KR102073342B1 - Apparatus for generating secondary inorganic aerosol - Google Patents

Abstract

The present invention provides a supply for supplying the reactants required for the reaction; A reaction unit generating a product including secondary fine dust from a reactant supplied including a reactor into which mineral particles are injected and a UV light source; And a collecting unit collecting the products to analyze the product discharged from the reactor. The present invention relates to a secondary fine dust generating device that generates secondary fine dust from primary contaminants. By analyzing the composition of the product produced when the reaction by varying the various changes can provide a secondary fine dust generating apparatus capable of analyzing the secondary fine dust generating mechanism.

Description

Apparatus for generating secondary inorganic aerosol}

The present invention relates to a secondary fine dust generating apparatus, and more particularly to a secondary fine dust generating apparatus that can be used in the study of the secondary fine dust generating reaction mechanism.

Here, background art is provided with respect to the present disclosure, and these do not necessarily mean known art.

Dust is a particulate matter floating or scattering in the air. It is often generated when burning fossil fuels such as coal and petroleum or from exhaust gases from factories and automobiles. Dust is divided into Total Dust (TSP), which is 50μm or less, and Particulate Matter (PM) with very small particle size.

Fine dust is divided into fine dust (PM10) smaller than 10 μm in diameter and fine dust (PM2.5) smaller than 2.5 μm in diameter. In addition, fine dust comes from solid sources such as chimneys as solid dust (primary occurrence), and from sources, gaseous substances become fine dust by chemical reaction with other substances in the air (secondary generation). Can be divided.

Fine dust is a Group 1 carcinogen classified by the World Health Organization (WHO), and when fine dust accumulates in the bronchus, bacteria can easily penetrate, increasing the incidence of infectious diseases, and sulfur dioxide in the air. Fine dust containing lots of SO ₂ ) or nitrogen dioxide (NO ₂ ) can cause acid rain to acidify soil and water, and can cause soil degradation, ecosystem damage, damage to forest trees and other vegetation. Exposure to fine dust in the production process, such as the automotive industry, can increase the defective rate and damage the malfunction.

In the case of thermal power plants, the amount of primary fine dust (direct emissions) is not large, but the generation of secondary fine dust (indirect emissions) by NOx and SOx may be a problem. In the past, the research on the device that blocks, collects and removes the generated fine dust has been mainly conducted, and related to the fine dust generating device for the research related to the secondary fine dust generation reaction by NOx and SOx emitted from the thermal power plant chimney There is no research.

1. Korea Patent Registration No. 10-1553136 (2015-09-08) 2. Korea Patent Registration No. 10-1569721 (2015-11-11)

The present invention to solve the above problems is to provide a secondary fine dust generating apparatus that can be used in the study of the secondary fine dust generation reaction mechanism.

However, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention provides a supply for supplying the reactants required for the reaction; A reaction unit generating a product including secondary fine dust from a reactant supplied including a reactor into which mineral particles are injected and a UV light source; And a collecting unit collecting the products to analyze the product discharged from the reactor. The apparatus includes a secondary fine dust generating device that generates secondary fine dust from primary pollutants.

In addition, the supply unit includes SOx supply means, NOx supply means and N ₂ supply means for supplying SOx, NOx and N ₂ to the reactor.

The N ₂ supply means further includes means for allowing N ₂ to pass through H ₂ O in the line fed to the reactor.

The supply unit further includes a steam supply means for supplying steam to the reactor.

In addition, the supply unit further includes a mixing means in a line where SOx and NOx are supplied to be supplied to the reactor 21 in a state where SOx and NOx are mixed.

In addition, the mineral particles include any one or more particles selected from the group consisting of Al ₂ O ₃ , CaO, MgO, Fe ₂ O ₃ , SiO ₂ , TiO ₂ and ZnO.

In addition, the reactor is provided with a stirrer at the bottom, it is provided with a translucent material.

The collector is also a filter device which is a means for filtering the solid components contained in the product and for passing the gas components.

