KR102543113B1 - Cyclone for dry granulation and separation of NOx and SOx - Google Patents

Abstract

The present invention relates to a cyclone for dry granulation and separate discharge of NO _x and SO _x , comprising: a cyclone body; a first inlet formed on the upper part of the cyclone body and through which exhaust gas containing NO _x and SO _x flows; a second inlet formed on the upper part of the cyclone body and through which gaseous ammonia flows; a third inlet formed on the upper part of the cyclone body and through which water vapor flows; a fourth inlet connected to the first inlet and into which ozone flows; A first outlet formed on the upper part of the cyclone body and through which purified exhaust gas is discharged; and a second outlet formed at a lower portion of the cyclone body and through which particles are discharged.

Description

Cyclone for dry granulation and separation of NOx and SOx

The present invention relates to a cyclone for dry granulation and separate discharge of NO _x and SO _x , and more specifically, mixing NO _x /SO _x present in exhaust gas with gaseous ammonia and water vapor in a dry manner at room temperature. It relates to a cyclone capable of granulating through and separating and discharging the generated particles.

Referring to FIG. 1, in facilities (power plants _, etc.) emitting air pollutants, selective catalytic reduction (SCR) is currently used to reduce NO _x , and flue gas desulfurization (FGD: Flue-Gas Desulfurization) is used. In addition, an electrostatic precipitator (ESP) is used to reduce particulate matter. In this way, separate devices are required to remove each contaminant.

Sources of particulate matter include various workplaces (semiconductor manufacturing facilities, etc.) and combustion facilities such as power plants. In addition, a large amount of NO _x and SO _x , which are substances that cause secondary generation of particulate matter, are emitted from these facilities. In order to treat flue gas discharged from a combustion facility, etc., as described above, a device for reducing NO _x , a device for reducing SO _x , and a device for removing particulate matter such as PM 2.5 must be separately installed.

An object of the present invention is to provide a cyclone capable of simultaneously reducing NO _x and SO _x through a single device without using separate treatment devices.

In order to achieve the above objects, the present invention: As a first embodiment: a cyclone body; a first inlet formed on the upper part of the cyclone body and through which exhaust gas containing NO _x and SO _x flows; a second inlet formed on the upper part of the cyclone body and through which gaseous ammonia flows; a third inlet formed on the upper part of the cyclone body and through which water vapor flows; a fourth inlet connected to the first inlet and into which ozone flows; A first outlet formed on the upper part of the cyclone body and through which purified exhaust gas is discharged; and a second outlet formed at a lower portion of the cyclone body and through which particles are discharged.

According to the first embodiment of the present invention, NO _x and SO _x are reacted with gaseous ammonia and water vapor to be particles in the form of salts, and the generated particles are separated from the exhaust gas inside the cyclone body and discharged through the second outlet, and the particles The separated flue gas may be discharged through the first outlet.

According to the first embodiment of the present invention, granulation can be performed dry at room temperature.

According to the first embodiment of the present invention, NO _x and SO _x are mixed with gaseous ammonia and water vapor inside the cyclone body, and may form a salt while rotating and moving from top to bottom.

According to the first embodiment of the present invention, the generated salt has viscosity and is generated inside the cyclone body and then moves downward, causing agglomeration between particles to increase the size of the particles.

According to the first aspect of the present invention, ozone is generated through the ozone generating device, and NO can be oxidized.

According to the first aspect of the present invention, the ozone generating device may be a dielectric barrier discharge plasma device.

Further, the present invention, as a second embodiment: a cyclone body; a first inlet formed on the upper part of the cyclone body and through which exhaust gas containing NO _x and SO _x flows; a second inlet connected to the first inlet and into which gaseous ammonia flows; a third inlet connected to the first inlet and into which water vapor flows; a fourth inlet connected to the first inlet and into which ozone flows; A first outlet formed on the upper part of the cyclone body and through which purified exhaust gas is discharged; and a second outlet formed at a lower portion of the cyclone body and through which particles are discharged.

