JP2023156658A - Voc treatment device and method - Google Patents

Abstract

To save energy VOC removal treatment.SOLUTION: A VOC treatment method repeats the steps of: i) adsorbing VOC contained in a treated gas in a first adsorption material, adsorbing the VOC from a second adsorption material, and oxidizing the VOC in a platinum catalyst; ii) passing a heat recovery gas through the second adsorption material and the first adsorption material in this order, recovering heat from the second adsorption material, and preheating the first adsorption material using the recovered heat; iii) adsorbing the VOC contained in the treated gas in the second adsorption material, desorbing the VOC from the first adsorption material, and oxidizing the VOC with a platinum catalyst; and iv) passing the heat recovery gas through the first adsorption material and the second adsorption material in this order, recovering heat from the first adsorption material, and preheating the second adsorption material using the recovered heat.SELECTED DRAWING: Figure 1

Description

The present invention relates to an apparatus and method for adsorbing and removing VOCs contained in a gas to be treated.

VOC is an abbreviation for volatile organic compounds that easily volatilize into the atmosphere at room temperature and pressure. Typical VOCs include substances such as toluene, xylene, and ethyl acetate, which are contained in paints, printing inks, adhesives, cleaning agents, gasoline, thinners, and the like. VOCs in the atmosphere cause photochemical oxidants and suspended particulate matter (SPM) that cause photochemical smog. Therefore, measures are being taken to suppress VOC emissions from fixed sources such as factories.

Patent Document 1 discloses an adsorption device that adsorbs and removes components to be removed from a gas to be treated containing VOCs and the like. This adsorption device is equipped with two adsorption towers filled with adsorbent.One adsorption tower adsorbs the removed components in the gas to be treated, and at the same time, the other adsorption tower adsorbs the adsorbent. Configured for playback. By alternately switching between adsorption and regeneration of the adsorbent in the two adsorption towers, the gas to be processed can be continuously processed. A gas to be treated is introduced into an adsorption tower where adsorption is being performed, and a high-temperature carrier gas for regeneration is introduced into an adsorption tower where regeneration is being performed without introducing the gas to be processed. The carrier gas heats the adsorbent to a temperature at which the removed component is desorbed, is discharged from the adsorption tower together with the desorbed removed component (desorption gas), and is then cooled, and the removed component is condensed into a liquid and recovered.

Japanese Patent Application Publication No. 2004-25135

In recent years, there has been concern about the health effects of low concentrations of VOCs on the human body. Particularly in a closed space, the human body continues to be exposed to VOCs even at low concentrations, which has a large impact on the human body. Until now, VOC removal technology has been proposed to reduce VOCs emitted mainly from factories that use organic solvents, but as mentioned above, trace amounts of VOCs contained in the air (atmospheric gas) in closed spaces have been proposed. Technology for removing VOCs has not yet been developed.

As mentioned above, VOC removal technology for cleaning air containing trace amounts of VOCs requires efficient removal of low-concentration VOCs, maintenance-saving and long-term maintenance of good removal performance, and energy saving. This is strongly required compared to industrial applications.

The present invention has been made in view of the above circumstances, and its purpose is to propose a VOC treatment device and method for cleaning air (gas to be treated) containing VOC, which achieves energy saving.

A VOC treatment device according to one aspect of the present invention includes:
A first adsorption container and a second adsorption container filled with an adsorbent made of beta zeolite that adsorbs VOCs;
a first adsorption line that allows a gas to be treated containing VOC to flow from an inlet of the gas to be treated through the first adsorption container to an outlet of the treated gas;
a second adsorption line that allows the to-be-treated gas to flow from the to-be-treated gas inlet through the second adsorption container to the to-be-treated gas outlet;
a heater that heats the regeneration gas to the desorption temperature of the VOCs adsorbed on the adsorbent;
a platinum catalyst that oxidizes VOCs desorbed from the adsorbent and entrained in the regeneration gas;
a first regeneration loop that circulates the regeneration gas to the first adsorption vessel, the heater, and the platinum catalyst;
a second regeneration loop that circulates the regeneration gas to the second adsorption vessel, the heater, and the platinum catalyst;
a first heat recovery line that causes the heat recovery gas to flow through the first adsorption container and the second adsorption container in order to the treated gas outlet;
a second heat recovery line that causes the heat recovery gas to flow through the second adsorption container and the first adsorption container in order to the processing gas outlet;
an adsorption flow path switching device that selectively switches the flow path of the gas to be treated between the first adsorption line and the second adsorption line;
a regeneration flow path switching device that selectively switches the regeneration gas flow path between the first regeneration loop and the second regeneration loop;
a heat recovery flow path switching device that selectively switches the flow path of the heat recovery gas between the first heat recovery line and the second heat recovery line;
When the gas to be treated is flowing through the first adsorption line, the regeneration gas is circulated through the second regeneration loop, and when the gas to be treated is flowing through the second adsorption line, the regeneration gas is circulating through the second regeneration loop. The heat recovery gas circulates through the first regeneration loop, and while the flow of the gas to be treated is temporarily stopped and the flow path of the gas to be treated is switched from the first adsorption line to the second adsorption line, the heat recovery gas The heat recovery gas passes through the first heat recovery line while the flow of the process gas is temporarily stopped and the flow path of the process gas is switched from the second adsorption line to the first adsorption line. The present invention is characterized by comprising a control device that controls the operations of the adsorption channel switching device, the regeneration channel switching device, and the heat recovery channel switching device so as to flow.

