Exhaust gas treatment system, exhaust gas treatment method, and method for modifying exhaust gas treatment system

Abstract

An exhaust gas treatment system 10 comprises: 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 in which the content of the specific substance is smaller than that of the first gas 22a; a detoxifying device 12 that treats the second gas 22b to solubilize the specific substance, dissolves the solubilized specific substance into supplied water, and discharges a first discharge water 23a; and a discharge water treatment facility 13 that receives the first discharge water 23a, removes the specific substance from the first discharge water 23a, and recovers the discharge water from which the specific substance has been removed as supplemental water for the supplied water.

Description

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

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

[0002] Various gases, including perfluorocarbon (PFC) gases, are used in the manufacturing processes of semiconductors, liquid crystal displays, light-emitting diodes (LEDs), solar cells, etc. For example, in semiconductor manufacturing plants, CF4, SF6, CHF3, etc. are used in dry etching processes, and NF3, C2F6, C3F8, etc. are used in thin-film formation processes such as chemical vapor deposition (CVD), generating exhaust gases containing these PFC gases. PFC gases are harmful and also greenhouse gases.

[0003] Known examples of equipment for treating exhaust gases containing PFC gases and the like include exhaust gas treatment equipment (abatement devices) that treat exhaust gases by combustion abatement or the like (see, for example, Patent Document 1, etc.).Furthermore, known are wastewater treatment equipment that treats wastewater from the exhaust gas treatment equipment and returns it to the exhaust gas treatment equipment (see, for example, Patent Document 2, etc.).

[0004] JP 2022-72981 A JP 2022-70609 A

[0005] In recent years, the amount of gas used in semiconductor manufacturing processes has been increasing due to the miniaturization and multi-layering of semiconductor devices. Accordingly, the amount of hazardous substances that need to be decomposed (or removed) has also increased. As a result, the scale of exhaust gas treatment facilities and wastewater treatment facilities has increased, leading to increased plant and operating costs.

[0006] An object of the present invention is to provide an exhaust gas treatment system, an exhaust gas treatment method, and an improvement method for an exhaust gas treatment system that can suppress the increase in the scale of exhaust gas treatment equipment and wastewater treatment equipment and suppress increases in plant costs and operating costs.

[0007] In order to achieve the above-mentioned object, according to one aspect of the present invention, an exhaust gas treatment system is provided, which includes 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 lower content of the specific substance than the first gas; a solubilization unit that processes 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 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.

[0008] According to another aspect of the present invention, there is provided an exhaust gas treatment method including the steps of 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 lower content of the specific substance than the first gas; treating the second gas to solubilize the specific substance; dissolving the solubilized specific substance in supply water and discharging first wastewater; and 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.

[0009] According to yet another aspect of the present invention, there is provided a method for modifying 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, wherein the method includes providing an exhaust gas separation device that receives the first gas containing the specific substances, separates some of the specific substances contained in the first gas, and discharges a second gas, which has a lower content of the specific substances than the first gas, as the exhaust gas to the detoxification device.

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

[0011] FIG. 1 is a schematic diagram showing an exhaust gas treatment system according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing an example of an abatement device in the exhaust gas treatment system shown in FIG. 1. FIG. 3 is a schematic diagram showing an example of a wastewater treatment facility in the exhaust gas treatment system shown in FIG. 1. FIG. 4 is a schematic diagram showing an exhaust gas treatment system of a comparative example. FIG. 5 is a schematic diagram showing an example of a fluorine-based emission device in the exhaust gas treatment system shown in FIG. 5. FIG. 6 is a schematic diagram showing an example of a total exhaust emission device in the exhaust gas treatment system shown in FIG. 5. FIG. 7 is a schematic diagram showing an exhaust gas treatment system of a comparative example. FIG. 8 is a schematic diagram for explaining a connection form between an abatement device and a gas treatment device. FIG. 9 is a schematic diagram showing an example of the arrangement of an exhaust gas separation device. FIG. 10 is a schematic diagram showing another example of the arrangement of an exhaust gas separation device. FIG. 11 is a schematic diagram showing yet another example of the arrangement of an exhaust gas separation device.

[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.

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

[0014] In this embodiment, the flue gas separation apparatus 11 and the abatement apparatus 12 are installed in a manufacturing building 20. The manufacturing building 20 is provided with a plurality of gas treatment apparatuses 21 that discharge a first gas 22a containing a specific substance. The abatement apparatus 12 is in communication with at least one of the gas treatment apparatuses 21 via the flue gas separation apparatus 11. In this embodiment, the abatement apparatus 12 is in communication with a gas treatment apparatus 21 that performs a thin film formation process and a gas treatment apparatus 21 that performs a dry etching process via the flue gas separation apparatus 11. The thin film formation process may include, for example, a CVD process, but is not limited to this.

[0015] In the dry etching process, PFC gases such as CF4, SF6, and CHF3 are used, and in the thin film formation process, PFC gases such as NF3, C2F6, and C3F8, and SiH ４ and NH ３ , SiH ２ CL ２ Semiconductor material gases such as TEOS (tetraethoxysilane) are used. For cleaning the inside of the gas processing equipment, NF ３ and CL ２ Gases such as these are used. The gas processing device 21 discharges a first gas 22a containing these gases. Gases not used in the reaction are discharged together with gases used in the reaction and decomposed (HF, CO2, decomposition gases, etc.). In each gas processing device 21, a vacuum pump, for example, may be used to discharge the first gas 22a. In this case, a large amount of nitrogen (N2) gas may be introduced to protect equipment downstream of the vacuum pump or for safety purposes. Here, the first gas 22a contains a specific substance. The specific substance may include one or both of fluorine (F) and a fluorine compound. The specific substance may also include one or both of nitrogen (N) and a nitrogen compound. Note that the specific substance is not limited to fluorine and a fluorine compound or nitrogen and a fluorine compound. For example, the specific substance may include other components or compounds thereof, such as a carbon source (C), chlorine (Cl), or silicon (Si). In other words, a particular substance may contain at least one of fluorine, nitrogen, carbon, and silicon and / or a compound of said element.

