JP2000140654A - Treatment of gas or water to be treated, and treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently adsorb and regenerate basic nitrogen compds. such as ammonia by supplying the objective gas to an adsorption layer having ion exchange fibers to adsorb harmful substances, supplying a desorption medium to the adsorption layer which stops adsorption so as to desorb the harmful substances, and then decomposing the desorbed harmful substances. SOLUTION: The objective gas is passed through a filter 3 to remove dust and supplied by a blower 6 through the gas supplying pipe 30 and an opening and closing valve 50 to an adsorption tank 2. Then the gas is passed through an adsorption layer 21 having ion exchange fibers in the adsorption tank 2 to adsorb the objective gas component to the adsorption layer 21. The treated gas is discharged through an upper opening part 22 and a three-way electromagnetic valve 29. After stopping the adsorption of the gas component on the adsorption layer 21, a desorption medium is supplied to the adsorption layer 21 to desorb the harmful substances. The desorbed harmful substances are cooled in a heat exchanger 9 with cooling water and then further cooled in a heat exchanger 10 with cold water to recover as a recovered liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for treating a gas or water to be treated. When the treatment method of the present invention is used, gas and water generated from industrial processes such as chemical factories and semiconductor factories, livestock production facilities, human waste treatment plants, and the like; or contained in water to be treated at water purification plants, water purification plants, and the like. Hazardous substances, typically, low-concentration basic nitrogen compounds such as ammonia and trimethylamine of several thousand ppm or less can be efficiently adsorbed and regenerated, so that harmful substances contained in the gas to be treated or the water to be treated can be reduced. Very useful for processing.

[0002]

2. Description of the Related Art Conventionally, the following methods have been employed for treating harmful substances contained in gas or water.

First, as a method of treating harmful substances contained in a gas, a method of treating a basic nitrogen oxide such as ammonia will be described as a typical example.

[0004] The treatment of basic gas containing nitrogen compounds such as ammonia and trimethylamine at a low concentration of several thousand ppm or less, which is generated from industrial processes such as chemical factories and semiconductor factories, livestock production facilities, human waste treatment plants, etc. Agency's report on the promotion of odor prevention technology improvement and promotion
November) is classified into several types, including a dry method and a wet method.

[0005] Among these, as the dry method, for example, an incinerator for direct combustion or the like is used. Also, Japanese Patent Application Laid-Open No. 6-633
No. 33 proposes a one-pass air purification system using an adsorbent such as ion exchange fiber. In addition, Japanese Utility Model Laid-Open No. 6-15725 discloses a deodorizing apparatus using a deodorizing filter in which a plurality of fiber materials having a deodorizing function are laminated. Further, Japanese Patent Application Laid-Open No. 2-59018 proposes an air purifier having an adsorption section containing activated carbon fibers and ion exchange fibers.

On the other hand, as the wet method, chemical cleaning by water cleaning or neutralization shown in FIG. 9 is used. Here, the gas to be treated is supplied from the lower part of the water washing tower by the blower 41, while the washing water is sent from the water storage layer 43 by the water supply pump 44 to the water circulation path circulated by the circulation pump 45, It is sprayed from a spray nozzle 46 provided at the top of the tower. The gas to be treated supplied from the lower portion of the washing tower is washed by the spray water and then separated into gas and mist by the mist separator 42. The gas is exhausted from the upper portion of the washing tower, while And water are discharged from the lower part of the washing tower, and a part of the water is recycled.

However, these methods have the following problems.

First, in the incinerator for direct combustion or the like in the dry method, the gas to be treated is oxidatively decomposed at a high temperature of 650 to 800 ° C., so that it consumes a lot of energy and emits nitrogen oxides (NOx) and greenhouses as combustion emissions. Effect gas (C
There is a problem that secondary pollutants such as O ₂ ) are generated.
In addition, in an exchange-type adsorption device that uses ion-exchange fiber as an adsorbent, the adsorbent is disposable, so it is necessary not only to replace the adsorbent frequently, but also to newly use the spent adsorbent. , Causing an increase in operating costs.

[0009] On the other hand, chemical cleaning by water cleaning or neutralization in the wet method has an advantage that the equipment cost is lower than other deodorizing techniques. However, the load on the wastewater treatment equipment is large in water cleaning, and the wastewater is reused. In such a case, the concentration of the gas component to be treated in the used cleaning liquid is low, so that regeneration costs are required separately.
Further, in the chemical cleaning, a post-treatment cost for the salt generated by the neutralization is newly required. Further, in order to maintain and manage complicated devices, daily management work such as inspection and calibration of instruments is inevitable, and equipment maintenance costs increase.

Next, as a method of treating harmful substances contained in water, a method of treating a basic nitrogen oxide such as ammonia will be described.

Conventionally, in order to remove ammonia contained in raw water taken from rivers and lakes, chlorination is generally used, or in an advanced water purification system, ozone treatment and biological activated carbon treatment are used in combination. I have.

However, in the case of chlorination, harmful chlorine compounds such as trihalomethane are produced as by-products, so that the amount of chlorine used is limited, and when the ammonia concentration is high, a sufficient removal rate cannot be obtained. I have a problem. On the other hand, instead of such chlorination, an advanced water purification system combining ozone treatment and biological activated carbon treatment is also widely used, but according to this system, ammonia is not mainly removed by the adsorption ability of activated carbon itself, It has been removed by biological nitrification treatment by microorganisms in the water (nitrifying bacteria) supplemented by activated carbon. The disadvantages of this biological treatment method are that the removal capacity at the initial start-up is insufficient, It has been pointed out that it is difficult to respond (Kubota Technical Report, No.2
3, P122-128, 1991).

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to efficiently remove harmful substances contained in a gas to be treated or water to be treated, particularly a basic nitrogen compound such as ammonia. A method capable of well performing adsorption regeneration treatment, specifically, when applied to gas treatment, consumes little energy and emits secondary pollutants such as nitrogen oxides (NOx) and greenhouse gases (CO ₂ ). It does not occur, does not require frequent replacement of the adsorbent, is inexpensive, and can be operated at low cost with simple daily management work and low equipment maintenance costs. In this case, it is possible to treat harmful substances, especially basic nitrogen compounds such as ammonia, without producing harmful chlorine compounds as a by-product. Even if it is used, it is necessary to provide a processing method that does not show the problems of biological processing methods (insufficient removal capacity at initial startup, difficulty in responding to rapid fluctuations in ammonia concentration, etc.); and a processing apparatus. is there.