Further, the VOC treatment method according to one aspect of the present invention uses a first adsorbent filled in a first adsorption container and a second adsorption material filled in a second adsorption container, both of which are made of beta-type zeolite. A VOC treatment method for removing VOCs in a gas to be treated, the method comprising:
i) Passing the gas to be treated through the first adsorption container to cause the first adsorbent to adsorb VOCs contained in the gas to be treated, and passing high-temperature regeneration gas through the second adsorption container to the second adsorption material. a step of desorbing VOCs from the adsorbent and oxidizing the VOCs with a platinum catalyst;
ii) passing heat recovery gas through the second adsorption vessel and the first adsorption vessel in this order to recover heat from the second adsorption material and use the recovered heat to preheat the first adsorption material; step,
iii) Passing the gas to be treated to the second adsorption container to adsorb VOCs contained in the gas to be treated to the second adsorbent, and passing the high temperature regeneration gas to the first adsorption container to cause the second adsorption material to adsorb VOCs contained in the gas to be treated. 1. Desorbing VOCs from the adsorbent and oxidizing the VOCs with the platinum catalyst;
iv) passing the heat recovery gas through the first adsorption vessel and the second adsorption vessel in this order to recover heat from the first adsorption material and using the recovered heat to adsorb the second adsorption material; preheating step,
It is characterized by repeating the above steps i) to iv) in this order.

According to the present invention, it is possible to propose a VOC treatment apparatus and method for cleaning a gas to be treated containing VOC, which achieves energy saving.

FIG. 1 is a diagram showing a schematic configuration of a VOC treatment device according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of the piping configuration of the VOC treatment device. FIG. 3 is a block diagram showing the configuration of a control system of the VOC processing device. FIG. 4 is a timing chart of processing performed in the first adsorption container and the second adsorption container.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a VOC treatment device 1 according to an embodiment of the present invention. The VOC treatment apparatus 1 shown in FIG. 1 includes two VOC adsorption treatment containers, a first adsorption container 11 and a second adsorption container 12. The first adsorption container 11 is filled with a first adsorbent 13a, and the second adsorption container 12 is filled with a second adsorption material 13b. Both the first adsorbent 13a and the second adsorbent 13b are beta-type zeolite.

The VOC treatment device 1 includes a heater 57 and a catalyst 58. The heater 57 heats the regeneration gas used for regenerating the adsorbents 13a, 13b to a desorption temperature at which VOCs are desorbed from the adsorbents 13a, 13b. When the high-temperature regeneration gas comes into contact with the adsorbents 13a, 13b that have adsorbed VOCs, the VOCs adsorbed by the adsorbents 13a, 13b are desorbed from the adsorbents 13a, 13b. The catalyst 58 is a platinum catalyst (oxidation catalyst), and oxidizes the VOCs desorbed from the adsorbents 13a and 13b, and at the same time generates reaction heat.

The VOC processing apparatus 1 is provided with a processed gas inlet 21 that is an inlet for a processed gas, and a processed gas outlet 22 that is an outlet for clean gas from which VOCs have been removed from the processed gas. The VOC treatment apparatus 1 includes a first adsorption line L1 and a second adsorption line L2 through which the gas to be treated flows, a first regeneration loop R1 and a second regeneration loop R2 through which the regeneration gas circulates, and a first regeneration loop through which the heat recovery gas flows. A heat recovery line H1 and a second heat recovery line H2 are provided. The heat recovery gas may be, for example, air.

The first adsorption line L1 is configured to flow the processed gas from the processed gas inlet 21 through the first adsorption container 11 to the processed gas outlet 22. The second adsorption line L2 is configured to flow the processed gas from the processed gas inlet 21 through the second adsorption container 12 to the processed gas outlet 22. The first regeneration loop R1 is configured to circulate the regeneration gas to the first adsorption vessel 11, the heater 57, and the platinum catalyst 58. The second regeneration loop R2 is configured to circulate the regeneration gas to the second adsorption vessel 12, heater 57, and platinum catalyst 58. The first heat recovery line H1 is configured to flow the heat recovery gas to the processing gas outlet 22 through the first adsorption container 11 and the second adsorption container 12 in this order. The second heat recovery line H2 is configured to flow the heat recovery gas through the second adsorption container 12 and the first adsorption container 11 in this order to the processing gas outlet 22.

FIG. 2 is a diagram showing an example of a specific piping configuration of the VOC treatment apparatus 1. As shown in FIG. 2, an introduction path 30 is connected to the gas inlet 21 to be processed. The introduction path 30 is provided with a first blower 41 and a first cooler 42 in this order from the upstream side of the flow of the gas to be processed. In the first cooler 42, the gas to be treated introduced into the VOC treatment apparatus 1 is cooled to a temperature suitable for adsorption by the adsorbents 13a and 13b. The introduction path 30 branches into a first introduction path 31 and a second introduction path 32 at a branch point 43 provided downstream of the first cooler 42 in the flow of the gas to be treated. The first introduction path 31 is connected to the inlet 11a of the first adsorption container 11. The second introduction path 32 is connected to the inlet 12a of the second adsorption container 12.

