JP7181697B2 - VOC recovery device and VOC recovery method - Google Patents

Description

The present invention relates to a VOC recovery device and a VOC recovery method.

For example, in the printing and production of adhesive tapes, there is a drying process in which a solvent is applied and dried. When the solvent is dried in the drying process, various volatile organic compounds (hereinafter referred to as VOC) volatilize from the solvent. Volatilized VOCs are burned or recovered and reused. Also, when recovering VOCs, for example, an adsorbent disclosed in Patent Document 1 is used. Further, Patent Document 2 discloses a technique for adsorbing a substance with a high boiling point to activated carbon.

JP 2017-064618 A JP 2016-194504 A

When VOCs are adsorbed and recovered by a recovery rotor, substances adsorbed by the recovery rotor include:
In addition to the VOCs to be collected, substances (hereinafter referred to as impurities) such as ink components used in printing and adhesives used in adhesive tapes are also included.

When impurities adhere to the recovery rotor, the recovery function of the recovery rotor deteriorates. Therefore, it is conceivable to replace the recovery rotor at a predetermined frequency as a countermeasure against the deterioration of the recovery function. However, if the recovery rotor is frequently replaced, maintenance costs may increase.

Therefore, it is conceivable to heat the recovery rotor at a predetermined timing to desorb and remove the impurities adhering to the rotor, thereby regenerating the function of the recovery rotor. If this is the case, there is no need to replace the recovery rotor. However, the impurities may include, for example, a substance with a high boiling point as disclosed in Patent Document 2, and it may be necessary to set the heating temperature to a high temperature. That is, even this countermeasure requires energy costs, and there is a risk that maintenance costs will increase. Therefore, as disclosed in Patent Document 2, it is conceivable to provide activated carbon separately from the recovery rotor to adsorb and recover the impurities. However, in Patent Document 2, since it is assumed that the activated carbon is replaced, maintenance costs may increase if the activated carbon is frequently replaced. In order to reduce maintenance costs, it is conceivable to regenerate the activated carbon by heating the activated carbon to desorb the adsorbed impurities. That is, even if activated carbon is provided separately from the recovery rotor to adsorb and recover impurities, it is difficult to reduce maintenance costs.

Therefore, it is an object of the present application to provide a technique capable of maintaining the recovery function while suppressing maintenance costs even when impurities are contained in the VOCs to be recovered.

In order to solve the above problems, the present invention adsorbs and removes impurities contained in VOCs before adsorbing and recovering VOCs.

Specifically, the present invention provides an adsorption recovery unit that adsorbs and recovers VOCs to be recovered, and an adsorbent used for pretreatment of adsorption recovery in the adsorption recovery unit, wherein the temperature is higher than the regeneration temperature of the adsorption recovery unit. and an impurity adsorbent that is temperature tolerant and adsorbs impurities mixed in the VOCs to be recovered.

Here, the term "impurities" refers to substances other than VOCs to be recovered, which are not desorbed from the adsorption/recovery section at the regeneration temperature of the adsorption/recovery section when the adsorption/recovery section is regenerated. In addition, the impurity adsorbent has heat resistance at temperatures of about several hundred degrees.

With such a VOC recovery device, adsorption of impurities to the adsorption recovery section is suppressed. Therefore, the recovery function of the adsorption recovery unit continues. Therefore, the frequency of replacement of the adsorption recovery unit is reduced, and maintenance costs are saved.

Further, when the impurity adsorbent is heated to a temperature higher than the regeneration temperature of the adsorption recovery unit and at which impurities are desorbed from the impurity adsorbent, the impurities can be desorbed and the impurity adsorbent can be regenerated. Therefore, the function of adsorbing impurities of the impurity adsorbent continues. That is, the suppression of adsorption of impurities in the adsorption/recovery section continues, and the recovery function of the adsorption/recovery section also continues. In addition, since the impurity adsorbent is regenerated without replacement, maintenance costs are reduced.

