KR20210031083A - Apparatus for removing carbon particulate material through addition of nitrogen oxide - Google Patents

Abstract

The present invention discloses a carbon particulate matter removal system through the addition of nitrogen oxides. According to the present invention, an atmospheric low-temperature plasma reactor for supplying ozone generated through an oxidation reaction of oxygen or air; And _{a combustion reactor that is filled with a perovskite catalyst having an ABO 3} or A ₂ BO ₄ structure and uses ozone and nitrogen oxide supplied to the atmospheric low-temperature plasma reactor to burn the carbon particulate matter. A system is provided.

Description

Apparatus for removing carbon particulate material through addition of nitrogen oxide

The present invention relates to a system for removing carbon particulate matter through the addition of nitrogen oxides.

Nowadays, environmental health problems related to fine dust are getting serious, and efforts are being made to reduce the emission of fine dust from various sources of fine dust.

Fine dust contains various chemical components including hydrate particles derived from nitrogen oxides and sulfur oxides, but a significant portion of the fine dust is composed of carbon particulate matter. Carbon particulate matter is discharged from fixed sources such as thermal power plants, steel mills, and chemical plants that use fossil fuels as energy sources, and from mobile sources such as internal combustion engine vehicles.

Carbon particulate matter is generated by incomplete combustion reactions that accompany the combustion of various types of fossil fuels to obtain heat energy required for the operation of the process. Efforts such as introducing an oxygen combustion reaction have been generally attempted.

However, even if such process improvement is made, the generation and discharge of some carbon particulate matter is inevitable in many cases, and a post-treatment method in which carbon particulate matter is removed by installing a catalytic combustion reactor in the exhaust gas pipeline is often introduced. .

For low-temperature combustion of carbon particulate matter, a method of introducing ozone as an oxidizing agent can be considered as follows.

[Scheme 1]

O ₃ (g) + C(s) → CO ₂ (g) + 0.5 O ₂ (g)

The above-described reaction is theoretically known to burn carbon particulate matter from room temperature, and the combustion rate increases as the temperature increases, and then decreases when ozone begins to pyrolyze due to the increased temperature. The combustion reaction is terminated when it reaches 300~350℃ where ozone is completely decomposed.

Therefore, since the combustion reaction of carbon particulate matter by ozone is limited by temperature, it is necessary to devise a method for improving the combustion reaction rate under a given reaction temperature condition.

Korean Patent Registration 10-1863940

In order to solve the above problems of the prior art, the present invention is to propose a carbon particulate matter removal system through the addition of nitrogen monoxide capable of improving the combustion reaction rate of carbon particulate matter by ozone even under low temperature conditions.

In order to achieve the above object, according to an embodiment of the present invention, there is provided a system for removing particulate matter by adding nitrogen oxides, comprising: an atmospheric low-temperature plasma reactor supplying ozone generated through an oxidation reaction of oxygen or air; And _{a combustion reactor that is filled with a perovskite catalyst having an ABO 3} or A ₂ BO ₄ structure and uses ozone and nitrogen oxide supplied to the atmospheric low-temperature plasma reactor to burn the carbon particulate matter. A system is provided.

It is disposed at the front end of the combustion reactor, nitrogen monoxide and ozone are supplied at a stoichiometric ratio of 1:1, and may further include a mixer for converting and discharging nitrogen monoxide into nitrogen dioxide.

Nitrogen oxide supplied to the combustion reactor may have a concentration range of 0.1 to 0.2 relative to the ozone.

The low-temperature combustion of the carbon particulate material may be performed within a range of 100 to 300°C.

The atmospheric low-temperature plasma reactor may be a dielectric barrier discharge (DBD) reactor.

According to another aspect of the present invention, there is provided a system for removing carbon particulate matter through the addition of nitrogen oxides, comprising: a mixer in which nitrogen monoxide and ozone are supplied at a stoichiometric ratio of 1:1 to convert nitrogen monoxide into nitrogen dioxide and discharge it; And there is provided a carbon particulate matter removal system comprising a combustion reactor that is filled with a perovskite catalyst having an _{ABO 3} or A ₂ BO _{4 structure, and burns the carbon particulate matter using ozone and nitrogen dioxide converted in the mixer.} .

