Organic Solvent Recovery System

Abstract

An organic solvent recovery system according to the present invention comprises an organic solvent recovery apparatus for performing an adsorption treatment to adsorb an organic solvent in a gas to be treated in a plurality of first treatment tanks connected in a series multi-stage configuration and a desorption treatment in one of the first treatment tanks that is selected therefrom sequentially, and an organic solvent concentrator apparatus for performing an adsorption and desorption treatment and a desorption treatment in a second treatment tank, wherein the desorption treatments in the selected one of the first treatment tanks and the second treatment tank are initiated at the same time.

Description

[Technical Field]

[0001] The present invention relates to an organic solvent recovery system for recovering an organic solvent from an organic solvent-containing gas. [Background technology]

[0002] As a system for recovering an organic solvent from an organic solvent-containing gas, for example, Patent Document 1 discloses a gas treatment device equipped with three treatment tanks containing adsorbents. In this gas treatment device, an adsorption process is carried out continuously in two treatment tanks, while a desorption process is carried out in the remaining treatment tank. A dilution gas is supplied to dry the adsorbent in the treatment tank after the desorption process.

[0003] Patent Document 2 discloses an organic solvent recovery system including a first adsorption / desorption device having two treatment tanks and a second adsorption / desorption device that recovers organic solvents contained in the gas to be treated discharged from the first adsorption / desorption device. The second adsorption / desorption device has a first treatment section that adsorbs organic solvents contained in the gas to be treated using a second adsorption / desorption element, and a second treatment section that desorbs the organic solvents adsorbed to the second adsorption / desorption element from the second adsorption / desorption element.

[0004] In the gas treatment device described in Patent Document 1, the adsorption process is carried out continuously in two treatment tanks, thereby increasing the removal rate of the organic solvent. In the organic solvent recovery system described in Patent Document 2, the adsorption process is carried out continuously in one of the treatment tanks of the first adsorption / desorption device and the first treatment section of the second adsorption / desorption device, thereby increasing the removal rate of the organic solvent. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-147863 [Patent Document 2] Japanese Patent Publication No. 2014-240052 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, there has been a need to further increase the removal rate of organic solvents in organic solvent recovery systems. In response to this need, the present inventors have developed a method for recovering organic solvents by combining the two treatment methods described in Patent Document 1. We investigated a system in which an adsorption process is carried out continuously in a tank, and then an adsorption process is further carried out using a second adsorption / desorption device described in Patent Document 2, and the gas containing the organic solvent desorbed from the second adsorption / desorption device is returned to the gas to be treated (raw gas) in the treatment tank.

[0007] However, in the system considered above, the gas to be treated that is discharged from the treatment tank of the first adsorption / desorption device and supplied to the second adsorption / desorption device is contaminated for several tens of seconds with steam mist (hereinafter referred to as white smoke) that is generated immediately after switching between the adsorption process and the desorption process in the treatment tank. When high-temperature, high-humidity gas containing white smoke is supplied to the second adsorption / desorption device in an adsorbed state (i.e., after the adsorption process in the second adsorption / desorption device has been completed to some extent), the increase in the gas temperature and the adsorption of moisture into the second adsorption / desorption device slow down the adsorption rate of the organic solvent, resulting in the discharge of organic solvent gas at a concentration greater than the designed outlet concentration of the second adsorption / desorption device. Furthermore, the adsorption of moisture by the white smoke also increases the thermal energy required for the desorption process in the second adsorption / desorption device.

[0008] To address the impact of this white smoke, we considered cooling or dehumidifying the gas to be treated supplied to the second adsorption / desorption unit, but this would increase cooling costs.We also considered increasing the length of the adsorbent layer to address the slower adsorption rate, but this would increase the amount of adsorbent required, resulting in an increase in the size of the unit.

