Exhaust gas treatment system, exhaust gas treatment method, and method for retrofitting an exhaust gas treatment system

Abstract

The exhaust gas treatment system 10 includes an exhaust gas separation device 11 that receives a first gas 22a containing a specific substance, separates a part of the specific substance contained in the first gas 22a, and discharges a second gas 22b having a lower content of the specific substance than the first gas 22a; a decontamination device 12 that treats the second gas 22b to solubilize the specific substance, dissolves the solubilized specific substance in supply water, and discharges a first wastewater 23a; and a wastewater treatment facility 13 that receives the first wastewater 23a, removes the specific substance from the first wastewater 23a, and recovers the wastewater from which the specific substance has been removed as makeup water for supply water.

Description

Technical Field

[0001] The present invention relates to an exhaust gas treatment system, an exhaust gas treatment method, and a method for retrofitting an exhaust gas treatment system.

Background Art

[0002] In manufacturing processes such as semiconductors, liquid crystals, LEDs (Light Emitting Diodes), and solar cells, various gases are used, including perfluorinated compound (PFC) gases. For example, in a semiconductor manufacturing factory, CF 4 , SF 6 , CHF 3 etc. are used in the dry etching process, and NF 3 , C 2 F 6 , C 3 F 8 etc. are used in thin film formation processes such as CVD (Chemical Vapor Deposition), and exhaust gas containing these PFC gases is generated. PFC gases are harmful and are also greenhouse gases.

[0003] As equipment for treating exhaust gas containing PFC gas etc., exhaust gas treatment equipment (decontamination device) that treats exhaust gas by combustion decontamination etc. is known (for example, Patent Document 1 etc.). Furthermore, wastewater treatment equipment that treats wastewater from the exhaust gas treatment equipment and returns it to the exhaust gas treatment equipment is also known (for example, Patent Document 2 etc.).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, due to the miniaturization or multi-layerization of semiconductor devices, the amount of gas used in the semiconductor manufacturing process has been on the increase. Along with this, the amount of harmful substances to be removed (or decomposed) has also increased. As a result, the scale of the exhaust gas treatment equipment and the wastewater treatment equipment has become larger, and the plant cost and the operation cost have increased.

[0006] An object of the present invention is to provide an exhaust gas treatment system, an exhaust gas treatment method, and a method for an exhaust gas treatment system that can suppress the enlargement of the exhaust gas treatment equipment and the wastewater treatment equipment and can suppress an increase in the plant cost and the operation cost. Reform is to provide.

Means for Solving the Problems

[0007] To achieve the above object, according to one aspect of the present invention, there is provided an exhaust gas treatment system including: an exhaust gas separation unit that receives a first gas containing a specific substance, separates a part of the specific substance contained in the first gas, and discharges a second gas having a lower content of the specific substance than the first gas; a solubilization unit that treats the second gas to solubilize the specific substance; a dissolution unit that dissolves the solubilized specific substance in supply water and discharges first wastewater; and wastewater treatment equipment that receives the first wastewater, removes the specific substance from the first wastewater, and recovers the wastewater from which the specific substance has been removed as makeup water for the supply water.

[0008] According to another aspect of the present invention, there is provided an exhaust gas treatment method including: a step of receiving a first gas containing a specific substance, separating a part of the specific substance contained in the first gas, and discharging a second gas having a lower content of the specific substance than the first gas; a step of treating the second gas to solubilize the specific substance; a step of dissolving the solubilized specific substance in supply water and discharging first wastewater; and a step of receiving the first wastewater, removing the specific substance from the first wastewater, and recovering the wastewater from which the specific substance has been removed as makeup water for the supply water.

[0009] According to still another aspect of the present invention, there is provided a method for retrofitting an exhaust gas treatment system, comprising: a decontamination device that treats exhaust gas containing a specific substance to solubilize the specific substance, dissolves the solubilized specific substance in supply water, and discharges first drainage water; and wastewater treatment equipment that receives the first drainage water, removes the specific substance from the first drainage water, and recovers the drainage water from which the specific substance has been removed as makeup water for the supply water. The method includes providing an exhaust gas separation device that receives a first gas containing the specific substance, separates a part of the specific substance contained in the first gas, and discharges, as the exhaust gas, a second gas having a lower content of the specific substance than the first gas to the decontamination device.

Advantages of the Invention

[0010] According to the present invention, it is possible to suppress the enlargement of exhaust gas treatment equipment and wastewater treatment equipment, and to suppress an increase in plant costs and operating costs.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the components described in the embodiments are merely examples and are not intended to limit the scope of the present invention thereto.

[0013] (First Embodiment) FIG. 1 is a schematic diagram showing the configuration of an exhaust gas treatment system according to the first embodiment of the present invention. In FIG. 1, the solid arrows schematically show the pipes. Referring to FIG. 1, the exhaust gas treatment system 10 includes an exhaust gas separation device (exhaust gas separation section) 11, a pest control device (exhaust gas treatment facility) 12, and a wastewater treatment facility 13.

[0014] In the present embodiment, the exhaust gas separation device 11 and the pest control device 12 are installed in the manufacturing building 20. The manufacturing building 20 is provided with a plurality of gas treatment devices 21 that discharge a first gas 22a containing a specific substance. The pest control device 12 communicates with at least one gas treatment device 21 via the exhaust gas separation device 11. In the present embodiment, the pest control device 12 communicates with the gas treatment device 21 performing a thin film forming process and the gas treatment device 21 performing a dry etching process via the exhaust gas separation device 11. The thin film forming process may include, for example, a CVD process, but is not limited thereto.

[0015] In the dry etching process, for example, CF 4 , SF 6 , CHF3 PFC gases such as are used, and in the thin film forming process, for example, NF 3 , C 2 F 6 , C 3 F 8 and other PFC gases, and semiconductor material gases such as SiH 4 and NH 3 , SiH 2 CL 2 are used. Also, for cleaning inside the gas processing apparatus, gases such as NF 3 and CL 2 are used. The gas processing apparatus 21 discharges a first gas 22a containing these gases. The gases not used in the reaction are discharged together with the gases decomposed in the reaction (HF, CO 2 , decomposition gases, etc.). In each gas processing apparatus 21, for discharging the first gas 22a, for example, a vacuum pump may be used. In this case, for protecting the equipment after the vacuum pump and for safety purposes, a large amount of nitrogen (N 2 ) gas may be introduced. Here, the first gas 22a contains a specific substance. The specific substance may contain one or both of fluorine (F) and fluorine compounds. Also, the specific substance may contain one or both of nitrogen (N) and nitrogen compounds. Note that the specific substance is not limited to fluorine and fluorine compounds or nitrogen and fluorine compounds. For example, the specific substance may contain other components such as a carbon source (C), chlorine (Cl), silicon (Si), and their compounds. In other words, the specific substance may contain one or both of at least one component of fluorine, nitrogen, carbon, and silicon and the compound of the component.