[0016] The exhaust gas separation device 11 receives a first gas 22a discharged from each of the gas treatment device (film formation device) 21 and the gas treatment device (dry etching) 21. The first gas 22a may contain decomposition products or by-products of the gas discharged from the gas treatment device 21. The exhaust gas separation device 11 separates a portion 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. In this embodiment, the specific substance is assumed to be fluorine and / or compounds thereof, and the exhaust gas separation device 11 separates and recovers a portion 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 resource.

[0017] The flue gas separation device 11 may have any configuration as long as it can recover a specific substance (here, fluorine) from the first gas 22a. Common gas recovery technologies include cryogenic distillation, which separates substances based on differences in boiling points; pressure swing adsorption (PSA) and temperature swing adsorption (TSA), which repeat adsorption and desorption; and membrane separation, which uses a gas separation membrane. Any one of these gas recovery technologies, or a combination of these, may be applied to the flue gas separation device 11.

[0018] When a specific substance is separated and recovered in the flue gas separation apparatus 11, the recovery rate R1 of the specific substance can be set to a theoretically or practically possible value depending on the substance to be recovered and the recovery method. For example, in this embodiment, the specific substance is fluorine, and the flue gas separation apparatus 11 is configured so that the fluorine recovery rate R1 is 50%. Here, the fluorine recovery rate R1 indicates the recovery rate relative to the total fluorine load when, for example, the first gas 22a is a mixed gas of NF, CF, SF, etc.

[0019] The detoxification device 12 receives feed water containing makeup water 24 from the wastewater treatment facility 13 and the second gas 22b discharged by the exhaust gas separation device 11. The detoxification device 12 combusts the second gas 22b to detoxify hazardous substances including specific substances, and discharges wastewater in which components derived from the decomposed hazardous substances have been dissolved in the feed water. Here, fluorine is assumed to be the specific substance, and therefore the detoxification device 12 discharges first wastewater 23a in which fluorine has been dissolved in the feed water.

[0020] The configuration of the detoxification device 12 will be described in detail. FIG. 2 is a schematic diagram showing one configuration example of the detoxification device 12. In FIG. 2, solid arrows schematically indicate pipes through which liquids flow, and dashed arrows typically indicate pipes through which gases flow. Referring to FIG. 2, the detoxification device 12 has a solubilization section 121 and a dissolution section 122. The solubilization section 121 processes the second gas 22b to solubilize specific substances. The dissolution section 122 dissolves the specific substances solubilized in the solubilization section 121 into supply water 25, and discharges the first wastewater 23a. The supply water 25 may include makeup water 24.

[0021] The solubilization unit 121 may include a combustion chamber in which combustion treatment is performed using, for example, a burner. 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 supply water 25 including makeup water 24. The water used for cooling is discharged as 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 with the dissolved specific substances is discharged from the bottom of the scrubber as first wastewater 23a.

[0022] The solubilization section 121 and the dissolving section 122 may be the same device. The combination of the combustion chamber that constitutes the solubilization section 121 and the scrubber that constitutes the dissolving section 122 is not limited to the above. For example, a scrubber may be provided on each of the inlet and outlet sides of the combustion chamber. A smoke washing chamber that sprays water on the gas may be provided between the combustion chamber and the scrubber. The abatement device 12 may be an existing abatement device that removes specific substances using, for example, electric heating or plasma. A detailed description of such abatement devices will be omitted, but devices with a general configuration can be used.

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

[0024] FIG. 3 shows an example of a 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 (UF) device 135, an intermediate tank 136, a reverse osmosis (RO) membrane filtration device 137, and a makeup water tank 138. The first wastewater 23a discharged from the detoxification device 12 is stored in the raw water tank 130 as water to be treated. The raw water tank 130 and the heat exchanger 131 are connected via piping, and a pump 139a is provided on this piping. The heat exchanger 131 and the neutralization tank 132 are connected via piping. The neutralization tank 132 and the biological reaction tank 133 are connected via piping. The biological reaction tank 133 and the intermediate tank 134 are connected via piping. The intermediate tank 134 and the UF 135 are connected via a pipe. The UF 135 and the intermediate tank 136 are connected via a pipe. The intermediate tank 136 and the RO 137 are connected via a pipe, and a pump 139b is provided on this pipe. The RO 137 and the make-up water tank 138 are connected via a pipe. A discharge pipe is connected to the make-up water tank 138, and a pump 139c is provided on 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 make-up water tank 138 in that order at an appropriate time.

[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 nutrients. The biological reaction tank 133 performs biological treatment. The biological reaction tank 133 is equipped with a mechanism for aerating the water to be treated (an air bubbling mechanism for supplying the 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 multiple UF membranes with fine pores. The filtered water from the UF 135 is stored in the intermediate tank 136, and then a dispersant and slime control agent are added before being supplied to the RO 137. The RO 137 further filters the filtered water from the UF 135 using multiple RO membranes. The filtered water (permeate) from the RO 137 is stored in the makeup water tank 138. The water stored in the makeup water tank 138 is charged with NaCLO, and is then discharged as makeup water 24 and supplied to the detoxification device 12. The concentrated water separated in the UF 135 and RO 137 is discharged as second wastewater 23b.