In addition, the rear end of the collecting unit further comprises a post-processing of the components passed through the collecting unit and discharged to the atmosphere.

In addition, by analyzing the composition of the product generated when the reaction conditions by changing the supply and the reaction unit it is possible to analyze the secondary fine dust generation mechanism.

The present invention can provide a secondary fine dust generating apparatus capable of analyzing the secondary fine dust generating mechanism by analyzing the composition of the product generated when the reaction reacts and the reaction part to vary the conditions of the supplied product.

In addition, it can be assumed that the reaction mechanism for generating NO ₃ ⁻ and SO ₄ ^2- from NO ₂ (g) and SO ₂ (g) in various stages, and the present invention can be assumed by varying the reaction conditions. By comparing and analyzing whether the analysis result is consistent with the mechanism, it is possible to provide a secondary fine dust generating apparatus that can be used to identify the generation mechanism of the secondary fine dust.

1 is a block diagram of a secondary fine dust generating device according to an embodiment of the present invention.
Figure 2 shows the SEM image and EDS analysis results of the mineral particles before the reaction according to an embodiment of the present invention.
Figure 3 shows the SEM image and EDS analysis results of the mineral particles after the reaction according to an embodiment of the present invention.
Figure 4 shows the result of measuring the S content through the EDS analysis of the mineral particles after the reaction according to an embodiment of the present invention.
Figure 5 shows an SEM image of the filter paper before the reaction according to an embodiment of the present invention.
Figure 6 shows the SEM image of the filter paper after the reaction according to an embodiment of the present invention.
Figure 7 shows the result of measuring the S content through the EDS analysis of the filtered component after the reaction according to an embodiment of the present invention.
Figure 8 shows the results of measuring the particle size before and after the reaction of the mineral particles according to an embodiment of the present invention.

Prior to describing the present invention in detail below, it is understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention, which is limited only by the scope of the appended claims. shall. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise indicated.

Throughout this specification and claims, unless otherwise indicated, the termcomprise, comprises, and configure means to include the referenced article, step, or group of articles, and step, and any other article It is not meant to exclude a stage or group of things or a group of stages.

On the other hand, various embodiments of the present invention can be combined with any other embodiment unless clearly indicated to the contrary. Any feature indicated as particularly preferred or advantageous may be combined with any other feature and features indicated as preferred or advantageous. Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention and the effects thereof.

Secondary fine dust generating device 1 according to an embodiment of the present invention is sulfuric acid from sulfur oxides (sulfur oxides, SOx), nitrogen oxides (nitrogen oxide, NOx) as the primary pollutants under light irradiation conditions using minerals (sulfuric acid), nitric acid (nitric acid) aerosol to produce a secondary fine dust by converting into a sulfate (sulfate), nitrate (nitrate), a supply unit for supplying the reactants necessary for the reaction (10), mineral particles To collect the products to analyze the product discharged from the reactor 20 and the reactor 20 to produce a product containing secondary fine dust from the reactant supplied, including the reactor 21 and the UV light source 22 is added The unit 30 is included.

The supply unit 10 includes the SOx supply unit 11, the NOx supply unit 12, and the N ₂ supply unit 13 to supply SOx, NOx, and N ₂ to the reactor 21. The supply means may further include a mass flow controller (MFC), respectively, to adjust the flow rates of SOx, NOx and N ₂ supplied to the reactor. The supply unit 10 may be performed in a batch process by supplying and blocking a predetermined amount of the reactants, and may be performed in a continuous process by continuously supplying the reactants.

SOx supply means 11 and NOx supply means 12 is a means for supplying the sulfur oxides and nitrogen oxides in the gaseous state to the reactor 21 serves to supply the primary pollutant for conversion into secondary fine dust. .

The N ₂ supply means 13 serves to supply gaseous nitrogen to the reactor 21 to remove contaminants in the reactor and to transfer moisture and other substances before the reaction. The N ₂ supply means 13 allows N ₂ to pass through H ₂ O in the line supplied to the reactor 21 to meet the humidity conditions in the atmospheric environment.

