JP4234496B2 - Method and apparatus for regenerating activated carbon and air purification system incorporating the same - Google Patents

Description

【００２８】
表２は、本発明の再生方法による活性炭ロス率を表している。ここで、活性炭ロス率＝（新品活性炭重量−再生後活性炭重量）／（新品活性炭重量）×１００と定義する。
【表２】

【００２９】
【発明の効果】
以上詳細に説明した如く、本発明の活性炭再生方法・再生装置によれば、長期間にわたり活性炭の減量が少なく、安全で再生効率の高い再生運転ができ、かつ大気汚染の問題も解決される。それを備えた空気浄化システムでは活性炭フィルターが半永久的に使用でき、省資源とともに、活性炭フィルターの圧力損失を大幅に削減でき、省エネルギ効果が極めて大きいなど、その技術的効果には極めて顕著なものがある。
【図面の簡単な説明】
【図１】 本発明による活性炭再生装置の概略回路図。
【図２】 他の実施例による活性炭再生装置の概略回路図。
【図３】 他の実施例による活性炭再生装置の概略回路図。
【図４】 活性炭再生装置を含む空気浄化システムの概略回路図。
【図５】 大気圧過熱蒸気再生と温風再生との効果を比較したグラフ。
【符号の説明】
１０，３０，５０ 活性炭再生装置
１２ 過熱蒸気供給部
１４ 吸着剤設置部
１６ 排気処理部
１８ 蒸気発生器
２０ 過熱用ヒーター
２２，７４ 活性炭フィルター
２４ 温度センサー
２６ 脱着ガス分解ユニット
２８ ブロア
６０ 空気浄化システム
６２ 空調対象室
６３ 配管
６６ 排気ファン
６９ 除塵フィルター
７０ フィルターユニット
７２ 空気浄化装置
７６ 空調機[0001]
BACKGROUND OF THE INVENTION
Conventionally, indoor air pollution includes dust, microorganisms, inorganic gaseous pollutants (NOx, SOx, ozone) and the like. In recent years, pollution problems due to organic chemicals have emerged and have become social problems. Especially in new buildings and classrooms, indoor concentrations of volatile organic compounds (hereinafter abbreviated as VOC) and formaldehyde (hereinafter abbreviated as HCHO) are abnormally high. There are many cases that develop into sick building (sickness building) and sick school syndrome, and many research reports have been made on current situation surveys and countermeasures.
[0002]
To solve this problem, the Ministry of Health, Labor and Welfare announced indoor guidelines for 13 substances such as VOC and HCHO, and the Ministry of Land, Infrastructure, Transport and Tourism announced a partial display of chemical substance indoor concentrations in the performance display system for houses in 2001. Added in August, the Ministry of Education, Culture, Sports, Science and Technology sets the standard value of chemical substances in the “School Environmental Hygiene Standards” for school facilities. This has been implemented since April 2002.
In addition, the Building Standard Law and the law on ensuring a sanitary environment in buildings were revised in 2002, and indoor air chemical contamination such as HCHO is legally regulated.
The present invention relates to a method and apparatus for regenerating an activated carbon filter used in an air conditioning or ventilation system to reduce the concentration of the harmful gas, and an air purification system incorporating the same.
[0003]
[Prior art]
As a conventional method of regenerating an adsorbent that has passed through after its lifetime,
A Hot air regeneration (Patent No. 3395077)
B Joule heat regeneration C Regeneration with jet steam under atmospheric pressure (Japanese Patent Laid-Open No. 7-275636)
D Regeneration of high-temperature pressurized superheated steam at an activated carbon regeneration plant is known.
[0004]
The problem with these methods is that
(1) For warm air regeneration (usually 150 to 200 ° C.), it is effective for low-boiling substances such as toluene (boiling point 110 ° C. or less), but in the indoor air, aliphatic saturated hydrocarbon dodecane, hexadecane, There are also a large amount of high-boiling substances such as phthalates, and such adsorbents have low regeneration efficiency. As a result, the adsorption performance of activated carbon decreases after regeneration a plurality of times.