According to the second embodiment of the present invention, NO _x and SO _x may be introduced into the cyclone body after reacting with gaseous ammonia and water vapor to be particles.

According to the second embodiment of the present invention, the size of the particles can be increased through aggregation after the particles are introduced into the cyclone body, and the reduction efficiency can be increased by increasing the size of the discharged particles.

According to the second embodiment of the present invention, the fourth inlet may be connected to the ozone generating device, and the ozone generating device may be connected to the fifth inlet through which air is introduced.

In addition, the present invention is an exhaust gas treatment method using a cyclone according to the first or second embodiment: mixing and reacting NO _x and SO _x with gaseous ammonia and water vapor to form particles in the form of salts; Separating the generated particles from exhaust gas and discharging them to the lower part; And it provides an exhaust gas treatment method comprising the step of discharging the exhaust gas from which the particles are separated to the top.

In the present invention, the stoichiometric ratio of gaseous ammonia may be 0.1 to 2.

In the present invention, the removal rate of NO ₂ is 10% or more, and the removal rate of SO ₂ may be 50% or more.

In the present invention, the water vapor content may be 0.01 to 5% by volume.

In the present invention, the concentration of SO ₂ may be 10 to 1500 ppm.

In the present invention, the particle size of the particles may be 0.1 to 10 μm, and the concentration of the particles may be 10 to 200 mg/m 3 .

The cyclone device according to the present invention is capable of simultaneously reducing NO _x and SO _x through a single device without using separate processing devices for reducing NO _x and SO _x . In addition, materials produced through dry granulation of NO _x and SO _x can be separated and discharged and usefully used as fertilizer.

1 shows a conventional SCR process and FGD process.
2 is a configuration diagram of a cyclone according to a first embodiment of the present invention.
3 is a configuration diagram of a cyclone according to a second embodiment of the present invention.
4 is a graph showing the effect of ammonia concentration in the present invention.
5 is a graph showing the effect of relative humidity in the present invention.
6 is a graph showing the effect of SO ₂ concentration in the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 2 , the cyclone 1 according to the first embodiment of the present invention includes a cyclone body 10, a first inlet 11, a second inlet 12, a third inlet 13, and a fourth inlet. (14), a first outlet 15, a second outlet 16, and the like.

The cyclone body 10 serves to remove the particles 17. To this end, the cyclone body 10 may be formed in a cylindrical shape so that the exhaust gas rotates inside, and the particles 17 move downward along the inner wall of the cyclone body 10 by gravity and centrifugal force while rotating together with the exhaust gas. It may be configured to gather on the floor after moving, and the lower part of the cyclone body 10 may have a conical tapered structure for collecting the particles 17 .

Exhaust gas supplied from the top of the cyclone body 10 may move from top to bottom and from the inner wall side to the center side while rotating. In order to maximize the cyclone movement of the exhaust gas, the cyclone body 10 may be provided with components such as vanes or blades for guiding the flow, and these components may have a helical shape or the like. It can have a certain direction.

The first inlet 11 is a place where flue gas including NO _x and SO _x flows, and is located on the upper part of the cyclone body 10 to increase the residence time and smooth and efficient particleization and collection. For example, it may be formed on the upper side of the side of the cyclone body 10.

The first inlet 11 may be disposed at a position of a first quadrant among quadrants that divide a circle into four evenly at 90-degree intervals based on the circular cross section of the cylindrical cyclone body 10, and The outer circumferential surface may be tangentially connected to the outer circumferential surface of the cyclone body 10 at a position of 0 degrees.

Exhaust gas may be exhaust gas discharged from combustion facilities such as various workplaces (semiconductor manufacturing facilities, etc.) and power plants. These facilities emit large amounts of _NOx and _SOx , which are sources of secondary generation of particulate matter.

