventh to eleventh aspects, the second exhaust gas treatment step further includes a pretreatment step of pretreating the exhaust gas before passing through the second dioxide treatment step. Including. In the pretreatment step, a causative substance that is contained in the exhaust gas before passing through the second oxidation treatment step and reduces the performance of the catalyst is removed.

  According to the exhaust gas processing apparatus and the exhaust gas processing method according to the aspect of the present invention, VOC contained in the exhaust gas can be processed at a high level. That is, the VOC concentration in the exhaust gas can be greatly reduced.

  Moreover, according to the exhaust gas processing apparatus and the exhaust gas processing method according to the aspect of the present invention, the exhaust gas is heated before the exhaust gas flows in. For this reason, the amount of heat required to raise the temperature of the exhaust gas can be reduced, and as a result, the consumption of fuel and the like can be suppressed. Therefore, the running cost concerning exhaust gas treatment can be suppressed.

It is a systematic diagram of the exhaust gas treatment facility in the first embodiment according to the present invention. It is a flowchart which shows the procedure of the waste gas processing method in 1st embodiment which concerns on this invention. It is a systematic diagram of the exhaust gas treatment facility in the second embodiment according to the present invention. It is a flowchart which shows the procedure of the waste gas processing method in 2nd embodiment which concerns on this invention.

  Hereinafter, various embodiments of an exhaust gas treatment facility according to the present invention will be described with reference to the drawings.

"First embodiment"
A first embodiment of an exhaust gas treatment facility according to the present invention will be described with reference to FIGS. 1 and 2.

  The exhaust gas treatment facility of this embodiment is a facility for treating the exhaust gas G0 containing VOC. As shown in FIG. 1, the exhaust gas treatment facility includes a first exhaust gas treatment device 10 that heats the exhaust gas G0 to oxidatively decompose VOC in the exhaust gas G0, and a second exhaust gas treatment that oxidizes and decomposes VOC using the catalyst 36. The apparatus 30 and the preheating heat exchanger 55 which heats the waste gas G0 which flows into the 1st waste gas processing apparatus 10 are provided.

  The first exhaust gas treatment device 10 includes a casing 11, a burner 21, and a rotary distribution valve 23. In the casing 11, a combustion chamber 15, a heat storage chamber 17, and an entry / exit chamber 12 are formed. The combustion chamber 15 is a chamber for heating the exhaust gas G0 to oxidatively decompose VOC in the exhaust gas G0. The heat storage chamber 17 takes heat from the first exhaust gas G1 which is exhaust gas after the exhaust gas G0 is oxidatively decomposed in the combustion chamber 15, stores this heat temporarily, and releases the stored heat to the exhaust gas G0. It is a room. The entry / exit chamber 12 is a chamber through which the exhaust gas G0 flows from the outside and the first processing gas G1 flows out. The heat storage chamber 17 is formed between the combustion chamber 15 and the entrance / exit chamber 12 in the casing 11. A gas inlet 13 and a gas outlet 14 are formed in a portion of the casing 11 and defined by the inlet / outlet chamber 12. In the heat storage chamber 17, a plurality of heat storage passages 18 are formed to connect the combustion chamber 15 and the inlet / outlet chamber 12. The plurality of heat storage passages 18 are formed of a heat storage body such as ceramic, for example. An intermediate processing gas outlet 16 through which the first intermediate processing gas G1i, which is the exhaust gas in the combustion chamber 15, flows out to the outside, is formed in a portion of the casing 11 that defines the combustion chamber 15.

  The burner 21 is provided in a portion of the casing 11 that defines the combustion chamber 15. The burner 21 receives fuel from the outside, mixes this fuel with air outside the combustion chamber 15 and burns it, forms a flame in the combustion chamber 15, and heats the exhaust gas G 0 flowing into the combustion chamber 15. To do. That is, the burner 21 functions as a heater for heating the exhaust gas G0 flowing into the combustion chamber 15.