According to the present invention, it is possible to promote the combustion reaction of carbon particulate matter under low-temperature conditions and supply of ozone through the addition of nitrogen oxide.

1 is a diagram showing a system for removing carbon particulate matter through the addition of nitrogen oxides according to an embodiment of the present invention.
Figure 2 shows the results of the thermal decomposition experiment of ozone, the reactor: O ₂ 10%, O ₃ 2500 ppm, N ₂ balance. 300 cc/min; It shows the change in the concentration of ozone at a temperature rise rate of 3℃/min.
3 is a diagram showing the configuration of a DBD plasma reactor for generating ozone to be used for low-temperature combustion of PM according to the present embodiment.
4 shows the change in the reactivity of catalytic combustion of a carbon particulate material according to a change in _{O 3 concentration.}
5 shows a change in the reactivity of catalytic combustion of a carbon particulate material according to a change in _{NO 2 concentration.}

In the present invention, various modifications may be made and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail.

However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

1 is a diagram showing a system for removing carbon particulate matter through the addition of nitrogen oxides according to an embodiment of the present invention.

As shown in FIG. 1, the apparatus for removing carbon particulate matter according to the present embodiment may include a mixer and a combustion reactor (filter).

The exhaust gas containing carbon particulate matter, nitrogen monoxide, and ozone are introduced into the mixer according to the present embodiment, and nitrogen dioxide and ozone are discharged.

In the mixer according to the present embodiment, nitrogen monoxide and ozone are supplied at a stoichiometric ratio of 1:1 to convert the nitrogen monoxide into nitrogen dioxide and discharge it.

For the ozone generating system with low power consumption, according to the present embodiment, a dielectric barrier discharge (DBD) reactor, which is one of the low-temperature plasma methods, is used.

The nitrogen dioxide and ozone discharged from the mixer are introduced into the combustion reactor coated with the catalyst. The filter according to the present embodiment collects carbon particulate matter and discharges carbon dioxide through a catalytic reaction with nitrogen dioxide and ozone.

In this embodiment, nitrogen monoxide is supplied and converted into nitrogen dioxide through reaction with ozone (Reaction 2), and then supplied to the particulate matter combustion reactor corresponding to the filter, and ABO ₃ (A = La, B = Mn) Alternatively, by attempting to burn the carbon particulate matter by ozone in the state where the perovskite catalyst of the _{A 2} BO _{4 structure is applied (Reaction 3), the combustion reaction rate of the carbon particulate matter is improved.}

[Scheme 2]

O ₃ (g) + NO (g) → NO ₂ (g) + O ₂ (g)

[Scheme 3]

NO ₂ (g) + O ₃ (g) + C(s) → CO ₂ (g) + O ₂ (g) + NO

The perovskite catalyst according to this embodiment may have an ABO ₃ or A ₂ BO ₄ structure.

Here, the A site is selected by a mixture of one or two or more metals of La, Pr, Ce, Sr, Ba, Li, K, and Mg, and the A site has one of the metals as a main component, and the main component is It can be partially substituted with one of the remaining metals.

In addition, the B site may be selected from one of Mn, Fe, Co, Zr, Cr, Ti, Cu, and V, or a mixture of two or more metals.

The B site has one of the metals as a main component, and the main component may be partially substituted with one of the other metals.

Hereinafter, _{examples of the ABO 3} structure perovskite catalyst will be described in detail.

[Example 1] ABO ₃ Synthesis of structured Perovskite catalyst (A = La, B = Mn)

The metal acetate aqueous solutions of the A site and B site metals constituting the catalyst were prepared at a certain concentration, and the aqueous solutions were mixed according to the stoichiometric ratio for each element of the catalyst to be synthesized, and then stirred at room temperature for 30 minutes. Citric acid in the same amount as the metal ion may be added in the aqueous solution preparation step. The agitated solution was evaporated to dryness at 50℃ to obtain a particulate precipitate, followed by drying at 120℃ for 24 hours under air conditions, primary firing at 400℃, and secondary firing at 950℃, followed by an ABO ₃ type catalyst. Was prepared.

