KR101738106B1

KR101738106B1 - Scrubber system

Info

Publication number: KR101738106B1
Application number: KR1020150093606A
Authority: KR
Inventors: 김태우; 김민용; 김영환; 김정식; 정붕익
Original assignee: (주) 테크윈
Priority date: 2015-06-30
Filing date: 2015-06-30
Publication date: 2017-05-29
Also published as: KR20170003221A

Abstract

A scrubber having a gas inlet through which a gas to be treated flows, a process gas outlet through which the introduced gas is treated, and a process water outlet through which the process water treated by the introduced gas is discharged; A lamp capable of irradiating light within the scrubber to accelerate the generation of highly reactive radicals from the cleaning liquid, and a control unit for controlling the lamp, And a photocatalyst provided in the scrubber for promoting radical generation from the cleaning liquid.

Description

Scrubber system [0002]

The present invention relates to a scrubber system capable of wet processing VOCs, odor, and acid gas (NOx, SOx, etc.) discharged from an internal combustion engine, an incinerator and various environmental facilities.

Since general air pollution control facilities are limited in performance in a specific target gas, in the case of a plurality of objects to be treated, two or more kinds of processing facilities may be connected in series, or the operation itself may be limited.

Although SCR has excellent NOx removal performance, operation is limited if particulate contaminants or SOx components are contained in a large amount on the gas to be treated. In order to solve this problem, a dust collecting apparatus or a wet scrubbing apparatus may be provided at the front end, but there is a problem that the SCR performance due to the operation temperature drop may be problematic.

On the other hand, sodium hypochlorite (NaOCl), which can be produced through the electrolysis of brine, has been evaluated as a cleaning liquid for a wet cleaning facility capable of simultaneously removing the gaseous pollutants listed above, regardless of the source.

However, in the case of VOCs containing aromatic components or carbon monoxide (NO) close to water-insoluble, there is a limitation in that the treatment speed is slow and operation is required at low pH or a high concentration of cleaning liquid is required.

Korean Patent Application No. 10-2006-0003979

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a method and apparatus for promoting the decomposition of aromatic components and the oxidation of NO gas in the application of sodium hypochlorite produced using brine, And an object of the present invention is to provide an improved scrubber system.

According to an aspect of the present invention, there is provided a scrubber system including a gas inlet through which a gas to be treated flows, a process gas outlet through which the introduced gas is processed, A scrubber having an outlet; An electrolytic water supply device for supplying a cleaning liquid generated by electrolyzing raw water into the scrubber and treating the target gas introduced through the gas inlet to remove harmful substances; A lamp capable of irradiating light within the scrubber to promote generation of highly reactive radicals from the cleaning liquid; And a photocatalyst disposed inside the scrubber to promote radical generation from the cleaning liquid.

The photocatalyst preferably contains at least one semiconductor component selected from titanium oxide, tungsten oxide, ceramic, silver, zinc oxide, tin oxide, iron oxide, platinum, palladium, molybdenum, boron and niobium and a transition metal.

It is preferable that the photocatalyst is applied to a surface of any one of a metal plate, a glass fiber and a porous plate provided inside the scrubber.

It is preferable that the cleaning liquid contains sodium hypochlorite.

In addition, the lamp preferably includes an electrodeless lamp or an LED lamp capable of irradiating ultraviolet rays.

It is also preferable that the photocatalyst, the lamp, and a jetting portion for jetting the cleaning liquid are sequentially disposed on the basis of the movement route of the target gas.

The apparatus may further include a treatment water processing unit for removing foreign substances contained in the treatment water used for the target gas treatment in the scrubber and circulating the same.

Further, the inner space of the scrubber is divided into two or more stages, and the photocatalyst, the lamp, and the jetting portion for jetting the cleaning liquid are successively installed in each of the spaces partitioned by the multi-stages or in a space of a specific stage good.

The electrolytic water supply device may further include: an electrolytic bath for electrolyzing the treated water in the scrubber; A first supply pump for pumping treatment water in the scrubber to the electrolytic bath; And a first jetting unit for jetting the cleaning liquid generated by electrolysis in the electrolytic bath at the top of the lamp and the photocatalyst in the scrubber.

The electrolytic water supply device may further include: a recovery tank for recovering the cleaning liquid accumulated in the scrubber; A second jetting section for jetting the cleaning liquid in the recovery tank from above the lamp and the photocatalyst in the scrubber; And a second supply pump for pumping the cleaning liquid in the recovery tank to the second jetting unit.