[0016] The exhaust gas separation device 11 is for the gas processing device (film forming device) 21 and the gas processing device (dry etching Device)21 receives the first gas 22a discharged respectively. The first gas 22a may contain decomposition products and by-products of the gas discharged from the gas treatment device 21. The exhaust gas separation device 11 separates a part of a specific substance contained in the first gas 22a and discharges a second gas 22b in which the content of the specific substance is less than that of the first gas 22a. In the present embodiment, fluorine and / or its compounds are assumed as the specific substance, and the exhaust gas separation device 11 separates and recovers a part of the fluorine contained in the first gas 22a. In this case, for example, the exhaust gas separation device 11 may recover fluorine as a valuable substance.

[0017] The exhaust gas separation device 11 may have any configuration as long as it can recover a specific substance (here, fluorine) from the first gas 22a. As general gas recovery techniques, a cryogenic distillation method that separates by boiling point difference, a pressure swing adsorption (PSA) method or a temperature swing adsorption (TSA) method that repeats adsorption and desorption, and a membrane separation method using a gas separation membrane are known. Any one or a combination of these gas recovery techniques may be applied to the exhaust gas separation device 11.

[0018] When separating and recovering a specific substance in the exhaust gas separation device 11, the recovery rate R1 of the specific substance can be set to a value that is theoretically or practically possible according to the substance to be recovered and the recovery method. For example, in the present embodiment, the specific substance is fluorine, and the exhaust gas separation device 11 is configured such that the recovery rate R1 of fluorine is 50%. Here, the recovery rate R1 of fluorine indicates, for example, the recovery rate with respect to the total fluorine load when the first gas 22a is a mixed gas such as NF 3 , CF 4 , SF 6 and so on.

[0019] The decontamination device 12 receives the supply water including the makeup water 24 from the wastewater treatment facility 13 and the second gas 22b discharged from the exhaust gas separation device 11. The decontamination device 12 burns the second gas 22b to decontaminate harmful substances containing specific substances, and discharges the wastewater in which the components derived from the decomposed harmful substances are dissolved in the supply water. Here, since fluorine is assumed as the specific substance, the decontamination device 12 discharges the first wastewater 23a in which fluorine is dissolved in the supply water.

[0020] The configuration of the decontamination device 12 will be specifically described. FIG. 2 is a schematic diagram showing one configuration example of the decontamination device 12. In FIG. 2, the solid-line arrow schematically shows the pipe through which the liquid flows, and the broken-line arrow schematically shows the pipe through which the gas flows. Referring to FIG. 2, the decontamination device 12 has a solubilization unit 121 and a dissolution unit 122. The solubilization unit 121 treats the second gas 22b to solubilize specific substances. The dissolution unit 122 dissolves the specific substances solubilized by the solubilization unit 121 in the supply water 25 and discharges the first wastewater 23a. The supply water 25 may include the makeup water 24.

[0021] The solubilization unit 121 may include, for example, a combustion chamber in which a combustion process using a burner is performed. The second gas 22b is supplied to the combustion chamber, and the second gas 22b is decomposed by a thermal decomposition reaction (solubilization of specific substances). In this case, the combustion chamber may be cooled with the supply water 25 including the makeup water 24. The water used for cooling is discharged as the first wastewater 23a. The dissolution unit 122 may include, for example, a scrubber that sprays water on the gas. The gas in the combustion chamber of the solubilization unit 121 is supplied to the scrubber. In the scrubber, the specific substances remaining in the gas are dissolved in water by spraying water (dissolution). The water in which the specific substances are dissolved is discharged from the bottom of the scrubber as the first wastewater 23a.

[0022] Note that the solubilization unit 121 and the dissolution unit 122 may be the same device. Also, the combination of the combustion chamber constituting the solubilization unit 121 and the scrubber constituting the dissolution unit 122 is not limited to the one described above. For example, scrubbers may be provided on the inlet side and the outlet side of the combustion chamber, respectively. Also, a flue gas washing chamber for spraying water on the gas may be provided between the combustion chamber and the scrubber. Further, as the decontamination device 12, for example, an existing decontamination device that removes specific substances using electric heating or plasma may be used. Although a detailed description of such a decontamination device is omitted, a device with a general configuration can be used.

[0023] The wastewater treatment facility 13 receives the first wastewater 23a discharged from the decontamination device 12. The wastewater treatment facility 13 removes a specific substance (here, fluorine) from the first wastewater 23a and supplies the wastewater from which the specific substance has been removed to the decontamination device 12 as makeup water 24 for the supply water 25. The wastewater treatment facility 13 further discharges the second wastewater 23b containing the removed specific substance.

[0024] Fig. 3 shows an example of the wastewater treatment facility 13. As shown in Fig. 3, the wastewater treatment facility 13 includes a raw water tank 130, a heat exchanger 131, a neutralization tank 132, a biological reaction tank (biological treatment) 133, an intermediate tank 134, an ultrafiltration device (UF) 135, an intermediate tank 136, a reverse osmosis membrane filtration device (RO) 137, and a makeup water tank 138. The first drainage water 23a discharged by the decontamination device 12 is stored in the raw water tank 130 as the water to be treated. The raw water tank 130 and the heat exchanger 131 are communicated with each other via a pipe, and a pump 139a is provided in this pipe. The heat exchanger 131 and the neutralization tank 132 are communicated with each other via a pipe. The neutralization tank 132 and the biological reaction tank 133 are communicated with each other via a pipe. The biological reaction tank 133 and the intermediate tank 134 are communicated with each other via a pipe. The intermediate tank 134 and the UF 135 are communicated with each other via a pipe. The UF 135 and the intermediate tank 136 are communicated with each other via a pipe. The intermediate tank 136 and the RO 137 are communicated with each other via a pipe, and a pump 139b is provided in this pipe. The RO 137 and the makeup water tank 138 are communicated with each other via a pipe. A drainage pipe is connected to the makeup water tank 138, and a pump 139c is provided in this pipe. By controlling the pumps 139a to 139c, the water to be treated stored in the raw water tank 130 can be supplied to the heat exchanger 131, the neutralization tank 132, the biological reaction tank 133, the intermediate tank 134, the UF (ultrafiltration membrane device) 135, the intermediate tank 136, the RO (reverse osmosis membrane device) 137, and the makeup water tank 138 in sequence at an appropriate timing.

[0025] The heat exchanger 131 performs heat exchange treatment using cooling water. The neutralization tank 132 performs neutralization treatment using a neutralizing agent. The neutralized water to be treated is supplied to the biological reaction tank 133 after adding a nutrient agent. The biological reaction tank 133 performs biological treatment. The biological reaction tank 133 is provided with a mechanism for aerating the water to be treated (an air bubbling mechanism for supplying oxygen necessary for microorganisms). The biologically treated water is supplied to the UF 135 via the intermediate tank 134. The UF 135 filters the biologically treated water using a plurality of UF membranes having fine pore diameters. The filtered water of the UF 135 is stored in the intermediate tank 136, and then a dispersant and a slime control agent are added and supplied to the RO 137. The RO 137 further filters the filtered water of the UF 135 using a plurality of RO membranes. The filtered water (permeate water) of the RO 137 is stored in the makeup water tank 138. The stored water in this makeup water tank 138 has NaCLO added thereto, is discharged as makeup water 24, and is supplied to the decontamination device 12. The concentrated water separated by the UF 135 and the RO 137 is discharged as the second drainage water 23b.

