KR200347129Y1 - Hot Air Desorption & Photo Catalistic Cleaning of VOC Type Desorber - Google Patents

Abstract

The present invention is an apparatus applied to a facility for desorption and regeneration of activated carbon in the activated carbon adsorption tower.

Adsorption towers (Fig. 1), which have been mainly used in the past, have been widely used as VOC removal facilities because of their simple structure and low equipment cost, but there is a problem that excessive activated carbon replacement cost is required due to the characteristics of activated carbon adsorption. Installation has solved the problem. The desorption method that has been generally used has been used to desorption and condensation by applying steam heat (Fig. 2), but the desorption device itself is expensive and the equipment cost is high due to the use of corrosion resistant materials by using steam. There was a need for a separate utility such as cooling water.

In recent years, the catalytic combustion system is applied, and the LNG combustion burner is attached to the catalytic combustion device as a heat source to desorb the high-temperature exhaust hot air discharged by heat-exchanged hot air and inject the VOC generated during the desorption into the catalytic combustion device again. After the combustion decomposition was discharged to the atmosphere (FIG. 4 method) was used.

However, this method has a problem that it is not suitable for use in a small capacity such as a desorption device because a separate fuel is required by using a burner combustion device using LNG as a clean fuel, and a complicated fuel supply line is required.

In order to solve this problem, a method of replacing a heat source with a heater suitable for a small capacity has been used (FIG. 5).

However, this method has a problem in that the inlet air heating is immediately performed in the case of burner heating, but the VOC is not decomposed to the atmosphere due to the low catalytic decomposition rate due to the delay of the heating time in the heater.

In some cases, the removal method of the desorbed VOC is removed by the biofilter, which is a biological treatment method, instead of the catalytic combustion method (FIG. 6 method). However, since the VOC is intermittently discharged as in this facility, it is necessary to separately supply microbial nutrients. In addition, the VOC emission concentration itself is very high as thousands of ppm, which is not suitable for decomposition into microorganisms, which makes it difficult to remove high efficiency and also has various problems such as waste water generation.

As mentioned above, various methods have been used or developed until now, but each method has big and small problems. Therefore, it is necessary to solve the problem and come up with the necessity of a method that is superior to the previous method in terms of economics.

Therefore, unlike other methods (Figures 2, 3, 4, 5, 6) currently developed or used as a desorption and regeneration device in activated carbon adsorption towers, there are few problems in use, and operation cost is low, and in terms of equipment cost, compared to combustion or biological methods. It has been devised to apply an inexpensive photocatalyst method.

Briefly, the present invention is a device that desorbs and regenerates the activated carbon in the adsorption tower. The hot air is blown into the activated carbon by a heater and a small fan to desorb the adsorbed VOC, and the desorbed VOC is decomposed while passing through a small capacity photocatalyst. It is a device to remove.

The photocatalytic device, which is a desorption device used in the present invention, is a device that uses the principle of oxidizing and reducing VOCs to carbon dioxide and water vapor by using holes and electrons generated on the surface of titanium dioxide when ultraviolet rays are irradiated onto the surface of titanium dioxide. The characteristic of oxidizing molecules by generating high energy corresponding to 30000K of thermal energy at room temperature has the advantage of simple device and low operating cost.

Referring to the operation method briefly described with reference to Figure 7 of the present invention, the operation of the desorption device during operation when the hot air generated by the air supply fan 10 and the heater 801 is blown into the adsorption tower (1) activated carbon 101 Is heated to desorb the VOC adsorbed on the activated carbon, and the desorbed VOC enters the photocatalyst 13 by the desorption hot fan 6 together with the air containing it and is irradiated with an ultraviolet lamp 1302 to activate On the surface of the honeycomb-shaped titanium dioxide coating plate 1301, it was configured to operate as a system that is decomposed and purified by carbon dioxide and water by photocatalytic reaction and then discharged into the atmosphere through the stack 3.

The effect of the present invention is to solve the problem of excessive activated carbon replacement cost by installing a separate desorption and regeneration device, and the effect of reducing the annual activated carbon replacement cost by tens of thousands of won can be obtained.

Secondly, the desorption and desorption by steam heat, a desorption and regeneration device that has been mainly used in the past, and the desorption VOC have a problem of excessive facility cost of cooling and condensation and a separate utility using a separate photocatalyst method. It is possible to obtain the effect of providing an economical detachable device without the need and low cost.