The apparatus may further include a third jetting unit for jetting the cleaning liquid pumped into the electrolytic bath from the first supply pump at a downstream side of the photocatalyst in the scrubber.

According to the scrubber system of the present invention, by providing an ultraviolet lamp and a photocatalyst in the scrubber, it is possible to increase oxidation and absorption efficiency of harmful substances contained in the gas to be treated (target gas). In particular, it contributes greatly to improve the oxidation and decomposition rates of aromatic components and nitrogen monoxide gas, which are difficult to decompose easily with an aqueous sodium hypochlorite solution, thereby increasing the removal rate of harmful substances.

In addition, since the concentration of sodium hypochlorite aqueous solution can be lowered or the pH condition can be increased, it is possible to reduce the energy required for producing the cleaning liquid, thereby obtaining economical advantages.

1 is a schematic diagram showing a scrubber system according to an embodiment of the present invention.
Fig. 2 is an enlarged cross-sectional view of a principal portion A of the photocatalyst shown in Fig. 1;
3 is a schematic diagram showing a scrubber system according to another embodiment of the present invention.
FIG. 4 is a graph showing experimental results of the NO removal ratio according to whether the lamp is installed or not and the photocatalyst is installed under the condition of Experimental Example 1. FIG.
FIG. 5 is a graph showing experimental results on the presence or absence of a photocatalyst and the presence or absence of a lamp according to Experimental Example 2. FIG.

Hereinafter, a scrubber system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2, a scrubber system 10 according to an embodiment of the present invention includes a scrubber 20, an electrolyzed water supply device 30, a lamp 40, and a photocatalyst 50.

The scrubber 20 has a gas inlet 21 into which a gas to be treated flows, a process gas outlet 22 which is discharged after the introduced gas is processed, and a process water outlet 23). The scrubber 20 is further provided with a raw water inlet 24 into which raw water flows and a cleaning liquid inlet 25, a cleaning liquid outlet 26 and a treated water inlet 27.

The raw water inlet 24 is installed in the lower portion of the scrubber 20. The raw water introduced through the raw water supply line 80 may include any one of seawater, brine, fresh water and fresh water, , It can be supplied in a treated state so as to generate sodium hypochlorite upon electrolysis by adding a specific electrolyte.

The target gas flowing into the gas inlet 21 is oxidized and absorbed by the cleaning agent in the scrubber 20 to be treated to remove harmful substances and the process gas from which harmful substances are removed is disposed on the top of the scrubber 20 Through the gas outlet 23, to the next processing step. The target gas to be treated in this manner may be atmospheric pollutants such as VOCs, NOx, SOx, and the like.

The treated water outlet 22 is provided in the lower portion of the scrubber 20 and is supplied to the inside of the scrubber 20 to discharge the treated water oxidizing and absorbing the noxious gas. And can be recovered after being processed in the water treatment section 60. The treatment water treatment section 60 includes a treatment tank 62 for separating and treating sludge and foreign substances in the treatment water discharged from the treatment water discharge line 61, And a treated water recovery line 63 that is recovered into the scrubber 20 through the treated water recovery port 27. The sludge and foreign substances separated in the treatment tank 62 are transferred to the next process through the discharge line.

The electrolytic water supply device 30 includes an electrolytic bath 31, a supply pump 32, and a cleaning liquid spraying unit 33.

The electrolytic bath 31 is provided on the cleaning liquid supply line 34 and electrolyzed the cleaning liquid (including the raw water) pumped from the inside of the scrubber 20 by the supply pump 32 and electrolyzed, That is, sodium hypochlorite is supplied to the jetting section 33. The electrolytic bath 31 is provided with an anode and a cathode inside, and electrolyzes the raw water by a power source supplied from a power supply unit (not shown) to generate a cleaning liquid (sodium hypochlorite). The electrolytic bath 31 can be either a galvanized membrane or a non-diaphragm electrolytic bath. When electrolyzing the brine or seawater in the electrolytic bath 31 as described above, a cleaning liquid (oxidant: NaOCl) having a pH of about alkaline range (8 to 11) is produced, and the cleaning liquid containing such oxidizing agent And is supplied to the jetting section 33 through the cleaning liquid supply line 34.

The jetting section 33 includes a plurality of jetting nozzles. The jetting section 33 is installed in the upper part of the lamp 40 in the scrubber 20, and may be installed in multiple stages at different heights. Thus, the cleaning liquid injected from the jetting section 33 oxidizes and absorbs the target gas, that is, the harmful substance contained in the air pollutant, and removes it.

