JP2018019884A - Decomposition/removal method and decomposition/removal apparatus of hydrogen peroxide gas - Google Patents

Abstract

A method and apparatus for decomposing and removing hydrogen peroxide gas capable of decomposing and removing hydrogen peroxide gas in a working environment chamber to a low concentration in a short time. SOLUTION: A decomposition and removal step of decomposing and removing hydrogen peroxide gas by a catalyst 13 and a humidification step of humidifying the inside of the work environment chamber 10 to a degree of dew condensation are included, so that the hydrogen peroxide gas is catalyzed in the decomposition and removal step. 13 is decomposed and removed by the humidification process and is humidified to the extent that the inside of the work environment chamber 10 is not dewed in the humidification step, thereby increasing the partial pressure of water vapor and increasing the partial pressure of hydrogen peroxide in the work environment chamber 10. Since the hydrogen peroxide gas is promoted to be separated from the wall surface and other members in the inside 10 to form hydrogen peroxide gas, and this hydrogen peroxide gas can be decomposed and removed by the catalyst in the decomposition and removal step. The hydrogen peroxide gas can be decomposed and removed at a low concentration in a short time. [Selection] Figure 1

Description

  The present invention relates to a method and apparatus for decomposing and removing hydrogen peroxide gas that decomposes and removes hydrogen peroxide gas in a working environment chamber.

In the isolator used in the pharmaceutical manufacturing field, and in the safety cabinet used in microbial experiments and virus handling, management of suspended particles and management of microorganisms, fungi, and viruses are important. In the pharmaceutical manufacturing field, it is required to maintain the manufacturing environment (in the working environment chamber) in a sterile state, and the sterility assurance level (SAL) is 10 ⁻⁶ . Further, in the safety cabinet, it is necessary to decontaminate the inside of the apparatus (in the working environment room) in order to prevent the worker from being infected with harmful bacteria and viruses during apparatus maintenance.

  Conventionally, fumigation with formaldehyde gas has been mainly performed as a decontamination method, but formaldehyde is a carcinogenic substance, and its use has been strictly regulated in recent years. On the other hand, as an alternative method of formaldehyde decontamination, decontamination methods using alternative agents such as hydrogen peroxide, peracetic acid and ozone have been studied. Among them, hydrogen peroxide gas is easier to handle than other alternatives, and in the pharmaceutical manufacturing field, many hydrogen peroxide gases have been used for isolator decontamination. Various decontamination methods using hydrogen peroxide have been proposed (see, for example, Patent Document 1).

By the way, in order to perform cell operations in the field of regenerative medicine, complete sterilization in the working environment chamber is indispensable, and hydrogen peroxide gas decontamination is often used for the decontamination. After the hydrogen peroxide gas decontamination, the hydrogen peroxide gas is generally decomposed and removed with a dedicated catalyst so that the concentration in the air is decomposed and removed to 1 ppm so as not to harm humans. However, recently, there has been an increasing demand for lowering to 0.1 ppm for the purpose of further reducing damage to cells.
At the time of decontamination, the atmospheric concentration of hydrogen peroxide gas in the working environment chamber is set to 300 ppm to 1000 ppm. At this time, hydrogen peroxide adheres to other members such as the wall surface of the working environment chamber and the HEPA filter.
Conventional neutralization (decomposition and removal) of hydrogen peroxide gas after decontamination is performed by neutralizing (decomposing and removing) high-concentration hydrogen peroxide gas in the working environment chamber 10 as shown in FIG. This is a system in which the catalyst 2 decomposes and removes it to a concentration of 1/100 to 1/1000, and returns air containing a small amount (ultra-low concentration) of hydrogen peroxide gas to the working environment chamber 10 after the decomposition and removal. there were. In FIG. 3, reference numeral 3 denotes a blower, and reference numeral 4 denotes a control unit.