In addition, in the case of a VOC recovery device that does not have an impurity adsorbent, impurities are adsorbed in the adsorption recovery section. In order to desorb impurities from the adsorption/recovery part, it is necessary to heat the adsorption/recovery part to a temperature higher than the normal regeneration temperature. When the adsorption/recovery unit is heated to a temperature higher than the normal regeneration temperature, the VOC itself adsorbed in the adsorption/recovery unit is also chemically decomposed, which may affect VOC recovery. However, with this VOC recovery device, there is no need to heat the adsorption recovery unit to a temperature higher than the normal regeneration temperature, so there is no risk that the VOCs themselves will be chemically decomposed, and there is a risk that the recovery of the VOCs will be affected. Nor.

Also, the VOC recovery apparatus may further include a heating unit that heats the impurity adsorbent.

In such a VOC recovery apparatus, when the impurity adsorbent is heated to a temperature higher than the regeneration temperature of the adsorption recovery unit and at a temperature at which impurities are desorbed from the impurity adsorbent, the impurities are desorbed and the impurities are adsorbed. The material can be recycled. Therefore, the function of adsorbing impurities of the impurity adsorbent continues. That is, the suppression of adsorption of impurities in the adsorption/recovery section continues, and the recovery function of the adsorption/recovery section also continues. In addition, since the impurity adsorbent is regenerated without replacement, maintenance costs are reduced.

Also, the heating unit may heat the impurity adsorbent to 300 degrees or higher.

With such a VOC recovery apparatus, depending on the type of impurity, the bonds between the molecules of the impurity are likely to break. That is, the desorption of impurities from the impurity adsorbent is promoted, and the degree of regeneration of the impurity adsorbent is enhanced.

Also, the impurity adsorbent may have adsorption performance to adsorb more impurities than VOCs.

In such a VOC recovery apparatus, the impurity adsorbent adsorbs more impurities than VOCs. In other words, the adsorption of VOCs in the pretreatment is suppressed, and the decrease in the amount of VOCs recovered in the adsorption recovery section is suppressed.

Also, the VOC includes an adsorption recovery unit that adsorbs and recovers the VOC to be recovered, and a Wakkanai layer diatom shale that is used for pretreatment of the adsorption recovery in the adsorption recovery unit and adsorbs impurities mixed in the VOC to be recovered. It may be a recovery device.

With such a VOC recovery device, adsorption of impurities to the adsorption recovery section is suppressed. Therefore, the recovery function of the adsorption recovery unit continues. In addition, the frequency of replacing the adsorption recovery unit is reduced, and maintenance costs are saved.

Further, with such a VOC recovery device, when the Wakkanai layer diatom shale is heated to a temperature higher than the regeneration temperature of the adsorption recovery unit and at a temperature at which impurities are desorbed from the Wakkanai layer diatom shale, impurities are desorbed. Wakkanai Formation diatom shale can be regenerated. Therefore, the function of adsorbing impurities in the Wakkanai diatom shale continues. That is, the suppression of adsorption of impurities in the adsorption/recovery section continues, and the recovery function of the adsorption/recovery section also continues. In addition, since the Wakkanai Formation diatom shale is regenerated without replacement, maintenance costs are reduced.

In addition, the Wakkanai Formation diatom shale has the property of adsorbing more impurities than VOCs. In other words, the adsorption of VOCs in the pretreatment is suppressed, and the decrease in the amount of VOCs recovered in the adsorption recovery section is suppressed. In addition, since the Wakkanai Formation diatom shale is inexpensive, it is possible to reduce the cost of equipment.

In addition, in the case of a VOC recovery apparatus that does not include the Wakkanai Formation diatom shale, impurities are adsorbed in the adsorption recovery section. In order to desorb impurities from the adsorption/recovery part, it is necessary to heat the adsorption/recovery part to a temperature higher than the normal regeneration temperature. When the adsorption/recovery unit is heated to a temperature higher than the normal regeneration temperature, the VOC itself adsorbed in the adsorption/recovery unit is also chemically decomposed, which may affect VOC recovery. However, with this VOC recovery device, there is no need to heat the adsorption recovery unit to a temperature higher than the normal regeneration temperature, so there is no risk that the VOCs themselves will be chemically decomposed, and there is a risk that the recovery of the VOCs will be affected. Nor.

Moreover, a humidity controller may be further provided for adjusting the relative humidity of the gas containing the VOCs to be recovered to less than 60%. With the VOC recovery apparatus as described above, adsorption of water molecules to the impurity adsorbent or Wakkanai diatom shale is suppressed. In other words, the adsorption of impurities is suppressed from being affected.