(2) In the case of warm air regeneration or Joule heat regeneration, directly adding heat to activated carbon, which is a combustible material, in an atmosphere where oxygen is present in the air is not only exhaustive due to oxidation of the activated carbon, but also has a safety problem. Yes, you can not drive with unmanned automatic. In the case of a large building facility, there are tens or hundreds of air conditioning systems, and it is practically difficult for a person to regenerate activated carbon while monitoring.
[0005]
(3) In the case of atmospheric pressure saturated steam regeneration, the treatment target is activated carbon that has adsorbed NOx and SOx, which is effective due to the low regeneration temperature and the re-adsorption of VOC in the drying process by exhausting from the room after regeneration. Does not become a reliable playback system.
(4) High-temperature superheated steam regeneration at an activated carbon regeneration plant is regeneration under pressure, and is not suitable for incorporation into an air conditioning system or the like. In addition, the activated carbon is reduced by 2 to 9% per regeneration. Moreover, it cannot be applied to an air conditioning system due to problems such as pressure resistance and heat resistance (regeneration temperature 800 to 1000 ° C.). The loss of activated carbon due to regeneration is as large as 2 to 9% per time, and costs are high.
[0006]
(5) There is an air pollution problem due to exhaust during regeneration.
(6) The conventional activated carbon filter for air conditioning is increased in thickness to reduce the frequency of regeneration, and the SV value {passing air volume (m ³ / h) / adsorbent filling part volume (m ³ )} is 30,000. Even if it is as low as about / h, the pressure loss is as large as about 400 Pa.
(7) Reproduction efficiency is low. In particular, after a plurality of regenerations, the adsorbent adsorption performance decreases.
(8) In the conventional regeneration method, the exhaust gas during regeneration is not decomposed, and there is a problem of air pollution due to high-concentration regeneration exhaust gas. As a result, the total reduction of harmful chemical substances is not achieved. Rather, it only discharges from the room to the outside (atmosphere).
[0007]
[Problems to be solved by the invention]
The main object of the present invention is to provide a method and an apparatus for regenerating the activated carbon that has adsorbed and ruptured harmful gas safely and efficiently without consuming the activated carbon.
Another object of the present invention is to provide an air purification system that regenerates activated carbon that has adsorbed and broken through harmful gases and is incorporated in the air purification device.
Still another object of the present invention is to decompose the desorbed gas in the exhaust gas during regeneration so as not to pollute the atmosphere.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned problem, in the first aspect of the present invention, there is provided a method for regenerating activated carbon that has adsorbed harmful gases, wherein superheated steam at atmospheric pressure is used, and superheated steam is applied to a portion where activated carbon is disposed. introduced by filled, complete regeneration of reproducing by jetting a normal reproduction to reproduce by injecting superheated steam 150 to 250 ° C. for low boiling point material, the superheated steam of 300 to 350 ° C. relative to higher boiling materials The activated carbon regeneration method in which the complete regeneration is performed once after the normal regeneration is performed several times is provided.
[0009]
[Action]
According to such a regeneration method, normal regeneration (first stage) with 150 to 250 ° C. superheated steam for low boiling point substances (boiling point 110 ° C. or less) and 300 to 350 ° C. for high boiling point substances (above boiling point 110 ° C.). Combining the two regeneration conditions of complete regeneration with the superheated steam (second stage), normal regeneration is performed several times, and then complete regeneration is performed once to regenerate the activated carbon that has passed through and reduce the adsorption performance. Can be prevented.
[0010]
In the second aspect, the present invention is an apparatus for regenerating activated carbon that has adsorbed harmful gases, and is maintained in a state of atmospheric pressure with a superheated steam supply section that heats harmful substances contained in the activated carbon to a boiling point or higher. It has an adsorbent installation part that can be fitted with an activated carbon filter, and an exhaust treatment part.
The superheated steam supply unit includes a heating heater and steam generator being adapted to inject the activated carbon by supplying superheated steam at atmospheric pressure to the activated carbon filter in the adsorbent installation part, the low-boiling substances On the other hand, both normal regeneration in which 150 to 250 ° C superheated steam is injected and regenerated and complete regeneration in which high boiling point material is regenerated by injecting 300 to 350 ° C superheated steam are possible,
A temperature sensor is provided downstream of the adsorbent installation unit, and a unit for decomposing desorbed gas separated from the activated carbon is provided in the exhaust treatment unit,
Activated carbon regeneration that injects superheated steam into activated carbon and directly introduces the regenerated superheated steam exhaust into the decomposition unit, decomposes the desorbed gas using the residual heat of the regenerated exhaust , and discharges it into the atmosphere. Providing equipment.