Thirdly, in the case of catalytic decomposition of VOC generated during desorption, the heating is delayed to 200 ° C or more necessary for catalytic decomposition due to the delay of heater heating, and thus, some of the desorbed VOC is not decomposed initially due to low catalytic decomposition efficiency. The photocatalyst, which had a problem of being discharged into the atmosphere, has a high-efficiency decomposition reaction directly in a titanium dioxide coating plate when only ultraviolet rays are irradiated. Thus, unlike catalytic combustion, high-efficiency removal can be achieved from the initial stage of desorption.

Fourthly, in the case of microbial method, if desorption is intermittent like this facility, VOC is intermittently discharged, and it needs to be supplied separately with microbial nutrients, and the VOC emission concentration itself is thousands of ppm, which is not suitable for decomposition into microorganisms. It is difficult to remove, and waste water is generated.

The present design has no problem at all, as compared with the microbial treatment method, the desorption efficiency is superior, and the operation is simple and the maintenance is convenient.

As a result, the present invention is effective in solving the problems of various conventional methods and at the same time, the process gas is simple and the desorption VOC purifier used in the photocatalytic method, direct combustion method, catalytic combustion method, biological treatment method, etc. The lowest cost per 1㎥ / minute, the equipment cost is not only significantly lower, but also in terms of operating costs, such as power costs, it is the method with excellent economic efficiency.

Description

Photocatalytic purification desorption device for hot air desorption and desorption of volatile organic vapors. {Hot Air Desorption & Photo Catalistic Cleaning of VOC Type Desorber}

Many facilities, such as painting, printing, and washing facilities, use high molecular organic compounds, and in the process, they contain large amounts of Volatile Organic Compounds (VOCs) such as toluene and xylene. Emissions in the air cause air pollution.

In order to prevent air pollution due to such VOC, various types of purification facilities are used, but most of them use activated carbon adsorption method.

Until now, VOC removal technology using activated carbon adsorption has been developed in order to improve the disadvantages of the methods used in the past, and a few of them will be described in detail. Before describing each method, briefly describe the basic technologies of the present method: activated carbon adsorption method, direct combustion method, catalytic combustion method and biological treatment method.

(1) Activated carbon adsorption method

Activated carbon has many micropores and large surface area. When VOCs with high molecular weight such as benzene, toluene and xylene gas pass through activated carbon layer, organic gas molecules are introduced into the micropores by van der Waals forces, and the pressure is very high in the micropores. It is easily supersaturated, so it is adsorbed on the surface of micropores in a condensed state. This adsorption characteristic means that the VOC is continuously adsorbed and has a limited characteristic that can not be adsorbed anymore. This means that the activated carbon introduced into the adsorption column is no longer able to remove the VOC when the activated carbon is saturated. It must be replaced or removed and reused.

The desorption process for desorption and reuse of activated carbon is performed by applying hot air or steam of 100 ° C. or higher because the activated carbon micropores are restored to their original state by the evaporation and desorption of VOC adsorbed on the surface of the activated carbon in the liquid phase.

(2) Direct combustion method

After introducing VOC-containing air into the combustion apparatus, it is heated and burned with LNG combustion heat to burn and oxidize the combustion at a high temperature of 600 to 800 ° C.

This method has to be heated to a high temperature, so there is a problem in that the fuel cost is high and nitrogen oxides are generated by the flame, but it is somewhat inexpensive than the catalytic decomposition method and is used when the catalytic poisoning method is difficult because the catalyst poison is discharged together.

(3) catalytic combustion method

The catalyst is made of platinum, palladium, etc. It does not participate directly in the reaction itself, but lowers the activation energy of the reactants to promote the reaction to burn at 150 ~ 250 ℃ much lower than the combustion oxidation temperature of VOC 600 ~ 800 ℃ It is a substance that enables oxidation and saves energy. The catalytic combustion method is a method of using such a catalyst to raise the temperature to 150 ~ 250 ℃ capable of combustion decomposition through the catalyst bed to remove the combustion decomposition by the reaction scheme as follows.