In addition, the supply unit 10 further includes a steam supply means 14, and by supplying steam to the reactor 21, it is possible to meet the humidity conditions of the exhaust gas discharged from the power plant chimney, the humidity according to the change in the atmospheric environment Conditions can be controlled by controlling the steam supply.

In addition, the supply unit 10 may further include a mixing means 15 in a line to which SOx and NOx are supplied to be supplied to the reactor 21 in a state where SOx and NOx are mixed. When SOx and NOx are supplied in a mixed state than when they are supplied in separate lines, dispersibility is improved to increase the reaction yield.

By the configuration of the supply unit 10 as described above it is possible to control the reaction method, composition (component and content), flow rate and the like.

The reaction unit 20 includes a reactor 21 and a UV light source 22 to which mineral particles are added to generate a product including secondary fine dust from the supplied reactant, so that gaseous reactants are solid particles in a solid state. Allow for heterogeneous reactions to occur.

The reactor 21 is provided with an inlet 23 so that mineral particles can be introduced therein so that the sulfur oxide supplied from the surface of the mineral particles is converted into sulfate. At this time, the supplied nitrogen oxide coexists with the mineral particles to enhance the oxygen activity in the molecular state to act as an oxidation catalyst, so that the sulfur oxides are easily converted into sulfates on the surface of the mineral particles to generate secondary fine dust. .

The mineral particles include any one or more particles selected from the group consisting of Al ₂ O ₃ , CaO, MgO, Fe ₂ O ₃ , SiO ₂ , TiO ₂ and ZnO. For coal ash, SiO ₂ 30-35 wt%, Al ₂ O ₃ 15-20 wt%, CaO 15-20 wt%, Fe ₂ O ₃ 5-10 wt%, TiO ₂ 0.5-1.0 wt%, MgO 3 ~ The composition of 7 wt%, K ₂ O 0.5-3 wt% and P ₂ O ₅ 0.1-0.5 wt% can be supplied using coal-fired fly ash (coal ash) as mineral particles. Secondary fine dust may be generated by adjusting the type and physical properties (particle size, specific surface area, etc.) of mineral particles to be introduced.

The mineral particles may be temporarily injected into the reactor, but may be continuously supplied by injection.

In addition, the reactor 21 is provided with a stirrer at the bottom so that the materials inside the reactor are evenly mixed and dispersed. Secondary fine dust may be generated by adjusting the stirring speed or the stirring form.

The UV light source 22 provides energy required for generating secondary fine dust. The UV light source 22 is provided outside the reactor 21 to operate to generate secondary fine dust by adjusting the intensity, irradiation pattern and reaction time of the light source. have.

In addition, the reactor 21 is provided with a light-transmissive material to allow the UV light irradiated from the outside of the reactor to be introduced into the reactor, and to visually observe the reaction that the secondary fine dust is generated in the reactor. In addition, the reactor 21 is equipped with a temperature and humidity sensor to measure the change in temperature and humidity during the secondary fine dust generation reaction in real time.

When the UV light source 22 is operated while the reactant is supplied inside the reactor 21, sulfates such as SO ₄ ^2- and nitrates such as NO ³ − are generated from sulfur oxides and nitrogen oxides on the surface of the mineral particles. At this time, by changing the conditions of the supply unit and the reaction unit in various ways, it is possible to obtain secondary fine dust generation results according to the reaction conditions.

The collection unit 30 separates the gas product and the solid product by passing the product produced in the reactor 21. For example, the collection unit 30 filters a solid component such as sulfate, nitrate, and mineral particles contained in the product as a filter device and passes gas components such as supplied NOx, SOx, and N ₂ .

The component passing through the collection unit 30 is discharged to the atmosphere through the discharge unit 40 to be described later, the component filtered by the collection unit 30 is used for component analysis through the analysis means. As an analysis means, various analytical devices such as scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), ion chromatograph (IC), and particle size analyzer (PSA) may be used.