[0011]
In such an apparatus, superheated steam at atmospheric pressure is used to regenerate the activated carbon. By introducing superheated steam into the activated carbon, which is a combustible material, and filling it up, oxygen necessary for combustion can be shut off, and the activated carbon is hardly consumed and safety is ensured. Since the pressure of regeneration by superheated steam is almost the same as the atmospheric pressure, the apparatus does not need pressure resistance.
Since superheated steam is used, there is no adsorption of moisture to the adsorbent in the case of saturated steam regeneration, and there is no need for a drying step of the adsorbent after regeneration, and there is no resorption of contaminants in the adsorbent in the drying step.
[0012]
Water molecules (H ₂ O) in superheated steam have a larger energy for desorbing adsorbed materials than air molecules (N ₂ , O ₂ ) in warm air regeneration, and regeneration with superheated steam is more efficient than warm air regeneration at the same temperature. High regeneration efficiency can be obtained.
The regenerated superheated steam exhaust is directly introduced into the desorption gas decomposition unit to decompose the chemicals in the exhaust. 95% or more of noxious gas (VOC) is purified by decomposition treatment and then discharged into the atmosphere.
[0013]
Furthermore, according to the apparatus of the present invention, the following operational effects can be obtained.
(1) Hydrothermal reaction of superheated steam and low- and high-boiling two-stage regeneration, good regeneration efficiency, and adsorbent can be used semipermanently (2) Regeneration with superheated steam under atmospheric pressure It is not necessary and can be applied to air-conditioning systems. (3) Since oxygen supply is shut off by filling the system with superheated steam during regeneration, there is almost no weight loss due to exhaustion of activated carbon, and safe regeneration is possible (4). Since the desorbed gas in the exhaust gas during regeneration is released into the atmosphere after being decomposed, the atmosphere is hardly polluted. (5) When incorporated in an air conditioning system as an air purification device with a regeneration function, it can be operated at a high SV value. The amount of adsorbent used can be reduced to 1/3 to 1/15 of the conventional, saving resources and space. (6) When incorporated in an air conditioning system as an air purification device with a regeneration function, it is low pressure loss and energy saving. It is not necessary to add a booster fan, and it can be handled with the external static pressure of AHU.
[0014]
As a third aspect of the present invention, an air purification system having a mechanism for regenerating activated carbon that has adsorbed harmful gases, a fan or blower for attracting air from an air-conditioning target chamber, and a filter unit including a dust filter, An air purification part including an activated carbon regeneration mechanism, an air conditioner, and a pipe connecting them,
The activated carbon regeneration mechanism includes a superheated steam supply unit that heats harmful substances contained in the activated carbon above its boiling point, an adsorbent installation unit that is maintained at atmospheric pressure and can be fitted with an activated carbon filter, and an exhaust treatment unit. And
The superheated steam supply unit and a heating heater and steam generator being adapted to inject the activated carbon by supplying superheated steam at atmospheric pressure to the activated carbon filter in the adsorbent installation part, the low-boiling substances On the other hand, both normal regeneration in which 150 to 250 ° C superheated steam is injected and regenerated and complete regeneration in which high boiling point material is regenerated by injecting 300 to 350 ° C superheated steam are possible,
A temperature sensor is provided downstream of the adsorbent installation unit, and a unit for decomposing desorbed gas separated from the activated carbon is provided in the exhaust treatment unit,
Air purification that injects superheated steam into activated carbon and directly introduces the regenerated superheated steam exhaust into the decomposition unit, decomposes the desorbed gas using the residual heat of the regenerated exhaust , and discharges it into the atmosphere. Provide a system.
[0015]
According to such an air purification system, an air conditioning system including a VOC removal device with a regeneration function combined with an air purification device (activated carbon filter) is constructed. Steam for regeneration is in an overheated state, but because it is atmospheric pressure, it does not require a pressure vessel and can be applied to air conditioning systems.
