JPH10272333A - Gas purifying method, air cleaning method and apparatus for them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To purify crude gas by a simple means to obtain a high purity gas. SOLUTION: This gas purifying apparatus is an air cleaning apparatus wherein the constitution of the gas purifying apparatus is adapted to the purification of polluted air and equipped with a membrane module 12 having a large number of polypropylene hollow yarn membranes as gas permeable membranes permitting the permeation of a gas component other than air constituting components. Further, the apparatus 10 is equipped with a liquid supply device consisting of a liquid inflow pipe 14, a liquid pump 15 and a liquid outflow pipe 16 and an air introducing device consisting of an air inflow pipe 18, an air outflow pipe 20 and a suction blower 22. A polluted gas component in air flowing outside the hollow yarn membranes permeates through the hollow yarn membranes selectively to be dissolved and diffused in the gas dissolving liquid flowing through the hollow parts of the hollow yarn membranes to purify air. This air cleaning apparatus can produce high purity gas by considering gas components other than air constituting components to impure gas components in crude gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas purification method, an air purification method and an apparatus therefor, and more particularly, to a method for producing a high-purity gas by purifying a crude gas containing an impurity gas component, and an air purification method. The present invention relates to a method for purifying air contaminated by gas components other than constituent components, particularly air contaminated at a low concentration by a contaminated gas component, and an apparatus therefor.

[0002]

2. Description of the Related Art A method for producing a chemical product utilizing a gas reaction,
With the progress of solid processing methods using gases, various gases have been used. Nowadays, the fine processing technology using gas has been remarkably advanced, and it is increasingly necessary to use a high-purity gas for fine processing. In addition, the demand for high-purity gas has greatly increased as compared with the conventional case. For example, in a semiconductor device manufacturing plant, high-purity nitrogen gas
It is widely used in applications such as carrier gas, seal gas, purge gas, and pressurized gas, and high-purity SiH ₄ gas is used as a material for forming a semiconductor layer required for a semiconductor device.
Conventionally, crude nitrogen gas is produced by cryogenic separation of air,
Then, the crude gas is purified by removing the impurity gas components in the crude nitrogen gas by an adsorption method using a molecular sieve or a gas-liquid contact absorption method with an absorbing liquid to obtain a high-purity nitrogen gas.

[0003] On the other hand, there is also a concern about the influence of polluted air containing a trace amount of pollutant gas components. That is, in a space that requires clean air, for example, in a clean room of a semiconductor device manufacturing factory, or in an exhibition space such as an art museum or a museum, contaminated air containing a trace amount of a pollutant gas component is corroded,
There is a problem in that undesired effects such as deterioration are exerted on products, exhibits and the like.

[0004] For example, in a clean room provided in a semiconductor device manufacturing factory, if air is contaminated by chemicals used in the clean room, not only the health problem for the operator in the clean room, but also the product quality of the semiconductor device. May be reduced. In art museums and museums, if the air in the exhibition space is contaminated, there is a risk that the deterioration of valuable exhibition items will significantly progress due to the contaminated air. Further, in an analysis room or the like that performs high-precision analysis, there is a problem that the sample is contaminated by air contamination by the reagent, and the analysis accuracy is reduced. Furthermore, when a high concentration of a chemical is locally used in a factory, air is contaminated by gas components evaporated or vaporized from the chemical, which poses a problem from the viewpoint of work environment conservation.

In the case of purifying the contaminated air as described above, the purifying method has conventionally been an adsorption method of adsorbing and removing the contaminated gas component with an adsorbent such as activated carbon, and a method of filtering the contaminated air by filtering the contaminated air with a filter. It is roughly classified into a filtration method for removing contaminated air and a washing method for introducing contaminated air into a washing tower and washing with washing water to remove contaminated gas components.

[0006]

However, the conventional gas purification method uses an adsorption method and an absorption method of a gas-liquid contact system, so that a large-sized apparatus is required, and the purification process and operation are complicated. Therefore, it is inconvenient to apply when a large variety of high-purity gases are required in small quantities, as is the case today.
Not economic.

[0007] Also, regarding the purification of air, the conventional adsorption method, filtration method and cleaning method have a large gas-liquid contact area per unit volume, so that the apparatus becomes large, or low concentration of pollutant gas components from polluted air. It is technically difficult to remove the water, and in the cleaning method, the droplets of the cleaning water scatter around and troublesome in cleaning up, so that the cleaning of the contaminated air, especially the contamination at the time of local air pollution. It was not suitable for air purification.

Accordingly, an object of the present invention is to provide a gas purification method for obtaining a high-purity gas by purifying a crude gas by a simple means, and a method for contaminating air, particularly air having a local low-concentration by a simple means. It is an object of the present invention to provide an air purification method capable of efficiently purifying air into high-purity air, and an apparatus therefor.

[0009]

Means for Solving the Problems The present inventors use a gas permeable membrane to transmit an impurity gas component in a crude gas and dissolve the transmitted impurity gas component in a gas-soluble liquid.
By diffusing, purifying by removing the impurity gas components from the crude gas, and transmitting the contaminated gas components in the contaminated air, dissolving and diffusing the permeated gas components in the gas-soluble liquid, With the idea of purifying contaminated air, the present inventors have completed the present invention through repeated experiments.