Secondary fine dust generating apparatus 1 according to an embodiment of the present invention further comprises a discharge unit 40 at the rear end of the collecting unit 30 after the post-treatment of the components passed through the collecting unit 30 Release to air. For example, the discharge unit 40 may be provided with a basic solution such as NaOH and react with and absorb SOx and NOx, which are acid gases, of the gas product passing through the collection unit 30 to discharge the remaining components.

1 is a block diagram of a secondary fine dust generating device according to an embodiment of the present invention. The mechanism of reaction to produce NO ₃ ⁻ and SO ₄ ^2- from NO ₂ (g) and SO ₂ (g) can be assumed in several stages, and the reaction conditions are varied to match the hypothesized reaction mechanism. The results of the analysis can be compared and analyzed to find the mechanism for generating secondary fine dust.

As an example, the generation mechanism of the secondary fine dust can be assumed as follows.

① NO ₂ (g) and SO ₂ (g) absorbs on particle surface formed NO ₂ (ads) and SO ₃ ^2- .

② NO ₂ (ads) dimerizes to N ₂ O ₄ (ads) in the presence of O ₂ and S (IV).

③ N ₂ O ₄ (ads) oxidize the SO ₃ ^2- to SO ₄ ^2- , itself converted into NO ^2- .

④ NO ^2- converted into NO ^3- in the presence of NO ₂ (g).

Assuming the reaction mechanism as described above, by analyzing the composition of the product produced when the composition of the reactant is changed it can be determined whether it is consistent with the mechanism.

In the following Examples and Experimental Examples show some examples of the analysis after generating secondary fine dust by adjusting some of the reaction conditions that can be controlled using the apparatus of the present invention.

Example

Secondary fine dust was produced by controlling the conditions shown in Table 1 using the apparatus of the present invention. The concentrations of NO ₂ and SO ₂ were 50 ppm, and N ₂ was 99.99%. The UV light source was used 20W UV lamp, the mineral particles were dried at 105 ℃ for 24 hours and 500mg quantification was used.

Flow rate (cm ³ / min) Mineral particles reaction
Hours (h) NO ₂ SO ₂ N ₂ Example 1 100 100 - Al ₂ O ₃ 2 Example 2 100 100 200 Al ₂ O ₃ 2 Example 3 100 100 - CaO 2 Example 4 100 100 - MgO 2 Example 5 100 100 - TiO ₂ 2 Example 6 100 100 - SiO ₂ 2 Example 7 100 100 - Fe ₂ O ₃ 2 Example 8 100 100 - ZnO 2

After generating secondary fine dust under the above conditions, the filtered mineral particles and the components filtered on the filter paper inserted into the filter device were analyzed as in the following experimental example.

Experimental Example

(1) Ion Chromatograph

The content of sulfate (SO ₄ ^2- ) and nitrate (NO ₃ ⁻ ) in the product according to the example was measured using an ion chromatograph apparatus, and the results are shown in Table 2 below. As shown in Table 2, it can be seen that the amount of sulfates and nitrates produced according to the type of minerals and the concentration of the atmosphere gas is different.

SO ₄ ^2- (μg) NO ₃ ^- (μg) Example 1 25.58 1180.52 Example 2 28.24 984.90 Example 3 8.98 87.27 Example 4 45.08 321.02 Example 5 17.53 14.73 Example 6 7.68 19.09 Example 7 11.65 24.88 Example 8 24.38 28.89

(2) SEM-EDS and S content

In order to identify sulfates and nitrates formed by the reaction between the mineral particles, sulfur oxides and nitrogen oxides, the mineral particles before and after the reaction were carried out through the SEM-EDS device for Examples 1, 3, 5 and 7. Analyzed. Figure 2 shows the SEM image and EDS analysis results of the mineral particles before the reaction, Figure 3 shows the SEM image and EDS analysis results of the mineral particles after the reaction. In addition, the S content was measured through the EDS analysis of the mineral particles after the reaction, and is shown in FIG. 4. As shown in FIG. 4, the S component was detected in the mineral particle sample after the reaction, and it was confirmed that a chemical reaction occurred between the mineral particle and the contaminants (NO ₂ and SO ₂ ), and the S content of the mineral particle of Example 1 was increased. It can be seen that it is relatively high.