[0014]

According to a first aspect of the present invention, there is provided a treatment method using an adsorption layer having ion-exchange fibers and supplying a gas or water to be treated to the adsorption layer. After the substance is adsorbed, a desorption medium is supplied to the adsorption layer where the adsorption is stopped to desorb the harmful substance, and the desorbed harmful substance is decomposed or recovered.

Further, in the second invention, a plurality of adsorption layers having ion exchange fibers are used, and a gas or water to be treated is switched and supplied to these adsorption layers to adsorb harmful substances, while the adsorption is stopped. An object of the present invention is to provide a method of supplying a desorption medium to an adsorption layer to desorb harmful substances and decompose or collect the desorbed harmful substances.

Here, it is a preferred embodiment of the present invention to use steam or a non-condensable gas as the desorption medium or to desorb harmful substances at a temperature of 80 to 200 ° C.

In the treatment method of the present invention, a method for treating a basic nitrogen compound contained in a gas to be treated or water to be treated by using a cation exchange fiber as an ion exchange fiber; A method for treating a carboxylic acid compound or an aldehyde compound contained in a gas to be treated or water to be treated by using an anion exchange fiber is included.

In particular, the treatment method of the present invention is effective for treating ammonia contained in a gas to be treated or water to be treated by using cation exchange fibers. In the ammonia treatment, air is mixed and oxidized. Ammonia is decomposed by contact with a catalyst, or the decomposition temperature is set to 200 to 40.
It is recommended to be 0 ° C.

Further, a processing apparatus for carrying out the first invention which can solve the above-mentioned problems includes an adsorption tank provided with an adsorption layer having ion exchange fibers, a harmful substance contained in a gas to be treated or water to be treated. A decomposition tank or a recovery tank for decomposing or recovering the gas, a supply means for supplying the gas or water to be treated to the adsorption layer, and a desorption means for supplying a desorption medium to the adsorption tank Medium supply means, and a desorption medium transfer means for transferring a desorption / exhaust medium to a decomposition tank or a recovery tank. The supply means for the gas to be treated or the water to be treated and the supply means for the desorption medium are switchable. It is provided.

Further, the treatment apparatus for carrying out the second invention comprises an adsorption tank provided with a plurality of adsorption layers having ion exchange fibers, a decomposition tank for decomposing or recovering harmful substances contained in the gas or water to be treated. A supply tank for supplying a gas or water to be treated to one adsorption layer of the adsorption layer, a supply means for supplying the gas or water to be treated, and a desorption medium to another adsorption layer of the adsorption layer A desorbing medium supply means for supplying the gas to be treated, a desorption / discharge medium transfer means for transferring the desorption / discharge medium to a decomposition tank or a recovery tank, and a supply means for the gas to be treated or water to be treated; Is provided to be switchable.

As the ion exchange fiber, both a cation exchange fiber and an anion exchange fiber can be used.
Among them, a cation exchange fiber is a fiber in which at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, and a sulfonic acid group is bonded to a fiber matrix; It is recommended to use one in which at least one functional group selected from the group consisting of an ammonium base and primary to tertiary amino groups is bonded to the fiber matrix. Further, the ion exchange fiber has a fineness of 1-1.
It is preferable to use a felt-like material having a denier of 0 denier, having a tensile strength of 0.5 kg / cm width or more and a breaking elongation of 100% or less.

[0022] The adsorption layer used in the present invention comprises a cylindrical cage shaped core having substantially the same diameter as the center hole fixed between a perforated flange having a center hole and a non-perforated flange. It is preferable that the felt-like material is wound in layers. Further, in the above processing apparatus,
Further, a heat exchanger for condensing a mixture of the desorbed component and the desorption medium desorbed from the adsorption tank and a tank for recovering the desorbed component condensed in the heat exchanger; Detecting means for detecting the temperature and humidity of the gas to be treated flowing in the adsorption tank, and controlling the temperature and humidity based on the detection result of the detecting means / detecting the temperature of the water to be treated flowing in the adsorption tank Detecting means, having a control means for controlling the temperature based on the detection result of the detecting means,
Both are preferred embodiments of the present invention.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors frequently exchange adsorbents for harmful substances contained in a gas to be treated or water to be treated, particularly basic nitrogen compounds represented by ammonia and the like, as in the prior art. In order to provide a novel adsorption / desorption regeneration treatment method which can be decomposed or recovered after being adsorbed and desorbed without any problem and with low energy consumption and low cost, intensive studies have been made. As a result, they found that the intended purpose can be achieved by using the adsorption layer having ion-exchange fibers and supplying the gas to be treated or the water to be treated to the adsorption layer and performing adsorption and desorption alternately. Completed the invention. In addition, when a plurality of adsorption layers having ion exchange fibers are used, for example, when one adsorption treatment is performed, the adsorption treatment is stopped and the desorption treatment is performed in the other adsorption layers, and the adsorption treatment is performed by alternately performing such treatment. Desorption can be carried out continuously and in large quantities, and a very useful invention can be obtained in practical use.

The use of the processing method and the processing apparatus of the present invention does not cause problems such as waste liquid processing in the conventional typical gas processing method, ie, the wet method, and eliminates the need for frequent replacement of the adsorbent. However, even if applied to the advanced water purification system consisting of ozone and biological activated carbon treatment, which is a typical conventional water treatment method, the problems of the biological treatment method (lack of removal capacity at initial startup, ammonia concentration This is extremely useful in that a continuous absorption / desorption regeneration processing system with low energy consumption and low cost can be established.

First, the processing method of the first invention will be described.

In the treatment method of the present invention, a gas to be treated or water to be treated is supplied to the adsorption layer using an adsorption layer having ion-exchange fibers to adsorb harmful substances, and then the adsorption is stopped. It is characterized in that a desorption medium is supplied to the layer to desorb harmful substances, and the desorbed harmful substances are decomposed or recovered.