[0026] According to the exhaust gas treatment system 10 of the present embodiment described above, the exhaust gas separation device 11 separates a portion of the specific substances (components such as fluorine) contained in the first gas 22a, thereby reducing the cooling energy required for the abatement device 12. As a result, it is possible to prevent the abatement device 12 and the wastewater treatment facility 13 from becoming larger in scale, and to prevent increases in plant costs and operating costs. Below, this effect will be specifically described using a comparative example.

[0027] Comparative Example 1 FIG. 4 is a schematic diagram showing an exhaust gas treatment system of Comparative Example 1. The exhaust gas treatment system 100 of Comparative Example 1 differs from the exhaust gas treatment system 10 of this embodiment in that it does not include the exhaust gas separation device 11. The configuration of the exhaust gas treatment system 100 is basically the same as that of the exhaust gas treatment system 10, except for the exhaust gas separation device 11. In the exhaust gas treatment system 100, the first gas 22a discharged from each gas treatment device 21 is supplied directly to the detoxification device 12. Therefore, compared to a configuration including the exhaust gas separation device 11, the amount of harmful substances to be detoxified (or decomposed) is greater, which increases the heat generation amount of the detoxification device 12 and the amount of supply water 25 required for cooling. As a result, the amount of first wastewater 23a from the detoxification device 12 increases, which requires larger-scale drainage equipment and recovery equipment, resulting in increased plant costs and operating costs.

[0028] The above problem will be specifically explained assuming that fluorine (F) is a specific substance contained in the exhaust gas. In the exhaust gas treatment system 100, the amount of fluorine in the first gas 22a supplied to the abatement device 12 per day is, for example, 2,000 kg / d. The abatement device 12 consumes the thermal energy required to treat 2,000 kg / d of fluorine, and uses the amount of feed water 25 corresponding to the amount of heat generated. If the amount of first wastewater 23a discharged from the abatement device 12 per day is 20,000 m3, the amount of fluorine in the first gas 22a is 2,000 kg / d. 3 / d. The amount of fluorine contained in the first wastewater 23a per day is 2,000 kg / d. Note that the first wastewater 23a also contains components other than fluorine. The F concentration of the second wastewater 23b is, for example, 2,000 mg / L.

[0029] In contrast, in the exhaust gas treatment system 10 of this embodiment, the stage exhaust gas separation device 11 recovers a portion of the fluorine contained in the first gas 22a. Here, since the fluorine recovery rate R1 is 50%, if it is assumed that the amount of fluorine in the first gas 22a per day is 2,000 kg / d, the amount of fluorine in the second gas 22b supplied to the abatement device 12 per day is 1,000 kg / d. The abatement device 12 consumes the thermal energy required to treat 1,000 kg / d of fluorine, and uses the amount of feed water 25 corresponding to the amount of heat generated. The amount of this feed water 25 can be reduced compared to Comparative Example 1. Specifically, the amount of first wastewater 23a discharged per day from the abatement device 12 is 20,000 m3 in Comparative Example 1. 3 / d, 15,000 m 3 / d.

[0030] As described above, the exhaust gas treatment system 10 of this embodiment can reduce the amount of first wastewater 23a discharged by the detoxification device 12 and the amount of fluorine contained in the first wastewater 23a, compared to Comparative Example 1. This allows the scale of the detoxification device 12 and the wastewater treatment equipment 13 to be reduced, thereby reducing plant costs and operating costs. Here, reduced plant costs include reduced construction costs for the plant equipment and reduced installation space due to scale reduction. Furthermore, operating costs include energy costs related to operation, costs for chemicals such as neutralizing agents required to recover specific decomposed substances (components such as fluorine), and costs for treating waste such as sludge. Reduced operating costs include reduced chemical inputs and reduced energy costs (power consumption).

[0031] Furthermore, as the amount of hazardous substances to be decomposed (or decomposed) increases with an increase in the amount of exhaust gas, the energy consumption and heat generation of the decomposition device increase, and the amounts of make-up water required for cooling and for dissolving components derived from the hazardous substances increase. As a result, the wastewater volume and load of the decomposition device increase, the scale of the wastewater treatment facility increases, and plant costs and operating costs increase. According to the flue gas treatment system 10 of this embodiment, the discharge amount of the first wastewater 23a discharged from the decomposition device 12 and the amount of fluorine contained in the first wastewater 23a can be reduced. Therefore, even if the amount of hazardous substances to be decomposed (or decomposed) increases with an increase in the amount of exhaust gas, increases can be suppressed. As a result, increases in the wastewater volume and load of the decomposition device 12 and the scale of the wastewater treatment facility 13 can be suppressed, and increases in plant costs and operating costs can be suppressed.

[0032] 2, a reduction in the supply rate and load of the second gas 22b enables a reduction in energy consumption such as fuel and electricity for the burner of the solubilization section 121. A reduction in the supply rate (required amount) of the feed water 25 enables a reduction in the scale and capacity of supply equipment such as piping and feed pumps for supplying the feed water 25 to the dissolving section 122. A reduction in the flow rate of the second gas 22b enables a reduction in the scale of the solubilization section 121 and associated equipment, a reduction in the scale of the dissolving section 122 and associated equipment, and a reduction in the scale of supply equipment such as piping and feed pumps for draining the first drainage water 23a.

[0033] 3, the reduction in the volume of the first wastewater 23a allows 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 to be reduced in size, and the piping connecting these tanks can also be reduced in size. For example, in Comparative Example 1, the volume of the neutralization tank 132 was reduced to 209 m 3 , the volume of the biological reactor 133 is 834 m 3 In this case, in the exhaust gas treatment system 10 of this embodiment, the volume of the neutralization tank 132 is set to 157 m 3, the volume of the biological reactor 133 is set to 625 m 3 Furthermore, by reducing the amount of first wastewater 23a, it is possible to reduce the input (required amount) of cooling water, neutralizing agent, nutrients, dispersants, slime control agent, and NaCLO. Furthermore, by reducing the load of TOC (total organic carbon), a component contained in first wastewater 23a, it is possible to reduce the scale of the biological reaction tank 133.