[Example 2] Search of ozone concentration maintenance section

In the conditions of ozone (O ₃ ) concentration of 2,500 ppm and reactor flow rate of 300 cc/min, the _{change in O 3} concentration was observed while increasing the temperature from room temperature to 3° C./min.

Figure 2 shows the results of the thermal decomposition experiment of ozone, the reactor: O ₂ 10%, O ₃ 2500 ppm, N ₂ balance. 300 cc/min; It shows the change in the concentration of ozone at a temperature rise rate of 3℃/min.

Confirmed that the temperature began to occur O ₃ conversion (O ₃ Conversion) from 100 ℃ the temperature is increased ozone conversion rate while continued to rise O ₃ conversion rate is all thermally decomposed 100%, that O ₃ reaches 300 ℃ according to Could.

Therefore, _{the temperature at which the O 3} concentration is maintained so _{that the combustion reaction of carbon particulate matter by O 3} can be expected is less than 300°C.

[Example 3] ABO of carbon particulate matter according to change in ozone concentration ₃ Catalytic combustion reaction

A particle mixture obtained by mixing 10 mg of carbon particulate matter and 20 mg of ABO ₃ (A=La, B=Mn; hereinafter LaMnO ₃ ) as a catalyst material was charged in the center of a cylindrical quartz reactor (particulate combustion reactor). To the front end of the reactor, NO was supplied to a concentration of 250 ppm, and 250 ppm O ₃ was supplied to convert all of NO into 250 ppm NO _2. Alternatively, 250 ppm of NO ₂ may be supplied directly without going through this step. In this state, O ₃ was additionally supplied, and the combustion reaction of the carbon particulate matter was performed at each concentration while gradually changing the _{O 3 concentration in the reactor body to 500, 1250, 1500, and 2500 ppm.} The reactor body contained 10% of oxygen (O ₂ ) in addition to NO and O ₃ , and the total flow rate was 300 cc/min.

3 is a diagram showing the configuration of a DBD plasma reactor for generating ozone to be used for low-temperature combustion of PM according to the present embodiment.

The electrode of the plasma reactor was made of SUS mesh and Cu rod, and a quartz tube was used as a dielectric material. The power supplier used for power supply has a frequency range of 50 Hz to 1 Khz, a primary voltage range of 0 to 15 Kv, and a maximum power of 300 W. The current was observed.

4 shows the change in the reactivity of catalytic combustion of a carbon particulate material according to a change in _{O 3 concentration.}

In Figure 4, the fixed bed: carbon particulate matter (Printex-U) 10 mg + LaMnO ₃ 20 mg: reactive body: NO ₂ 250 ppm, O ₂ 10%, O ₃ 500, 1250, 1500 or 2500 ppm, N ₂ balance. 300 cc/min; The temperature rise rate is 3°C/min.

Referring to FIG. 4, it can be seen that the combustion reaction of carbon particulate matter by _{O 3} proceeds as the generation of carbon monoxide (CO) and carbon dioxide (CO _{2 ) is detected in a temperature range below 300° C. where the O 3 concentration is maintained.} . It was confirmed that as the O ₃ concentration increased to 500, 1250, 1500, and 2500 ppm, the combustion reaction of carbon particulate matter in the temperature range below 300°C proceeded at a faster rate, and _{the concentration of generated CO and CO 2 increased.}

[Example 4] ABO of carbon particulate matter by ozone by addition of nitrogen monoxide ₃ Improvement of catalyst combustion reaction rate

_{In the same manner as in Example 3, the O 3} concentration was fixed at 2500 ppm in the packed bed in which 10 mg of the carbon particulate material and _{20 mg of the LaMnO 3 catalyst were mixed, and the NO 2} concentration was changed to 0, 250, 500, 1250, 2500 ppm. Reaction experiments were carried out. (As in Example 3, the O ₂ concentration was 10%, and the flow rate of the reactor was 300 cc/min.) The NO _{2 concentrations respectively set here directly supply the NO 2} gas capable of achieving the corresponding concentration, or the NO gas and It can be implemented by reacting _{O 3} with a 1:1 stoichiometric ratio or more.