In order to achieve the above object, a gas purification method according to the present invention is directed to a method for purifying a crude gas containing an impurity gas component in a gas circulation region and a liquid circulation region provided on both sides of a gas permeable membrane. The characteristic feature is that the impurity gas component in the crude gas is passed through the gas permeable membrane and dissolved in the gas soluble liquid while the gas soluble liquid is circulated along the gas permeable membrane to purify the crude gas. And

In the method of the present invention, the crude gas refers to a gas containing an impurity gas component, and is a source gas from which the impurity gas component is removed to obtain a high-purity gas. The method of the present invention can be applied regardless of the type of the crude gas and the type and concentration of the impurity gas component contained in the crude gas, and more specifically, the conventional gas-liquid contact physical absorption process and the conventional reaction absorption process can be applied. Things can basically be applied to everything.
The gas-soluble liquid is a liquid having solubility for the impurity gas component contained in the crude gas. For example, when the impurity gas component is CO ₂ , an inorganic solution such as a NaOH solution, an NaOH aqueous solution, and an ammonia aqueous solution is used. An alkaline solution or aqueous solution, or an organic alkaline solution or aqueous solution such as a monoethanolamine or diethanolamine aqueous solution. In the case of CO, an aqueous ammonia solution of a copper salt can be used, and in the case of CH ₄ , benzene, toluene and the like can be used. Water can be applied as a gas-soluble liquid to most impurity gas components.
Details of the combination of the impurity gas component and the gas-soluble liquid in the crude gas are as shown in Tables 1 and 2, for example.

[Table 1]

[Table 2]

In addition, the method of the present invention can be applied as an alternative to the usual gas-liquid contact physical absorption process, for example, by using water (preferably pure water) as a gas-soluble liquid, and isopropyne alcohol (pure water) from the atmosphere. IPA) can be removed. As an alternative to the usual gas-liquid contact type reaction absorption process, for example, ethanolamine (MEA), diethanolamine (DEA) or N
Using an aOH aqueous solution, CO ₂ and H ₂ S can be removed from natural gas, hydrogen gas, synthesis gas and the like. Further, as a gas-soluble liquid, diethylene glycol (DE
G) or triethylene glycol (TEG) can be used to remove moisture from natural gas, hydrogen gas, synthesis gas, and the like. Also, an aqueous ammonia solution (copper solution) of cuprous salt (carbonate, formate, acetate) can be used as a gas-soluble liquid to remove CO from the crude gas. Further, by using water as a gas-soluble liquid, it is possible to remove a fluorine compound gas such as SiF ₄ and HF from a crude gas.

The gas-permeable membrane used in the method of the present invention is a membrane which selectively permeates pollutant gas components and is impermeable to liquid, and is a porous membrane made of synthetic resin, for example,
A film made of polyolefin such as polyethylene, polypropylene, polymethylpentene, a film made of fluororesin such as polytetrafluoroethylene, vinylidene fluoride (PVDF), a film made of polysulfone, and a film made of silicon rubber are preferably used. it can. As the shape of the gas permeable membrane, any shape such as a flat membrane shape, a spiral shape, and a hollow fiber shape is used.In particular, a hollow fiber is knitted in a slender shape, and a spiral wound shape of the hollow fiber has a pressure loss. It is suitably used because of its small size.

Preferably, the gas-soluble liquid is caused to flow along the gas permeable membrane in a countercurrent direction to the flow direction of the crude gas. As a result, the crude gas having a low impurity concentration due to the permeation of the impurity gas component is further passed through the gas permeable membrane to the gas-soluble liquid having a low solubility concentration of the impurity gas component, that is, a gas-soluble liquid immediately after introduction having a high solubility. The contact gas component can transfer the remaining impurity gas component in the crude gas to the gas-soluble liquid, so that a gas with higher purity can be obtained.

Preferably, the humidity of the purified gas obtained by flowing through the gas flow area is adjusted. This makes it possible to adjust the humidity of the purified gas whose humidity has increased due to the transfer of water vapor from the gas-soluble liquid to the purified gas to a predetermined humidity.
In the case of removing moisture from the gas, a method of treating the gas with an adsorbent that adsorbs moisture or a gas separation membrane that allows moisture to pass can be employed. If the impurity gas component is a harmful gas component, the dissolved impurity gas component in the gas-soluble liquid flowing through the liquid flow area is removed by activated carbon, ion exchange resin, reverse osmosis membrane, etc. It may be discharged as a soluble liquid waste liquid. Furthermore, the gas-soluble liquid from which the dissolved impurity gas component has been removed can be introduced again into the liquid circulation area, and the gas-soluble liquid can be circulated and used.

Further, by applying the method of the present invention, impurity gas is removed from exhaust gas containing a rare gas such as argon and helium which is used in a large amount in a semiconductor device manufacturing factory or the like, and is highly economical. Can be purified and reused.

In the air purification method according to the present invention, in the gas refining method according to the first aspect, the crude gas and the impurity gas component are respectively air and polluted by a gas component other than the air component. Air and gas-soluble liquid contaminated by gas components other than air constituent components in the air circulation region and the liquid circulation region respectively provided on both sides thereof through the gas permeable membrane. It is characterized in that the contaminated gas components in the contaminated air are transmitted through the gas permeable membrane and dissolved in the gas-soluble liquid to purify the air while flowing along the gas permeable membrane.