For example, Japanese Patent Application Laid-Open No. 6-63 described in the prior art
No. 333 also discloses an air purification system using an ion exchange fiber adsorbent. This is a one-pass type air purification system, which is an air purification system that adsorbs ionic substances contained in air. Since there is no mention of detaching and recycling the filter, the air filter needs complicated replacement. In contrast,
The present invention differs from the above publication in that a desorption medium is supplied to the adsorbent to desorb harmful substances and the desorption tank is recycled.

In the second invention, the harmful adsorption and desorption are alternately performed by using such a plurality of adsorption layers and switching and supplying the gas to be treated or the water to be treated to these adsorption layers. There are two features. This eliminates the need for frequent replacement of the adsorbent as in the prior art, and has the advantage that the harmful substances contained in gas or water can be continuously adsorbed and desorbed and regenerated. Specifically, as described later, the supply means for the gas to be treated or the water to be treated and the supply means for the desorption medium are provided so as to be switchable. Therefore, when performing the adsorption treatment, the supply means for the desorption medium is stopped. Until the gas to be treated or the water to be treated is supplied;
By operating the desorption medium supply means while the supply means of the gas to be treated or the water to be treated is stopped, adsorption and desorption can be performed continuously and alternately, and the regeneration treatment can be performed efficiently. You can.

The shape of the adsorption layer used in the present invention is not particularly limited as long as it has ion exchange fibers.
For example, a box type, a column type, a cartridge type, and the like can be given, and an appropriate shape may be appropriately selected depending on the shape of the ion exchange fiber and the purpose of use. Among them, the use of a cartridge type is recommended. FIG. 3 is a schematic sectional view of the cartridge type adsorption layer, and FIG. 4 is a plan view cut along the line II of FIG. The adsorptive layer shown in FIG. 2 is fixed between a perforated flange 22 having a center hole and a non-perforated flange 23 and has a cylindrical cage-shaped core 24 having substantially the same diameter as the center hole. 26 has a hollow cylindrical structure in which the outer peripheral surface of the suction element 21 is fixed by a wire net 27. The adsorption layer may be fixed by a metal reinforcing material such as a punching metal or a wire, or a heat-resistant and chemical-resistant polymer.

The ion exchange fiber used in the present invention is a polyvinyl alcohol type, a polystyrene type, a phenol type,
Acrylonitrile-based fibers, woven fabrics, non-woven fabrics, and the like are subjected to a radiation graft polymerization method, a chemical treatment, or the like to impart ion exchange capability. Among them, the cation exchange fiber is a fiber in which at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, and a sulfone group is bonded to a fiber matrix; and the cation exchange fiber is a quaternary ammonium. Examples thereof include those in which at least one functional group selected from the group consisting of a base and primary to tertiary amino groups is bonded to a fiber matrix. These functional groups are preferably 2.
It is recommended that 0 mmol or more, more preferably 6.0 mmol or more be bound to the fiber matrix.

When cation exchange fibers are used,
Basic nitrogen compounds such as ammonia contained in the gas to be treated or water to be treated can be treated. On the other hand, if an anion exchange fiber is used, the carboxylic acid compound (acetic acid) contained in the gas to be treated or water to be treated can be treated. , Propionic acid, etc.) and aldehyde compounds (acetaldehyde, propionaldehyde, etc.).

The fineness of the ion exchange fiber is preferably 1 to 10 denier, more preferably 3 to 7 denier. If the fineness is smaller than 1 denier, the pressure loss after felt forming becomes large, and it is necessary to further increase the supply means capacity of the gas to be treated or the water to be treated. On the other hand, if the fineness is greater than 10 denier, the tensile strength after felt molding is reduced, and the felt may shift or sag during use, and gas or water may leak.

As the ion-exchange fiber, those processed into various shapes such as woven fabric, knitted fabric and non-woven fabric can be used. However, it is said that the contact area with gas can be widened and the ventilation resistance can be suppressed low. For this reason, those processed into a felt shape by a needle punch, a water punch or the like are preferably used. As described above, the treatment method of the present invention employs the adsorption / desorption method, and the adsorption layer is used repeatedly. However, if a felt-like material is used, the necessary strength and rigidity are secured, and the gas adsorption capacity is reduced. Can be suppressed.

Incidentally, in order to prevent the occurrence of gas leakage due to felt displacement and sagging in repeated use at low temperature and high humidity, and to obtain good adsorption characteristics and excellent workability,
It is important to control the tensile strength and elongation at break. In the present invention, the tensile strength of the felt-like material is 0.5
It is preferable that the width is not less than kg / cm width and the elongation at break is not more than 100%.

The above tensile strength and breaking elongation are measured as follows. Since the felt has directionality, the tensile strength and the elongation at break in the width direction and the length direction are measured. Specifically, 5 times each from the width direction and the length direction.
A test piece (width 25 mm, length 100 mm) of a book is cut out, and an Instron type tensile tester (for example, “STM-T-200BP” manufactured by Toyo Baldwin Co., Ltd.)
Then, the tensile strength at break and the elongation at break may be measured at a gripping distance of 50 mm and a tensile speed of 20 mm / min (elongation ratio of 40% / min).

In the present invention, in addition to the above-mentioned tensile strength and elongation at break, the basis weight of the felt-like material is 200 to 800.
g / m ² (more preferably 300~600g / m ^2), 1~8mm thickness (more preferably 2-4 mm) is recommended to.

The desorption medium used in the present invention is not particularly limited, but is preferably water vapor or a non-condensable gas. Among them, it is recommended to use superheated steam as the steam in order to uniformly desorb the gas component to be treated. It is also recommended to use heated, humidified nitrogen or air as the non-condensable gas. In addition, the combustion exhaust gas can be used as a desorption medium.

The temperature of the supplied desorption medium is 80 to
200 ° C. is preferred. However, when the desorption medium is steam, the pressure is more preferably set to 100 to 120 ° C. at 0.3 MPa or less. On the other hand, when the desorption medium is a non-condensable gas, the temperature is more preferably in the range of 120 to 150C. Further, it is generally recommended that the desorption processing time be about 3 to 30 minutes. As for the supply amount of the desorption medium, it is preferable to supply the desorption medium so that the desorbed gas component contained in the desorption gas discharged from the adsorption tank has a high concentration. From such a viewpoint, when the desorption medium is water vapor, it is preferable that the desorption medium be 50 times or less (more preferably, 5 times or less) the supply amount of the gas to be treated, while the desorption medium is a non-condensable gas. If the object to be treated is a gas,
1/5 or less of the supply amount of the gas to be treated (more preferably 1 /
50 times or less).