[0026] According to the exhaust gas treatment system 10 of the present embodiment described above, by separating a part of the specific substances (components such as fluorine) contained in the first gas 22a by the exhaust gas separation device 11, it is possible to reduce the cooling energy required for the decontamination device 12. As a result, it is possible to suppress the enlargement of the decontamination device 12 and the wastewater treatment facility 13, and to suppress an increase in the plant cost and the operation cost. Hereinafter, this operational effect will be specifically described with reference to a comparative example.

[0027] (Comparative Example 1) FIG. 4 is a schematic diagram showing the exhaust gas treatment system of Comparative Example 1. The exhaust gas treatment system 100 of Comparative Example 1 is different from the exhaust gas treatment system 10 of the present embodiment in that it does not include the exhaust gas separation device 11. In the exhaust gas treatment system 100, the configuration other than the exhaust gas separation device 11 is basically the same as that of the exhaust gas treatment system 10. In the exhaust gas treatment system 100, the first gas 22a discharged from each gas treatment device 21 is directly supplied to the decontamination device 12. For this reason, compared with the configuration including the exhaust gas separation device 11, the amount of harmful substances to be decontaminated (or decomposed) increases, and accordingly, the calorific value of the decontamination device 12 increases, and the amount of the supply water 25 required for cooling increases. As a result, the amount of the first wastewater 23a discharged from the decontamination device 12 increases, the scale of the wastewater treatment facility and the recovery facility becomes large, and the plant cost and the operation cost increase.

[0028] Assuming that fluorine (F) is a specific substance contained in the exhaust gas, the above problem will be specifically described. In the exhaust gas treatment system 100, assume that the amount of fluorine per day in the first gas 22a supplied to the decontamination device 12 is, for example, 2,000 kg / d. In the decontamination device 12, the thermal energy required to process 2,000 kg / d of fluorine is consumed, and the supply water 25 in an amount corresponding to the calorific value is used. The daily discharge amount of the first wastewater 23a discharged from the decontamination device 12 is 20,000 m 3Assume it is / d. The amount of fluorine per day contained in the first drainage 23a is 2,000 kg / d. Note that the first drainage 23a also contains components other than fluorine. The F concentration of the second drainage 23b is, for example, 2,000 mg / L.

[0029] In contrast, in the exhaust gas treatment system 10 of the present embodiment 、Drain The gas separation device 11 recovers a part of the fluorine contained in the first gas 22a. Here, since the recovery rate R1 of fluorine is 50%, assuming that the amount of fluorine per day in the first gas 22a is 2,000 kg / d, the amount of fluorine per day in the second gas 22b supplied to the decontamination device 12 is 1,000 kg / d. In the decontamination device 12, the thermal energy required to process 1,000 kg / d of fluorine is consumed, and the amount of supply water 25 corresponding to the calorific value is used. The amount of this supply water 25 can be reduced compared to Comparative Example 1. Specifically, the daily discharge amount of the first drainage 23a discharged from the decontamination device 12 is 20,000 m 3 / d compared to 3 It can be reduced to 15,000 m

[0030] As described above, according to the exhaust gas treatment system 10 of the present embodiment, compared with Comparative Example 1, the discharge amount of the first drainage 23a discharged from the decontamination device 12 and the amount of fluorine contained in the first drainage 23a can be reduced. Thereby, the scales of the decontamination device 12 and the wastewater treatment facility 13 can be reduced, and the plant cost and the operation cost can be reduced. Here, the reduction of the plant cost includes the reduction of the construction cost of the plant facilities and the reduction of the installation space due to the scale reduction. Also, the operation cost includes the energy cost related to operation, the cost of chemicals such as neutralizing agents required to recover decomposed specific substances (components such as fluorine), and the waste treatment cost such as sludge. The reduction of the operation cost includes the reduction of the chemical input amount and the reduction of the energy cost (power consumption).

[0031] In addition, when the amount of harmful substances to be removed (or decomposed) increases with the increase in the amount of exhaust gas, the energy consumption and heat generation of the removal device increase, and the amount of makeup water for cooling and the amount of makeup water required to dissolve components derived from harmful substances increase. As a result, the drainage volume and load of the removal device increase, the scale of the wastewater treatment facility becomes larger, and the plant cost and operation cost increase. According to the exhaust gas treatment system 10 of the present embodiment, since the discharge amount of the first drainage 23a discharged from the removal device 12 and the amount of fluorine contained in the first drainage 23a can be reduced, even when the amount of harmful substances to be removed (or decomposed) increases with the increase in the amount of exhaust gas, an increase in the energy consumption and heat generation of the removal device 12, and an increase in the amount of makeup water for cooling and the amount of makeup water required to dissolve components derived from harmful substances can be suppressed. As a result, an increase in the drainage volume and load of the removal device 12 and an increase in the scale of the wastewater treatment facility 13 can be suppressed, and an increase in the plant cost and operation cost can be suppressed.

[0032] Specifically, in the removal device 12 shown in FIG. 2, due to a decrease in the supply amount and load of the second gas 22b, it is possible to reduce energy such as the fuel and electricity of the burner in the solubilization unit 121. Due to a decrease in the supply amount (required amount) of the supply water 25, it is possible to reduce / downsize the scale / capacity of the supply facilities such as pipes / water supply pumps for supplying the supply water 25 to the dissolution unit 122. Due to a decrease in the flow rate of the second gas 22b, it is possible to downsize the scale of the solubilization unit 121 and auxiliary equipment, downsize the scale of the dissolution unit 122 and auxiliary equipment, and downsize the scale of the supply facilities such as pipes / water supply pumps for draining the first drainage 23a.

[0033] In addition, in the wastewater treatment facility 13 shown in FIG. 3, due to a decrease in the amount of the first drainage 23a, it is possible to downsize each of the raw water tank 130, heat exchanger 131, neutralization tank 132, biological reaction tank 133, intermediate tank 134, UF 135, intermediate tank 136, RO 137, and makeup water tank 138, and it is also possible to downsize the pipes connecting them. For example, in Comparative Example 1, the volume of the neutralization tank 132 was 209 m 3 , and the volume of the biological reaction tank 133 was 834 m 3Then, in the exhaust gas treatment system 10 of the present embodiment, the volume of the neutralization tank 132 can be reduced to 157 m 3 , and the volume of the biological reaction tank 133 can be reduced to 625 m 3 . Also, due to the reduction in the amount of the first wastewater 23a, it is possible to reduce the input amounts (required amounts) of cooling water, neutralizing agent, nutrient agent, dispersant, slime control agent, and NaCLO. Furthermore, due to the reduction in the TOC (total organic carbon) load, which is a component contained in the first wastewater 23a, it is possible to reduce the scale of the biological reaction tank 133.