JP 2002-360672 A

However, the conventional method for decomposing and removing hydrogen peroxide gas after decontamination has the following problems.
That is, first, FIG. 4 shows the relationship between the decrease in the concentration of hydrogen peroxide gas and the neutralization (decomposition and removal) time by the conventional decomposition and removal method. If the hydrogen peroxide gas present in the working environment chamber is at a high concentration, the decomposition and removal effect is high, and the time required for neutralization (decomposition and removal) is relatively fast, but if the concentration is low at 20 ppm or less, the wall surface and HEPA It is affected by hydrogen peroxide adhering to other members such as filters, and it takes a long time to reduce to 1 ppm. Furthermore, when an ultra-low concentration of 0.1 ppm is required, depending on the volume to be decontaminated, there are many cases where it is necessary for 24 hours or more. is there.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method and apparatus for decomposing and removing hydrogen peroxide gas that can decompose and remove hydrogen peroxide gas in a working environment chamber at a low concentration in a short time. And

In order to achieve the above object, the method for decomposing and removing hydrogen peroxide gas of the present invention is a method for decomposing and removing hydrogen peroxide gas in a working environment chamber,
A decomposition and removal step of decomposing and removing the hydrogen peroxide gas with a catalyst; and a humidification step of humidifying the working environment chamber to a degree of dew condensation.

  In the present invention, the hydrogen peroxide gas is decomposed and removed by the catalyst in the decomposition and removal step, and the humidification step is humidified to the extent that no condensation occurs in the working environment chamber, thereby increasing the partial pressure of water vapor. In order to increase the partial pressure, hydrogen peroxide gas is promoted by removing hydrogen peroxide adhering to the walls and other members in the working environment chamber to form hydrogen peroxide gas. This hydrogen peroxide gas is decomposed and removed by the catalyst in the decomposition and removal process. Therefore, the hydrogen peroxide gas in the working environment chamber can be decomposed and removed to a low concentration in a short time.

  Moreover, in the said structure of this invention, after making the said hydrogen peroxide gas into the low concentration of 20 ppm or less, you may perform the said decomposition removal process and the said humidification process.

Here, as described above, if the hydrogen peroxide gas existing in the working environment chamber has a high concentration, the decomposition and removal effect is high, and the time required for the decomposition and removal is relatively fast, but when the concentration is low at 20 ppm or less. It takes a long time to decompose and remove to 1 ppm due to hydrogen peroxide adhering to other members such as the wall surface and HEPA filter.
For this reason, according to the above configuration, the hydrogen peroxide gas can be efficiently decomposed and removed in a short time since the decomposition and removal step and the humidification step are performed after the hydrogen peroxide gas has a low concentration of 20 ppm or less.

  In the configuration of the present invention, the humidification step may be intermittently repeated a predetermined number of times while performing a dehumidification step of dehumidifying the working environment chamber.

  According to such a configuration, the humidity control by humidification in the working environment chamber can be easily performed by intermittently repeating the humidification process a predetermined number of times while performing the dehumidification process. The decomposition and removal time can be shortened, and the concentration of hydrogen peroxide gas in the air can be decomposed and removed to 0.1 ppm.

  Moreover, in the said structure of this invention, you may irradiate an ultraviolet-ray from the germicidal lamp in the said working environment room.

According to such a configuration, the hydrogen peroxide adhering to the wall surface of the working environment chamber and other members is decomposed into OH radicals by ultraviolet rays. Since the OH radical is unstable, it immediately returns to hydrogen peroxide (H ₂ O ₂ ) or decomposes into H ₂ O and H ₂ . Therefore, the decomposition and removal time after the hydrogen peroxide gas decontamination can be shortened, and further, it is very effective for the decomposition and removal reaching an ultra-low concentration of 1 ppm or less.

The hydrogen peroxide gas decomposition and removal apparatus of the present invention is a hydrogen peroxide gas decomposition and removal apparatus for decomposing and removing hydrogen peroxide gas in a working environment chamber,
A lead-in pipe for drawing in hydrogen peroxide gas and air in the working environment chamber;
A catalyst for decomposing and removing the hydrogen peroxide gas drawn in by the lead-in pipe;
A return pipe for returning the hydrogen peroxide gas and air partially decomposed and removed by the catalyst into the working environment chamber;
And a humidifier for humidifying the working environment chamber so as not to condense.

In the present invention, the hydrogen peroxide gas and air in the working environment chamber are drawn in by the inlet pipe, and a part of the drawn hydrogen peroxide gas is decomposed and removed by the catalyst. The process of returning air to the working environment chamber by return piping is repeated.
On the other hand, humidification that humidifies the interior of the work environment to the degree of condensation by the humidifier increases the partial pressure of water vapor and makes it easy to increase the partial pressure of hydrogen peroxide in the work environment room. The removal of the attached hydrogen peroxide is promoted to form hydrogen peroxide gas, which is decomposed and removed by the catalyst, so that the hydrogen peroxide gas in the working environment chamber can be decomposed and removed to a low concentration in a short time. .