[0009] In view of the above problems, the present invention has an object to provide an organic solvent recovery system that can reduce costs, size, and energy consumption. [Means for solving the problem]

[0010] As a result of extensive research, the present inventors have found that the above problems can be solved by the following means, and have arrived at the present invention. That is, the present invention has the following configuration. 1. A system including three or more first treatment tanks filled with a first adsorbent capable of adsorbing and desorbing an organic solvent, a water vapor supply flow path for introducing water vapor, a connecting flow path for connecting a plurality of the first treatment tanks in series in multiple stages, and a treated gas supply flow path for supplying a treated gas containing an organic solvent; an organic solvent recovery apparatus in which, among all of the first treatment tanks, a plurality of the first treatment tanks connected in series in multiple stages perform an adsorption treatment of the organic solvent contained in the gas to be treated supplied thereto and discharge the first treatment gas, and in the remaining first treatment tanks, a desorption treatment of the adsorbed organic solvent is performed using the introduced steam, and all of the first treatment tanks switch between the adsorption treatment and the desorption treatment and continuously perform the same; an organic solvent concentration device including a second treatment tank filled with a second adsorbent capable of adsorbing and desorbing an organic solvent, and a feed flow path for supplying the first treatment gas to the second treatment tank, and which alternately performs adsorption treatment and desorption treatment of the organic solvent contained in the first treatment gas, An organic solvent recovery system characterized in that the first treatment tank and the second treatment tank are switched between desorption treatment and adsorption treatment simultaneously. 2. The organic solvent recovery system described in 1 above, characterized in that it is provided with a dilution gas supply flow path that supplies dilution gas to the connecting flow path, and a return flow path that returns desorbed gas discharged by the desorption process in the second treatment tank to the dilution gas supply flow path. 3. An organic solvent recovery system as described in 1 or 2 above, comprising a connecting flow path for introducing a portion of the second treatment gas discharged by adsorption treatment in the second treatment tank for desorption treatment in the second treatment tank, and a heating means provided in the connecting flow path. 4. An organic solvent recovery system according to any one of items 1 to 3 above, characterized in that the second adsorbent is made of a material containing at least one of granular activated carbon, activated carbon fiber, and zeolite. 5. The organic solvent recovery system according to any one of claims 1 to 4, characterized in that heated air is used for the desorption treatment of the second adsorbent. [Effects of the Invention]

[0011] According to the present invention, by simultaneously switching between desorption and adsorption treatments in the treatment tanks of the upstream organic solvent recovery device and the downstream organic solvent concentration device, it is possible to ensure a layer length of the adsorbent that is not saturated with organic solvent, in response to a decrease in adsorption rate due to moisture adsorption caused by white smoke entering the downstream organic solvent concentration device. This prevents the organic solvent from mixing with the treated gas (clean gas) treated and discharged from the organic solvent concentration device. Furthermore, by introducing white smoke early in the adsorption process of the organic solvent concentration device, the time required to dry the adsorbent by aeration of the treated gas after the white smoke has subsided is maximized, making it possible to reduce the energy required for desorption treatment more than with conventional techniques. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram showing a configuration of an organic solvent recovery system according to an embodiment of the present invention. [Figure 2] 1 is a table showing the concentration of an organic solvent (dichloromethane) in the gas to be treated, the removal rate of the organic solvent (dichloromethane), and the amounts of cooling water and steam utilities used in Examples and Comparative Examples. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG.

[0014] (Embodiment 1) 1 is a diagram schematically illustrating the configuration of an organic solvent recovery system 1 according to one embodiment of the present invention. The organic solvent recovery system 1 includes an organic solvent recovery apparatus 100 and an organic solvent concentration apparatus 200. The system also includes a feed flow path L300 and a return flow path L400.

[0015] In the organic solvent recovery system 1, the organic solvent is removed and recovered from a gas to be treated containing the organic solvent in the organic solvent recovery apparatus 100, and then the organic solvent is further removed and concentrated from the first treated gas discharged from the organic solvent recovery apparatus 100 in the organic solvent concentrating apparatus 200, and a second treated gas (clean gas) is discharged. Furthermore, the desorbed gas desorbed from the organic solvent concentrating apparatus 200 is returned to the organic solvent recovery apparatus 100 through the return flow path L400. In the organic solvent recovery system 1, the desorption treatment (desorption step) and the adsorption treatment (adsorption step) are simultaneously switched in each treatment tank of the organic solvent recovery apparatus 100 and the organic solvent concentrating apparatus 200. "Simultaneously" includes "almost simultaneously."

