Ozone scrubber, ozone removal method, aldehyde collection device, and aldehyde collection method

Abstract

The present invention aims to prevent deliquescence of an ozone remover in an ozone adsorbent in an ozone scrubber, an ozone removal method, an aldehyde trapping device, and an aldehyde trapping method, thereby suppressing clogging of the ozone scrubber and the appearance of ghost peaks in the aldehyde measurement results. [Solution] The ozone adsorbent (8) of the ozone scrubber (2) is an ozone removing agent that does not deliquesce even at high temperatures and high humidity, by carrying 3,3',5,5'-tetramethylbenzidine on a diatomaceous earth carrier. The ozone scrubber (2) is connected to an aldehyde collector (3), and the aldehyde collector (3) is connected to a suction pump (6). By operating the suction pump (6), ozone is adsorbed in the ozone scrubber (2) and aldehyde is adsorbed in the aldehyde collector (3).

Description

[Technical Field]

[0001] The present invention relates to an ozone scrubber and an aldehyde trapping device equipped with an ozone scrubber, and further relates to a method for removing ozone and a method for trapping aldehyde, which are method inventions. [Background technology]

[0002] One method for measuring lower aldehydes (formaldehyde, acetaldehyde, etc.) in indoor and atmospheric environments is the solid collection-HPLC (high performance liquid chromatography) method. That is, aldehydes in the air are collected using an aldehyde collector with an aldehyde adsorbent and then analyzed by HPLC. The analysis results are displayed on a chromatogram after processing the electrical signals sent from analytical equipment. For solid collection of aldehydes, an aldehyde collector filled with silica gel impregnated with DNPH (2,4-dinitrophenylhydrazine) is generally used.

[0003] It has been reported that when sampling in the atmospheric environment, the presence of ozone can cause effects such as the detection of ghost peaks and a decrease in the peak area value of formaldehyde.

[0004] To reduce the impact of ozone, in atmospheric environmental measurements, an ozone scrubber containing an ozone remover is connected to the inlet of an aldehyde collector filled with DNPH-impregnated silica gel, and ozone is removed. Conventional ozone scrubbers widely use potassium iodide as a reactive reagent with ozone. Patent Document 1 discloses an aldehyde collection device in which an ozone scrubber filled with potassium iodide as an ozone remover is connected to the inlet of the aldehyde collector. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-213861 Summary of the Invention [Problem to be solved by the invention]

[0006] The potassium iodide used in conventional ozone scrubbers is deliquescent. Therefore, when used in rainy weather or in a humid environment, the potassium iodide deliquesces, and the dissolved liquid may dissolve and flow into the aldehyde collector located downstream of the suction air.

[0007] Figure 2(a) shows a chromatogram of the measurement results obtained using an aldehyde collection device equipped with an ozone scrubber filled with potassium iodide. The horizontal axis represents retention time (min), and the vertical axis represents the response from the detector, i.e., electrical signal intensity (mAU). A formaldehyde peak, P1, appears between retention times of 4.5 and 5.0 minutes, and an acetaldehyde peak, P2, appears between retention times of 6.0 and 6.5 minutes. In addition, a ghost peak, P3, appears between retention times of 5.5 and 6.0 minutes. There is concern that the appearance of this ghost peak, P3, may affect the aldehyde analysis results.

[0008] Another issue is that potassium iodide deliquesces, causing clogging in the ozone scrubber and making it difficult to suck it up using a suction pump.

[0009] An object of the present invention is to provide an ozone scrubber and an ozone removal method that can prevent clogging and maintain ozone removal performance without leaching out the ozone removing agent inside the ozone scrubber, even in rainy weather or in a high-humidity environment. Another object of the present invention is to provide an aldehyde collection device and a collection method that can suppress the appearance of ghost peaks on a chromatogram and the decrease in the formaldehyde peak area when measuring aldehydes in the atmosphere, even in rainy weather or in a high-humidity environment. [Means for solving the problem]

[0010] To solve the above-mentioned problems, the ozone scrubber of the present invention houses an ozone adsorbent made of diatomaceous earth carrier carrying 3,3',5,5'-tetramethylbenzidine in a scrubber case. This eliminates leaching of the ozone removing agent during rainy weather or in high-humidity environments, and prevents clogging of the ozone scrubber and a decrease in ozone removing performance.

[0011] In one embodiment of the ozone scrubber, the scrubber case is made of a light-shielding material, which can prevent the performance of the ozone adsorbent from being deteriorated by exposure to sunlight.