As shown in the above reaction, when decomposing VOC in the catalyst layer, the gas temperature is increased by self-heating oxidation and the degree of increase is proportional to the VOC concentration.If the catalyst bed inlet temperature is 200 ℃ and the VOC concentration is about 1000ppm, the hot air temperature after catalytic decomposition is about 300 ℃. To rise. This is because VOC self-decomposition heat passes through the catalyst bed, and the gas temperature rises, resulting in higher decomposition efficiency, resulting in more than 95% high efficiency treatment.

(4) biological treatment

The biological treatment method is to put a microorganism carrier rich in porosity and suitable for forming a microbial membrane in a container, and put microorganisms having excellent VOC decomposability into the carrier to introduce VOC-containing air into the microbial filter tower, which is a device with microorganisms attached to the carrier surface. In the microbial filter, the VOC is first attached to the carrier and fixed, and the attached VOC is removed by the microorganism by eating it.

Therefore, the incoming air requires a water spraying device in front of the microorganisms in order to maintain the temperature and humidity suitable for the activity and the humidity is maintained by intermittently spraying water onto the carrier to which the microorganisms are attached.

In addition, when intermittent inflow of microorganism-like VOC like the present device, it is necessary to separately supply microbial nutrients.

Then, with reference to the accompanying drawings, the description of each method that has been used or developed so far for the activated carbon adsorption method is as follows.

(1) non-removable adsorption tower (FIG. 1 method)

As shown in FIG. 1, the activated carbon 101 is charged into a simple container in the simplest manner, and then the VOC is passed through the adsorption to remove the adsorption.

However, this method has the following big problem

Since it is a simple device without a desorption regeneration device, activated carbon must be replaced when saturated with continuous adsorption of VOC, so there is an excessive problem of replacing activated carbon.

For example, in a facility where about 2000kg of organic solvent is used and evaporates a year, the activated carbon amount is about 10000kg and the replacement cost is about 15,000,000 won.

(2) Steam condensation and desorption VOC cooling condensation type desorption device (Fig. 2 method)

This method is a method that has been used until recently as a device for regenerating activated carbon by installing a desorption device in a way to improve the problem of the method of FIG. The operation of the desorption apparatus of the present method is performed during operation. The desorption and regeneration of the activated carbon 101 using steam heat is performed after condensation of the VOC and steam discharged after desorption in the condenser 4 and the solvent condensed in the oil / water separation tank 5. It is separated by water and treated.

This will be described in detail as follows.

The system is configured as shown in FIG. 2 to close the adsorption tower inlet damper 102 and the outlet damper 103 and open the inlet steam open / close valve 104 and the outlet steam open / close valve 105 in a state where the exhaust fan 2 is stopped. When the steam of 120 ~ 160 ℃ is blown, heat is applied to the VOC adsorbed on the activated carbon. As a result, the adsorbed VOC is evaporated and desorbed, and together with the steam, it enters the cooling water condenser (4) and cools and condenses the steam. Mainly condensed with organic solvent) and the condensed liquid is separated into the oil-water separation tank (5) at the bottom, and the wastewater is treated with wastewater and the organic solvent is treated separately.

This method requires a separate utility such as steam and cooling water, and the use of water and steam, using a corrosion-resistant material such as stainless has a disadvantage of expensive equipment.

(3) Burner combustion hot air desorption and desorption

(Fig. 3 method)

This method is a method that is used in recent years to improve the equipment cost and utility problems of the method of Figure 2 is a method of using a small capacity of the system used in the general direct combustion apparatus as a removable device.

Like this method, the desorption device is operated at the same time as in FIG. 2, and the desorption heat supply method uses hot air instead of the steam heat of FIG. 2, and the VOC generated during desorption is condensed and removed from the condenser using cooling water in the case of FIG. 2. Instead, it is heated by burner heat and heated to a high temperature decomposition temperature to process combustion decomposition.

In detail, the operating system of this type is burned and decomposed into VOCs by heating the air containing VOCs by 600 ° C. or more by the LNG combustion burner 700 which is a clean fuel in an idle state, and the decomposed air is purged air discharge pipe 16 The hot air at 600 ° C discharged to the outside and the outside air supplied by the outside air supply fan 10 are supplied with 200 ° C hot air heated by heat exchange from the heat exchanger 9 into the adsorption tower 1 to heat activated carbon 101. After desorption, the air containing VOC generated during desorption enters the combustion apparatus 7 directly by induction of the desorption air transfer fan 6, and is decomposed and decomposed to a combustion decomposition temperature of 600 ° C. or higher at the combustion burner 701. And catalytically purified by water vapor to be discharged to the atmosphere.