In the present invention, the air component refers to oxygen, nitrogen, inert gas, carbon dioxide gas, and water vapor that constitute air. The gas components other than the air component are mixed with air and other components. Refers to gas components. The gas components other than the air component include, for example, hydrochloric acid, acetic acid, isopropyl alcohol, and ammonia, and plastics such as amines, hydrocarbons, NO _x , SO _x , dibutyl phthalate, and dioctyl phthalate. Agents may be mentioned as examples.
The gas-soluble liquid used in the method of the present invention is not limited as long as it is a liquid capable of dissolving the contaminant gas component. For example, when the contaminant gas component is an acid gas such as a chlorine gas or a hydrochloric acid gas as the gas-soluble liquid. When water has a low concentration of a pollutant gas component, it is preferable to use pure water or an alkaline solution. Water is used in the case of an alkaline gas such as ammonia gas, and pure water or an acidic solution is preferably used in the case where the concentration of the pollutant gas component is low. When the contaminant gas component is an organic compound gas such as isopropyl alcohol vapor, water is used. When the contaminant gas component has a low concentration, pure water is preferably used. The temperature of the gas-soluble liquid may be lower than the use limit temperature of the gas-permeable membrane to be used, but is preferably a temperature at which the gas solubility becomes higher. In general, the lower the temperature of the liquid, the higher the gas solubility, at least 4
Keep below 0 ° C. If the pollutant gas component is reactive,
It is preferable to select a gas-soluble liquid that easily reacts with the pollutant gas component.

In the present air purification method, as a gas component other than the air component, carbon dioxide excessively contained in air is targeted. The air can be purified. The carbon dioxide excessively contained in air refers to carbon dioxide contained in air at a concentration equal to or higher than the concentration of carbon dioxide contained in ordinary air. The method can be used when the carbon dioxide in the air increases due to working in a closed room, for example, when an astronaut is working in a spacecraft and the carbon dioxide in the air in the spacecraft increases. It can be suitably applied.

The method of the present invention can be applied to purification of air contaminated by a pollutant gas component regardless of the type and concentration of the pollutant gas component. Preferably, the gas-soluble liquid is caused to flow along the gas permeable membrane in a countercurrent direction to the air flow direction. As a result, the air that has become a low-concentration contaminated state due to the permeation of the contaminant gas component is further passed through the gas permeable membrane and further into the gas-soluble liquid having a low dissolved concentration of the gas component, that is, a gas-soluble liquid immediately after introduction having a high solubility. Since the contaminant gas components remaining in the air can be transferred to the gas-soluble liquid upon contact, the air can be purified into highly clean air. Preferably, the humidity of the air flowing through the air flow area is adjusted. As a result, air whose humidity has decreased due to the transfer of water vapor in the air to the gas-soluble liquid through the gas permeable membrane, and air whose humidity has increased due to the transfer of water vapor from the gas-soluble liquid to the air, The humidity can be adjusted to a predetermined humidity.
In addition, when humidifying the air with low humidity, a method of spraying the air with pure water in the form of mist is used, and when removing moisture from air with too high humidity, moisture is adsorbed. For example, a method of treating with an adsorbent or a gas separation membrane permeable to moisture can be employed. Further, when the pH of the gas-soluble liquid flowing through the liquid flow area becomes acidic or alkaline, the pH is neutralized and discharged, and when the gas-soluble liquid contains organic carbon, Is biologically treated and discharged. Further, the dissolved gas component in the gas-soluble liquid flowing through the liquid flow area can be removed by activated carbon, an ion exchange resin, a reverse osmosis membrane, or the like, and then introduced again into the liquid flow area. As a result, the gas-soluble liquid can be recycled. Further, the air circulating in the air circulating region can be processed by various filters conventionally used for purifying air. As described above, after the air is previously purified by the method of the present invention, the air is further purified by the filter, so that the replacement period of the filter can be greatly extended.

The most suitable gas purifying apparatus for carrying out the gas purifying method according to the present invention is provided on both sides of the gas permeable membrane through which the impurity gas component in the crude gas passes and through the gas permeable membrane. It has a gas circulation area and a liquid circulation area, and allows the impurity gas component in the crude gas flowing through the gas circulation area along the gas permeable membrane to pass through the gas permeable membrane and circulates the liquid circulation area along the gas permeable membrane. Gas permeable membrane device for dissolving in a gas-soluble liquid to be dissolved, a crude gas introduction device for introducing a crude gas into the gas permeable membrane device, and a liquid supply device for supplying the gas-soluble liquid to the gas permeable membrane device And is characterized by having. The gas purification apparatus according to the present invention uses the same or different gas-soluble liquids to increase the purity of the purified gas or to remove each impurity gas component when there are a plurality of types of impurity gas components. May be connected in series, a plurality of gas purifiers may be connected in parallel in order to increase the amount of purified gas flowing out, and furthermore, a series of devices connected in series May be arranged in a plurality of rows in parallel.

In a preferred embodiment of the present invention, the gas permeable membrane device is connected to the gas permeable membrane via the gas permeable membrane,
By configuring the gas chamber and the liquid chamber configured as the air circulation area and the liquid circulation area, respectively, as a gas permeable membrane module having an integrated structure, miniaturization and downsizing can be realized. Also, in a further preferred embodiment,
The gas permeable membrane module includes a hollow fiber membrane formed of a gas permeable membrane, and a housing that accommodates the hollow fiber membrane by extending the hollow fiber membrane in a longitudinal direction, wherein a hollow chamber inside the hollow fiber membrane serves as a liquid chamber, The space between the housing and the housing is used as a gas chamber, and by using a hollow fiber membrane configured as a gas permeable membrane as the gas permeable membrane, the gas-liquid contact area per unit volume through the gas permeable membrane is increased. Can be reduced in size and size.