[0012] The ozone removal method of the present invention removes ozone from the atmosphere by passing the atmosphere through an ozone adsorbent made of diatomaceous earth carrier carrying 3,3',5,5'-tetramethylbenzidine, thereby achieving the same effects as those achieved by using the ozone scrubber described above.

[0013] In one embodiment of the ozone removal method, the ozone adsorbent is shielded from external light by a light-shielding member, thereby achieving the same effect as that achieved by configuring the scrubber case with the above-mentioned light-shielding member.

[0014] The aldehyde collection device according to the present invention comprises a suction pump that sucks in air, an aldehyde collector connected directly or indirectly to the suction pump, and an ozone scrubber connected directly or indirectly to the suction port of the aldehyde collector. The ozone scrubber is constructed by housing an ozone adsorbent, which is made of a diatomaceous earth carrier supporting 3,3',5,5'-tetramethylbenzidine, in a scrubber case.

[0015] This configuration provides the same effects as those obtained when using the ozone scrubber described above, and also suppresses problems such as the appearance of ghost peaks and reduction in peak area caused by the ozone removing agent of the ozone scrubber flowing into the aldehyde collector.

[0016] In one embodiment of the aldehyde trapping device, DNPH (2,4-dinitrophenylhydrazine)-impregnated silica gel is packed in the aldehyde trap.

[0017] In one embodiment of the aldehyde collection device, the scrubber case is made of a light-shielding material, which can prevent the performance of the ozone adsorbent from deteriorating due to exposure to sunlight.

[0018] The method for capturing aldehyde according to the present invention includes the steps of: removing ozone from the atmosphere by passing the atmosphere through an ozone adsorbent comprising a diatomaceous earth carrier carrying 3,3',5,5'-tetramethylbenzidine; and sucking the ozone-removed atmosphere into an aldehyde collector to capture aldehyde.

[0019] This configuration provides the same effects as those obtained when using the ozone scrubber described above, and also suppresses problems such as the appearance of ghost peaks and reduction in peak area caused by the ozone removing agent of the ozone scrubber flowing into the aldehyde collector.

[0020] In one embodiment of the aldehyde trapping method, DNPH (2,4-dinitrophenylhydrazine)-impregnated silica gel is used in the step of trapping aldehyde.

[0021] In one embodiment of the aldehyde trapping method, the ozone adsorbent is shielded from external light in the ozone removal step, thereby preventing performance degradation of the ozone adsorbent due to exposure to sunlight. [Effects of the Invention]

[0022] According to the ozone scrubber and ozone removal method of the present invention, the ozone removing agent does not deliquesce or dissolve, even in rainy weather or in a humid atmospheric environment, so clogging of the ozone scrubber can be prevented and ozone removal performance can be maintained.

[0023] Furthermore, the aldehyde trapping device and aldehyde trapping method according to the present invention, like the invention of an ozone scrubber, can prevent clogging of the ozone scrubber, maintain ozone removal performance, and eliminate the influence of eluted ozone removing agents on the aldehyde trap, as in the conventional case. For example, it can suppress a decrease in the formaldehyde peak area or the occurrence of ghost peaks. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is an overall view of an aldehyde trapping device equipped with an ozone scrubber according to an embodiment of the present invention. [Figure 2] chromatograms showing the measurement results of aldehydes collected by an aldehyde collection device, where (a) is a chromatogram when a conventional ozone adsorbent carrying potassium iodide is used as an ozone remover, and (b) is a chromatogram when an ozone adsorbent carrying 3,3',5,5'-tetramethylbenzidine according to the present invention is used as an ozone remover. DETAILED DESCRIPTION OF THE INVENTION

[0025] [Embodiments of the ozone scrubber and aldehyde trapping device] An embodiment of an ozone scrubber and an aldehyde trapping device according to the present invention will be described with reference to FIGS. 1 and 2. FIG.

[0026] Fig. 1 is an overall view of an aldehyde trapping apparatus 1. In Fig. 1, the aldehyde trapping apparatus 1 is configured to include an ozone scrubber 2, an aldehyde trapping device 3, and a suction pump 6. A pump connection port 32 of the aldehyde trapping device 3 is connected to a suction hose 5 connected to the suction pump 6. A pump connection port 22 of the ozone scrubber 2 is connected to an intake port 31 of the aldehyde trapping device 3.