The present invention can also be viewed from a method aspect. That is, for example, the adsorption recovery step in which the adsorption recovery unit adsorbs and recovers the VOCs to be recovered, and the adsorbent used for the pretreatment of the adsorption recovery in the adsorption recovery step, and the temperature is higher than the regeneration temperature of the adsorption recovery unit. and an impurity adsorption step in which an impurity adsorbent having resistance to temperature adsorbs impurities mixed in the VOC to be recovered.

The VOC recovery apparatus and the VOC recovery method described above can maintain the recovery function while suppressing maintenance costs even when impurities are contained in the VOC to be recovered.

FIG. 1 shows an example of the outline of the VOC recovery device according to the first embodiment. FIG. 2 shows an example of a comparison of the amount of VOCs adsorbed by the recovery rotor when the pretreatment adsorption section is provided and when the pretreatment adsorption section is not provided. FIG. 3 shows an example of a comparison of characteristics between the Wakkanai Formation diatom shale and other candidate impurity adsorbents. FIG. 4 shows an example of comparison between the amount of VOCs adsorbed by the impurity adsorbent and the amount of impurities adsorbed. FIG. 5 shows an example of a flow chart showing the operation of the VOC recovery device. FIG. 6 shows an example of the VOC adsorption amount in the recovery rotor when impurities are adsorbed and removed by the pretreatment adsorption section. FIG. 7 shows an example of the outline of the VOC recovery device according to the second embodiment. FIG. 8 shows an example of the operation of the VOC recovery device. FIG. 9 shows an example of the operation of the VOC recovery device. FIG. 10 shows an example of the VOC adsorption amount in the recovery rotor when the pretreatment adsorption section is thermally regenerated. FIG. 11 shows an example of a comparison of water adsorption amounts between Wakkanai diatomaceous shale and other diatomaceous earths.

Embodiments of the present invention will be described below. The embodiments shown below are examples of embodiments of the present invention, and the technical scope of the present invention is not limited to the following aspects.

<Device configuration>
FIG. 1 shows an example of an outline of a VOC recovery device 100 according to the first embodiment. The VOC recovery apparatus 100 recovers VOCs generated from a drying furnace 1 that performs a drying step of applying an organic solvent and drying it, for example, when printing or manufacturing an adhesive tape. Here, VOC is a substance such as toluene or ethyl acetate, and refers to a volatile organic compound volatilized from an organic solvent when the organic solvent is dried.

A VOC recovery device 100 includes a recovery rotor 2 that recovers VOCs volatilized in a drying furnace 1 . Here, the recovery rotor 2 is an example of the "adsorption recovery section" of the present invention. The VOC recovery device 100 also includes a pipe connecting the drying furnace 1 and the recovery rotor 2 . The pipe forms a circulation path including the drying furnace 1 and the recovery rotor 2 .

The VOC recovery apparatus 100 also includes a pretreatment adsorption section 3 that adsorbs impurities contained in VOCs, between the drying furnace 1 and the recovery rotor 2 and upstream of the recovery rotor 2 . Impurities are substances such as 2-ethylhexyl acrylate and butyl acrylate, for example, and are substances mixed in the organic solvent in the drying furnace 1 . The pretreatment adsorption part 3 contains Wakkanai diatomaceous shale that adsorbs impurities such as 2-ethylhexyl acrylate and butyl acrylate. Here, the Wakkanai Formation diatom shale is an example of the "impurity adsorbent" of the present invention.

The recovery rotor 2 has an adsorption zone 4 that adsorbs VOCs on the rotor surface. The recovery rotor 2 also includes a desorption zone 5 for desorbing VOCs adhering to the rotor surface. The VOC recovery apparatus 100 also includes a heater 6 upstream of the desorption zone 5 that sends heated gas to the desorption zone 5 to regenerate the rotor surface. The heat source of the heater 6 may be residual heat from a production facility that discharges VOCs, or heat from an electric heater.

The VOC recovery system 100 also includes a cooler 7 having a drain pan downstream of the desorption zone 5 . The VOC recovery device 100 also includes a recovery container 8 that is connected to the drain pan and temporarily stores the condensed liquid. The recovery rotor 2 also includes a cooling zone 9 into which the cooling gas cooled by the cooler 7 flows to cool the rotor surface.