[0023] The gas purifying apparatus according to the present invention is characterized in claim 10.
13. The gas permeable membrane according to any one of items 1 to 12, wherein the gas permeable membrane is a gas permeable membrane that allows gas components other than air components to pass therethrough, and the gas permeable membrane device is provided in the air flowing through the air circulation region along the gas permeable membrane. A device that allows gas components other than the air constituent components to pass through the gas permeable membrane and dissolves them in the gas-soluble liquid flowing through the liquid flow area along the gas permeable membrane, and a gas introduction device that converts air into the gas permeable membrane device By adopting the apparatus introduced into the apparatus, an air purifying apparatus optimal for performing the air purifying method according to the present invention is realized.

[0024]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Example 1 This example is an example in which a gas purification device according to the present invention using a hollow fiber membrane module as a gas permeable membrane is applied to an air purification device. Therefore, by replacing the contaminated air with the crude gas, the clean air with the purified gas, and the hydrochloric acid gas component with the impurity gas component, the air purification device can be made a gas purification device. FIG. 1 is a flow sheet showing the configuration of the air purification device of the present embodiment, and FIG. 2 is a partially cutaway perspective view of a hollow fiber membrane module.

As shown in FIG. 1, an air purifying apparatus 10 of this embodiment includes a gas permeable membrane module 12 (hereinafter simply referred to as a membrane module 12) using a hollow fiber membrane as a gas permeable membrane, and a liquid supply device. As an apparatus, a liquid inflow pipe 14 and a liquid outflow pipe 16 are connected to a liquid inlet and an outlet of the membrane module 12, respectively, and allow a gas-soluble liquid (hereinafter simply referred to as a liquid) to flow into the membrane module 12 and then to flow out. And a liquid pump 15 provided in the liquid inlet pipe 14 for supplying liquid, and an air inlet and outlet of the membrane module 12 as an air introducing device, respectively, for introducing contaminated air, and then for cleaning air. It has an air inflow pipe 18 and an air outflow pipe 20 for letting out air, and a suction blower 22 connected to the air outflow pipe 20 and sucking air.

The membrane module 12, as shown in FIG.
A cylindrical housing 24, a first chamber 26 and a second chamber 28, each of which is defined by partitioning the housing 24 by a partition plate 30 at a substantially midpoint in the longitudinal direction of the housing 24,
One end 32 of the housing 24 (hereinafter, the first end 32
) And the other end 34 (hereinafter, referred to as a second end 34), the central portion of the housing 24 extends in the longitudinal direction, and the air distribution tube 36 and the air collection tube partitioned by the partition plate 30. 38, disposed around the air distribution pipe 36 and the air collection pipe 38,
A plurality of hollow fiber membranes 40 penetrating the partition plate 30 and extending between the first end 32 and the second end 34 are provided.

The air distribution pipe 36 and the air collection pipe 38 are respectively
A large number of through holes 42 are provided in the tube wall, and air is distributed into the first chamber 26 through the through holes 42 and air is collected from the second chamber 28. The partition plate 30 is a disk-shaped plate having a diameter slightly smaller than the inner diameter of the housing 24, and the air flowing out of the air distribution pipe 36 into the first chamber 26 sews between a number of hollow fiber membranes 40. And then flows from the first chamber 26 to the second chamber 28 via the gap 44 between the housing 24 and the partition plate 30 and again returns to the multiple hollow fiber membranes 4.
After flowing as if sewn during 0, it flows into the air collecting tube 38. The hollow fiber membrane 40 is a hollow fiber membrane made of a porous polypropylene film, having a film thickness of 30 μm, an effective pore diameter of 0.05 μm, and a porosity of 30%.
It extends between a liquid distribution chamber (not shown) provided at one of the ends 34 and a liquid collecting chamber (not shown) provided at the other end. In a system in which air and liquid flow in countercurrent, air is supplied from the air inlet nozzle 46 provided at the first end 32 and connected to the air inlet pipe 18 to the air distribution pipe 3.
6 through the air collecting pipe 38 and out of the air outlet nozzle 48 provided at the second end 34 and the air outlet pipe 20 connected thereto. On the other hand, the liquid
And flows into the hollow fiber membrane 40 from the liquid inlet nozzle 50 connected to the liquid inflow pipe 14 through the liquid distribution chamber,
Next, the liquid flows out from the liquid outlet nozzle 52 and the liquid outlet pipe 16 connected thereto through the liquid collecting chamber provided at the first end portion 32. In the present embodiment, the inside of the hollow fiber is defined as a liquid circulation region, and the outside of the hollow fiber is defined as an air circulation region. Further, instead of the above-described method in which air and liquid flow in countercurrent, a method in which air and liquid flow in parallel may be used.

A commercially available product may be used as the membrane module 12 having the above-described structure. For example, a hollow fiber membrane module having a trade name of Rikicel (registered trademark) Extraflow sold by Hoechst International Tokyo Co., Ltd. may be used. It can be suitably used.