[0034] Furthermore, due to the reduced load of silica (silicic acid) and solids contained in the first wastewater 23a, the number of UF membranes can be reduced, making it possible to reduce the scale of the UF 135. For example, in Comparative Example 1, if the UF 135 includes 223 UF membranes, the number of UF membranes in the UF 135 can be reduced to 150 in the exhaust gas treatment system 10 of this embodiment. Furthermore, due to the reduced load of components (ions) in the second wastewater 23b, the number of RO membranes can be reduced, making it possible to reduce the scale of the RO 137. For example, in Comparative Example 1, if the RO 137 includes 1,012 RO membranes, the number of RO membranes in the RO 137 can be reduced to 655 in the exhaust gas treatment system 10 of this embodiment.

[0035] Furthermore, the exhaust gas treatment system 10 of this embodiment can improve the water recovery rate R2 of the wastewater treatment equipment 13 compared to Comparative Example 1. For example, the water recovery rate R2 of the wastewater treatment equipment 13 may be rate-limiting due to CaF scale on the RO membrane concentration side. For example, assuming the same fluorine concentration on the RO membrane concentration side of 2000 mg / L, the water recovery rate R2 of the wastewater treatment equipment 13 is 95% in Comparative Example 1, while it is 97% in this embodiment. The water recovery rate R2 of the wastewater treatment equipment 13 varies depending on the fluorine recovery rate R1 of the exhaust gas separation device 11. Specifically, when the amount of wastewater from the detoxification device 12 is constant (when the amount of water supplied to the wastewater treatment equipment 13 is constant), the higher the fluorine recovery rate R1, the higher the water recovery rate R2. For example, when the fluorine recovery rate R1 is 70%, the water recovery rate R2 can be 98%. Table 1 shows the results of a comparison between this embodiment (fluorine recovery rates R1: 50% / 70%) and Comparative Example 1.

[0036] Second Embodiment Fig. 5 is a schematic diagram showing the configuration of an air pollution control system according to a second embodiment of the present invention. An air pollution control system 10A of this embodiment differs from the first embodiment in that it includes a water treatment device 16. The air pollution control system 11, the abatement device 12, and the wastewater treatment facility 13 are the same as those of the first embodiment, and therefore detailed description of these configurations will be 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 a specific substance from the second wastewater 23b. In this case, the specific substance is assumed to be fluorine, and the water treatment device 16 has a fluorine-based wastewater device 14 and a total wastewater treatment device 15.

[0038] The fluorine-based wastewater system 14 receives the second wastewater 23b and coagulates and precipitates the fluorine contained in the second wastewater 23b. FIG. 6 shows a specific configuration of the fluorine-based wastewater system 14. As shown in FIG. 6, the fluorine-based wastewater system 14 includes reaction tanks 140 and 141, a coagulation tank 142, a settling tank 143, and a dehydrator 144. The reaction tank 140 and the reaction tank 141 are connected via a pipe. The reaction tank 141 and the coagulation tank 142 are connected via a pipe. The coagulation tank 142 and the settling tank 143 are connected via a pipe. The settling tank 143 and the dehydrator 144 are connected via a pipe. The second wastewater 23b discharged from the wastewater treatment facility 13 is stored in the reaction tank 140. In the reaction tank 140, Ca(OH)2 (calcium hydroxide) is added as a neutralizing agent. The water to be treated, to which calcium hydroxide has been added, is stored in a reaction tank 141. PAC (polyaluminum chloride) and NaOH (sodium hydroxide) are added to the reaction tank 141. PAC is a flocculant that aggregates and precipitates suspended solids contained in the water to be treated. NaOH is an alkaline agent that adjusts the pH of the water to be treated.

[0039] The water stored in the reaction tank 141 is supplied to the settling tank 143 via the coagulation tank 142. In the coagulation tank 142, suspended solids contained in the water to be treated coagulate, and tiny lumps of flocs are precipitated. In the settling tank 143, the flocs are precipitated. The precipitates are supplied to the dehydrator 144, and the water to be treated from which the sediment has been removed is supplied as wastewater to the total wastewater treatment system 15. In the dehydrator 144, the precipitates are dehydrated and discharged as sludge. The coagulation and sedimentation method using calcium hydroxide has been described above, but a crystallization reaction apparatus for obtaining calcium fluoride crystals, as disclosed in Patent No. 5650164, for example, may also be used; the fluorine-based wastewater treatment system 14 is not limited to these types.

[0040] The total wastewater treatment system 15 receives wastewater discharged from the fluorine-based wastewater treatment system 14 and performs neutralization treatment on the wastewater. FIG. 7 shows a specific configuration of the total wastewater treatment system 15. As shown in FIG. 7, the total wastewater treatment system 15 has a reaction tank 150, a coagulation tank 151, and a flotation separation tank 152. The reaction tank 150 and the coagulation tank 151 are connected via piping. The coagulation tank 151 and the flotation separation tank 152 are also connected via piping. Wastewater discharged from the settling tank 143 of the fluorine-based wastewater treatment system 14 is stored in the reaction tank 150. PAC and NaOH are added to the reaction tank 150. The stored water in the reaction tank 150 is supplied to the flotation separation tank 152 via the coagulation tank 151. In the coagulation tank 151, suspended solids contained in the water to be treated coagulate, resulting in the precipitation of flocs. The flotation separation tank 152 is a solid-liquid separation tank. In the flotation tank 152, pressurized water with gas dissolved under pressure is injected from the bottom of the tank, and the air bubbles attach to the flocs, giving them buoyancy and causing them to float up and separate. The clean water stored in the bottom of the flotation tank 152 is discharged as flotation-separated water. The flotation-separated water can be discharged into rivers or the ocean, for example, or it can be reused as recovered water.