Here the heater 6 is located downstream of the cooling zone 9 . That is, in the VOC recovery apparatus 100, a circulation path of heater 6→desorption zone 5→cooler 7→cooling zone 9→heater 6 is formed.

FIG. 2 shows an example in which the VOC (for example, ethyl acetate) adsorption amount of the recovery rotor 2 with the pretreatment adsorption unit 3 is compared with the VOC adsorption amount of the recovery rotor 2 without the pretreatment adsorption unit 3 . . FIG. 2 compares the amount of ethyl acetate adsorbed by using activated carbon, zeolite 13X, high silica zeolite 1000, and Wakkanai diatom shale as impurity adsorbents contained in the pretreatment adsorber 3 . As shown in FIG. 2, when the pretreatment adsorption unit 3 is provided, the VOC adsorption amount of the recovery rotor 2 is larger than when the pretreatment adsorption unit 3 is not provided.

By the way, the Wakkanai Formation diatom shale used for the impurity adsorbent of the present embodiment is shale mainly mined in the Tenboku region of Hokkaido. FIG. 3 shows an example of a comparison of characteristics between the Wakkanai Formation diatom shale and other impurity adsorbent candidates. As shown in FIG. 3, the Wakkanai Formation diatom shale is a porous material with a pore size of about 4 to 20 nm. Wakkanai diatom shale has a larger pore size than zeolite 13X and high silica zeolite 1000, and has excellent adsorption performance for substances having a large molecular size such as 2-ethylhexyl acrylate described later.

In addition, since the pores of the Wakkanai diatom shale are derived from the crystal structure, the pore structure is less likely to be destroyed, is chemically stable, and has heat resistance. Also, as shown in FIG. 3, the Wakkanai Formation diatom shale is less expensive than other impurity adsorbent candidates.

FIG. 4 shows an example of comparison between the amount of VOCs adsorbed by the impurity adsorbent and the amount of impurities adsorbed. However, ethyl acetate was used as an example of VOCs, and 2-ethylhexyl acrylate was used as an example of impurities for comparison. As shown in FIG. 4, it can be seen that the Wakkanai Formation diatom shale has a remarkable property of adsorbing more impurities than the VOCs to be recovered.

<Operation example>
Next, the operation of the VOC recovery device 100 will be explained. FIG. 5 shows an example of a flowchart showing the operation of the VOC recovery device 100. As shown in FIG.

(Step S101)
A drying process for drying the organic solvent is performed in the drying oven 1 . VOCs such as toluene and ethyl acetate volatilize from the organic solvent. Further, impurities such as 2-ethylhexyl acrylate volatilize from the organic solvent. That is, in the drying furnace 1, a mixed gas in which impurities are mixed with VOC is generated.

A mixed gas of VOCs and impurities passes through the pretreatment adsorption section 3 . When the mixed gas passes through the pretreatment adsorption section 3 , impurities are adsorbed in the pores of the Wakkanai Formation diatom shale of the pretreatment adsorption section 3 . That is, impurities are removed from the mixed gas.

(Step S102)
The VOC-containing gas that has passed through the pretreatment adsorption section 3 passes through the adsorption zone 4 of the recovery rotor 2 . VOCs contained in the gas are adsorbed and recovered by the recovery rotor 2 in the adsorption zone 4 .

(Step S103)
The rotor rotates and the rotor surface with attached VOCs is sent to the desorption zone 5 . Heated gas sent from a heater 6 flows through the desorption zone 5 . The heater 6 heats the gas to about 170 degrees. The VOCs are desorbed from the rotor surface by heated gas from heater 6 and flow to cooler 7 located downstream of the rotor.

(Step S104)
The VOCs are condensed to liquid in the cooler 7 and drip into the drain pan. The VOCs are then stored in the recovery container 8 . The VOCs stored in the recovery container 8 are sent to the drying furnace 1 and reused. VOCs that are not condensed in the cooler 7 and remain in a gaseous state are circulated to the cooler 7 via the cooling zone 9 →heater 6 →desorption zone 5 .