[0016]
Since the activated carbon filter for removing VOC incorporated in the conventional air purification system has a short activated lifetime, the SV value is set low as 1 to 50,000 / h to avoid frequent replacement of the broken filter. . In that case, since the amount of activated carbon used is large, the pressure loss of the filter is as large as 400 Pa (when the SV value is 30,000 / h).
This activated carbon air purification system enables safe and effective regeneration even if the activated carbon filter breaks through, enabling an SV value of 150,000 / h, and the amount of adsorbent used is 1/15 ~ 1/3, saving space, resources, and cost. In addition, by reducing the amount of activated carbon used, low pressure loss of the filter is realized, and it becomes possible to operate with external static pressure of the air conditioner without adding a booster fan, thus saving energy and cost.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 represents an activated carbon regenerator according to a preferred embodiment of the present invention. By repeatedly using this regenerator while changing the temperature conditions, the first stage normal regeneration and the second stage complete regeneration can be performed on the activated carbon.
The regenerator 10 in FIG. 1 includes a superheated steam supply unit 12 for heating above the boiling point of harmful gas, an adsorbent installation unit 14 maintained at atmospheric pressure, and an exhaust treatment unit 16, each of which is a pipe. Connected with. The superheated steam supply unit 12 includes a steam generator 18 and a superheater heater 20 and is connected to the adsorbent installation unit 14 by piping. The adsorbent installation unit 14 is provided with an activated carbon filter 22 that has adsorbed and broken through harmful gas, and a temperature sensor 24 is provided downstream thereof. The exhaust processing unit 16 includes an open / close damper VD1, an open / close damper VD2, a desorption gas decomposition unit 26, an air intake 27, and a blower 28, and is connected by piping.
[0018]
In the regenerator 10 of FIG. 1, superheated steam is supplied from the superheated steam supply unit 12 to the adsorbent installation unit 14 maintained at atmospheric pressure, and the activated carbon filter 22 that adsorbs and breaks through harmful gas is regenerated, The desorption gas decomposition unit 26 of the exhaust processing unit 16 purifies harmful gas (VOC) in the exhaust gas, and then exhausts it to the atmosphere. The temperature sensor 24 detects the temperature of the adsorbent installation unit 14 and adjusts the output of the overheating heater 20 so that the regeneration temperature is maintained at the set temperature.
[0019]
The decomposition method by the desorption gas decomposition unit 26 includes a catalyst decomposition method and a plasma decomposition method, and both methods can be adopted. As the catalyst used in the catalytic decomposition method, platinum, palladium, base metals cobalt, chromium, manganese, vanadium oxide, titanium dioxide or the like can be used. The regenerated superheated steam exhaust is directly introduced into the desorption gas decomposition unit, and the residual heat from the regenerated exhaust can be effectively used to decompose the chemicals in the exhaust. In particular, when platinum is used as a catalyst in the desorption gas decomposition unit, an auxiliary heater (not shown) is provided between the open / close damper VD1 of the exhaust treatment unit 16 and the desorption gas decomposition unit 26 to maintain the reaction rate of the catalyst unit. Is provided. By operating the open / close dampers VD1 and VD2, the amount of air exhausted from the desorption gas decomposition unit 26 and the amount of air taken in from the air intake 27 is adjusted, the inlet temperature of the blower 28 is kept below the heat resistance temperature of the blower, and the activated carbon filter An appropriate amount of regenerated steam is secured according to the pressure loss of 22.
[0020]
FIG. 2 shows an activated carbon regenerator according to another embodiment of the present invention. This regenerator 30 is characterized in that a circulation line 32 is provided in an adsorbent installation section 34 maintained at atmospheric pressure. Have. The circulation line 32 includes a pipe 36, a blower 38, a superheater heater 40, and a temperature sensor 42. The circulation line 32 adsorbs harmful gas and breaks through the downstream side of the first temperature sensor 24 provided in the adsorbent installation part 34. Each is connected to the upstream side of the activated carbon filter 22 via a pipe 36.