  A rotation distribution valve 23 is disposed in the entrance / exit chamber 12. In the rotary distribution valve 23, the same number of distribution channels 25 as the plurality of heat storage channels 18 formed in the heat storage chamber 17 are formed. In a state in which the rotary distribution valve 23 is stationary, each of the plurality of distribution channels 25 communicates with one of the plurality of heat storage channels 18 formed in the heat storage chamber 17.

  The exhaust gas G0 that has flowed into the inlet / outlet chamber 12 from the gas inlet 13 of the casing 11 passes through a part of the plurality of distribution channels 25 formed in the rotary distribution valve 23, and a part of the heat storage chamber 17. Into the heat storage flow path 18. The exhaust gas G0 that has flowed into a part of the heat storage passage 18 of the heat storage chamber 17 flows into the combustion chamber 15 through this part of the heat storage passage 18. The exhaust gas in the combustion chamber 15 flows into another part of the heat storage passage 18 of the heat storage chamber 17. This exhaust gas passes through the other part of the heat storage passage 18 as the first processing gas G1 described above, and the other part of the plurality of distribution passages 25 formed in the rotary distribution valve 23. 25. The first processing gas G1 that has flowed into the other part of the distribution flow path 25 flows out from the gas outlet 14 to the outside. The heat of the first processing gas G1 is stored in the heat storage body forming the heat storage flow path 18.

  When the rotary distribution valve 23 rotates, among the plurality of heat storage channels 18 in the heat storage chamber 17, the heat storage channel 18 through which the exhaust gas G0 flows is switched to another heat storage channel 18, and the heat storage channel through which the first processing gas G1 flows. 18 switches to another heat storage flow path 18. As a result, the exhaust gas G0 flows into the heat storage channel 18 in which the first processing gas G1 has previously flowed out of the plurality of heat storage channels 18 in the heat storage chamber 17. For this reason, the heat previously stored in the heat accumulator by flowing the first processing gas G1 is radiated to the exhaust gas G0. That is, in the heat storage chamber 17, the exhaust gas G0 is heated and the first processing gas G1 is cooled.

  As described above, when the rotary distribution valve 23 rotates, among the plurality of heat storage channels 18 in the heat storage chamber 17, the heat storage channel 18 through which the exhaust gas G0 flows and the heat storage channel 18 through which the first processing gas G1 flows are sequentially switched. In the heat storage body forming the plurality of heat storage flow paths 18 of the heat storage chamber 17, the region for storing heat and the region for radiating heat move sequentially.

  As described above, in the first exhaust gas treatment device 10, the exhaust gas G0 is heated to oxidize and decompose the VOC in the exhaust gas G0, and the heat in the first treatment gas G1 generated by the heating of the exhaust gas G0 is primary. The heat is stored in the heat storage body and this heat is used for heating the exhaust gas G0. The first exhaust gas treatment device 10 may have any configuration as long as it has a function of heating the exhaust gas G0.

  The second exhaust gas treatment device 30 includes a casing 31, a catalyst 36 disposed in the casing 31, and a pretreatment unit 35 disposed in the casing 31. A gas inlet 33 and a gas outlet 34 are formed in the casing 31.

The catalyst 36 is made of, for example, platinum or palladium. The catalyst 36 has a function of promoting the decomposition reaction of VOC at the activation temperature. This decomposition reaction of VOC is accompanied by oxidation reaction of VOC. That is, the catalyst 36 oxidizes and decomposes VOC and promotes a reaction to convert this VOC into CO ₂ and H ₂ O. The activation temperature of the catalyst 36 is, for example, 200 to 380 ° C.