[0016] Each component of the organic solvent recovery system 1 will be described below.

[0017] The organic solvent recovery apparatus 100 is an apparatus for removing and recovering an organic solvent from a gas to be treated. The gas to be treated is supplied to the organic solvent recovery apparatus 100 from a gas to be treated supply source provided outside the system of the organic solvent recovery apparatus 100. The organic solvent recovery apparatus 100 includes three first treatment tanks 101-103, a gas to be treated supply flow path L110, connecting flow paths L121-L123, extraction flow paths L131-L133, steam supply flow paths L141-L143, organic solvent recovery flow paths L151-L153, ​​a separator 120, a re-supply flow path L160, and a diluent gas supply flow path L170.

[0018] The first treatment tanks 101 to 103 each have a first adsorbent 101A to 103A capable of adsorbing and desorbing organic solvents. , Ha Examples of materials include coma-shaped activated carbon, zeolite, activated carbon fiber, etc., but activated carbon fiber is preferred. Each of the first treatment tanks 101-103 has an open / close damper V101-V103 that switches between supplying and not supplying the gas to be treated to the gas to be treated supply port, and an open / close damper V104-V106 that switches between discharging and not discharging the treated gas from the outlet port after passing through the first adsorbent 101A-103A.

[0019] In each of the first treatment tanks 101 to 103, adsorption of the organic solvent by the first adsorbents 101A to 103A and desorption of the organic solvent from the first adsorbents 101A to 103A are alternately performed. That is, in one of the three first treatment tanks 101 to 103, a first adsorption step (adsorption treatment) is performed in which the organic solvent is adsorbed from the gas to be treated supplied from the gas to be treated supply source and a first post-adsorption gas is discharged, and in another first treatment tank connected in series to the first treatment tank where the first adsorption treatment is performed, a second adsorption step (adsorption treatment) is performed in which the organic solvent is adsorbed from the first post-adsorption gas and a first treatment gas is discharged, and during this time, a desorption step (desorption treatment) is performed in the remaining one of the first treatment tanks. In each of the first treatment tanks 101 to 103, 1st adsorption step , second adsorption step, Desorption process are switched repeatedly in this order.

[0020] The treated gas supply flow path L110 is a flow path for supplying the treated gas to each of the first treatment tanks 101 to 103. The upstream end of the treated gas supply flow path L110 is connected to a treated gas supply source. The treated gas supply flow path L110 is provided with a cooler C1 and a heater H1 for adjusting the temperature and humidity of the treated gas flowing into each of the first treatment tanks 101 to 103.

[0021] The treated gas supply flow path L110 has branch flow paths L111 to L113 that supply the treated gas to each of the first treatment tanks 101 to 103. The branch flow path L111 is provided with an on-off valve V111. The branch flow path L112 is provided with an on-off valve V112. The branch flow path L113 is provided with an on-off valve V113.

[0022] Each connecting flow path L121 to L123 is connected so that the gas to be treated after the organic solvent has been adsorbed in the first adsorbent of one of the three first treatment tanks 101 to 103 (the first treatment tank used in the first adsorption step) is introduced into the gas to be treated supply port of another first treatment tank (the treatment tank used in the second adsorption step) different from the one of the three first treatment tanks 101 to 103.

[0023] The connecting channels L121 to L123 join together. Merging route The first connecting flow path L121 has an on-off valve V121 at a position where it branches off again from the merging path L120. The second connecting flow path L122 has an on-off valve V122 at a position where it branches off again from the merging path L120. The third connecting flow path L123 has an on-off valve V123 at a position where it branches off again from the merging path L120.