The first introduction path 31 and the second introduction path 32 are connected by a first connection path 51 on the downstream side of the flow of the gas to be processed from the branch point 43 . A first flow path switching valve 44 is provided at the connection between the first introduction path 31 and the first connection path 51. The first flow path switching valve 44 allows the inlet 11a of the first adsorption container 11 to communicate with the gas inlet 21 to be treated and not communicate with the first connection path 51, and the inlet 11a of the first adsorption container 11 to be connected to the first connection. It is switched to a state in which it is in communication with the passage 51 and out of communication with the gas inlet 21 to be treated. A second flow path switching valve 45 is provided at the connection between the second introduction path 32 and the first connection path 51. The second flow path switching valve 45 allows the inlet 12a of the second adsorption container 12 to be in communication with the gas inlet 21 to be treated and not in communication with the first connection path 51, and the inlet 12a of the second adsorption container 12 to be connected to the first connection. It is switched to a state in which it is in communication with the passage 51 and out of communication with the gas inlet 21 to be treated.

A discharge path 60 is connected to the processing gas outlet 22 . A second cooler 48 is provided in the discharge path 60 . The adsorption reaction of VOC onto the adsorbents 13a and 13b is an exothermic reaction. The clean gas whose temperature has increased thereby is cooled by the second cooler 48. In the discharge passage 60, the first discharge passage 61 and the second discharge passage 62 merge at a confluence point 47 provided upstream of the flow of clean gas from the second cooler 48. The first discharge path 61 is connected to the outlet 11b of the first adsorption container 11. The second discharge path 62 is connected to the outlet 12b of the second adsorption container 12.

The first discharge passage 61 and the second discharge passage 62 are connected by a second connection passage 52 on the upstream side of the flow of clean gas from the confluence point 47 . A third flow path switching valve 46 is provided at the connection between the first discharge path 61 and the second connection path 52. The third flow path switching valve 46 has a state in which the outlet 11b of the first adsorption container 11 is communicated with the processing gas outlet 22 and not in communication with the second connection path 52, and a state in which the outlet 11b of the first adsorption container 11 is in communication with the second connection path. 52 and out of communication with the processing gas outlet 22. A fourth flow path switching valve 49 is provided at the connection between the second discharge path 62 and the second connection path 52. The fourth flow path switching valve 49 is configured such that the outlet 12b of the second adsorption container 12 is in communication with the processing gas outlet 22 and not in communication with the second connection path 52, and the outlet 12b of the second adsorption container 12 is in communication with the second connection path. 52 and out of communication with the processing gas outlet 22.

The midway portion 51a of the first connection path 51 and the midway portion 52a of the second connection path 52 are connected by a regeneration path 53. The regeneration path 53 is provided with a fifth flow path switching valve 55, a second blower 56, a heater 57, and a catalyst 58 in this order from the side connected to the first connection path 51.

An air supply path 70 that supplies air from the outside to an air supply section 71 between the fifth flow path switching valve 55 and the second blower 56 is connected to the regeneration path 53 . A surplus air discharge passage 80 is connected to the regeneration passage 53, which bypasses the second connection passage 52 and the fourth passage switching valve 49 and discharges surplus air directly from the regeneration passage 53 to the second discharge passage 62. ing. The surplus air discharge path 80 is provided with a catalyst 81, a heat exchanger 82, and an on-off valve 83 in this order from the upstream side of the flow of surplus air. The catalyst 81 removes components to be removed, such as VOC, contained in the surplus air discharged from the regeneration path 53 through the surplus air discharge path 80 . The heat exchanger 82 exchanges heat between the air flowing through the air supply path 70 and surplus air, cooling the surplus air and warming the air.

In the VOC treatment apparatus 1 shown in FIG. 2, the first adsorption line L1 is formed by the introduction path 30, the first introduction path 31, the first adsorption container 11, the first discharge path 61, and the discharge path 60. The to-be-treated gas introduced into the first adsorption line L1 from the to-be-treated gas inlet 21 is sent to the downstream side by the first blower 41 while passing through the first cooler 42, the first adsorption container 11, and the second cooler. 48, and is discharged from the processing gas outlet 22 as a clean gas.

The second adsorption line L2 is formed by the introduction path 30, the second introduction path 32, the second adsorption container 12, the second discharge path 62, and the discharge path 60. The to-be-treated gas introduced into the second adsorption line L2 from the to-be-treated gas inlet 21 passes through the first cooler 42, the second adsorption container 12, and the second cooler while being sent downstream by the first blower 41. 48, and is discharged from the processing gas outlet 22 as a clean gas.

The first suction line L1 and the second suction line L2 share the introduction path 30 and the discharge path 60. Thereby, each device of the first blower 41, the first cooler 42, and the second cooler 48 can be used in common without being provided in each of the first suction line L1 and the second suction line L2. .