Here, the capacity of the desorption apparatus, that is, the air volume of the desorption air transfer fan 6, is 3 to 10% of the air volume of the exhaust fan 2, and a very small capacity is used.

However, this method uses burner combustion device using LNG as a clean fuel as a heat source for desorption hot air generation and pyrolysis, so it requires not only a separate fuel such as LNG, but also a complicated fuel supply line. There is a problem that is not suitable for use with.

In addition, since the combustion temperature must be raised to a high temperature of 600 ℃ or more, a large amount of fuel is consumed, and nitrogen oxides are generated due to a high flame temperature, which causes secondary air pollution.

In addition, since the desorption hot air temperature must be supplied below 200 ° C. due to the risk of fire, the heat recovery rate is low in the heat exchanger, so the high temperature hot air of 400 ° C is discharged into the atmosphere, resulting in high heat loss.

Due to various problems such as excessive fuel consumption, the direct combustion method is not used unless there is a catalyst poison in the air containing the VOC.

(4) burner combustion hot air desorption and desorption catalytic combustion purification desorption apparatus for VOC

(Fig. 4 method)

This method is a method that has been used in recent years to improve the equipment cost and utility problems of the method of FIG. 2 as in the method of FIG. 3, and the method of FIG.

This method adopts catalytic combustion instead of direct combustion in order to improve the excessive fuel consumption of FIG.

2 and 3, the operation of the desorption device is performed in the same manner as in FIGS. 2 and 3, and the desorption heat supply method uses hot air instead of the steam heat of the method of FIG. 2, and the VOC generated during the desorption in the condenser using the cooling water in the case of the method of FIG. Instead of condensation and removal, the catalyst is heated by burner heat to the catalytic decomposition temperature.

Specifically, the operating system of this type is a hot air and an outside air supply fan 10 of 300 ° C. or more in which air heated by the LNG combustion burner 701 which is a clean fuel in an idle state is discharged to the purified air discharge pipe 16. By supplying the hot air of 170 ℃ heated by heat exchange in the heat exchanger (9) into the adsorption tower (1) to the outside air supplied by the activated carbon 101 heat desorption, the air containing VOC generated during desorption is desorption air transfer fan ( 6) to enter the catalytic combustion device (8) again to increase the temperature of the catalytic decomposition temperature in the combustion burner 701 to 200 ℃ or more and then catalytically purify the carbon dioxide and water vapor from the catalyst 803 to be discharged to the atmosphere That's the way.

Here, the capacity of the desorption apparatus is 3-10% of the air flow rate of the exhaust fan 2 as in the method of FIG.

However, this method uses burner combustion device using LNG as a clean fuel as a heat source for desorption hot air generation and catalytic decomposition, so it requires additional fuel such as LNG and additionally complicated fuel supply line. There is a problem that is not suitable for use in dosage.

In addition, when the catalyst poison in the air containing VOC is contained, it is difficult to use, and as in FIG. 3, nitrogen oxides are generated due to a high flame temperature, thereby causing secondary air pollution.

(5) Catalytic combustion purification desorption apparatus for desorption and desorption of heater hot air

(Figure 5)

This method is to replace the heat source with a heater suitable for small capacity to solve the need for a separate fuel, the additional fuel supply line and the problem of generating nitrogen oxides due to the high temperature flame, which is a problem of using the LNG as a heat source in FIG. That's the way. Similarly to the method of FIG. 3, the detachable device is operated at rest.

In the desorption method, hot air of 300 ° C. in which air heated by the heater 801 is discharged to the purge air discharge pipe 16 and outdoor air supplied by the outside air supply fan 10 are heated by heat exchange in the heat exchanger 9. By supplying the hot air of ℃ ℃ into the adsorption tower (1) by heating and desorption of activated carbon 101, the air containing the VOC generated during the desorption enters the catalytic combustion device (8) again by the induction of the desorption air transfer fan (6) heater 801 In this case, the catalyst is heated to 200 ° C, which is a catalytic decomposition temperature, and then catalyzed by carbon dioxide and water vapor in the catalyst 803 to be discharged to the atmosphere in a purified state.

Here, the capacity of the desorption apparatus is 3 to 10% of the air flow rate of the exhaust fan 2, and a very small capacity is used.