[0024] The extraction flow paths L131 to L133 are for removing the adsorbed water from the first treatment tanks 101 to 103. These are flow paths for extracting a first processing gas, which is a processing gas. The extraction flow paths L131 to L133 are connected to the processing gas outlets of the first processing tanks 101 to 103, respectively. The first extraction flow path L131 is provided with an on-off valve V131. The second extraction flow path L132 is provided with an on-off valve V132. The third extraction flow path L133 is provided with an on-off valve V133. The extraction flow paths L131 to L133 have a confluence flow path L130 where they converge with each other.

[0025] The water vapor supply channels L141 to L143 are channels for supplying water vapor to the first treatment tanks 101 to 103, for desorbing the organic solvents adsorbed in the first adsorbents 101A to 103A from the first adsorbents 101A to 103A.

[0026] The first water vapor supply passage L141 connects the water vapor supply source and the first treatment tank 101, and is provided with an on-off valve V141. The second water vapor supply passage L142 connects the water vapor supply source and the first treatment tank 102, and is provided with an on-off valve V142. The third water vapor supply passage L143 connects the water vapor supply source and the first treatment tank 103, and is provided with an on-off valve V143.

[0027] The organic solvent recovery flow paths L151 to L153 are flow paths for recovering water vapor (desorbed gas) containing the organic solvent desorbed from the first adsorbents 101A to 103A. Each of the organic solvent recovery flow paths L151 to L153 is connected to each of the first treatment tanks 101 to 103. The organic solvent recovery flow paths L151 to L153 merge with each other. Confluent flow path The confluence flow path L150 is provided with a condenser 122. The condenser 122 condenses the desorbed gas by cooling the desorbed gas flowing through the confluence flow path L150, and discharges the condensed liquid (a mixture of water produced by the condensation of the desorbed gas and the liquid-phase organic solvent).

[0028] The separator 120 is provided downstream of the condenser 122 and separates the incoming condensate into a liquid phase of separated wastewater and a liquid phase of recovered solvent. The recovered solvent is removed from the organic solvent recovery system 100. A space (vent gas) containing a trace amount of organic solvent is formed above the separator 120.

[0029] The re-supply flow path L160 connects the separator 120 and the treated gas. supply This is a flow path that connects to the flow path L110. The vent gas in the separator 120 is supplied again to each of the first treatment tanks 101 to 103 through the re-supply flow path L160 and the treated gas supply flow path L110.

[0030] The wastewater treatment facility 500 is a facility for removing organic solvents contained in the separated wastewater. Exclusion Supplied from the aqueous phase and separated Exclusion The organic solvent is removed from the water, and the treated water is discharged outside the system. For example, the wastewater treatment facility 500 may be an aeration facility that aerates the separated wastewater to volatilize the organic solvent contained in the separated wastewater and separate the separated wastewater into an aeration gas containing the organic solvent and treated water. The aeration gas is supplied through an aeration gas supply line L 1 The aeration gas supply passage L110 is connected to the upstream side of the cooler C1 through the aeration gas supply passage L61. 1 61 may be provided with a dehumidifying means for removing moisture from the aeration gas.

[0031] The dilution gas supply passage L170 supplies a dilution gas to the connecting passage L110 for accelerating the drying of the first adsorbents 101A to 103A after the desorption step. 1 21~L 1 23. The dilution gas is composed of a gas containing at least one of outside air, instrument air, nitrogen gas, and argon gas.

[0032] The organic solvent concentrating apparatus 200 is equipment that further removes organic solvent from the first process gas discharged from the organic solvent recovery apparatus 100. The organic solvent concentrating apparatus 200 has at least two or more second process tanks. To explain two cases, the second process tanks 201 and 202 have second adsorbents 201A and 202A that can adsorb the organic solvent contained in the first process gas discharged through the junction flow path L130. In the second process tank 201, the second adsorbent 201A adsorbs the organic solvent contained in the first process gas, while the second process tank 202 desorbs the organic solvent in the first process gas that has been adsorbed by the second adsorbent 202A. The second process tanks 201 and 202 alternate between the adsorption process and the desorption process and perform these processes in sequence. By passing the first treated gas through the second treatment tank, it is possible to discharge a second treated gas, which is a clean gas from which the organic solvent has been further removed, and after adsorption is completed, a heated gas with a smaller flow rate than the first treated gas is passed through to desorb the organic solvent adsorbed by the adsorbent, thereby discharging a desorbed gas in which the organic solvent is concentrated. The desorbed gas is returned to the organic solvent recovery device 100 through the dilution gas supply flow path L170 connected to the return flow path L400.