  The exhaust gas flowing in from the gas inlet 33 of the second exhaust gas treatment device 30 may contain a causative substance that lowers the catalyst performance, that is, catalyst poison. Examples of such causative substances include dust, carbon, tar, organometallic compounds, and organosilicon compounds. Any of these causative substances adheres to the surface of the catalyst 36 and lowers the function of the catalyst 36. The preprocessing unit 35 has a function of removing such causative substances. Therefore, the pretreatment unit 35 is disposed in the casing 31 and closer to the gas inlet 33 than the catalyst 36. The pretreatment unit 35 includes a pretreatment agent formed using alumina, manganese oxide, or the like as a base material, or a filter that captures dust or the like. The activation temperature of the pretreatment agent is, for example, 350 to 400 ° C. The pretreatment unit 35 may have a pretreatment agent and a filter.

The exhaust gas treatment facility of the present embodiment further includes an exhaust gas line 45, a first process gas line 41, a first intermediate process gas line 42, a temperature controller 43, a hot bypass valve 44, and a second process gas line. 46 and an intake port 47.
The exhaust gas line 45 is connected to the gas inlet 13 of the first exhaust gas treatment device 10. The exhaust gas line 45 guides the exhaust gas G0 into the first exhaust gas treatment device 10. The exhaust gas line 45 is provided with an exhaust gas fan 59 that forms a flow of the exhaust gas G0 as necessary. The exhaust gas line 45 is provided with an intake port 47 as necessary. The intake port 47 introduces outside air into the exhaust gas line 45 when the exhaust gas treatment apparatus according to the present embodiment is activated or in an emergency.
The first treatment gas line 41 connects the gas outlet 14 of the first exhaust gas treatment device 10 and the gas inlet 33 of the second exhaust gas treatment device 30. The first processing gas line 41 guides the first processing gas G <b> 1 after the heat is removed from the heat storage chamber 17 of the first exhaust gas processing device 10 to the second exhaust gas processing device 30. The first intermediate processing gas line 42 connects the intermediate processing gas outlet 16 of the first exhaust gas processing apparatus 10 and the first processing gas line 41. The first intermediate processing gas line 42 guides the first intermediate processing gas G1i that is the exhaust gas in the combustion chamber 15 of the first exhaust gas processing device 10 to the second exhaust gas processing device 30. The temperature controller 43 is provided in the first process gas line 41 and closer to the second exhaust gas treatment device 30 than the connection position with the first intermediate process gas line 42. Therefore, the temperature controller 43 is a mixture gas Gm in which the first processing gas G1 flowing through the first processing gas line 41 and the first intermediate processing gas G1i flowing through the first intermediate processing gas line 42 are mixed. Detect temperature.
The hot bypass valve 44 is provided in the first intermediate processing gas line 42. The hot bypass valve 44 adjusts the flow rate of the first intermediate processing gas G1i flowing through the first intermediate processing gas line 42 based on the temperature detected by the temperature controller 43.

  The second processing gas line 46 is connected to the gas outlet 34 of the second exhaust gas processing device 30. The preheating heat exchanger 55 is a heat exchanger provided across the second processing gas line 46 and the exhaust gas line 45. The preheating heat exchanger 55 heat-exchanges the exhaust gas G0 flowing through the exhaust gas line 45 and the second processing gas G2 flowing through the second processing gas line 46 to cool the second processing gas G2 while heating the exhaust gas G0. To do.

  Next, according to the flowchart shown in FIG. 2, the procedure of the exhaust gas treatment in the exhaust gas treatment facility according to the present embodiment will be described.

  As described above, the exhaust gas G0 flowing through the exhaust gas line 45 is heat-exchanged with the second processing gas G2 in the preheating heat exchanger 55 and heated (S11: preheating step). The temperature of the second process gas G2 immediately after flowing out of the second exhaust gas treatment device 30 is, for example, 355 ° C. The temperature of the exhaust gas G0 before being heated by the preheating heat exchanger 55 is, for example, 60 ° C. The temperature of the exhaust gas G0 after being heated by the preheating heat exchanger 55 is 160 ° C., for example.