Furthermore, in the VOC treatment device 1 shown in FIG. and a portion of the first connection path 51. In the first regeneration loop R1, the regeneration gas (air) introduced through the air supply path 70 is heated by the heater 57 and becomes hot gas, which is circulated through the first regeneration loop R1 by the action of the second blower 56. The second blower 56 blows air so that the regeneration gas enters from the outlet 11b of the first adsorption container 11 and exits from the inlet 11a, that is, flows in the opposite direction to the gas to be treated. While passing through the first adsorption container 11, the regeneration gas comes into contact with the first adsorbent 13a and desorbs VOCs. The desorbed VOCs flow through the first regeneration loop R1 together with the regeneration gas and pass through the catalyst 58. In the catalyst 58, VOCs accompanying the regeneration gas are oxidized.

The second regeneration loop R2 includes the regeneration path 53, a portion of the second connection path 52, a portion of the second discharge path 62, the first adsorption container 11, a portion of the second introduction path 32, and a portion of the first connection path 51. It is formed. In the second regeneration loop R2, the regeneration gas (air) introduced through the air supply path 70 is heated by the heater 57 and becomes hot gas, which is circulated through the second regeneration loop R2 by the action of the second blower 56. The second blower 56 blows air so that the regeneration gas enters the second adsorption container 12 from the outlet 12b and exits from the inlet 12a, that is, flows in the opposite direction to the gas to be treated. While passing through the second adsorption container 12, the regeneration gas comes into contact with the second adsorbent 13b and desorbs VOCs. The desorbed VOCs flow through the second regeneration loop R2 together with the regeneration gas and pass through the catalyst 58. In the catalyst 58, VOCs accompanying the regeneration gas are oxidized.

The first reproduction loop R1 and the second reproduction loop R2 share the reproduction path 53. As a result, each device such as the fifth flow path switching valve 55, the second blower 56, the heater 57, and the catalyst 58 can be shared between the first regeneration loop R1 and the second regeneration loop R2 without being provided in each loop. be able to.

Furthermore, in the VOC treatment apparatus 1 shown in FIG. It is formed by the container 11, a part of the first introduction path 31, the first connection path 51, a part of the second introduction path 32, the second adsorption container 12, the second discharge path 62, and the discharge path 60. The heat recovery gas introduced through the air supply path 70 is discharged from the processing gas outlet 22 through the first heat recovery line H1 by the action of the second blower 56.

The first heat recovery line H1 is formed using the first regeneration loop R1 and the second adsorption line L2. As shown in FIG. 1, the first regeneration loop R1 is configured to be shut off by a shutoff section 90 provided downstream of the first adsorption vessel 11 in the flow of regeneration gas. Then, in the first regeneration loop R1 cut off by the cutoff part 90, a first connection part 91 provided on the downstream side of the flow of regeneration gas than the first adsorption container 11 is connected to a second adsorption container of the second adsorption line L2. The first heat recovery line H1 using the first regeneration loop R1 and the second adsorption line L2 is connected to the second connection part 92 provided upstream of the flow of the gas to be treated than the first heat recovery line H1. It is formed. As shown in FIG. 2, the blocking section 90 is configured with the fifth flow path switching valve 55, the first connection section 91 is configured with the first flow path switching valve 44, and the second connection section 92 is configured with the second flow path switching valve 55. The first connection path 51 may be configured by the valve 45, and a flow path connecting the first connection portion 91 and the second connection portion 92.

In the VOC treatment apparatus 1 shown in FIG. , a part of the second introduction path 32 , the first connection path 51 , a part of the first introduction path 31 , the first adsorption container 11 , the first discharge path 61 , and the discharge path 60 . The heat recovery gas introduced through the air supply path 70 is discharged from the processing gas outlet 22 through the second heat recovery line H2 by the action of the second blower 56.

The second heat recovery line H2 is formed using the second regeneration loop R2 and the first adsorption line L1. As shown in FIG. 1, the second regeneration loop R2 is configured to be shut off by a shutoff section 90 provided downstream of the second adsorption vessel 12 in the flow of regeneration gas. Then, in the second regeneration loop R2 cut off by the cutoff part 90, a third connection part 93 provided on the downstream side of the flow of regeneration gas than the second adsorption container 12 is connected to the first adsorption container of the first adsorption line L1. 11 is connected to the fourth connection part 94 provided upstream of the flow of the gas to be treated, the second heat recovery line H2 using the second regeneration loop R2 and the first adsorption line L1 is connected. It is formed. As shown in FIG. 2, the third connecting portion 93 is configured with the second flow path switching valve 45, the fourth connecting portion 94 is configured with the first flow path switching valve 44, and the second connecting portion 92 and the third connecting portion are configured with the second flow path switching valve 45. The flow path connecting the portion 93 may be configured as the first connection path 51.

FIG. 3 is a block diagram showing the configuration of the control system of the VOC processing device 1. As shown in FIG. As shown in FIG. 3, the VOC treatment apparatus 1 shown in FIG. The operations of the five-channel switching valve 55 and the on-off valve 83 are controlled by the control device 9. Further, the operation of the first blower 41 and the second blower 56 included in the VOC treatment device 1 is controlled by the control device 9. Furthermore, the operations of the first cooler 42 and the second cooler 48 included in the VOC treatment device 1 are controlled by the control device 9.