In the configuration of the present invention, a concentration sensor that detects the concentration of the hydrogen peroxide gas returned to the working environment chamber by the return pipe;
After the concentration of the hydrogen peroxide gas detected by the concentration sensor becomes a low concentration of 20 ppm or less, the humidifier may be humidified so as not to dew the work environment chamber.

  According to such a configuration, after the concentration of the hydrogen peroxide gas detected by the concentration sensor becomes a low concentration of 20 ppm or less, the humidifier is humidified to such an extent that the working environment chamber is not condensed. Hydrogen peroxide gas can be decomposed and removed over time.

  Further, in the configuration of the present invention, a control unit is provided that controls a humidifying operation for humidifying the working environment chamber to a degree of dew condensation by the humidifier while performing a dehumidifying operation for dehumidifying the working environment chamber by the dehumidifier. May be.

  According to such a configuration, the humidity control by humidification in the working environment chamber is facilitated by controlling the dehumidifier and the humidifier by the control unit and performing the dehumidifying operation intermittently and repeatedly for a predetermined number of times. As a result, the time for decomposing and removing hydrogen peroxide gas can be shortened, and the concentration of hydrogen peroxide gas in the air can be decomposed and removed to 0.1 ppm.

  Moreover, the said structure of this invention WHEREIN: You may provide the germicidal lamp which irradiates an ultraviolet-ray in the said working environment chamber.

According to such a configuration, by irradiating ultraviolet rays from the germicidal lamp into the working environment chamber, hydrogen peroxide adhering to the wall surface of the working environment chamber and other members is decomposed into OH radicals. Since the OH radical is unstable, it immediately returns to hydrogen peroxide (H ₂ O ₂ ) or decomposes into H ₂ O and H ₂ . Therefore, the decomposition and removal time after the hydrogen peroxide gas decontamination can be shortened, and further, it is very effective for the decomposition and removal reaching an ultra-low concentration of 1 ppm or less.

  According to the present invention, the hydrogen peroxide gas is decomposed and removed by the catalyst, and the partial pressure of hydrogen peroxide in the working environment chamber is easily increased by increasing the water vapor partial pressure by humidifying the working environment chamber to the degree of dew condensation. As the hydrogen peroxide gas is promoted by the removal of hydrogen peroxide adhering to the walls and other members in the working environment chamber, and this hydrogen peroxide gas can be decomposed and removed by the catalyst. Gas can be decomposed and removed at low concentration in a short time.

It is a figure which shows schematic structure of the decomposition removal apparatus of the hydrogen peroxide gas which concerns on embodiment of this invention. It is for demonstrating the decomposition | disassembly removal method of the hydrogen peroxide gas which concerns on embodiment of this invention, and shows the relationship between the neutralization (decomposition removal) time of hydrogen peroxide gas, hydrogen peroxide gas concentration, and humidity It is a graph. It is a figure which shows schematic structure of the conventional decomposition removal apparatus of hydrogen peroxide gas. It is a graph which shows the relationship between the neutralization (decomposition removal) time of the conventional hydrogen peroxide gas, and hydrogen peroxide gas concentration.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a hydrogen peroxide gas decomposition / removal apparatus according to the present embodiment. In FIG. 1, reference numeral 10 denotes a work environment room. The work environment chamber 10 is decontaminated using hydrogen peroxide gas. Examples of the work environment chamber 10 include a work space of an isolator used in the pharmaceutical manufacturing field, a microbe experiment, and a virus. The working space of the safety cabinet used at the time of handling is mentioned, However It is not restricted to this.
The working environment chamber 10 is peroxidized by a hydrogen peroxide gas decomposition / removal device (hereinafter abbreviated as a decomposition / removal device) 11 according to the present embodiment after decontamination with hydrogen peroxide gas. Hydrogen gas is decomposed and removed.

  The decomposition / removal device 11 includes a lead-in pipe 12, a catalyst 13, a return pipe 14, a concentration sensor 15, a humidity sensor 16, a humidifier 17, a dehumidifier 18, a blower 19, a germicidal lamp 20, and a humidifier. A controller 21 and a control unit 22 are provided.