The exhaust gas G0 heated by the preheating heat exchanger 55 flows into the casing 11 from the gas inlet 13 of the first exhaust gas treatment device 10. The exhaust gas G0 flows into the combustion chamber 15 through a part of the heat storage channels 18 of the plurality of heat storage channels 18 of the heat storage chamber 17. As described above, the exhaust gas G0 is heated by the heat stored in the heat storage body forming the heat storage flow path 18 in the process of flowing through the heat storage flow path 18 of the heat storage chamber 17 (S2: heat storage / heat radiation process). The exhaust gas G0 heated by the heat storage body is further heated in the combustion chamber 15, and most VOCs in the exhaust gas G0 are oxidatively decomposed (S3: oxidative decomposition step). By this oxidative decomposition step (S3), most of the VOC in the exhaust gas G0 becomes CO ₂ and H ₂ O, and is detoxified. Most of the exhaust gas in the combustion chamber 15 flows into the other part of the heat storage channels 18 among the plurality of heat storage channels 18 of the heat storage chamber 17 as the first processing gas G1, Flowing. The temperature of the exhaust gas immediately before flowing into the heat storage chamber 17 from the combustion chamber 15 is, for example, 850 ° C. As described above, in the process of flowing through the heat storage flow path 18 of the heat storage chamber 17, the first process gas G1 is deprived of heat by the heat storage body forming the heat storage flow path 18 and cooled (S2: heat storage / heat radiation process). ).

  The first processing gas G <b> 1 cooled in the process of flowing through the heat storage flow path 18 flows out from the gas outlet 14 of the first exhaust gas processing apparatus 10 and flows through the first processing gas line 41. The temperature of the first process gas G1 immediately after flowing out of the first exhaust gas treatment device 10 is, for example, 200 ° C. In the first exhaust gas treatment apparatus 10, the first exhaust gas treatment step (S1) including the heat storage / heat release step (S2) and the oxidative decomposition step (S3) described above is performed.

  Part of the exhaust gas in the combustion chamber 15 of the first exhaust gas treatment device 10 flows out from the intermediate treatment gas outlet 16 of the first exhaust gas treatment device 10 as the first intermediate treatment gas G1i, and passes through the first intermediate treatment gas line 42. Flowing. The first intermediate processing gas G1i flows from the first intermediate processing gas line 42 into the first processing gas line 41 and joins the first processing gas G1 (S4: mixing step). The temperature of the first intermediate processing gas G1i is, for example, 850 ° C. The mixed gas Gm, which is an exhaust gas in which the first processing gas G1 and the first intermediate processing gas G1i are merged, passes through the first processing gas line 41 and from the gas inlet 33 of the second exhaust gas processing device 30 to the second exhaust gas processing device 30. Flows in. In this mixing step (S4), the temperature of the mixed gas Gm is detected by the temperature controller 43 (S5: temperature detection step). The hot bypass valve 44 provided in the first intermediate processing gas line 42 is configured to supply the first intermediate processing gas G1i flowing through the first intermediate processing gas line 42 based on the temperature of the mixed gas Gm detected by the temperature controller 43. The flow rate is adjusted (S6: flow rate adjusting step).

  The activation temperature of the catalyst 36 of the second exhaust gas treatment device 30 is, for example, 200 to 380 ° C. as described above. Further, the temperature of the first process gas G1 immediately after flowing out of the first exhaust gas treatment apparatus 10 is, for example, 180 ° C. as described above. For this reason, in the flow rate adjusting step (S6), the flow rate of the first intermediate processing gas G1i at 850 ° C. mixed in the first processing gas G1 at 180 ° C. is adjusted so that the temperature of the mixed gas Gm becomes 280-380 ° C. To do. For example, when a pretreatment agent having an activation temperature of 350 to 400 ° C. is used as the pretreatment unit 35 of the second exhaust gas treatment apparatus 30, the temperature of the mixed gas Gm is 350 to 400 ° C. in the flow rate adjustment step (S 6). The flow rate of the first intermediate processing gas G1i mixed in the first processing gas G1 is adjusted so that 350 to 400 ° C. is a temperature range in which both the catalyst 36 and the pretreatment agent are at the activation temperature.