The lamp 40 is installed inside the scrubber 20 to emit visible light and ultraviolet light, and may preferably include an electrodeless lamp or an LED lamp. Since the light irradiated from the lamp 40 includes ultraviolet rays of a specific wavelength range or the like, it is possible to generate radicals having excellent reactivity when irradiated to a cleaning liquid, that is, an aqueous solution of sodium hypochlorite, thereby increasing its role as an oxidizing agent, It is possible to contribute to improving the decomposition and oxidation rate of aromatic components and nitrogen monoxide gas which are difficult to decompose easily.

The photocatalyst 50 is provided inside the scrubber 20 to promote radical generation from the cleaning liquid, thereby contributing to improvement of decomposition and oxidation rate of an aromatic component or nitrogen monoxide gas which is difficult to easily decompose sodium hypochlorite. The photocatalyst 50 preferably contains at least one semiconductor component selected from titanium oxide, tungsten oxide, ceramic, silver, zinc oxide, tin oxide, iron oxide, platinum, palladium, molybdenum, boron and niobium and a transition metal. As shown in FIG. 2, the photocatalyst 50 may be formed on the surface of the metal plate 51 provided inside the scrubber 20.

The photocatalyst 50 may have a structure formed by coating the surface of a glass fiber or a perforated plate provided in the scrubber 20 and may further be applied to an inner wall surface of the scrubber 20. [

Also shown in Figure 3 is a scrubber system 10 'in accordance with another embodiment of the present invention. The same components as those of the scrubber system 10 described above with reference to FIGS. 1 and 2 among the components of the scrubber system 10 'shown in FIG. 3 are denoted by the same reference numerals, The description is omitted.

3, the scrubber system 10 'divides the inner space of the scrubber 20 into a lower chamber 20a and an upper chamber 20b, and a partition wall (not shown) And a cover 73 installed to cover the upper portion of the barrel portion 71 and preventing the process water used in the upper chamber 20b from falling into the lower chamber 20a is further provided . The barrel portion 71 is formed at a central portion of the partition wall 70 and is formed at a predetermined height at an upper portion so that a target gas of the lower chamber 20a is passed to the upper chamber 20b. The partition 70 is horizontally installed inside the scrubber 20 and is used as high as the height of the barrel portion 71 on the upper portion of the partition 70, The cover 73 is spaced apart from the upper portion of the barrel portion 71 so as to cover the upper portion of the barrel portion 71. The cover 73 is inclined downwardly from the center toward the rim, So that it is guided in the upper space of the guide plate 70.

The upper chamber 20b and the lower chamber 20a are sequentially provided with a photocatalyst 50, a lamp 40 and jetting parts 133 and 137 for jetting the cleaning liquid, respectively.

The scrubber system 10 'includes a cleaning liquid supply device 130. The cleaning liquid supply device 130 receives the cleaning liquid (including raw water) in the lower chamber 20a through the cleaning liquid supply line 134 A first supply pump 132 for pumping the treated water in the lower chamber 20a to the electrolytic bath 131 and a cleaning liquid electrolyzed in the electrolytic bath 131. The electrolytic bath 131, And a first jetting section 133 for jetting the air from the lamp 40 and the photocatalyst 50 in the photocatalyst 20a.

The electrolytic water supply device 130 may further include a recovery tank 136 for recovering the cleaning liquid accumulated on the upper portion of the partition wall 70 in the upper chamber 20b through the recovery line 140, The second jetting section 137 for jetting the cleaning liquid in the tank 136 from the lamp 40 inside the upper chamber 20b and the photocatalyst 50 and the cleaning liquid in the recovery tank 136 to the second jetting section 137, And a second supply pump 138 installed in the cleaning liquid supply line 139 to pump the liquid to the cleaning liquid supply line 139. [ Raw water may be supplied to the recovery tank 136 through the branch line 61 separated from the raw water supply line 60 and replenished with some or all of the washing water containing sludge or foreign matter in the recovery tank 136 May be withdrawn through the scrubbing liquid inlet 28 at the bottom of the scrubber 20 into the scrubber 20 through the discharge line 141. That is, since the target gas moved to the upper chamber 20b has a relatively reduced amount of harmful substances, the washing water used in the upper chamber 20b can be used as it is without electrolyzing the raw water (salt water, seawater, etc.). Therefore, most of the harmful substances contained in the target gas can be removed using the aqueous solution of sodium hydroxide in the lower chamber 20a. The remaining harmful substances can be removed from the washing liquid (raw water) sprayed from the upper chamber 20b, 40 and the photocatalyst 50, respectively.