[0033] The second treatment tanks 201 and 202 each have a second adsorbent 201A, 202A capable of adsorbing and desorbing organic solvents. , Ha Nikam Condition The second treatment tanks 201 and 202 are provided with an open / close damper V201, V202 for switching between supplying and not supplying the gas to be treated to the gas supply port, and an open / close damper V203 for switching between discharging and not discharging the gas to be treated from the outlet port after passing through the second adsorbent 201A, 202A. 3 , V204 It has the following characteristics.

[0034] The feed flow path L300 is a flow path for feeding the gas to be treated from the organic solvent recovery device 100 to the organic solvent concentrating device 200. The feed flow path L300 is provided with a flow control device for controlling the temperature and humidity of the first treated gas to be introduced into the organic solvent concentrating device 200. Adjustment A cooler C2 and a heater H2 are provided for this purpose.

[0035] The return flow path L400 is a flow path for returning the desorbed gas from the organic solvent concentrating device 200 to the organic solvent recovery device 100. The return flow path L400 is connected to the dilution gas supply flow path L170.

[0036] The organic solvent concentrating device 200 discharges the second treated gas discharged from the second treatment tanks 201 and 202 to the outside through a clean gas discharge flow path L220. The organic solvent concentrating device 200 also has a connection flow path L230 and a heater H3.

[0037] The connection flow path L230 connects the clean gas discharge flow path L220 and the second treatment tanks 201 and 202, and a part of the second treatment gas is used for desorption. Note that the outside air may also be used for desorption.

[0038] Regarding the damper control required for switching between the treatment tanks of the organic solvent recovery device 100 and the organic solvent concentration device 200, an appropriate device is provided as needed.

[0039] The organic compounds contained in the gas to be treated by the organic solvent recovery system 1 of this embodiment are not particularly limited, but include aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, and acrolein, ketones such as methyl ethyl ketone, diacetyl, methyl isobutyl ketone, and acetone, 1,4-dioxane, 2-methyl-1,3-dioxolane, 1,3-dioxolane, tetrahydrofuran, methyl acetate, ethyl acetate, and acetic acid. acidExamples include esters such as propyl acetate and butyl acetate, alcohols such as ethanol, n-propyl alcohol, isopropyl alcohol, and butanol, glycols such as ethylene glycol, propylene glycol, diethylene glycol, and triethylene glycol, organic acids such as acetic acid and propionic acid, phenols, aromatic organic compounds such as toluene, xylene, and cyclohexane, ethers such as diethyl ether and allyl glycidyl ether, nitriles such as acrylonitrile, chlorine-containing organic compounds such as dichloromethane, 1,2-dichloroethane, trichloroethylene, and epichlorohydrin, and organic compounds such as N-methyl-2-pyrrolidone, dimethylacetamide, and N,N-dimethylformamide. The gas to be treated may contain one or more of these. [Example]

[0040] The organic solvent recovery system 1 of the present invention explained in the above embodiment will be further described in detail using the following examples, although the present invention is not limited to the following examples.

[0041] [Example 1] The following treatment was carried out using the organic solvent recovery system 1 shown in FIG. 1 described above. Activated carbon fibers were used for the first adsorbents 101A, 102A, and 103A and the second adsorbents 201A and 202A of the organic solvent concentration device 200. charcoal The amount of activated carbon fiber used in the second adsorbent 201A and 202A was 3.8 kg / tank. charcoal The amount of fiber was 3.7 kg per tank. As an example of the gas to be treated, a gas containing 26,000 ppm of dichloromethane as an organic solvent at 25°C was used. The air volume was 5.3 Nm 3 / min, the design concentration of dichloromethane discharged outside the organic solvent recovery system was set to 5 ppm or less.