The lead-in pipe 12 is for drawing the hydrogen peroxide gas and air in the work environment chamber 10 into the decomposition / removal device 11, and one end of the lead-in pipe 12 is provided on the wall forming the work environment chamber 10. The other end is connected to the dehumidifier 18.
The dehumidifier 18 may be a moisture adsorbent such as a dehumidifying agent, or may be configured to introduce compressed air into the work environment chamber 10 by a compressor to make the work environment chamber 10 a dry area. Or the structure which introduce | transduces nitrogen and dry air into the work environment chamber 10 from the outside, and makes the said work environment chamber 10 the dry area may be sufficient.

The dehumidifier 18 is for dehumidifying the inside of the work environment chamber 10, is electrically connected to a control unit (PLC) 22, and is controlled by the control unit 22.
On the downstream side of the dehumidifier 18, a container 13a in which the catalyst 13 is accommodated is provided, and the dehumidifier 18 is connected to the container 13a by a pipe.
As the catalyst 13, for example, a reducing agent such as platinum can be used, and the catalyst 13 is accommodated in a container 13a. The hydrogen peroxide gas is decomposed and removed into water and oxygen by a reduction reaction by the catalyst 13.
In addition, a blower 19 is provided on the downstream side of the container 13a in which the catalyst 13 is stored, and the container 13a is connected to an intake port of the blower 19 by a pipe. The blower 19 is electrically connected to the control unit 22 and is controlled by the control unit 22.
The return pipe 14 returns the hydrogen peroxide gas and air, which has been partially decomposed and removed by the catalyst 13, to the work environment chamber 10. One end of the return pipe 14 is connected to the humidifier 17, and the like. The end portion is connected to an inlet provided in a wall forming the work environment chamber 10.

The humidifier 17 is for humidifying the inside of the work environment chamber 10, and is connected to a blower opening of a blower 19 provided on the downstream side of the catalyst 13 in the decomposition / removal device 11.
The humidifier 17 is electrically connected to the humidification controller 21 and is controlled by the humidification controller 21. Further, the humidity sensor 16 is electrically connected to the humidification controller 21.
Further, the humidifier 17 humidifies the work environment chamber 10 so as not to condense after the concentration of the hydrogen peroxide gas in the work environment chamber 10 detected by the concentration sensor 15 becomes a low concentration of 20 ppm or less. Thus, it can be controlled by the humidification controller 21.
For example, the humidification controller 21 controls the humidifier 17 based on the humidity in the work environment chamber 10 detected by the humidity sensor 16 to adjust the relative humidity in the work environment chamber 10 to 60 to 80%. It is possible. The humidification controller 21 is electrically connected to the control unit 22, and the humidifier 17 can be controlled by the humidification controller 21 based on a control signal from the control unit 22.

The concentration sensor 15 is for detecting the concentration of the hydrogen peroxide gas in the work environment chamber 10, and is attached to the wall forming the work environment chamber 10. The concentration sensor 15 is electrically connected to the control unit 22. The concentration sensor 15 can detect the concentration of the hydrogen peroxide gas returned to the work environment chamber 10 by the return pipe 14.
The humidity sensor 16 detects the humidity in the work environment chamber 10 and is attached to the wall forming the work environment chamber 10. The humidity sensor 16 is electrically connected to the humidification controller 21.

In the decomposition / removal device 11 having such a configuration, when the blower 19 is driven by the control unit 22, the container 13 a containing the catalyst 13, the dehumidifier 18, and the lead-in pipe 12 are sequentially connected to the intake port of the blower 19. Furthermore, since the humidifier 17 and the return pipe 14 are connected in order to the air outlet of the blower 19, the hydrogen peroxide gas and air are drawn into the decomposition / removal device 11 from the work environment chamber 10, and the hydrogen peroxide gas is converted into a catalyst. After being disassembled and removed by 13, the work environment chamber 10 is returned together with air.
At this time, the humidifier 17 and the dehumidifier 18 are controlled as appropriate by the humidification controller 21 and the control unit 22. For example, while performing a dehumidifying operation for dehumidifying the inside of the working environment chamber 10, a humidifying operation for humidifying the inside of the working environment chamber 10 to a degree of dew condensation can be intermittently repeated a predetermined number of times.
Further, in the intermittent operation control of the humidifying operation by the humidifier 17, the humidifying operation time can be automatically controlled with a set time preset in the control unit 22. The set time can be set each time depending on the volume and shape of the work environment chamber 10.