[0027] The ozone scrubber 2 has an ozone adsorbent 8 stored (filled) in a cylindrical scrubber case 20, and each case is replaceable as a cartridge. The direction of arrow A1 is the air flow direction, and a lid 23 is attached to the upstream end of the scrubber case 20 in the air flow direction A1. An intake tube 24 into which an air intake port 21 opens is formed integrally with the lid 23. A pump connection port 22 is formed at the downstream end of the scrubber case 20 in the air flow direction A1. The interior of the scrubber case 20 forms a suction path where air taken in from the intake port 21 passes through the ozone adsorbent 8 and is discharged from the pump connection port 22.

[0028] The ozone adsorbent 8 is an important component of the present invention and is formed by supporting 3,3',5,5'-tetramethylbenzidine on a diatomaceous earth carrier. The scrubber case 20 is formed of an opaque material that blocks light, such as an opaque black resin. This prevents the ozone adsorbent 8 from being exposed to external light such as sunlight.

[0029] Like the ozone scrubber 2, the aldehyde collector 3 is also a cartridge-type device that allows each case to be replaced, and an aldehyde adsorbent 38 is stored (filled) in a cylindrical collection case 30. The direction of arrow A2 is the air flow direction, and a lid 33 is attached to the upstream end of the aldehyde collector 3 in the air flow direction A2. An inlet tube 34 having the above-mentioned inlet 31 is formed in the lid 33. The above-mentioned pump connection port 32 is formed at the downstream end of the collection case 30 in the air flow direction A2. Inside the collection case 30, a suction path is formed in which air taken in from the inlet 31 passes through the aldehyde adsorbent 38 and is discharged from the pump connection port 32.

[0030] The aldehyde adsorbent 38 disposed in the collection case 30 is made of a porous carrier such as silica gel, which carries DNPH (2,4-dinitrophenylhydrazine).

[0031] In the aldehyde collector 3, DNPH is desorbed with an organic solvent such as acetonitrile (not shown), and the desorbed liquid is analyzed by an analytical instrument such as HPLC.

[0032] [Ozone removal method and aldehyde collection method] In FIG. 1, the aldehyde collection device 1 is installed at a location where lower aldehydes are to be measured in an indoor or atmospheric environment. As test conditions in the laboratory, a mist-like sample gas is sampled under high temperature and high humidity conditions, for example, at a temperature of 40°C.

[0033] By driving the suction pump 6 , the air (sample gas) is sucked into the scrubber case 20 through the suction port 21 of the ozone scrubber 2 .

[0034] In the scrubber case 20, the air passes through the ozone adsorbent 8 in the air flow direction A1, and the ozone in the sucked air is adsorbed by the ozone adsorbent 8.

[0035] The intake air from which ozone has been removed flows from the pump connection port 22 of the ozone scrubber 2 through the suction port 31 of the aldehyde collector 3 and into the collection case 30 .

[0036] In the collection case 30, the intake air passes through the aldehyde adsorbent 38 in the air flow direction A2, whereby the aldehyde is adsorbed.

[0037] The collected aldehydes are derivatized with DNPH. The DNPH is desorbed with an organic solvent such as acetonitrile, and the desorbed solution is analyzed by an analytical instrument such as HPLC. The analytical results are displayed as a chromatogram by processing the electrical output signal from the analytical instrument.

[0038] Figure 2(b) is a chromatogram showing the results of analyzing the collected aldehyde using the same detector as in Figure 2(a) when the aldehyde trapping device 1 according to the present invention shown in Figure 1 is operated under the same conditions (environment) as in Figure 2(a) of the conventional example. That is, this chromatogram shows the results of sampling using mist-like sample gas at a temperature of 40°C. The horizontal axis shows retention time (min), and the vertical axis shows the response from the detector, i.e., electrical signal intensity (mAU).

[0039] In Figure 2(b), a formaldehyde peak P1 appears between retention times 4.5 and 5.0 minutes, and an acetaldehyde peak P2 appears between retention times 6.0 and 6.5 minutes, similar to Figure 2(a). However, the ghost peak P3 seen in Figure 2(a) does not appear.

[0040] In other words, even when sampling is performed under the same high-temperature, high-humidity conditions as in the conventional example, when 3,3',5,5'-tetramethylbenzidine is used as the ozone remover, deliquescence does not occur, and the ghost peak P3 caused by deliquescence as shown in Figure 2(a) does not appear. This allows for accurate measurement of aldehydes.