5 shows a change in the reactivity of catalytic combustion of a carbon particulate material according to a change in _{NO 2 concentration.}

In Figure 5, fixed bed: carbon particulate matter (Printex-U) 10 mg + LaMnO3 20 mg: reactive body: NO2 0, 250, 500, 1250, or 2500 ppm, O2 10%, O3 2500 ppm, N2 balance. 300 cc/min; The temperature rise rate is 3°C/min.

Referring to FIG. 5, it can be seen that when NO ₂ is not contained (0 ppm), the concentration _{of CO and CO 2} is increased under conditions of 250 and 500 ppm _{NO 2.} When the NO ₂ concentration is 1250 and 2500 ppm, the combustion reaction performance (CO, CO _{2 concentration level) decreased rather than the NO 2} 0 ppm. This is because the catalyst _{adsorbs O 3 as excessive NO 2} is adsorbed on the catalyst. This is because it interferes with the action of producing activated oxygen.

_{Therefore, it was found that when supplying nitrogen dioxide (NO 2} ) at a concentration corresponding to 500 ppm, which is 10% or 250 ppm to 20%, compared to 2500 ppm of ozone concentration, it is possible to improve the speed _{of the ABO 3} catalyst combustion reaction of carbon particulate matter by ozone. I can.

That is, when the concentration of nitrogen oxide is in the range of 0.1 to 0.2 compared to the ozone concentration, it can be seen that the combustion reaction rate is improved.

Or NO ₂ instead of supplying the nitrogen monoxide (NO) in the same concentration and stoichiometric ratio 1: 1 can be reacted with an ozone concentration of more than expected, the same effect also by NO ₂ supply.

The above-described embodiments of the present invention are disclosed for the purpose of illustration, and those skilled in the art who have ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes and additions It should be seen as falling within the scope of the following claims.

Claims (6)

As a carbon particulate matter removal system through the addition of nitrogen oxides,
An atmospheric low-temperature plasma reactor for supplying ozone generated through an oxidation reaction of oxygen or air; And
A carbon particulate matter removal system including a combustion reactor filled with a perovskite catalyst having an ABO ₃ or A ₂ BO ₄ structure and combusting carbon particulate matter using ozone and nitrogen oxide supplied to the atmospheric low-temperature plasma reactor . The method of claim 1,
The carbon particulate matter removal system further comprises a mixer disposed at the front end of the combustion reactor and supplying nitrogen monoxide and ozone at a stoichiometric ratio of 1:1 to convert nitrogen monoxide into nitrogen dioxide and discharge it. The method of claim 1,
The nitrogen oxide supplied to the combustion reactor is a carbon particulate matter removal system having a concentration range of 0.1 to 0.2 compared to the ozone. The method of claim 1,
The carbon particulate matter removal system in which the low-temperature combustion of the carbon particulate matter is performed within a range of 100 to 300°C. The method of claim 1,
The atmospheric pressure low-temperature plasma reactor is a dielectric barrier discharge (DBD) reactor for removing carbon particulate matter. As a carbon particulate matter removal system through the addition of nitrogen oxides,
A mixer in which nitrogen monoxide and ozone are supplied at a stoichiometric ratio of 1:1 to convert nitrogen monoxide into nitrogen dioxide and discharge it; And
A carbon particulate matter removal system comprising a combustion reactor that is filled with a perovskite catalyst having an ABO ₃ or A ₂ BO _{4 structure and burns the carbon particulate matter using ozone and nitrogen dioxide converted in the mixer.}

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