[0041] According to the exhaust gas treatment system 10A of the present embodiment described above, the exhaust gas separation device 11 recovers a portion of the specific substance contained in the first gas 22a, thereby simultaneously achieving a reduction in the cooling energy required for the abatement 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, the scale of the equipment for the water treatment device 16 can be reduced, and plant costs and operating costs can be reduced. In addition, the amount of sludge generated by fluorine coagulation and sedimentation can be reduced. These effects will be specifically described below using a comparative example.

[0042] (Comparative Example 2) Fig. 8 is a schematic diagram showing an exhaust gas treatment system of Comparative Example 2. The exhaust gas treatment system 100A of Comparative Example 2 differs from the exhaust gas treatment system 10A of the present embodiment in that it does not include the exhaust gas separation device 11. The configuration of the exhaust gas treatment system 100A, 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 amount of second wastewater 23b discharged per day from the wastewater treatment facility 13 is set to, for example, 1,000 m 3 / d. The amount of fluorine contained in the second wastewater 23b per day is 2,000 kg / d. The fluorine-based wastewater treatment device 14 subjects the 2,000 kg / d of fluorine to coagulation and sedimentation treatment, and removes it as 8.4 tons of sludge material. The amount of wastewater discharged per day from the fluorine-based wastewater treatment device 14 is assumed to be 880 m 3 The amount of wastewater to be treated by the total wastewater treatment system 15 is assumed to be 880 m 3 Assume that / d.

[0044] According to the exhaust gas treatment system 10A of this embodiment, the amount of second wastewater 23b discharged per day from the wastewater treatment facility 13 is increased by 1,000 m3 in Comparative Example 2. 3 500m from / d 3 / d. In addition, the amount of fluorine contained in the second wastewater 23b per day 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 performs coagulation and sedimentation treatment of 1,000 kg / d of fluorine, and as a result, the amount of sludge can be reduced from 8.4 t in Comparative Example 2 to 4.2 t. In addition, the amount of wastewater discharged per day by the fluorine-based wastewater treatment device 14 can be reduced from 880 m3 in Comparative Example 2 to 1,000 m3. 3 / d 440m 3 / d, and the amount of wastewater treated by the total wastewater treatment system 15 can be reduced to 880 m3 in Comparative Example 2. 3 / d 440m 3 / d.

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

[0046] Specifically, in the fluorine-based wastewater treatment system 14 shown in Fig. 6, the reduction in the amount of water and the amount of fluorine in the second wastewater 23b makes it possible to reduce the scale of each of the reaction tanks 140, 141, coagulation tank 142, settling tank 143, and dehydrator 144, and also makes it possible to reduce the scale of the piping connecting these. For example, in Comparative Example 2, the volume of the reaction tank 140 is reduced to 11 m 3 , the volume of the reaction vessel 141 is 11 m 3 , the volume of the coagulation tank 142 is set to 4 m 3 , the area of ​​the settling tank 143 is 4 m 2 , the membrane area of ​​the dehydrator 144 is 56 m 2 In this case, in the exhaust gas treatment system 10A of this embodiment, the volume of the reaction tank 140 is set to 6 m 3 , the volume of the reaction vessel 141 is set to 6 m 3 , the volume of the coagulation tank 142 is set to 2 m 3 , the area of ​​the settling tank 143 is 2 m 2 , the membrane area of ​​the dehydrator 144 is 28 m 2 By reducing these facilities, plant costs can be reduced by approximately 50%.

[0047] In Comparative Example 2, when the input rates of Ca(OH)2 are 4,200 kg / d, PAC 300 kg / d, and NaOH (caustic soda) 163 kg / d, the exhaust gas treatment system 10A of this embodiment can reduce the input rates of Ca(OH)2 to 2,100 kg / d, PAC 151 kg / d, and NaOH 82 kg / d. Furthermore, in the total wastewater treatment system 15 shown in FIG. 7, the reduction in the amount of water and fluorine in the second wastewater 23b allows the scales of the reaction tank 150, coagulation tank 151, and flotation separation tank 152 to be reduced, and the scale of the piping connecting these tanks can also be reduced. For example, in Comparative Example 2, when the volume of the reaction tank 150 is reduced to 10 m 3 , the volume of the coagulation tank 151 is set to 4 m 3 , the area of ​​the flotation separation tank 152 is set to 2 m 2 In this case, in the exhaust gas treatment system 10A of this embodiment, the volume of the reaction tank 150 is set to 5 m 3 , the volume of the coagulation tank 151 is set to 2 m 3 , the area of ​​the flotation separation tank 152 is 1 m 2 By reducing the amount of equipment, the plant cost can be reduced by approximately 50%. Furthermore, in Comparative Example 2, when the PAC input amount is 264 kg / d and the NaOH input amount is 143 kg / d, in the exhaust gas treatment system 10A of this embodiment, the PAC input amount can be reduced to 133 kg / d and the NaOH input amount can be reduced to 72 kg / d.

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

[0049] The first and second embodiments described above are merely examples of the present invention, and each component of the exhaust gas treatment system 10 (10A) can be modified as appropriate within the scope of not interfering with the effects described in each embodiment. In the first and second embodiments described above, the abatement device 12 and the gas treatment device 21 may be connected in one of one-to-one, one-to-multiple, many-to-one, and many-to-multiple connection configurations, or in a combination of two or more connection configurations, and the exhaust gas separation device 11 may be incorporated into at least one of the gas treatment device 21.