The circulation line 32 is provided in the adsorbent installation unit 34 after circulating a part of the exhaust gas using the blower 38 and reheating the superheater 40 with the superheated steam supplied from the superheated steam supply unit 12. This is an example of a method used for regeneration of the activated carbon filter 22. This embodiment has an advantage that the energy required for overheating can be reduced as compared with the example of FIG.
[0021]
FIG. 3 shows an activated carbon regenerator according to still another embodiment of the present invention. This regenerator 50 is characterized in that a purge line 52 is provided in an adsorbent installation section 54 maintained at atmospheric pressure. Have The purge line 52 includes an air inlet 55, a pipe 56, and an open / close damper MV1, and is connected to the upstream side of the activated carbon filter 22 that has adsorbed and broke through harmful gas in the adsorbent installation section 54.
When the opening / closing damper MV1 is opened with the blower 28 in operation after the regeneration process is completed, purge air flows in and the activated carbon can be quickly cooled. In the case of the example of FIG. 2, the purge air intake 55 can be provided in the middle of the circulation line 32.
[0022]
FIG. 4 shows an embodiment of an air purification system incorporating the above-described activated carbon regenerator. This air purification system 60 has a built-in air conditioning target room 62, piping 63 connecting each device, an outlet 64 for taking out RA (return air) from the air conditioning target room 62, an exhaust fan 66, and a dust removal filter 69. SA (supply air) is supplied to a filter unit 70 for introducing outside air from an inlet 68, an air purification device 72 including a rotary activated carbon filter 74 rotated by a motor 73, an air conditioner (AHU) 76, and an air conditioning target chamber 62. An air supply port 78 is included.
[0023]
The rotary activated carbon filter 74 is of the type described in the above-mentioned JP-A-7-275636, and has a function of regenerating while rotating the filter portion. During normal air conditioning, the open / close damper MV1 of the cooling air intake 75 is closed. At the time of regeneration, regeneration superheated steam from the steam generator 18 and the superheater heater 20 is introduced, and at the same time, cooling air is introduced from the cooling air intake 75 through the open / close damper MV1.
[0024]
In the air conditioning target room 62, during normal air conditioning operation, room air is taken out from the RA outlet 64, and a part of the air is exhausted by the exhaust fan 66. The remaining air and the outside air taken in from the outside air inlet 68 are removed by a dust removing filter 69 installed in the filter unit 70, and harmful gases are adsorbed and removed by a rotary activated carbon filter 74 installed in an air purification device 72. Then, clean air is sent to the air conditioner 76. A desired air condition (temperature / humidity) is obtained by the air conditioner 76 and air is supplied from the SA air supply port 78 to the air-conditioning target room 62.
[0025]
The activated carbon filter 74 rotates in the order of the adsorbing part → the desorbing part → the cooling part. At this time, the VOC concentration monitor 80 samples air from the upstream side and the downstream side of the rotary activated carbon filter 74 to determine whether the rotary activated carbon filter needs to be regenerated. The regeneration operation of the activated carbon filter 74 is performed during normal air conditioning operation or when air conditioning is stopped. The regeneration operation is performed by rotating the activated carbon filter 74 in the order of the desorption part, the cooling part, and the adsorption part. In the case of intermittent air conditioning, the regeneration operation may be performed when the air conditioning operation is stopped.
In this embodiment, the rotary activated carbon filter 74 is used, but a stationary activated carbon filter can also be used.
[0026]
FIG. 5 shows an effect comparison between atmospheric superheated steam regeneration and warm air regeneration according to the present invention. It has been proved that the regeneration method according to the present invention has much higher regeneration efficiency than the conventional warm air regeneration.
[0027]
Table 1 shows the results of comparing the present invention with a conventional activated carbon filter using the same honeycomb-shaped activated carbon.
[Table 1]

[0028]
Table 2 shows the activated carbon loss rate by the regeneration method of the present invention. Here, the activated carbon loss rate = (new activated carbon weight−regenerated activated carbon weight) / (new activated carbon weight) × 100.
[Table 2]

[0029]
【The invention's effect】
As described above in detail, according to the activated carbon regeneration method / regenerator of the present invention, the amount of activated carbon is reduced over a long period of time, and a regeneration operation with high safety and regeneration efficiency can be performed, and the problem of air pollution can be solved. In the air purification system equipped with it, the activated carbon filter can be used semi-permanently, the pressure loss of the activated carbon filter can be greatly reduced along with resource saving, the energy saving effect is extremely large, and the technical effect is extremely remarkable There is.