However, in the case of heater heating of FIG. 5, the heating of the air introduced into the catalytic device is immediately performed, and the temperature is immediately raised to 200 ° C. or higher necessary for catalytic decomposition, but in the case of the heater, the time required for heating the heater and the casing around the heater. After a considerable time (experiment of 1-2 hours), the temperature is raised to 200 ℃ or higher, which is necessary for catalytic decomposition. .

(6) Heat purifier desorption and desorption VOC biological desorption apparatus

(Fig. 6 method)

This method is unreasonable compared to the method of Figures 4 and 5, but is used as a real product in recent years and also shown to be related to the present invention.

Similarly to the method of FIG. 3, the detachable device is operated at rest.

In FIG. 6, the desorption method supplies 170 占 폚 hot air heated by the outside air supply fan 10 and the heater 801 into the adsorption tower 1 to desorb and heat the activated carbon 101. The air containing the VOC generated during desorption is desorbed. The hot air is cooled to a temperature suitable for microbial decomposition with water injected into the microbial filter tower 11 by the induction of the air transfer fan 6 and injected by the circulation pump 12 from the bottom of the microbial filter, and the cooled VOC is a microbial filter ( Purified by microorganisms while passing through 1101.

In addition, since the desorption device is only intermittent during operation, the circulating pump 12 is operated at a predetermined time to protect the microorganisms even when the desorption device is not operated, thereby spraying the water containing the nutrient into the microbial filter 1101. Provide moisture. At this time, since mist is discharged during water injection, the mist is removed by installing a demister 1102.

However, this method has some problems

First, microbial decomposition is easy to decompose odorous substances such as hydrogen sulfide and ammonia, but organic compounds with high molecular weight such as VOC are not easy to decompose, and some substances also contain poorly decomposable substances that do not decompose well. Even if the residence time is long, high efficiency decomposition may be difficult depending on the type of VOC.

Secondly, the desorbed VOC concentration comes out at a low concentration initially and gradually increases as the activated carbon is heated, and is discharged at a high concentration of several thousand ppm. The microbial treatment method has good decomposition efficiency at low concentrations of several ten ppm or less, but when the concentration increases, There is a problem that the degradation efficiency is low.

Third, the biological treatment method requires continuous feeding for the survival of the microorganisms, but since the facility operates only intermittently (eg 10 hours a week) as described above, the microorganisms feed VOCs intermittently. Therefore, there is a problem that must be supplied with a separate nutritional supplement.

Fourth, there is a problem in that wastewater is generated as water is continuously supplied for the maintenance of moisture of the microbial carrier and the sludge of the microorganisms excessively generated by the growth of the microorganisms at a predetermined time and the cooling of the incoming hot air.

Fifth, since the microorganism carrier is required several times larger than the residence time in the general microbial carrier for the high efficiency decomposition of the organic compound of the high concentration of the polymeric material, there is a problem in that the size of the device is increased and the equipment cost is increased.

The desorption and regeneration method of the adsorption tower, which has been reviewed so far, has been developed or developed and used as a real product. Each method has its own characteristics, but each method has big and small problems and needs to be improved in terms of economics. .

Therefore, the present invention has come to devise an excellent method in terms of equipment costs and operating costs, unlike the conventionally used method, there is almost no problem in use.

The present invention is a method for treating the desorbed by hot air and the desorbed VOC in the installation of the desorption apparatus for economically operating the activated carbon adsorption system (Figs. 2, 3, 4, 5, 6) To minimize the problem of the system and to devise a more economic way than the previous method.

First of all, the technical problem is expressed as follows to solve the problems of each method.

(1) There are various types of VOC purification devices such as adsorption method, combustion method, biological treatment method, etc., but other adsorption methods such as 1 / 5-1 / 10 use cheap adsorption method to solve the problem of excessive activated carbon consumption. Would be the way equipped.

(2) The method of solving the problems of the conventional method (FIG. 2 method), that is, a separate utility such as steam and cooling water is unnecessary and should be an inexpensive method using ordinary steel instead of corrosion-resistant materials such as stainless steel.

(3) The method of solving the problems of the conventional method (Fig. 3 method), that is, a method of using energy as electricity, a method that does not require a separate fuel such as LNG, consumes less energy, and has no risk of fire.

(4) The method of solving the problem in the conventional method (Fig. 4 method), that is, the energy should be used as a way that can be used normally even if there is no need for a separate fuel, such as LNG and catalyst poison.