[0050] FIG. 9 is a schematic diagram illustrating the connection between the decontamination device 12 and the gas treatment device 21. In FIG. 9, solid arrows schematically represent pipes through which gas passes, and each solid line may represent either a single pipe or multiple pipes. As shown in FIG. 9( a), the decontamination device 12 and the gas treatment device (film formation device) 21 are arranged in a multi-to-multiple connection, and the decontamination device 12 and the gas treatment device (dry etching device) 21 are also arranged in a multi-to-multiple connection. In the multi-to-multiple connection between the decontamination device 12 and the gas treatment device (film formation 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 formation device) 21. For example, the exhaust gas separation device 11 may be provided for each gas treatment device (film formation device) 21 or each decontamination device 12, or may be provided in a collection section to which two or more gas treatment devices (film formation devices) 21 are connected, or in a collection section to which two or more decontamination devices 12 are connected. Similarly, in a multiple-to-multiple connection configuration between the abatement devices 12 and the gas treatment devices (dry etching) 21, the exhaust gas separation device 11 may be provided anywhere in the communication pipe connecting the abatement devices 12 and the gas treatment devices (dry etching) 21. For example, the exhaust gas separation device 11 may be provided for each gas treatment device (dry etching) 21, or may be provided at a junction where two or more gas treatment devices (dry etching) 21 are connected.

[0051] 9( b), the detoxification device 12 and the gas treatment device (film formation device) 21 are arranged in a one-to-one connection configuration, and the detoxification device 12 and the gas treatment device (dry etching) 21 are also arranged in a one-to-one connection configuration. In this case, the exhaust gas separation device 11 may be provided for at least one gas treatment device (film formation device) 21. Similarly, the exhaust gas separation device 11 may be provided for at least one gas treatment device (dry etching) 21.

[0052] As shown in FIG. 9( c), the abatement apparatus 12 and the gas treatment apparatus (film formation apparatus) 21 are arranged in a many-to-one connection configuration, and the abatement apparatus 12 and the gas treatment apparatus (dry etching) 21 are also arranged in a many-to-one connection configuration. In the many-to-one connection configuration between the abatement apparatus 12 and the gas treatment apparatus (film formation apparatus) 21, the exhaust gas separation apparatus 11 may be provided anywhere in the communication pipe connecting the abatement apparatus 12 and the gas treatment apparatus (film formation apparatus) 21. For example, the exhaust gas separation apparatus 11 may be provided for each abatement apparatus 12, or may be provided in a junction where two or more abatement apparatuses 12 are connected. Similarly, in the many-to-one connection configuration between the abatement apparatus 12 and the gas treatment apparatus (dry etching) 21, the exhaust gas separation apparatus 11 may be provided anywhere in the communication pipe connecting the abatement apparatus 12 and the gas treatment apparatus (dry etching) 21. For example, the exhaust gas separation apparatus 11 may be provided for each abatement apparatus 12, or may be provided in a junction where two or more abatement apparatuses 12 are connected.

[0053] 9, the abatement device 12 and the gas treatment device (film formation device) 21 may be arranged in a one-to-many connection configuration. Similarly, the abatement device 12 and the gas treatment device (dry etching) 21 may be arranged in a one-to-many connection configuration. In any of the connection configurations, the exhaust gas separation device 11 may be provided for at least one gas treatment device 21. Furthermore, the connection configuration between the abatement device 12 and the gas treatment device (film formation device) 21 and the gas treatment device (dry etching) 21 may be a combination of two or more of the four connection configurations: one-to-one, one-to-many, many-to-one, and many-to-many. In this case, too, the exhaust gas separation device 11 may be provided for at least one gas treatment device 21. Furthermore, in each of the connection configurations described above, the exhaust gas separation device 11 may be incorporated into at least one gas treatment device 21.

[0054] An example of the arrangement of the exhaust gas separation device 11 will be described in detail below. FIG. 10 is a schematic diagram showing an example of the arrangement of the exhaust gas separation device 11. In FIG. 10, solid arrows schematically indicate pipes through which gas flows, and one solid line may indicate either a single pipe or multiple pipes. In the example shown in FIG. 10, two abatement devices 12 and three gas treatment devices 21 are connected in a multi-to-multiple configuration. The gas treatment devices 21 can be film deposition devices or dry etching devices. Arrangement positions A1 to A6 indicate possible arrangement positions for the exhaust gas separation device 11. Arrangement positions A1 and A2 indicate arrangement of two abatement devices 12 on the gas supply pipes, respectively. Arrangement position A3 indicates arrangement at a joint of pipes from each gas treatment device 21. Arrangement positions A4 to A6 indicate arrangement of pipes from each gas treatment device 21, respectively.