[Brief description of the drawings]
FIG. 1 is a schematic circuit diagram of an activated carbon regenerator according to the present invention.
FIG. 2 is a schematic circuit diagram of an activated carbon regenerator according to another embodiment.
FIG. 3 is a schematic circuit diagram of an activated carbon regenerator according to another embodiment.
FIG. 4 is a schematic circuit diagram of an air purification system including an activated carbon regenerator.
FIG. 5 is a graph comparing the effects of atmospheric superheated steam regeneration and warm air regeneration.
[Explanation of symbols]
10, 30, 50 Activated carbon regenerator 12 Superheated steam supply unit 14 Adsorbent installation unit 16 Exhaust processing unit 18 Steam generator 20 Superheater heater 22, 74 Activated carbon filter 24 Temperature sensor 26 Desorbed gas decomposition unit 28 Blower 60 Air purification system 62 Air conditioning target chamber 63 Piping 66 Exhaust fan 69 Dust removal filter 70 Filter unit 72 Air purification device 76 Air conditioner

Claims (3)

A method for regenerating activated carbon that has adsorbed harmful gases,
Use superheated steam at atmospheric pressure, introduce superheated steam into the part where the activated carbon is placed, and fill it,
Normal regeneration in which superheated steam at 150 to 250 ° C. is injected into the low boiling point material for regeneration ;
A combination of two regeneration conditions, ie, complete regeneration in which superheated steam at 300 to 350 ° C. is injected to a high-boiling point substance, and normal regeneration is performed several times and then complete regeneration is performed once. Activated carbon regeneration method. A device for regenerating activated carbon that has adsorbed harmful gases,
A superheated steam supply section that heats harmful substances contained in the activated carbon above its boiling point;
An adsorbent installation part that can be fitted with an activated carbon filter that is maintained at atmospheric pressure,
An exhaust treatment unit,
The superheated steam supply unit includes a heating heater and steam generator being adapted to inject the activated carbon by supplying superheated steam at atmospheric pressure to the activated carbon filter in the adsorbent installation part, the low-boiling substances On the other hand, both normal regeneration in which 150 to 250 ° C superheated steam is injected and regenerated and complete regeneration in which high boiling point material is regenerated by injecting 300 to 350 ° C superheated steam are possible,
A temperature sensor is provided downstream of the adsorbent installation part,
The exhaust treatment unit is provided with a unit for decomposing desorbed gas separated from the activated carbon,
Injecting superheated steam into activated carbon and introducing the regenerated superheated steam exhaust directly into the decomposition unit, and using the residual heat of the regenerated exhaust, decompose the desorbed gas and discharge it to the atmosphere. A featured activated carbon regenerator. An air purification system having a mechanism for regenerating activated carbon that has adsorbed harmful gases,
A fan or blower that attracts air from the air-conditioning target room, a filter unit that includes a dust removal filter, an air purification part that includes an activated carbon regeneration mechanism, an air conditioner, and a pipe that connects them,
The activated carbon regeneration mechanism includes a superheated steam supply unit that heats harmful substances contained in the activated carbon above its boiling point, an adsorbent installation unit that is maintained at atmospheric pressure and can be fitted with an activated carbon filter, and an exhaust treatment unit. And
The superheated steam supply unit and a heating heater and steam generator being adapted to inject the activated carbon by supplying superheated steam at atmospheric pressure to the activated carbon filter in the adsorbent installation part, the low-boiling substances On the other hand, both normal regeneration in which 150 to 250 ° C superheated steam is injected and regenerated and complete regeneration in which high boiling point material is regenerated by injecting 300 to 350 ° C superheated steam are possible,
A temperature sensor is provided downstream of the adsorbent installation part,
The exhaust treatment unit is provided with a unit for decomposing desorbed gas separated from the activated carbon,
Injecting superheated steam into activated carbon and introducing the regenerated superheated steam exhaust directly into the decomposition unit, and using the residual heat of the regenerated exhaust, decompose the desorbed gas and discharge it to the atmosphere. Features an air purification system.

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