The control device 9 includes a processor, memories such as ROM and RAM, and an I/O section (all not shown). Drive units for valves 44 to 46, 49, 55, and 83, blowers 41, 56, coolers 42, 48, and a heater 57 are connected to the control device 9 via an I/O unit. The control device 9 may include a single processor that performs centralized control, or may include a plurality of processors that perform distributed control. The memory and storage means store basic programs, application programs, etc. that are executed by the processor. The application program is configured to cause the processor to process each functional unit. The function of the control device 9 is realized by the processor reading and executing the program.

The control device 9 operates the adsorption flow path switching device D1 to selectively switch the flow path (adsorption flow path) of the gas to be treated between the first adsorption line L1 and the second adsorption line L2. In the example shown in FIG. 2, the first channel switching valve 44, the second channel switching valve 45, the third channel switching valve 46, and the fourth channel switching valve 49 function as the adsorption channel switching device D1.

The control device 9 operates the regeneration flow path switching device D2 to selectively switch the regeneration gas flow path (regeneration flow path) between the first regeneration loop R1 and the second regeneration loop R2. In the example shown in FIG. 2, the fifth channel switching valve 55, the first channel switching valve 44, the second channel switching valve 45, the third channel switching valve 46, and the fourth channel switching valve 49 It functions as a path switching device D2.

The control device 9 uses a heat recovery channel switching device D3 to selectively switch the heat recovery gas flow channel (heat recovery channel) between the first heat recovery line H1 and the second heat recovery line H2. make it work. In the example shown in FIG. 2, the fifth channel switching valve 55, the first channel switching valve 44, the second channel switching valve 45, the third channel switching valve 46, and the fourth channel switching valve 49 are heat recovery It functions as a flow path switching device D3.

[Operation method of VOC treatment device 1]
Here, a method of operating the VOC treatment device 1 having the above configuration will be explained. FIG. 4 is a timing chart of the processing performed in the first adsorption container 11 and the second adsorption container 12.

As shown in FIG. 4, in the first step, an adsorption process is performed in which VOCs contained in the gas to be treated are adsorbed to the first adsorbent 13a in the first adsorption container 11, and a second adsorption process is performed in the second adsorption container 12. A regeneration process is performed to desorb VOC from the material 13b. In the first step, the first adsorption line L1 is effective as an adsorption channel through which the gas to be treated flows, and the second adsorption line L2 is ineffective, and the second regeneration loop R2 is effective as a regeneration channel through which the regeneration gas flows. Yes, and the first regeneration loop R1 is invalid, and both the first heat recovery line H1 and the second heat recovery line H2 are invalid. The VOC contained in the gas flowing through the first adsorption line L1 is adsorbed and removed by the first adsorbent 13a while passing through the first adsorption container 11, and the gas is discharged from the processing gas outlet 22 as a clean gas. The regeneration gas circulating in the second regeneration loop R2 is heated by the heater 57, and desorbs the VOCs adsorbed on the second adsorbent 13b while passing through the second adsorption container 12, and the desorbed VOCs are transferred to the catalyst 58. carry it to VOCs are oxidized by a catalyst 58.

In the second step following the first step, the flow of the gas to be treated is temporarily stopped, the heat held by the second adsorbent 13b of the second adsorption container 12 is recovered, and the heat is transferred to the first adsorption material 13b of the first adsorption container 11. It is applied to the adsorbent 13a. Thereby, the second adsorbent 13b is cooled and the first adsorbent 13a is preheated. In the second step, the first adsorption line L1, the second adsorption line L2, the first regeneration loop R1, the second regeneration loop R2, and the first heat recovery line H1 are all invalid, and only the second heat recovery line H2 is valid. The heat recovery gas flowing through the second heat recovery line H2 recovers the heat generated during the regeneration of the second adsorbent 13b while flowing through the second adsorption container 12, and then recovers the heat generated during the regeneration of the second adsorption material 13b while flowing through the first adsorption container 11. The adsorbent 13a is heated. Note that while the heat recovery gas is flowing through the second heat recovery line H2, the heater 57 does not operate, and the catalyst 58 is not activated because the temperature of the heat recovery gas is insufficient.

In the third step following the second step, an adsorption process is performed in which VOCs contained in the gas to be treated are adsorbed to the second adsorbent 13b in the second adsorption container 12, and in the first adsorption container 11, VOCs are removed from the first adsorbent 13a. A regeneration process is performed to desorb the VOCs. In the third step, the second adsorption line L2 is effective as the adsorption channel through which the gas to be treated flows, and the first adsorption line L1 is ineffective, and the first regeneration loop R1 is effective as the regeneration channel through which the regeneration gas flows. Yes, and the second regeneration loop R2 is invalid, and both the first heat recovery line H1 and the second heat recovery line H2 are invalid. The VOC contained in the gas to be treated flowing through the second adsorption line L2 is adsorbed and removed by the second adsorbent 13b while passing through the second adsorption container 12, and the gas is discharged from the treatment gas outlet 22 as a clean gas. The regeneration gas circulating in the first regeneration loop R1 is heated by the heater 57, and desorbs the VOCs adsorbed on the first adsorbent 13a while passing through the first adsorption container 11, and the desorbed VOCs are transferred to the catalyst 58. carry it to VOCs are oxidized by a catalyst 58.

At the start of the third step, the second adsorbent 13b of the second adsorption container 12 has been cooled and the first adsorbent 13a of the first adsorption container 11 has been preheated. Compared to the case where it is omitted, stable processing can be started quickly.