[0055] The flue gas separation device 11 may be installed at any of the installation positions A1 to A6. The flue gas separation device 11 may also be installed at two or more of the installation positions A4 to A6. The flue gas separation device 11 may also be installed at both the installation positions A1 and A2. There may be two or more gas treatment devices 21, and in this case, the flue gas separation device 11 may be installed for one or more gas treatment devices 21. There may also be three or more abatement devices 12, and in this case, the flue gas separation device 11 may be installed for one or more abatement 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, solid arrows schematically show the piping through which gas passes. In the example shown in FIG. 11, arrangement positions A1 to A9 of the exhaust gas separation device 11 relative to one gas processing device (film formation device) 21 are shown. The gas processing device (film formation device) 21 includes four chambers 21a. A pump 30 is provided on the piping on the discharge side of each chamber 21a. The piping on the discharge side of each pump 30 merges into one. Arrangement position A1 indicates an arrangement at a junction of piping from each pump. Arrangement positions A2 to A5 indicate an arrangement on the piping on the discharge side of each pump 30. Arrangement positions A6 to A9 indicate an arrangement on the piping on the discharge side of each chamber 21a. The exhaust gas separation device 11 may be provided at any of arrangement positions A1 to A9. Furthermore, the exhaust gas separation device 11 may be provided at two or more of arrangement positions A2 to A5. Furthermore, the exhaust gas separation device 11 may be provided at two or more locations among the locations A6 to A9. Note that there may be two or more chambers 21a. 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 yet another example of the arrangement of the exhaust gas separation device 11. In FIG. 12, solid arrows schematically indicate the piping through which gas passes. The chambers 21a, pumps 30, and piping are the same as those shown in FIG. 11. A valve 31 is provided in the piping from each pump 30, and two pipings are provided before and after this valve 31 toward the exhaust gas separation device 11. One of the two pipings 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. The supply lines are connected to a single line and connected to the exhaust gas separation device 11. The discharge lines are also connected to a single line and connected to the exhaust gas separation device 11. 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 a cleaning process is performed on each chamber 21a in sequence, the chamber 21a in which the cleaning process is performed is connected to the exhaust gas separation device 11. This allows for efficient recovery (separation) of exhaust gas. Furthermore, this arrangement allows for the lowest amount of exhaust gas and the highest concentration (load) of the gas to be treated compared to the arrangements shown in Figures 10 and 11, making it possible to downsize the recovery equipment and improve recovery efficiency. In the arrangement shown in Figure 12, a path switching unit using valves 31 to 33 may be provided in at least one chamber 21a. Furthermore, the number of chambers 21a is not limited to four. Two or more chambers 21a may be used.

[0058] FIG. 13 is a schematic diagram showing yet another example of the arrangement of the flue gas separation apparatus 11. In FIG. 13, solid arrows schematically indicate pipes through which gas passes, and one solid line may indicate a single pipe or multiple pipes. The abatement apparatus 12, gas treatment apparatus 21, and pipes are the same as those shown in FIG. 10. In the example shown in FIG. 13, a valve 31 is provided at the joint of the pipes from each gas treatment apparatus 21, and two pipes are provided from this valve 31 to the flue gas separation apparatus 11. One of the two pipes is a supply line, and the other is a discharge line. A valve 32 is provided on the supply line, and a valve 33 is provided on the discharge line. By operating the three valves 31 to 33, each gas treatment apparatus 21 can be connected to the flue gas separation apparatus 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 processing device 21 always passes through the exhaust gas separation device 11. Only during a time period when the amount of exhaust gas from each gas processing device 21 is large, the valve 31 may be closed and the valves 32 and 33 may be opened so that the exhaust gas from each gas processing device 21 always passes through the exhaust gas separation device 11. Note that the path switching unit using the valves 31 to 33 may also be provided in a pipe other than the piping assembly. For example, the path switching unit may be provided in at least one of the arrangement positions A1, A2, and A4 to A6 shown in FIG. 10 .

[0060] The path switching unit using the valves 31 to 33 can also be applied to the one-to-one connection, one-to-many connection, and many-to-many connection described with reference to FIG. 9 . For example, in the one-to-one connection, one-to-many connection, and many-to-many connection, a path switching unit using the valves 31 to 33 may be provided for at least one pipe, as necessary. Furthermore, in the one-to-one connection, one-to-many connection, and many-to-many connection, the pipe connecting the gas treatment device 21 and the abatement device 12 can be configured with a regular line and a backup line. In this case, a path switching unit using the valves 31 to 33 may be provided for each of the regular line and the backup line. Specifically, a path switching unit is provided at the junction of the regular line pipes, and similarly, a path switching unit is provided at the junction of the backup line pipes. During normal operation, the regular line is used, and the regular line is connected to the flue gas separation device 11 as needed. During maintenance of the regular line, the backup line is used, and the backup line is connected to the flue gas separation device 11 as needed.

[0061] Furthermore, in the one-to-one connection configuration, one-to-many connection configuration, and many-to-many connection configuration, a portion of the piping connecting the gas treatment device 21 and the abatement device 12 may be a piping structure in which multiple pipes are connected in parallel. In this case, a path switching unit using valves 31 to 33 may be provided for each pipe in the piping structure. Specifically, the collection portion of the pipes from each gas treatment device 21 may be configured as the above-mentioned piping structure, and each pipe in this piping structure may be provided with a path switching unit. Furthermore, in the one-to-one connection configuration, one-to-many connection configuration, and many-to-many connection configuration, it is preferable to arrange the flue gas separation device 11 for the gas treatment device 21 that contains a large amount of a specific substance in the first gas 22a among the multiple gas treatment devices 21. As described above, application of this technology enables reduction in plant costs for the abatement device 12 and the wastewater treatment facility 13, reduction in the amount of chemicals and waste, and at the same time, reduction in CO2 emissions from these activities.

[0062] (Other Embodiments) Either of the above-described exhaust gas treatment systems 10 and 10A can be realized by incorporating an exhaust gas separation device 11 into an existing exhaust gas treatment system. Here, a method for improving an exhaust gas treatment system using a combination of an abatement device 12 and an exhaust gas separation device 11 will be described.

[0063] The improvement method of this other embodiment is a method for improving an exhaust gas treatment system including a detoxification device (12) that receives exhaust gas containing specific substances and makeup water, combusts the exhaust gas to detoxify the specific substances, and discharges wastewater in which the detoxified specific substances have been dissolved in the makeup water, and a wastewater treatment facility (13) that receives the wastewater, removes the specific substances from the wastewater, and recovers the wastewater from which the specific substances have been removed as the makeup water, and includes providing an exhaust gas separation device (11) that receives a first gas (22a) containing the specific substances, recovers a portion of the specific substances contained in the first gas (22a), and discharges a second gas (22b) having a lower content of the specific substances than the first gas (22a) as the exhaust gas to the detoxification device (12). The recovery rate of the specific substances in the exhaust gas separation device (11) is set so that the amount of the specific substances supplied per unit time to the detoxification device (12) is smaller than the amount of the specific substances treated per unit time by the detoxification device (12).