The mixed gas Gm that has flowed into the second exhaust gas treatment device 30 first passes through the pretreatment unit 35. In the course of passing through the pretreatment section 35, the mixed gas Gm is removed from the mixed gas Gm by a causative substance that lowers the catalyst performance in the mixed gas Gm (S8: pretreatment step). The mixed gas Gm that has passed through the pretreatment section 35 then passes through the catalyst 36. In the process of passing through the catalyst 36, the mixed gas Gm oxidizes and decomposes VOC remaining in the mixed gas Gm to become CO ₂ and H ₂ O (S9: oxidative decomposition step).

  The exhaust gas that has passed through the catalyst 36 flows out from the gas outlet 34 of the second exhaust gas processing device 30 as the second processing gas G2, and flows into the second processing gas line 46. In the second exhaust gas treatment device 30, the second treatment step (S7) including the pretreatment step (S8) and the oxidative decomposition step (S9) described above is performed.

  As described above, the second process gas G2 flowing through the second process gas line 46 is heat-exchanged with the exhaust gas G0 flowing through the exhaust gas line 45 in the preheating heat exchanger 55 and cooled (S11: preheating step). The temperature of the second process gas G2 immediately after flowing out of the second exhaust gas treatment device 30 is, for example, 355 ° C. The temperature of the second processing gas G2 after being cooled by the preheating heat exchanger 55 is, for example, 250 ° C.

  As described above, in this embodiment, after the VOC in the exhaust gas G0 is oxidatively decomposed by the first exhaust gas treatment apparatus 10, the VOC remaining in the first process gas G1 that has passed through the first exhaust gas treatment apparatus 10 is secondly converted. Further oxidative decomposition is performed by the exhaust gas treatment device 30. Therefore, in this embodiment, the concentration of VOC in the exhaust gas G0 can be significantly reduced as compared with the case where the VOC in the exhaust gas G0 is processed by a single processing device. That is, in this embodiment, the processing capacity of VOC contained in the exhaust gas G0 can be significantly increased.

  Further, in the present embodiment, the exhaust gas G0 is heated by the heat of the second processing gas G2 in the preheating heat exchanger 55 before the exhaust gas G0 flows into the first exhaust gas treatment device 10, so that the exhaust gas G0 that has flowed into the combustion chamber 15 is The flow rate of fuel or the like necessary for heating can be suppressed. In the present embodiment, the first intermediate processing gas G1i that is the high-temperature exhaust gas in the combustion chamber 15 is joined to the first processing gas G1 that has been deprived of heat in the heat storage chamber 17, and then this mixed gas. Gm is allowed to flow into the second exhaust gas treatment device 30. For this reason, in this embodiment, the temperature of the exhaust gas flowing into the second exhaust gas treatment device 30 can be within the activation temperature range of the catalyst 36 without burning the fuel or the like and heating the first treatment gas G1. . Therefore, in this embodiment, the running cost concerning exhaust gas treatment can be suppressed.

"Second embodiment"
A second embodiment of the exhaust gas treatment facility according to the present invention will be described with reference to FIGS. 3 and 4.

  As shown in FIG. 3, the exhaust gas treatment facility of the present embodiment is a facility in which a concentrator 50 and a waste heat recovery heat exchanger 56 are added to the exhaust gas treatment facility of the first embodiment.

  In the exhaust gas treatment facility of the present embodiment, the low concentration exhaust gas GL having a VOC concentration lower than that of the exhaust gas G0 treated in the exhaust gas treatment facility of the first embodiment is processed. The concentrator 50 concentrates the low-concentration exhaust gas GL into exhaust gas having a high concentration and a low air volume. The concentrating device 50 has a rotating cylindrical rotor, an adsorbent supported on the surface of the rotor, and a casing that covers the rotor. The adsorbent is, for example, zeolite and adsorbs VOC. Within the casing are an adsorption zone, a regeneration zone, and a cooling zone. Hot air passes through the regeneration zone in the casing. Of the adsorbents supported on the rotor surface, the adsorbent located in the adsorption zone adsorbs VOC in the low-concentration exhaust gas GL. The adsorbent that is located in the adsorption zone and has adsorbed the VOC causes the VOC to be released in the small amount of hot air when the adsorbent that has adsorbed the VOC is located in the regeneration zone by the rotation of the rotor. Thereby, the exhaust gas of the small air volume which raised the VOC density | concentration in the low concentration exhaust gas GL is produced | generated.