[0042] First, in the organic solvent recovery device 100 covered Processing gas flow rate: 5.3 Nm 3The first adsorption step outlet gas discharged from the first treatment tank 101 was then sent as a second adsorption inlet gas to the first treatment tank 102, which was in the second adsorption step. At this time, the second adsorption inlet gas was sent at a flow rate of 9.5 Nm 3 The dilution gas and desorption gas were used to adjust the temperature to 45°C / min. The gas treated in the first treatment tank 102 was discharged as the first treatment gas and sent to the organic solvent concentrating device 200 through the feed flow path L300. When the dichloromethane concentration in the first adsorption step outlet gas discharged from the first treatment tank 101 reached 100 ppm, the steps were switched.

[0043] While the first treatment tank 101 was performing the first adsorption step and the first treatment tank 102 was performing the second adsorption step, water vapor was introduced into the first treatment tank 103 to perform the desorption step. At this time, white smoke was present for one minute immediately after switching the adsorption tanks, and the first treatment gas had a temperature of 60°C and a humidity of 100%. After one minute had passed, the dichloromethane concentration in the first treatment gas was 100 ppm, the gas temperature was 45°C, and the humidity was 55%. It was.

[0044] The first treated gas discharged from the organic solvent recovery device 100 was passed through the feed line L300 to the second treatment tank 201, where an adsorption step was carried out, and the second treated gas (cleaned gas) was discharged. Connection channel Heater H3 from L230 to 130℃ Canada The gas was heated and supplied to the second treatment tank 202, and the desorbed gas was discharged. The entire amount of the desorbed gas was supplied to the dilution gas supply line L170 of the organic solvent recovery unit 100 through the return line L400. Here, each of the organic solvent concentrating devices 200 2 The process switching of the treatment tank is performed at each stage of the organic solvent recovery apparatus 100. 1This was done simultaneously with the process switching in the treatment tanks. To explain using a specific example, the following were done simultaneously: switching from the desorption process to the first adsorption process in the first treatment tank 101, switching from the first adsorption process to the second adsorption process in the first treatment tank 102, switching from the second adsorption process to the desorption process in the first treatment tank 103, switching from the adsorption process to the desorption process in the second treatment tank 201, and switching from the desorption process to the adsorption process in the second treatment tank 202. Each switching was done simultaneously.

[0045] In Example 1, the dichloromethane removal rate was 99%, the cooling water utility consumption was 0, and the steam consumption was 4 kg / hr.

[0046] [Comparative Example 1] The same gas to be treated as in Example 1 was treated in the organic solvent recovery system 100 and the organic solvent concentrating system 200 in the same manner as in Example 1. In Comparative Example 1, the process switching in each first treatment tank of the organic solvent recovery system 100 was performed 7 minutes after the start of the adsorption process in the organic solvent concentrating system 200, and the organic solvent concentrating system 200 was operated so as to switch between processes when the dichloromethane concentration in the adsorption process outlet gas reached 5 ppm. In Comparative Example 1, in order to achieve performance equivalent to that of Example 1, i.e., to achieve an outlet gas concentration of 5 ppm or less at a removal rate of 99%, it was necessary to cool and dehumidify the white smoke to 50°C to suppress the effect of the white smoke.

[0047] In Comparative Example 1, the dichloromethane removal rate was 99%. Rejection Water utility usage is 0.3 m 3 / hr, water vapor Utility usage was 5.3 kg / hr.

[0048] The dichloromethane concentration and removal rate in the gas to be treated and the amount of cold water utility used in Example 1 and Comparative Example 1 are shown in FIG.