Hereinafter, a method of using the present air purification device 10 will be described. For example, when purifying air contaminated with hydrochloric acid gas, water is used as the liquid, and when the concentration of contamination is low, pure water or a weakly alkaline aqueous solution is selected, and the liquid pump 15 is started to activate the liquid. From the liquid inflow pipe 14 into the air purification device 10 and out of the liquid outflow pipe 16.
At the same time, the suction blower 22 is activated, and the air contaminated with the hydrochloric acid gas is passed through the air inlet pipe 18 to the air purifier 10.
The hydrochloric acid gas component is permeated through the hollow fiber membrane and dissolved in the liquid to purify the contaminated air. The purified air is transferred to a predetermined place via the air outlet pipe 20.

EXPERIMENTAL EXAMPLE 1 In order to evaluate the method of the present invention, an experiment was conducted by fabricating an experimental device 60 as shown in FIG. 3, the components having the same functions as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. The experimental device 60
A hollow fiber membrane module (model name: Rikicel 2.5 inch) manufactured by Hoechst is used as the membrane module 12,
As shown in FIG. 3, a contaminated air generation chamber 62 for generating contaminated air and feeding the contaminated air to the membrane module 12 is provided.
Having. The contaminated air generating chamber 62 includes a chemical evaporating tank 64 for evaporating a gas component for air contamination, and a stirring fan 66 for stirring and mixing the evaporated gas component and the air introduced into the contaminated air generating chamber 62. I have. The liquid inflow pipe 14 and the air inflow pipe 18 are provided with flow meters 68 and 70 for measuring the flow rates of liquid and air, respectively. The liquid outflow pipe 16 has a conductivity meter 72 for measuring the electric conductivity and the total organic carbon (TOC) of the outflowing liquid, and a TO meter TO.
A C total 74 is provided.

In Experimental Example 1, ultrapure water was selected as the liquid, and air contaminated with hydrochloric acid gas was purified with ultrapure water. Ultrapure water was introduced into the membrane module 12 at a flow rate of 20 liter / hr, and the electric conductivity was measured by the electric conductivity meter 72. The result was 0.27 μS / cm (blank value). Next, hydrochloric acid having a concentration of 35% is put into the chemical evaporating tank 64 and evaporated, and air having hydrochloric acid gas as a contaminant gas component is sucked by the suction blower 22 and introduced into the membrane module 12 at a flow rate of 90 l / hr. At the time of the steady state, the electric conductivity was measured and found to be 12.5 μS / cm.

In Experimental Example 1, hydrochloric acid gas in the air was transferred to ultrapure water via the hollow fiber membrane of the membrane module 12 and dissolved therein.
As a result of diffusion, the electric conductivity of ultrapure water is 0.27 μS /
It can be concluded that the value increased from 12.5 μS / cm from cm (blank value).

Experimental Example 2 In Experimental Example 2, air contaminated with IPA was purified with ultrapure water under the same flow conditions as in Experimental Example 1, except that isopropyl alcohol (IPA) was used instead of hydrochloric acid. The blank value of the TOC value of the ultrapure water is 5.0 ppb, and the TOC value measured at the time of the steady state becomes 80 ppb.
It was larger than 00ppb. In Experimental Example 2, IP in air
As a result of the gas A being transferred to the ultrapure water via the hollow fiber membrane of the membrane module 12 and dissolved and diffused, it can be concluded that the TOC value of the ultrapure water has increased from 5.0 ppb (blank value) to 8000 ppb or more.

Experimental Example 3 In Experimental Example 3, air contaminated with acetic acid was purified with ultrapure water under the same flow conditions as in Experimental Example 1, except that acetic acid was used instead of hydrochloric acid. When the electric conductivity and the TOC value were measured at the time of the steady state, respectively, 12.
It was 1 μS / cm and 2480 ppb. In Experimental Example 3,
The acetic acid gas in the air migrates into the ultrapure water through the hollow fiber membrane of the membrane module 12 and dissolves and diffuses, and as a result, the electric conductivity of the ultrapure water changes from 0.27 μS / cm (blank value) to 12.1 μs.
It can be concluded that the TOC value increased from 5.0 Cppb (blank value) to 2480 Cppb.

Experimental Example 4 In Experimental Example 4, air contaminated with acetic acid was purified with ultrapure water under the same flow conditions as in Experimental Example 1 except that ammonia was used instead of hydrochloric acid. When the electric conductivity was measured at the time of the steady state, it was 81.8 μS / cm. In Experimental Example 4, the ammonia gas in the air migrated into the ultrapure water through the hollow fiber membrane of the membrane module 12 to be dissolved and diffused. As a result, the electric conductivity of the ultrapure water was 0.27 μS / cm.
(Blank value) to 81.8 μS / cm.