[0034] Furthermore, due to the reduction in the load of silica (silicic acid) and solids, which are components contained in the first wastewater 23a, the number of UF membranes can be reduced, and the scale of UF135 can be reduced. For example, in Comparative Example 1, if UF135 is provided with 223 UF membranes, then in the exhaust gas treatment system 10 of the present embodiment, the number of UF membranes of UF135 can be reduced to 150. Furthermore, due to the reduction in the load of the components (ions) of the second wastewater 23b, the number of RO membranes can be reduced, and the scale of RO137 can be reduced. For example, in Comparative Example 1, if RO137 is provided with 1012 RO membranes, then in the exhaust gas treatment system 10 of the present embodiment, the number of RO membranes of RO137 can be reduced to 655.

[0035] Also, according to the exhaust gas treatment system 10 of the present embodiment, the water recovery rate R2 of the wastewater treatment facility 13 can be improved as compared with Comparative Example 1. For example, the water recovery rate R2 of the wastewater treatment facility 13 may be rate-limited by the CaF 2 scale on the RO membrane concentrate side. When the fluorine concentration on the RO membrane concentrate side is the same 2000 mg / L, in Comparative Example 1, it is 95%, while in the present embodiment, it is 97%. Note that the water recovery rate R2 of the wastewater treatment facility 13 changes according to the fluorine recovery rate R1 of the exhaust gas separation device 11. Specifically, when the amount of wastewater discharged from the decontamination device 12 is constant (when the amount of water supplied to the wastewater treatment facility 13 is constant), the higher the fluorine recovery rate R1, the higher the water recovery rate R2 can be. For example, when the fluorine recovery rate R1 is 70%, the water recovery rate R2 can be set to 98%. Table 1 shows the comparison results between this embodiment (fluorine recovery rate R1: 50% / 70%) and Comparative Example 1.

Table 1

[0036] (Second Embodiment) FIG. 5 is a schematic diagram showing the configuration of the exhaust gas treatment system according to the second embodiment of the present invention. The exhaust gas treatment system 10A of this embodiment is different from the first embodiment in that it has a water treatment device 16. Since the exhaust gas separation device 11, the decontamination device 12, and the wastewater treatment facility 13 are the same as those in the first embodiment, detailed descriptions of these configurations are omitted here.

[0037] The water treatment device 16 receives the second wastewater 23b discharged from the wastewater treatment facility 13 and performs water treatment to remove specific substances from the second wastewater 23b. Here, fluorine is assumed as the specific substance, and the water treatment device 16 includes a fluorine-based wastewater device 14 and a total wastewater device 15.

[0038] The fluorine-based wastewater device 14 receives the second wastewater 23b and aggregates and precipitates the fluorine contained in the second wastewater 23b. FIG. 6 shows the specific configuration of the fluorine-based wastewater device 14. As shown in FIG. 6, the fluorine-based wastewater device 14 includes reaction tanks 140 and 141, a coagulation tank 142, a sedimentation tank 143, and a dehydrator 144. The reaction tank 140 and the reaction tank 141 are connected in communication via a pipe. The reaction tank 141 and the coagulation tank 142 are connected in communication via a pipe. The coagulation tank 142 and the sedimentation tank 143 are connected in communication via a pipe. The sedimentation tank 143 and the dehydrator 144 are connected in communication via a pipe. The second wastewater 23b discharged by the wastewater treatment facility 13 is stored in the reaction tank 140. In the reaction tank 140, Ca(OH) 2 (calcium hydroxide) is introduced. The wastewater into which calcium hydroxide has been introduced is stored in the reaction tank 141. In the reaction tank 141, PAC (polyaluminum chloride) and NaOH (sodium hydroxide) are introduced. PAC is a flocculant that makes the turbidity substances contained in the wastewater easy to aggregate and precipitate. NaOH is an alkaline agent for adjusting the pH of the wastewater.

[0039] The stored water in the reaction tank 141 is supplied to the sedimentation tank 143 via the flocculation tank 142. In the flocculation tank 142, the turbidity substances contained in the wastewater aggregate, and flocs (aggregates) that are minute lumps precipitate. In the sedimentation tank 143, the flocs (aggregates) precipitate. The sediment is supplied to the dehydrator 144, and the wastewater from which the sediment has been removed is supplied to the total wastewater discharge device 15 as wastewater. In the dehydrator 144, the sediment is dehydrated and discharged as sludge. The above has described the coagulation sedimentation method using calcium hydroxide. However, for example, a crystallization reaction device for obtaining calcium fluoride crystals such as Patent No. 5650164 may be used, and the fluorine-based wastewater treatment device 14 is not limited to these methods.

[0040] The total wastewater discharge device 15 receives the wastewater discharged by the fluorine-based wastewater treatment device 14 and performs neutralization treatment. Fig. 7 shows the specific configuration of the total wastewater discharge device 15. As shown in Fig. 7, the total wastewater discharge device 15 has a reaction tank 150, a flocculation tank 151, and a float separation tank 152. The reaction tank 150 and the flocculation tank 151 are in communication via a pipe. The flocculation tank 151 and the float separation tank 152 are in communication via a pipe. The wastewater discharged from the sedimentation tank 143 of the fluorine-based wastewater treatment device 14 is stored in the reaction tank 150. In the reaction tank 150, PAC and NaOH are introduced. The stored water in the reaction tank 150 is supplied to the floatation separation tank 152 via the coagulation tank 151. In the coagulation tank 151, the turbidity substances contained in the water to be treated are coagulated and flocs are precipitated. The floatation separation tank 152 is a solid-liquid separation tank. In the floatation separation tank 152, pressurized water in which gas is dissolved under pressure is injected from the lower part of the tank, and bubbles are attached to the flocs to give buoyancy for floatation separation. The clean water at the lower part of the stored water in the floatation separation tank 152 is discharged as floatation separation treated water. The floatation separation treated water can be discharged into, for example, rivers or the ocean, and can also be reused as recovered water.

[0041] According to the exhaust gas treatment system 10A of the present embodiment described above, by the exhaust gas separation device 11 recovering a part of the specific substance contained in the first gas 22a, it is possible to simultaneously achieve a reduction in the cooling energy required for the decontamination device 12 and a reduction in the treatment load of the specific substance (here, fluorine) in the water treatment device 16. As a result, in addition to the effects described in the first embodiment, with respect to the water treatment device 16, the scale of the facility can be reduced, and the plant cost and the operation cost can be reduced. In addition, the amount of sludge generated by fluorine coagulation sedimentation can be reduced. Hereinafter, this operational effect will be specifically described with reference to a comparative example.

[0042] (Comparative Example 2) FIG. 8 is a schematic diagram showing the exhaust gas treatment system of Comparative Example 2. The exhaust gas treatment system 100A of Comparative Example 2 is different from the exhaust gas treatment system 10A of the present embodiment in that it does not include the exhaust gas separation device 11. In the exhaust gas treatment system 100A, the configuration other than the exhaust gas separation device 11 is basically the same as that of the exhaust gas treatment system 10A.