[0049] The above findings reveal the following: In Example 1, unlike Comparative Example 1, simultaneous process switching in each treatment tank ensures a layer length of the adsorbent that is not saturated with organic solvent, thereby preventing a decrease in the adsorption rate due to moisture adsorption caused by the inflow of white smoke. This makes it possible to suppress the emission of organic solvents in the treated gas into the treated gas due to the influence of white smoke without cooling the white smoke. Furthermore, by introducing white smoke early in the start of the adsorption process in organic solvent concentration device 200, the time available for drying the adsorbent by ventilating the treated gas after the white smoke has subsided is maximized, which indicates that the energy required for desorption can be reduced more than in conventional technology.

[0050] The above-disclosed embodiments, modifications, and examples are all illustrative and not restrictive. Furthermore, appropriate combinations of the embodiments, modifications, and examples are also included within the scope of the present invention. In other words, the technical scope of the present invention is defined by the claims, and includes all changes, modifications, and substitutions within the meaning and scope of the claims. [Industrial Applicability]

[0051] The organic solvent recovery system of the present invention can reduce the cooling costs for preventing white smoke and the amount of water vapor required for desorption compared to conventional systems by linking the process switching between the treatment tank of the organic solvent recovery device and the treatment tank of the organic solvent concentration device, thereby making a great contribution to the industrial world. [Explanation of symbols]

[0052] 1: Organic solvent recovery system 100: Organic solvent recovery device 101 to 103: First treatment tank 101A~103A: 1st adsorbent 110: Supply channel 120: Separator 200: Organic solvent concentrator 201, 202: Second treatment tank 201A, 202A: second adsorbent 500: Wastewater treatment equipment H1~H3: Heater C1, C2: Cooler L110: Processing gas supply flow path L121~L123: Connecting flow path L130: Confluence channel L131~L133: Extraction flow path L140: Water vapor supply channel L151 to L153: Organic solvent recovery flow path L160: Resupply channel L170: Dilution gas supply line L230: Connection channel L300: Feed channel L400: Return flow path V111-V113, V121-V123, V131-V133, V141-V143: On-off valves V101~V106, V201~V203: Open / close damper

Claims

1. The system comprises three or more first treatment tanks filled with a first adsorbent capable of adsorbing and desorbing an organic solvent, a water vapor supply flow path for introducing water vapor, a connecting flow path for connecting the plurality of first treatment tanks in series in multiple stages, and a treated gas supply flow path for supplying a treated gas containing an organic solvent, an organic solvent recovery apparatus in which, among all of the first treatment tanks, a plurality of the first treatment tanks connected in series in multiple stages perform an adsorption treatment of the organic solvent contained in the gas to be treated supplied thereto and discharge the first treatment gas, and in the remaining first treatment tanks, a desorption treatment of the adsorbed organic solvent is performed using the introduced steam, and all of the first treatment tanks switch between the adsorption treatment and the desorption treatment and continuously perform the same; an organic solvent concentration device including a second treatment tank filled with a second adsorbent capable of adsorbing and desorbing an organic solvent, and a feed flow path for supplying the first treatment gas to the second treatment tank, and which alternately performs adsorption treatment and desorption treatment of the organic solvent contained in the first treatment gas, An organic solvent recovery system characterized in that the first treatment tank and the second treatment tank are simultaneously switched between desorption treatment and adsorption treatment.

2. a dilution gas supply flow path for supplying a dilution gas to the connecting flow path; 2. The organic solvent recovery system according to claim 1, further comprising a return flow path for returning desorbed gas discharged by the desorption treatment in the second treatment tank to the dilution gas supply flow path.

3. 3. The organic solvent recovery system according to claim 1, further comprising: a connecting flow path for introducing a portion of the second treatment gas discharged by the adsorption treatment in the second treatment tank for desorption treatment in the second treatment tank; and a heating means provided in the connecting flow path.

4. 4. The organic solvent according to claim 1, wherein the second adsorbent is made of a material containing at least one of granular activated carbon, activated carbon fiber, and zeolite. Collection system.

5. 5. The organic solvent recovery system according to claim 1, wherein heated air is used for desorption of the second adsorbent.

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