The first inlet 11 may have a larger diameter than the other inlets 12, 13, and 14, for example, 1.5 to 2.5 times or 1.8 to 2.2 times that of the other inlets 12, 13, and 14. diameter can be

The second inlet 12 is a place where gaseous ammonia (NH ₃ ) is introduced, and is located on the upper part of the cyclone body 10, for example, for increasing the residence time and smooth and efficient particleization and collection. ) can be formed at the top of the side of.

The second inlet 12 may be disposed at the position of the second quadrant, and the outer circumferential surface of the second inlet 12 may be tangentially connected to the outer circumferential surface of the cyclone body 10 at an angle of 90 degrees. Accordingly, the second inlet 12 may be disposed while forming a 90 degree angle with the first inlet 11 . The second inlet 12 may be disposed at the same height or on the same plane as the first inlet 11 .

The third inlet 13 is a place where water vapor (H ₂ O) is introduced, and for increasing residence time and smooth and efficient particleization and collection, the upper part of the cyclone body 10, for example, the cyclone body 10 It can be formed at the top of the side of.

The third inlet 13 may be disposed at the position of the third quadrant, and the outer circumferential surface of the third inlet 13 may be tangentially connected to the outer circumferential surface of the cyclone body 10 at a position of 180 degrees. Accordingly, the third inlet 13 forms an angle of 90 degrees with the second inlet 12 and can be arranged symmetrically in parallel with the first inlet 11 while forming an angle of 180 degrees. The third inlet 13 may be disposed at the same height or on the same plane as the first inlet 11 and the second inlet 12 .

In this way, the first inlet 11, the second inlet 12, and the third inlet 13 are alternately arranged at 90 degree intervals like a pinwheel shape, so that the rotational flow of NO _x and SO _x and gaseous ammonia and water vapor is smooth. and can be formed efficiently, and accordingly, mixing and reaction, granulation, and collection of NO _x and SO _x and gaseous ammonia and water vapor can be performed smoothly and efficiently.

The fourth inlet 14 is a place where ozone (O ₃ ) is introduced, and may be directly connected to the first inlet 11, and before the exhaust gas flows into the cyclone body 10, ozone is mixed with NO in the exhaust gas. It can react to oxidize NO to NO ₂ and the like. The fourth inlet 14 may be orthogonally connected to the first inlet 11 from above in the height direction. Ozone may be generated through an ozone generating device, for example, the ozone generating device may be a dielectric barrier discharge (DBD) plasma device.

The first outlet 15 is a place where clean gas is discharged, and may be disposed lengthwise in the height direction at the upper center of the cyclone body 10, and the inside of the cyclone body 10 (for example, the cyclone body 10). It may extend from approximately the middle point in the height direction of the cyclone body 10 to the outside of the cyclone body 10 (through the upper end of the cyclone body and protruding to the outside). As such, the first outlet 15 extends deep inside the cyclone body 10, thereby preventing the particles 17 from being discharged through the first outlet 15.

The second outlet 16 is a place where the particles 17 are discharged, and may be formed at the center of the lower part of the cyclone body 10, specifically at the lower end of the lower part having a tapered structure.

According to the first embodiment, NO _x and SO _x are reacted with gaseous ammonia and water vapor to be particles in the form of salts, and the generated particles 17 are separated from the flue gas inside the cyclone body 10, and the second outlet 16 ), and the exhaust gas from which the particles 17 are separated may be discharged through the first outlet 15.

In this way, salt (particulate matter) can be formed by injecting ammonia gas and water vapor into exhaust gas containing NO _x and SO _x generated by combustion, and NO _x /SO x and NO x /SO _x and It may have a form in which exhaust gases from which their salts are removed are discharged.

Granulation may be performed dry at room temperature. Room temperature may mean approximately 20 ± 5 ° C, and dry may mean a state in which there is no or almost no liquid such as water (eg, water content of 5, 3, or 1% by weight or less). Since granulation is performed in a dry manner at room temperature, granulation can be efficiently and smoothly performed while reducing costs due to temperature control.