[0043] In the exhaust gas treatment system 100A, the daily discharge amount of the second wastewater 23b discharged from the wastewater treatment facility 13 is, for example, 1,000 m 3Assume it is / d. The amount of fluorine per day contained in the second wastewater 23b is 2,000 kg / d. The fluorine-based wastewater treatment device 14 coagulates and precipitates 2,000 kg / d of fluorine and removes it as 8.4 t of sludge substances. The daily discharge amount of the wastewater discharged by the fluorine-based wastewater treatment device 14 is 880 m 3 / d. Assume the amount of wastewater treated by the total wastewater treatment device 15 is 880 m 3 / d. Assume.

[0044] According to the exhaust gas treatment system 10A of the present embodiment, the daily discharge amount of the second wastewater 23b discharged by the wastewater treatment facility 13 can be reduced from 1,000 m 3 / d in Comparative Example 2 to 500 m 3 / d. Also, the amount of fluorine per day contained in the second wastewater 23b can be reduced from 2,000 kg / d in Comparative Example 2 to 1,000 kg / d. As a result, the fluorine-based wastewater treatment device 14 coagulates and precipitates 1,000 kg / d of fluorine, and thus the amount of sludge can be reduced from 8.4 t in Comparative Example 2 to 4.2 t. Also, the daily discharge amount of the wastewater discharged by the fluorine-based wastewater treatment device 14 can be reduced from 880 m 3 / d in Comparative Example 2 to 440 m 3 / d, and thereby the amount of wastewater treated by the total wastewater treatment device 15 can also be reduced from 880 m 3 / d in Comparative Example 2 to 440 m 3 / d.

[0045] As described above, according to the exhaust gas treatment system 10A of the present embodiment, compared with Comparative Example 2, the amount of fluorine treated by the fluorine-based wastewater treatment device 14 can be halved. Therefore, the scale of the equipment of the fluorine-based wastewater treatment device 14 can be reduced, and the amount of chemicals input required for the coagulation and precipitation treatment can be reduced.

[0046] Specifically, in the fluorine-based wastewater treatment device 14 shown in FIG. 6, due to the reduction in the amount of the second wastewater 23b and the reduction in the fluorine amount, it is possible to reduce the scale of each of the reaction tanks 140, 141, the coagulation tank 142, the sedimentation tank 143, and the dehydrator 144, and it is also possible to reduce the scale of the pipes connecting them. For example, in Comparative Example 2, if the volume of the reaction tank 140 is 11 m 3 , the volume of the reaction tank 141 is 11 m 3 , the volume of the coagulation tank 142 is 4 m 3 , the area of the sedimentation tank 143 is 4 m 2 , and the membrane area of the dehydrator 144 is 56 m 2 , then in the exhaust gas treatment system 10A of the present embodiment, the volume of the reaction tank 140 can be reduced to 6 m 3 , the volume of the reaction tank 141 can be reduced to 6 m 3 , the volume of the coagulation tank 142 can be reduced to 2 m 3 , the area of the sedimentation tank 143 can be reduced to 2 m 2 , and the membrane area of the dehydrator 144 can be reduced to 28 m 2 . By reducing the scale of these facilities, the plant cost can be reduced by about 50%.

[0047] Also, in Comparative Example 2, if the input amount of Ca(OH) 2 is 4,200 kg / d, the input amount of PAC is 300 kg / d, and the input amount of NaOH (caustic soda) is 163 kg / d, then in the exhaust gas treatment system 10A of the present embodiment, the input amount of Ca(OH) 2 can be reduced to 2,100 kg / d, the input amount of PAC can be reduced to 151 kg / d, and the input amount of NaOH can be reduced to 82 kg / d. Also, in the total wastewater treatment device 15 shown in FIG. 7, due to the reduction in the amount of the second wastewater 23b and the reduction in the fluorine amount, it is possible to reduce the scale of each of the reaction tank 150, the coagulation tank 151, and the flotation separation tank 152, and it is also possible to reduce the scale of the pipes connecting them. For example, in Comparative Example 2, if the volume of the reaction tank 150 is 10 m 3 , the volume of the coagulation tank 151 is 4 m 3 , and the area of the flotation separation tank 152 is 2 m 2 , then in the exhaust gas treatment system 10A of the present embodiment, the volume of the reaction tank 150 can be reduced to 5 m 3 , the volume of the coagulation tank 151 can be reduced to 2 m 3, the area of the floating separation tank 152 can be reduced to 1 m 2 . By reducing these facilities, the plant cost can be reduced by about 50%. Also, in Comparative Example 2, when the input amount of PAC is 264 kg / d and the input amount of NaOH is 143 kg / d, in the exhaust gas treatment system 10A of this embodiment, the input amount of PAC can be reduced to 133 kg / d and the input amount of NaOH can be reduced to 72 kg / d.

[0048] Table 2 shows the comparison results between this embodiment and Comparative Example 2.

Table 2

[0049] The first and second embodiments described above are examples of the present invention, and each component of the exhaust gas treatment system 10 (10A) can be appropriately changed as long as it does not prevent the operational effects described in each embodiment. In the first and second embodiments described above, the decontamination device 12 and the gas treatment device 21 are arranged in any one of the connection forms of one-to-one, one-to-many, many-to-one, and many-to-many, or in a combination of two or more connection forms, and the exhaust gas separation device 11 may be incorporated into at least one gas treatment device 21.

[0050] FIG. 9 is a schematic diagram for explaining the connection form between the decontamination device 12 and the gas treatment device 21. In FIG. 9, the solid-line arrows schematically show the pipes through which the gas passes. One solid line may indicate a single pipe or a plurality of pipes. As shown in FIG. 9(a), the decontamination device 12 and the gas treatment device (film-forming device) 21 are arranged in a many-to-many connection form, and the decontamination device 12 and the gas treatment device (dry etching Device)21 are arranged in a many-to-many connection form. In the many-to-many connection form between the decontamination device 12 and the gas treatment device (film forming device) 21, the exhaust gas separation device 11 may be provided anywhere in the communication pipe connecting the decontamination device 12 and the gas treatment device (film forming device) 21. For example, the exhaust gas separation device 11 may be provided for each gas treatment device (film forming device) 21 or for each decontamination device 12, or may be provided in a collective part where two or more gas treatment devices (film forming devices) 21 are connected or in a collective part where two or more decontamination devices 12 are connected. Similarly, in the many-to-many connection form between the decontamination device 12 and the gas treatment device (dry etching Device )21, the exhaust gas separation device 11 may be provided anywhere in the communication pipe connecting the decontamination device 12 and the gas treatment device (dry etching Device )21. For example, the exhaust gas separation device 11 may be provided for each gas treatment device (dry etching Device )21, or may be provided in a collective part where two or more gas treatment devices (dry etching Device )21 are connected.

[0051] As shown in FIG. 9(b), the decontamination device 12 and the gas treatment device (film forming device) 21 are arranged in a one-to-one connection form, and the decontamination device 12 and the gas treatment device (dry etching Device )21 are arranged in a one-to-one connection form. In this case, the exhaust gas separation device 11 may be provided for at least one gas treatment device (film forming device) 21. Similarly, the exhaust gas separation device 11 may be provided for at least one gas treatment device (dry etching Device )21.