  The concentrating device 50 discharges the exhaust gas having an increased VOC concentration as the exhaust gas G0. The gas outlet 54 of the concentrator 50 and the gas inlet 13 of the first exhaust gas treatment device 10 are connected by an exhaust gas line 45. The exhaust gas line 45 is provided with an exhaust gas fan 59 that forms a flow of the exhaust gas G0 flowing through the exhaust gas line 45 as necessary.

  The preheating heat exchanger 55 is provided across the second process gas line 46 and the exhaust gas line 45 as in the first embodiment. The waste heat recovery heat exchanger 56 is disposed in the second processing gas line 46 and downstream of the preheating heat exchanger 55 in the flow of the second processing gas G2. The waste heat recovery heat exchanger 56 is a heat exchanger that exchanges heat between the second processing gas G2 flowing through the second processing gas line 46 and the outside air A, and cools the second processing gas G2, while Heat. The waste heat recovery heat exchanger 56 exchanges heat between the outside air A and the second processing gas G2, but may exchange heat between a medium other than the outside air A and the second treatment gas G2.

  Next, the procedure of the exhaust gas treatment in the exhaust gas treatment facility according to the present embodiment will be described according to the flowchart shown in FIG.

  As described above, the concentrating device 50 changes the low-concentration exhaust gas GL into an exhaust gas G0 having a small air volume and a high VOC concentration, and then discharges the exhaust gas G0. That is, the concentration apparatus 50 concentrates VOC in the low concentration exhaust gas GL (S10: concentration step). Here, the temperature of the exhaust gas G0 immediately after flowing out of the concentrator 50 is, for example, 60 ° C. As described above, the exhaust gas G0 is heat-exchanged with the second processing gas G2 in the preheating heat exchanger 55 (S11: preheating step). The temperature of the second process gas G2 immediately after flowing out of the second exhaust gas treatment device 30 is, for example, 355 ° C. The second process gas G2 is cooled by heat exchange between the second process gas G2 and the exhaust gas G0, and the exhaust gas G0 is heated. The temperature of the exhaust gas G0 preheated by heat exchange with the second processing gas G2 is, for example, 160 ° C.

  The exhaust gas G0 preheated by the preheating heat exchanger 55 passes through the first exhaust gas treatment device 10 and the second exhaust gas treatment device 30 as in the first embodiment. For this reason, in the facility including the first exhaust gas treatment device 10 and the second exhaust gas treatment device 30, as in the first embodiment, the first exhaust gas treatment step (S1), the mixing step (S4), and the second exhaust gas treatment step ( S7) is executed.

  The second processing gas G <b> 2 from the second exhaust gas processing device 30 flows into the preheating heat exchanger 55 through the second processing gas line 46. As described above, the second processing gas G2 is cooled by heat exchange with the exhaust gas G0 in the process of flowing through the preheating heat exchanger 55 (S11: preheating step). The temperature of the second processing gas G2 after being cooled by the preheating heat exchanger 55 is, for example, 250 ° C. as in the first embodiment.

  The second processing gas G <b> 2 that has passed through the preheating heat exchanger 55 flows into the waste heat recovery heat exchanger 56. In the waste heat recovery heat exchanger 56, the medium such as the outside air A and the second process gas G2 are heat-exchanged, and the outside process A is heated while the second process gas G2 is cooled (S12: waste heat). Recovery process).