According to the first embodiment, NO _x and SO _x are mixed with gaseous ammonia and water vapor inside the cyclone body 10, and may form salt while rotating and moving from top to bottom. In this way, NO _x /SO _x and ammonia / water vapor are mixed inside the cyclone, and may form a salt while rotating and moving from the top to the bottom. The rotating flow can be attributed to the arrangement structure of the inlets 11, 12 and 13 as described above.

According to the first embodiment, the generated salt (particles) has viscosity and is generated inside the cyclone body 10, and then agglomeration occurs between the particles 17 while moving downward, so that the size of the particles 17 may increase. there is. As shown in FIG. 2 , the particle 17 gradually increases in size as it moves downward while rotating after being formed at the top, and thus the collection efficiency may increase.

In addition, after generating ozone through an ozone generator such as DBD plasma, it is possible to oxidize NO by injecting it into exhaust gas containing NO _x /SO _x . However, even if ozone is added to the NO _x /SO _x mixed gas, ozone oxidizes only with NO in NO _x .

Referring to FIG. 3 , the cyclone 2 according to the second embodiment of the present invention includes a cyclone body 20, a first inlet 21, a second inlet 22, a third inlet 23, and a fourth inlet. (24), a first outlet 25, a second outlet 26, an ozone generator 28, a fifth inlet 29, and the like. The cyclone 2 according to the second embodiment is different from the cyclone 1 according to the first embodiment in the following two respects, and the rest of the configuration may be the same as the cyclone 1 according to the first embodiment.

First, in the arrangement of the inlet, unlike the cyclone 1 according to the first embodiment of FIG. 2 in which the second inlet 12 and the third inlet 13 are independently connected to the cyclone body 10, in FIG. In the cyclone 2 according to the second embodiment, the second inlet 22 and the third inlet 23 may be directly connected to the first inlet 21 without being independently connected to the cyclone body 20.

Second, in terms of the time and location of granulation, after the reactants NO _x and SO _x , gaseous ammonia, and water vapor are introduced into the cyclone body 10, granulation occurs, and the granulation progresses in the cyclone body 10. Unlike the cyclone 1 according to _the first embodiment of Fig _. 2, in the cyclone 2 according to the second embodiment of FIG. Granulation occurs before the particle formation occurs, and the granulation may proceed within the first inlet 21 .

In this way, according to the second embodiment, NO _x and SO _x may be introduced into the cyclone body 20 after reacting with gaseous ammonia and water vapor to be particles. That is, granulation may already proceed in the first inlet 21 before being introduced into the cyclone body 20, and particles 27 that have already been granulated may directly flow into the cyclone body 20.

According to the second embodiment, compared to the first embodiment, the size of the particles 27 can be increased through aggregation after the particles 27 are introduced into the cyclone body 20, and the discharged particles 27 ) can increase the abatement efficiency.

According to the second embodiment, the fourth inlet 24 may be connected to an ozone generator 28 such as DBD plasma, and the ozone generator 28 may be connected to the fifth inlet 29 through which air is introduced. . The ozone generating device 28 can generate ozone from air. In the case of the injection sequence, ozone may be injected into the flue-gas first, followed by ammonia and water vapour. Accordingly, NO in the exhaust gas first reacts with ozone to undergo gas phase oxidation, and then the gas is converted into particles (granularization) at the time of injection of ammonia and water vapor.

In addition, the present invention is an exhaust gas treatment method using a cyclone according to the first or second embodiment: mixing and reacting NO _x and SO _x with gaseous ammonia and water vapor to form particles in the form of salts; Separating the generated particles from exhaust gas and discharging them to the lower part; And it provides an exhaust gas treatment method comprising the step of discharging the exhaust gas from which the particles are separated to the top.

The granulation principle and chemical reaction formula are as follows. Specifically, as follows, an oxidation reaction by ozone, a reaction by water vapor, an ammonium salt production reaction by ammonia, and a _NOx reduction reaction by ammonium sulfate salt may occur.