The apparatus further includes a third jetting unit 135 for jetting the cleaning liquid pumped from the first supply pump 132 to the electrolytic bath 131 downstream of the photocatalyst 50 in the lower chamber 20b Do. Therefore, the object gas is first treated with a cleaning liquid containing raw water or raw water, then secondarily treated with a cleaning liquid containing an aqueous sodium hypochlorite solution, and then the cleaning liquid (raw water) is sprayed from the upper chamber 20b three times It is possible to effectively treat harmful substances.

Meanwhile, in the case of the scrubber system 10, 10 'according to the embodiment of the present invention having the above-described structure, by using sodium hypochlorite aqueous solution produced by electrolyzing salt water which is easily supplied and stored, The decomposition of aromatic components and the oxidation of nitrogen monoxide gas can be accelerated in oxidizing and absorbing harmful substances and this can be more effectively achieved by the role of the lamp 40 and the photocatalyst 50 provided inside the scrubber 20 .

As an example, when TiO ₂ is used as a photocatalyst, the contaminants are decomposed according to the following reaction formulas 1 to 6 in an advanced oxidation treatment process.

[Reaction Scheme 1]

TiO ₂ + hv -> TiO ₂ (h ⁺ ) + TiO ₂ (e ^- )

[Reaction Scheme 2]

OH ^- + TiO ₂ (h ⁺ ) -> TiO ₂ + OH

[Reaction Scheme 3]

H ₂ O + TiO ₂ (h ⁺ ) -> TiO ₂ + H ⁺ + · OH

[Reaction Scheme 4]

TiO 2 (e ^- ) + O ₂ -> TiO ₂ + O ₂ ^-

[Reaction Scheme 5]

O ₂ ^- + H ⁺ ^- & gt ^; H ₂ O

[Reaction Scheme 6]

OH + M -> degradation product

When brine is electrolyzed, Cl _{2 (g)} is generated in the anode and dissolved in water to be present in the form of HOCl and OCl ^- , acting as an oxidizing agent. At this time, radicals can be generated in the form of the following reaction formulas 7 to 9 by the light (ultraviolet ray) irradiated from the lamp 40, and in the case where the washing liquid is an acidic condition,

[Reaction Scheme 7]

HOCl + hv -> OH + Cl

[Reaction Scheme 8]

OCl ^- + hv -> O ^- + Cl ^-

[Reaction Scheme 9]

Cl ₂ + hv - > H ₂ O + Cl

[Reaction Scheme 10]

HOCl ^- + H ⁺ -> H ₂ O + Cl

[Reaction Scheme 11]

Cl + Cl ^- - > Cl ₂ ^-

Hereinafter, the results obtained by checking the removal rate of nitrogen monoxide (NO) according to the type of cleaning liquid, the presence of UV and the photocatalyst through experiments using the Lab-scale wet cleaning equipment will be described.

The experimental conditions are shown in Table 1 below.

Item unit Condition Cleaning liquid NaCl aqueous solution The gas to be treated (NO) mL / m 3 800 (N ₂ bal.) UV wavelength UV-C TiO ₂ wt.% 10%

Referring to Table 1 and FIG. 5, when 3% of the salt water was injected into the NO gas, no NO was removed at the flow rate range, whereby sodium and chlorine ions present in the aqueous solution could act as NO oxidizing agents It can be confirmed that there is no.

As shown in Experimental Example 1, when the TiO ₂ was coated on the inner wall of the absorber (scrubber) and 3% of the brine was sprayed while UV-C was irradiated, it was confirmed that the NO removal rate was up to 13% It can be judged that the hydroxyl radical serves as an oxidizing agent.

The experimental conditions are shown in Table 2 below.

Item unit Condition Cleaning liquid NaOCl Cleaning liquid concentration mg_Cl ₂ / L 8000 The gas to be treated (NO) mL / m 3 800 (N ₂ bal.) UV wavelength UV-C TiO ₂ wt.% 10%

Referring to Table 2 and FIG. 6, when the aqueous sodium hypochlorite solution obtained by electrolysis of the brine was injected into the NO gas, it was confirmed that the NO removal rate was 38.3% ~ 60.4% in the flow rate range. When the UV-C alone was added to this, the removal rate was increased by about 15%, and when TiO ₂ was applied to the inside of the absorption tower, the removal rate was increased by more than 40%. It can be concluded that the addition of chemical species that can act as an oxidant in addition to hydroxyl radicals by UV and photocatalyst promoted the oxidation and removal of NO.