In the fourth step following the third step, the flow of the gas to be treated is temporarily stopped, the heat held by the first adsorbent 13a of the first adsorption container 11 is recovered, and the heat is transferred to the second adsorption material 13a of the second adsorption container 12. It is applied to the adsorbent 13b. As a result, the first adsorbent 13a is cooled and the second adsorbent 13b is preheated. In the second step, all of the first adsorption line L1, second adsorption line L2, first regeneration loop R1, second regeneration loop R2, and second heat recovery line H2 are invalid, and only the first heat recovery line H1 is valid. The heat recovery gas flowing through the first heat recovery line H1 recovers the heat generated during regeneration of the first adsorbent 13a while flowing through the first adsorption container 11, and then recovers the heat generated during the regeneration of the first adsorbent 13a while flowing through the second adsorption container 12. The adsorbent 13b is heated. While the heat recovery gas is flowing through the first heat recovery line H1, the heater 57 does not operate, and the catalyst 58 is not activated because the temperature of the heat recovery gas is insufficient.

When the fourth step is finished, the process returns to the first step. At the start of the first step following the fourth step, the first adsorbent 13a of the first adsorption container 11 has been cooled and the second adsorbent 13b of the second adsorption container 12 has been preheated. , compared to the case where the fourth step is omitted, stable processing can be started quickly.

As explained above, the VOC treatment device 1 of this embodiment is
A first adsorption container 11 and a second adsorption container 12 filled with adsorbents 13a and 13b made of beta zeolite that adsorb VOCs,
a first adsorption line L1 that allows the gas to be treated containing VOC to flow from the gas inlet 21 to the gas outlet 22 through the first adsorption container 11;
a second adsorption line L2 that flows the processed gas inlet 21 from the processed gas inlet 21 through the second adsorption container 12 to the processed gas outlet 22;
a heater 57 that heats the regeneration gas to the desorption temperature of the VOCs adsorbed on the adsorbents 13a and 13b;
a platinum catalyst 58 that oxidizes VOCs desorbed from the adsorbents 13a and 13b and accompanying the regeneration gas;
a first regeneration loop R1 that circulates the regeneration gas to the first adsorption container 11, the heater 57, and the platinum catalyst 58;
a second regeneration loop R2 that circulates the regeneration gas to the second adsorption container 12, the heater 57, and the platinum catalyst 58;
a first heat recovery line H1 that causes the heat recovery gas to pass through the first adsorption container 11 and the second adsorption container 12 in order and flow to the processing gas outlet 22;
a second heat recovery line H2 that causes the heat recovery gas to pass through the second adsorption container 12 and the first adsorption container 11 in order and flow to the processing gas outlet 22;
an adsorption flow path switching device D1 that selectively switches the flow path of the gas to be treated between a first adsorption line L1 and a second adsorption line L2;
a regeneration flow path switching device D2 that selectively switches the regeneration gas flow path between a first regeneration loop R1 and a second regeneration loop R2;
a heat recovery flow path switching device D3 that selectively switches the heat recovery gas flow path between the first heat recovery line H1 and the second heat recovery line H2;
It includes a control device 9 that controls the operations of the adsorption channel switching device D1, the regeneration channel switching device D2, and the heat recovery channel switching device D3.
Here, the control device 9 controls the regeneration gas to circulate through the second regeneration loop R2 when the gas to be treated is flowing to the first adsorption line L1, and the regeneration gas to be circulated to the second adsorption line L2 when the gas to be treated is flowing to the second adsorption line L2. The regeneration gas circulates through the first regeneration loop R1, and while the flow of the gas to be treated is temporarily stopped and the flow path of the gas to be treated is switched from the first adsorption line L1 to the second adsorption line L2, the heat recovery gas is converted into a second heat source. The heat recovery gas flows through the first heat recovery line H1 while the flow of the gas to be treated is temporarily stopped and the flow path of the gas to be treated is switched from the second adsorption line L2 to the first adsorption line L1. It is configured to control the operations of the adsorption channel switching device D1, the regeneration channel switching device D2, and the heat recovery channel switching device D3.
In the VOC treatment apparatus 1, the first adsorption line L1, the second adsorption line L2, the first regeneration loop R1, the second regeneration loop R2, the first heat recovery line H1, and the second heat recovery line H2 are flow paths. It does not matter if they partially overlap.

Further, in the VOC treatment method according to one aspect of the present invention, a first adsorbent 13a filled in the first adsorption container 11 and a second adsorbent filled in the second adsorption container 12 are both made of beta-type zeolite. 13b to remove VOCs from a gas to be treated, the method comprises:
i) The gas to be treated is passed through the first adsorption container 11 to cause the first adsorbent 13a to adsorb VOCs contained in the gas to be treated, and the high temperature regeneration gas is passed through the second adsorption container 12 to the second adsorbent 13b. a step of desorbing VOCs from and oxidizing the VOCs with a platinum catalyst 58;
ii) Passing the heat recovery gas to the second adsorption container 12 and the first adsorption container 11 in this order to recover heat from the second adsorption material 13b, and use the recovered heat to preheat the first adsorption material 13a. step,
iii) Passing the gas to be treated to the second adsorption container 12 to adsorb VOCs contained in the gas to be treated to the second adsorbent 13b, and passing high temperature regeneration gas to the first adsorption container 11 to adsorb the VOCs contained in the gas to be treated to the second adsorbent 13b. a step of desorbing VOCs from and oxidizing the VOCs with a platinum catalyst 58;
iv) Heat recovery gas is passed through the first adsorption container 11 and the second adsorption container 12 in this order to recover heat from the first adsorption material 13a, and use the recovered heat to preheat the second adsorption material 13b. step,
It is characterized by repeating the above steps i) to iv) in this order.