[0064] According to the above-described method for incorporating an exhaust gas separation device, even if the amount of specific substances contained in the exhaust gas increases, the specific substances can be detoxified without modifying existing equipment such as the discharge equipment of the detoxification device 12 or the recovery equipment of the wastewater treatment equipment 13. This effect will be specifically described below.

[0065] An example will be described in which the specific substance is fluorine. Assume that the fluorine supply rate is 2,000 kg / d and the maximum fluorine treatment rate of the abatement device 12 is 1,000 kg / d. In this case, if the fluorine recovery rate of the exhaust gas separation device 11 installed upstream of the abatement device 12 is set to 50%, fluorine can be removed by the abatement device 12 without modifying the existing equipment. In other words, the equipment that would otherwise need to be expanded in response to an increase in the fluorine supply rate can be reduced so that it can be accommodated by the existing equipment, or it becomes possible to accommodate an increase in the production load without expanding the wastewater treatment equipment and / or wastewater treatment equipment. Some or all of the above-described embodiments can also be described as, but are not limited to, the following supplementary notes. (Supplementary Note 1) An exhaust gas treatment system comprising: 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 lower content of the specific substance than the first gas, a solubilization unit that processes 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 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. (Supplementary Note 2) The exhaust gas treatment system according to Supplementary Note 1, wherein the wastewater treatment facility is configured to discharge second wastewater containing the specific substance removed from the first wastewater, and further comprises a water treatment device that receives the second wastewater and performs water treatment to remove the specific substance from the second wastewater. (Supplementary Note 3) The exhaust gas treatment system according to Supplementary Note 1 or 2, wherein the first gas is a gas generated in one or both of a thin film formation process and a dry etching process. (Supplementary Note 4) The exhaust gas treatment system according to any one of Supplementary Notes 1 to 3, wherein a detoxification device including the solubilization section and the dissolution section communicates with a gas treatment device that discharges the first gas via the exhaust gas separation section.(Supplementary Note 5) The exhaust gas treatment system according to Supplementary Note 4, wherein 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 one-to-one, one-to-many, many-to-one, and many-to-many connection configurations, or in a combination of two or more connection configurations, and the exhaust gas separation unit is incorporated in a piping provided inside at least one of the plurality of gas treatment devices and through which a gas containing the specific substance flows, or in a piping extending from the gas treatment device to the outside and through which a gas containing the specific substance flows. (Supplementary Note 6) The exhaust gas treatment system according to Supplementary Note 5, wherein the piping extends from each of the plurality of gas treatment devices, and the exhaust gas separation unit is incorporated in a joint portion of the piping from the gas treatment devices. (Supplementary Note 7) The exhaust gas treatment system according to any one of Supplements 1 to 6, wherein the specific substance includes at least one component selected from the group consisting of fluorine, nitrogen, carbon, and silicon, and one or both of compounds of the component. (Supplementary Note 8) A method for treating an exhaust gas, comprising the steps of: 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 lower content of the specific substance than the first gas; treating the second gas to solubilize the specific substance; dissolving the solubilized specific substance in supply water and discharging first wastewater; and 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. (Supplementary Note 9) A method for modifying an exhaust gas treatment system comprising: 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, the method comprising providing an exhaust gas separation device that receives the first gas containing the specific substances, separates a portion of the specific substances contained in the first gas, and discharges a second gas, which has a lower content of the specific substances than the first gas, as the exhaust gas to the detoxification device.(Appendix 10) A method for modifying an exhaust gas treatment system as described in Appendix 9, 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.

[0066] Although the present invention has been described above with reference to the embodiments, 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 November 29, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0068] REFERENCE SIGNS LIST 10 Exhaust gas treatment system 11 Exhaust gas separation device 12 Harmful substance removal device 13 Wastewater treatment equipment 22a First gas 22b Second gas 23a First wastewater 24 Make-up water

Claims

1. An exhaust gas treatment system comprising: 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 lower content of the specific substance than the first gas; a solubilization section that processes the second gas to solubilize the specific substance; a dissolution section that dissolves the solubilized specific substance into supply water and discharges a first wastewater; and 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.

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

3. The exhaust gas treatment system according to claim 1 or 2, wherein the first gas is a gas generated in one or both of a thin film formation process and a dry etching process.

4. An exhaust gas treatment system as described in claim 1 or 2, wherein a decontamination device including the solubilization section and the dissolution section is connected via the exhaust gas separation section to a gas treatment device that discharges the first gas.

5. The exhaust gas treatment system according to claim 4, wherein 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 one-to-one, one-to-many, many-to-one, and many-to-many connection configurations, or in a combination of two or more connection configurations; and the exhaust gas separation unit is incorporated in a piping provided inside at least one of the plurality of gas treatment devices, through which gas containing the specific substance flows, or in a piping extending from the gas treatment device to the outside, through which gas containing the specific substance flows.

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

8. A method for treating exhaust gas comprising the steps of: 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 lower content of the specific substance than the first gas; treating the second gas to solubilize the specific substance; 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.

9. A method for modifying an exhaust gas treatment system comprising an abatement device that treats exhaust gas containing specific substances to solubilize the specific substances, dissolves the solubilized specific substances in supply water, and discharges a 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 providing an exhaust gas separation device that receives the first gas containing the specific substances, separates a portion of the specific substances contained in the first gas, and discharges a second gas having a lower content of the specific substances than the first gas as the exhaust gas to the abatement device.

10. A method for modifying an exhaust gas treatment system as described in claim 9, 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 abatement device per unit time is less than the amount of the specific substance treated by the abatement device per unit time.

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