<Action/effect>
With the VOC recovery apparatus 100 as described above, the impurities are adsorbed to the Wakkanai Formation diatom shale of the pretreatment adsorption section 3 , so adsorption of impurities to the recovery rotor 2 is suppressed. Therefore, the VOC recovery function of the recovery rotor 2 continues. FIG. 6 shows an example of the VOC adsorption amount in the recovery rotor 2 when impurities are adsorbed and removed by the pretreatment adsorption section 3 . As shown in FIG. 6, it can be seen that the VOC recovery function continues when the pretreatment adsorption unit 3 is present compared to when the pretreatment adsorption unit 3 is absent. Therefore, the frequency of replacing the recovery rotor 2 is reduced, and maintenance costs for the VOC recovery device 100 are reduced.

Moreover, as shown in FIG. 4, the Wakkanai Formation diatom shale has the property of adsorbing more impurities than the VOCs to be recovered. Therefore, adsorption and recovery of VOCs in the pretreatment adsorption section 3 is suppressed, and a decrease in the amount of VOCs recovered in the recovery rotor 2 is suppressed.

In addition, in the case of a VOC recovery apparatus that does not have the pretreatment adsorption unit 3, the recovery rotor 2 adsorbs impurities. In order to desorb impurities from the recovery rotor 2, it is necessary to heat the recovery rotor 2 to a temperature higher than the normal regeneration temperature. When the recovery rotor 2 is heated to a high temperature in this way, the VOC itself adsorbed on the recovery rotor 2 is also chemically decomposed, which may affect the recovery of the VOC. However, with the VOC recovery apparatus 100 described above, the recovery rotor 2 need not be heated to a high temperature, so there is no risk that the VOCs themselves will be chemically decomposed and that VOC recovery will not be affected.

In addition, since the Wakkanai Formation diatom shale is inexpensive, it is possible to reduce the cost of equipment.

A second embodiment of the present invention will be described below. The second embodiment shown below is an example of the embodiment of the present invention, and does not limit the technical scope of the present invention to the following aspects.

<Device configuration>
FIG. 7 shows an example of the outline of the VOC recovery device 100A according to the second embodiment. As shown in FIG. 7, the VOC recovery device 100A includes two pretreatment adsorption units 3A and 3B. The pretreatment adsorption parts 3A and 3B each contain Wakkanai diatom shale. The VOC recovery apparatus 100A also includes motor dampers (hereinafter referred to as MDs) 10A and 10B on the way from the drying furnace 1 to the pretreatment adsorption units 3A and 3B. In addition, the VOC recovery device 100A includes MD10C and MD10D in the middle of the route from the pretreatment adsorption units 3A and 3B to the recovery rotor 2. As shown in FIG.

The VOC recovery apparatus 100A also includes a pretreatment heater 11 and a fan 12 that feed heated gas to the pretreatment adsorption section 3A or 3B. Here, the pretreatment heater 11 is an example of the "heating section" of the present invention. Between the pretreatment heater 11 and the fan 12 and the pretreatment adsorption units 3A and 3B, a circulation path is formed in which the heated gas circulates. be provided.

In addition, the circulation path is provided with an MD 13E that takes in outside air and adjusts the amount of inflow of the outside air. Also, part of the heated gas is sent to the combustion treatment equipment outside the system, and the MD 13F is provided for adjusting the amount of the heated gas sent to the combustion treatment equipment outside the system.

<Operation example>
Next, the operation of the VOC recovery device 100A will be described. An example of a flow chart showing the operation of the VOC recovery device 100A is shown below.

(Step S201)
First, the VOC recovery device 100A opens the MD 10A and closes the MD 10B. Also, the MD 10C is opened and the MD 10D is closed. FIG. 8 shows the VOC recovery device 100A with MDs 10A, 10C open and MDs 10B, 10D closed. Also, the MDs 13A and 13C are closed. With this configuration, the mixed gas in which impurities are mixed with the VOC generated in the drying furnace 1 passes through the pretreatment adsorption section 3A. Impurities including 2-ethylhexyl acrylate are adsorbed in the pores of the Wakkanai Formation diatom shale of the pretreatment adsorption section 3A. That is, impurities are removed from the mixed gas. Then, the VOC-containing gas from which impurities have been removed is sent to the adsorption zone 4 of the recovery rotor 2 . The procedures for VOC recovery and VOC reuse in the recovery rotor 2 are the same as steps S102 to S104.