(5) Solving the problem in the conventional method (Fig. 5 method), that is, part of the VOC desorbed due to low catalytic decomposition efficiency due to the delay of heating up to the temperature required for catalytic decomposition by using a heater which is electric energy in the catalytic device. It should be a way to solve the problem of being discharged into the atmosphere instead of water.

(6) The method of solving the problem in the conventional method (Fig. 5 method), that is, high efficiency decomposition should be made regardless of the first type of VOC, and second, the efficiency of decomposition should be excellent regardless of the concentration of VOC desorbed, and third generation of intermittent VOC Fourth, it should be operated without chemicals. Fourth, there should be no secondary pollution such as wastewater. Fifth, general desorption equipment installation cost should be low for high efficiency decomposition of organic compounds with high concentration of high molecular materials.

(7) As a result, it should be the most economical way to minimize the problems of the previous method and at the same time the equipment cost and operation cost are low.

In order to achieve such a technical problem, the apparatus is configured as shown in FIG. 7 by applying a photocatalyst method as a removal method of the desorbed VOC.

An activated carbon adsorption tower (1) having an inlet opening / closing damper (102) and an outlet opening / closing damper (103), and an exhaust fan (2) and a stack (3) for guiding air during operation of the adsorption tower,

It is a device that desorbs and regenerates activated carbon during operation, and installs an external air supply fan 10 and a heater 801, which are desorption hot air supply devices, and desorbs and transfers the VOCs desorbed by hot air with a desorption and decomposition removal device. ) And a small capacity photocatalyst 13 are installed.

Hot air supply pipe (14) for supplying desorption hot air to the pipe connecting each device, desorption air transfer pipe (15) through which air containing desorption VOC flows, and purge air discharge pipe (16) for discharging air purified by a photocatalyst to the outside Install).

1 is a flow chart of a non-removable general adsorption tower

2 is a flow chart of a cooling condensation type desorption apparatus for steam heat desorption and desorption VOC.

3 is a flow chart of a direct combustion purification type desorption apparatus for burner combustion hot air desorption and desorption VOC.

Figure 4 is a flow chart of the catalytic combustion purification desorption apparatus of burner combustion hot air desorption and desorption VOC

5 is a flowchart of catalytic combustion purification desorption apparatus for heater hot air desorption and desorption VOC.

6 is a flow chart of a biological treatment purification desorption apparatus for heater hot air desorption and desorption VOC.

7 is a flowchart of the photocatalytic purification desorption apparatus for heater hot air desorption and desorption VOC.

8 is a detailed view of the interior of the photocatalyst purification apparatus of the desorbed VOC

* Explanation of symbols for main parts of the drawings

1 ....... Adsorption Tower 101..Activated Carbon

102.Adsorption tower inlet / opening damper 103 ... Adsorption tower inlet / opening damper

104.Inlet steam open / close valve 105 ... Outlet steam open / close valve

2 ....... exhaust fan 3 ....... binder

4 ....... Condenser 5 ....... Oil Separator

6 ....... Removable Air Transfer Fan 7 ....... Direct Combustion Device

701 ... LNG combustion burner

801 ... heater 802 ... hot air temperature controller before catalyst

803 Catalyst 9 ....... Heat Exchanger

10 ..... Air supply fan 11 ..... Microorganism filter tower

1101.Microbial filter 1102.Demister

1103..Microbial nutrient inlet 12 ...... Circulation pump

13 ...... Photocatalyst 1301.Titanium Dioxide Coating Plate

1302 ... Ultraviolet lamp 14 ....... Hot air supply pipe

15 ...... Removable air transfer pipe 16 ...... Purified air discharge pipe

At the core of the present invention can be driven into the following two.

First, there are many types of VOC purifiers and equipment cost can vary according to various design conditions such as process gas volume, type and concentration of VOC.

For example, if the processing gas volume of the automobile coating booth is 300㎥ / minute, the simple adsorption tower, which is the method of FIG. 1, may be about 30 million won, but the other method is expensive, from 100 million won to 350 million won.

Therefore, since the simple adsorption tower of FIG. 1 is superior in terms of equipment cost, the activated carbon adsorption method is basically used. However, as described above, the simple adsorption method is required to replace the activated carbon when the activated carbon becomes saturated, so the activated carbon replacement cost is high. For example, when 3000L of paint is used in an automobile booth, about 2000kg of organic solvent is evaporated. The activated carbon amount is about 10000kg and the replacement cost is about 15,000,000 won.

