JP2010022959A - Deodorization apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deodorization treatment apparatus not discharging a waste liquid of electrolytic water by re-utilizing the electrolytic water used for deodorization of VOC and outstandingly suppressing release of a chlorine gas from such a waste liquid. <P>SOLUTION: The deodorization apparatus is provided with a brine feeding part, an electrolytic water production part for producing acidic electrolytic water and alkaline electrolytic water by electrolyzing the brine, a deodorization part for performing deodorization treatment of a gas by contacting the acidic electrolytic water and the alkaline electrolytic water with the gas containing VOC sucked from the outside, an electrolytic water circulation route for feeding the electrolytic water to the deodorization part and circulating the electrolytic water used for the deodorization treatment to the electrolytic water production part, and a waste liquid regeneration part for regenerating the electrolytic water. The used electrolytic water circulated to the electrolytic water production part is re-electrolyzed in an electrolysis tank of the electrolytic water production part, and excessive used acidic electrolytic water and alkaline electrolytic water are mixed in a waste liquid mixing tank at the waste liquid regeneration part to perform neutralization. Thereafter, it is separated to concentrated brine and purified water by a reverse osmosis membrane, and the obtained concentrated brine and purified water are fed to the brine feeding part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a deodorizing apparatus that decomposes and removes volatile organic compounds (VOC), which are odorous components, and more particularly to a wet deodorizing apparatus that recycles and uses electrolyzed water once used. .

  VOC is an organic chemical substance that easily volatilizes in the atmosphere at normal temperature and pressure, and examples include odorous components such as toluene, benzene, chlorofluorocarbons, and dichloromethane. These VOCs are widely used in the industry as raw materials for cleaning agents, solvents, and fuels, but they are regarded as problematic because they can cause pollution and health damage when released into the atmosphere. ing. In Japan, VOCs have been regulated by the Air Pollution Control Act since 2004, assuming that VOCs are the main causes of photochemical oxidants and suspended particulate matter. In industrial facilities that handle VOCs, VOCs diffuse from the facilities into the air. There is an increasing demand to increase the removal rate.

Conventionally, strongly acidic and strongly alkaline electrolyzed water by a diaphragm electrolysis method has been used for deodorizing a low-concentration VOC or the like. In this type of deodorizing apparatus, deodorizing treatment is performed while measuring the pH of electrolyzed water (for example, Patent Document 1).
However, when a deodorizing treatment of a gas containing a high concentration of VOC is performed with such a deodorizing apparatus, various problems in performance occur. For example, conventionally, the electrolyzed water after the deodorizing treatment has been subjected to a neutralization treatment and discarded when a certain treatment is obtained, but it is preferable to discard a large amount of electrolyzed water from the viewpoints of economy and environment I could not say. In addition, the waste electrolyzed water contains chlorine gas, and it has been difficult to completely remove such chlorine gas only by the neutralization treatment.
JP 2006-212532 A

  The present invention has been made in view of the above circumstances, and by reusing the electrolyzed water used for VOC deodorization, the electrolyzed water was not discharged, and the release of chlorine gas from the waste was remarkably suppressed. An object is to provide a deodorizing apparatus.

In order to solve the above-mentioned problems, the present invention
A saline solution supply unit;
An electrolyzed water generating unit that electrolyzes the salt water supplied from the salt water supplying unit to generate acidic electrolyzed water and alkaline electrolyzed water;
A deodorizing unit that deodorizes the gas by bringing each of the acidic electrolyzed water and alkaline electrolyzed water into contact with a gas containing a volatile organic compound sucked from the outside, and
An electrolytic water circulation path for supplying the electrolytic water generated in the electrolytic water generation unit to the deodorization unit and circulating the electrolytic water used in the deodorization process in the deodorization unit to the electrolytic water generation unit;
A deodorization apparatus including a waste liquid regeneration unit for regenerating the electrolyzed water used in the deodorization unit,
The used electrolyzed water recirculated to the electrolyzed water generating unit through the electrolyzed water circulation path is re-electrolyzed in an electrolyzer of the electrolyzed water generating unit, and the used excess acid electrolyzed water and alkaline electrolyzed water are converted into the waste liquid regenerating unit. In the waste liquid mixing tank, neutralized and then separated into concentrated salt water and purified water by a reverse osmosis membrane, and the resulting concentrated salt water and purified water are supplied to the saline solution supply section Providing equipment.