[0041] Furthermore, for the formaldehyde peak P1, the present embodiment shown in Fig. 2(b) maintains a higher peak height (peak area) than the conventional example shown in Fig. 2(a), which indicates that the reduction in the formaldehyde peak area is more efficiently suppressed than in the conventional example.

[0042] In Figures 2(a) and (b), a large peak P0 preceding the formaldehyde peak P1 appears between retention times of 2.5 and 3.5 minutes. This peak P0 is a peak that detects DNPH (2,4-dinitrophenylhydrazine) used in the aldehyde adsorbent 38 in the aldehyde collector 3 in Figure 1.

[0043] As described above, with the ozone scrubber 2 and ozone removal method according to this embodiment, even in rainy weather or in a humid atmospheric environment, the ozone removing agent 3,3',5,5'-tetramethylbenzidine does not deliquesce or dissolve, so clogging of the ozone scrubber 2 can be prevented and ozone removal performance can be maintained.

[0044] Furthermore, according to the aldehyde trapping device 1 and the aldehyde trapping method of this embodiment, as in the case of the ozone scrubber 2, clogging of the ozone scrubber can be prevented, ozone removal performance can be maintained, and the influence of the eluted ozone removing agent on the aldehyde trapping device 3, as in the conventional case, can be eliminated. In other words, it is possible to suppress a decrease in the peak area of ​​formaldehyde or the occurrence of ghost peaks.

[0045] [Other embodiments] (1) In the aldehyde trapping device 1 of FIG. 1, the ozone scrubber 2 and the aldehyde trapping device 3 are directly connected, but they may also be connected indirectly via an air circulation pipe or the like.

[0046] (2) In the aldehyde trapping device 1 of FIG. 1, the aldehyde trap 3 is connected to the suction pump 6 via the suction hose 5, but it is also possible to connect it directly.

[0047] (3) The ozone scrubber 2 according to the present invention is not limited to the configuration connected to the aldehyde collector 3 shown in FIG. 1, but can also be connected to a collector of other gases and used to measure gases other than aldehydes.

[0048] Each embodiment is presented as an example and is not intended to limit the scope of the invention. These novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0049] 1. Aldehyde collection device 2. Ozone Scrubber 3 Aldehyde collector 6. Suction pump 8 Ozone adsorbent 38 Aldehyde Adsorbent P1 Formaldehyde peak P2 Acetaldehyde peak P3 Ghost Peak

Claims

1. An ozone scrubber in which an ozone adsorbent made of diatomaceous earth carrier carrying 3,3',5,5'-tetramethylbenzidine is housed in a scrubber case.

2. 2. The ozone scrubber according to claim 1, wherein the scrubber case is formed of a light-shielding material.

3. An ozone removal method for removing ozone from the atmosphere by passing the atmosphere through an ozone adsorbent comprising a diatomaceous earth carrier carrying 3,3',5,5'-tetramethylbenzidine.

4. 4. The ozone removal method according to claim 3, wherein the ozone adsorbent is shielded from external light by a light-shielding member.

5. a suction pump that sucks in atmospheric air; and an aldehyde collector that is directly or indirectly connected to the suction pump; an ozone scrubber connected directly or indirectly to the suction port of the aldehyde collector; The ozone scrubber is an aldehyde collection device configured by housing an ozone adsorbent, which is made of diatomaceous earth carrier and supports 3,3',5,5'-tetramethylbenzidine, in a scrubber case.

6. 6. The aldehyde trapping device according to claim 5, wherein the aldehyde trap has a trapping case filled with DNPH (2,4-dinitrophenylhydrazine)-impregnated silica gel.

7. The aldehyde trapping device according to claim 5 or 6, wherein the scrubber case is formed of a light-blocking material.

8. aspiration of air containing ozone; removing ozone from the atmosphere by passing the atmosphere through an ozone adsorbent comprising a diatomaceous earth carrier carrying 3,3',5,5'-tetramethylbenzidine; and a step of sucking the air from which the ozone has been removed into an aldehyde collector and collecting the aldehyde.

9. 9. The method for trapping aldehyde according to claim 8, wherein the step of trapping aldehyde uses silica gel impregnated with DNPH (2,4-dinitrophenylhydrazine).

10. 10. The method for trapping aldehyde according to claim 8, wherein the ozone adsorbent is shielded from external light in the step of removing ozone.

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