The stoichiometric ratio of gaseous ammonia may be 0.1 to 2, 0.25 to 1.75, 0.5 to 1.5, 0.5 to 1, 1 to 1.5, or 1.25 to 1.75. Here, the stoichiometric ratio may mean a ratio of (actually injected ammonia amount) / (theoretically required ammonia amount).

The NO ₂ removal rate may be 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, or 70% or more. The removal rate of SO ₂ may be 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 93% or more.

Figure 4 shows the effect of ammonia concentration on granulation, showing the SO _x and NO _x reduction efficiency according to the NH ₃ stoichiometric ratio. The SO _x and NO _x removal efficiencies in FIG. 4 can be calculated from the following equations. Here, η represents the removal efficiency, and C represents the concentration at the inlet and outlet.

은 몰 유속을 나타내고, λ는 양론 비율을 나타낸다.The stoichiometric ratio can be calculated from the following formula. here,

represents the molar flow rate, and λ represents the stoichiometric ratio.

According to FIG. 4, as the NH ₃ stoichiometric ratio increases, SO _x and NO _x reduction efficiencies increase. Specifically, in the range of 0.5 to 1 stoichiometric ratio, a steep increase in efficiency was observed with an increase. Further, in the range of stoichiometric ratio of 1 to 1.5, a gradual increase in efficiency was observed with an increase. The reason for this result is that NH ₃ slip occurred rapidly from the stoichiometric ratio of 1. NH ₃ slip means that residual ammonia is discharged into the atmosphere after the granulation reaction. In the case of SO ₂ , when the stoichiometric ratio was 1.5, the highest removal efficiency of 93.4% was exhibited. In the case of NO ₂ , when the stoichiometric ratio was 1.5, the highest removal efficiency was 70.3%.

The water vapor content may be 0.01 to 5 vol%, 0.05 to 4 vol%, 0.1 to 3 vol%, 1 to 3 vol%, or 2 to 3 vol%.

5 shows the effect of relative humidity on granulation, and shows SO _x and NO _x reduction efficiency according to relative humidity.

In the case of SO ₂ , the higher the relative humidity, the higher the removal efficiency. When the relative humidity was 95%, the maximum efficiency was 90%. This is because, as the relative humidity is higher, there is an excess of H ₂ O to react with SO ₂ , as in the following reaction.

In the case of NO _x , it was hardly affected by relative humidity. This is because the main mechanism for NO _x removal is removal by ammonium sulphate, not by ammonium nitrate production. Therefore, there was no effect on H ₂ O.

The concentration of SO ₂ may be 10 to 1500 ppm, 50 to 1300 ppm, 100 to 1200 ppm, 200 to 1100 ppm, 300 to 1000 ppm, or 600 to 900 ppm.

The particle size of the particles may be 0.1 to 10 μm, 0.15 to 9 μm, 0.2 to 8 μm, 0.25 to 7 μm, 0.3 to 6 μm, 0.35 to 5 μm, or 0.4 to 4 μm. The node diameter of the particles may be 1.5±0.2 μm.

The concentration of the particles is 10 to 200 mg/m3, 20 to 190 mg/m3, 30 to 180 mg/m3, 40 to 170 mg/m3, 50 to 160 mg/m3, 60 to 150 mg/m3, 70 to 140 mg /m3, 80 to 135 mg/m3, 90 to 130 mg/m3, or 100 to 125 mg/m3.

6 shows the particle size distribution and concentration of ammonium generating particles according to SO ₂ concentration as a result of particleization. APS (Aerodynamic Particle Sizer) and SMPS (Scanning Mobility Particle Sizer) were used as particle size analyzers. Ammonium salt (1.59 g/cm 3 ) particles having a mode particle diameter of about 1.5 μm were produced by NH ₃ injection. When the SO ₂ concentration was increased, the concentration of particles increased. Also, even if the SO ₂ concentration was increased, the mode particle size hardly changed.