Experimental Example 5 In Experimental Example 5, as shown in FIG. 6, instead of the contaminated air generation chamber 62 shown in FIG. 3, an experimental apparatus 60 was used except that actual contaminated air was introduced from a clean room for analysis. Using an experimental apparatus 120 having the same configuration as above, an ultrapure water was used as a gas-soluble liquid, and an air purification experiment was performed as in Experimental Example 1 as follows. Normal-temperature contaminated air flows into the gas permeable membrane module 12 at an inflow rate of 15 liters / minute, while ultrapure water at a temperature of 25 ° C. as a gas-soluble liquid flows into the gas permeable membrane module 12 at a flow rate of 20 liters / hr. Supply,
The process of purifying the contaminated air was continuously performed. Experimental device 1
At the time when the operation state of the pump 20 becomes a steady state, purified air is passed through the absorption bottle containing 300 ml of ultrapure water at a flow rate of 3 liter / min from the air outflow pipe 6 for 6 hours. The remaining contaminated gas components in the purified air were absorbed.
Subsequently, the ultrapure water in the absorption bottle was analyzed to determine the concentration of the residual contaminant gas component in the gas. The analysis result is as shown in the column of purified air in Table 3. At the same time, the polluted air was extracted from the air inlet pipe 18 under the same conditions as the purified air to determine the gas concentration of the polluted gas component in the polluted air. there were. The organic gas was analyzed by gas chromatography mass spectrometry, and the ammonia gas was analyzed by ion chromatography.

[Table 3]

[0037]Experimental example 6 In Experimental Example 6, an experimental apparatus 60 shown in FIG.
Is the same as the experimental device 122 shown in FIG._Twoincluding
N_TwoFrom gas to CO_TwoIs removed by using an aqueous NaOH solution.
Purity N_TwoAn experiment to obtain gas was performed. N_TwoGas cylinder
99.9999% N introduced_TwoCO in gas_TwoMoth
CO from the cylinder_TwoInject gas and CO_TwoConcentration 42
9ppb CO_TwoContained N_TwoA gas was prepared and the prepared CO_Two
Contained N_TwoGas pressure 1kg / cm^Two5 liter / min inflow
The gas flowed into the gas permeable membrane module 12 in an amount. On the other hand, liquid
0.1 mol / L NaOH aqueous solution at 25 ° C
Gas permeable membrane module at a flow rate of 20 liter / hr
12 to supply CO_TwoContained N_TwoFrom gas to CO_TwoRemove
And high purity N _TwoAn experiment for continuously obtaining gas was performed. Figure
7, 71 is CO_TwoA flow meter that measures the flow rate of gas
You. When the operating state of the experimental device 122 becomes a steady state
Then, into an absorption bottle containing 300 ml of ultrapure water,
Purified N at a flow rate of 0.5 l / min from the air outlet pipe 20
_TwoPurify N in ultrapure water by passing gas for 0.5 hour._TwoIn gas
Residual CO_TwoGas was absorbed. Next, the ultra pure absorption bottle
Water is analyzed by TOC meter to measure IC (inorganic carbon) concentration.
When the concentration in the gas was determined, CO_TwoGas in gas
The concentration was 23.7 ppb. Therefore, CO_TwoGas
The removal rate was 94%.

Experimental Example 7 In Experimental Example 7, CO ₂ -containing N ₂ gas of Experimental Example 6 was replaced with CO ₂ by an experimental apparatus 124 shown in FIG. 8 having the same basic configuration as the experimental apparatus 122 shown in FIG. An experiment was carried out to obtain high-purity air by removing CO ₂ from a high-purity air containing water with an aqueous NaOH solution. The high-purity air used in this experiment was
The composition is as follows. Composition of oxygen / nitrogen Atmospheric composition CO <0.1 ppm CO ₂ <0.1 ppm CH ₄ <0.1 ppm NO _X <0.01 ppm SO ₂ <0.01 ppm H ₂ O (dew point) <−80 ° C.

High-purity air introduced from a high-purity air cylinder
To CO_TwoCO from gas cylinder_TwoGas is introduced and CO_Two
CO with a concentration of 462 ppb_TwoPrepared and prepared air containing
CO _TwoGas permeation at a flow rate of 5 l / min containing air
It was allowed to flow into the membrane module 12. On the other hand, 25
0.1 mol / liter NaOH aqueous solution at 20 ° C
To the gas permeable membrane module 12 at a flow rate of Torr / hr.
And CO_TwoCO from contained air_TwoRemove the high purity air
Were continuously obtained. Operational condition of the experimental device 124
When the state becomes steady, it exceeds 300 ml
0.5 liter from the air outlet pipe 20 to the absorption bottle containing pure water
Purified N at a rate of_TwoGas for 0.5 hour
Residual CO in purified air in ultrapure water_TwoGas was absorbed.
Subsequently, the ultrapure water in the absorption bottle is analyzed by a TOC analyzer to obtain an IC.
Measured (inorganic carbon) concentration and found concentration in gas
RO, CO_TwoThe concentration of the gas in the gas was 139 ppb.
Therefore, CO_TwoThe gas removal rate was 70%.

Experimental Examples 1 to 4 demonstrate that the pollutant gas components in the polluted air have been reliably transferred to the liquid.
Based on the results of Experimental Examples 1 to 4, the air purifying apparatus 10 according to the present invention and the air purifying method according to the present invention using the same are capable of allowing a contaminated gas component to pass through a gas permeable membrane and dissolving it in a gas-soluble liquid. It can be evaluated as being able to diffuse and purify air.

Experimental Example 5 is an actual purification experiment of contaminated air introduced from a clean room for analysis. As can be seen from the fact that the removal rate of each contaminated gas was 70% or more, the method of the present invention was carried out in the following manner. It can be evaluated as an extremely effective purification method. In Experimental Examples 6 and 7, the experimental device 122,
It shows that it is possible to 124 to remove the CO ₂ in the CO ₂ containing N ₂ 94%, respectively from the gas and CO ₂ containing air and 70% high removal rate with the obtained high-purity N ₂ gas and high purity air I have.