The harmful substances thus desorbed are decomposed or collected in a decomposition tank or a recovery tank. In order to condense the components (desorption components) of the gas to be treated contained in the desorption medium discharged from the adsorption tank, a heat exchanger is generally used. , 30 ° C. or lower (more preferably, 4 ° C. or lower). By controlling to such a low temperature, the concentration of the gas component to be treated in the initial stage of desorption that cannot be condensed by the heat exchanger can be reduced as much as possible, and can be returned to the upstream of the supply means of the gas to be treated or the water to be treated. In addition, it becomes possible to perform the process of recovering the gas component to be processed in a closed state.

The desorbed components condensed in the heat exchanger are recovered in the recovery tank. The concentration of the gas component to be treated in the recovered liquid and the concentrated gas is determined when the desorbed gas is treated under the aforementioned desorbed gas conditions. When the medium for use is steam, it is generally 2 to 17
%, And in the case of a non-condensable gas, approximately 5 to 50%.

The adsorption tank is provided with a temperature and humidity adjusting means for optimizing the temperature and humidity in the case of the gas to be treated, and a temperature adjusting means for optimizing the temperature of the water to be treated in the case of the water to be treated. Is preferred. The adjusting means includes a detecting means for detecting the temperature and the humidity or only the temperature, and a control means for controlling the temperature and the humidity based on the detection result of the detecting means. Of these, it is recommended that the detection means be installed upstream of the adsorption tank for the purpose of improving control responsiveness.
In this case, if the detection means is a basic gas, the detection means always comes into contact under high humidity, which may cause malfunction or early deterioration due to corrosion or the like. In order to prevent such inconvenience and maintain the reliability and safety of the detector, the detecting means may be installed on the downstream side of the adsorption tank.

Next, the processing apparatus according to the first invention will be described.

FIG. 1 is a schematic system diagram of a processing apparatus having an adsorption layer according to the first invention.

The treatment apparatus 1 has an adsorption tank 2, and the adsorption tank 2 has a hollow cylindrical structure in which a felt-like material made of ion-exchange fiber is wound around a cylindrical basket-shaped core in a layered manner. An adsorption layer 21 whose surface is fixed by a wire net is provided detachably. Note that the bottom of the adsorption layer 21 is closed. A discharge pipe 31 for the gas to be treated and a desorption medium supply pipe 32 connected to a desorption medium supply means are connected to the upper opening 22 of the adsorption layer 21 via a three-way solenoid valve 29a. A supply pipe 30 for the gas to be treated is connected to a side opening of the adsorption tank 2 via an on-off valve 50, and a desorption medium discharge pipe 33 is connected via an on-off valve 51.

First, the adsorption process will be described.

After the gas to be treated is removed by the filter 3, the gas is supplied from the on-off valve 50 to the adsorption tank 2 through the gas supply pipe 30 by the blower 6, and then passes through the adsorption layer 21 to be treated. The gas component is adsorbed by the adsorption layer 21, while the treated gas is discharged from the upper opening 22 through the three-way solenoid valve 29a. At this time, the on-off valve 51,
The three-way solenoid valve 29a on the side of the detachable medium supply pipe 32 and the on-off valve 40 on the drain line 41 are all closed.

At this time, the cooler 4 and the heater 5, which are temperature and humidity controllers, are controlled based on the value detected by the temperature and humidity detector 7 provided in the middle of the gas supply pipe 30 to be treated.
The temperature and humidity of the gas to be processed may be adjusted to a predetermined range.

Next, the desorption process will be described.

The desorption medium (for example, heated steam) supplied from the desorption medium supply means (not shown) passes through the desorption medium supply pipe 32, passes through the three-way solenoid valve 29a, and is connected to the adsorption tank 2.
Then, the gas passes through the opening 22 through the adsorption layer 21, and the gas component to be treated is desorbed from the adsorption layer 21 to regenerate the adsorption layer 21. And on-off valve 5
By leaving 1 open, the desorption medium containing the gas component to be treated passes through the desorption medium transfer pipe 33, is cooled by the cooling water heat exchanger 9, and then is passed through the pipe 35, and then the cold water heat exchange The mixture is further cooled in the vessel 10 and collected as a collection liquid. The collected liquid passes through the pipe 37 and is collected in the collection tank 1.
After being stored in the storage unit 1, it is sent to a processing device (not shown) such as a combustion processing device through a pipe 39 to be processed. At this time, the processing gas discharge pipe 31 side of the three-way solenoid valve 29a and the processing gas supply pipe 30 side of the on-off valve 50 are both closed.

Next, a processing apparatus using a plurality of adsorption layers according to the second invention will be described.

The treatment apparatus of the second invention comprises an adsorption tank provided with a plurality of adsorption layers having ion exchange fibers, and a decomposition tank or a recovery tank for decomposing or collecting harmful substances contained in the gas to be treated or the water to be treated. Supply means for supplying a gas to be treated or water to be treated to one adsorption layer of the adsorption layer, and a desorption medium for supplying a desorption medium to another adsorption layer of the adsorption layer Supply means, and a desorption medium transfer means for transferring the desorption medium to a decomposition tank or a recovery tank, wherein the supply means for the gas to be treated or the water to be treated and the desorption medium supply means are switchably provided. It has a gist where it is. The apparatus may further include a heat exchanger for condensing a mixture of the desorbed component and the desorption medium desorbed from the adsorption tank, and a tank for collecting the desorbed component condensed in the heat exchanger, The adsorption tank further includes a detection unit for detecting a temperature and a humidity of the gas to be processed flowing in the adsorption tank, and a control unit for controlling the temperature and the humidity based on the detection result of the detection unit / the adsorption tank. There may be provided a detecting means for detecting the temperature of the water to be treated flowing in the inside, and a controlling means for controlling the temperature based on the detection result of the detecting means, both of which are preferred embodiments of the present invention.

Hereinafter, a method for treating harmful substances contained in the gas to be treated or the water to be treated by using the treatment apparatus of the present invention will be described with reference to the drawings. In the following description, a method for treating harmful substances contained in the gas to be treated will be described for convenience. However, the same treatment is performed when water to be treated is used in place of the gas to be treated.