[0052] As shown in FIG. 9(c), the decontamination device 12 and the gas treatment device (film forming device) 21 are arranged in a many-to-one connection form, and the decontamination device 12 and the gas treatment device (dry etching Device)21 are arranged in a many-to-one connection form. In the many-to-one connection form between the exhaust gas purification device 12 and the gas processing device (film forming device) 21, the exhaust gas separation device 11 may be provided anywhere in the communication pipe connecting the exhaust gas purification device 12 and the gas processing device (film forming device) 21. For example, the exhaust gas separation device 11 may be provided for each exhaust gas purification device 12, or may be provided in an assembly portion to which two or more exhaust gas purification devices 12 are connected. Similarly, in the many-to-one connection form between the exhaust gas purification device 12 and the gas processing device (dry etching Device )21, in the many-to-one connection form, the exhaust gas separation device 11 may be provided anywhere in the communication pipe connecting the exhaust gas purification device 12 and the gas processing device (dry etching Device )21. For example, the exhaust gas separation device 11 may be provided for each exhaust gas purification device 12, or may be provided in an assembly portion to which two or more exhaust gas purification devices 12 are connected.

[0053] Also, although not shown in FIG. 9, the exhaust gas purification device 12 and the gas processing device (film forming device) 21 may be arranged in a one-to-many connection form. Similarly, the exhaust gas purification device 12 and the gas processing device (dry etching Device )21 may be arranged in a one-to-many connection form. In any connection form, the exhaust gas separation device 11 may be provided for at least one gas processing device 21. Further, as the connection form between the exhaust gas purification device 12 and the gas processing device (film forming device) 21 and the gas processing device (dry etching Device )21, two or more of the four connection forms of one-to-one, one-to-many, many-to-one, and many-to-many may be combined. Also in this case, the exhaust gas separation device 11 may be provided for at least one gas processing device 21. Also, in each of the above-described connection forms, the exhaust gas separation device 11 may be incorporated into at least one gas processing device 21.

[0054] Hereinafter, an arrangement example of the exhaust gas separation device 11 will be specifically described. FIG. 10 is a schematic diagram showing an example of the arrangement of the exhaust gas separation device 11. In FIG. 10, the solid-line arrows schematically show the pipes through which the gas passes. One solid line may indicate a single pipe or a plurality of pipes. In the example shown in FIG. 10, a many-to-many connection form between two decontamination devices 12 and three gas treatment devices 21 is adopted. As the gas treatment device 21, a film forming device or a dry etching device can be used. The arrangement positions A1 to A6 indicate positions where the exhaust gas separation device 11 can be arranged. The arrangement positions A1 and A2 respectively indicate the arrangements on the gas supply pipes of the two decontamination devices 12. The arrangement position A3 indicates the arrangement on the collective part of the pipes from each gas treatment device 21. The arrangement positions A4 to A6 respectively indicate the arrangements on the pipes from each gas treatment device 21.

[0055] The exhaust gas separation device 11 may be provided at any of the arrangement positions A1 to A6. Further, the exhaust gas separation device 11 may be provided at two or more of the arrangement positions A4 to A6. Additionally, the exhaust gas separation device 11 may be provided at both of the arrangement positions A1 and A2. Note that the number of gas treatment devices 21 may be two or more. In this case, the exhaust gas separation device 11 may be provided for one or more gas treatment devices 21. Also, the number of decontamination devices 12 may be three or more. In this case, the exhaust gas separation device 11 may be provided for one or more decontamination devices 12.

[0056] FIG. 11 is a schematic diagram showing another example of the arrangement of the exhaust gas separation device 11. In FIG. 11, the solid arrows schematically show the pipes through which the gas passes. In the example shown in FIG. 11, the arrangement positions A1 to A9 of the exhaust gas separation device 11 with respect to one gas treatment device (film forming device) 21 are shown. The gas treatment device (film forming device) 21 includes four chambers 21a. Pumps 30 are provided in the pipes on the discharge sides of the respective chambers 21a. The pipes on the discharge sides of the respective pumps 30 merge into one. The arrangement position A1 indicates the arrangement on the collective part of the pipes from each pump. The arrangement positions A2 to A5 respectively indicate the arrangements on the pipes on the discharge sides of the respective pumps 30. The arrangement positions A6 to A9 respectively indicate the arrangements on the pipes on the discharge sides of the respective chambers 21a. The exhaust gas separation device 11 may be provided at any of the arrangement positions A1 to A9. Further, the exhaust gas separation device 11 may be provided at two or more of the arrangement positions A2 to A5. Furthermore, the exhaust gas separation device 11 may be provided at two or more of the arrangement positions A6 to A9. Note that the number of chambers 21a may be two or more. In this case, the exhaust gas separation device 11 may be provided for one or more chambers 21a.

[0057] FIG. 12 is a schematic diagram showing still another example of the arrangement of the exhaust gas separation device 11. In FIG. 12, the solid arrows schematically show the pipes through which the gas passes. The chamber 21a, the pump 30, and the pipes are the same as those shown in FIG. 11. Valves 31 are provided in the pipes from each pump 30, and two pipes are provided from before and after this valve 31 toward the exhaust gas separation device 11. One of the two pipes is a supply line, and the other is a discharge line. A valve 32 is provided in the supply line, and a valve 33 is provided in the discharge line. Each supply line is connected to the exhaust gas separation device 11 by being connected to one line. Each discharge line is also connected to the exhaust gas separation device 11 by being connected to one line. By operating the three valves 31 to 33 provided for each chamber 21a, each chamber 21a can be individually connected to the exhaust gas separation device 11. For example, when performing a cleaning process on each chamber 21a in order, the chamber 21a on which the cleaning process is performed is connected to the exhaust gas separation device 11. Thereby, the recovery (separation) of the exhaust gas can be efficiently performed. Further, according to this arrangement form, compared with the arrangement forms shown in FIGS. 10 and 11, the amount of exhaust gas is the smallest, and the concentration (load amount) of the gas to be treated can be increased. Therefore, the recovery facility can be made smaller and the recovery efficiency is also improved. Note that in the arrangement form shown in FIG. 12, the path switching unit using the valves 31 to 33 may be provided in at least one chamber 21a. Further, the number of chambers 21a is not limited to four. The number of chambers 21a may be two or more.

[0058] FIG. 13 is a schematic diagram showing still another example of the arrangement of the exhaust gas separation device 11. In FIG. 13, the solid-line arrows schematically show the pipes through which the gas passes. One solid line may indicate a single pipe or a plurality of pipes. The decontamination device 12, the gas treatment device 21, and the pipes are the same as those shown in FIG. 10. In the example shown in FIG. 13, a valve 31 is provided at the collective portion of the pipes from each gas treatment device 21, and two pipes are provided from this valve 31 toward the exhaust gas separation device 11. One of the two pipes is a supply line, and the other pipe is a discharge line. A valve 32 is provided in the supply line, and a valve 33 is provided in the discharge line. By operating the three valves 31 to 33, each gas treatment device 21 can be connected to the exhaust gas separation device 11.