  The saline solution supply unit is a device for supplying saline solution to the electrolyzed water generating unit. The saline solution supply unit includes a container for storing saline solution, a pipe connected to the electrolyzed water generation unit, and a pump.

Saline is a raw material for electrolyzed water. Examples of the electrolyte used for the saline include sodium chloride and sodium chloride, and sodium chloride is preferable from the viewpoints of cost, safety, and scale formation prevention.
The electrolyte concentration in the saline solution is not particularly limited as long as the pH strength in the desired electrolyzed water can be obtained. For example, an aqueous solution of 1 to 3% by weight of sodium chloride is preferable.
Moreover, you may use the chlorine-type electrolyte (for example, sodium chloride, potassium chloride, sodium bromide) which can remove | eliminate the VOC content odor instead of the said salt solution.

  In the electrolyzed water generating unit, the salt water is electrolyzed to generate acidic electrolyzed water and alkaline electrolyzed water. The electrolyzed water generating unit includes a DC power source, an anode, a cathode, and an electrolytic cell. The DC power source is connected to an anode electrode and a cathode electrode, and the anode and the cathode are arranged so as to be in contact with a saline solution filled in an electrolytic cell.

  It is preferable that the anode and the cathode of the electrolytic cell of the electrolyzed water generating unit are separated by a diaphragm. In an electrolytic cell separated by a diaphragm into a portion having an anode and a portion having a cathode, acidic electrolyzed water is generated at a portion where the anode is present, and alkaline electrolyzed water is generated at a portion where the cathode is present. Thus, VOC can be efficiently removed by using two types of electrolyzed water.

  In the deodorizing unit, each of the acidic electrolyzed water and alkaline electrolyzed water is brought into contact with a gas containing VOC sucked from the outside to deodorize the gas. The gas containing VOC is sucked from the outside and introduced into the deodorizing section through a pipe.

The deodorizing unit is preferably a multi-column scrubber capable of performing gas-liquid catalytic cracking and liquid-liquid catalytic cracking simultaneously.
Moreover, it is preferable that the deodorizing part into which acidic electrolyzed water is introduced and the deodorizing part into which alkaline electrolyzed water is introduced are arranged in series in the gas flow direction.

  From the deodorization part, deodorized gas and electrolyzed water containing VOC decomposition products are discharged.

  The electrolyzed water circulation path supplies the electrolyzed water generated in the electrolyzed water generating unit to the deodorizing unit and circulates the electrolyzed water used in the deodorizing process in the deodorizing unit to the electrolyzed water generating unit. The reflux of the electrolyzed water is performed using a pump. The used electrolyzed water recirculated to the electrolyzed water generating part by the electrolyzed water circulation path is re-electrolyzed in the electrolyzer of the electrolyzed water generating part.

  The waste liquid regeneration unit regenerates the electrolyzed water discharged from the deodorization unit. The waste liquid regeneration unit includes a waste liquid mixing tank, a pressure pump, and a reverse osmosis membrane.

  In the waste liquid mixing tank, acidic electrolyzed water and alkaline electrolyzed water are mixed and neutralized and stored. The pressurizing pump is used for filtering the electrolyzed water mixture with a reverse osmosis membrane. The electrolyzed water mixture is separated into concentrated salt water and purified water by the reverse osmosis membrane.

The reverse osmosis membrane is preferably a hollow fiber membrane, a spiral membrane or a tubular membrane.
Further, the material of the reverse osmosis membrane is preferably at least one selected from the group consisting of cellulose acetate, aromatic polyamide, polyvinyl alcohol and polysulfone.