FIG. 2 is a schematic system diagram of the second invention processing apparatus. The treatment apparatus 1 has an adsorption tank 2, and the adsorption tank 2 has a hollow cylindrical structure in which a felt-like material made of ion-exchange fiber is wound around a cylindrical basket-shaped core in a layered manner, and its outer peripheral surface is a wire mesh. The adsorption layer 21 fixed by is provided detachably. Note that the bottom of the adsorption layer 21 is closed. The upper opening 22 of the adsorbing layer 21 is connected to a discharge pipe 31 for the gas to be treated and a desorption medium supply pipe 32 connected to the desorption medium supply means via three-way solenoid valves 29a and 29b. A three-way solenoid valve 28 is provided at the lower side opening of the adsorption tank 2.
The supply pipe 30 for the gas to be treated and the desorption medium discharge pipe 33 are connected via a and 28b.

For convenience of explanation, the adsorption layer provided on the left side of the adsorption tank 2 is used for adsorption processing, and the adsorption layer provided on the right side is used for desorption processing.

First, the adsorption process will be described. After the gas to be treated is removed of dust by the filter 3, it passes through the gas supply pipe 30 to be treated by the blower 6, and passes through the three-way solenoid valve 28 a
Is supplied to the adsorption tank 2 and then passes through the adsorption layer 21 so that the target gas component is adsorbed by the adsorption layer 21, while the processed gas is discharged from the upper opening 22 through the three-way solenoid valve 29 a. . At this time, the three-way solenoid valve 28a on the side of the detachable medium discharge pipe 33, the three-way solenoid valve 29a on the side of the detachable medium supply pipe 32, and the on-off valve 4 of the drain line 41
0 is in a closed state. At this time, the cooler 4 and the heater 5, which are temperature and humidity adjusters, are controlled based on the values detected by the temperature and humidity detector 7 provided in the middle of the gas supply pipe 30 so that the temperature and humidity of the gas to be processed are predetermined. The range may be adjusted.

Next, the desorption process will be described. The desorption medium (for example, heated steam) supplied from the desorption medium supply means (not shown) is supplied to the adsorption tank 2 through the desorption medium supply pipe 32 through the three-way solenoid valve 29b,
After passing through the adsorbing layer 21 through the opening 22, the adsorbing layer 2
The adsorption layer 21 is obtained by desorbing the gas component to be treated from 1
Is played. The desorption medium containing the gas component to be treated passes through the desorption medium discharge pipe 33 from the lower side opening of the adsorption tank 2 via the three-way solenoid valve 28b, is cooled by the cooling water heat exchanger 9, and is then cooled by the pipe 35. It is further cooled in the chilled water heat exchanger 10 that passes through and is recovered as a recovery liquid. This recovered liquid is stored in the recovery tank 11 through a pipe 37, and then sent to a processing device (not shown) such as a combustion processing device through a pipe 39 for processing. At this time, the three-way solenoid valve 29a and the three-way solenoid valve 2
The gas supply pipe 30 side 8a is closed.

The concentration of the gas component to be treated in the early stage of desorption that cannot be condensed by the heat exchanger is reduced as much as possible, and then returned to the upstream of the gas supply means through the pipe 38 to recover the gas component to be treated. Is performed under closed conditions.

The desorbed harmful substances are decomposed or collected in a decomposition tank or a recovery tank. For example, in decomposing ammonia, it is recommended to use a contact type decomposition tank filled with an oxidative decomposition catalyst and to mix air when transferring a desorption exhaust medium such as desorption exhaust gas to the decomposition tank. Also,
It is preferable to heat-exchange the desorbed ammonia-enriched gas and the gas for oxidative decomposition and the gas that has become hot after the oxidative decomposition using a heat exchanger to recover heat. The ammonia-enriched gas whose temperature has been raised is oxidatively decomposed in a decomposition tank and is processed into nitrogen and water. The decomposition temperature at this time is 200 to 400 ° C.
(More preferably 250 to 350 ° C.) is recommended.

The oxidative decomposition catalyst used in the first invention and the second invention is mainly composed of V ₂ O ₅ and WO ₃
An oxidation catalyst, such as supported on TiO _2, a honeycomb shape molded the _{V 2 O 5, WO 3 -TiO} 2 based oxidation catalysts are typically illustrated.

Although FIG. 2 shows a processing apparatus having two adsorbing layers, the number of adsorbing layers is not limited to two and may be a plurality of three or more. For example, in order to treat a gas to be treated using a treatment apparatus having three adsorption layers, one adsorption layer is used as an adsorption treatment layer, the other adsorption layer is used as a desorption treatment layer, and the remaining adsorption layer is used as a desorption treatment layer. The adsorption layer can be used as a reserve layer. The remaining adsorption layer is effective to smoothly switch between adsorption and desorption.Because there is a difference between the temperature suitable for adsorption and the temperature suitable for desorption, the switching from adsorption to desorption is smooth. As a preliminary layer before performing,
It can be applied to both the adsorption process and the desorption process.

The adsorption, desorption, and decomposition (or recovery) performed by the apparatus of the present invention have been described above. A series of these steps is schematically shown in FIG. In the figure, 61
Is a desorption layer, 62 is an adsorption layer, 63 is a gas blower, 64 is a heat exchanger, 65 is a gas heater, 66 is a decomposition tank, 67 is a gas to be treated, 68 is a purification gas, 69 is a desorption gas, 70 is a treated gas. , 71 are air.

The apparatus shown in FIGS. 1 and 2 is useful for treating harmful substances contained in gas, but can be applied to treatment of harmful substances contained in water. In FIG.
1 shows an example of a schematic process in which the treatment apparatus of the present invention is applied to water treatment.

FIG. 6 shows an example in which the apparatus of the present invention is applied to a conventional advanced water purification system comprising ozone treatment and biological activated carbon treatment. In the figure, the device of the present invention is used after the biological activated carbon. However, the present invention is not limited to this, and the device of the present invention may be used before ozone treatment or the like. It has been confirmed that substances, particularly a basic nitrogen compound represented by ammonia, can be efficiently removed.