1, 2: Cyclone
10, 20: cyclone body
11, 21: first inlet
12, 22: second inlet
13, 23: 3rd inlet
14, 24: 4th inlet
15, 25: first outlet
16, 26: second outlet
17, 27: particle
28: ozone generator
29: 5th inlet

Claims (17)

cyclone body;
a first inlet formed on the upper part of the cyclone body and through which exhaust gas containing NO _x and SO _x flows;
a second inlet formed on the upper part of the cyclone body and through which gaseous ammonia flows;
a third inlet formed on the upper part of the cyclone body and through which water vapor flows;
a fourth inlet connected to the first inlet and into which ozone flows;
A first outlet formed on the upper part of the cyclone body and through which purified exhaust gas is discharged; and
It is formed in the lower part of the cyclone body and includes a second outlet through which particles are discharged,
NO _x and SO _x react with gaseous ammonia and water vapor to form particles in the form of salts, and the generated particles are separated from the exhaust gas inside the cyclone body and discharged through the second outlet, and the exhaust gas separated from the particles is discharged through the first outlet. become,
Granulation is done dry at room temperature,
Dry is a state in which the water content is 5% by weight or less,
The stoichiometric ratio of gaseous ammonia is 0.1 to 2,
The content of water vapor is 0.01 to 5% by volume,
A cyclone having a particle size of 0.1 to 10 μm and a particle concentration of 10 to 200 mg/m 3 . delete delete According to claim 1,
NO _x and SO _x are mixed with gaseous ammonia and water vapor inside the cyclone body, and a cyclone that forms salt while rotating and moving from top to bottom. According to claim 4,
The generated salt has viscosity and is created inside the cyclone body, and then moves to the bottom of the cyclone, causing agglomeration between particles to increase the size of the particles. According to claim 1,
Ozone is generated through an ozone generator, a cyclone that oxidizes NO. According to claim 6,
The ozone generator is a cyclone, which is a dielectric barrier discharge plasma device. cyclone body;
a first inlet formed on the upper part of the cyclone body and through which exhaust gas containing NO _x and SO _x flows;
a second inlet connected to the first inlet and into which gaseous ammonia flows;
a third inlet connected to the first inlet and into which water vapor flows;
a fourth inlet connected to the first inlet and into which ozone flows;
A first outlet formed on the upper part of the cyclone body and through which purified exhaust gas is discharged; and
It is formed in the lower part of the cyclone body and includes a second outlet through which particles are discharged,
NO _x and SO _x react with gaseous ammonia and water vapor to form particles in the form of salts, and the generated particles are separated from the exhaust gas inside the cyclone body and discharged through the second outlet, and the exhaust gas separated from the particles is discharged through the first outlet. become,
Granulation is done dry at room temperature,
Dry is a state in which the water content is 5% by weight or less,
The stoichiometric ratio of gaseous ammonia is 0.1 to 2,
The content of water vapor is 0.01 to 5% by volume,
A cyclone having a particle size of 0.1 to 10 μm and a particle concentration of 10 to 200 mg/m 3 . According to claim 8,
NO _x and SO _x react with gaseous ammonia and water vapor to form particles, and then flow into the cyclone body. According to claim 9,
A cyclone capable of increasing the size of particles through aggregation after particles flow into the cyclone body, and increasing the reduction efficiency by increasing the size of discharged particles. According to claim 8,
The fourth inlet is connected to the ozone generating device, and the ozone generating device is connected to the fifth inlet through which air is introduced. An exhaust gas treatment method using a cyclone according to claim 1 or 8:
mixing and reacting NO _x and SO _x with gaseous ammonia and water vapor to form particles in the form of salts;
Separating the generated particles from exhaust gas and discharging them to the lower part; and
Exhaust gas treatment method comprising the step of discharging the exhaust gas from which the particles are separated to the top. delete According to claim 12,
An exhaust gas treatment method in which the removal rate of NO ₂ is 10% or more and the removal rate of SO ₂ is 50% or more. delete According to claim 12,
The concentration of SO ₂ is 10 to 1500 ppm flue gas treatment method. delete

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