According to the VOC treatment apparatus 1 and the VOC treatment method configured as described above, the heat recovery gas is By flowing through the second adsorption container 12 and the first adsorption container 11 in this order, the second adsorption material 13b of the second adsorption container 12 is cooled by recovering the heat generated by regeneration, and The first adsorbent 13a is preheated using the recovered heat. Similarly, while the processing container that performs the process of adsorbing and removing VOCs from the gas to be processed is switched from the second adsorption container 12 to the first adsorption container 11, the heat recovery gas flows into the first adsorption container 11 and the second adsorption container 12. By flowing in this order, the first adsorbent 13a of the first adsorption container 11 is cooled by recovering the heat generated during regeneration, and the second adsorbent 13b of the second adsorption container 12 is preheated with the recovered heat. be done. The thus cooled adsorbents 13a and 13b are subjected to a process of adsorbing and removing VOCs, and the preheated adsorbents 13a and 13b are subjected to a process of desorbing and regenerating VOCs. Therefore, compared to the case where the adsorbents 13a and 13b are cooled and preheated using energy given from the outside, energy saving can be achieved.

Furthermore, in the VOC treatment apparatus 1 and VOC treatment method, since the VOCs contained in the gas to be treated are once condensed on the adsorbents 13a and 13b and then treated with the catalyst 58, even if the VOCs contained in the gas to be treated are low. Even if the concentration is low, VOCs can be efficiently removed.

In particular, in the above VOC treatment method, since the adsorption of VOC by the adsorbents 13a and 13b and the desorption of VOC from the adsorbents 13a and 13b are repeated, it is possible to maintain good removal performance for a long time with minimal maintenance. I can do it.

Further, in the VOC treatment apparatus 1 according to the present embodiment, the first regeneration loop R1 is configured to be able to be shut off at the shutoff section 90 on the downstream side of the flow of regeneration gas from the first adsorption vessel 11. The first connection part 91 provided downstream of the flow of regeneration gas from the first adsorption vessel 11 in the interrupted first regeneration loop R1 and the gas to be treated from the second adsorption vessel 12 of the second adsorption line L2. A first heat recovery line H1 using the first regeneration loop R1 and the second adsorption line L2 is formed by connecting the second connection part 92 provided on the upstream side of the flow.

According to the VOC treatment device 1 having the above configuration, the first heat recovery line H1 is formed using the first regeneration loop R1 and the second adsorption line L2, thereby reducing the piping space and the length of the piping. This is advantageous in cost reduction. Furthermore, since the heat of the piping of the first regeneration loop R1 heated by the circulation of the regeneration gas can also be used to preheat the second adsorption vessel 12, further energy saving can be realized.

Similarly, in the VOC treatment apparatus 1 according to the present embodiment, the second regeneration loop R2 is configured to be able to be shut off by the shutoff section 90 on the downstream side of the flow of regeneration gas from the second adsorption vessel 12. In the second regeneration loop R2, which is cut off by A second heat recovery line H2 using the second regeneration loop R2 and the first adsorption line L1 is formed by being connected to the fourth connection part 94 provided on the upstream side of the gas flow.

According to the VOC treatment device 1 having the above configuration, the second heat recovery line H2 is formed using the second regeneration loop R2 and the first adsorption line L1, thereby reducing the piping space and the length of the piping. This is advantageous in cost reduction. Furthermore, since the heat of the pipes of the second regeneration loop R2 heated by the circulation of the regeneration gas can also be used for preheating the first adsorption vessel 11, further energy saving can be realized.

Flow paths required for adsorption of VOC by adsorbents 13a, 13b and regeneration of adsorbents 13a, 13b (first adsorption line L1, second adsorption line L2, first regeneration loop R1, and second regeneration loop R2) can be used to form the first heat recovery line H1 and the second heat recovery line H2.

Although the preferred embodiments of the present invention have been described above, the present invention may include modifications to the specific structure and/or functional details of the above embodiments without departing from the spirit of the present invention. . The above configuration can be modified as follows, for example.

For example, in the VOC treatment apparatus 1 according to the above embodiment, the first heat recovery line H1 and the second heat recovery line H2 are connected to the first adsorption line L1, the second adsorption line L2, the first regeneration loop R1, and the second regeneration loop. It is formed by using the flow path of loop R2 and switching the flow path with a valve. By forming the first heat recovery line H1 and the second heat recovery line H2 using the flow paths for adsorption processing and regeneration processing in this way, the piping space can be reduced and the piping length can be suppressed. It is advantageous in cost reduction. However, at least one of the first heat recovery line H1 and the second heat recovery line H2 uses the flow paths of the first adsorption line L1, the second adsorption line L2, the first regeneration loop R1, and the second regeneration loop R2. It may be formed without any.