  In the deodorizing apparatus of the present invention, used excess acidic electrolyzed water and alkaline electrolyzed water are separated into concentrated salt water and purified water by a reverse osmosis membrane in the waste liquid regeneration unit, and the obtained concentrated salt water and purified water are mixed with the salt solution. By supplying to the water supply unit, the used electrolyzed water can be reused without being discarded.

Further, the VOC to be treated according to the present invention may be any odorous component that can be perceived as a bad odor when the volatilization amount increases. For example, toluene, hexane, ethyl acetate, acetaldehyde, benzene, ethanol, styrene, acetic acid, Examples include xylene and methyl isobutyl ketone. In the present invention, ammonia and the like are also included in the VOC.
The VOC concentration in the gas before the deodorization treatment cannot be generally limited depending on the type of VOC. For example, in the case of ethyl acetate, a high concentration that can be felt as a bad odor, for example, a gas of about 600 to 800 ppm may be used. .

  The deodorizing apparatus of the present invention remarkably suppresses the consumption of electrolyzed water and leakage of chlorine gas from the electrolyzed water by regenerating and reusing the electrolyzed water used for the deodorizing treatment, as compared with the conventional deodorizing apparatus. be able to.

  The deodorizing part into which the acidic electrolyzed water is introduced and the deodorizing part into which the alkaline electrolyzed water is introduced are arranged in series in the gas flow direction, so that the odor effective for the acidic electrolyzed water and the alkaline electrolyzed water are effective. There is an advantage of removing odors at the same time.

  In addition, since the deodorizing part is a multi-column scrubber capable of performing gas-liquid catalytic cracking and liquid-liquid catalytic cracking simultaneously, there are advantages that it can deal with a wide range of odors and remove chlorine gas by introducing a rear alkali scrubber.

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic explanatory diagram of a deodorizing apparatus 1 of the present invention.
The deodorizing apparatus 1 includes a salt water supply unit 2, an electrolyzed water generation unit 3 that electrolyzes the salt water supplied from the salt water supply unit 2 to generate acidic electrolyzed water and alkaline electrolyzed water, and the acidic electrolyzed water. Each of the alkaline electrolyzed water and a gas containing VOC sucked from outside is brought into contact with the deodorizing unit 4 for deodorizing the gas, and the electrolyzed water generated by the electrolyzed water generating unit 3 is supplied to the deodorizing unit 4 In addition, the electrolyzed water circulation path (5a, 5b, 5a ′, 5b ′) for circulating the electrolyzed water used in the deodorizing process in the deodorizing unit 4 to the electrolyzed water generating unit 3, and the electrolyzed water used in the deodorizing unit 4 A waste liquid regenerating unit 6 for regenerating the liquid.

  The saline solution supply unit 2 includes a container 7 for storing saline solution, a pipe 8a for sending the saline solution to the electrolyzed water generating unit 3, and a pump 9a. The volume and shape of the container 7 may be appropriately determined based on the type of VOC, the volume of electrolyzed water necessary for processing the VOC, and the like.

  The pump 9a is used to send saline from the container 7 to the electrolytic cell 10 of the electrolyzed water generating unit 3 through the pipe 8a. The flow rate may be adjusted by the pump 9a, but a valve (not shown) may be provided in the piping as necessary.

  In the electrolyzed water generating unit 3 connected to the saline solution supplying unit 2 through the pipe 8a, acidic electrolyzed water and alkaline electrolyzed water are generated from the salt water by electrolysis. FIG. 2 shows an enlarged view of the electrolyzed water generating unit 3. The electrolyzed water generating unit 3 includes an electrolytic cell 10, a DC power source 11, a cathode 12 and an anode 13. The DC power source 11 is connected to the electrodes of the cathode 12 and the anode 13 by wiring. The cathode 12 and the anode 13 are disposed so as to be in contact with a saline solution filled in the electrolytic cell 10. The electrolytic cell 10 may be a resin casing that forms a flow path and ensures insulation. The types, materials, sizes, and the like of the DC power source 11, the cathode 12, and the anode 13 may be appropriately determined based on the type of VOC, the capacity of electrolytic water necessary for processing the VOC, and the like.