  As described above, in this embodiment, the low-concentration exhaust gas GL is converted into the exhaust gas G0 having a small air volume and a high VOC concentration, and then the exhaust gas G0 is processed by the first exhaust gas treatment device 10 and the second exhaust gas treatment device 30. Therefore, in this embodiment, when processing the low-concentration exhaust gas GL, the amount of exhaust gas to be processed by the first exhaust gas processing device 10 and the second exhaust gas processing device 30 can be reduced. The two exhaust gas treatment devices 30 can be downsized, and the equipment cost can be reduced. Furthermore, in this embodiment, since the amount of exhaust gas processed by the first exhaust gas treatment device 10 and the second exhaust gas treatment device 30 can be increased, the running cost can also be suppressed.

  Moreover, in this embodiment, since the heat | fever of the 2nd process gas G2 after passing the preheating heat exchanger 55 is collect | recovered with the waste-heat recovery heat exchanger 56, using this heat | fever of the 2nd process gas G2 effectively. Can do.

  In addition, this embodiment is the installation which added the concentrating apparatus 50 and the waste heat recovery heat exchanger 56 to the waste gas treatment facility of 1st embodiment as mentioned above. However, only one of the concentrator 50 and the waste heat recovery heat exchanger 56 may be added to the exhaust gas treatment facility of the first embodiment.

DESCRIPTION OF SYMBOLS 10 1st exhaust gas processing apparatus 11 Casing 12 Entrance / exit chamber 13 Gas inlet 14 Gas outlet 15 Combustion chamber 16 Intermediate processing gas outlet 17 Thermal storage chamber 18 Thermal storage flow path 21 Burner 23 Rotary distribution valve 25 Distribution flow path 30 Second exhaust gas processing apparatus 31 Casing 33 Gas inlet 34 Gas outlet 35 Pretreatment section 36 Catalyst 41 First treatment gas line 42 First intermediate treatment gas line 43 Temperature controller 44 Hot bypass valve 45 Exhaust gas line 46 Second treatment gas line 47 Inlet 50 Concentrator 54 Gas Outlet 55 Preheat heat exchanger 56 Waste heat recovery heat exchanger 59 Exhaust gas fan G0 Exhaust gas G1 First process gas G1i First intermediate process gas Gm Mixed gas G2 Second process gas GL Low concentration exhaust gas

Claims (8)