In addition, the filtered components were analyzed by SEM-EDS equipment. 5 shows an SEM image of the filter paper before the reaction, and FIG. 6 shows an SEM image of the filter paper after the reaction. In addition, the S content was measured by EDS analysis of the filtered component after the reaction, and is shown in FIG. 7. As shown in FIG. 6, it can be seen that particles were collected in the filter paper in Al ₂ O ₃ , CaO, and Fe ₂ O ₃ experiments except for TiO ₂ . In addition, as shown in Figure 7, it can be seen that the S component was measured in the EDS analysis of Al ₂ O ₃ , CaO.

To check that by the analysis result of chemical reaction between the mineral particles and pollutants _{(NO 2, SO 2),} Al 2 O 3, CaO, TiO 2, Fe 2 O 3 of the Al ₂ in O ₃ most It was confirmed that a positive S was detected. This shows that the mineral was converted into a sulfur-containing material through the reaction.

(3) PSA

The particle size before and after the reaction of the mineral particles of Example 2 and Example 3 was measured and shown in FIG. 8. As shown in FIG. 8, it can be seen that the smaller particles increased after the mineral particles reacted with SOx and NOx. From this, the primary particles reacted in the air, and the secondary particles of the smaller size were more dangerous to the human body. It can be seen that dust is produced.

The features, structures, effects, and the like illustrated in the above-described embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be interpreted that the contents related to such a combination and modification are included in the scope of the present invention.

1: 2nd fine dust generator
10: supply
11: SO ₂ supply
12: NO ₂ supply means
13: N ₂ supply means
14: Steam supply
15: mixing means
20: reaction part
21: reactor
22: UV light source
23: inlet
30: collection
40: discharge part

Claims (10)

A supply unit for supplying at least one or more reactants from SOx and NOx to the reactor;
A reaction unit including a reactor into which the reactant and the mineral particles are injected and a UV light source irradiating UV into the reactor; And
A secondary fine dust generating device for generating secondary fine dust, comprising: a collecting unit for collecting products for analyzing the product discharged from the reactor,
The reaction unit generates secondary fine dust under the UV light source irradiation, the mineral particles react with the reactants to form secondary fine dust in the form of at least one of sulfate and nitrate formed on the surface of the mineral particles.
The method of claim 1,
The supply unit is a secondary fine dust generating device including SOx supply means, NOx supply means and N ₂ supply means for supplying SOx, NOx and N ₂ to the reactor.
The method of claim 2,
The N ₂ supply means further comprises a means for allowing the N ₂ to pass through H ₂ O in the line supplied to the reactor.
The method of claim 1,
The supply unit further comprises a steam (steam) supply means for supplying steam to the reactor.
The method of claim 2,
The supply unit further comprises a mixing means in the line for supplying SOx and NOx secondary secondary dust generating device to be supplied to the reactor in a state of mixing SOx and NOx.
The method of claim 1,
The mineral particles are secondary fine dust generating device comprising any one or more particles selected from the group consisting of Al ₂ O ₃ , CaO, MgO, Fe ₂ O ₃ , SiO ₂ , TiO ₂ and ZnO.
The method of claim 1,
The reactor is provided with a stirrer at the bottom, secondary fine dust generating device provided with a light-transmissive material.
The method of claim 1,
And the collecting unit is a filter device that filters the solid component contained in the product and passes the gas component.
The method of claim 1,
Further comprising a discharge unit at the rear end of the collecting unit, the secondary fine dust generating device for post-processing the components passed through the collecting unit and discharged to the atmosphere.
The method of claim 1,
Secondary dust generation apparatus capable of analyzing the secondary fine dust generation mechanism by analyzing the composition of the product generated when the reaction conditions by changing the supply and the reaction unit.

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