As a result, the most economical method is to use an activated carbon adsorption tower with significantly lower equipment costs, but to have a desorption and regeneration device to reduce the consumption of activated carbon.

Second, if the basic system adopts the method of equipping the activated carbon adsorption column with the desorption regeneration device, the important thing in the same method depends on the selection of the desorption / regeneration device of the various methods, and the selection criteria are excellent in the efficiency of decomposition, low equipment cost and operation cost, The problem should be the least.

Therefore, the present invention is unlike any other method currently developed or used as a desorption and regeneration device in activated carbon adsorption tower (FIGS. 2, 3, 4, 5, and 6). Compared to the method, an inexpensive photocatalyst method is adopted.

The photocatalyst method has been difficult to apply to actual products because of the early stages of technological development only a few years ago, which is not only limited to materials that are expensive and coated with titanium dioxide which causes photocatalytic reactions, but also has a problem of poor quality. As a result, it is possible to commercialize by developing titanium dioxide film on various materials that can be called as the core technology of photocatalyst method in a good and cheap way and the development of powerful and inexpensive UV lamps. The choice was made because of the superior economics compared to the method or the biological method.

In conclusion, the contents of the present invention are briefly described as a device for desorption and regeneration of activated carbon in the adsorption tower. The hot air is generated by a heater and a small fan and blown into the activated carbon in the adsorption tower to desorb the VOC adsorbed on the activated carbon. It is a device equipped with a series of systems that are sucked into a small fan and passed through a photocatalyst to be removed.

Referring to the photocatalyst device which is a desorption device used in the present invention in detail.

The photocatalyst method is a device that oxidizes and reduces VOCs to carbon dioxide and water vapor by using holes and electrons generated on the surface of titanium dioxide when ultraviolet rays are irradiated onto the surface of titanium dioxide. The principle is as follows.

When light of a specific wavelength such as ultraviolet light is applied to a surface having semiconducting properties such as titanium dioxide, holes (hole h ⁺ ) and electrons (e ⁻ ) are separated from the outermost electron band and conduction band inside the surface.

The electrons generated in this process reduce the reactants and oxidize the holes. That is, oxygen molecules are activated by the activation of holes and electrons on the surface of titanium dioxide. Activated oxygen molecules produce hydroxy radicals, which result in the presence of several intermediates with various radicals, which are eventually converted to carbon dioxide.

E: O ₂ + e ^- → O ₂ activity Organic decomposition, odor removal

Hole: H ₂ O + h ⁺ → (· OH) + H ⁺ Oxidative Decomposition of Organics

Factors affecting the photocatalytic reaction include the properties of the titanium dioxide film, the intensity and wavelength of ultraviolet light, the flow characteristics of the system, the concentration and composition of the material to be treated, and the possibility of recombination of electrons and holes.

The characteristic of photocatalytic reaction is to oxidize molecules by generating high energy corresponding to 30000K of thermal energy at room temperature, which has the advantage of simple device and low operating cost.

As the structure of the photocatalyst device applied in the present invention can be considered various structures, as shown in FIG. 8 as a detail of the photocatalyst device that is a desorption VOC decomposition device, a honeycomb-shaped titanium dioxide coating plate 1301 is made. One long ultraviolet lamp 1302 is installed at the center of each hexagonal column of the honeycomb to secure a wide reaction area. The ultraviolet light is located at the center of the hexagon, so that uniform and strong ultraviolet light is irradiated on the entire reaction surface. It was configured to be.

Next, the driving method will be described in detail with reference to FIG. 7.

Adsorption tower at idle. When the outlet dampers 102 and 103 are closed and the exhaust fan 2 is stopped, the desorption unit is operated. When the push switch is pressed, the outside air supply fan 10 and the heater 801 are activated to generate hot air, and at the same time, the desorption air transfer. The fan 6 is operated and the ultraviolet lamp 1302 of the small photocatalyst device is turned on. Then, the generated hot air is blown into the adsorption tower 1 along the hot air supply pipe 14 by the blowing force of the outside air supply fan 10, and the hot air introduced into the adsorption tower heats the activated carbon 101 to adsorb the VOC. The desorbed VOC flows through the desorption air transfer pipe (15) by the suction of the desorption hot fan (6) and enters the photocatalyst (13) and enters the photocatalyst (VOC). Is decomposed and purified into carbon dioxide and water vapor by photocatalytic reaction on the surface of the activated honeycomb-shaped titanium dioxide coating plate 1301 that is irradiated with an ultraviolet lamp 1302, and is discharged into the atmosphere through the stack 3. When this process is operated for 3-10 hours, the activated carbon 101 is mostly desorbed and regenerated.