According to the above embodiment, the removal of ammonia is efficiently performed by the apparatus of the present invention.
On the biological activated carbon side, it is mainly used to remove musty odors and trace organic substances including precursors such as trihalomethane, etc. This is extremely useful in that the shortage of ammonia removing ability does not cause a problem and the disadvantages of the biological treatment method can be overcome. Further, the ammonia adsorbed on the adsorption layer can be desorbed and decomposed (or recovered) thereafter, and the adsorption layer can be used repeatedly.

Hereinafter, the present invention will be described in detail based on embodiments. However, the following embodiments do not limit the present invention, and all modifications and alterations without departing from the spirit of the preceding and following embodiments are included in the technical scope of the present invention.

[0066]

EXAMPLES In the following examples, ion-exchange fibers were used.
Acrylic fibers are crosslinked with hydrazine to increase the nitrogen content, the remaining nitrile groups are eliminated by a hydrolysis reaction, and a carboxy group of 5.0 mmol / g and an amide group are introduced into the remaining (fineness: 3. 2 denier, tensile strength: 1.0 g / d or more) was used at 100% by weight, and processed into a felt shape by a needle punch method. The weight of the felt is 300 g / m ² ,
Thickness 2 mm, tensile strength 0.6 kg / cm width,
The elongation at that time is 100%, and the ventilation resistance at a passing linear velocity of 50 cm / s is 8 × 10 ⁻⁴ MPa. Such a felt-like material is layered around a cylindrical cage-shaped core having substantially the same diameter as the center hole fixed between a perforated flange having a center hole and a non-perforated flange, thereby forming a hollow cylinder. Layers, and the outer peripheral surface of the felt was fixed with a wire mesh and a wire.

The following Examples 1 to 4 and Comparative Examples 1 and 2
This is an example in which ammonia in the gas to be treated is treated.

Example 1 Using the processing apparatus shown in FIG. 2, a continuous adsorption test of ammonia gas was performed while changing the relative humidity, and the influence of the relative humidity on the adsorption treatment was examined. Specifically, the ammonia gas concentration is 500 ppm, the temperature is 25 ° C., and the relative humidity is 0R.
The gas to be treated, which was variously changed to H%, 65 RH%, and 100 RH%, was continuously supplied to the processing apparatus shown in FIG. 2, and the ammonia gas concentration at the gas outlet of the processing apparatus was measured.
The ammonia concentration was sampled in 1 L of Tedlar bag, and then the ammonia gas detection tube No. manufactured by Gastech Co., Ltd. was used. 3M, no. It was measured using 3H. FIG.
The results of these measurements are shown in a graph. In the figure, the vertical axis represents the ammonia concentration, and the horizontal axis represents the adsorption treatment time. It can be seen from the figure that when the relative humidity is 0 RH%, ammonia is hardly adsorbed, but as the humidity increases, the ammonia adsorption treatment efficiency increases and the breakthrough time increases. The ammonia concentration at the gas outlet is
Until the breakthrough time, it was 2 ppm or less, which was below the measurement lower limit of the detector tube, and it was confirmed that an advanced adsorption treatment with a removal rate of 99.6% or more could be realized.

Example 2 Using the same apparatus as in Example 1, the relationship between the properties of the desorption medium and the regeneration efficiency was investigated. First, ammonia concentration 2,
A gas to be treated having a concentration of 000 ppm, a temperature of 25 ° C. and a relative humidity of 65 RH% is supplied to the adsorption tank, and the component to be treated is adsorbed on the adsorption layer until the equilibrium adsorption amount is reached. Then, ammonia was desorbed from the adsorption layer, and the change of the ammonia concentration over time was measured with an ammonia gas detection tube No. manufactured by Gastech Co., Ltd. 3M, no. 3H
And the regeneration rate was calculated. Here, the regeneration rate was calculated by the following equation. Regeneration rate (%) = (desorption amount) / (equilibrium adsorption amount) × 100

The desorbing medium was 100 ° C.
Nitrogen at a relative humidity of 0% RH; air at a temperature of 100 ° C., 2% RH; and saturated steam at a temperature of 100 ° C. and 100% RH.
The type was used.

Table 1 shows the results.

[0072]

[Table 1]

As is clear from Table 1, when the adsorbed ammonia was regenerated with saturated steam, a high regeneration rate of 77% was obtained in a regeneration time of 30 minutes.

Example 3 Adsorption by continuous operation using the same processing apparatus as in Example 1
Playback processing was performed. As the gas to be treated, an ammonia gas concentration of 600 ppm, a temperature of 28 ° C., and a humidity of 83 to 88 RH%
Was supplied to the adsorption tank at a passing linear velocity of 30 cm / sec. 105 C, 0.3 M
Pa saturated steam was used as the desorption medium. Further, the ammonia-containing steam exhausted from the adsorption tank was condensed by a heat exchanger and then collected in a collection tank.

In the continuous operation of the gas treatment apparatus, when the adsorbing treatment is performed in one adsorbing layer, the other adsorbing layer is regenerated, and the remaining time is set to a standby state. The adsorbing time is 7 minutes, the regenerating time is 5 minutes, and the standby time is 2 minutes. The sequence was controlled so that adsorption and regeneration were alternately repeated.

Incidentally, the ammonia concentration at the inlet of the gas processing apparatus was measured by the ammonia gas detector tube No. manufactured by Gastech Co., Ltd. 3
The ammonia concentration at the outlet of the apparatus was continuously measured by a multi-gas monitor manufactured by Brüel & Kjær. FIG. 8 shows the change over time in the ammonia concentration at the apparatus outlet and the ammonia removal rate from the gas to be treated in the continuous operation.

From FIG. 8, in the continuous operation for 98 minutes,
The ammonia concentration at the outlet of the apparatus can be maintained at 2 ppm or less, and the ammonia removal rate from the gas to be treated is 99.
As high as 6% or more, it can be seen that ammonia can be effectively removed.

On the other hand, the ammonia concentration of the desorption gas discharged in the desorption step was about 2 vol%. From this,
It was confirmed that about 70% of the amount of ammonia adsorbed on the adsorption layer was desorbed by the regeneration treatment.