  In the electrolyzed water generating unit 3, the cathode 12 and the anode 13 of the electrolytic cell 10 are separated by a diaphragm 14. The diaphragm 14 may be any diaphragm used in electrolysis, and examples thereof include a film in which sodium ions can move to the cathode and chlorine ions to the anode, a neutral membrane, an ion exchange membrane, and the like. Absent. In the electrolytic cell 10 separated by the diaphragm 14 into a portion having the cathode 12 and a portion having the anode 13, alkaline electrolyzed water is generated at a portion where the cathode 12 is present, and acidic electrolyzed water is generated at a portion where the anode 13 is present.

  As shown in FIG. 1, the electrolytic cell 10 is connected to scrubbers (15 a, 15 b) constituting the deodorizing unit 4 through an electrolytic water circulation path (5 b, 5 c, 5 b ′, 5 c ′). Pumps (9b, 9c, 9b ′, 9c ′) for adjusting the flow rate of the electrolyzed water are provided in each pipe constituting the path, but a valve (not shown) is provided as necessary. Also good.

  The deodorizing unit 4 includes scrubbers 15a and 15b, and the electrolyzed water and a gas containing VOC are brought into contact with each other in the scrubbers 15a and 15b. For example, first, the gas containing VOC sucked from the outside is introduced into the inside from the lower part of the scrubber 15a constituting the deodorizing unit 4 through the pipe 8b, and simultaneously introduced into the upper part of the scrubber 15a through the pipe 8c. Water is sprayed from the nozzle 16a to perform contact processing.

Moreover, as shown in FIG. 1, it is preferable that the two types of scrubbers 15a and 15b are arranged in series with respect to the gas flow direction. The gas discharged from the upper part of the scrubber 15a is introduced into the lower part of the scrubber 15b through the pipe 8d, and at the same time, alkaline electrolyzed water introduced into the upper part of the scrubber 15b through the pipe 8e is sprayed from the nozzle 16b and comes into contact. Processing is performed.
In the deodorization part 4 which employ | adopted the above 2 types of scrubbers, since it can perform the deodorizing process of gas efficiently, since acidic electrolyzed water and alkaline electrolyzed water do not mix with each other, handle electrolyzed water efficiently. Can do. In addition, the order of treatment of acidic electrolyzed water and alkaline electrolyzed water is not particularly limited, and the electrolyzed water may be treated with alkaline electrolyzed water in the gas flow direction and then treated with acidic electrolyzed water.

  The scrubbers 15a and 15b constituting the deodorizing unit 4 are preferably multi-column scrubbers that can perform gas-liquid catalytic cracking and liquid-liquid catalytic cracking simultaneously. Gas-liquid catalytic cracking means that VOC is decomposed by contact with gas containing VOC and electrolyzed water. Liquid-liquid catalytic cracking means that VOC that is an oil layer component and electrolyzed water that is a water layer component are mixed. It means that VOC is decomposed by mixing contact. For example, in the scrubber 15a, the acidic electrolyzed water is introduced into the lowermost chamber 17a, and then the acidic electrolyzed water is sprayed from the nozzle 16a provided at the upper part of the scrubber through the pipe 8c by the pump 9d. The VOC is decomposed by being in gas-liquid contact with a gas containing VOC introduced from the above. The sprayed acidic electrolyzed water flows down into the chamber 17a provided at the lowermost part of the scrubber 15a and is mixed with the acidic electrolyzed water introduced from the electrolyzed water generating unit 3, but is partially liquefied also in the chamber 17a. The VOC and the electrolyzed water are brought into liquid-liquid contact to decompose the VOC. Similarly, in the scrubber 15b, alkaline electrolyzed water is sprayed from the nozzle 16b provided at the upper part of the scrubber by the pump 9e through the pipe 8e, so that the gas containing the VOC introduced from the lower part of the scrubber is brought into gas-liquid contact. The VOC is decomposed. The sprayed alkaline electrolyzed water flows down into the chamber 17b provided at the lowermost part of the scrubber 15b and is mixed with the alkaline electrolyzed water introduced from the electrolyzed water generating unit 3, but is partially liquefied also in the chamber 17b. The VOC and alkaline electrolyzed water are brought into liquid-liquid contact to decompose the VOC. The gas that has been subjected to the deodorizing process twice as described above is discharged to the outside from the upper part of the scrubber 15b through the pipe 8f. The pipe 8f may be provided with an adsorbent or the like as desired.