[0059] For example, the valve 31 may be normally closed, and the valves 32 and 33 may be normally open so that the exhaust gas from each gas treatment device 21 always passes through the exhaust gas separation device 11. The valve 31 may be closed and the valves 32 and 33 may be opened only during the time period when the amount of exhaust gas from each gas treatment device 21 increases so that the exhaust gas from each gas treatment device 21 passes through the exhaust gas separation device 11. Note that the path switching unit using the valves 31 to 33 can also be provided in a pipe other than the collective portion of the pipes. For example, a path switching unit may be provided at at least one of the arrangement positions A1, A2, A4 to A6 shown in FIG. 10.

[0060] In addition, the path switching unit using the valves 31 to 33 is also applicable to the one-to-one connection form, the one-to-many connection form, and the many-to-many connection form described with reference to FIG. 9. For example, in the one-to-one connection form, the one-to-many connection form, and the many-to-many connection form, a path switching unit using the valves 31 to 33 may be provided for at least one pipe as needed. Furthermore, in the one-to-one connection mode, one-to-many connection mode, and many-to-many connection mode, the pipe connecting the gas treatment device 21 and the decontamination device 12 can be composed of a normal line and a standby line. In this case, a path switching section using valves 31 to 33 may be provided for each of the normal line and the standby line. Specifically, a path switching section is provided at the collective portion of the pipes of the normal line, and similarly, a path switching section is provided at the collective portion of the pipes of the standby line. During normal operation, the normal line is used, and the normal line is connected to the exhaust gas separation device 11 as necessary. During maintenance of the normal line, the standby line is used, and the standby line is connected to the exhaust gas separation device 11 as necessary.

[0061] Furthermore, in the one-to-one connection mode, one-to-many connection mode, and many-to-many connection mode, a part of the pipe connecting the gas treatment device 21 and the decontamination device 12 may have a pipe structure in which a plurality of pipes are connected in parallel. In this case, a path switching section using valves 31 to 33 may be provided for each pipe of the pipe structure. Specifically, the collective portion of the pipes from each gas treatment device 21 may be the above pipe structure, and a path switching section may be provided for each pipe of this pipe structure. Also, in the one-to-one connection mode, one-to-many connection mode, and many-to-many connection mode, the exhaust gas separation device 11 is preferably arranged for the gas treatment device 21 in which the amount of a specific substance contained in the first gas 22a among the plurality of gas treatment devices 21 is large. As described above, by applying the present technology, it is possible to reduce the plant cost, the amount of chemicals, and the amount of waste of the decontamination device 12 and the wastewater treatment facility 13. At the same time, the amount of CO 2 emissions can also be reduced by these activities.

[0062] (Other Embodiments) Both of the above-described exhaust gas treatment systems 10 and 10A can be realized by incorporating the exhaust gas separation device 11 into an existing exhaust gas treatment system. Here, the Reform method of using the exhaust gas treatment system in which the decontamination device 12 and the exhaust gas separation device 11 are combined will be described.

[0063] In this other embodimentReform The method involves an exhaust gas treatment system comprising a decontamination device 12 that receives exhaust gas containing a specific substance and makeup water, burns the exhaust gas to decontaminate the specific substance, and discharges wastewater in which the decontaminated specific substance is dissolved in the makeup water; and wastewater treatment equipment 13 that receives the wastewater, removes the specific substance from the wastewater, and recovers the wastewater with the specific substance removed as the makeup water. Reform The method includes providing an exhaust gas separation device 11 that receives a first gas 22a containing the specific substance, recovers a part of the specific substance contained in the first gas 22a, and discharges a second gas 22b having a lower content of the specific substance than the first gas 22a as the exhaust gas to the decontamination device 12. The recovery rate of the specific substance of the exhaust gas separation device 11 is set such that the supply amount per unit time of the specific substance supplied to the decontamination device 12 is less than the treatment amount per unit time of the specific substance processed by the decontamination device 12.

[0064] According to the above method of incorporating the exhaust gas separation device, even if the amount of the specific substance contained in the exhaust gas increases, the specific substance can be decontaminated without changing existing equipment such as the discharge equipment of the decontamination device 12 and the recovery equipment of the wastewater treatment equipment 13. The following specifically explains this effect.

[0065] The case where the specific substance is fluorine will be described as an example. Assuming that the supply amount of fluorine is 2,000 kg / d and the maximum treatment amount of fluorine in the decontamination device 12 is 1,000 kg / d. In this case, if the recovery rate of fluorine of the exhaust gas separation device 11 incorporated in the front stage of the decontamination device 12 is set to 50%, fluorine can be removed by the decontamination device 12 without changing the existing equipment. In other words, the equipment to be expanded as the supply amount of fluorine increases can be reduced so that it can be handled by the existing equipment, or it is possible to cope with the increased load on the manufacturing side without enhancing the wastewater treatment equipment and / or the wastewater discharge equipment. Some or all of the above embodiments may be described as follows in the following supplementary notes, but are not limited thereto. (Supplementary Note 1) Receives a first gas containing a specific substance, separates a part of the specific substance contained in the first gas, and discharges a second gas having a lower content of the specific substance than the first gas, an exhaust gas separation unit; A solubilization unit that treats the second gas to solubilize the specific substance; A dissolution unit that dissolves the solubilized specific substance in supply water and discharges first drainage water; An exhaust gas treatment system, comprising: a drainage treatment facility that receives the first drainage water, removes the specific substance from the first drainage water, and recovers the drainage water from which the specific substance has been removed as makeup water for the supply water. (Appendix 2) The drainage treatment facility is configured to discharge second drainage water containing the specific substance removed from the first drainage water; The exhaust gas treatment system according to Appendix 1, further comprising a water treatment device that receives the second drainage water and performs water treatment to remove the specific substance from the second drainage water. (Appendix 3) The first gas is a gas generated in one or both of a thin film formation process and a dry etching process. The exhaust gas treatment system according to Appendix 1 or 2. (Appendix 4) An exhaust gas treatment system according to any one of Appendices 1 to 3, wherein a decontamination device including the solubilization unit and the dissolution unit communicates with a gas treatment device that discharges the first gas via the exhaust gas separation unit. (Appendix 5) A plurality of the decontamination devices and a plurality of the gas treatment devices are respectively arranged, and the plurality of decontamination devices and the plurality of gas treatment devices are connected in any one of one-to-one, one-to-many, many-to-one, and many-to-many connection forms, or in a combination of two or more connection forms; The exhaust gas separation unit is incorporated in a pipe through which the gas containing the specific substance provided inside at least one of the plurality of gas treatment devices flows, or a pipe through which the gas containing the specific substance extending outside from the gas treatment device flows. The exhaust gas treatment system according to Appendix 4. (Appendix 6) The pipes extend from the plurality of the gas treatment devices respectively, and the exhaust gas separation unit is incorporated in an assembly portion of the pipes from each gas treatment device. The exhaust gas treatment system according to appended note 5. (Appended note 7) The exhaust gas treatment system according to any one of appended notes 1 to 6, wherein the specific substance contains at least one component of fluorine, nitrogen, carbon, and silicon and one or both of compounds of the component. (Appended note 8) A step of receiving a first gas containing a specific substance, separating a part of the specific substance contained in the first gas, and discharging a second gas having a lower content of the specific substance than the first gas; A step of treating the second gas to solubilize the specific substance; A step of dissolving the solubilized specific substance in supply water and discharging first drainage water; A step of receiving the first drainage water, removing the specific substance from the first drainage water, and recovering the drainage water from which the specific substance has been removed as makeup water for the supply water. An exhaust gas treatment method including the steps. (Appended note 9) A decontamination device that treats exhaust gas containing a specific substance to solubilize the specific substance, and dissolves the solubilized specific substance in supply water to discharge first drainage water, and receives the first drainage water, and removes the specific substance from the first drainage water. A method for modifying an exhaust gas treatment system including a drainage treatment facility that recovers the drainage water from which the specific substance has been removed as makeup water for the supply water, A method for modifying an exhaust gas treatment system, comprising providing an exhaust gas separation device that receives a first gas containing the specific substance, separates a part of the specific substance contained in the first gas, and discharges a second gas having a lower content of the specific substance than the first gas as the exhaust gas to the decontamination device. (Appended note 10) The recovery rate of the specific substance of the exhaust gas separation device is set so that the supply amount per unit time of the specific substance supplied to the decontamination device is less than the treatment amount per unit time of the specific substance treated by the decontamination device. The method for modifying an exhaust gas treatment system according to appended note 9.