A first exhaust gas treatment device having a combustion chamber that heats exhaust gas containing a volatile organic compound to oxidatively decompose the organic compound;
A second exhaust gas treatment device having a catalyst that oxidatively decomposes the organic compound remaining in the first treatment gas, which is exhaust gas after the organic compound is oxidatively decomposed in the combustion chamber;
Heat exchange between the second processing gas, which is the exhaust gas after the organic compound has been oxidatively decomposed in the second exhaust gas processing device, and the exhaust gas before flowing into the first exhaust gas processing device; A preheating heat exchanger for heating the exhaust gas by the heat of
Equipped with a,
The first exhaust gas treatment device has a heat storage chamber that takes heat from the first process gas, temporarily stores the heat, and dissipates the stored heat to the exhaust gas before flowing into the combustion chamber. Have
A first treatment gas line connecting the first exhaust gas treatment device and the second exhaust gas treatment device so that the first treatment gas deprived of heat in the heat storage chamber is guided to the second exhaust gas treatment device;
A first intermediate processing gas that connects the combustion chamber of the first exhaust gas processing device and the first processing gas line so that the first intermediate processing gas that is the exhaust gas in the combustion chamber is guided to the second exhaust gas processing device. Line,
A temperature controller for detecting the temperature of the exhaust gas flowing into the second exhaust gas treatment device from the first process gas line and the first intermediate process gas line;
A hot bypass valve that adjusts the flow rate of the first intermediate processing gas flowing through the first intermediate processing gas line in accordance with the temperature detected by the temperature controller;
Further comprising
The temperature controller is in the first processing gas line, and is provided on the second exhaust gas treatment device side from the connection position with the first intermediate processing gas line,
The hot bypass valve is provided in the first intermediate processing gas line,
The hot bypass valve is an exhaust gas treatment facility that adjusts the flow rate of the first intermediate process gas flowing through the first intermediate process gas line based on the temperature of the mixed gas detected by the temperature controller . In the exhaust gas treatment facility according to claim 1,
A waste heat recovery heat exchanger that heat-exchanges the second processing gas and the medium whose temperature has been reduced by heat radiation in the preheating heat exchanger, and heats the medium by the heat of the second processing gas;
Exhaust gas treatment equipment. The exhaust gas treatment facility according to claim 2,
Further comprising a concentrating device for generating exhaust gas having an increased organic compound concentration in the low-concentration exhaust gas containing the organic compound and exhausting the exhaust gas;
The preheating heat exchanger exchanges heat between the exhaust gas exhausted from the concentrator and the second processing gas.
Exhaust gas treatment equipment. In the exhaust gas treatment facility according to any one of claims 1 to 3 ,
The second exhaust gas treatment device includes a casing in which a gas inlet and a gas outlet are formed, the catalyst arranged in the casing, and the gas inside the casing and closer to the gas inlet than the catalyst. A pre-processing unit,
The pretreatment unit is included in the exhaust gas flowing into the second exhaust gas treatment device, and removes a causative substance that reduces the performance of the catalyst.
Exhaust gas treatment equipment. A first exhaust gas treatment step including an oxidation treatment step in which an exhaust gas containing a volatile organic compound is heated to oxidatively decompose the organic compound;
A second exhaust gas treatment step including a second dioxide treatment step of oxidizing and decomposing the organic compound remaining in the first treatment gas, which is an exhaust gas after the organic compound in the exhaust gas is oxidatively decomposed in the oxidation treatment step, with a catalyst; When,
The second treatment gas, which is the exhaust gas after the organic compound is oxidized and decomposed in the second exhaust gas treatment step, is heat-exchanged with the exhaust gas before the first exhaust gas treatment step, and the second treatment gas is A preheating step of heating the exhaust gas while cooling;
Run
The first exhaust gas treatment step takes heat from the first treatment gas, temporarily stores the heat, and stores heat to release the stored heat to the exhaust gas before the oxidation treatment step is performed. / Including heat dissipation process,
The mixing step of mixing the first intermediate processing gas, which is the exhaust gas in the oxidation processing step, with the first processing gas before being subjected to the second exhaust gas processing step is deprived of heat in the heat storage / radiation step. ,
In the second exhaust gas treatment step, the organic compound in the mixed gas which is an exhaust gas in which the first treatment gas and the first intermediate treatment gas are mixed is oxidized and decomposed,
The mixing step adjusts the flow rate of the first intermediate processing gas to be mixed with the first processing gas according to the temperature detection step of detecting the temperature of the mixed gas and the temperature detected in the temperature detection step. Including a flow control step,
Exhaust gas treatment method.   The exhaust gas treatment method according to claim 5,
  Heat exchange between the second processing gas and the medium cooled in the preheating step, and performing a waste heat recovery step of heating the medium while cooling the second processing gas;
  Exhaust gas treatment method.   In the exhaust gas treatment method according to claim 5 or 6,
  Generating an exhaust gas having an increased concentration of organic compounds in the low-concentration exhaust gas containing the organic compound, and executing a concentration step of exhausting the exhaust gas;
  In the preheating step, heat exchange is performed between the exhaust gas exhausted in the concentration step and the second processing gas.
  Exhaust gas treatment method.   In the exhaust gas treatment method according to any one of claims 5 to 7,
  The second exhaust gas treatment step further includes a pretreatment step of pretreating the exhaust gas before passing through the second dioxide treatment step,
  In the pretreatment step, a causative substance that is contained in the exhaust gas before passing through the second oxidation treatment step and reduces the performance of the catalyst is removed.
  Exhaust gas treatment method.

Images