The germicidal lamp 20 is for irradiating the work environment chamber 10 with ultraviolet rays, and is attached to a wall forming the work environment chamber 10. The germicidal lamp 20 is electrically connected to the control unit 22 and is controlled by the control unit 22.
The germicidal lamp 20 is driven by the control unit 22 when the concentration sensor 15 detects that the concentration of the hydrogen peroxide gas in the working environment chamber 10 has reached a low concentration of, for example, about 20 ppm, and the working environment chamber 10 The inside can be irradiated with ultraviolet rays. The germicidal lamp 20 can always irradiate the work environment chamber 10 with ultraviolet rays by the control unit 22.

Further, the operation of the humidifier 17 and the ultraviolet irradiation by the sterilizing lamp 20 can be started from a state in which the hydrogen peroxide gas immediately after the decontamination operation in the work environment chamber 10 is at a high concentration. Furthermore, when the hydrogen peroxide gas concentration in the working environment chamber 10 is equal to or lower than a preset neutralization completion concentration (for example, 0.1 ppm), the operation completion can be automatically controlled automatically. Yes.
Further, when the concentration sensor 15 detects that the hydrogen peroxide gas has a low concentration of 20 ppm or less, it is possible to automatically control the operation of the humidifier 17 and the ultraviolet irradiation by the germicidal lamp 20. Furthermore, the concentration sensor 15 can be omitted by setting the start time and completion time of the operation of the humidifier 17 and the ultraviolet irradiation of the germicidal lamp 20 in advance.

Next, an example of a method for decomposing and removing the hydrogen peroxide gas after the decontamination operation in the work environment chamber 10 by using such a decomposition and removal apparatus 11 will be described.
First, when the decomposition and removal apparatus 11 is activated, the blower 19 and the dehumidifier 18 are driven by the control unit 22. Note that the dehumidifier 18 is always kept in an operating state while the decomposition and removal apparatus 11 is in operation.
When the blower 19 is driven, the hydrogen peroxide gas and air are drawn into the decomposition / removal device 11 from the working environment chamber 10 through the drawing pipe 12, and the hydrogen peroxide gas is decomposed and removed by the catalyst 13, and then the air enters the working environment chamber 10. Return with. At this time, after being dehumidified by the dehumidifier 18, the hydrogen peroxide gas and air after being partially decomposed and removed are returned to the working environment chamber 10.
Such a process (dehumidification decomposition removal process) is repeatedly performed for a predetermined time (for example, about 5 minutes).
While the hydrogen peroxide gas is being decomposed and removed and dehumidified, the concentration sensor 15 always detects the concentration of the hydrogen peroxide gas in the work environment chamber 10 and the humidity sensor 16 detects the concentration in the work environment chamber 10. Detect humidity.

When the dehumidifying operation by the dehumidifier 18 elapses for a predetermined time (for example, about 5 minutes), the humidifier 17 is driven by the controller 22. The humidifier 17 is driven and controlled by the humidification controller 21 based on a drive signal from the control unit 22.
And based on the humidity in the work environment chamber 10 detected by the humidity sensor 16, the humidification controller 21 controls the humidifier 17, and adjusts the relative humidity in the work environment chamber 10 to 60 to 80%. Such a process (humidification process) is repeatedly performed for a predetermined time (for example, about 25 minutes), and the hydrogen peroxide gas is decomposed and removed by the catalyst 13 during the humidification process (decomposition removal process).
By driving the humidifier 17 and humidifying the work environment chamber 10 to the degree of dew condensation (humidification process), hydrogen peroxide adhering to the wall surface of the work environment chamber 10 and other members is removed. The hydrogen peroxide gas is decomposed and removed by the catalyst 13.
In addition, the concentration sensor 15 always detects the concentration of the hydrogen peroxide gas in the working environment chamber 10 while performing the decomposition removal (decomposition removal step) and the humidification (humidification step) of the hydrogen peroxide gas, and the humidity. The sensor 16 detects the humidity in the work environment chamber 10. Even during the humidifying operation, the dehumidifier 18 operates without stopping.