  When the deodorizing process is continuously performed with the scrubbers 15a and 15b, the VOC removal ability of acidic or alkaline electrolyzed water tends to decrease. In this case, new acidic or alkaline electrolyzed water may be supplied from the electrolyzed water generating unit 3 to the deodorizing unit 4 or the supply amount may be increased, but the electrolyzed water flowing down to the chambers 17a, 17b When the allowable amount is exceeded, the acidic electrolyzed water and alkaline electrolyzed water mixed with the VOC decomposition products are discharged from the chambers 17a and 17b to the waste liquid regeneration unit 6 through the pipes 8g and 8g 'as used surplus electrolytic water. Then, new electrolyzed water may be supplied.

The waste liquid regeneration unit 6 includes a waste liquid mixing tank 18, a pressure pump 19, and a filtration unit 20 including a reverse osmosis membrane.
As described above, the used surplus acidic electrolyzed water and alkaline electrolyzed water discharged from the pipes 8g and 8g ′ are introduced into the waste liquid mixing tank 18 and mixed. By mixing in this way, acidic electrolyzed water and alkaline electrolyzed water are neutralized. The waste liquid mixing tank 18 may be provided with a stirrer for quick mixing. In addition, what is necessary is just to determine a suitable capacity | capacitance and the structure of the said waste liquid mixing tank 18 based on the capacity | capacitance and kind of the electrolyzed water liquid mixture to process.
The mixed / neutralized electrolyzed water mixture is stored in the waste liquid mixing tank 18 until a predetermined amount is reached, and then the pressure pump 19 is operated to perform filtration with a reverse osmosis membrane via the pipe 8h. Part 20 is introduced.

  The pressurizing pump 19 only needs to be able to apply pressure to the electrolyzed water mixture so that the reverse osmosis membrane can separate the electrolyzed water mixture into concentrated salt water and purified water. The degree of pressurization depends on the performance of the reverse osmosis membrane. And it may be adjusted to an appropriate range depending on the type of electrolyzed water.

  As the reverse osmosis membrane, a reverse osmosis membrane includes a hollow fiber membrane, a spiral membrane, or a tubular membrane.

  The material of the reverse osmosis membrane may be at least one selected from the group consisting of cellulose acetate, aromatic polyamide, polyvinyl alcohol and polysulfone.

  Moreover, what is necessary is just to determine a suitable thing about the arrangement | positioning and structure of the reverse osmosis membrane in the said filtration part 20 based on the capacity | capacitance and kind of the electrolyzed water liquid mixture to process.

Concentrated salt water and purified water separated by a reverse osmosis membrane in the filtration unit 20 are supplied to the saline solution supply unit 2 through pipes 8i and 8j, respectively, and mixed with new saline solution in the container 7. .
In the present invention, as described above, there is an advantage that zero emission of waste water is possible by supplying the salt water supply unit 2 without mixing the concentrated salt water and purified water separated by the reverse osmosis membrane.

  As a material of each member which comprises the deodorizing apparatus 1 of this invention, what is necessary is just to be comprised with the material which is hard to receive the influence by VOC or salt solution.

  Moreover, although the gas deodorized by the deodorizing apparatus 1 of the present invention is released to the external environment through the pipe 8f, another process (for example, activated carbon adsorption, zeolite adsorption) may be performed.