Embodiment 2 As shown in FIG. 4A, in order to prevent the membrane module 12 from being clogged, an air purifying device 80 of this embodiment is provided with a filter 82 and an air inlet pipe 18 of Embodiment 1. , Filter 8
In consideration of the pressure loss of the air in 2, a pushing blower 84 is provided instead of the suction blower 22.

Embodiment 3 In order to control the humidity of the air purified by the membrane module 12, the air purifying apparatus 90 of the present embodiment has, in addition to the structure of Embodiment 2, as shown in FIG. Humidity control device 9 for controlling the humidity of air by adsorption of water, membrane separation or air cooling
2 is provided in the air outlet pipe 20.

Embodiment 4 An air purifying apparatus 100 of this embodiment is an example in which ultrapure water is circulated and used. In addition to the structure of Embodiment 1, as shown in FIG. In a circulation path connecting the liquid outflow pipe 14 and the ultrapure water supply equipment 102, a circulation pump 104, a removing device 106 for removing dissolved gas components from the liquid, and ultrapure water for improving gas solubility. And a cooler 108 for cooling the air. The air side may have the same configuration as in the second or third embodiment. As the removing device 106,
An activated carbon adsorption device, an ion exchange device, an electric regeneration type ion exchange device, a separation membrane device, an electrodialysis device and the like can be used. Preferably, as the equipment 102 for supplying ultrapure water, an ultrapure water tank 102 is provided upstream of the circulation pump, and the ultrapure water tank 102 is supplied with ultrapure water.

Application Examples There are various ways of purifying contaminated air using the air purifying apparatus according to the present invention, for example, the air purifying apparatus 10. For example, as shown in FIG.
The air purifier 10 is installed outside of the room 1 and the clean air obtained by purifying the contaminated air by the air purifier 10 is returned to the room 1 again.
In the external circulation system for returning the air to the air purifier 10, the air purifier 10 is installed outside the room 110 as shown in FIG.
Room 11 after purifying by taking in external contaminated air
0 may be introduced. Also, as shown in FIG.
An internal circulation system in which the air purification device 10 is installed in the room 110 having the contamination source and the clean air obtained by purifying the contaminated air by the air purification device 10 is returned to the room 110 again may be used. Further, as shown in FIG. 5D, the air purification device 10 is installed in a room having a pollution source, and the purified air obtained by purifying the contaminated air by the air purification device 10 is supplied to another centralized air conditioning equipment 112. , And may be air-conditioned to return from the centralized air-conditioning facility 112 to the room 110.

[0046]

According to the structure of the method of the present invention, the crude gas containing the impurity gas component and the gas-soluble liquid are respectively supplied to the gas flow area and the liquid flow area provided on both sides of the gas permeable membrane. The impurity gas component is allowed to pass through the gas permeable membrane and dissolved in the gas-soluble liquid while flowing along the gas permeable membrane, thereby purifying the crude gas into a high-purity gas. Since the method of the present invention is a gas-liquid non-contact method, the process configuration is simple, the operation is simple, and the apparatus cost is low as compared with the conventional gas-liquid contact adsorption method and gas-liquid contact absorption method. . Therefore, it is most suitable as a method for producing a small-scale high-purity gas, and the gas purifying apparatus according to the present invention is easy to miniaturize.

When the method of the present invention is applied to air purification, contaminated air and gas-soluble liquid are respectively applied along the gas permeable membrane to the air circulation area and the liquid circulation area respectively provided on both sides of the gas permeable membrane. The air is purified by permeating the contaminated gas component through the gas permeable membrane and dissolving it in the gas-soluble liquid while circulating the gas. Thus, the present invention has the following advantages. (1) By increasing the area of the gas permeable membrane per unit volume, for example, by using a hollow fiber membrane module with a high packing density, the gas-liquid contact area between air and the gas-soluble liquid can be freely increased. Therefore, the size of the air purification device can be reduced. (2) Since it can be miniaturized, it is most suitable for local treatment of contaminated air. (3)
Even low-concentration polluted air, which was difficult to purify in the conventional method, can be purified into high-purity air by appropriately selecting a gas-soluble liquid. (4) Since the air and the gas-soluble liquid are brought into gas-liquid contact in a non-mixed state via the gas permeable membrane, there is no problem such as entrainment of air.
(5) Since the contaminated air is purified in a closed state, there is no problem such as scattering of gas-soluble liquid droplets. (6) Since no regeneration operation is required unlike the adsorption method, the operation is simple.
(7) Since the film is used, no fine particles are contained in the purified air.

[Brief description of the drawings]

FIG. 1 is a flow sheet showing a configuration of an air purifying apparatus of Examples 1, 2, 3, and 4.

FIG. 2 is a partially cutaway perspective view showing the configuration of a hollow fiber membrane module.

FIG. 3 is a flow sheet showing a configuration of an experimental apparatus of Experimental Examples 1, 2, 3, and 4.

FIG. 4 is a flow sheet showing a configuration of Examples 2 to 4.

FIG. 5 is a schematic flow sheet showing an application example of the air purification device of the first embodiment.

FIG. 6 is a flow sheet showing a configuration of an experimental apparatus of Experimental Example 5.

FIG. 7 is a flow sheet illustrating a configuration of an experimental apparatus of Experimental Example 6.