The desorbed gas was charged into a catalyst tower filled with a honeycomb catalyst to decompose ammonia. Specifically, air of substantially the same amount as the desorbed gas was mixed, the desorbed gas was heated to 250 ° C., and the reaction was performed in the catalyst tower under the conditions of a gas space velocity of 3000 hr ⁻¹ . As a result, the ammonia concentration of the outlet gas decreases to 9 ppm, and the by-product NOx
It was confirmed that the concentration could be suppressed to 15 ppm, and that ammonia could be efficiently rendered harmless.

Example 4 The performance of the gas treatment apparatus after continuous operation for about 6 months under the continuous operation conditions of Example 3 was examined by examining the ammonia concentration at the apparatus inlet, the ammonia concentration at the apparatus outlet, and the ammonia removal rate. . In addition, the ammonia removal rate was calculated by the following equation. Removal rate (%) = ｛1- (ammonia concentration at apparatus outlet) /
(Ammonia concentration at apparatus inlet)｝ × 100 The results are shown in Table 2.

[0081]

[Table 2]

As shown in Table 2, even after the continuous operation of the apparatus for 6 months, the ammonia concentration at the outlet of the apparatus was 2 ppm or less.
It can be seen that an excellent adsorption performance of 99.6% or more, which is the same as the result on the first day of continuous operation, can be obtained. Therefore, it was confirmed that stable operation of the apparatus was possible using the processing apparatus of the present invention.

Comparative Example 1 An adsorption treatment was performed using a conventional exchange-type gas treatment apparatus (using ion exchange fibers as an adsorbent) shown in FIG. This gas processing device will be described. First, filter 51
The gas to be treated from which dust has been removed is adjusted to a predetermined temperature and humidity by a temperature / humidity controller 52 based on the value detected by the temperature / humidity detector 54, and then supplied to the lower part of the gas processing apparatus, where the humidifier 53
Is further humidified and enters the adsorption filter 55. After the gas component to be processed is adsorbed and removed by the adsorption filter 55, the gas is exhausted from the processing apparatus by the blower 56. The adsorption treatment was performed under the same conditions as in Example 3 (ammonia gas concentration: 600 ppm, temperature: 28 ° C., humidity: 83 to 88R).
H%).

As a result, at the beginning of the treatment, the ammonia gas outlet concentration was 2 ppm or less, and the removal rate was 99.6% or more, indicating excellent adsorption performance. The ammonia concentration at the outlet gradually increased. As described above, when the exchange-type gas treatment apparatus shown in FIG. 10 is used, it is necessary to frequently change the adsorption filter in order to maintain good ammonia removal, and it takes a great deal of time and effort to exchange the adsorption filter. Was done.

Comparative Example 2 Using the conventional water washing tower shown in FIG. 9, adsorption treatment was performed under the same conditions as in Example 3 (ammonia gas concentration: 600 ppm, temperature: 28 ° C., humidity: 83 to 88 RH%). Specifically, the liquid /
Water washing was performed with a gas ratio of 1 to ³ L / m ³ .

As a result, the ammonia removal rate was about 90%, the ammonia concentration at the outlet of the apparatus was 60 ppm, and the ammonia removal rate was lower and the ammonia concentration at the outlet was higher than when the gas treatment apparatus of the present invention was used. The ammonia concentration in the recovered liquid after the washing was 0.01 to 0.04% by weight, which was only about one hundredth of the ammonia concentration of the desorption medium in the treatment apparatus of the present invention.

The following Example 5 and Comparative Example 3 are examples in which the ammonia contained in the water to be treated (raw water) in the water purification process was treated.

Example 5 A device was used in which a glass column was filled with 150 ml of the above-mentioned adsorption layer having felt-like ion-exchange fibers as a bulk volume, and ammonia was added to distilled water at a concentration of 1 mg / l. Raw water was passed at a flow rate of 50 ml / min. The ammonia concentration in the water after the treatment is below the detection limit (0.01
mg / l).

Comparative Example 4 The same treatment as in Example 5 was carried out except that the activated carbon was filled in a glass column. The ammonia concentration in the water after the treatment was 0.65 mg / l.

From the above results, it was found that when the device of the present invention was applied to water purification treatment, ammonia could be removed to a higher degree than when activated carbon was used. From this, the device of the present invention, when the biological treatment effect of the biological activated carbon treatment does not have a sufficient ability to remove ammonia,
That is, it is sufficiently suggested that a much higher ammonia removal efficiency is exhibited as compared with the case where ammonia is removed only by the adsorption ability of activated carbon. Therefore, when the device of the present invention is applied to the biological activated carbon treatment, ammonia can be efficiently removed by the device of the present invention. As a result, components other than ammonia are removed in the biological treatment, thereby shortening the initial startup time and reducing the ammonia concentration. It is possible to overcome the drawbacks of the biological treatment method because it is possible to achieve the prevention of slippage to the downstream final treatment step due to the fluctuation (rise) of the water.

[0091]

According to the present invention, a method capable of efficiently adsorbing and regenerating a harmful substance contained in a gas to be treated or water to be treated, particularly a basic nitrogen compound such as ammonia,
Specifically, when applied to gas processing, energy consumption is low, secondary pollutants such as nitrogen oxides (NOx) and greenhouse gases (CO ₂ ) are not generated, and the adsorbent is frequently replaced. It is not necessary to carry out the treatment, the treatment cost is low, the daily management work is easy, the equipment maintenance cost is low, and low-cost operation is possible. It is possible to treat harmful substances, especially basic nitrogen compounds such as ammonia, without producing it, and even if it is applied to an advanced water purification treatment system consisting of ozone and biological activated carbon treatment, there are problems with biological treatment methods It was possible to provide a processing method that does not show any points (insufficient removal capacity at initial start-up, difficulty in responding to rapid fluctuation of ammonia concentration, etc.).

[Brief description of the drawings]

FIG. 1 is a schematic system diagram of a processing apparatus for carrying out a first invention.

FIG. 2 is a schematic system diagram of a processing apparatus for carrying out the second invention.

FIG. 3 is a schematic sectional view of an adsorption layer used in the present invention.

FIG. 4 is a plan view cut along the line II of FIG. 3;

FIG. 5 is a schematic diagram showing processing steps performed by the apparatus of the present invention.

FIG. 6 is a schematic process diagram in which the treatment apparatus of the present invention is applied to water treatment.