As can be seen from the description and experimental examples described above, the lamp 40 for irradiating ultraviolet rays and the photocatalyst 50 are provided together inside the scrubber 20, so that the oxidant obtained by electrolyzing raw water, that is, an aqueous solution of sodium hypochlorite It is possible to promote the generation of radicals having high reactivity inside the scrubber 20. In this case, Therefore, it is possible to improve the decomposition and oxidation rate of aromatic components and nitrogen monoxide gas which are difficult to decompose easily with an aqueous solution of sodium hypochlorite, and the treatment efficiency of the target gas can be increased.

In addition, since the removal efficiency of harmful substances through the lamp 40 and the photocatalyst 50 can be increased, the concentration of the cleaning liquid can be lowered or the pH condition can be increased. Therefore, energy required for the production of the cleaning liquid Etc.) can be reduced, so that a great advantage can be obtained not only in terms of technology but also economically.

Meanwhile, in another embodiment of the present invention, the inner space of the scrubber is divided into the upper chamber and the lower chamber. However, this is merely an example, and the inner space of the scrubber may be divided into a plurality of divided spaces , A lamp, a photocatalyst, and a jetting portion may be provided only in at least one of the divided stages (chambers), or both may be installed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Those skilled in the art will readily appreciate that many modifications and variations of the present invention are possible without departing from the spirit and scope of the appended claims.

10, 10 '.. Scrubber system 20 .. Scrubber
30,130 .. Washing fluid supply device 40 .. Lamp
50. Photocatalyst 60. Treated water treatment section

Claims

A scrubber having a gas inlet through which a gas to be treated flows, a process gas outlet from which the introduced gas is treated, and a treated water outlet from which the treated water is treated;
A cleaning liquid supply device for supplying a cleaning liquid into the scrubber and treating the target gas introduced through the gas inlet to remove harmful substances;
A lamp capable of irradiating light within the scrubber to promote generation of highly reactive radicals from the cleaning liquid; And
And a photocatalyst disposed inside the scrubber to promote radical generation from the cleaning liquid,
Wherein the upper chamber and the lower chamber are sequentially provided with a photocatalyst, a lamp, and a jetting portion for jetting the cleaning liquid,
A partition wall for partitioning the inside of the scrubber into an upper chamber and a lower chamber, a barrel portion connected to the partition wall to allow gas introduced into the gas inlet to pass therethrough, A cover is provided to allow the cleaning liquid to flow down to the upper portion of the partition,
The cleaning liquid supply device includes:
An electrolytic bath for electrolyzing the process water in the lower chamber;
A first supply pump for pumping treatment water in the lower chamber to the electrolytic bath;
A first jetting part for jetting the cleaning liquid generated by electrolysis in the electrolytic bath at a top of a lamp and a photocatalyst in the lower chamber;
A recovery tank for recovering the cleaning liquid accumulated in the upper portion of the partition wall after use in the upper chamber;
A second jetting portion for jetting the cleaning liquid in the recovery tank from the upper portion of the lamp and the upper portion of the photocatalyst; And
And a second supply pump for pumping the cleaning liquid in the recovery tank to the second spray part.

delete

The method according to claim 1,
The photocatalyst is applied to a surface of any one of a metal plate, a glass fiber and a perforated plate provided inside the scrubber,
In the photocatalyst,
Wherein the at least one semiconductor component comprises at least one semiconductor component selected from tungsten, tungsten, silver, zinc oxide, tin oxide, iron oxide, platinum, palladium, molybdenum, boron and niobium and a transition metal.

The method according to claim 1,
Wherein the scrubbing liquid comprises sodium hypochlorite.

The lamp according to any one of claims 1, 3, and 4,
And an electrode lamp or an LED lamp capable of irradiating ultraviolet rays.

The method according to any one of claims 1, 3, and 4,
Wherein the photocatalyst, the lamp, and a jetting portion for jetting the cleaning liquid are sequentially disposed on the basis of the movement path of the target gas.

The method according to any one of claims 1, 3, and 4,
Further comprising a treatment water treatment unit for removing and circulating the foreign substances contained in the treatment water used for the target gas treatment in the scrubber.

The method according to any one of claims 1, 3, and 4,
Wherein the inner space of the scrubber is divided into two or more stages and the photocatalyst, the lamp, and the jetting portion for spraying the cleaning liquid are sequentially installed in each of the spaces partitioned by the plurality of stages or in a space of a specific stage A scrubber system.

delete

The method according to claim 1,
Further comprising a third injector for injecting a scrubbing liquid pumped into the electrolytic bath from the first supply pump downstream of the photocatalyst in the scrubber.