1: VOC treatment device 9: Control device 11: First adsorption container 12: Second adsorption container 13a, 13b: Adsorbent 21: Processed gas inlet 22: Processed gas outlet 41, 56: Blower 42, 48: Cooler 57 : Heater 58 : Platinum catalyst D1 : Adsorption channel switching device D2 : Regeneration channel switching device D3 : Heat recovery channel switching device H1 : First heat recovery line H2 : Second heat recovery line L1 : First adsorption line L2 :2nd adsorption line R1 :1st regeneration loop R2 :2nd regeneration loop

Claims (4)

A first adsorption container and a second adsorption container filled with an adsorbent made of beta zeolite that adsorbs VOCs;
a first adsorption line that allows a gas to be treated containing VOC to flow from an inlet of the gas to be treated through the first adsorption container to an outlet of the treated gas;
a second adsorption line that allows the to-be-treated gas to flow from the to-be-treated gas inlet through the second adsorption container to the to-be-treated gas outlet;
a heater that heats the regeneration gas to the desorption temperature of the VOCs adsorbed on the adsorbent;
a platinum catalyst that oxidizes VOCs desorbed from the adsorbent and entrained in the regeneration gas;
a first regeneration loop that circulates the regeneration gas to the first adsorption vessel, the heater, and the platinum catalyst;
a second regeneration loop that circulates the regeneration gas to the second adsorption vessel, the heater, and the platinum catalyst;
a first heat recovery line that causes the heat recovery gas to flow through the first adsorption container and the second adsorption container in order to the treated gas outlet;
a second heat recovery line that causes the heat recovery gas to flow through the second adsorption container and the first adsorption container in order to the processing gas outlet;
an adsorption flow path switching device that selectively switches the flow path of the gas to be treated between the first adsorption line and the second adsorption line;
a regeneration flow path switching device that selectively switches the regeneration gas flow path between the first regeneration loop and the second regeneration loop;
a heat recovery flow path switching device that selectively switches the flow path of the heat recovery gas between the first heat recovery line and the second heat recovery line;
When the gas to be treated is flowing through the first adsorption line, the regeneration gas is circulated through the second regeneration loop, and when the gas to be treated is flowing through the second adsorption line, the regeneration gas is circulating through the second regeneration loop. The heat recovery gas circulates through the first regeneration loop, and while the flow of the gas to be treated is temporarily stopped and the flow path of the gas to be treated is switched from the first adsorption line to the second adsorption line, the heat recovery gas The heat recovery gas passes through the first heat recovery line while the flow of the process gas is temporarily stopped and the flow path of the process gas is switched from the second adsorption line to the first adsorption line. a control device that controls the operation of the adsorption channel switching device, the regeneration channel switching device, and the heat recovery channel switching device so that the heat recovery channel switching device flows;
VOC treatment equipment. The first regeneration loop is configured to be shut off at a cutoff section downstream of the flow of the regeneration gas from the first adsorption vessel, and the first regeneration loop is cut off at the cutoff section, and the first adsorption A first connection part provided on the downstream side of the flow of the regeneration gas with respect to the container, and a second connection provided on the upstream side of the flow of the to-be-treated gas with respect to the second adsorption container of the second adsorption line. The first heat recovery line utilizing the first regeneration loop and the second adsorption line is formed by connecting the first heat recovery loop and the second adsorption line.
The VOC treatment device according to claim 1. The second regeneration loop is configured to be shut off at a cutoff section downstream of the flow of the regeneration gas from the second adsorption vessel, and the second regeneration loop is cut off at the cutoff section. a third connection provided on the downstream side of the flow of the regeneration gas with respect to the container; and a fourth connection provided on the upstream side of the flow of the to-be-treated gas with respect to the first adsorption container of the first adsorption line. The second heat recovery line utilizing the second regeneration loop and the first adsorption line is formed by connecting the second regeneration loop and the first adsorption line.
The VOC treatment device according to claim 1 or 2. A VOC treatment method for removing VOCs from a gas to be treated using a first adsorbent filled in a first adsorption container and a second adsorption material filled in a second adsorption container, both of which are made of beta-type zeolite. hand,
i) Passing the gas to be treated through the first adsorption container to cause the first adsorbent to adsorb VOCs contained in the gas to be treated, and passing high-temperature regeneration gas through the second adsorption container to the second adsorption material. a step of desorbing VOCs from the adsorbent and oxidizing the VOCs with a platinum catalyst;
ii) passing heat recovery gas through the second adsorption vessel and the first adsorption vessel in this order to recover heat from the second adsorption material and use the recovered heat to preheat the first adsorption material; step,
iii) Passing the gas to be treated to the second adsorption container to adsorb VOCs contained in the gas to be treated to the second adsorbent, and passing the high temperature regeneration gas to the first adsorption container to cause the second adsorption material to adsorb VOCs contained in the gas to be treated. 1. Desorbing VOCs from the adsorbent and oxidizing the VOCs with the platinum catalyst;
iv) passing the heat recovery gas through the first adsorption vessel and the second adsorption vessel in this order to recover heat from the first adsorption material and using the recovered heat to adsorb the second adsorption material; preheating step,
Repeat steps i) to iv) above in this order,
VOC treatment method.

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