FIG. 7 is a diagram showing a change in ammonia concentration at a gas outlet to be treated when a continuous adsorption process is performed in Example 1.

FIG. 8 is a graph showing a change over time in an ammonia concentration and an ammonia removal rate at a gas outlet to be treated by continuous operation in Example 3.

FIG. 9 is a side view of a conventional water cleaning device.

FIG. 10 is a side view of a conventional exchangeable gas processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas processing apparatus 2 Adsorption tank 4 Cooler 5 Heater 6 Blower 7 Target gas temperature / humidity detector 8 Desorption medium temperature / humidity detector 9 Cooling water heat exchanger 10 Cold water heat exchanger 11 Recovery liquid tank 21 Adsorption layer 22 Perforated Flange 23 Non-porous flange 24 Core 25 Round bar 26 Felt 27 Wire net 61 Desorption layer 62 Adsorption layer 63 Gas blower 64 Heat exchanger 65 Gas heater 66 Decomposition tank 67 Gas to be treated 68 Purified gas 69 Desorption gas 70 Treated gas 71 Air

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Manabu Asano 2-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Co., Ltd. (72) Inventor Tatsuaki Sumiya 2-8-2 Dojimahama, Kita-ku, Osaka-shi No. Toyobo Co., Ltd. Head Office (72) Inventor Shoichi Ibaraki 5-6-4 Tsukiji, Chuo-ku, Tokyo Inside Mitsui Engineering & Shipbuilding Co., Ltd. (72) Inventor Hirokuni Mihara 5- 6-4 Tsukiji, Chuo-ku, Tokyo Mitsui Engineering & Shipbuilding Co., Ltd. (72) Inventor Kazuki Tanita 3-3-3, Nakanoshima, Kita-ku, Osaka-shi, Osaka Mitsui Engineering & Shipbuilding Co., Ltd. Mitsui Engineering & Shipbuilding Co., Ltd.

Claims (16)

[Claims] 1. Use of an adsorption layer having ion exchange fibers,
A gas to be treated or water to be treated is supplied to the adsorption layer to adsorb harmful substances, a desorption medium is supplied to the adsorption layer in which the adsorption is stopped to desorb the harmful substances, and the desorbed harmful substances are removed. A method for treating a gas to be treated or water to be treated, which is decomposed or recovered. 2. A method of using a plurality of adsorption layers having ion-exchange fibers and supplying a gas to be treated or water to be treated to these adsorption layers to adsorb harmful substances, and a desorption medium to the adsorption layers where the adsorption is stopped. A method for treating a gas or water to be treated, wherein the desorbed harmful substance is decomposed or recovered by supplying harmful substances. 3. The processing method according to claim 1, wherein the desorption medium is water vapor or a non-condensable gas. 4. The processing method according to claim 1, wherein the harmful substance is desorbed at a temperature of 80 to 200 ° C. 5. Use of a cation exchange fiber as said ion exchange fiber to treat a basic nitrogen compound contained in a gas to be treated or water to be treated, or an anion exchange fiber as said ion exchange fiber The treatment method according to any one of claims 1 to 4, wherein a carboxylic acid compound or an aldehyde compound contained in the gas to be treated or the water to be treated is treated by using the compound. 6. The treatment method according to claim 5, wherein ammonia contained in a gas to be treated or water to be treated is treated by using the cation exchange fiber. 7. The treatment method according to claim 6, wherein ammonia is decomposed by mixing air and contacting with an oxidation catalyst. 8. The processing method according to claim 7, wherein the decomposition is performed at a temperature of 200 to 400 ° C. 9. An adsorption tank provided with an adsorption layer having ion exchange fibers, and a decomposition tank or a recovery tank for decomposing or collecting harmful substances contained in a gas to be treated or water to be treated, wherein the adsorption layer is subjected to treatment. Supply means for supplying gas or water to be treated to supply gas or water to be treated, desorption medium supply means for supplying a desorption medium to the adsorption tank, and desorption for transferring the desorption medium to a decomposition tank or a recovery tank A treatment medium transfer means, wherein the supply means of the gas to be treated or the water to be treated and the supply means of the desorption medium are switchably provided. 10. An adsorption tank provided with a plurality of adsorption layers having ion exchange fibers, and a decomposition tank or a recovery tank for decomposing or collecting harmful substances contained in a gas to be treated or water to be treated. Supply means for supplying a gas or water to be treated to the adsorption layer of the gas to be treated or water to be treated, desorption medium supply means for supplying a desorption medium to another adsorption layer of the adsorption layer, and desorption A desorption medium transfer means for transferring the medium to a decomposition tank or a recovery tank, wherein the supply means for the gas to be treated or the water to be treated and the supply means for the desorption medium are switchably provided. Characteristic processing device. 11. A cation-exchange fiber in which at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, and a sulfonic acid group is bonded to a fiber matrix; or a quaternary ammonium. The device according to claim 9 or 10, which is an anion exchange fiber obtained by bonding at least one functional group selected from the group consisting of a base and primary to tertiary amino groups to a fiber matrix. 12. The ion exchange fiber has a fineness of 1 to 1.
10. A felt material having a denier of 0 denier, wherein the tensile strength of the felt material is 0.5 kg / cm or more in width and the breaking elongation is 100% or less.
The apparatus according to any one of claims 1 to 11. 13. A felt made of ion-exchange fibers on a cylindrical cage-shaped core having substantially the same diameter as the center hole fixed between a perforated flange having a center hole and a non-perforated flange. The apparatus according to any one of claims 9 to 12, wherein the object is wound in layers. 14. A heat exchanger for condensing a mixture of a desorption component and a desorption medium desorbed from the adsorption tank, and a tank for recovering the desorption component condensed in the heat exchanger. Item 14. The apparatus according to any one of Items 9 to 13. 15. A detecting means for detecting the temperature and humidity of the gas to be processed flowing in the adsorbing tank, and a controlling means for controlling the temperature and humidity based on the detection result of the detecting means. The device according to any one of claims 9 to 14, which comprises: 16. The adsorption tank further comprises a detecting means for detecting the temperature of the water to be treated flowing in the adsorption tank, and a control means for controlling the temperature based on the detection result of the detecting means. An apparatus according to any one of claims 9 to 14.