[0066] The present invention has been described with reference to the embodiments, but the present invention is not limited to the above embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

[0067] This application claims priority based on Japanese Patent Application No. 2023-201755 filed on November 29, 2023, and incorporates the entire disclosure thereof herein.

Explanation of Reference Numerals

[0068] 10 Exhaust gas treatment system 11 Exhaust gas separation device 12 Decontamination device 13 Wastewater treatment facility 22a First gas 22b Second gas 23a First wastewater 24 Makeup water

Claims

1. an exhaust gas separation unit that receives a first gas containing a specific substance, separates a portion of the specific substance contained in the first gas, and discharges a second gas having a content of the specific substance less than that of the first gas; a solubilizing unit that processes the second gas to solubilize the specific substance; a dissolving section that dissolves the solubilized specific substance in supply water and discharges a first wastewater; a wastewater treatment facility that receives the first wastewater, removes the specific substance from the first wastewater, and recovers the wastewater from which the specific substance has been removed as make-up water for the supply water, An exhaust gas treatment system, wherein a portion of the specific substances separated by the exhaust gas separation section includes a component that is to be solubilized by the solubilization section.

2. The wastewater treatment facility is configured to discharge a second wastewater containing the specific substance removed from the first wastewater; The exhaust gas treatment system according to claim 1 , further comprising a water treatment device that receives the second wastewater and performs water treatment to remove the specific substance from the second wastewater.

3. 3. The exhaust gas treatment system according to claim 1, wherein the first gas is a gas generated in one or both of a thin film formation process and a dry etching process.

4. 3. The exhaust gas treatment system according to claim 1, wherein a detoxification device including the solubilization section and the dissolution section communicates with a gas treatment device that discharges the first gas through the exhaust gas separation section.

5. A plurality of the abatement devices and a plurality of the gas treatment devices are arranged, and the plurality of the abatement devices and the plurality of the gas treatment devices are connected in any one of a one-to-one, one-to-many, many-to-one, and many-to-many connection form, or in a combination of two or more connection forms; The exhaust gas treatment system according to claim 4, wherein the exhaust gas separation unit is incorporated in a piping through which a gas containing the specific substance flows that is provided inside at least one of the plurality of gas treatment devices, or in a piping through which a gas containing the specific substance flows that extends from the gas treatment device to the outside.

6. 6. The exhaust gas treatment system according to claim 5, wherein the pipes extend from each of the plurality of gas treatment devices, and the exhaust gas separation unit is incorporated in a joint portion of the pipes from the respective gas treatment devices.

7. The exhaust gas treatment system according to claim 1 or 2, wherein the specific substance includes at least one component selected from the group consisting of fluorine, nitrogen, carbon, and silicon, and / or a compound of the component.

8. An exhaust gas separation section that receives a first gas containing a specific substance, separates a portion of the specific substance contained in the first gas, and discharges a second gas having a content of the specific substance less than that of the first gas; a solubilizing unit that processes the second gas to solubilize the specific substance; a dissolving section that dissolves the solubilized specific substance in supply water and discharges a first wastewater; a wastewater treatment facility that receives the first wastewater, removes the specific substance from the first wastewater, and recovers the wastewater from which the specific substance has been removed as make-up water for the supply water, a detoxification device including the solubilization unit and the dissolution unit communicates with a gas treatment device that discharges the first gas through the exhaust gas separation unit; A plurality of the abatement devices and a plurality of the gas treatment devices are arranged, and the plurality of the abatement devices and the plurality of the gas treatment devices are connected in any one of a one-to-one, one-to-many, many-to-one, and many-to-many connection form, or in a combination of two or more connection forms; An exhaust gas treatment system, wherein the exhaust gas separation unit is incorporated in a piping through which a gas containing the specific substance flows that is provided inside at least one of the multiple gas treatment devices, or in a piping through which a gas containing the specific substance flows that extends from the gas treatment device to the outside.

9. receiving a first gas containing a specific substance, separating a portion of the specific substance contained in the first gas, and discharging a second gas having a content of the specific substance less than that of the first gas; treating the second gas to solubilize the specific substance; A step of dissolving the solubilized specific substance in supply water and discharging a first wastewater; receiving the first wastewater, removing the specific substance from the first wastewater, and recovering the wastewater from which the specific substance has been removed as make-up water for the supply water; A method for treating an exhaust gas, wherein a portion of the specific substances to be separated includes a component to be solubilized.

10. A method for remodeling an exhaust gas treatment system including: a detoxification device that treats exhaust gas containing specific substances to solubilize the specific substances, dissolves the solubilized specific substances in supply water, and discharges first wastewater; and a wastewater treatment facility that receives the first wastewater, removes the specific substances from the first wastewater, and recovers the wastewater from which the specific substances have been removed as make-up water for the supply water, comprising: an exhaust gas separation device that receives a first gas containing the specific substance, separates a portion of the specific substance contained in the first gas, and discharges a second gas having a lower content of the specific substance than the first gas as the exhaust gas to the abatement device; A method for retrofitting an exhaust gas treatment system, wherein a portion of the specific substances to be separated includes the components to be solubilized.

11. The method for modifying an exhaust gas treatment system as described in claim 10, wherein the recovery rate of the specific substance in the exhaust gas separation device is set so that the amount of the specific substance supplied to the decontamination device per unit time is less than the amount of the specific substance treated by the decontamination device per unit time.

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