The present invention has been improved as follows compared to the previous method.

First of all, the most problematic problem in adsorption method is that if a certain amount of VOC is adsorbed, it becomes saturated and VOC is not removed, so the activated carbon must be replaced. It can save tens of millions of won in activated carbon replacement costs.

Secondly, as the desorption and regeneration device that has been used mainly in the past, as shown in FIG. 2, the desorption and desorption by steam heat during operation has been used by the method of removing condensation by cooling condensation, but the equipment cost is high and cooling water and steam, etc. There is a problem that a separate utility is required. By using a small photocatalyst device, the method of catalytic decomposition of VOC generated during desorption and desorption by hot air is required. Can be obtained.

Thirdly, among the methods using catalytic decomposition of VOCs generated during desorption and desorption by hot air, burner combustion such as LNG, which mainly uses a heat source, has been used but generally used in desorption equipment. Since the catalytic combustion device has a small capacity, additional fuel is required rather than the advantages of the burner method, and the disadvantage of the increase in the equipment cost due to the fuel supply device is that the present invention changes the heat source to the heater method. The effect of solving this can be obtained.

Fourth, in the case of desorption by hot air using a heat source as a heater and catalytic decomposition of VOCs generated during desorption, VOCs generated during desorption are always removed with high efficiency and thermal efficiency is prevented while preventing the risk of fire and desorption efficiency. In the case of heater heating, the heating of the air flowing into the catalytic device is immediately performed, and the temperature is raised to 200 ℃ or higher necessary for catalytic decomposition. However, in the case of the heater, heater and heater After heating the surrounding casing for a considerable time (1 to 2 hours as a result of the experiment), the temperature is raised to 200 ℃ or higher, which is necessary for catalytic decomposition. The photocatalyst had a problem of being discharged into the Since up the right high-efficiency decomposition reaction in the coated plate it can be obtained that can effect efficient removal from the initial desorption unlike the catalytic combustion reaction.

Fifthly, in the case of microbial method, if desorption is intermittently performed like this facility, VOC is intermittently discharged, and it needs to be supplied separately with microbial nutrients, and the VOC emission concentration itself is thousands of ppm, which is not suitable for decomposition into microorganisms. While it is difficult to remove and also has various problems such as waste water generation, this design method does not have any such problems, so it has better desorption efficiency than microbial treatment method, and has simple operation and convenient maintenance. .

As a result, the present invention is effective in solving the problems of various conventional methods and at the same time, the process gas is simple and the desorption VOC purifier used in the photocatalytic method, direct combustion method, catalytic combustion method, biological treatment method, etc. The lowest amount per 1㎥ / minute, the equipment cost is not only significantly lower, but also the lowest in terms of operating costs, such as power costs, so it is an economic method.

Claims (1)

In constructing the system as a facility that is applied to a device for desorption and regeneration of activated carbon in the activated carbon adsorption column Activated carbon adsorption tower (1) equipped with adsorption tower inlet and outlet air blocking mouth and outlet opening / closing damper (1) and honeycomb-shaped titanium dioxide coating plate (1301) in the enclosure and UV lamp 1302 enters the center of the honeycomb coating plate. Equipped with a photocatalyst 13 having a structure Hot air supply device for installing a heater 801 to the outside air supply fan 10 and the rear end to put the removable hot air; A desorption air transfer fan (6) positioned in front of the photocatalyst to suck desorption hot air to the photocatalyst; As a pipe to connect each of these devices A hot air supply pipe 14 connecting the hot air supply device and the adsorption tower; Desorption air transfer pipe (9) for connecting from the adsorption tower to the photocatalyst via the desorption air transfer fan; A photocatalyst purification desorption apparatus for hot air desorption and desorption volatile organic vapors, comprising a system having a series of systems of purge air discharge pipes (16) connecting from a photocatalyst to a stack.