As shown in FIG. 1, a saline solution supply unit 2 (a container capacity of 300 L, a supply amount of saline solution of 1 L / min),
Electrolyzed water generating unit 3 (current 100 to 200A, diaphragm: GS Yuasa filter),
Deodorizing section 4 (multi-column scrubber, capacity 5L) 2 towers,
Waste liquid regeneration unit 6 (capacity 300L of waste liquid mixing tank 18, reverse osmosis membrane: manufactured by Dow Film Tech, trade name SW series)
The deodorizing apparatus provided with was produced.

(Test Example 1)
In the deodorization apparatus obtained in Example 1, 1.5% by weight saline solution was used, and a deodorization of gas containing toluene, hexane, ethyl acetate, acetaldehyde, benzene, ethanol, styrene, acetic acid, xylene, ammonia, etc. as VOC As a result of the treatment, even with a gas containing 1200 ppm or more of VOC, the removal rate could be 55% or more and the residual chlorine gas could be suppressed to 1 ppm or less.
Moreover, although 1 L of salt water was supplied, the deodorization efficiency did not decrease even when the deodorization treatment was continued for 24 hours without discharging the excess electrolyzed water.

Schematic explanatory drawing which shows the embodiment of the deodorizing apparatus of this invention. The enlarged view of the electrolyzed water production | generation part of the deodorizing apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deodorization apparatus 2 Saline solution supply part 3 Electrolyzed water production | generation part 4 Deodorization part 5 Electrolyzed water circulation path 6 Waste liquid reproduction | regeneration part 7 Container 8 Piping 9 Pump 10 Electrolyzer 11 DC power supply 12 Cathode 13 Anode 14 Diaphragm 15 Scrubber 16 Nozzle 17 Chamber 18 Waste liquid Mixing tank 19 Pressure pump 20 Filtration unit with reverse osmosis membrane

Claims (5)

A saline solution supply unit;
An electrolyzed water generating unit that electrolyzes the salt water supplied from the salt water supplying unit to generate acidic electrolyzed water and alkaline electrolyzed water;
A deodorizing unit that deodorizes the gas by bringing each of the acidic electrolyzed water and alkaline electrolyzed water into contact with a gas containing a volatile organic compound sucked from the outside, and
An electrolytic water circulation path for supplying the electrolytic water generated in the electrolytic water generation unit to the deodorization unit and circulating the electrolytic water used in the deodorization process in the deodorization unit to the electrolytic water generation unit;
A deodorization apparatus including a waste liquid regeneration unit for regenerating the electrolyzed water used in the deodorization unit,
The used electrolyzed water recirculated to the electrolyzed water generating unit through the electrolyzed water circulation path is re-electrolyzed in an electrolyzer of the electrolyzed water generating unit, and the used excess acid electrolyzed water and alkaline electrolyzed water are converted into the waste liquid regenerating unit. In the waste liquid mixing tank, neutralized and then separated into concentrated salt water and purified water by a reverse osmosis membrane, and the resulting concentrated salt water and purified water are supplied to the saline solution supply section apparatus.   The deodorizing apparatus according to claim 1, wherein the reverse osmosis membrane is a hollow fiber membrane, a spiral membrane or a tubular membrane.   The deodorizing apparatus according to claim 1 or 2, wherein the material of the reverse osmosis membrane is at least one selected from the group consisting of cellulose acetate, aromatic polyamide, polyvinyl alcohol and polysulfone.   The deodorization apparatus in any one of Claims 1-3 by which the deodorizing part into which acidic electrolyzed water is introduced, and the deodorizing part into which alkaline electrolyzed water is introduced are arrange | positioned in series in the gas flow direction.   The deodorizing apparatus according to any one of claims 1 to 4, wherein the deodorizing unit is a multi-column scrubber capable of performing gas-liquid catalytic cracking and liquid-liquid catalytic cracking simultaneously.

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