(Step S202)
After a predetermined time has passed, MDs 10A and 10C are closed and MDs 10B and 10D are opened. FIG. 9 shows the VOC recovery device 100A with MD10A, 10C closed and MD10B, MD10D open. That is, in step S202, the pretreatment adsorption section that adsorbs impurities is switched from 3A to 3B. Therefore, the mixed gas in which impurities are mixed with the VOC generated in the drying furnace 1 passes through the pretreatment adsorption section 3B.

Also, in step S202, the MDs 13A and 13C are opened, and the MDs 13B and 13D are closed. Also, the pretreatment heater 11 and the fan 12 are operated. Then, the outside air taken in by the pretreatment heater 11 is heated to, for example, 300 degrees. The heated outside air is sent to the pretreatment adsorption section 3A to thermally regenerate the pretreatment adsorption section 3A. Therefore, the impurities adsorbed on the pretreatment adsorption part 3A are desorbed by heating.

After a predetermined time has passed, the MDs 10A and 10C are opened again, and the MDs 10B and 10D are closed again. Moreover, MD13A and 13C are closed, and MD13B and MD13D are opened. By such an operation, the pretreatment adsorption section for adsorbing impurities is switched from 3B to 3A. Also, the pretreatment adsorption portion 3B in which impurities are adsorbed is regenerated by heating.

Further, the impurities desorbed in the pretreatment adsorption section 3A or 3B are mixed with the heated gas sent to the pretreatment adsorption section 3A or 3B by the pretreatment heater 11 and the fan 12. FIG. Impurities mixed in the heated gas pass through the MD13F and are sent to the combustion treatment facility outside the system. The impurities are then combusted in an external combustion treatment facility.

As described above, the VOC recovery device 100A switches the pretreatment adsorption section that adsorbs impurities. Further, while one pretreatment adsorption section is adsorbing impurities, the other pretreatment adsorption section is regenerated by heating. Although the VOC recovery apparatus 100A has two systems of pretreatment adsorption units, the number of pretreatment systems is not limited to two, and any number of systems may be used.

<Action/effect>
In the VOC recovery apparatus 100A as described above, since the pretreatment adsorption units 3A and 3B are thermally regenerated, the function of adsorbing impurities in the pretreatment adsorption units 3A and 3B continues. That is, the suppression of adsorption of impurities in the recovery rotor 2 continues, and the VOC recovery function of the recovery rotor 2 continues.

FIG. 10 shows an example of the VOC adsorption amount in the recovery rotor 2 when the pretreatment adsorption section is thermally regenerated. As shown in FIG. 10, it is confirmed that when the pretreatment adsorption section is thermally regenerated, the VOC recovery function is maintained further than when it is not thermally regenerated.

Further, the VOC recovery apparatus 100A as described above does not require replacement of the recovery rotor 2 and the pretreatment adsorption units 3A and 3B. Maintenance costs are thus reduced.

In addition, since Wakkanai diatom shale has heat resistance, the VOC recovery device 100A heats the pretreatment adsorption units 3A and 3B to a temperature (300 degrees) higher than the regeneration temperature (170 degrees) of the recovery rotor 2, Impurities can be desorbed. In other words, the VOC recovery apparatus 100A can preliminarily desorb and remove impurities that cannot be desorbed at the regeneration temperature of the recovery rotor 2 in the pretreatment.

The regeneration temperature (300 degrees) of the pretreatment adsorption units 3A and 3B is the temperature at which the polymerization of impurities such as 2-ethylhexyl acrylate and butyl acrylate is stopped. Therefore, the desorption of impurities from the pretreatment adsorption portions 3A and 3B is promoted, and the degree of regeneration of the pretreatment adsorption portions 3A and 3B is enhanced.