FIG. 8 is a flow sheet showing a configuration of an experimental device of Experimental Example 7.

[Explanation of symbols]

Reference Signs List 10 Air purification device of Embodiment 1 12 Gas permeable membrane module 14 Liquid inflow pipe 15 Liquid pump 16 Liquid outflow pipe 18 Air inflow pipe 20 Air outflow pipe 22 Suction blower 24 Housing 26 First chamber 28 Second chamber 30 Partition plate 32 1 end 34 second end 36 air distribution pipe 38 air collection pipe 40 hollow fiber membrane 42 through hole 44 gap 46 air inlet nozzle 48 air outlet nozzle 50 liquid inlet nozzle 52 liquid outlet nozzle 60 experimental device 62 contaminated air generation chamber 64 chemical evaporation Tank 66 Fan 68, 70 Flow meter 71 CO ₂ gas flow meter 72 Conductivity meter 74 TOC meter 80 Air purification device of the second embodiment 82 Filter 84 Push-in blower 90 Air purification device of the third embodiment 92 Humidity control device 100 Fourth embodiment Air purification device 102 Ultrapure water supply equipment, ultrapure water tank 104 Circulation pump 1 6 remover 108 condenser 110 Room 112 centralized air-conditioning apparatus 120 experimental apparatus of the experimental apparatus 124 Experimental Example 7 of the experimental apparatus 122 Experimental Example 6 of Experimental Example 5

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akiko Umeka 1-4-9 Kawagishi, Toda City, Saitama Prefecture Inside Organo Research Institute (72) Daisaku Yano 1-4-9 Kawagishi, Toda City, Saitama Prefecture Organo Research Institute

Claims (13)

[Claims] 1. A crude gas containing an impurity gas component and a gas-soluble liquid are allowed to flow along a gas permeable membrane through a gas permeable membrane and into a gas circulation area and a liquid circulation area respectively provided on both sides of the gas permeable membrane. A gas purification method characterized in that an impurity gas component in a crude gas is permeated through a gas permeable membrane and dissolved in a gas-soluble liquid to purify the crude gas. 2. The gas purification method according to claim 1, wherein the gas-soluble liquid is caused to flow along the gas permeable membrane in a countercurrent direction to the flow direction of the crude gas. 3. The gas purification method according to claim 1, wherein the humidity of the purified gas obtained by flowing through the gas flow area is adjusted. 4. The gas purification method according to claim 1, wherein an impurity gas component is removed from the gas-soluble liquid flowing through the liquid flow area. 5. The gas purification method according to claim 4, wherein the gas-soluble liquid from which the impurity gas components have been removed is introduced again into the liquid circulation region. 6. The gas purification method according to claim 1, wherein
The crude gas and the impurity gas component are air contaminated with a gas component other than the air component and an air pollutant gas component other than the air component, respectively, and are provided on both sides thereof via a gas permeable membrane. The air and the gas-soluble liquid contaminated by the gas components other than the air component are allowed to flow along the gas permeable membrane in the air circulation area and the liquid circulation area, respectively, and the contaminated gas components in the contaminated air are passed through the gas permeable membrane. An air purification method, characterized in that it is permeated and dissolved in a gas-soluble liquid to purify air. 7. The gas purification method according to claim 6, wherein the humidity of the air flowing through the gas flow area is adjusted. 8. One of claims 2, 4 and 5
Wherein the crude gas and the impurity gas component are air contaminated by a gas component other than the air component and an air-contaminated gas component other than the air component, respectively. Purification method. 9. The carbon dioxide excessively contained in the air,
The method for purifying air according to any one of claims 6 to 8, wherein the gas is a gas component other than the air component. 10. A gas permeable membrane through which an impurity gas component in a crude gas permeates, and a gas flow area and a liquid flow area provided on both sides of the gas permeable film via the gas permeable film. A gas permeable membrane device that allows the impurity gas component in the crude gas flowing through the gas flow area to pass through the gas permeable membrane and dissolves in the gas-soluble liquid flowing through the liquid flow area along the gas permeable membrane. A gas purification device comprising: a crude gas introduction device for introducing a crude gas into a gas permeable membrane device; and a liquid supply device for supplying a gas-soluble liquid to the gas permeable membrane device. 11. A gas permeable membrane device is connected to the gas permeable membrane via the gas permeable membrane to form an integral structure of a gas chamber and a liquid chamber respectively configured as an air circulation area and a liquid circulation area. The gas purification device according to claim 10, wherein the gas purification device is configured as a gas permeable membrane module. 12. A gas permeable membrane module, comprising: a hollow fiber membrane made of a gas permeable membrane; and a housing for accommodating the hollow fiber membrane extending in a longitudinal direction, wherein an inner hollow portion of the hollow fiber membrane serves as a liquid chamber. The gas purification apparatus according to claim 11, wherein the space between the hollow fiber membrane and the housing is configured as a gas chamber. 13. The gas purifying apparatus according to claim 10, wherein the gas permeable membrane is a gas permeable membrane through which a gas component other than an air component is permeable. Gas components other than air components in the air flowing through the air circulation region along the gas permeable film are transmitted through the gas permeable film and dissolved in the gas-soluble liquid flowing through the liquid circulation region along the gas permeable film. An air purification device, wherein the device and the gas introduction device are devices for introducing air into the gas permeable membrane device.