When the humidifying operation by the humidifier 17 elapses for a predetermined time (for example, about 25 minutes), that is, when the humidifying process is performed for a predetermined time, the driving of the humidifier 17 is temporarily stopped by the control unit 22, and the dehumidifying decomposition removing process described above is performed. After that, the above-described humidification step and decomposition / removal step are further performed for a predetermined time.
When the concentration of the hydrogen peroxide gas in the working environment chamber 10 becomes, for example, 0.1 ppm or less by repeating such a dehumidifying decomposition removing process, the humidifying process, and the decomposition removing process sequentially a predetermined number of times, the control unit 22 The blower 19, the dehumidifier 18 and the humidifier 17 are automatically stopped. That is, the decomposition / removal device 11 is automatically stopped.

  Further, ultraviolet rays may be irradiated into the work environment chamber 10 from the germicidal lamp 20 provided in the work environment chamber 10 while the dehumidification decomposition removal step, the humidification step, and the decomposition removal step are sequentially performed a predetermined number of times. . In this case, the control unit 22 controls the germicidal lamp 20 to irradiate ultraviolet rays.

In addition to the method of decomposing and removing the hydrogen peroxide gas in the work environment chamber 10 by the process as described above, it may be decomposed and removed by the following method.
For example, the dehumidification decomposition removal process, the humidification process, and the decomposition removal process as described above may be performed continuously from the beginning to the end, or hydrogen peroxide gas is added to the catalyst 13 while performing the dehumidification decomposition removal process continuously. When the hydrogen peroxide gas becomes a low concentration of 20 ppm or less by decomposing and removing by the above (decomposing and removing step), the humidifier 17 is driven to humidify the work environment chamber 10 so as not to condense (humidification). Process).
In this case, after the hydrogen peroxide gas is reduced to a low concentration of 20 ppm or less, the working environment chamber 10 is irradiated with ultraviolet rays from the germicidal lamp 20 and is oxidized on the wall surface of the working environment chamber 10 and other members. Hydrogen may be decomposed and removed, or ultraviolet rays may be constantly irradiated from the beginning to the end.

  As described above, according to the present embodiment, the hydrogen peroxide gas is decomposed and removed by the catalyst 13 in the decomposition and removal step, and the working environment chamber 10 is humidified to the extent that no condensation occurs in the humidification step. In order to increase the pressure, the partial pressure of hydrogen peroxide in the work environment chamber 10 is likely to increase, and the release of hydrogen peroxide adhering to the wall surface and other members in the work environment chamber 10 is promoted to produce hydrogen peroxide gas. Since the hydrogen peroxide gas can be decomposed and removed by the catalyst 13 in the decomposition and removal step, the hydrogen peroxide gas in the working environment chamber 10 can be decomposed and removed at a low concentration in a short time.

Further, the hydrogen peroxide gas can be efficiently decomposed and removed in a short time by reducing the concentration of the hydrogen peroxide gas to a low concentration of 20 ppm or less and then performing the decomposition removal step and the humidification step.
Furthermore, humidity control by humidification in the work environment chamber 10 can be easily performed by performing the dehumidification operation of dehumidifying the inside of the work environment chamber 10 repeatedly by repeating the humidification process a predetermined number of times. The decomposition and removal time of hydrogen peroxide gas can be shortened, and the concentration of hydrogen peroxide gas in the air can be decomposed and removed to 0.1 ppm.
Further, by irradiating ultraviolet rays from the germicidal lamp 20 into the work environment chamber 10, hydrogen peroxide adhering to the wall surface of the work environment chamber 10 and other members is decomposed into OH radicals. Since the OH radical is unstable, it immediately returns to hydrogen peroxide (H ₂ O ₂ ) or decomposes into H ₂ O and H ₂ . Therefore, the decomposition and removal time after the hydrogen peroxide gas decontamination can be shortened, and further, it is very effective for the decomposition and removal reaching an ultra-low concentration of 1 ppm or less.

Next, experimental examples of the method for decomposing and removing hydrogen peroxide gas according to the present embodiment will be described.
As Experimental Example 1, after performing the dehumidification decomposition removal process first, the humidification process and the decomposition removal process (hereinafter abbreviated as the humidification decomposition removal process) were intermittently performed four times. The first dehumidifying and decomposing step was performed for about 5 minutes, the dehumidifying and decomposing step was performed for about 25 minutes, and the intermittent time was about 5 minutes. Moreover, the dehumidification decomposition removal process was performed also during the intermittent time, and also the dehumidification decomposition removal process was continued after the humidification decomposition removal process.