In addition, in the case of a VOC recovery apparatus that does not have the pretreatment adsorption units 3A and 3B, the recovery rotor 2 adsorbs impurities. In order to desorb impurities from the recovery rotor 2, it is necessary to heat the recovery rotor 2 to a temperature higher than the normal regeneration temperature. When the recovery rotor 2 is heated to a temperature higher than the normal regeneration temperature, the VOC itself adsorbed on the recovery rotor 2 is also chemically decomposed, which may affect the recovery of the VOC. However, with the VOC recovery apparatus 100A, there is no need to heat the recovery rotor 2 to a temperature higher than the normal regeneration temperature, so there is no risk of the VOCs themselves being chemically decomposed, and there is no effect on VOC recovery. There is no fear of reaching.

Further, the VOC recovery apparatuses 100 and 100A may include a humidity controller upstream of the pretreatment adsorption section to adjust the relative humidity of the gas flowing into the pretreatment adsorption section. FIG. 11 shows an example of comparison of water adsorption amounts between Wakkanai diatomaceous shale and other diatomaceous earths. As shown in FIG. 11, the Wakkanai Formation diatomaceous shale rapidly absorbs more water molecules than other diatomaceous earths when the relative humidity exceeds approximately 60%. Therefore, when Wakkanai diatom shale is used as the adsorbent of the pretreatment adsorption section, the relative humidity of the gas flowing into the pretreatment adsorption section may be adjusted to, for example, less than 60% by the humidity controller. With such a VOC recovery apparatus 100, 100A, the adsorption of water molecules to the Wakkanai diatom shale is suppressed, and the adsorption of impurities in pores is suppressed from being affected.

Although an example of the preferred embodiment of the present invention has been described above, the present invention is not limited to the illustrated form. It is obvious that a person skilled in the art can conceive various modifications or modifications within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. understood as a thing.

1 Drying furnace 2 Recovery rotor 3, 3A, 3B Pretreatment adsorption part 4 Adsorption zone 5 Desorption zone 6 Heater 7 Cooler 8 Collection container; 9 Cooling zone; 10A, 10B, 10C, 10D, 13A, 13B, 13C, 13D, 13E, 13F Motor damper; 11 Pretreatment heater; 12 Fan;・VOC recovery equipment

Claims (9)

an adsorption recovery unit that adsorbs and recovers VOCs to be recovered;
An adsorbent used for pretreatment for adsorption recovery in the adsorption recovery unit, having resistance at a temperature higher than the regeneration temperature of the adsorption recovery unit, and adsorbing impurities mixed in the VOC to be recovered. an impurity adsorbent;
The impurities are substances other than the VOC to be recovered, and are substances that are not desorbed from the adsorption recovery unit at the regeneration temperature of the adsorption recovery unit when the adsorption recovery unit is regenerated,
The impurity adsorbent has adsorption performance to adsorb more impurities than the VOC,
VOC recovery equipment. Further comprising a heating unit that heats the impurity adsorbent,
The VOC recovery device according to claim 1. The heating unit heats the impurity adsorbent to 300 degrees or higher,
The VOC recovery device according to claim 2. The impurities include 2-ethylhexyl acrylate or butyl acrylate.
The VOC recovery device according to any one of claims 1 to 3. The impurity adsorbent is Wakkanai diatom shale,
5. The VOC recovery device according to any one of claims 1-4. further comprising a plurality of systems connected to the upstream side of the adsorption recovery unit and provided with the impurity adsorbent;
A VOC recovery device according to any one of claims 1 to 5. Further comprising switching means for switching, among the plurality of systems, the system through which the VOC to be recovered passes,
The VOC recovery device according to claim 6. further comprising a humidity controller that adjusts the relative humidity of the gas containing the VOCs to be recovered to less than 60%;
A VOC recovery device according to any one of claims 1 to 7 . an adsorption recovery step in which the adsorption recovery unit adsorbs and recovers VOCs to be recovered;
The adsorbent used for the pretreatment of adsorption recovery in the adsorption recovery step, wherein the impurity adsorbent having resistance at a temperature higher than the regeneration temperature of the adsorption recovery unit is mixed in the VOC to be recovered. an impurity adsorption step of adsorbing impurities that are substances other than VOCs to be recovered and that are substances that are not desorbed from the adsorption recovery unit at the regeneration temperature of the adsorption recovery unit when the adsorption recovery unit is regenerated;
In the impurity adsorption step, the impurities are adsorbed by the impurity adsorbent in a larger amount than the VOCs.
VOC recovery method.

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