  Moreover, as Experimental Example 2, after the dehumidification decomposition removal process was first performed for about 5 minutes, the humidification decomposition removal process was continuously performed for about 2 hours. Moreover, the dehumidification decomposition removal process was performed with this humidification decomposition removal process. Furthermore, the dehumidification decomposition removal process continued after the humidification decomposition removal process.

  On the other hand, as a comparative example, the conventional method for decomposition and removal of hydrogen peroxide gas, that is, without performing any of the dehumidification decomposition removal step and the humidification decomposition removal step, only the decomposition removal by the catalyst was performed.

In addition, the volume of the working environment chamber in the experimental examples 1 and 2 and the comparative example is about 0.2 m ³ .

These results are shown in FIG. In the graph shown in FIG. 2, the horizontal axis represents the neutralization elapsed time (decomposition removal elapsed time), the left vertical axis represents the concentration of hydrogen peroxide gas, and the right vertical axis represents the (relative) humidity of the working environment chamber.
As shown in the graph of FIG. 2, the time required to neutralize (decompose and remove) 1 ppm of hydrogen peroxide gas to 0.3 ppm was 1 hour in the conventional method (comparative example). In Experimental Example 2, it took only about 30 minutes, and the time could be shortened to about ½.
Further, the neutralization time for the hydrogen peroxide gas to reach 0.1 ppm did not decrease from 0.3 ppm even after 3 hours in the conventional method (comparative example), but in the experimental example 1, about 1 hour and 40 minutes. In Example 2, the hydrogen peroxide gas reaches 0.1 ppm in about 2 hours and 10 minutes.

DESCRIPTION OF SYMBOLS 10 Working environment room 11 Decomposition removal apparatus 12 Lead-in piping 13 Catalyst 14 Return piping 15 Concentration sensor 16 Humidity sensor 17 Humidifier 18 Dehumidifier 19 Blower 20 Sterilization lamp 21 Humidification controller 22 Control part

Claims (8)

A method for decomposing and removing hydrogen peroxide gas in a working environment chamber,
A decomposition removal step of decomposing and removing the hydrogen peroxide gas with a catalyst;
A humidifying step of humidifying the working environment chamber to a degree of dewing;
A method for decomposing and removing hydrogen peroxide gas, comprising:   2. The method for decomposing and removing hydrogen peroxide gas according to claim 1, wherein the decomposition and removal step and the humidifying step are performed after the hydrogen peroxide gas has a low concentration of 20 ppm or less.   3. The method for decomposing and removing hydrogen peroxide gas according to claim 1, wherein the humidifying step is intermittently repeated a predetermined number of times while the dehumidifying step of dehumidifying the working environment chamber is performed.   The method for decomposing and removing hydrogen peroxide gas according to any one of claims 1 to 3, wherein the working environment chamber is irradiated with ultraviolet rays from a germicidal lamp. A hydrogen peroxide gas decomposition / removal device for decomposing and removing hydrogen peroxide gas in a working environment chamber,
A lead-in pipe for drawing in hydrogen peroxide gas and air in the working environment chamber;
A catalyst for decomposing and removing the hydrogen peroxide gas drawn in by the lead-in pipe;
A return pipe for returning the hydrogen peroxide gas and air partially decomposed and removed by the catalyst into the working environment chamber;
An apparatus for decomposing and removing hydrogen peroxide gas, comprising a humidifier that humidifies the working environment chamber to a degree of dew condensation. A concentration sensor for detecting the concentration of the hydrogen peroxide gas returned to the working environment chamber by the return pipe;
6. The hydrogen peroxide gas detected by the concentration sensor is humidified to such an extent that the humidifier does not condense the work environment chamber after the concentration of the hydrogen peroxide gas becomes a low concentration of 20 ppm or less. Hydrogen peroxide gas decomposition and removal equipment.   6. The apparatus according to claim 5, further comprising: a control unit that controls a humidifying operation in which the humidifying unit humidifies the inside of the working environment chamber without dew condensation while the dehumidifying device performs a dehumidifying operation in which the working environment chamber is dehumidified. Or the apparatus for decomposing and removing hydrogen peroxide gas according to 6.   The apparatus for decomposing and removing hydrogen peroxide gas according to any one of claims 5 to 7, further comprising a germicidal lamp for irradiating ultraviolet rays in the working environment chamber.

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